No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Foundation-structure systems over a rupturing normal fault: Part I. Observations after the Kocaeli 1999 earthquake
Abstract
Triggered by reactivation of the strike-slip North Anatolian Fault, the disastrous M
w
7.4 Kocaeli (Turkey) earthquake also produced normal faulting in the pull-apart basin of Gölcük. Surface scarps from such faulting reached almost 2.5 m in height. Several structures were crossed by the surface rupture. As expected, many of them either collapsed or were severely damaged. But, surprisingly, several structures survived the outcropping dislocation essentially unscathed. In fact, in some cases the surface rupture path seemed to have deviated, as if to “avoid” rupturing directly underneath a structure. In other cases damage was substantial even though the fault rupture was “masked” by the near-surface soil and did not create a scarp. The rigidity and continuity of the foundation appears to have been one of the crucial factors affecting structural performance. Interestingly, the examined structures were supported on a variety of foundation types, ranging from isolated footings, to rigid box-type foundations, to piled foundations. The paper outlines a reconnaissance of the area, providing a documented description of the observed interplay between the rupturing fault, the soil, and the structure, along with the results of soil exploration and geological trenching. In the companion paper, Part II, each system is analysed numerically to confirm the conclusions of the present paper, reveal the main aspects of Fault Rupture-Soil-Foundation-Structure Interaction (FR-SFSI), and help develop deeper insights into the mechanics of successful performance of structures built on top of such faults.
... Dipslip faults are inclined fractures where the bedrock movements make the mass above the bedrock experience an inclined upward displacement (reverse faulting) or inclined downward movement (normal faulting). Deep and shallow foundations subjected to dip-slip faults are prone to failure, the possibility of failure, and/or the reduction of their performance level [3]; Faccioli et al., 2008). Many researchers have attempted to conduct studies on the interaction between shallow/deep foundations and dip-slip faults and tried to determine the failure mechanism as well as the behavior of foundations using experimental modeling [4][5][6][7][8][9][10][11], numerical modeling [12][13][14][15][16], and field surveys [3,17,18]; Faccioli et al., 2008; [19]. ...
... Deep and shallow foundations subjected to dip-slip faults are prone to failure, the possibility of failure, and/or the reduction of their performance level [3]; Faccioli et al., 2008). Many researchers have attempted to conduct studies on the interaction between shallow/deep foundations and dip-slip faults and tried to determine the failure mechanism as well as the behavior of foundations using experimental modeling [4][5][6][7][8][9][10][11], numerical modeling [12][13][14][15][16], and field surveys [3,17,18]; Faccioli et al., 2008; [19]. Faccioli et al. (2008) concluded from field investigations that buildings subjected to dip-slip tectonic movements might experience different levels of damage, from negligible damage to severe failure. ...
... One of the most important pieces of evidence gained from field investigations on the interaction of normal fault and pile foundations is the normal fault-induced damage of the Ataturk basketball building during the devastating earthquake of Kocaeli in 1999 in Turkey. In this particular case, bending cracks were observed near the head of some piles located in the corners of the building after being hit by the normal fault rupture [3]. Other studies have revealed that the place of pile foundations relative to the SFR and the level of vertical displacement of the bedrock are two crucial factors in the performance of pile foundations subjected to normal faults [10,15]. ...
Recent earthquakes leading to the emergence of surface fault rupture (SFR) on the ground surface have indicated disastrous damage to buildings. As avoidance is not always possible, proposing mitigation strategies have become quite popular with geotechnical engineers. Given that the performance benefits of helical piles outweigh other piles, the present study investigates the possibility of using cushioned helical-piled raft systems close to active normal faults to mitigate fault-induced deformations. An experimentally validated finite element code considering the critical state of the sand is implemented in this study. The response of cushioned helical-piled raft system to different distances of the raft of the system from the SFR is studied comprehensively, and the results are compared with a cushioned pipe-piled raft system with the same ultimate bearing capacity. The results reveal the superiority of using cushioned helical-piled raft systems in the vicinity of an active normal fault in terms of reducing raft rotation up to nine times, as well as lower values of the fault-induced structural response of the piles. Also, a parametric study on the geometrical aspect of helical piles shows that fault-induced angular rotation of the raft is highly dependent on it.
... If a fault rupture propagates to the ground surface and causes excessive ground deformation, it can endanger human lives and engineering structures (including bridges, highways, buildings, and utilities). Several field case histories have reported the damage of structures due to faulting in recent earthquakes [1][2][3][4][5]. Hence, researchers and designers have attempted to find the best mitigation method to protect foundations from significant rotation when they are located around active fault zones. ...
... The type, continuity, and rigidity of the foundation systems, ranging from isolated footings, box-type to pile foundations, have a major effect on the structure's response due to emerging dislocations. Furthermore, it has been observed that the effect of the superstructure's surcharge load on the foundation rotation is equally important, since higher stress under the foundation increases the capability of the foundation to divert the fault rupture path [2][3][4]. Due to numerous cases of devastating effects of earthquake surface fault rupture on structures, researchers have conducted extensive experimental, analytical, and numerical studies to understand the interaction between rupturing dip-slip (normal or reverse) faults and a variety of foundation types [6][7][8][9][10][11][12]. Bransby et al. conducted a series of centrifuge tests to model the effect of reverse fault rupture on the foundation rotation and reported several important parameters, such as footing breadth, footing type, surcharge load, relative density of soil, and fault position [13]. ...
... Finally, this method is only applicable for cases where the exact fault discontinuity location and direction of the fault dip angle are known, and it is not recommended when the fault path is not completely known. Since the faulting dip angle direction and fault discontinuity location are typically unknown during earthquakes [2][3][4]29], this method has a very limited usefulness for mitigating the risks of the reverse faulting effect on foundations. ...
This research presents the pros and cons of two previous mitigation methods to protect a building foundation from reverse fault rupture and then, for the first time, proposes a novel mitigation method, including a V-shaped concrete element under a shallow foundation, to reduce the foundation rotation caused by a fault rupture. The results of this study indicate that previously suggested methods, such as the presence of a weak wall next to the foundation or a strong inclined wall beside a weak vertical wall, are not suitable for unknown fault conditions, and the foundation rotation may be the same or worse than an unprotected foundation when the worst-case scenario of the discontinuity location and dip angle of the fault exists. The new effective approach diverts the rupture path and reduces the foundation rotation for the worst discontinuity location and fault dip angle by approximately 3.5° compared to the previous methods. In other words, where the discontinuity location and dip angle of the fault are unknown, using a V-shaped concrete element under the foundation is a more appropriate and effective mitigation method for structures. The results also show that the inclination angle of the V-shaped element is an important parameter compared to other parameters.
... Fault deformation during earthquakes can cause severe damages to structures, such as houses, bridges, dams, tunnels, and pipelines. Previous earthquakes occurred in 1999 (Chi-Chi earthquake, Taiwan; Kocaeli and Düzce earthquakes, Turkey) and 2008 (Wenchuan earthquake, China) provided many such instances [1,14,20,28]. The damages of structures caused by faulting had motivated many studies to explore the fault rupture propagation in overlying soil (e.g. ...
... The relief shelf is applied to reduce the rotation of the diaphragm wall. Numerical analyses were performed using the constitutive soil model with strain softening developed by Anastasopoulos et al. [1]. The objectives of the study are 1) to investigate the interaction mechanisms between rigid diaphragm wall (RDW) and normal faulting, 2) to exam the effects of the relief shelf on the stability of the diaphragm wall; and 3) to explore the protection effects of RDWRS on the foundation and discuss som influence factors. ...
... is the mesh size. The constitutive soil model was proposed and thoroughly validated by Anastasopoulos et al. [1]. According to Tatsuoka et al. [33]; the ϕ p , ϕ res , ψ p , ψ res , and γ s (unit weight) can be taken as 41°, 30.2°, 13.5°, 0°, 15.1 kN/m 3 (listed in Table 2), respectively. ...
Previous studies developed several types of weak and soft walls to deviate reverse fault ruptures and to absorb the compressional soil deformation. However, different strategies are required to address the extensional soil deformation caused by normal faulting. This study proposes a rigid diaphragm wall with a relief shelf (RDWRS) to mitigate soil and shallow foundation deformations in normal fault. The relief shelf is applied to keep the stability of the diaphragm wall and to protect the shallow foundation on the ground surface. Numerical modeling is performed to investigate the diaphragm wall-normal fault interaction mechanisms and the effects of RDWRS on deformation mitigation of shallow foundations. The RDWRS shows promising effects concerning the mitigation of soil and shallow foundation deformations. The protection effects depend on soil depth, foundation width, foundation location, surcharge pressure, wall depth relative to the rupture, the width of the relief shelf, and the distance between the wall and the foundation. As this paper presents the results of numerical modeling, experimental studies are suggested for future studies. Besides, the economy of the RDWRS should be comprehensively considered when applying this method.
... Typically, after a severe earthquake, if the foundation system is aggravated, it requires a lot of time to restore [62][63][64][65][66]. In many cases, demolition (in other respects, of a lightly damaged building) occurs because of the damage, tilting, or sliding of the foundation [67]. ...
... Generally, foundation damage is irreversible [68]. Consequently, for an ERnZEB building it is of paramount importance that it is founded on a stable soil (this requires a thorough geotechnical investigation study primarily for the soil characterization and, after that, for the calculation of the bearing capacity not from the soil's capacity but from its deformation capacity); moreover, in cases of near field earthquakes, especially within a radius of approximately 10 Km from the epicenter, as well as in the case of nearby rivers, lakes, sea, the foundation system must be rigid, continuous on the soil foundation, and of box type, with circumferential rigid reinforced concrete walls [62,63,69,70] (i.e., piled raft foundations, piled cap foundations connected with rigid grade beams forming grids, box-type basements, on approximately 3 m depth, with raft foundation, cellular rafts filled with sand). Alternative solutions to protect the foundation system would be the construction of a soil bentonite walls in near proximity to the building [71,72], the execution of vertical trenches of extruded polystyrene sheets [73], or a design of the foundations according to the rocking isolation concept [74][75][76]. ...
The climate crisis, the need for a circular economy, and the large financial losses after earthquakes have promoted the concept of the sustainable and resilient design of societies, and more specifically, of lifelines and building environments. Focused on building facilities, it is imperative to prescribe, within the aforementioned framework, the components that characterize earthquake resilient near zero energy buildings (ERnZEBs). Through a conceptual analysis, the goal is to discuss the attributes and perspectives of ERnZEBs within the framework of the view of a designer engaged in practice. This fact introduces an additional factor recognizing that not all projects have the same technical and financial values; the difference in budget, the type of owner, and the investment (private or public, company or private person) play important roles in creating an ERnZE building. In this direction, this paper reviews the basic principles of ERnZEBs, providing a combination of pragmatic considerations while also exploiting the state of the art and practice of current engineering knowledge.
... This fault passed through several urban regions and inflicted damage to bridges, vital lines and buildings [7,8]. Shear rupture and angular distortion are two main components affecting surface faulting [9][10][11][12]. ...
... In recent decades, numerous studies have been conducted on foundation-fault rupture interaction and faulting simulation, including the use of case histories from past earthquakes [1,[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24], physical modeling [23,[25][26][27][28][29] and numerical analysis [29]. The majority of earlier studies which were concerned with geological investigation and to understand the effect of faulting of structures were carried out using sandbox models [30]. ...
Surface fault ruptures damage structures which are located at the intersecting zones of active faults. It is essential to consider the undesirable effects of surface fault ruptures when designing structures. Geotechnical measures such as reinforced soil foundations effectively mitigate the hazards related to surface faults. The present work conducted a series of tests on foundations reinforced with geosynthetics, including geogrids, geocells and geogrid-geocell layers. These tests simulated the behavior of 1.5 m-wide strip footings located in 6-m thick alluvium that had been displaced 60 cm. A total of 12 disparate tests in terms of the number and type of reinforcement were conducted at a scale factor of 10. Image analysis of the results indicated desirable behavior for reinforced soil foundations in terms of reduced angular distortion, uniform settlement and deviation of the fault path. For normal fault rupture, the angular distortion of foundations reinforced by one geogrid layer, one geocell layer, one geogrid-geocell layer or two or three geo-grid layers decreased by 60%, 30%, 70%, 80% and 80%, respectively. These results also revealed that an increase in the number of geogrid layers to more than two layers caused an insignificant decrease in angular distortion. The decrease in angular distortions observed for soil foundations reinforced by one geogrid layer, one geocell layer and one geogrid-geocell layer were 7%, 16% and 40%, respectively, for reverse faulting. The performance of a reinforced soil foundation subjected to normal faulting was more acceptable than that for reverse faulting.
... Recently, offshore energy sector used suction caissons as support structures in seismically active areas, while the response under seismic loads is not well understood in contrast to the well-studied response against environmental loads (Barari et al. 2012). In a seismic event, the rupture of an earthquake fault generates two types of ground displacement; permanent quasi-static offsets on the fault itself and transient dynamic oscillations away from the fault (Anastasopoulos & Gazetas 2007a). ...
... In fact, Anastasopoulos & Gazetas (2007a) performed a case study in several structures with various superstructure systems and foundations close to an approximately 2 meters normal fault. It is noteworthy to mention that even the initial faulting mechanism was strike-slip, it locally converted into a normal fault. ...
This paper presents the results of numerical simulations, which allow for the description of the interaction mechanism of a tripod suction caisson foundation with reverse fault rupture. The numerical and soil models are verified against well-documented Finite Element (FE) analysis and centrifuge experiments in terms of free field vertical displacement at the soil surface. Then, a series of parametric studies with varying foundation positions with respect to the free field fault rupture outcrop location was carried out. The obtained results revealed that the presence of the structure bifurcates the fault rupture and forces it to outcrop outside of the margins of the foundation. Numerical results indicate that the tripod foundation system may undergo significant horizontal displacements and structural rotations, depending on the unit caisson position with respect to the fault rupture trajectory.
... In 1999, three catastrophic earthquakes with extended surface displacements: Kocaeli and Duzce earthquakes in Turkey and Chi-Chi earthquake in Taiwan, have caused an increased interest on this subject. The M w 7.4 Kocaeli earthquake caused surface displacements up to 5 m along approximately 140 km, which caused damages in buildings, mosques and other infrastructure (Anastasopoulos and Gazetas, 2007a;Sahin and Tari, 2000). The M w 7.2 Duzce earthquake caused both horizontal and vertical displacements of the order of 3 m and 5 m, respectively, in an area of about 45 km in length (Sahin and Tari, 2000). ...
... Field studies, as well as experimental and numerical approaches, have been used to investigate the above phenomenon. Field studies include the investigation of rupture patterns through soil deposits (Bray et al., 1994a;Dobrev and Košt'ák, 2000;Lade et al., 1984;Loukidis et al., 2009) or the impact on adjacent structures and infrastructure (Anastasopoulos and Gazetas, 2007a;Dong et al., 2003;Faccioli et al., 2008;Kelson et al., 2001;Zhang et al., 2013). Such findings can be compared with numerical or experimental models. ...
The increasing urban development in seismic-prone regions, in conjunction with the continuous construction of large-scale lifelines (i.e., road and railway networks, pipelines, etc.) has increased the risk of potential damages due to permanent displacements at the ground surface that can be caused by an earthquake fault rupture. Several recent earthquakes have revealed this risk. Therefore, the problem of fault rupture propagation of a single fault has been thoroughly investigated with field studies, as well as experimental tests and numerical models. Nevertheless, the presence of parallel or intersecting secondary fault ruptures is usually observed in the field due to stress redistributions and/or rock heterogeneities. The aim of the current study is to examine the rupture patterns and surface displacements caused by the contemporaneous rupture of a main fault and a perpendicular secondary fault. A three-dimensional numerical model has been developed utilizing the finite-element method in order to examine this complex phenomenon in sandy deposits. The soil behavior is represented quite accurately via an elastoplastic Mohr-Coulomb constitutive model with isotropic strain softening, which is initially validated with experimental results obtained by centrifuge tests in case of a single fault. Subsequently, a detailed parametric study has been performed, investigating different fault types and dip angles, as well as sandy layer thickness and material properties, to highlight various important aspects regarding the development and propagation of secondary fault ruptures and the resulting zones of excessive surface displacements.
... Field studies on the interaction between various types of buildings with permanent fault deformation demonstrate that the degree of destruction due to the fault-structure interaction depends on many factors, such as magnitude of fault movement, faulting type, footing type, distance from fault projection, continuity and rigidity of the foundation system, and stiffness of the structure [2][3][4][5][6][7][8]. Chen et al. [2] and Dong et al. [4] observed that most of the buildings damaged during the Chi-Chi earthquake were located near the Chelungpu fault. ...
... (Taiwan, 1999) [4] b. Severely damaged building in Chi-Chi earthquake (Taiwan, 1999) due to rupture with 10 cm uplift in soil surface [4] c. Building damage and squeezing of the first floor due to Chelungpu surface uplifting after Chi-Chi earthquake (Taiwan, 1999) [2] d. Deformation of two-story building after interaction with reverse fault, with 1.5 m vertical offset in Chi-Chi earthquake [11] e. Loss of two of four high-voltage electricity pylon supports after interaction with normal rupture and vertical dislocation of approximately 1.5 m in Kocaeli earthquake (Turkey, 1999) [5] f. Differential settlement of 1.3 m of a mosque with separate footings without connection between them, after interaction with normal rupture in Kocaeli earthquake (Turkey, 1999) [5] Fig. 1 ...
Investigations on the effects of fault permanent deformations on surface and subsurface engineering structures are important owing to their direct impact on the reduction of earthquake damage. This study presents the methodology and results of a comprehensive, three-dimensional, nonlinear numerical modeling of the interaction between dip-slip faulting in soil and a four-story steel moment frame structure founded on different types of shallow surface foundations. A modified Mohr–Coulomb constitutive model was implemented in the numerical modeling, where the softening/hardening behavior of soil and an elasto–plastic model that provided a more accurate description of the stress–strain response of steel elements were considered; both were adopted in a finite element program. The results demonstrate that modeling the structural elements, in comparison with only modeling the footing as a rigid plate and compromising the effect of the structure by applying its weight, significantly affects the soil–structure interaction and displacements of the footings. The results indicate that a strip footing oriented perpendicular to a fault strike yields results similar to a mat footing, whereas a strip footing parallel to a fault strike resembles a spread footing. This suggests that not only the stiffness of the footing to tolerate the vertical loads of the structure, but also its continuity or freedom to move in the direction of fault displacement is important. In the absence of rigid connection between structure footings, the excessive freedom of a footing to comply with the quasi-static deformation of soil due to fault-induced movements results in a considerable deformation and rotation of the columns, primarily in the columns between the footing and the first floor.
... Research efforts have so far focused on: (a) the documentation and analysis of case histories of structures subjected to faulting-induced deformation [2][3][4][5][6][7]; (b) physical modeling of foundations interacting with fault ruptures [8][9][10][11][12][13][14][15][16]; and (c) numerical and analytical studies on the effects of fault rupture propagation on foundation-structure systems [13,[17][18][19][20][21][22][23] and (d) development of mitigation techniques [24][25][26][27][28]. Researches on fault-foundation structure have shown that response of slab foundation may be better with loose sand compared to dense sand according to Anastasopoulos et al [20], illustrating the effect of soil stiffness on response of foundation subjected to reverse fault rupture. Thoroughly validated finite element (FE) models (e.g. ...
... It has been shown that the response of a foundation-structure system is a function of: (i) its location relative to the fault outcrop; (ii) soil conditions, including material properties and soil deposit thickness; and (iii) the foundation surcharge load [16,20]. More advanced studies on fault-structure interaction have been carried out on series of structures with simplified 2D analysis and examination of case history events showing that heavily loaded structures founded on continuous and rigid foundations may divert the fault rupture [3,4,17]. ...
The paper studies the response of a 3-storey building subjected to reverse faulting. 1 g physical model tests are conducted using a 3 m long split-box, modelling the nonlinear response of structural members with artificial plastic hinges. The experimental results are used to validate the numerical modelling technique, which is subsequently employed to conduct a parametric study on sand density, foundation type (isolated footings, strip and slab foundations), and the location and angle of fault crossing. It is shown that the response of the structure is sensitive to the relative location of the fault rupture. In the case of isolated footings, complex interaction mechanisms develop, including fault rupture diversion, bifurcation, or diffusion. While the rigid-body rotation of the structure θ r is crucial in terms of serviceability, the footing rotations θ f are responsible for superstructure distress. Such distress is directly related to differential footing rotations and displacements. Looser soil may act as a cushion, but its effect is not always beneficial. Bifurcation of the fault rupture may lead to outcropping of a secondary branch between the footings, with obvious detrimental consequences. Strip footings or a slab foundation offer substantial improvement. Such rigid and continuous foundation systems prohibit differential displacements between columns, forcing the entire structure to rotate as a rigid body. The interaction mechanisms are complicated further when the fault rupture crosses the structure at an oblique angle. The distress of the structure is reduced with strip footings, which should be installed in both directions.
... Earthquake waves may pose a significant destructive impact on large surface areas and hence have been the sole focus of numerous studies throughout the literature (Gazetas 1982;Zeng and Steedman 2000;Jamshidi Chenari et al. 2016Senetakis and Payan 2018;Izadi et al. 2019;Hemmati Masouleh et al. 2019;Rezaie Soufi et al. 2021;Zamanian et al. 2021;He et al. 2021). On the other hand, the displacements induced by fault rupture propagation throughout the soil medium could also be severely destructive resulting in substantial ground movement and structural deformation (Anastasopoulos and Gazetas 2007aGazetas , 2007bAnastasopoulos et al. 2007Anastasopoulos et al. , 2008Anastasopoulos et al. , 2009Bungum 2007;Bransby et al. 2008aBransby et al. , 2008bBaziar et al. 2015;Liu et al. 2018;Anastasopoulos and Agalianos 2019;Li et al. 2021;Firouzeh et al. 2022;Ashouri Nalkiashari et al. 2022). ...
In this study, the interaction of reverse fault rupture outcrop with rigid strip foundations overlying a sand deposit is examined using the well-established method of upper bound limit analysis in conjunction with the finite element discretization and linear programming technique. The results of the numerical analyses are compared with the experimental works in the literature, and a qualitatively satisfying agreement is observed. The verified numerical approach is then implemented to perform a parametric survey on the interaction of a reverse fault rupture outcrop with a rigid strip footing resting on a granular soil deposit. Accordingly, the influences of several parameters, including the foundation width, the service bearing pressure, the soil shear strength parameters, the fault throw, the dip angle of the fault offset, and the relative distance between the foundation and the fault rupture dislocation, on the rotation rate of strip footing are thoroughly examined and discussed. The findings of the study show that the foundation rotation increases with the increase in the amount of fault throw on the bedrock and along the fault path. In addition, it is observed that increasing the foundation width, surcharge loading, and fault dip angle as well as decreasing the internal friction angle of the soil medium lead to an overall reduction in the angular distortion of the shallow foundation for almost all cases under study. The superb efficiency of the two main mitigation schemes, including the EPS wall and soil-bentonite wall, to divert the mainstream of the fault rupture from the overlying foundation is also depicted and discussed.
... Tunnels are widely used in mountainous regions because of their resilience against geological and seismic hazards, but may sometimes need to traverse weak or faulting zones [28][29][30][31][32][33][34]. Recent earthquakes, such as the 1999 Chi-Chi, 1999 Kocaeli, and 2008 Wenchuan earthquakes, have caused significant destruction to tunnels despite their higher earthquake resistance than surface buildings [34][35][36][37][38][39][40]. ...
The tunnel boring method (TBM) is a widely used and effective tunneling technology in various rock mass quality circumstances. A “faulted rock mass” can range from a highly fractured rock mass to a sheared weak rock mass, making the ground conditions challenging for tunneling, especially for TBMs. “Faulted rock” significantly affects hard rock TBMs, primarily due to the TBM’s high geological risk and poor flexibility. TBMs require careful planning and preparation, starting with preliminary assessments. This study investigates the impact of establishing an isolation material between a circular tunnel and the adjacent faulting rock on seismic response. The two parts of the parametric analysis for the isolation material utilized in the model look at how changes in the mechanical characteristics of the material, such as the shear modulus of the rock and the fault, affect the stresses created in the tunnel. The second section examines how changes in the isolation width concerning the fault width affect the stresses and displacements produced in the tunnel. Additionally, the effectiveness of isolating the tunnel during sudden changes in the characteristics of the rock was investigated under seismic loading perpendicular to the tunnel and parallel to the tunnel. The finite element approach was utilized to model the TBM tunnel and the neighboring rock with a fault or sudden change in the rock using Midas/GTS-NX, simulating the interactions between the rock and the tunnel. Time-history analysis using the El Centro earthquake was conducted to calculate the stresses in the tunnels during seismic events. Peak ground accelerations between 0.10 g and 0.30 g were utilized for excitation. A time step of 0.02 s and a length of 10 s for the seismic event were used in the analysis, with traditional grout pea gravel vs. the isolation layer. Comparisons were made between the absolute stresses (the greatest possible values) in the normal tunnel section (Sxx) and those induced in the tunnel with traditional grout and with isolation. Furthermore, the study of vertical displacement was taken into consideration. The seismic isolation method is highly effective in improving the seismic safety of bored tunnels. The results show that the significant values of the ratio between the shear modulus of isolation and the surrounding soil should be between 0.2% and 0.4%. Where parts of the tunnel run through a fault, the effective length of isolation should be between one and two times the fault width. The dynamic behavior of the tunnel with isolation is better than that with traditional grout. Generally, when isolation is used for any length, it reduces the stresses at the area of sudden change. Consequently, engineering assessments from both structural and geotechnical engineering viewpoints are now required for these unique constructions. An underground structure’s safety should be evaluated by the designer to ensure that it can sustain various applied loads, taking into account seismic loads in addition to construction and permanent static loads. Tunnels may be especially vulnerable in areas where the composition of the soil or rock varies.
... The type of damage that occurred in the 1999 earthquakes in Turkey, the 2008 earthquake in China, and the Longmenshan fault, all of which created outcropping fault ruptures up to 9 m, have drawn many researchers' attention to this subject. However, several cases have shown that a building was able to deviate the fault rupture away from itself (Anastasopoulos and Gazetas, 2007a;Faccioli et al., 2008;Ulusay et al., 2002). Anastasopoulos and Gazetas (2007b) provided a documented explanation of the interaction between fault rupture, soil, and an engineering structure. ...
Evidence from recent earthquakes has shown destructive consequences of fault-induced permanent ground movement on structures. Such observations have increased the demand for improvements in the design of structures that are dramatically vulnerable to surface fault ruptures. In this study a novel connection between the raft and the piles is proposed to mitigate the hazards associated with a normal fault on pile-raft systems by means of 3D finite element (FE) modeling. Before embarking on the parametric study, the strain-softening constitutive law used for numerical modeling of the sand has been validated against centrifuge test results. The exact location of the fix-head and unconnected pile-raft systems relative to the outcropping fault rupture in the free-field is parametrically investigated, revealing different failure mechanisms. The performance of the proposed connection for protecting the pile-raft system against normal fault-induced deformations is assessed by comparing the geotechnical and structural responses of both types of foundation. The results indicate that the pocket connection can relatively reduce the cap rotation and horizontal and vertical displacements of the raft in most scenarios. The proposed connection decreases the bending moment response of the piles to their bending moment capacity, verging on a fault offset of 0.6 m at bedrock.
... There are other representative damage patterns, including fallen keystones from arches in Spain, Israel, Italy, and Mexico, particularly at archaeological sites (Rodríguez-Pascua et al., 2011;Korjenkov and Mazor, 2013;Martín-González, 2018;Pecchioli et al., 2018). Another common example is the fracturing of the walls or pillars of buildings, including single extensional fractures and conjugate shear fractures with diagonal patterns, which have been observed in many cases: the 1999 Chi-Chi earthquake, Taiwan (Bray et al., 2013); the 1999 Izmit (Kocaeli) earthquake, Turkey (Anastasopoulos and Gazetas, 2007); the 2005 Kashmir earthquake, India (Naseer et al., 2010); the 2008 Wenchuan earthquake, China (Zhou et al., 2009); the 2015 Nepal earthquakes (Dizhur et al., 2016); and the 2020 Puerto Rico earthquake (Hain et al., 2023). Most of these seismically induced damage patterns were interpreted as being due to predominantly horizontal earthquake ground motions. ...
Two recent moderate earthquakes in South Korea, the 2016 MW 5.5 Gyeongju earthquake and 2017 MW 5.4 Pohang earthquake, caused damages to modern residential buildings. These events occurred with almost the same magnitude and duration in the same seismotectonic environment but exhibited remarkably different focal depths, faulting types, surface deformation, and especially structural damage features, but the reasons for these contrasts remain unknown. Furthermore, the building damage patterns are different from the natural damages, which have typical patterns depending on the fault types. It is important to understand the key reasons of these different phenomena to prevent destructive hazards from future earthquakes, particularly in densely populated intraplate regions. Here, we reveal the relationships between the geological-seismic parameters and earthquake damage features based on the patterns of building damage associated with these two events. During post-event urgent field surveys, we systematically observed en-echelon (or Riedel-type) sub-horizontal fractures in building walls associated with strike-slip motion and high-angle conjugate X-shaped fractures in building walls associated with predominantly reverse oblique-slip motion. We attribute the different patterns of earthquake damage to variations in faulting types and associated ground motions; strike-slip faulting resulting in horizontal shear and oblique-slip faulting yielding vertical ground motion. We argue that these interesting characteristics of building damage are mainly caused by stress conditions depending on the environmental change from the underground crust to the ground surface of free face. Our study highlights the importance of post-event investigations of earthquake damage to improve the level of seismic hazard assessment. Our findings from this study could serve as a reference for establishing proper anti-earthquake design and reinforcement for seismic protection.
... To prevent the destruction of underground structures caused by active faults, active faults should be avoided as much as possible when selecting the route of freeway tunnels, railway tunnels, hydraulic tunnels and other linear structures. However, in practical engineering, especially in the western region of China, due to the limitations of route alignment, geological conditions, construction conditions and other factors, tunnels often inevitably cross active faults (Anastasopoulos and Gazetas 2007;Huang et al. 2013;Qu et al. 2019;Zhao et al. 2019). The permanent deformation caused by fault dislocation usually causes tensile, torsional and bending damage to the tunnel passing through the fault, and in serious cases, it may even cause a large deformation or overall collapse of the tunnel . ...
Tunnels crossing active faults can be severely damaged by fault dislocation. Based on a freeway tunnel crossing an active fault, a three-dimensional numerical model is established to investigate the influences of the friction coefficient and position of the dislocation surface on the tunnel response under the action of right-lateral strike-slip reverse fault dislocation. The results show that the friction coefficient of the dislocation surface has little effect on the deformation characteristics in the tunnel but has a slight effect on the stress distribution. As the friction coefficient increases from 0.3 to 1.0, the stress distribution shape in the tunnel basically remains unchanged, while the maximum absolute values of the principal stresses decrease. The dislocation position has a significant effect on the deformation and stress distribution in the tunnel. When the fault moves along the interface between the fracture zone and the intact rock mass in the hanging wall or footwall, the deformation of the tunnel is the most severe, and the local stress concentration is also the most severe. In view of the local damage, amongst the conditions studied here, the condition of fault dislocation occurring along the interface between the fracture zone and the intact rock mass is the most dangerous and the condition of dislocation occurring along the fracture zone is safest. Under fault dislocation, the tunnel deformation is the most obvious in the fracture zone and tends to decrease to both sides; the principal stress in the tunnel peaks in the fracture zone and decreases to the two sides. The tunnel may be seriously damaged in the fracture zone and fault walls within 5 m of both sides of the fracture zone, and the tunnel fortification length is 3.39 times the fault width of 90 m. Disaster mitigation measures should be adopted for the tunnel design within the fortification range.
... The behavior of overlying soil on the bedrock during faulting has become a major concern when designing structures within fault zones, as severe damages to structures were observed in historic earthquakes [2,5,17,24]. Previous studies had explored the mechanism of fault rupture propagation through field observation, statistical analysis, numerical simulation, and physical modeling [8,11,18]. ...
The mechanism of rupture propagation is fundamental to understanding the damage to structures within the fault zones. However, the traditional logarithmic spiral model could not describe some normal fault ruptures of physical tests. Therefore, this study conducted six centrifuge tests to give new insights into normal fault rupture propagation in the sand. The tests simulated normal faulting with dip angles of 60° in the free-filed condition, designed with different relative densities of sand and thicknesses of the overlying soil. The rupture propagation process and effects of relative density and soil thickness were discussed. The mechanism of normal rupture propagation in the sand was summarized, based on the test results. It is observed that two outcropping ruptures develop during normal faulting. The first one is a logarithmic spiral, with a surface angle of 45° + ψmax/2. However, its direction angle at the fault tip disagrees with the logarithmic spiral model. The second outcropping rupture experiences a combined trace due to the reduction in the dilation angle during faulting. The lower part follows a logarithmic spiral. The upper part propagates as a straight trace with an angle of 45° + φmax/2 when the dilation angle falls to the critical state. A slope forms on the ground surface, the angle of which is consistent with φres.
... Since then, the interaction of shallow foundations with the fault rupture outcrop at the ground surface has been examined in several studies, the majority of which have focused on the reverse faulting (Bray 2001;Anastasopoulos et al. 2007Anastasopoulos et al. , 2008Anastasopoulos et al. , 2009Gazetas 2007a, 2007b;Bransby et al. 2008b;Ahmed and Bransby 2009;Loukidis et al. 2009; Moosavi and Jafari (2012); Ashtiani et al. 2015, Baziar et al. 2015Anastasopoulos and Agalianos 2019;Firouzeh et al. 2022). Anastasopoulos and Gazetas (2007a) examined the catastrophic 7.4 M w earthquake in Kocaeli (Turkey) causing a natural fault in the Golçuk pull-apart basin reaching the ground surface. This study presented an identification of the area, providing a documented description of the observed interaction between fault, soil and structure, along with the results of the geological trench exploration. ...
Devastating influences of fault rupture outcrop on various geo-structures during past earthquakes have revealed the necessity of more detailed and comprehensive studies on the fault-foundation interaction. In this study, the interaction between the normal fault and shallow surface/embedded strip foundations is rigorously examined through a well-established upper bound limit analysis formulation in conjunction with the finite element discretization and linear programming technique. The adopted upper bound FELA method is shown to be efficient and cost-effective with high predictive capability, which can be easily implemented in any common computational platforms, like MATLAB. The accuracy of the adopted numerical method is first verified against some findings in the literature. Using this validated numerical approach, a comprehensive parametric study is performed to examine the interaction of the normal fault rupture outcrop with the surface and embedded shallow foundations. Accordingly, the influences of various parameters including the foundation breadth, the service footing pressure, the internal friction angle of the soil deposit, the foundation embedment depth, the fault throw and the relative distance between the fault rupture and shallow foundation, on the normal fault-footing interaction are systematically investigated and discussed. In addition, as an efficient retrofitting strategy to protect the shallow foundation against the fault outcrop, rigid mitigating barrier walls with different filling materials are proposed so as to divert the mainstream of the fault rupture and thus reduce its destructive effects on the overlying superstructures. In this regard, another parametric survey is carried out to explore the effects of wall-related geometric parameters, such as its depth, width, filling material and relative position, on the reduction of the destructive consequences of the normal fault rupture emergence at the ground surface. The results generally show that applying a rigid concrete wall with suitable height, width and distance from the foundation leads to the significant reduction in the amount of surface footing rotation subjected to normal fault rupture outcrop.
... Interestingly, there are also several case histories of structures that managed to survive large fault deformations with small or minimal damage, in some cases diverting the propagating fault rupture (e.g. Niccum et al., 1976;Anastasopoulos & Gazetas, 2007a, 2007bFaccioli et al., 2008). During the past two decades or so, significant effort has been devoted to understanding the mechanics of fault rupture propagation through soil and its interaction with foundations and structures, employing experimental (e.g. ...
The paper studies strike-slip fault rupture propagation through dense sand and its interaction with surface foundations, combining physical and numerical modelling. A series of centrifuge tests is conducted using a three-section split-box, which allows the modelling of two strike-slip faults per test. A free-field test is initially conducted, followed by four interaction tests. Eight different foundation configurations are studied, varying the foundation location, surcharge load, aspect ratio and rigidity. The experiments are numerically simulated employing three-dimensional finite-element modelling, combining periodic boundaries and a relatively simple yet efficient constitutive model, developed as part of this study. Based on a Mohr–Coulomb yield criterion, the model incorporates post-yield isotropic frictional hardening and softening (MC–HS). Carefully calibrated on the basis of triaxial tests, the model is validated against the centrifuge model tests, and exploited to derive further insights. The MC–HS model covers the entire range from elastic to fully softened response, capturing the deviatoric and volumetric behaviour of dense sand, and especially its pre-softening volumetric response, which is proven to be crucial for the simulation of the complex mechanisms of strike-slip faulting. Both physical and numerical modelling reveal the formation of diagonal shear ruptures at the ground surface (Riedel shears). These are complex helicoidal structures, formed due to the spatial variation of shear stresses. Foundation response is mainly governed by the kinematic constraint offered by its presence. Fault rupture locations close to its sides typically lead to a translational mechanism, whereas locations close to its centreline lead to a rotational one. Foundation rigidity is proven to be a prerequisite for the development of both mechanisms, which rely on the ability of the foundation to resist the developing normal and shear stresses.
... Recent major seismic events have provided several case histories of structures (buildings, bridges, dams, tunnels, and pipelines) severely damaged or collapsed due to faultinginduced deformation (e.g., [1][2][3][4][5]). In some cases though, structures that fulfilled certain criteria (e.g., foundation rigidity) managed to divert the propagating fault rupture, surviving the earthquake with minimal damage (e.g., [6][7][8][9]). ...
The paper investigates strike-slip fault rupture propagation through dense sand and its interaction with surface foundations, employing 3D finite element (FE) modelling. Two soil constitutive models (implemented in Abaqus through user subroutines) are employed for this purpose: (i) a recently developed simple yet efficient model with a Mohr-Coulomb yield criterion, which incorporates post-yield isotropic frictional hardening and softening (MC-HS model); and (ii) the basic version of the more sophisticated hypoplastic model for sand. Both models are calibrated on the basis of monotonic triaxial compression tests (and an additional oedometer test for the hy-poplastic model), conducted as part of this study. The numerical predictions are comparatively assessed against centrifuge model test results. In accord with the centrifuge model tests, the free-field analyses with the MC-HS model reveal a complex fault pattern at the ground surface, consisting of Riedel (R) shears. These are the sur-ficial manifestation of complex 3D structures of helicoidal geometry, attributed to the spatial variation of shear stresses within the overburden soil due to the imposed bedrock offset. The development of R shears is primarily controlled by the pre-softening volumetric soil response in monotonic compression and soil dilation. The latter is underestimated by the basic hypoplastic model, thus predicting the formation of a single straight shear band instead of R shears. A parametric study is conducted employing the validated MC-HS model, exploring fault rupture-soil-foundation interaction. Foundation response is shown to be sensitive to the surficial fault pattern (R shears vs. single fault trace), but the mechanism (rotational vs. translational) and foundation distress are not affected to the same extent. A two-step design strategy is outlined, requiring a free-field analysis to capture the surficial fault pattern, followed by a minimum of four interaction analyses, varying the fault-normal and fault-parallel foundation location.
... The 1999 Kocaeli earthquake demonstrated that the foundation of a structure plays a significant role in its response to the fault rupture path. Structures built over continuous, box-shaped foundations are considerably more efficient for diverting a fault rupture Gazetas, 2007a andGazetas, 2007b). Fig. 1 shows a four-story building with a basement located over a continuous, box-shaped foundation. ...
Understanding the cause of structural damage and loss caused by surface faulting rupture requires research on the fault rupture-foundation interaction and geotechnical mitigation methods. The present study investigated the interaction of reverse-faulting surface rupture and a foundation system comprising a mat foundation and micropiles. The effects of the micropiles on the rotation of the foundation and rupture propagation was examined for different interaction mechanisms. The results suggested that the response was sensitive to the position of the foundation micropiles. It was found that the position of the foundation-micropile system relative to the rupture determined the type of interaction between the soil, rupture, micropiles, and foundation, which is significant for development of geotechnical mitigation methods.
... In practice, crossing faults are inevitable in a tunnel project because of geological and circuit constraints [2,3]. Several studies have demonstrated that tunnel crossing faults can cause severe damage. ...
Crossing active faults has proven to cause significant damage in tunnels. In this study, a large–scale plate thrust model stimulating the LongMenShan Fault (LMSF) dislocation was established numerically. The characteristic dislocation curve of the fault generated at the stick-slip incidence was derived. Furthermore, a soil-structure FE model was established with a tunnel structure crossing the LMSF Zone, in which the hanging wall and footwall moved according to the abovementioned dislocation curve. To cope with the serious damage of tunnel caused by fault dislocation, the articulated design was adopted. For discovering an appropriate material to construct the articulated sections and enhance the flexibility of tunnel structure, basalt fiber reinforced concrete (BFRC) was studied by SEM test and mechanical tests. The results showed that basalt fiber could increase the tensile capacity and tenacity of concrete and the 0.5% BFRC was selected as the optimal fiber volume content. By applying the 0.5% BFRC articulated design, the length and width of tunnel cracks generated by fault dislocation decreased by 33.45% and 38.11%, respectively. This study could serve as a reference in the design of fault-crossing tunnel projects.
... The fault rupture propagation is one of the major concerns for structures located within the fault zone, as many structures were severe damaged due to faulting during previous earthquakes [2,13,16,23]. Tremendous efforts have been made to investigate the fault rupture propagation and fault-structure interaction. Centrifuge test plays an important role in studying the fault induced disasters due to the lack of well-documented field data [26]. ...
Centrifuge test plays a significant role in studying fault rupture propagation and fault-structure interaction. However, few previous studies have discussed the effect of boundary friction in centrifuge modeling of reverse faulting. This study reported four centrifuge tests to investigate the effect of boundary friction on rupture propagation of revere fault. The basic group of tests was modeled with a smooth sidewall and frictional bottom, while the observation group of tests was simulated with either a frictional sidewall or a smooth bottom. Rubber membrane and sandpaper were applied to make a frictional sidewall and bottom, respectively. The results indicate that the boundary friction affects the location of surface rupture and width of the shear band (major distortion zone). The side friction leads to a V-shaped or U-shaped surface rupture. The width of the shear band reduces with the increase of side friction. Less bottom friction results in a narrower fault zone and a broader shear band.
... Previous large earthquakes have shown that many human-made structures such as building, bridge, tunnel and pipeline were significantly damaged due to surface fault rupture or large ground deformation due to liquefaction (Youd et al. 2000;Pamuk et al. 2005, Anastasopoulos and Gazetas 2007, Rasouli et al. 2019. For instance, during the 1999 Duzce earthquake in Turkey, Bolu Bridge significantly damaged due to strike-slip surface fault rupture. ...
This paper presents the interaction mechanism of a 12-story building sitting on a piled raft foundation with a strike-slip fault rupture. The mechanical response of foundation including both structural and geotechnical response of the foundation are evaluated through three-dimensional numerical modelling using ABAQUS. The obtained results showed that the raft significantly suffers from rotation about the vertical axpipelinis and horizontal displacement. Both bending moment and shear forces in piles due to fault rupture exceeded the capacity values of piles. The maximum bending moment and shear forces within piles took place at the connection of piles to the raft and exceeded allowable values when the fault slipped more than 0.3 m.
... The incorporation of the structural elements in the experiment also needs to be simplified for the measurements Li et al., 2019;Yang et al., 2020). Numerical simulations based on continuum analysis (such as the finite element method, FEM) have promise for studying complex mechanical behavior of the fault-soil-structure systems at the engineering scale (Anastasopoulos and Gazetas, 2007b;Agalianos et al., 2019;Baziar et al., 2016;Fadaee et al., 2020). However, the mesh distortion problem still limits the application of traditional FEM analysis for large deformations and the fracture separation of structural elements. ...
The reactivation of the Chelungpu Fault triggered the 1999 Chi-Chi Mw 7.6 earthquake, resulting in substantial ground surface ruptures and severe damage. After the earthquake, the surveys organized by the Central Geology Survey (CGS) of Taiwan and the National Center for Research on Earthquake Engineering (NCREE) immediately investigated a variety of cases related to engineering structures damaged by substantial ground deformation. The investigations gathered valuable in-situ data before human activities disturbed the local setting and altered co-seismic features of interest, providing opportunities for studying the interaction between surface rupture and engineering structures. This study outlines the reconnaissance of damaged engineering structures in Shigang District that cover three typical types of foundations and analyzes the fault geometry and fault slip at the local scale to construct a geomechanical model for numerical simulation. In addition, 3-dimensional (3D) modeling was performed for each case study to investigate the damage mechanisms of the structures subjected to the substantial ground deformations by using PFC3D (Particle Flow Code 3D), which is based on the discrete element method (DEM). The results of the DEM analyses, which have been calibrated with the in-situ data, showed the ability to evaluate the overall ground deformation, the detection of structural movement, and the critical elements of progressive collapse during faulting. This study demonstrates that the 3D DEM simulation is a reliable analysis tool for studying earthquake fault rupture-overburden layer-engineering structure interactions and can produce useful information for hazard assessment with an acceptable computation time. The 3D DEM analysis is therefore suggested to be applied to assess the potential damage scenarios for the engineering structures located in active fault zones.
... The research group of the National Technical University in Greece performed a series of numerical studies on the behaviors of pile foundations subjected to faulting [20][21][22][23]. They found that pile foundations are more vulnerable to fault deformations than shallow foundations owing to smaller diversions of fault ruptures. ...
Both pile foundations and shallow foundations are deemed to be vulnerable to significant fault deformation. However, the pile foundation-shallow foundation interaction in dip-slip fault has never been studied, to the authors' knowledge. This study presents the results of two centrifuge tests, in which a shallow foundation and single piles are subjected to reverse faulting. The tests are compared with the ones from previous studies in the following conditions: free-field, with only a shallow foundation, and with only single piles. The results show that there is a significant interaction between the single piles and shallow foundations. The presence of single piles leads to larger displacements and rotations of shallow foundations. The shallow foundation affects the pile behaviors in two ways: 1) the rupture diversion caused by the shallow foundation leads to different magnitudes and distributions of soil displacements along the piles; 2) the shallow foundation prevents the free deformation of soil, resulting in increasing soil stress even after outcropping.
... Permanent ground displacement due to fault rupture would cause serious damage to tunnels or buried pipelines [1−3]. Although faults in seismically active areas should be avoided if possible, it is inevitable that some infrastructure will cross such areas [4,5]. Especially in recent years, in order to address problems of uneven areal distribution of water resources and inconvenient transportation in western mountainous areas, China has constructed many traffic tunnels, water tunnels, and energy-transmission pipelines, including the Dianzhong Water Diversion Project, the Sichuan-Tibet Railway Project, and the West Route of the South-to-North Water Transfer Project. ...
Active fault creep slip induces deformation of rock mass buried deeply in fault zones that significantly affect the operational safety of long linear projects passing through it. Displacement distribution patterns of rock masses in active fault zones which have been investigated previously are the key design basis for such projects. Therefore, a discrete element numerical model with different fault types, slip time, dip angles, and complex geological features was established, and then the creep slip for normal, reverse, and strike-slip faults were simulated to analyze the displacement distribution in the fault rock mass. A disk rotation test system and the corresponding laboratory test method were developed for simulating rock mass displacement induced by creep slippage of faults. A series of rotation tests for soft-and hard-layered specimens under combined compression and torsional stress were conducted to verify the numerical results and analyze the factors influencing the displacement distribution. An S-shaped displacement distribution independent of fault dip angle was identified corresponding to reverse, normal, and strike-slip faults. The results indicated that the higher the degree of horizontal extrusion, the softer the rock mass at the fault core, and the higher the degree of displacement concentration in the fault core; about 70% of the creep slip displacement occurs within this zone under 100 years of creep slippage.
... Structures supported on rigid mat or box type foundations performed quite well, in contrast to those on isolated footings or piles. Stiff buildings, founded on rigid boxtype foundations, may force fault ruptures to divert (Anastasopoulos and Gazetas 2007a;Anastasopoulos and Gazetas 2007b). Also, observations after the 1999 Chi-Chi earthquake (Kelson et al. 2001) and 1992 Landers earthquake (Murbach et al. 1999) proved that massive and adequately reinforced concrete slab foundations locally influenced the style and location of near-surface deformations. ...
This research introduces a new effective approach, including a weak vertical wall (WVW) and a strong inclined wall (SIW) under a shallow foundation, to reduce the rotations caused by a fault rupture. A series of centrifuge tests, followed by numerical modeling and verified by the test results, were conducted to explore the most suitable characteristics of an inclined wall. It is shown that a WVW is, in some cases, ineffective when it is not in the fault rupture path. Furthermore, uncertainties related to determining the exact location of the fault outcrop make it essential to construct a SIW beneath a foundation to protect the foundation that has already been improved by the WVW. The results proved that the application of the proposed approach could reduce the damage potential to the surface and embedded foundations located at various positions relative to reverse faults with various dip angles.
Permanent ground displacement due to faulting during strong earthquakes threatens stability of civil structures. To protect surface foundations from faulting, several mitigation techniques have been developed. Due to limitations of earlier mitigation strategies for unidentified reverse faulting conditions, this research presents a novel mitigation system, including installing sliders beneath the wings of a V-shaped concrete element, to reduce footing rotation. To evaluate the effectiveness of the suggested mitigation strategy, concrete strength tests, a physical centrifuge test and a comprehensive numerical study for different fault locations and dip angles were conducted for the first time. Results demonstrated that the placement of the sliders beneath the V-shaped wings had a significant effect on dissipating the fault dislocation. Compared to the previous mitigation techniques, the proposed system decreased the foundation rotation from a high value (11 o ) to a low value (3.2 o ) for the worst-case scenarios. Furthermore, the friction coefficients among sliders and concrete, the concrete wing inclination angle, length, and thickness were critical parameters to design the optimum proposed system. On the other hand, soil layer thickness and relative density did not significantly affect the footing rotation.
The earthquake-resistant design of lifelines, such as pipelines, tunnels and bridges, is based on the reliable representation and estimation of the seismic loading. In the case of lifeline–fault crossings, the design fault displacement is typically derived from estimates based on fault dimensions via empirical fault scaling relations for a given “design” scenario event. This approach comes with an unknown level of safety because the fault productivity and the actual distribution of earthquake events are essentially disregarded. To overcome this challenge, a simplified approach is proposed by statistically analyzing the outcome of probabilistic fault displacement hazard analyses (PFDHAs). A selection of faults from the 2020 European Fault-Source Model is used to build the logic tree and to set the range of parameters considered in the PFDHAs. The methodology allows the (mostly conservative) approximation of the fault displacement corresponding to any given return period based on readily available data, namely fault productivity, fault mechanism, fault length, and lifeline crossing location on the fault. The proposed methodology has been proposed and adopted as an informative Annex in prEN 1998-4:2022.
Active faults in the earthquake region are consistently regarded as a potential geological hazard to the construction and operation of railway engineering. However, crossing active faults is always difficult to be avoided for railway construction. In this paper, three-dimensional finite element models are established to study the behaviors of the railway embankment under normal faulting. The constitutive model used in the soil layer is validated by using the data of the centrifuge tests from the existing paper. A series of parametric studies are conducted considering the faulting offset, the thickness of the soil layer, the dip angle of the fault and the cross-fault angle of the embankment. Emphasis is given to (1) the affected zones; (2) the vertical displacement, the longitudinal slope, the lateral displacement, and the radius of the curvature of the embankment centerline; (3) the potential regions where the fault ruptures outcrop based on the plastic strain; (4) the stress characteristic of the embankment surfaces. The analysis shows that the increase of faulting offset would increase the value of longitudinal slope in the cross-fault region of the embankment. The existence of soil layer and its thickening would widen the affected zones and the regions where the fault ruptures outcrops. The fault dip angle and the cross fault angle of the embankment have a complex effect on the behaviors of the crossing embankment. The depth of the subsidence zone of the embankment would increase with the decrease of fault dip angle and the large fault dip angle would change the primary fault rupture to be a compressive one directly above the fault line. If the embankment crosses the fault line obliquely, the curvature radius of the centerline would hardly meet the design code.
Underground structures are inseparable components of public transportation and infrastructure networks that are vulnerable to interaction with fault rupture. To address some of the practical concerns, a series of 3D nonlinear finite element models were conducted and the effects of the tunnel cross-section shape, surcharge loads, and faulting angle on the mechanical response of linings were widely investigated. The geological aspect of the problem was also considered by modeling a fault line in both parallel and perpendicular positions to the tunnel cross-section. Axial forces, bending moments, and rotation of tunnels subjected to reverse faulting in different vertical fault throws were recorded and discussed. The outcomes from the numerical simulations elaborated that developed axial forces in the lining parallel to the fault line may differ by more than 200% by changing the tunnel shape from a circular shape to a horseshoe or square structure. The ratio of forces induced by the faulting to the static loads of lining ranged from 1.5 to 6 times based on the tunnel shape, the rigidity of the tunnel as well as the dimension of the tunnel. It can be inferred from the results that the response of tunnels subjected to fault dislocation depends on various parameters that should be considered by verified numerical simulations to predict precise responses for proposing practical solutions.
Tunnels subjected to reverse faulting are dangerous, experiencing large inner forces and movements. However, there is a lack of effective mitigation measures to protect shield tunnels from reverse faulting. This study proposed a novel mitigation measure, inclined rigid sliding walls, for shallow buried shield tunnels subjected to reverse faulting. Validated numerical modeling is performed to explore the responses of the tunnel, the effects of the walls, and some influence factors. The results show that the walls are effective to protect the shield tunnel from revere faulting. The function of the walls is to release the fault deformation by sliding and develop a relatively stable condition between the walls with less shearing. The walls can decrease the soil pressures, inner forces, and movements of the tunnel. Three possible interaction mechanisms are summarized: hanging wall mechanism, shear mechanism, and footwall mechanism. The walls work best under the footwall mechanism. The detailed protection effects of IRSWs depend on the relative tunnel location, burial depth of the tunnel, the distance between the tunnel and walls, angle of walls, relative depth of walls, and fault dip angle.
A two-dimensional discrete element modeling is adopted to study engineering and fundamental aspects of shear band formation in reverse faulting through sandy soils with varying densities. The employed DEM modeling methodology is verified with the experimental centrifuge result. From an engineering perspective, results show that the shear bands formed due to reverse fault consist of multiple ruptures formed at the different fault raise. These ruptures may deviate toward the hanging or footing wall depending on the faulting angle. The distortion zone outcropping location is captured by the W/H ratio at the 1% normalized fault throw (h/H) step. Various micro and macro aspects of shear banding, such as porosity, coordination number, and strong contact forces within the localized areas along the shear bands, are studied. Moreover, a link is established between the micro and macro events occurring inside the shear bands. The results show that the wedge pressure formed between the shear band and back-thrust rupture in the fault with a dip angle smaller than 45° significantly affects the back-thrust formation and micro-macro parameters in the shearing region.
An approach is developed for estimating the responses of a tunnel with multiple flexible joints under fault movements. Initially, a new simplified mechanical model of flexible joints is built, and a closed-form solution for a tunnel with multiple flexible joints is derived using Green’s function method. Then, the explicit solution of a tunnel with flexible joints subjected to fault movement is subsequently obtained and verified by comparing its results with those from the numerical modeling. Finally, the responses caused by different factors, i.e., fault displacement, lining stiffness, surrounding rock property in the fault zone and joint stiffness, are investigated in detail to provide a better understanding of the mechanical mechanism of flexible joints. The results show the differences in displacement and rotation induced by flexible joints can be quantitatively calculated by the proposed solution in different cases. The flexible joint is capable of reducing the internal forces of the lining and the influence ranges of fault dislocation on tunnel responses. A lower joint stiffness increases the displacement difference monotonically and efficiently reduces the internal forces of the lining. The proposed analytical solution can be used to predict the seismic responses of fault-crossing tunnels with multiple flexible joints under fault movement in engineering design.
Some fault areas respond with stable, quasi-static motion, with slip rates comparable to tectonic rates of millimeters to tens of millimeters per year, inducing deformation development of rock mass in active fault zones. Herein, a mechanical model of fault creep was established considering that the displacement pattern is subject to the static displacement of the fault rupture based on the fault characteristics and geological conditions, and a function of different critical parameters was proposed and evaluated. Displacement distribution patterns were identified by the in situ stress, mechanical parameters of the rock mass in the fault zone, the coefficient friction of contact surfaces between the fault core and damage zone, and fault inclination angle. The higher the horizontal extrusion degree and the softer the rock mass of the fault core are, the higher the degree of displacement concentration in the fault core.
The occurrence of intense earthquakes in cities placed near active faults is unavoidable. The characteristics of these earthquakes are different from those occurring in the sites placed in the far-field. After destructive earthquakes, such as Landers-California (1992), Kobe-Japan (1995), Chi-Chi-Taiwan (1999), Duzce and Kocaeli-Turkey (1999), engineering societies and scientific committees realized that these characteristics should be considered in the analysis and design of structures placed in near-faults. One of the destructive characteristics of near-fault earthquakes that has caused great loss of lives and severe structural damages is surface fault rupture. However, it was observed that some structures survived this phenomenon and the rupture path was changed and passed through the vicinity of structures without severe foundation damages. In most of the standards of seismic design of structures, this characteristic is denied; in some other standards, fault avoidance zones are considered to deal with surface rupture, but these zones are usually inadequate. In this investigation, the effect of foundation stiffness on the surface fault rupture path is studied using numerical studies. The possible effects of soil properties are considered via modeling 2 different soil mediums. Moreover, the mat foundations with different dimensional characteristics are modeled considering soil-foundation interaction. This FE study shows that the foundation stiffness has a significant effect on the rupture path; increasing stiffness of the foundation by increasing the thickness or decreasing the length, affects fault rupture path.
This year marks ten years since the Great East Japan Earthquake in 2011 and the following Fukushima Daiichi nuclear accident. This accident has created a critical need to quantify the seismic response of such critical structures under different levels of seismic hazard. Most seismic-related research studies have been conducted on reinforced concrete walls employed in conventional buildings; however, such walls in nuclear and industrial structures are uniquely designed with very low aspect ratios and relatively large thicknesses. Therefore, several studies have demonstrated that the seismic performance of reinforced concrete walls in nuclear and industrial structures has not been yet adequately quantified to enable robust seismic risk assessment. In this respect, the current study uses a multi-layer shell element in OpenSees to develop a numerical model that can simulate the seismic response of reinforced concrete shear walls with low aspect ratios similar to those used in nuclear and industrial structures. Subsequently, the developed model is validated against the results of several walls tested in previous experimental programs under cyclic loading. The validation results show that the developed model can capture the response of the walls including the initial stiffness, peak load, stiffness degradation, strength deterioration, hysteretic shape, and pinching behaviour at different drift levels.
Constructing structures with the lowest possible use of the material has long been an interesting topic among engineers. In this regard, the resilience of structures in the face of natural hazards and their concomitant effects, such as the resonance phenomenon, should also be taken into account. Frequency-constrained optimization problems seek to not only construct structures with the least possible material amount, but also prevent the resonance phenomenon, enhancing the sustainability of the structures by reducing the total material consumption while minimizing the future damage cost incurred by structural components due to this effect. This article assesses the truss optimization problems with natural frequency constraints using the improved version of the newly developed meta-heuristic algorithm, referred to as the water strider algorithm (WSA). Improved water strider algorithm (IWSA) utilizes two mechanisms to improve the performance of WSA. The first one is the opposition-based learning (OBL) technique, and the other is a mutation method. The OBL technique for the initial population improves the convergence rate and the accuracy of the final result, and the mutation method helps it to approach the global optimum and avoid the local one. Three benchmark spatial truss optimization problems are selected from the literature to examine the efficiency of IWSA in comparison to other well-established algorithms as well as its standard version, WSA. The results reveal the viability and competitiveness of the IWSA algorithm in the framework of design optimization with frequency constraints in comparison to its standard version and other structural optimization algorithms.
Although different kinds of foundations have been investigated against an earthquake faulting, the interaction between pile group and dip-slip fault has not yet been fully understood. This letter investigates the interaction between piled raft and normal faulting by means of centrifuge and numerical modelling. In centrifuge test, a piled raft was simulated with a half model for a better observation of fault rupture path under the raft. The loading transfer mechanism was further examined using a three-dimensional finite difference software (FLAC3D). The measured and computed results showed that the piled raft displaced and tilted linearly with the magnitude of faulting. The fault rupture bifurcated into two and diverted towards both edges of the raft. Two types of loading transfer mechanism were identified during faulting. Working load transferred from the raft to the underneath piles, and also from the piles on the side of the hanging wall to the piles on the footwall side, resulting in compression failure of the piles on the footwall side.
2017 yılı Aralık ayından itibaren KOÜ Harita Mühendisliği Bölümü’nün yürütücülüğü ve Kocaeli Büyükşehir Belediyesi’nin desteği ile “Çok Bandlı InSAR ve GNSS Tekniği ile Doğu Marmara (İzmit Körfezi) Düşey Yönlü Yer Değiştirmelerin İzlenmesi, Zemin Çökmeleri ile Bina Yoğunluğu ve Sıvılaşma İlişkisinin Araştırılması” başlıklı ve 117Y155 numaralı TÜBİTAK projesi kapsamında İzmit körfez bölgesinde risklerin tespiti için çalışmalara başlanmıştır. Bu bağlamda, proje kapsamında yapılan bina yoğunluk analizleri ve sıvılaşmanın körfez bölgesi çevresindeki mekânsal dağılımı CBS ortamında bütünleşik olarak ele alınarak mekânsal dağılımları incelenmiştir. Zemindeki yüke ait bilgi çıkarımı için binaların 3. boyutu dikkate alınarak bina katlarının mekânsal dağılımları mekânsal otokorelasyon çalışmaları ile irdelenmiştir. Mekansal otokorelasyon analizlerinden Lokal Moran’s I istatistikleri dikkate alınmıştır. Ayrıca körfez ve çevresinde görülen sıvılaşma potansiyeli 0-3 m, 3-6 m, 6-9 m, 9-12m’den 33-35 m derinlikleri için oluşturulmuştur. Sıvılaşma potansiyel eşiklerine göre, farklı derinlikler için, sıvılaşma değerleri kategorize edilerek sıvılaşma alanları ve riskli bölgeler tanımlanmıştır. Sonuç olarak sıvılaşma risk alanlarında bulunan bina tespitleri yapılmıştır. Çalışma; ileriye yönelik doğal afetlere karşı sürdürülebilir önlemlerin alınması, yapılaşma hızı ve yoğunluğu için önlem planlarının hazırlanması, Gölcük ve İzmit Körfez çevresinde bina ve zemin sıvılaşmalarının mevcut durumunun belirlenmesi, risk taşıyan alanlarda mühendislik tedbirlerinin alınarak yapı ve can güvenliğinin sağlanması ve afet değerlendirmelerinde altlık oluşturması açısından önem arz etmektedir.
The interaction between an underground tunnel in a sand deposit while a reverse fault rupture propagates from the bedrock to the ground surface was simulated using the discrete-element method (DEM). The propagation pattern of the fault ruptures and the deformation profiles of the soil at the ground surface were analysed in detail considering the effects of the location and rigidity of the tunnel. The DEM simulations were verified against a set of centrifuge laboratory experiments. The DEM simulations were also compared with a set of finite-element numerical models and the efficiency of each method for the simulation of fault rupture–tunnel interaction was assessed for the first time. Both the DEM and the continuum numerical models were found to be effective complementary tools, capable of providing valuable insight into fault–tunnel interaction mechanisms. However, the DEM simulations produced a better correlation with the experimental results.
The reactivation mechanisms of coseismic surface ruptures associated with the 2011 Mw 6.7 Fukushima-ken Hamadori earthquake in Japan are investigated using in-situ controlled hydraulic injections in subsurface boreholes. Two fault segments were selected for reactivation studies, one across a coseismic rupture, the Shionohira site, and one across a non-coseismically ruptured segment, the Minakami-kita site. A series of water injections in sealed sections of boreholes set across the fault progressively bring the fault to rupture by a step-by-step decrease of the effective normal stress clamping the fault. While the fault is rupturing during these hydraulic stimulations, borehole displacements, fluid pressure and injection flowrate are continuously monitored. Then, the tests were analyzed using fully coupled hydromechanical modeling. The model was calibrated on field data, and a parametric study was conducted to examine the modes of fault reactivation. Coseismic surface rupture of the Shionohira fault showed a pure dilatant slip response to hydraulic tests, while the tectonically un-activated Itozawa fault (South) indicated a complex hybrid response to tests related to both a higher frictional and cohesive strengths of the fault. The analysis of the induced Shionohira slip event showed that it is reasonably modeled as a Coulomb rupture with an eventual dependency of friction on slip velocity, in good accordance with laboratory-derived rate-and-state friction data on the Shinohira gouge samples. In contrast, the Itozawa fault reactivation mechanism appears dominated by tensile failure with limited Coulomb shear failure. Thus, the applied protocol proves to be able to isolate significant differences in fault physical properties and rupture mechanisms between two segments of the same fault system, opening perspectives to better assess near-surface rupture effects, and therefore the safety of structures such as dams or nuclear waste repositories subject to large earthquakes.
Earthquake-induced faulting may cause severe damage to adjacent underground structures such as pile foundations and tunnels. A reasonable distance to the free-field fault rupture outcrop is important for the safe design of pile foundations. Identifying the potential damage zone for a tunnel crossing a fault is also crucial. In this paper, three-dimensional centrifuge and numerical modeling of piles and tunnels subjected to normal faulting are reported and discussed. Propagation of fault rupture and induced pile displacements in centrifuge tests were captured and analyzed by the particle image velocimetry technique. The performance of a single pile, a pile group and a tunnel was monitored. A series of three-dimensional numerical back-analyses were performed using a strain-softening Mohr–Coulomb model in FLAC3D. Moreover, a numerical parametric study was conducted to examine the distance from the pile foundation to the free-field fault rupture outcrop. Furthermore, the effects of tunnel depth on the behavior of the tunnel were investigated by comparing two different tunnel depths. New insights from the centrifuge tests and numerical analyses are revealed and three characteristic zones namely safe, transition and translational can be identified.
Earthquakes of large magnitudes cause fault ruptures propagation in soil layers and lead to interactions with subsurface and surface structures. The emergence of fault ruptures on or adjacent to the position of existing tunnels cause significant damage to the tunnels. The objective of this paper is to study the interaction of an embedded tunnel within a soil layer and the soil deformations imposed upon by normal faulting. A centrifuge modeling under 80-g acceleration was conducted to investigate the rupture propagation pattern for different relative tunnel positions. Compared with the free field condition, due to tunnel and normal fault rupture interactions, focused on soil relative density and tunnel rigidity in this research, found that they can dramatically modify the rupture path depending on the tunnel position relative to the fault tip. The tunnel diverts the rupture path to its sides. This study presents the normal fault-tunnel interaction with the tunnel axis parallel to the normal fault line, to examine the changes that take place in fault rupture plane locations, the vertical displacement of the ground surface with tunnel presence and the effect of tunnel rigidity and soil density on fault tunnel interaction.
The tunnel crossing active fault is severely damaged under the action of fault dislocation. Considering the “economic and safety” principle in engineering design, the tunnel damage should be effectively reduced. In this work, a two-level design method for fault dislocation was proposed and the Urumqi subway tunnel in China was chosen as a typical model to deeply investigate its application feasibility. Based on the definition of the design events of different levels and corresponding design goals, three-dimensional finite element soil-tunnel models were established to estimate the response of tunnel. Meanwhile, the rationality of soil-tunnel model was judged by tunnel deformation and internal forces distribution characteristics analysis, and the two-level design goals were evaluated by comparing tunnel damage degree and volumes. The results suggest that under the condition of fault dislocation, the tunnel without disaster mitigation method suffers severely shear, tensile-crack, and compressive damage, which may eventually induce the tunnel collapse. The tunnel damage is reduced significantly by adopting the method of flexible joint. For Urumqi subway tunnel with flexible joints, both of the two-level design goals are effectively realized.
Recent earthquakes have shown that the interaction between faults and structures could cause extensive damage to the surface and underground structures. Field observations showed that the need for design regulations for fault rupture due to fault movement in areas with active faults seems necessary. In this study, the three-dimensional finite element (FE) model in the Abaqus FE program to study the behavior of a 9-story steel structure with a moment-resisting frame system based on three types of mat foundations, pile group, and diaphragm walls was used on sandy soil. The performance of the system of structure-foundation was evaluated taking into account the structural and geotechnical performance goals such as the drift ratio of floor levels, displacement of the foundation, and distribution of bending moment and shear force along with the pile and foundation. In this study, the position of the foundation relative to the fault line and the foundation type were considered as key parameters. The results of the analysis showed that the best performance in reducing the ratio of the permanent drift ratio of the floors related to the structure with the diaphragm wall system. This was in the case that the edge of the foundation is tangent to the fault line, the residual drift ratio reached 1.62%. Also, in most cases, in small amounts of fault sliding, the mat foundation system had a smaller difference than the other considered foundation system in this study.
In the present study, the interaction mechanism of a 10-story moment-resisting building frame sitting on the conventional piled raft foundation with a strike-slip fault rupture with a dip angle of 90̊ is studied via three-dimensional finite element numerical simulation using ABAQUS. In addition, an alternative composite foundation system with geosynthetics reinforced interposed layer between piles and raft is proposed to improve the safety and performance of foundation under strike-slip fault ruptures. The interposed layer is reinforced with two high tensile strength of the geotextile layer. The inelastic behaviour of piles under large ground deformations is simulated using moment-curvature relationships of the real reinforced concrete section of piles and ductility concepts. The performance of both composite and conventional piled raft foundations are evaluated in terms of the geotechnical and structural responses of foundations including rotational and translational displacements and shear forces of the raft, as well as shear forces and ductility capacity of piles. The obtained results show the superior performance of composite foundation with geotextile reinforced interposed layer in terms of a significant reduction in shear forces in the raft and piles, as well as ductility demand in the piles.
Possible use of H/V spectral ratios of microtremors is explored for estimating the effects of subsurface soil conditions on the ground motion characteristics. Theoretical formulas to simulate microtremor H/V spectra are presented assuming that microtremors consist of surface waves. Using these formulas, an inverse analysis of microtremor H/V data is presented for estimating the layer thicknesses of subsurface soils, in case that a priori information of the VS values at the sites is given. Microtremor measurements with only one station are conducted at four sites where down-hole strong motion records are available, and microtremor H/V spectra are determined. The inversion of these spectra successfully results in the S-wave velocity profiles down to the bedrock with VS over 700 m/s. With these profiles, the ground motion characteristics during earthquakes are computed using one-dimensional response analyses. The computed motions show fairly good agreement with the observed ones. This indicates that the proposed microtremor H/V method may be promising for estimating S-wave velocity profiles and local site conditions.
The shapes and locations of failure surfaces in alluvium overlying active dip-slip faults are studied on the basis of experiments performed in a fault test box. A simple model for predicting primary and secondary failure surfaces in the alluvium caused by unidirectional movement on the bedrock fault is reviewed. This model is employed to evaluate additional failure surfaces produced by fault movement in the opposite direction and subsequent to the initial movement. The shapes and locations of these latter failure surfaces are almost unaffected by the presence of failure surfaces caused by the initial fault movement. Ground surface expressions in alluvium associated with movements on dip-slip faults are summarized. Three field cases are reviewed and related to the experimental observations and the proposed simple model. This model is used to predict shapes and locations of failure surfaces in alluvium overlying dip-slip faults. Model predictions compare favorably with observations from the field.
The Chi-Chi earthquake provides dramatic evidence of the damaging effects of surface ground deformation to buildings, lifelines, and other facilities. Much of the building damage is associated with surface faulting and folding along the Chelungpu thrust fault. Our detailed surveying at representative sites along the fault shows that the rupture commonly is a relatively simple 1-to 4-m-high scarp with minor hanging-wall deformation and localized (but severe) uplift, folding, and graben formation along the scarp crest. For individual scarps, the width of defor-mation is about 10 to 20 times the net vertical displacement. Distributed secondary faulting and folding on the hanging wall occurred as much as 350 m from the primary fault. Near the northern end of the rupture, growth of a pre-existing 1-km-wide late Quaternary anticline produced severe ground rupture along multiple thrusts and back-thrusts but only minor tilting between fault strands. The pattern of building damage coincides with the pattern of geologic deformation, with severe damage along large fault scarps and lesser but still significant damage attributable to distributed secondary surface deformation on the hanging wall. Rup-ture-related building damage on the footwall occurred next to the prerupture fault trace, where the hanging wall bulldozed onto the footwall. The width of this damage zone is related to the local horizontal shortening along the fault and generally is less than 10 m. Building zonation along reverse faults should account for this pattern of surface deformation. In addition, buildings with massive foundations locally influ-enced the style and location of near-surface deformation, producing variations in fault strike or accentuated secondary deformation on the hanging wall.
Microtremor measurement using one sensor was conducted at five sites in Golcuk, Turkey, across the damaged area due to the 1999 Kocaeli earthquake, and the horizontal-to-vertical (H/V) spectral ratios of microtremor for the sites were determined. The inverse analyses of the H/V data successfully resulted in the two-dimensional shear wave velocity (V S) profile down to the bedrock. With this profile, ground motions during the main shock were simulated using two-dimensional response analysis, and then strength demands of the ground motions were computed for a simplified building system. The evaluated ground and building responses are consistent with the damage distribution in the area. This indicates that the estimated V S profile and ground motions are reasonable and that the microtremor H/V method is reliable evaluating site effects.
The M w 7.4 Izmit earthquake of 17 August 1999 struck a part of the North Anatolian fault in the area of Izmit Bay (NW Turkey). Historical information shows that the fault which moved during the generation of this earthquake consists of two fault segments moved during the generation of large (M∼7) earthquakes in 1719 and 1754, respect-ively. Since then only the central part (between Izmit and Lake Sapanca) of this fault ruptured by the generation of a smaller shock (M = 6.6) in 1878. The spatial stress variations based on the calculation of changes in the Coulomb Failure Function (CFF) associated with this earthquake are supported by the distribution of strong aftershock foci. Large positive values of CFF to the east and west of the mainshock epicenter are in agreement with the notion that secondary faults were triggered there by the generation of the main event. Large positive values of CFF are also observed in the adjacent western fault segment where the 1766 event was generated, evidencing the occurrence of the next strong earthquake in this segment.
Two devastating earthquakes occurred in Turkey, one on August 17 and the other on November 12, 1999. The magnitudes were 7.4 and 7.2 respectively. The epicenter of the first earthquake was located near Golcuk, a town near Kocaeli province, 110 km from Istanbul. The epicenter of the second earthquake was in Duzce, 150 km from Istanbul. The first earthquake occurred after midnight and killed more than 15000 people. This number is obtained from an official report, while the actual deaths are expected to be more than 20,000. The earthquake was a nightmare for the whole country, and affected almost 10 cities including Istanbul. The second earthquake occurred on November 12 in the early evening, and killed about 1000 people. The affected area from the two earthquakes has a population of about 20 million, which is one third of the whole population of the country, and almost half of the Turkish economical infrastructures is located in this region. This paper gives an overview of the two devastating earthquakes, including geological background of the region, economical impacts and degrees of damages on different aspects.
Tests were performed on dense and loose sand in a glass-walled fault test box to investigate the shapes and locations of failure surfaces that may occur in alluvium overlying active dip-slip faults. The experimental procedure is reviewed and the results of the tests with reverse and with normal movements along the bedrock faults are presented. Based on the experimental results, a simple model is developed to predict the shapes and locations of failure surfaces in the soil. These are determined as a function of the depth of the soil, the angle of dilation for the soil, and the dip angle of the fault. The conditions for development of a graben structure, as observed during normal movement on the bedrock fault, are also determined. The emphasis of the study is on the mechanics of deformation and failure in cohesionless soil above dip-slip faults in relation to principles of soil mechanics. The simple model is also evaluated in relation to real field conditions.
We have conducted a paleoseismic investigation of serial fault rupture at one site along the 110-km rupture of the North Anatolian fault that produced the Mw 7.4 earthquake of 17 August 1999. The benefit of using a recent rupture to compare serial ruptures lies in the fact that the location, magnitude, and slip vector of the most recent event are all very well documented. We wished to determine whether or not the previous few ruptures of the fault were similar to the recent one. We chose a site at a step-over between two major strike-slip traces, where the prin cipal fault is a normal fault. Our two excavations across the 1999 rupture reveal fluvial sands and gravels with two colluvial wedges related to previous earthquakes. Each wedge is about 0.8 m thick. Considering the processes of collapse and subse quent diffusion that are responsible for the formation of a colluvial wedge, we suggest that the two paleoscarps were similar in height to the 1999 scarp. This similarity supports the concept of characteristic slip, at least for this location along the fault. Accelerator mass spectrometry (AMS) radiocarbon dates of 16 charcoal samples are consistent with the interpretation that these two paleoscarps formed during large historical events in 1509 and 1719. If this is correct, the most recent three ruptures at the site have occurred at 210- and 280-year intervals.
The Chelungpu fault, Taiwan, ruptured in a M-w 7.6 earthquake on 21 September 1999, producing a 90-km-long surface rupture. Analysis of core from two holes drilled through the fault zone, combined with geologic mapping and detailed investigation from three outcrops, define the fault geometry and physical properties of the Chelungpu fault in its northern and southern regions. In the northern region the fault dips 45degrees-60degrees east, parallel to bedding in both the hanging wall and footwall, and consists of a narrow (1-20 cm) core of dark gray, sheared clay, gouge. The gouge is located at the base of a 30- to 50-m zone of increased fracture density confined asymmetrically to the hanging wall. Microstructural analysis of the fault gouge indicates the presence of extremely narrow clay zones (50-300 mum thick) that are interpreted as the fault rupture surfaces. Few shear indicators are observed outside of the fault gouge, implying that slip was localized within the gouge zone. Slip localization along a bed-parallel surface resulted in a narrow gouge zone that produced less high-frequency ground motion and larger displacements (average 8 m) during the earthquake than in the southern region. Displacement in the southern region averaged only 2 in, but ground shaking consisted of large amounts of high-frequency ground motion. The fault in the southern region dips 20degrees-30degrees at the surface and consists of a wide (20-70 in thick) zone of sheared, foliated shale with numerous gouge zones. These data demonstrate a potential correlation between fault structure (i.e., gouge width, geometry) and earthquake characteristics such as displacement and ground motion (i.e., acceleration).
The characteristics of earth pressure loads on buried structures due to fault movements are examined and two types of finite element analyses are described which can be used to calculate the magnitudes of these pressures. Although the problem is three-dimensional, the results of two-dimensional analyses are shown to be consistent with the results of model tests. These analyses can be used to determine the distribution of pressures on the structure, and to estimate the magnitudes of the earth pressure loads for design of a structure subject to fault movements.
Discusses the mechanics of earthquake movement, the measurement of earthquake risk, and the engineering problems caused. Permanent displacement can occur on faults, and techniques for recognising active faults are noted. Other damage can result from acceleration and shaking. -K.Clayton
Four Managua, Nicaragua faults, including the one under the 15-floor Banco Central building, experienced surface fault rupture during the December 23, 1972 earthquake. Heavy damage along the fault zones indicated that surface fault displacement contributed to many building failures. The Banco Central building, which is located in Bancos fault zone, survived both strong seismic shaking and surface fault rupture. The 1972 ruptures deviated from the trace of older fault cracks a short distance from the basement of the bank. The fault rupture had been channeled around the reinforced concrete basement through the weaker soils and alluvial material; the strong basement walls were not displaced. The new cracks constitute a zone of weakness that should divert the next differential fault displacements around the basement.
Over the last 20 years our understanding of how active faults move in earthquakes, and our ability to recognise them before they move, has increased dramatically. From a situation in the 1970s when even the most fundamental characteristics of earthquake faults, such as their depth and orientation, were known only crudely, we can now resolve precise details of their shape, position and even slip variation over their surface, without going anywhere near the epicentral region. These advances have come through the combined use of seismology and space-based surveying techniques, particularly GPS and radar interferometry, so that we are now concerned with apparent discrepancies between the results from these various techniques at a level that would have been dismissed as noise just a few years ago. At the same time we have become much better at identifying active earthquake-generating structures before they move, largely through appreciating the signature they produce in the landscape at the surface. This review outlines some of these developments and discusses where they are taking us. Perhaps we will be less embarrassed in the future than we have been in the recent past by large earthquakes that occurred on faults that were unknown or unappreciated at the time, but most of which could have been identified beforehand, given our better understanding of what to look for. We also have a much better idea of how to visualise the deformation of the continents which, after all, is where we live and where earthquakes cause most damage. The continents behave quite unlike the rigid plates in the oceans: they crumple or fragment over huge regions, so that it makes no sense to ask: “what plate is Greece, or Tibet, on?” The challenge has been to work out the overall motions in such places and see how they are achieved by slip on faults in earthquakes. Some of the processes we can see occurring today require the faulting to evolve with time and we are starting to recognise this in the landscape, identifying faults that grow, interact, or even die, becoming inactive. We are progressing beyond the goal of trying to understand how faulting achieves the present-day large-scale motions to the more profound question of how the fault configurations have evolved through time. Many of these developments have direct application in earthquake hazard assessment, in that they help us to identify active geological structures and to anticipate the likely surface deformations that accompany seismic slip on faults at depth.
The 1999 Kocaeli and Düzce earthquakes of Turkey caused loss of many people and severe structural damage to structures. In addition to poor quality construction and inappropriate construction materials, the damage was caused partly by the permanent displacement of the ground due to faulting and partly by the liquefaction and lateral spread of the ground. The aim of this paper is to make an attempt to describe the general features of the surface ruptures and related ground failures and damage to structures, and to discuss several important examples from both earthquakes which may be precursory for the earthquake engineering community to develop seismic codes for structures in active fault zones.
Many important insights are embedded in the detailed observations of surface rupture of the 1906 San Francisco earthquake, during which surface faulting interacted with pipelines, earth embankments, and buildings. Lessons gleaned from the 1906 rupture, combined with parallel and new insights from recent earthquakes, illustrate how various geologic conditions alter the surface expression of faulting and how surface fault rupture interacts with engineered systems. Geologic and engineering procedures can be employed to evaluate the hazards associated with surface faulting and to develop sound designs. Illustrative examples are used to demonstrate how the hazards associated with surface fault rupture can be addressed. Effective design measures include constructing earth fills to partially absorb underlying ground movements; isolating foundations from the underlying ground movements; and designing strong, ductile foundations that can accommodate some deformation without compromising the functionality of the structure.
The Chi-Chi earthquake provides dramatic evidence of the damaging effects of surface ground deformation to buildings, lifelines,
and other facilities. Much of the building damage is associated with surface faulting and folding along the Chelungpu thrust
fault. Our detailed surveying at representative sites along the fault shows that the rupture commonly is a relatively simple
1- to 4-m-high scarp with minor hanging-wall deformation and localized (but severe) uplift, folding, and graben formation
along the scarp crest. For individual scarps, the width of deformation is about 10 to 20 times the net vertical displacement.
Distributed secondary faulting and folding on the hanging wall occurred as much as 350 m from the primary fault. Near the
northern end of the rupture, growth of a pre-existing 1-km-wide late Quaternary anticline produced severe ground rupture along
multiple thrusts and backthrusts but only minor tilting between fault strands.
The pattern of building damage coincides with the pattern of geologic deformation, with severe damage along large fault scarps
and lesser but still significant damage attributable to distributed secondary surface deformation on the hanging wall. Rupture-related
building damage on the footwall occurred next to the prerupture fault trace, where the hanging wall bulldozed onto the footwall.
The width of this damage zone is related to the local horizontal shortening along the fault and generally is less than 10
m. Building zonation along reverse faults should account for this pattern of surface deformation. In addition, buildings with
massive foundations locally influenced the style and location of near-surface deformation, producing variations in fault strike
or accentuated secondary deformation on the hanging wall.
The dynamic analysis of the rocking response was investigated with a finite element discretization using Abaqus. An advanced contact algorithms was used to incorporate for uplifting the foundations. The supporting soil was modeled as a homogeneous halfspace using two dimensional infinite elements. The study suggest that building geometry and rotation was responsible for the different behavior of the Terveler and Yagcioglu buildings. It was observed that the problem with Terveler is a largely co-seismic bearing capacity failure under the rocking and uplifting structure.
An improved understanding of earthquake fault rupture propagation through saturated clay would assist engineers in siting and designing facilities to be constructed in regions where cohesive soils overlie potentially active faults. The results from numerical analyses suggest that the finite-element method can be applied to this class of problem provided that the soil's nonlinear stress-strain behavior is adequately modeled. It was found that the height of the shear rupture zone in the overlying saturated clay soil at a specified base rock fault displacement depends primarily on the soil's failure strain. As the clay's failure strain decreases, the shear rupture zone in the clay overlying the bedrock fault propagates further at a specified base displacement. Other material parameters such as soil shear strength and stiffness also affect the fault rupture process, but not to the extent of failure strain. The orientation of the shear rupture zone through the soil depends largely on the orientation of the underlying bedrock fault plane.
The phenomenon of earthquake fault rupture propagation through soil is quite complex and is not well understood at this time. This paper presents the results of an integrated investigation of this problem. Insights are developed from the examination of surface fault rupture field case histories, laboratory physical model tests, and physical analogies to the earthquake fault rupture process. Field observations and experimental results illustrate the typical patterns of behavior developed in the soil overlying a base rock fault displacement. Evidence suggests that differential movement across the distinct fault rupture dissipates as the fault rupture propagates toward the ground surface through unconsolidated earth materials, and that the characteristics of the soil overlying the bedrock fault strongly influence the observed earthquake fault rupture propagation behavior.
On 17 August 1999, an earthquake of magnitude 7.4 shook northwestern Turkey. Details on the earthquake's characteristics and
effects across northwestern Turkey are provided and are put in the historical context of previous earthquakes in the region.
The earthquake was the seventh in a series of earthquakes migrating westwards along the North Anatolian fault since 1939.
Information on historical earthquakes, modeling and estimates of the slip rate along the fault indicate that the location
and severity of the earthquake should not have come as a surprise.
Recent earthquakes have reminded the profession of the devastating effects of earthquake surface fault rupture on engineered structures and facilities. Insights from these events are discussed with special emphasis on describing how ground movements associated with surface faulting affect structures. Analytical procedures that can be employed to evaluate the hazards associated with surface faulting and to develop reasonable mitigation measures are also discussed. A project in Southern California where these procedures were applied is presented to illustrate the insight gained from sound engineering analysis of the problem. Similar to other forms of ground failure, such as mining subsidence, landslides, and lateral spreading, effective design strategies can be employed to address the hazards associated with surface faulting. These design measures include establishing non-arbitrary setbacks based on fault geometry, fault displacement, and the overlying soil; constructing earth fills, often reinforced with geosynthetics, to partially absorb underlying ground movements; using slip layers to decouple ground movements from foundation elements; and designing strong, ductile foundation elements that can accommodate some level of deformation without compromising the functionality of the structure.
The 1999 Kocaeli and Düzce earthquakes of Turkey caused loss of many people and severe structural damages to structures. In addition to poor quality construction and inappropriate construction materials, the damage was caused partly by the permanent displacement of the ground due to faulting and partly by the liquefaction and lateral spread of the ground. The aim of this paper is to make an attempt to describe the general features of the surface ruptures and related ground failures and damages to structures, and to discuss several important examples from both earthquakes which may be precursory for the earthquake engineering community to develop seismic codes for structures in active fault zones.
The Kocaeli and Duzce earthquakes that occurred in Turkey in 1999 caused extensive damage and loss of life and property. The policies for mitigation and preparedness of the nation were re-evaluated and new initiatives are being taken in order to minimize possible future losses. The condition where the fault rupture passed through residential and industrial zones during the Kocaeli earthquake caused new level of awareness. An educational mitigation project will be discussed, aimed at preparing, training and educating the local government authorities for disasters.
Motivated by the observed (successful and unsuccessful) performance of numerous structures on top of, or immediately next
to a normal fault that ruptured during the Kocaeli 1999 earthquake, this paper: (i) develops a two-step finite element methodology
to study the propagation of a fault rupture through soil and its interplay with the foundation–structure system, denoted hereafter
“Fault Rupture–Soil– Foundation–Structure Interaction” (FR–SFSI), (ii) provides validation of the developed methodology through
successful Class “A” predictions of centrifuge model tests, and (iii) applies the centrifuge-validated methodology to study
one-by-one the Kocaeli case histories of the first paper (Part I). It is shown that the presence of a structure on top of
an outcropping fault may have a significant influence on the rupture path: with heavy structures founded on continuous and
rigid foundations, the fault rupture diverts substantially and may avoid rupturing underneath the structure. The latter undergoes
rigid body rotation, with its foundation sometimes loosing contact with the bearing soil, but in most cases retaining its
structural integrity. In stark contrast, buildings on isolated footings and, perhaps surprisingly, piles exert a smaller diversion
of the rupture which is thus likely to outcrop between the footings or pile caps; the latter may thus undergo devastating
differential displacements. It is shown that structures in the vicinity of faults can be designed to survive significant dislocations.
The “secret” of successful performance lies on the continuity, stiffness, and rigidity of the foundation.
The most significant damage on highway bridges during the recent earthquakes in Turkey (Kocaeli and Duzce earthquakes) and Taiwan (Chi–Chi earthquake) was the result of fault ruptures traversing transportation infrastructure. This phenomenon and its consequences accentuate the need to examine surface rupture hazards and to identify those areas at risk. This understanding can help to develop remedial measures for both structural and geotechnical engineering. For that purpose, damage to highway bridges during the recent events was reviewed. The total collapse of the highway overpass in Arifiye, during the Kocaeli earthquake, was investigated. The major problems under consideration (in Arifiye) were: (i) dislodging of the bridge spans, and consequently, the total separation of the reinforced concrete girders from the piers; and (ii) the stability of a mechanically stabilized earth wall (MSEW) system under extreme loading conditions. The results of the structural and geotechnical investigations presented herein can be taken in consideration to improve transportation infrastructure against surface rupture hazards.
The study of the Anatolian fault zone shows that major earthquake sequences associated with faulting have been occurring in the zone since historical times with periods of quiescence of 150 years. The fault zone is a broad belt of crushed rocks a few kilometres wide rather than a single continuous rupture. Recent surface breaks within the zone consist of large en echelon ruptures with individual uninterrupted linear features that do not exceed a few kilometres. The average displacement of the two sides of the zone since 1939 is about 90 cm. There is some evidence to show that creep is taking place in some parts of the zone, of the order of a few centimetres per year. Preliminary calculations show that the angle of residual shear resistance mobilised on the fault at failure should be very small.
Observed surface breakage due to strike-slip faulting
- C A Lazarte
- J D Bray
Lazarte CA, Bray JD (1995) Observed surface breakage due to strike-slip faulting. Third Int Conference on Recent Advances in Geotechnical Engineering and Soil Dynamics, Vol 2, pp 635-640
Kocaeli, Turkey, Earthquake of August 17
- Tl Youd
- P J Bardet
- Bray
Morphotectonics and Palaeoseismology Along the Fault Traces of İzmit-Sapanca Strike-Slip and Gölcük-Kavaklı Normal Faults: Kocaeli-Turkey 1999 Earthquake
- S Pavlides
- A Chatzipetros
- Z Tutkun
- V Özaksoy
- B Doğan
Small scale structural pattern along the surface rupture traces of the Izmit-Kocaeli (Turkey) 1999 earthquake
- Z Tutkun
- S Pavlides
- B Doğan
Tutkun Z, Pavlides S, Dogan B (2001) Small scale structural pattern along the surface rupture traces
of the Izmit -Kocaeli (Turkey) 1999 earthquake, 4th International Symposium on Eastern
Mediterranean Geology
Ulusay R, Aydan O, Hamada M (2002) The behaviour of structures built on active fault zones: Examples from the recent earthquakes of Turkey. Struct Eng Earthquake Eng JSCE, 19(2):149-167
Report on 1999 Kocaeli and Düzce (Turkey) Earthquakes. Structural control for civil and infrastructure engineering
- Erdik
Seismic movements. In: Ground movements and their effects on struvtures
- N Jackson
N, Jackson, J (1984) Seismic movements. In: Ground movements and their effects on struvtures. Attewell PB, Taylor RK (eds) Surrey University Press, pp 353–380
Field observation and slip distribution of the
- H S Akyüz
- A Barka
- E Altunel
- R Hartleb
- G Sunal
Akyüz HS, Barka A, Altunel E, Hartleb R, Sunal G (2000) Field observation and slip distribution of
the November 12, 1999 Düzce earthquake (M = 7.1), Bolu -Turkey, The 1999 Izmit and Düzce
Earthquakes: preliminary results. Istanbul Technical University, pp 63-70
Morphotectonics and Palaeoseis-mology Along the Fault Traces of ˙ Izmit-Sapanca Strike-Slip and Gölcük-Kavaklı Normal Faults: Kocaeli-Turkey 1999 Earthquake, IX International Symposium on Natural and Human-made Hazards: Disaster Mitigation in the Perspective of the New Millennium Pavlides
- Chatzipetros A Z Tutkun
- V Özaksoy
- ˘ Do
- B S Z Tutkun
- Chatzipetros A V Özaksoy
S, Chatzipetros A, Tutkun Z, Özaksoy V, Do ˘ gan B (2002) Morphotectonics and Palaeoseis-mology Along the Fault Traces of ˙ Izmit-Sapanca Strike-Slip and Gölcük-Kavaklı Normal Faults: Kocaeli-Turkey 1999 Earthquake, IX International Symposium on Natural and Human-made Hazards: Disaster Mitigation in the Perspective of the New Millennium Pavlides S, Tutkun Z, Chatzipetros A, Özaksoy V, Do ˘ gan B (2003), Trenching along the Gölcük 1999 normal fault: evidence for repeated recent seismic activity, International Workshop on the North Anatolian, East Anatolian and Dead Sea Fault Systems: Recent Progress in Tectonics and Paleoseismology, and Field Training Course in Paleoseismology Sahin M, Tari E (2000) The August 17 Kocaeli and the November 12 Duzce earthquakes in Turkey, LETTER. Earth Planets Space 52:753–757
Near fault site effects in Gölcük
- A Ansal
- E Togrol
- A Kurtuluş
- R İyisan
- V Okur
Ansal A, Togrol E, Kurtuluş A,İyisan R, Okur V (2000) Near fault site effects in Gölcük. In: Proceedings of the 3rd Japan-Turkey workshop on earthquake engineering, vol 2. 21-25 February,
Istanbul, pp 251-262
Representative styles of deformation along the Chelungpu fault from the
- Ki
- K-H Kang
- Page
- Wd
- C-T Lee
- Cluff
- Ls
KI, Kang K-H, Page WD, Lee C-T, Cluff LS (2001) Representative styles of deformation along the Chelungpu fault from the 1999 Chi–Chi (
Paleosismic evidence of characteristic slip on the western segment of the North Anatolian fault, Turkey Banco Central de Nicaragua: a case history of a high-rise building that survived surface fault rupture Engineering geol-ogy and soils engineering symposium
- Y K Sieh
- E Altunel
- A Akoglu
- A Barka
- T Dawson
- T Gonzalez
- A Meltzner
- Niccum Mr
- Cluff Ls
- F Chamoro
- Wylie
Y, Sieh K, Altunel E, Akoglu A, Barka A, Dawson T, Gonzalez T, Meltzner A, Rockwell T (2003) Paleosismic evidence of characteristic slip on the western segment of the North Anatolian fault, Turkey. Bull Seismolog Soc Am 93(6):2317–2332 Niccum MR, Cluff LS, Chamoro F, Wylie L (1976) Banco Central de Nicaragua: a case history of a high-rise building that survived surface fault rupture. In: Humphrey CB (ed) Engineering geol-ogy and soils engineering symposium, No. 14, Idaho Transportation Department, Division of Highways, pp 133–144
Living with earthquakes: know your faults Multiple failure surfaces over dip-slip faults Observed surface breakage due to strike-slip faulting
- Lade
- Pv
- Cole
- Jr
- Cummings
J (2001) Living with earthquakes: know your faults. J Earthquake Eng 5(Special Issue 1):5–123 Lade PV, Cole DA Jr, Cummings D (1984) Multiple failure surfaces over dip-slip faults. J Geotech Eng ASCE, 110(5):616–627 Lazarte CA, Bray JD (1995) Observed surface breakage due to strike-slip faulting. Third Int Confer-ence on Recent Advances in Geotechnical Engineering and Soil Dynamics, Vol 2, pp 635–640
Developing Mitigation Measures for the Hazards Associated with Earthquake Surface Fault Rupture. Workshop on Seismic Fault-Induced Failures - Possible Remedies for Damage to Urban Facilities
- J D Bray
Bray JD (2001) Developing Mitigation Measures for the Hazards Associated with Earthquake Surface
Fault Rupture. Workshop on Seismic Fault-Induced Failures -Possible Remedies for Damage to
Urban Facilities. University of Tokyo Press, pp 55-79
Banco Central de Nicaragua: a case history of a high-rise building that survived surface fault rupture
- M R Niccum
- L S Cluff
- F Chamoro
- L Wylie
Niccum MR, Cluff LS, Chamoro F, Wylie L (1976) Banco Central de Nicaragua: a case history of a
high-rise building that survived surface fault rupture. In: Humphrey CB (ed) Engineering geology and soils engineering symposium, No. 14, Idaho Transportation Department, Division of
Highways, pp 133-144
Report on 1999 Kocaeli and Düzce (Turkey) Earthquakes. Structural control for civil and infrastructure engineering Structures in seismic regions Part 5: Foundations, retaining structures, and Geotechnical Aspects Foundations-innovations, observations, design & practice
- M Erdik
Erdik M (2001) Report on 1999 Kocaeli and Düzce (Turkey) Earthquakes. Structural control for civil
and infrastructure engineering. Casciati F (ed.) G. Magonette, World Scientific
Eurocode EC8 (1994) Structures in seismic regions. Part 5: Foundations, retaining structures, and
Geotechnical Aspects. Brussels: Commission of the European Communities
Gazetas G, Apostolou M, Anastasopoulos I (2003) Seismic uplifting of foundations on soft soil,
with examples from Adapazari (Izmit 1999, earthquake). Foundations-innovations, observations,
design & practice. BGA International Conference,Dundee, pp 37–50
The Effects of Tectonic Movements on Stresses and Deformations in Earth Embankments
- J D Bray
Bray JD (1990) The Effects of Tectonic Movements on Stresses and Deformations in Earth
Embankments, Ph.D Dissertation, University of California, Berkeley
Bray JD, Seed RB, Cluff LS, Seed HB (1994a) Earthquake fault rupture propagation through soil. J
Geotech Eng ASCE, 120(3):543–561
Geotechnical evaluation report for the Gölcük Kücük Industrial Project
GEOS (2000) Geotechnical evaluation report for the Gölcük Kücük Industrial Project. August 2000
(in Turkish)
- T L Youd
- J-P Bardet
- J D Bray
Youd TL, Bardet J-P, Bray JD (2000) Kocaeli, Turkey, Earthquake of August 17, 1999 Reconnaissance
Report. Earthquake Spectra Suppl. A to 16:456
Trenching along the Gölcük 1999 normal fault: evidence for repeated recent seismic activity
- S Pavlides
- Z Tutkun
- A Chatzipetros
- V Özaksoy
- B Doğan
Seed HB (1994a) Earthquake fault rupture propagation through soil
- J D Bray
- R B Seed
- L S Cluff
- JD Bray
Ground Failure Damage to Buildings During Earthquakes. Foundation engineering-current principles and practices
- T L Youd