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Simplified Procedure for Evaluating Soil Liquefaction Potential
Abstract
Significant factors affecting the liquefaction (or cyclic mobility) potential of sands during earthquakes are identified, and a simplified procedure for evaluating liquefaction potential which will take these factors into account is presented. Available field data concerning the liquefaction or nonliquefaction behavior of sands during earthquakes is assembled and compared with evaluations of performance using the simplified procedure. It is suggested that even the limited available field data can provide a useful guide to the probable performance of other sand deposits, that the proposed method of presenting the data provides a useful framework for evaluating past experiences of sand liquefaction during earthquakes and that the simplified evaluation procedure provides a reasonably good means for extending previous field observations to new situations. When greater accuracy is justified, the simplified liquefaction evaluation procedure can readily be supplemented by test data on particular soils or by ground response analyses to provide more definitive evaluations.
... The factor of safety against cyclic failure (i.e., liquefaction triggering or cyclic softening), FS cf , is defined as the ratio of cyclic resistance ratio (CRR) and cyclic stress ratio (CSR) within the traditional simplified method framework (Seed and Idriss 1971). In this approach, the loading associated with a given seismic hazard at level ground sites is given by Seed and Idriss (1971) and Youd and Idriss (2001) ...
... The factor of safety against cyclic failure (i.e., liquefaction triggering or cyclic softening), FS cf , is defined as the ratio of cyclic resistance ratio (CRR) and cyclic stress ratio (CSR) within the traditional simplified method framework (Seed and Idriss 1971). In this approach, the loading associated with a given seismic hazard at level ground sites is given by Seed and Idriss (1971) and Youd and Idriss (2001) ...
... In this approach, the ratio of the CSR (i.e., τ cyc =σ 0 v0 ) and the absolute maximum CSR, CSR max is assumed equal to the ratio of acceleration and absolute maximum acceleration or PGA (Green and Terri 2005;Verma et al. 2019). The computation of N eq requires selection of a reference CSR, CSR ref , set equal to 0.65 CSR max (Seed and Idriss 1971;Seed et al. 1975) herein; additionally, any absolute CSR associated with a positive or negative half-cycle less than 0.1 CSR max was neglected, following Boulanger and Idriss (2004) and Verma et al. (2019). Refer to Stuedlein et al. (2023b) for further details. ...
Regression models are presented to estimate the cyclic resistance of transitional silts as an alternative to semi-empirical case history- and stress history and normalized engineering parameters- (SHANSEP-) based models using a database of cyclic laboratory tests on intact specimens. Expressions for the plasticity index-, PI-, dependent semi-logarithmic slope, exponent b, of the curve describing the variation of cyclic resistance ratio, CRR, and number of loading cycles, N, and the variation of number of equivalent loading cycles, Neq, with b are developed for subduction zone earthquakes alongside corresponding magnitude scaling factors for use in cyclic failure assessments (i.e., liquefaction triggering and cyclic softening) within the Simplified Method framework. A PI-, overconsolidation ratio-, OCR-, and shear strain-dependent model for the variation of CRR with N is presented to estimate cyclic resistance as function of cyclic shear strain failure criteria ranging from 1% to 10%. The suite of models can be used together or separately to facilitate assessments of cyclic failure of, or plan cyclic laboratory test programs and/or calibrate constitutive models for transitional silts in the absence of site-specific laboratory tests.
... Several factors influence liquefaction, including mechanical properties of soil layers, groundwater depth, ground shaking strength and duration, distance from earthquake focus, and the ground's seismic attenuation properties (Goh 1994;Xue and Yang 2014). Because of the presence of many variables that can influence liquefaction occurrence in earthquakes, assessing the liquefaction potential has become a highly complicated issue that has sparked the interest of researchers (González Acosta et al. 2023;Oommen et al. 2010;Orense 2005;Rezania et al. 2010;Robertson and Wride 1998;Seed et al. 1983;Seed and Idriss 1971;Shahri et al. 2012;Uyanık 2020;Youd and Idriss 2001). Procedures for predicting the liquefaction induced by an earthquake through in-situ testing, such as the standard penetration test (SPT), cone penetration test (CPT), and shear wave velocity test (Vs), have been extensively investigated during the past few decades (Idriss and Boulanger 2006;Juang et al. 2009Juang et al. , 2012Moss et al. 2006;Robertson and Wride 1998;Seed 1982;Seed and Idriss 1971;Shen et al. 2016;Wang et al. 2023;Yang et al. 2017;Youd and Idriss 2001). ...
... Because of the presence of many variables that can influence liquefaction occurrence in earthquakes, assessing the liquefaction potential has become a highly complicated issue that has sparked the interest of researchers (González Acosta et al. 2023;Oommen et al. 2010;Orense 2005;Rezania et al. 2010;Robertson and Wride 1998;Seed et al. 1983;Seed and Idriss 1971;Shahri et al. 2012;Uyanık 2020;Youd and Idriss 2001). Procedures for predicting the liquefaction induced by an earthquake through in-situ testing, such as the standard penetration test (SPT), cone penetration test (CPT), and shear wave velocity test (Vs), have been extensively investigated during the past few decades (Idriss and Boulanger 2006;Juang et al. 2009Juang et al. , 2012Moss et al. 2006;Robertson and Wride 1998;Seed 1982;Seed and Idriss 1971;Shen et al. 2016;Wang et al. 2023;Yang et al. 2017;Youd and Idriss 2001). The deterministic method employs these three in-situ tests to assess soil liquefaction. ...
... Lastly, we discuss and compare the obtained results with deterministic and probabilistic methods, and it is demonstrated that FCM-LA is more capable of dealing with the vagueness in liquefaction assessment, than the deterministic or probabilistic approaches based on CPT and Vs data. Seed and Idriss (1971) presented a procedure applied in most situations. Since its inception, this method has been revised and improved numerous times. ...
Assessing soil liquefaction potential is a crucial consideration in the seismic design of structures and their seismic stability. The complex nonlinear behavior of the liquefiable soils and the non-deterministic nature of earthquakes make the liquefaction analysis vague. Accordingly, researchers have progressively focused on employing machine learning and mathematical algorithms to address the complexities and uncertainties of evaluating soil liq-uefaction potential. This paper investigates the performance of fuzzy c-means clustering of incomplete data for assessing liquefaction potential based on cone penetration test (CPT) and shear wave velocity (V s) field data. The research was conducted using two approaches: (1) whole data strategy; (2) partial distance strategy. The used database contains 786 CPT and 846 V s records, with specified liquefaction conditions in past earthquake events. We compared the effectiveness and success of this method with traditional deterministic and probabilistic liquefac-tion evaluation approaches. It was found that the fuzzy c-means clustering model had a comparable predictive ability with other methods and would be reliable when assessing the liquefaction possibility.
... Over the past 50 years, researchers have been actively developing approaches to identify sand liquefaction under earthquake loading (Kramer 1996). Multiple procedures have been developed to identify the triggering of liquefaction with combined field and laboratory testing (Cox, Stokoe, and Rathje 2009;Dobry et al. 1982;Green, Mitchell, and Polito 2000;Boulanger and Idriss 2014;Rathje, Chang, and Stokoe 2005;Seed and Idriss 1971). In the last 20 years, cyclic torsional shear (TS) testing has become used in the research of liquefaction because of its advantages in loading with a true stress path and principal stress rotation (Konstadinou and Georgiannou 2013;Koseki, Yoshida, Sato 2005). ...
... As presented in figure 10, γ PP t shows an approximately linear relationship with the number of cycles in log-log space. This behavior is consistent with the relationship between cyclic stress ratio and number of cycles (Seed and Idriss 1971), which also indicates that larger numbers of cycles can generate more excess porewater pressure. Therefore, inspired by the cyclic stress ratio versus number of cycles model, a similar power function is adopted herein, as given by equation (4). ...
... The slight difference between the two curves in figure 13A is likely caused by the different amount of excess pore-water pressure. The effect of relative density on γ PP t and the generation of excess pore-water pressure is consistent with the stress framework, first proposed by Seed and Idriss (1971). In general, denser soils have more resistance to the triggering of excess pore-water pressure. ...
The combined dynamic torsional resonant column and cyclic torsional shear (RCTS) device is employed to study the generation of excess pore-water pressure, especially the threshold shear strain of excess pore-water pressure, γPPt , in an uncemented poorly graded granular soil. Reconstituted specimens of uncemented sand were constructed under water and then tested in the RCTS device using a newly designed base pedestal, with which pore-water pressure is measured at four points systematically located at 0.75 times the radius of the base pedestal. Specimens were tested under different mean effective confining pressures, and all specimens had B-values above 0.95 at the start of testing. During testing, the excess pore-water pressure was measured continuously during 30 cycles of loading at multiple increasing loading levels. The three major factors influencing γPPt that were investigated are as follows: (1) mean effective confining pressure, (2) relative density, and (3) loading frequency. The results are presented in terms of the following: (1) excess pore-water pressure ratio versus shear strain, and (2) thresh- old shear strain versus number of loading cycles. Other related behaviors such as softening during cycling and post-cyclic moduli changes are also discussed.
... This research used a Soil Investigation Report [9] to evaluate the liquefaction potential, carried out for fourteen boreholes with Standard Penetration Test (SPT) data collection spread over the University of Tadulako area, as presented in the Table 1. The potential liquefaction analysis is calculated by the Safety Factor (S.F.) against liquefaction using a simplified procedure by Seed-Idriss [13] and developed using the SPT-based approaches method composed by Idriss and Boulanger, which the value was obtained by comparing the ratio of cyclic resistance (CRR) and the ratio of cyclic stress (CSR) [14]. For further analysis, the S.F. value was used for determining the potential level of liquefaction using the Liquefaction Potential Index (LPI) method composed by Iwasaki et al. [15]. ...
... One method of analyzing the liquefaction potential is by using the Simplified Procedure method by Seed and Idriss [13] and developed using SPT-based liquefaction triggering analysis for a single boring procedure to evaluate the liquefaction potential during earthquakes by Idriss and Boulanger [14] which obtained the Safety Factor (S.F.) value by comparing the ratio of cyclic resistance (CRR) and the ratio of cyclic stress (CSR), as seen in Equation (2) below: ...
... (2) The simplified procedure uses the equation Seed, and Idriss [13] developed to estimate the shear stress caused by cyclic loading. CSR is calculated as Equation (3) below: ...
On September 28, 2018, The Palu-Koro fault triggered an earthquake of M w 7.5. at a depth of 20 km and 72 km northeast of Palu City. As a result, the University of Tadulako suffered significant damage post this earthquake. The Ministry of Public Works and Housing was assigned to reconstruct this location, which was located near the epicentre, and there are alluvium deposits of the Holocene age with loose sand soil and shallow groundwater levels on-site. Based on the Indonesian Seismic Code SNI 1726:2019, it is necessary to propose liquefaction potential and mitigation for building planning. The study aims to calculate the Safety Factor ( S.F .) against liquefaction using a simplified procedure by Seed-Idriss and developed methods by Idriss-Boulanger. The S.F . was used as an input to determine the Liquefaction Potential Index ( LPI ) by Iwasaki et al. The study showed different categories of LPI values. The highest LPI value was found at BH-05, with a very high liquefaction potential. The soil depths susceptible to liquefaction are up to 9 meters. Application of deep foundation penetrating liquefiable soil layer is recommended as the mitigation. It is necessary to conduct further studies on the deep foundation analysis to be applied to this location.
... Evaluating its liquefaction potential in advance can prevent major casualties and economic losses caused by damage. The internationally accepted simplified liquefaction potential evaluation method was proposed by Seed and Idriss [1], which uses the factor of safety (F s ) to quantify the cyclic resistance ratio (CRR) and the cyclic stress ratio (CSR) and is applied to the analysis of field test results, such as cone penetration tests (CPT) and shear wave velocity tests (Vs) [2][3][4][5]. CPT is usually the preferred test for deterministic determination of soil liquefaction, but the test couldn't be carried out under conditions such as gravel sites. ...
... where X represents the optimal hyperparameter set, and H represents the parameter space {x (1) , x (2) , ⋯, x (k) } composed of observed values. An important work of the hyperparameter optimization algorithm is to promote the optimization of EI, that is, the expectation that f(x) will be less than a certain threshold value y * , which can be defined as: ...
... Seed and Idriss [1] proposed an equation to calculate the cyclic stress ratio, which can be expressed as: ...
... Seismic waves can also cause soil liquefaction, which can result in soil particle displacement and instability [99]. When seismic waves interact with soil, they can cause soil particles to move relative to one another, which can cause soil compaction and a reduction in soil permeability [100]. ...
... This requires an understanding of the mechanics of suffusion and the ways in which rainfall and seismic activity can affect soil stability [67,70,86]. In this context, research and analysis of the effects of combined rainfall and seismic activity on suffusion of soil can inform engineering and construction practices and natural hazard planning, helping to minimize potential damage and risk to life and property [100]. ...
... The various numerical and experimental studies [4,8,15,31,39,44,79,[95][96][97][98][99][100][101] that have been conducted in order to understand the mechanisms behind suffusion. It notes that most of these studies have been macroscopic in nature and operate under the assumption that soil movement is a continuous process. ...
This paper employs the systematic literature review (SLR) methodology to investigate the combined effects of seismic vibrations and rainfall on soil suffusion, a process leading to soil instability. Earthquake activity can accelerate soil liquefaction, exacerbating suffusion, while heavy rainfall can increase soil weight, inducing instability. Consequently, the repercussions of seismic activity and rainfall on suffusion may induce further damage and instability to civil infrastructure. The review reveals that the compound impact of rainfall and seismic vibrations can precipitate severe damage and instability, primarily through two mechanisms. First, earthquakes can catalyze soil liquefaction, inciting soil movement and amplifying the suffusion process. Second, heavy rainfall can saturate the soil, augmenting its weight and rendering it unstable, thereby inducing suffusion. However, the review also reveals a significant gap in understanding and mitigating suffusion triggered by simultaneous rainfall and seismic activity. Current techniques for identifying and mitigating such suffusion are inadequate, highlighting the need for further research. This review posits that the interaction of rainfall and seismic vibrations as a catalyst for soil suffusion demands additional scrutiny. It provides a comprehensive understanding of suffusion and the impact of rainfall and seismic vibrations on suffusive soils, serving as a basis for future studies on this important issue.
... From a structural viewpoint, liquefaction potential of a ground can be assessed regarding physical characteristics of the subsurface structure determined based on two innovative geophysical approaches, including Rayleigh surface waves and electrical resistivities [9]. In addition, the stress-based approach and strain energy-based method are two common experimental procedures in the literature [10][11][12][13][14][15][16]. Among these methods, stress-based method has been more common among researchers for liquefaction assessment [10,17]. ...
... In addition, the stress-based approach and strain energy-based method are two common experimental procedures in the literature [10][11][12][13][14][15][16]. Among these methods, stress-based method has been more common among researchers for liquefaction assessment [10,17]. In this procedure, the shear stress level, mean effective stress, and the number of cycles, are the critical parameters in estimating the liquefaction potential of cohesion-less soils. ...
Mining Exploration, excavation, and construction are considered as mining activities which are recently growing dramatically. Therefore, utilizing the mining wastes with the least environmental damage is a significant concern. Tailings dams are one of the conventional solutions that store the extracted hazardous substances safely for water resources management and environmental protection. This reseach deals with the effects of monotonic and seismic loadings on silt-sized copper wastes existed in a tailings dam at Northwest Iran as a case study. Various values of initial static shear stress are performed using an automated cyclic triaxial system. Monotonic undrained compressive tests were performed with a relatively constant density and considering three values of 50, 100, and 150 kPa for mean effective stress. Depending on the first density of samples, applying a mean effective confining pressure of 100 kPa, increased the initial densities by 25% to 30% as compared to the initial condition.Moreover, the effect of initial shear stress ratio with three values of 0, 0.2, and 0.4 was evaluated. No peak point was observed for samples under α = 0, whereas, samples with α = 0.4 encountered a peak point before reaching to the phase transformation point. The results of cyclic experiments were used to evaluate capacity energy and residual pore pressure based on the strain energy approach. Cyclic tests on the samples were performed considering the shear amplitude of 0.75% and frequency of 0.3 Hz. It is shown that the most energy dissipation occurs at the first cycle possessing the highest stiffness. For α = 0, energy density increased from 474 J/m 3 to 1147.4 J/m 3 , however, a more intense increase was measured from 682 J/m 3 to 5839 J/m 3 when α = 0.4. It is also found that applying initial shear stress has a pretty considerable influence on monotonic strength and the liquefaction resistance of silts. The increase of α from 0 to 0.4 yielded a linear increase in the shear strength of samples in the range of 20 kPa to 70 kPa. The results of this paper were then validated accurately through some previous studies.
... As an approximation of the irregular motion triggered by seismic loading, the amplitude of cyclic sinusoidal deviatoric axial stress was taken to be 65% of the maximum magnitude of shear stress caused by the actual seismic accelerations, as proposed by Seed and Idriss (1971). The amplitude of cyclic deviatoric axial stress d can be computed as follows: ...
... where is unit weight of the soil; H is the depth; a max and g are the peak of the seismic acceleration and the acceleration of gravity, respectively; d is the stress reduction coefficient. Through laboratory tests and field investigations, Seed and Idriss (1971) proposed the variation relationship of d with soil depth. According to the recommended values, the values of d are 0.97 and 0.91 at the depth of 5 m and 10 m, respectively. ...
The Donghekou landslide triggered by the 2008 Wenchuan earthquake was a typical large-scale rapid and long runout landslide. The saturated deposit material in runout path was liquefiable under the dynamic loading, which may play a key role in the hypermobility of the Donghekou landslide. The dynamic loading triaxial compression tests were performed to investigate dynamic responses of the soil samples from the runout path. The influence of variation of pore water pressure of deposit in runout path on the movement process of the landslide was investigated and analyzed by discontinuous deformation analysis (DDA). The results show that the impact loading could cause a sharp rise of the pore water pressure of the soil, but it cannot trigger liquefaction before the sample failure. Seismic loading is the main loading that causes the liquefaction of deposit material, while landquake loading has little effect on soil liquefaction. During the earthquake, liquefaction of the shallow soil (the depth was < 10 m) of deposit in the runout path was induced by the seismic loading. Thus, the shallow runout-path material and landslide debris can slide faster and farther under a significantly small friction.
... Idriss and Boulanger [17] developed the SPT-based liquefaction triggering procedure to analyze the liquefaction potential quantitatively. This procedure is a development and improvement of the previous method, namely the simplified method by Seed-Idriss [18] and the Youd-Idriss method (NCEER) [19]. In this procedure, the safety factor (SF) empirically expresses the liquefaction potential, which can be calculated using equation (1). ...
... Liquefaction had the potential to occur if the SF value was < 1. CSR can be interpreted as the shear stress ratio in the soil caused by an earthquake. CSR was determined using the equation developed by Seed-Idriss [18] in equations (2) to (5) below. ...
On September 28, 2018, at 18:02 local time, a strong tectonic earthquake with a moment magnitude of 7.5 struck Central Sulawesi Province, Indonesia, triggering liquefaction disasters in Palu city and Sigi district. The project of the Anutapura Medical Centre (AMC) building at the Anutapura General Hospital in Palu city is one of the Indonesian government programs to support the rehabilitation and reconstruction of infrastructure after the earthquake. This hospital is located close to the liquefaction-affected area in Balaroa. Geologically, the hospital area is also located in the formation of Holocene deposits that have not been fully lithified. This study aims to analyze the liquefaction potential, which focuses on the construction area of the AMC building. The soil grain size distribution was used for the preliminary analysis of potentially liquified soils. The SPT-based liquefaction triggering procedure was used to calculate the safety factor (SF) against liquefaction. Subsequently, the SF value was further analyzed using the liquefaction severity index (LSI) to determine the severity level. The results show that soils in the study area have the potential to liquefy with a low to moderate severity level. The results are expected to be used as consideration to mitigate the possible liquefaction.
... Typically, a peak ground velocity (PGV) threshold level above 30 cm/s is chosen as one criterion (Baker, 2007 in uences the performance of structures. By contrast, even though studies on soil liquefaction assessment have been developed for several decades since the pioneer work by Seed and Idriss (1971), relatively minimal attention has been given to the effects of NF pulse-like ground motion on-site liquefaction. Soil liquefaction occurs primarily in loose, saturated granular soils, where the pore water pressure increases substantially during cyclic loading, causing a reduction in effective stress between the soil particles. ...
... Two sets of comparable ground motion (NF motion and GL motion) are selected based on PGA and duration (Du). In conventional liquefaction triggering analysis, PGA represents the seismic demand and is associated with cyclic stress ratio, whereas duration that is a function of magnitude represents the number of cycles of cyclic stresses (Seed and Idriss, 1971). To standardize the seismic demand as N c =15, MSF is typically used (Idriss, 1999). ...
Near-fault (NF) pulse-like ground motions have a significant impact on the performance of structures, but their effects on soil liquefaction potential have been relatively understudied. This paper uses 1D effective stress site response analysis capable of modeling porewater pressure (PWP) generation to investigate the seismic site response under NF and general ground motions. The aim is to assess the effects of NF motions on soil liquefaction by considering different soil models and PWP generation models. The results show that NF ground motions generally induce larger ground responses in terms of PWP generation, especially when the durations of the motions are short. This is due to the higher cumulative absolute velocity associated with NF ground motions compared with general ground motions due to a high-velocity pulse under the same peak ground acceleration. However, this effect diminishes as the duration of motion increases. To avoid underestimating seismic demand, especially for small to moderate earthquakes, a preliminary magnitude scale factor modified for the NF effect is suggested for use in conventional soil liquefaction triggering analysis.
... Multiple global studies on liquefaction susceptibility have shown that fine-grained and poorly-grained soils, such as silty, sandy, and gravelly soils, are more susceptible to liquefaction. The same is reflected in past studies by several researchers (Seed and Idriss 1971;Seed et al. 1985;Youd and Perkins 1987;Yoshimi et al. 1989;Guo and Prakash 2000;Yilmaz and Bagci 2006;Muley et al. 2015;Dash and Sitharam 2016;Yazdi and Moss 2016;Rasouli et al. 2020 andGreen et al. 2022). ...
... In the past few decades, three methods have been used to investigate the liquefaction potential of regional soils: stress-based, strain-based, and energy-based. Seed and Idriss (1971) compared undrained cycle strength to seismically generated shear stress using a stress-based technique. Inherent to this procedure is the quantification of the seismic demand imposed on the soil expressed in terms of cyclic shear stress. ...
Liquefaction of soil is a phenomenon where effective stresses get reduced due to the generation of excess pore-water pressures during earthquake shaking. This is manifested by loss of soil stiffness and shear strength. It is a general practice to evaluate the liquefaction potential using EPP generation and single or double amplitude shear strain of 3% or 5%, respectively, using either a stress-based or strain-based approach. The energy-based approach is also preferred by a few researchers, which quantifies the capacity of soil in terms of dissipated energy during an earthquake. In the present investigation, a series of strain-controlled cyclic triaxial experiments are conducted on Solani sand to explore the potential for liquefaction utilizing an energy-based approach. Estimations were performed for varied parameters, including effective confining pressure, strain amplitude, diameter, relative density, and frequency, at appropriate intervals. A relationship is proposed between the dissipated energy per unit volume and the controlling parameters that influence soil liquefaction potential. The experimental investigations are not directly applicable to the field conditions. To overcome these lacunae, a numerical approach is proposed to simulate the experiments, validated, and utilized to simulate the field conditions. For this purpose, a set of six near-field and six far-field ground motions corresponding to the targeted designed spectrum are selected, and the energy experienced on soil samples during these earthquakes is evaluated. Besides, the implication of variation between the energy dissipated by the tested soil to get liquefied and the energy imparted to the on-site soil during earthquake shaking is also discussed.
... Refs. [1][2][3][4][5][6][7][8][9][10]). These procedures are based on geotechnical and geophysical in-situ tests, such as Standard Penetration Test (SPT), Cone Penetration Test (CPT), Flat Dilatometer Test (DMT), Chinese Dynamic Cone Penetration Test (DPT) and shear wave velocity measurements (V S ). ...
... The summary of the geotechnical and geophysical characterization is reported in Fig. 4. The reconstructed stratigraphic column is composed by a thin silty-clayey nonliquefiable crust in the upper 3.5 m depth, namely CL for USCS classification, with FC > 65% and PI ≈ 18-22%, followed by a non-plastic thick sandy and silty-sandy layer with considerable values of FC ≈ 25-35% (SM-SP). According to the liquefaction assessment presented by Amoroso et al. [11] using the "simplified method" [1], the 2012 liquefied deposits can be detected into the upper layer of Po River silty sands (depth approximately between 3.5 and 12 m), characterized by lower values of resistance and stiffness. However, as highlighted already by the authors, the fines content correction applied to the CPT procedure using a "blind" FC estimate or a laboratory-calibrated FC relationship provides high differences into the susceptibility evaluation, resulting important to provide a site-specific FC estimate for the 2012 Emilia epicentral area. ...
... For actual earthquake excitations with irregular acceleration amplitudes, the number of load cycles is conventionally related to the magnitude of the earthquake or duration of strong shaking (e.g. Seed and Idriss (1971); Idriss (1999)) and a magnitude scaling factor used to convert the reference liquefaction resistance to different numbers of equivalent uniform cycles. In this paper, liquefaction strength refers to the CRR at 20 load cycles (CRR @Nc=20 ), following the definition adopted by Ishihara (1993) and used in similar studies investigating links between effects of partial saturation on liquefaction resistance expressed through V p . ...
The liquefaction resistance of partially saturated soil was experimentally investigated for one clean sand and one silty sand collected from a site in Christchurch, in an area severely affected by liquefaction in the 2010-2011 Canterbury earthquakes. A series of cyclic undrained tests were performed on fully and partially saturated sand and silty sand specimens, in conjunction with evaluation of saturation conditions in situ based on comprehensive field measurements of P-wave velocity (V p) in Christchurch deposits. The Skempton's B-value and P-wave velocity were comparatively used as measures for partial saturation in the laboratory. B-value-V p relationships from the test results indicate that V p steadily increases with the B-value until a threshold B-value is reached beyond which V p remains unchanged at values indicating full saturation, i.e. V p ! 1600 m/s. In general, the liquefaction resistance of tested sand and silty sand increases with a decrease in the B-value or V p , i.e. with a reduction in the degree of saturation. Furthermore, test results suggest existence of threshold B-values and V p for tested soils beyond which no significant increase in the liquefaction resistance was observed. This threshold B-values and V p were found to be dependent on soil type and applied confining stress. The effects of partial saturation on liquefaction strength are different for the sand and silty sand when using V p as a measure for the degree of saturation. While a gradual rate of increase in liquefaction strength with decreasing V p is observed for the tested sand, the liquefaction strength of silty sand shows similar gradual increase with a decrease in V p up to about 800 m/s, which is then followed by an abrupt increase in the liquefaction strength for V p < 800 m/s. Generally good agreement between liquefaction strength of tested soils and published data was observed, with a clear distinctive feature in the behaviour of the silty sand as compared to clean sands.
... Die granulometrischen Eigenschaften (Korngrößenverteilung, Kornform und -rauigkeit) sind wichtige, aber nicht die einzigen Einflussfaktoren. Die Rolle der bezogenen Lagerungsdichte und der Bodenstruktur (Aufbau des Korngerüsts) für die Bodenverflüssigung ist unumstritten [4,7,10,[16][17][18][19][20][21][22][23][24][25][26][27][28]. Mit ...
Der Aufbau des Porenwasserdrucks (PWD) während einer Scherbeanspruchung bei behinderter Drainage findet besonders ausgeprägt in lockeren, gesättigten, grobkörnigen Böden statt und führt zur Verringerung der effektiven Spannungen und der Bodensteifigkeit. Unter Berücksichtigung einer vergleichbaren Bodenstruktur (Korngerüst) und unter gleichen Versuchsbedingungen (Spannungsniveau, Wegamplitude usw.) wird das Verhalten verschiedener Böden bei einer gleichen äußeren Belastung unterschiedlich sein. Hierzu wird ein vereinfachter zyklischer Scherversuch (PWD‐Tester) vorgestellt, der einen Vergleich der Neigung zum Aufbau des PWDs gegenüber der Variation von Anfangsdichten für verschiedene Sande ermöglicht. Der Versuch setzt sich aus einem Probeneinbau, einer Konsolidation und einer anschließenden zyklischen Scherung der Probe bei undrainierten Bedingungen innerhalb kurzer Zeit (ca. 30 Minuten) zusammen. Das Ziel dieses Verfahrens ist es, jedem getesteten Sand einen Indexwert zuzuordnen und somit die Neigung verschiedener Sande zum PWD‐Aufbau bis zur Bodenverflüssigung unter behinderter Drainage in Abhängigkeit der Einbaudichte zu quantifizieren.
... OCTOBER 24 TH TO 26 TH , 2023 OURO Preto, Minas Gerais, Brasil 2 based on empirical methods such as the "cyclic stress approach" (Seed & Idriss, 1970) and simplified methods as the Limit Equilibrium Method (LEM) analysis. However, as indicated by (Cudmani et al. 2003), the cyclic stress approach cannot capture the complex behavior of liquefiable soils under dynamic loading. ...
Modelling the seismic response of tailing dams is particularly challenging due to the complex behavior of the involved material and interacting system components, i.e., the dam, the foundation, and the stored slimes. Due to their versatility for the solution of complex boundary-value problems, numerical analysis, particularly the finite element and finite difference method (FEM and FDM), in combination with advanced constitutive models, are being increasingly applied in practice to assess the stability and safety of Tailing Storage Facilities (TSF). This contribution proposes different benchmark tests to validate constitutive models that intend to capture the response of tailing dam materials under seismic loading. Exemplarily, the proposed benchmarks are simulated with a hypoplastic constitutive model. The validation includes a plausibility assessment and a comparison of the numerical results with experimental data from laminar shake box tests and actual seismic records from a well-documented site during strong earthquakes. The imperious necessity for a comprehensive validation of constitutive models to detect and improve model weaknesses and ensure numerical robustness before they are applied to predict the seismic response of tailing dams is demonstrated.
... A similar assessment is valid for the liquefaction phenomenon. Sand-type soils are susceptible to liquefaction [32]. However, parameters such as fine-grained percentages, the plasticity behavior of fines, and the grading shape of coarse material affect liquefaction potential [33][34][35][36][37]. Therefore, each type of sand does not liquefy. ...
Classification systems are crucial to the description and classification of soils, helping to facilitate soil identification, as well as the understanding, and interpretation of soil materials worldwide. In this study, EN ISO 14688-2:2018 and ASTM D2487-17e1 were employed to develop a practical soil identification approach called Practical Group Symbol and Group Name Approach (PSNA). The method presented herein is not a classification system or a standard but is rather an approach that makes EN ISO 14688-2:2018 usable in practice and enables soil particle identification in detail. The use of this practical method can eliminate any ambiguity in communicating soil characteristics. Practical flow charts were prepared for defining group names and symbols of soil particles. The method enables the classification of gravel, sand, silt, clay, and organic material. A user-friendly macro was also developed in Microsoft Excel, utilizing the integrated programming language Visual Basic for Applications (VBA) to facilitate the implementation of this approach. In the present study, an Excel-based triangular diagram was developed. In addition to the triangular diagram, two charts were considered. From these contributions, the group symbol and group name of soil mixtures can be easily and practically defined.
... The simplified stress-based approach [2], is a frequently used technique for determining the liquefaction potential in practical applications. This technique comprises two key components: seismic loading, quantified as cyclic stress ratio (CSR), and cyclic resistance ratio (CRR ), which represents the soil's resistance. ...
The relative density and effective stress of the soil influence the cyclic stress or liquefaction behaviour of granular soil significantly. The state parameter (ѱ) which accounts for relative density and effective stress is utilised in this work to quantify soil liquefaction probability of failure (PL) using the First order second moment (FOSM) method. It is observed that the state parameter-based cyclic resistance ratio (CRR) model used to analyse PL is a complex function of cone penetration test (CPT) parameters since ѱ itself is based on empirical relations which include several derived parameters and other factors, like the coefficient of earth pressure at rest (K0) and soil compression parameters. In order to overcome this complexity in liquefaction probability evaluation, three Machine learning (ML) models, namely Simple Recurrent Neural Network (Simple RNN), Convolutional Neural Network (CNN) and, Deep Neural Network (DNN) are developed and recommended according to their performance in predicting PL. To evaluate the effectiveness of these models, nine statistical performance parameters are calculated. In order to find the model with the highest performance, additional plots such as regression plots, Taylor’s diagrams, error matrix, rank analysis, and regression error characteristic curves are presented. The present study shows that the three ML models based on state parameter perform well in predicting PL. Among these ML models, the CNN model demonstrates highest performance. The findings of this work will aid in expanding the application of state parameter-based ML models and offer risk evaluations for geotechnical engineering design.
... The most widely used methods to evaluate liquefaction triggering are based on the simplified stress-based procedure developed by Seed and Idriss (1971). This method compares the cyclic stress induced in a soil layer by an earthquake with the cyclic strength of the soil to provide a factor of safety against liquefaction. ...
This article develops a framework for and explores the use of case-based reasoning (CBR) to predict seismically induced liquefaction manifestation. CBR is an artificial intelligence process that solves new problems using the known answers to similar past problems. CBR sorts a database of case histories based on their similarity to a design case and predicts the outcome of the design case as the observed outcome of the most similar case history or majority outcome of the most similar case histories. Two databases of liquefaction case histories are used to develop and validate numerous CBR models. Different input parameters and aspects of the CBR method and their influence on the predictive capability of the models are evaluated. Some of the developed CBR models were shown to have a better predictive power than currently existing models. However, more research is needed to refine these models before they can be used in practice. Nevertheless, this study shows the potential of CBR as a method to estimate liquefaction manifestation and suggests several avenues of future research.
... gibi parametreler arasında birçok korelasyon literatürde tanımlanmıştır [27][28][29]. Ayrıca, sığ veya derin temellere sahip üst yapı tasarımında ve binaların sismik davranışında önemli değişkenler olan zemin taşıma gücü kapasitesi, sıvılaşma ve oturma analizleri, yatak katsayısı hesaplamaları ile deformasyon modülleri gibi geoteknik kavramların belirlenmesinde arazi ölçümlerine bağlı elde edilen düzeltilmiş Standart Penetrasyon Deneyi darbe sayısı (SPT-N) kullanılmaktadır [30][31][32][33]. ...
Coğrafi konum olarak Batı Karadeniz Bölgesi’nde bulunan Bartın ilinde geçmiş yıllarda gerçekleşen deprem, sel, heyelan gibi afetlerden dolayı, bölge sosyal ve ekonomik anlamda hissedilir düzeyde etkilenmiştir. Tektonik olarak aktif bir bölge olan Batı Karadeniz Havzasının iklim koşulları, bitki örtüsü ve topoğrafik yapısı nedeniyle yaşanan bu tür afetlerin gelecekte alüvyal tabanlı Bartın ilini sıklık ve şiddet anlamında daha fazla etkilemesi muhtemeldir. Bu sebeple bölgede yapılacak mühendislik yapılarının sismik tasarım sürecinde ve şiddetli yağışlara bağlı meydana gelen su baskınlarının olumsuz etkilerini azaltmak için yapılacak çalışmalarda, elverişsiz zemin koşullarının iyi bilinmesi gerekir. Yapılan bu çalışmada Bartın şehir merkezi ve Amasra ilçesinde bulunan yoğun yerleşim alanlarındaki genel zemin yapısı, geoteknik deprem mühendisliği açısından önemli olan bazı dinamik parametreler kullanılarak analiz edilmiştir. Pilot inceleme alanlarında yapılmış zemin etüt raporlarından elde edilen verilerin analiz edildiği bu araştırmada, geoteknik açıdan problemli ve/veya yapı açısından daha duyarlı yerleşim sahalarının risk değerlendirmesi yapılmıştır. Ayrıca, bölgede en son gerçekleşen Haziran 2022 sel afeti sonrası oluşan bazı taşkın ve heyelan olayları, arazi koşullarında edinilen güncel resimler ve izlenimlere bağlı olarak yorumlanmıştır. Çalışma kapsamında sunulan sonuç ve önerilerin, bölgede inşa edilecek mühendislik yapılarını tasarlayan mühendislerin yanı sıra bölgenin afet durumunu analiz eden araştırmacılara ve yerleşim noktalarının belirlenmesinde görev alan şehir planlayıcılarına yol gösterici olacağı değerlendirilmiştir.
... Furthermore, permafrost degradation may increase the seismic liquefaction potential of soils [59]. During an earthquake, the contraction of saturated granular soil particles transfers stress from particle-particle contacts to pore water, leading to increased pore water pressure and a corresponding reduction in the strength of the material [63,64]. Liquefaction occurs when the pore water pressure rises to a critical level and the behavior of the material changes from solid-like to liquid-like [65,66]. ...
Alaska is one of the most seismically active regions of the world. Coincidentally, the state has also experienced dramatic impacts of climate change as it is warming at twice the rate of the rest of the United States. Through mechanisms such as permafrost thaw, water table fluctuation, and melting of sea ice and glaciers, climatic-driven changes to the natural and built-environment influence the seismic response of infrastructure systems. This paper discusses the challenges and needs posed by earthquake hazards and climate change to Alaska’s infrastructure and built environment, drawing on the contributions of researchers and decision-makers in interviews and a workshop. It outlines policy, mitigation, and adaptation areas meriting further attention to improve the seismic resilience of Alaska’s built environment from the perspectives of engineering and complementary coupled human-environmental systems.
... Site amplification A(f) can be estimated by seismic amplification in shallow media that can be determined using a V S30 model . We calculate A(f) using a 1D equivalent linear method (Seed and Idriss, 1971;Schnabel, 1972). The diminu- ...
A series of moderate-size (Mw 4.0–6.0) earthquakes occurred in South Korea after the 2011 Mw 9.0 Tohoku–Oki megathrust earthquake, incurring public concern about possible occurrence of devastating earthquakes in Seoul—the capital city of South Korea, where historical seismic damage was reported. The seismicity is distributed in Seoul, being dominated by strike-slip earthquakes. The fault planes are oriented in north-northeast–south-southwest, which is a favorable direction to respond to the ambient stress field. Higher rates of seismicity are observed in the northwestern Seoul at depths of <10 km. Micro-to-small earthquakes occur episodically in the central Seoul along the Chugaryeong fault system that traverses Seoul in north–south. Seismic, geophysical, and geological properties illuminate the fault structures. Stochastic modeling of ground motions reproduces the seismic damages of historical earthquakes reasonably, supporting the occurrence of devastating historical earthquakes in Seoul. The seismicity distribution, focal mechanism solutions, geological features, and seismic and geophysical properties suggest the possible presence of earthquake-spawning blind faults in Seoul. The peak ground motions are assessed for moderate-size scenario earthquakes (Mw 5.4 with focal depth of 7 km) at six representative subregions in Seoul. The upper bounds of peak ground accelerations reach ∼11 m/s2. The seismic damage potentials for moderate-size earthquakes are high in most areas of Seoul, particularly around river sides covered by alluvium.
... Comparison between the induced cyclic shear stress and soils' resistance in stress-based approach or evaluation of the pore water pressure ratio in strain based approach. Seed and Idriss, (1971) proposed a simplified procedure for predicting liquefaction potential of a soil deposit subjected to a ground motion. The cyclic shear stress developed at a depth of interest in the soil due to earthquake shaking is approximated by the following expression: ...
... where FS is the safety factor, is the cyclic stress ratio, and is the cyclic resistance ratio. CSR was developed by Seed and Idriss (1970) ...
In Mei 2006, an earthquake occurred, and liquefaction was induced in Bantul Regency in the form of lateral spreading and sand boiling. Based on Indonesia’s liquefaction susceptibility zone map 2019, the Bantul coast was identified as a high liquefaction hazard zone. There is a high risk of liquefaction in that location, and if liquefaction occurs, the effective stresses of the soil will be lost. This study aimed to determine ground motion-induced liquefaction potential in Opak river estuary in Bantul. The peak ground acceleration can be predicted by probabilistic seismic hazard analysis (PSHA) based on Indonesian spectra design application, deterministic seismic hazard analysis (DSHA) based on the mechanism of a recent earthquake in Bantul, and non-linear earthquake site response analysis (NERA) based on the 2004 Parkfield California earthquake, the 1986 Chalfant Valley California earthquake, and the 1987 Superstition Hill California earthquake. The value of acceleration from site-specific responses with DSHA and NERA is 0.558 g. Then, the maximum acceleration, seismic magnitude, N-SPT bore log soil, and other soil parameters are analyzed with a semi-empirical simplified method to estimate the safety factor of liquefaction potential using Settle3. The liquefaction safety factor was calculated by dividing the cyclic resistance ratio by the cyclic stress ratio; liquefaction occurs if the safety factor is less than 1. The result indicates that the Opak river estuary has a liquefaction potential beneath the surface from -1.5 to -16.5 m depth with various thick each boreholes. It implies that the bearing capacity design of the foundation system in this area and the liquefaction effect that will emerge when an earthquake occurs must be appropriately considered.
... During an earthquake, liquefaction occurs in saturated cohesionless soil that loses its strength in response to strong ground shaking. Seed (1970) showed that some significant factors that influence liquefaction potential depend on the soil type and the intensity of ground shaking [7]. ...
The Solo-Yogyakarta-NYIA Kulon Progo is a National Strategic Project to accelerate the accessibility to New Yogyakarta International Airport (NYIA). This toll road will pass through Central Java Province and the Special Region of Yogyakarta Province. Previous studies have investigated that during the 2006 Yogyakarta Earthquake with a moment magnitude, M w of 6.3, liquefaction was found in some areas in Klaten Regency of Central Java Province. This study aims to determine liquefaction potential in the Solo-Yogyakarta-NYIA Kulon Progo Toll Road Section 1, focusing on stations 16+700 to 22+500, which were located in Klaten Regency. This study first analyzes soil conditions and groundwater depth based on soil investigation data. Analysis of liquefaction potential was found out using Idriss-Boulanger based on Standard Penetration. Parameter of peak ground acceleration using two approaches; probabilistic and deterministic. For probabilistic, the peak ground acceleration using probability of 7% in 75 years and 2% in 50 years. For deterministic using the attenuation function of Campbell and Bozorgnia (2014). Then, the Liquefaction Potential Index was also used to determine the level of liquefaction vulnerability in the study area. The results of liquefaction potential analysis using each approach of peak ground acceleration show the differences in safety factor of liquefaction values. It can be concluded that several sites along the study area have the potential to liquefy at a very low to a very high level, with PGA value at least 0,43 for probability of 2% in 50 years, 0,32 for probability of 7% in 75 years, and 0,36 for deterministic approaches sourced by Opak Fault. Then, the location with the highest liquefaction potential is at stationing 20+550, with LPI values of each approach of 42.91, 33.36, and 34.70.
... Maximum earthquake acceleration, earth acceleration, total ground stress, effective ground stress, and also depth factor reduction can be factors that affect the magnitude of CSR. The value of CSR has been formulated by Seed and Idriss [10] which was later developed by Idriss and Boulanger [9] with the equation: ...
Parangtritis Village located in Bantul Regency, Special Region of Yogyakarta. Previous studies showed that the Opak Active Fault line passes right through the east side of the construction. This study aims to examine the potential for liquefaction in the retaining wall and embankment structures in Parangtritis Village in the event of an earthquake in the area. The subsurface evaluation was based on N-SPT drilling data as well as soil data at 4 drill point. The bedrock acceleration value was determined based on SNI 2833:2016. To obtain a more specific bedrock peak acceleration value, the Indonesian Spectra Design seismic data was used by the Directorate General of Highway, Ministry of Public Works and Housing, where the PGA bedrock acceleration value is 0.558 g. The stages of liquefaction potential analysis are divided into three stages, Cyclic Stress Ratio, Cyclic Resistance Ratio, Factor of Safety. Liquefaction Potential Index analysis as a determinant of potential damage. Data processing results at four drill points indicate that the soil layer at several depths has liquefaction potential with a safety factor value of <1. The results of these calculations show that the LPI value is in the LPI vulnerable > 15, indicating a high liquefaction potential.
... a1-a6 are profiles in long period sites, b1-b7 are profiles in moderate period sites, c1-c6 are profiles in short period sites, and d1-d5 are profiles in sites with no peaks. procedure involves empirical stress-based calculations where the liquefaction resistance of soil is compared to a triggering mechanism acting on the soil to induce liquefaction (Seed and Idriss 1971;Youd and Perkins 1978;Youd et al. 2001). However, in this paper, we followed Maeda et al. (2015) in estimating liquefaction resistance for SDS test data based on the 'Specifications for Highway Bridges' of Japan Road Association (JRA) (Japan Road Association 1996). ...
... Seismological Research Letters each soil boring using the simplified procedure of Seed and Idriss (1971) and the Youd and Idriss (2001) relationship of determining the cyclic resistance ratio based on standard penetration test (SPT) data. Available soil boring logs that included soil classifications based on the Unified Soil Classification System (USCS) and SPT or blow count (SPT-N) values were obtained from the Memphis District of the U.S. Army Corps of Engineers (USACE), Tennessee Department of Transportation (TDOT), Tennessee Department of Economic and Community Development, Construction Materials Laboratory, Inc., and Joel B. Spaulding and Company, Inc. ...
Cite this article as Cramer, C. H., A five-year seismic and liquefaction hazard mapping project for five western Tennessee counties began in 2017 and supported natural hazard mitigation efforts in Lake, Dyer, Lauderdale, Tipton, and Madison counties. Additional geological, geotechnical, and geo-physical information has been gathered in all five counties to improve the base northern Mississippi Embayment hazard maps of Dhar and Cramer (2017). Information gathered includes additional geological and geotechnical subsurface exploration logs, water table level data collection, new measurements of shallow shear-wave velocity (V S) profiles, and the compilation of existing V S profiles in and around the counties. Improvements have been made in the 3D geological model, water table model, the geotechnical lique-faction probability curves, and the V S correlation with lithology model for these counties. The resulting updated soil response amplification distributions on a 0.5 km grid were combined with the 2014 U.S. Geological Survey seismic hazard model (Petersen et al., 2014) earthquake sources and attenuation models to add the effect of local geology for Lake, Dyer, Lauderdale, Tipton, and Madison Counties. The resulting products are similar to the Memphis and Shelby County urban seismic hazard maps recently updated by Cramer, Dhar, and Arellano (2018). Generally, the effect of local geology is to reduce seismic hazard at short periods and increase it at long periods. Liquefaction hazard is high only in the alluvial lowlands, but not in the loess covered uplands.
... During the second round of the evaluation, the region's boundaries will serve as a difficult obstacle. Since Seed and Idriss first proposed the simplified method of analyzing soil liquefaction using relative density and SPT-N values as parameters [3] it has been updated and modified several times without affecting the fundamental equations [4,5]. These updates and modifications have been made since Seed and Idriss' original proposal. ...
In this paper, post-liquefaction Standard penetration test (SPT) data was collected from the Chi-Chi earthquake and Deep Belief Network (DBN) model using a metaheuristic-based shark smell optimizer (SSO) to improve the predicted accuracy by many iterations. First, the data were normalized and the correlation between variables was determined using chi-square. Next, random sampling was used to select the parameters that were used to train and test the DBN models. Lastly, the SSO was implemented to improve the model’s accuracy; it was found that SSO not only improved the model’s fitting/accuracy but also sped up the process.
... Different approaches have been proposed to evaluate soil liquefaction potential. Among these, the shear stress or the earthquake peak ground acceleration (PGA) 26 forms the theoretical basis for the widely used "simplified procedure for evaluating soil liquefaction potential" [49][50][51] . Other approaches emphasize the shear strain 14 or the seismic energy 15,[52][53][54] in identifying liquefaction triggering thresholds. ...
Earthquake-induced soil-liquefaction is a devastating phenomenon associated with loss of soil rigidity due to seismic shaking, resulting in catastrophic liquid-like soil deformation. Traditionally, liquefaction is viewed as an effectively undrained process. However, since undrained liquefaction only initiates under high energy density, most earthquake liquefaction events remain unexplained, since they initiate far from the earthquake epicenter, under low energy density. Here we show that liquefaction can occur under drained conditions at remarkably low seismic-energy density, offering a general explanation for earthquake far-field liquefaction. Drained conditions promote interstitial fluid flow across the soil during earthquakes, leading to excess pore pressure gradients and loss of soil strength. Drained liquefaction is triggered rapidly and controlled by a propagating compaction front, whose velocity depends on the seismic-energy injection rate. Our findings highlight the importance of considering soil liquefaction under a spectrum of drainage conditions, with critical implications for liquefaction potential assessments and hazards.
RESUMEN: La ocurrencia de licuación en arenas es muy frecuente en distintas partes del mundo, por lo que existen suficiente cantidad
de datos y estudios para permitir el desarrollo de métodos empíricos relativamente confiables para la predicción del fenómeno. Pero el
fenómeno de licuación no solo ocurre en los suelos arenosos. La experiencia ha demostrado que se puede observar licuación en suelos
gravosos y gravas arenosas, si los depósitos se encuentran lo suficientemente sueltos para que el material tenga un comportamiento
contractivo frente a solicitaciones cíclicas y/o grandes deformaciones o se impide el drenaje como, por ejemplo, en el caso de estratos
finos intercalados. En este artículo se presentan algunos casos históricos de licuación de suelos gravosos a nivel mundial. Se resumen
las causas principales de ocurrencia del fenómeno y también se comentan las limitaciones de los métodos empíricos actuales,
desarrollados para evaluar el potencial de licuación en arenas, al momento de estudiar suelos gravosos. A modo de antecedentes, se
muestran algunos ejemplos de cómo la licuación de la fundación afectó a presas de materiales sueltos durante el terremoto de Bhuj, en
India, en al año 2001. Finalmente, se presenta el caso de la Presa Punta Negra, construida sobre el Río San Juan (2010 a 2016), en la
provincia homónima, en la que debió adoptarse un criterio conservador para el aluvión de la fundación a causa de la incertidumbre
respecto del potencial de licuación de los suelos gravosos, por la inexistencia de métodos suficientemente validados para evaluar el
fenómeno.
ABSTRACT: Liquefaction of sands is very common all around the world, thus there are enough amount of data and studies to
develop empiric methods that are relatively reliable to predict the phenomenon. But liquefaction is not limited exclusively to sands,
Experience has shown that liquefaction can occur in gravels and sandy gravels if the deposits are loose enough for the material to
have a contractive behavior against cyclic loading and/or large deformations, or if drainage is restricted as, for example, in the case
of interspersed thin layers of fines. In this article the authors present a few historical cases of gravelly soil liquefaction worldwide.
The main causes for gravel liquefaction to occur are summarized and the limitations of the existing empirical methods to assess
liquefaction (originally developed for sands) are summarized as well. Finally, the study case of Punta Negra Dam is presented. The
dam was built on San Juan river, in the homonym province, and a highly conservative criterium was adopted for the alluvial soil on
the foundation due to the uncertainties regarding the liquefaction potential of gravels, given the lack of sufficiently validated methods
to assess liquefaction phenomenon.
A typical ground investigation for characterizing geotechnical properties of soil requires sampling soils to test in a laboratory. Laboratory X-ray computed tomography (CT) has been used to non-destructively observe soils and characterize their properties using image processing, numerical analysis, or three-dimensional (3D) printing techniques based on scanned images; however, if it becomes possible to scan the soils in the ground, it may enable the characterization without sampling them. In this study, an in-situ X-ray CT scanning system comprising a drilling machine with an integrated CT scanner was developed. A model test was conducted on gravel soil to verify if the equipment can drill and scan the soil underground. Moreover, image processing was performed on acquired 3D CT images to verify the image quality; the particle morphology (particle size and shape characteristics) was compared with the results obtained for projected particles captured in a two-dimensional (2D) manner by a digital camera. The equipment successfully drilled to a target depth of 800 mm, and the soil was scanned at depths of 700, 750, and 800 mm. Image processing results showed a reasonable agreement between the 3D and 2D particle morphology images, and confirmed the feasibility of the in-situ X-ray CT scanning system.
In the world, cyclic triaxial tests are widely used to evaluate the liquefaction potential of soil and determine the cyclic parameters for seismic design. However, the application of cyclic trixial test for evaluation of soil liquefaction is still limited in Vietnam. This paper introduced the cyclic triaxial apparatus, method and testing procedure to access the liquefaction potential of sand under cyclic loading. The research on some saturated sandy soils with high fine-grained content in Vietnam showed that the research results of soil liquefaction potential is reliable. In which, the liquefaction characteristics of sand are evaluated based on the changes of stress, strain and pore water pressure according to the cyclic cycles, thereby determining the liquefaction point and liquefaction boundary for fine sandy soils at different density levels.
Prambanan temple complex is geologically located above an active fault that stretches from the area of Prambanan, Piyungan, Pleret, Imogiri, and Pundong. This fault is often called the Opak fault. The re-active fault triggered by a magnitude 6.3 earthquake activity that rocked Yogyakarta on May 27, 2006. An earthquake is a natural disaster that can destroy soil structure in its path. One of damage to soil structure caused by the earthquake is liquefaction. This study aims to determine whether the condition of the subgrade foundation Prambanan secure against the threat of liquefaction.This study uses a simplified procedure for estimating the liquefaction potential. Simplified procedure uses a comparison of two variables include seismic force in the soil layer called the cyclic stress ratio and capacity to withstand soil liquefaction is cyclic resistance ratio. The data used are N-SPT is in the court of Prambanan. Data recorded earthquakes that have occurred in Yogyakarta used is a version of USGS years 1957-2016.The results of this study indicate that the value of Factor of Safety (FS)> 1.2 with the existing condition of ground water at a depth of -12.0 meters. It can be concluded that security conditions subgrade foundation Prambanan safe against liquefaction potential.Keywords: Prambanan, liquefaction, Simplified Procedure.ABSTRAKKompleks Candi Prambanan secara geologis berada di atas sesar aktif yang membentang dari wilayah Prambanan, Piyungan, Pleret, Imogiri, dan Pundong. Sesar ini sering disebut dengan patahan Opak. Sesar tersebut kembali aktif karena dipicu oleh aktivitas gempa bumi 6,3 SR yang mengguncang Yogyakarta pada 27 Mei 2006. Gempa bumi merupakan bencana alam yang dapat merusak struktur tanah yang dilaluinya. Salah satu kerusakan pada struktur tanah yang ditimbulkan oleh gempa bumi adalah likuifaksi. Penelitian ini bertujuan untuk mengetahui apakah kondisi tanah dasar fondasi Candi Prambanan aman terhadap ancaman likuifaksi.Penelitian ini menggunakan simplified procedure untuk mengestimasi potensi likuifaksi. Simplified procedure menggunakan perbandingan dua variabel antara gaya seismik pada lapisan tanah yang disebut dengan cyclic stress ratio dan kapasitas tanah dalam menahan likuifaksi yaitu cyclic resistance ratio. Data yang digunakan adalah N-SPT yaitu di pelataran Candi Prambanan. Data gempa tercatat yang pernah terjadi di Yogyakarta digunakan adalah versi USGS tahun 1957 – 2016.Hasil penelitian ini menunjukkan bahwa nilai Factor of Safety (FS) > 1,2 dengan kondisi eksisting muka air tanah pada kedalaman -12,0 meter. Hal ini dapat disimpulkan bahwa kondisi ketahanan tanah dasar fondasi Candi Prambanan aman terhadap potensi likuifaksi.Kata Kunci : Candi Prambanan, Likuifaksi, Simplified Procedure
This study examines the potential of soft computing techniques, such as multi-adaptive regression spline (MARS), Bayesian regularization neural network (BRNN), Levenberg–Marquardt neural network (LMNN) vis a vis statistical regression technique, like multiple linear regression (MLR)-based classification approaches to evaluate liquefaction potential of soil in terms of liquefaction index (LI) from a large database consisting of post liquefaction SPT measurements and liquefaction field observations. The liquefaction classification accuracy: 94.44% (LMNN) and 94.44% (MARS) of the developed LI models is found to be better than that of available artificial neural network (LMNN) model (88.37%), support vector machine model (94.19%) and multi-gene genetic programming (MGGP) model (94.19%) on the basis of the testing data. A ranking system is used to evaluate the above models based on different statistical performance criteria like correlation coefficient (R), Nash–Sutcliff coefficient of efficiency (E), log normal probability distribution of ratio of predicted LI (LIp) to observed LI (LIm) etc. Based on the above ranking criteria LMNN model is found to be better than BRNN, MGGP, MARS and MLR models. Model equations based on the above techniques are also presented for geotechnical engineering professionals.
The liquefaction potentials of coastal sands in the Lagos metropolis was investigated in this study using geotechnical and geophysical methods. The study aims to reveal the possible causes of failures in engineering structures around the coastal areas. To achieve this objective, the Seismic Multichannel Analysis of Surface Waves, Cone Penetrometer Test and Standard Penetration Test were used to carry out measurements of soils parameters at three different sites, which were used to characterize the geological units in the areas. The results of the MASW measurements showed that the shear waves velocity (V s ) ranges from 160 and 470 m/s. The very loose to loose sand delineated had Vs in the range from 170–250 m/s. The tip resistance and sleeve resistance values spanned between 4.0–72.0 kg/cm ² and 6.0–94 kg/cm ² respectively. The depth of the liquefiable sands in the study area varied between 2.5 to 18.0 m. At Ikoyi, owing to the prevalence of loose silty sand, corroborated by borehole data and the LPI index, it is classified as having a high-risk liquefaction and could be responsible for the tremendous damages on structural infrastructures. The sediments mapped at Okun-Ajah and Badore sites were mainly saturated loose sand with high likelihood to liquefaction. Hence, the severity was classified as very-high to high risk. The study concludes that the presence of these sediments and other factors that could induce ground motion making the study sites potentially susceptible to liquefaction. Hence, an urgent attention must be given to early monitoring measures to address the trend.
North Sulawesi Province was locating in a tectonically active area, affected by subduction of the Sulawesi Sea plate, Sangihe, and Halmahera. These plates are still active to provide an earthquake threat. Several large earthquakes that came from various plates around Manado City have been recorded. A large earthquake that shakes sandy soil can produce liquefaction events. The Malalayang beach area, located in the West of Manado City a part of Malalayang Beach Area Arrangement Work Package and the Bunaken Village Ecotourism Arrangement, was chosen as the research object to analyse the possibility of liquefaction. The research begin with collect boring testing data, lab test data, and earthquake data such as the moment of magnitude and Peak Ground Acceleration (PGA). This study also uses various methods or attenuation equations to determine the peak ground acceleration from the history of earthquakes obtained from multiple sources. Based on the data obtained from the field and laboratory tests, data processing is carried out to determine the liquefaction potential. From the results of the Liquefaction Potential Index (LPI) calculation, it was found that the Malalayang Beach Area has the potential for the occurrence of the liquefaction phenomenon.
Morocco, which is in a seismically active zone, is currently experiencing a significant development in terms of the realization of development and infrastructure projects. Therefore, reflection on soil liquefaction problems during project design is essential. The densification of soils by vibro compaction is a recent process of soil treatment, its effect is to improve the geo mechanical characteristics of the soil in this case the relative density and subsequently the reduction of the potential for liquefaction, it is a technique soil improvement in the mass, it is closely linked to the grain size of the soil to be treated, its percentage of fines less than 10% (going to 0.08 mm <10%), this technique gives the treated soil sufficient cohesion to avoid large increases in pore pressures during the earthquake. This article aims, through the study of a real case, to evaluate the effectiveness of vibro compaction to improve the relative density of the soil and consequently the reduction of the risk of liquefaction of the treated soil. The work focuses on the analysis of the SPT tests carried out before treatment and on the CPT tests of control of the vibro-compactge works carried out after execution. This study showed that this process generates an effect of improvement of the relative density and reduction of the compaction by inducing a reduction of the risk of liquefaction
Paleo-liquefaction features of sand dykes and sand blows were identified in the 1990s at multiple host sediments in the Fraser River delta in southern British Columbia all younger than 3500 BP. These paleo-liquefaction sites could be linked to Cascadia subduction earthquakes. Empirical magnitude-bound relationships are often used to estimate paleo-earthquake magnitudes. To determine the lower bound magnitude of Cascadia interface earthquakes that could have generated the paleo-liquefaction features, we use ground motion prediction equations for interface earthquakes from the sixth Canadian seismic hazard model of the 2020 National Building Code of Canada. We estimate the minimum M and its peak ground acceleration ( a max ) of an interface earthquake required to initiate paleo-liquefaction in the study region. Starting with three full-rupture deterministic scenarios of varying source-to-site distance, we determine the minimum M required from Cascadia subduction zone interface mega-thrust earthquakes to induce liquefaction in the Fraser River delta spans 8.0–8.9 with a corresponding a max range of 0.09–0.13 g. We also perform a back-calculation paleo-liquefaction analysis in a probabilistic framework to incorporate aleatory uncertainties (cone penetration resistance, groundwater table, and a max ) and epistemic uncertainties (liquefaction simplified model) via the Monte Carlo simulation. The developed probabilistic methodology is also applicable to a forward liquefaction assessment and other liquefaction sites globally. The median M from this probabilistic paleo-liquefaction for the four investigated sites lies between 8.8 and 9.0. Our probabilistic results also reveal that Cascadia interface earthquakes with M > 8.9 lead to a 31%–57% probability of liquefaction triggering in the Fraser River delta. In addition, we developed deterministic and probabilistic magnitude-bound curves specific to Cascadia interface earthquakes and representative site class E conditions. These curves provide more accurate magnitude estimations for predicting seismic-induced liquefaction from Cascadia interface earthquakes for sites in the Pacific Northwest than empirical bound curves.
Bu çalışma kapsamında, İzmir ili Bornova ilçesinde bulunan bir inşaat alanında dinamik zemin davranışı analizleri ve sıvılaşma analizleri gerçekleştirilmiştir. Bu amaç doğrultusunda, öncelikle sahada uygulanan sondajlar ve jeofizik yöntemlerin verileri bir veri bankasında toplanmıştır. Sahanın 3 boyutlu modeli çıkartılmış ve sondajların konumlarına göre sahanın farklı açılardan geoteknik profilleri elde edilmiştir. Sonrasında dinamik zemin davranışı analizleri, frekans tanım alanında bir boyutlu eşdeğer doğrusal analiz yöntemiyle DEEPSOIL programı kullanılarak yapılmıştır. Analizlerde 1977 İzmir, 1992 Doğanbey, 1995 Dinar ve 1999 Kocaeli depremlerine ait ivme-zaman kayıtları kullanılmıştır. Ayrıca, SPT-N değerleriyle sıvılaşma analizleri yapılarak alanın sıvılaşma riski belirlenmiştir. Alan içinde farklı deprem etkileri sonucu 0.4g ve üzeri değerlerde en büyük yatay yüzey ivmelerinin oluşabileceği, sıvılaşma riskinin alan genelinde mevcut olmadığı, ancak lokal olarak sıvılaşma gözlenebileceği sonucuna ulaşılmıştır.
Magnitude MW6.4 Petrinja earthquake on 29 December 2020, caused liquefaction in the fields, under some houses, under some bridges, damages to some roads and bridges, several levees, some landslides and rockfalls, and wide opening of sinkholes. Several levees along the Kupa and Sava rivers were damaged – mostly longitudinal cracks were noticed near or on the body of those levees, often followed by sandy soil ejected to the surface – on these locations some layers of soil containing sand were discovered on the depth of 5 to 8 m, which obviously liquefied during the earthquake – causing strong movements of the levee body, cracking and lateral spreading. Designs of the solutions are shown with changes made due to the very unfavourable weather conditions in long and heavy periods of rain. Design of a soil improvement is shown for a bridge which suffered settlelments due to liquefaction of the foundation soil. An example of successful foundation is shown – of a reservoir on a soil improved by gravel columns – which helped the pore pressure dissipation after the earthquake. The paper gives some information on other investigation and other remediation works.
The most important method of understanding liquefaction-induced engineering failures comes from the investigation and analysis of earthquake damage. In May 2021, the Maduo Ms7.4 earthquake occurred on the Tibetan Plateau of China. The most representative engineering disaster caused by this earthquake was bridge damage on liquefied sites. In this study, the mutual relationships between the anti-liquefaction pre-design situation, the ground motion intensity, the site liquefaction severity, and the bridge damage state for this earthquake were systematically analyzed for typical bridge damage on the liquefied sites. Using field survey data and the current Chinese industry code, simulations of the liquefaction scenarios at typical bridge sites were performed for the pre-design seismic ground motion before the earthquake and the seismic ground motion during the earthquake. By combining these results with post-earthquake investigation results, the reason for the serious bridge damage resulting from this earthquake is revealed, and the necessary conditions for avoiding serious seismic damage to bridges built in liquefiable sites is presented.
On 12 January 2010, the M7.0 Haiti earthquake caused infrastructure damage induced by extensive soil liquefaction and foundation failure in the Port-au-Prince International Seaport and Léogâne Plain. This study re-examines the soil liquefaction effects of the main shock and aftershock events by exploring the existing studies on calcareous sands, reviewing the phenomenon of liquefaction in the Caribbean Islands, and associating them within the seismic history of the Greater and Lesser Antilles. Due to the geomorphology of the Islands, urban development has typically been concentrated along the coast, in locations vulnerable to soil liquefaction. This study demonstrates that the liquefaction that occurred at sites in the M7.0 Haiti event was triggered by the main shock even at low peak ground accelerations (PGAs), the first aftershock effects were significant, and soil liquefaction was not rare in the Antilles. It identifies the elements that characterize historical cases of soil liquefaction caused by earthquakes in the Caribbean Islands. In addition, it points out the characteristics and findings of paleoliquefaction and paleoseismicity investigations conducted in the Caribbean region. Investigations and studies on the calcareous sand liquefaction and paleoseismology are essential to improve the seismic hazard and risk assessment of the Caribbean Islands. The existence of a large number of studies making reference to this topic highlights its significance.
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