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Soil liquefaction during earthquakes
... The first step is to assess whether liquefaction is triggered by the seismic hazard being analyzed, and the second step is to assess post-cyclic deformations resulting from the loss of stiffness and strength due to liquefaction. Liquefaction triggering in level or sloping ground (i.e. with static shear stresses) is typically assessed using the cyclic stress approach (Seed and Idriss, 1971;Whitman, 1971;Idriss and Boulanger, 2008) and yield strength ratios methods, su(yield)/ 'vo (Olson and Stark, 2003). These semi-empirical methods for assessing the triggering of liquefaction are of limited use when assessing seismically induced deformations. ...
... Figure 3 shows the cyclic resistance ratio from a single amplitude 3% criteria for triggering liquefaction of the SM tailings for a range of initial conditions (state parameters and consolidation stresses). Consistent with previous research on sands used to develop semiempirical liquefaction correlations (Idriss and Boulanger, 2008), increasing confining pressure decreases the cyclic resistance although at a somewhat slower rate than the semi-empirical approach. It is anticipated that the actual reduction of cyclic resistances under confining pressure is controlled by the relative change of the consolidated void ratios and critical state void ratios (Montgomery et al., 2012). ...
... A 3% single amplitude or 5% double amplitude strain is typically used to define triggering of liquefaction (Idriss and Boulanger, 2008). Other recent studies have shown that a residual excess pore water pressure ratio (ru) of 0.8 captures the onset of liquefaction indicated by a sudden increase of cyclic strain accumulation (i.e. ...
Seismically induced deformations and pore water pressure generation potential in tailings storage facilities (TSF) are typically assessed by evaluating undrained cyclic direct simple shear (CDSS) laboratory testing on relatively undisturbed or reconstituted specimens. In this study, the potential for pore pressure generation and cyclic shear deformation accumulation from post-liquefaction triggering is evaluated based on our internal database of two sites of undrained monotonic direct simple shear (DSS), CDSS, and undrained and drained monotonic triaxial testing on silty sand tailings and based on published data from testing of natural sands performed by others. The effects of initial state parameter (: Been and Jefferies 1985) and shear compressibility (: slope of the critical state line) on cyclic shear deformations, pore pressure generation, post-liquefaction strength and stiffness are assessed. The results highlight that tailings pore pressure generation and cyclic resistances at triggering of liquefaction can generally be described by the initial state parameter, while post-cyclic shear straining and strengths are best described by the ratio of the initial state parameter to shear compressibility (/). This work illustrates the importance of using a state-based framework to assess reasonable ranges of cyclic-induced deformations and pore water pressure generation in sandy tailings, which are consistent with field state parameter-based estimates.
... The liquefaction hazard is a phenomenon triggered by an earthquake [15], shallow groundwater depth [16], and loose sand and silt grains [17]. The effects of liquefaction are sand boiling [11] [18] [19], lateral spreading, ground oscillation [20], loss of soil bearing capacity [20] [21], ground settlement [18] [21] [22], flow liquefaction and cyclic mobility [11] [23]. The effects of the liquefaction need to be taken into account because liquefaction can have many effects on the soil, especially if buildings are standing on it that will collapse, causing soil liquefaction-induced ground settlement [18] [21] [22]. ...
... The effects of liquefaction are sand boiling [11] [18] [19], lateral spreading, ground oscillation [20], loss of soil bearing capacity [20] [21], ground settlement [18] [21] [22], flow liquefaction and cyclic mobility [11] [23]. The effects of the liquefaction need to be taken into account because liquefaction can have many effects on the soil, especially if buildings are standing on it that will collapse, causing soil liquefaction-induced ground settlement [18] [21] [22]. Besides, areas experiencing earthquake-induced soil liquefaction events can be repeated if the parameter of the earthquake that occurs is equal to or higher than the Palu earthquake event in 2018 [1]. ...
... Many methods are used in estimating earthquakes-induced soil liquefaction, one of which is using the SPT data procedure method developed by Idriss and Boulanger [18]. To estimate the factor of safety against soil liquefaction, it can be formulated as in the Equation (4), which is as follows: ...
The University of Tadulako suffered significant damage after a tectonic earthquake with a magnitude of M 7.5 with a depth of 20 km that occurred on September 28, 2018. This incident happened because of its location very close to the Palu-Koro fault. The Ministry of Public Works and Public Housing was assigned to reconstruct damaged educational infrastructure there. Seismic hazard analysis was needed to prepare reconstruction development projects and mitigation efforts. Many studies are related to predicting ground motion due to seismic fault activity, one of which is the attenuation NGA West 2 models. This study aims to determine the relationship between fault effects and ground motion to estimate liquefaction-induced settlement at this project. The results show that the relationship between the fault effects and ground motion affects various PGA values. PGA value resulting from the CY14 model was used to estimate settlement because it considers the worst condition aspect, where the most significant settlement occurred at the drill point DP-05 of 10.234 cm. This settlement can happen because the liquefied soil layer at the drill point was quite deep compared to other drill points.
... The argument for this was articulated by Green et al. (2022), based on liquefaction triggering being a strain phenomenon, not a stress phenomenon, and as a result, the influence of effective confining stress on liquefaction triggering varies as a function of the FS L , among other factors. In addition to the back-calculated K σ relationship from the proposed energy-based model, Fig. 5 also shows K σ relationship used by Idriss and Boulanger (2008) and the K γ relationship proposed by Green et al. (2022) assuming FS L ¼ 1. ...
... The underlying premise of the Andrus et al. (2009) approach is that the measurement of penetration resistance mobilizes intermediate to large strains that inherently disturb the soil fabric and, thus, is not that sensitive to aging effects (i.e., penetration resistance correlates to the V S of the soil, if the soil were young, regardless of the time since last disturbance). In contrast, the measurement of V S directly in the soil is Green et al. (2022), and the K σ relationship used by Idriss and Boulanger (2008) (IB08) for three different soil densities. ...
... Furthermore, and more importantly, the authors have not validated their hypothesis that the influence of initial static shear stress is inherent to the proposed energy-based model using laboratory data. Although these are planned future efforts in furthering the development of the energy-based triggering model, in the interim, the authors have developed energy-based K α relationships, K α ΔW , from the stress-based K α relationship used by Idriss and Boulanger (2008), where K α ΔW is given by ...
The most commonly used approach for evaluating liquefaction triggering is via stress-based simplified models. Proposed herein is a model for evaluating liquefaction triggering where the imposed loading and ability of the soil to resist liquefaction are quantified in terms of normalized dissipated energy per unit volume of soil (ΔW/σ'vo), computed within a total stress framework. The proposed model overcomes limitations of many previously proposed energy-based triggering models. Additionally, the proposed energy-based model unites concepts from both stress-based and strain-based procedures, overcoming some of their limitations, and in its simplified form is implemented similarly to the simplified stress-based models. An updated field case history database is used to develop probabilistic limit-state curves. These limit-state curves express ΔW/σ'vo required to trigger liquefaction as a function of corrected cone penetration test tip resistance (q c1Ncs) for different probabilities of liquefaction (PL) and have comparable predictive abilities to stress-based limit-state curves in terms of number of correct predictions for the cases analyzed. However, because dissipated energy is a scalar quantity, multidirectional shaking and other effects such as soil-structure interaction, nonvertical wave fields, and topographic site effects can readily be accounted for. Additionally, the applicability of the proposed triggering curve is not limited to earthquake loading but, rather, can be used in relation to other sources of vibrations (e.g., construction vibrations and explosive loading, among others).
... However, they are often only developed for clean sands. For example, well-established empirical correlations between DR and CPT cone tip resistance corrected for overburden pressure (qc1N) developed by Tatsuoka et al. (1990), Robertson & Cabal (2012), and Idriss & Boulanger (2008), herein denoted T90, RC12, and IB08, are shown in Eq. 1, Eq. 2, and Eq. 3, respectively. ...
... These relationships are plotted in Figure 1. Tatsuoka et al. (1990), denoted as T90, Robertson & Cabal (2012), denoted as RC12, and Idriss & Boulanger (2008), denoted as IB08. ...
... Empirical relationships between DR and SPT blow counts corrected for overburden pressure ((N1)60) have been developed by Skempton (1986), Idriss & Boulanger (2008), and Cubrinovski & Ishihara (1999), herein denoted S86, IB08, and CI99, respectively. The expressions for these relationships are of the form shown in Eq. 4. ...
Most empirical correlations between relative density (DR) and penetration resistance are derived for sands, with few exceptions. Presence of gravel in sandy soils is known to significantly influence penetration resistance through the effects of particle size and packing of the soil, and thus correlations applied to gravelly soils should account for these effects. On the other hand, well-graded reclaimed fills of gravel-sand-silt mixtures may show behaviour ranging from that of silty sand to that of clean gravel, depending on the proportion of the three fractions in the mixture. This paper illustrates the effects of grain-size on the estimation of DR based on cone penetration data by comparing correlations developed using data from sandy soils with one correlation developed specifically for soils with a wide range of grain-size composition including gravels. A major challenge in using the latter correlation accounting for grain-size effects is the evaluation of index void ratios (emax and emin), as respective laboratory tests have not yet been standardized for gravelly soils. Results from preliminary laboratory tests for the evaluation of emax and emin for gravel-sand-silt mixtures, sourced from a well-documented case study, are used as the basis to apply the correlations to two CPTs performed on reclaimed gravel-sand-silt fills and scrutinize their applicability to gravelly reclamations.
... The Idriss and Boulanger (2008) PI < 7 liquefaction susceptibility criterion is sometimes compared with the Bray and Sancio PI ≤ 12 criterion, but comparison of these criteria should consider their different definitions of liquefaction. In the use of their criterion, Idriss and Boulanger (2008) reserve the term liquefaction to soils that can be evaluated using penetration resistance (e.g., CPT tip resistance); whereas Bray and Sancio (2006) use the term liquefaction for fine-grained soils if their stress-strain responses in cyclic tests are like the stress-strain response of clean sand that are classified as liquefiable. Bray and Sancio (2008) and Boulanger and Idriss (2008) agree that clayey silt soil can be sampled effectively, and therefore, laboratory testing should be used to characterize the cyclic response of these soils so that the consequences of their responses can be evaluated. ...
... Deterministic CPT-based postliquefaction ground settlement procedures are widely used in practice (e.g., Zhang et al. 2002;Idriss and Boulanger 2008). A probabilistic CPT-based postliquefaction ground settlement procedure is required in support of performancebased earthquake engineering. ...
... The proposed probabilistic CPT-based liquefaction ground-settlement procedure employs the framework of Ishihara and Yoshimine (1992), which is the framework used in several existing procedures (e.g., Zhang et al. 2002;Idriss and Boulanger 2008). The postliquefaction volumetric ground settlement (S v ) is calculated initially as ...
... The liquefied shear strength is the critical design parameter once it is established that static or cyclic liquefaction will occur in a granular soil given its density and under the applied loads. In the literature, various manifestations of liquefied shear strength has been referred to with various terminologies including undrained steady state strength, S US (Poulos et al., 1985), residual shear strength, S r (Seed, 1987;Marcuson et al., 1990;Idriss & Boulanger, 2008), undrained critical shear strength, S CS (Terzaghi et al., 1996;Stark & Mesri, 1992), liquefied shear strength, S u;liq (Olson & Stark, 2002), and post-liquefaction strength (e.g., Sivathayalan, 1994;Vaid and Thomas, 1995;Sivathayalan and Yazdi, 2013;Chu & Wanatowski, 2014;and Weber, 2015) depending on how they are determined in laboratory or field. In this paper, the liquefied shear strength from simple shear tests (both cyclic and monotonic) is referred to as post-liquefaction strength (e.g., Vaid and Thomas, 1995;Sivathayalan and Yazdi, 2013;Chu & Wanatowski, 2014), S PL . ...
... In this paper, the liquefied shear strength from simple shear tests (both cyclic and monotonic) is referred to as post-liquefaction strength (e.g., Vaid and Thomas, 1995;Sivathayalan and Yazdi, 2013;Chu & Wanatowski, 2014), S PL . The backcalculated shear strength from field case histories is referred to as residual strength (e,g., Seed, 1987;Idriss & Boulanger, 2008;Jefferies and Been, 2015), S r . ...
... These correlations are based on the in-situ penetration resistance (from Standard Penetration Test, SPT or Cone Penetration Test, CPT), and the residual shear strength, S r , back calculated from documented flow slides. Since then, many researchers (e.g., Seed & Harder 1990;Ishihara, 1993;and Olson & Stark, 2002;and Idriss & Boulanger, 2008;Robertson, 2010;Kramer & Wang, 2015;and Jefferies & Been, 2015) have added more case history data and updated the correlation. ...
In practice, residual strength is largely determined by case histories, but the case history database is limited and there are gaps in the information available in each case. As a result, laboratory tests have continued to play a key role in determining how various factors influence residual strength. This paper presents an investigation into how factors such as particle size, particle size distribution, fines content, and compressibility influence residual strength in simple shear tests. Eleven particle size distributions of a natural soil and a tailings material, ranging from silt to fine gravel, were studied. The results were compared with case histories.
Materials of different geologic origins have meaningfully different residual strengths. Particle size and particle size distributions were both found to significantly affect residual strength as well. Residual strengths obtained from simple shear tests agreed well with those back calculated from case histories. Laboratory testing can be utilized to determine how the residual strength of a given material may compare to the case history database and can used to guide design decisions. This is an important practical finding, given the small and scattered case history database.
... A non-liquefiable layer, such as a clay layer, can be assumed to develop u e ¼ 0 during shaking. Among many methods (e.g., Youd et al. 2001;Idriss and Boulanger 2008;Robertson 2015;Cetin et al. 2018), the empirical procedure by Idriss and Boulanger (2008) is widely used for performing a liquefaction hazard analysis for a design earthquake loading, typically quantified via an expected magnitude (M w ) and peak ground acceleration (PGA). These are used to estimate the imposed demand in terms of cyclic stress ratio (CSR) in the various soil layers. ...
... A non-liquefiable layer, such as a clay layer, can be assumed to develop u e ¼ 0 during shaking. Among many methods (e.g., Youd et al. 2001;Idriss and Boulanger 2008;Robertson 2015;Cetin et al. 2018), the empirical procedure by Idriss and Boulanger (2008) is widely used for performing a liquefaction hazard analysis for a design earthquake loading, typically quantified via an expected magnitude (M w ) and peak ground acceleration (PGA). These are used to estimate the imposed demand in terms of cyclic stress ratio (CSR) in the various soil layers. ...
... The proposed procedure requires determining the settlement distribution due to post-liquefaction reconsolidation. Several empirical methods, such as Tokimatsu and Seed (1984), Shamoto et al. (1998), Wu (2002), and Idriss and Boulanger (2008), have been developed for estimating reconsolidation settlement; however, their accuracy varies between 25% and 50% (Tokimatsu and Seed 1984). Darby (2018) conducted several centrifuge tests on loose and dense sand under multiple earthquake shakings and found that the estimated reconsolidation settlement using the empirical procedures overestimated the observed measurements. ...
Axially loaded piles in liquefiable soils can undergo severe settlements due to a shaking event. During shaking, the settlement is caused by the reduction of its shaft and tip capacity from the excess pore pressures generated around the pile. Post shaking, additional pile settlement is caused by the surrounding soil settling due to reconsolidation and the associated development of drag load. A new displacement-based method is developed using a TzQzLiq analysis for designing axially loaded piles subject to seismic loading and liquefaction-induced downdrag. The new displacement-based design method offers several advancements to the state of practice forced-based design procedure by AASHTO's force-based design procedure by reasonably accounting for the mechanisms that occur on axially loaded piles during and post shaking. It accounts for the initial drag load on the pile, redistribution effects resulting in large excess pore pressures in the non-liquefied layers, and reduction in the pile's shaft and tip capacity from excess pore pressures around the pile. The new design procedure estimates the pile settlement and axial load distribution during the entire shaking event, i.e., during shaking and reconsolidation. Design steps are provided describing the procedure for obtaining design curves on the settlement and drag load on piles with varying pile lengths. The length of the piles is then selected based on serviceability criteria and the pile's structural strength. Finally, the new design procedure is applied on piles used in centrifuge model tests, and results are compared, followed by an example design problem that illustrates the applicability of the new method in practice.
... The current State of Practice (SoP) for evaluating the potential of liquefaction triggering in saturated cohesionless soils at high confining pressures relies on two components: the SoP liquefaction triggering charts and the overburden correction factor, K σ [1]. The SoP liquefaction triggering charts are mostly based on in-situ penetration tests, such as the Standard Penetration Test (SPT) and the Cone Penetration Test (CPT), or shear wave velocity tests [1], [2]. ...
... The current State of Practice (SoP) for evaluating the potential of liquefaction triggering in saturated cohesionless soils at high confining pressures relies on two components: the SoP liquefaction triggering charts and the overburden correction factor, K σ [1]. The SoP liquefaction triggering charts are mostly based on in-situ penetration tests, such as the Standard Penetration Test (SPT) and the Cone Penetration Test (CPT), or shear wave velocity tests [1], [2]. These charts are calibrated using field earthquake case histories at relatively shallow elevations, typically less than 20 meters and under vertical effective stresses less than 2 atm [3]. ...
... K σ represents the ratio between the cyclic resistance ratio (CRR) at a certain confining pressure divided by the CRR at one atmosphere considering all other aspects of the soil are the same [1]. The SoP K σ relationships are either based on undrained cyclic laboratory tests or regression analysis of liquefaction field case histories with low confining pressures, not more than 2 atm (e.g., [1], [4] - [11]) [3]. ...
The State of Practice (SoP) for assessing liquefaction triggering of cohesionless soils at high
confining pressures extrapolates the SoP liquefaction triggering charts using the overburden
correction factor (Kσ). The SoP liquefaction triggering charts are calibrated using earthquake
case histories at relatively shallow elevations with vertical effective stresses less than 2
atm, while the SoP overburden correction factor relationships are either based on undrained
cyclic laboratory tests or low-confining pressure liquefaction field case histories (< 2atm).
The reliance of the SoP liquefaction evaluation at high confining pressures on undrained laboratory
tests or field case histories with low confining pressures lacks actual representation
of the effect of high confining pressure in the field. Additionally, the preliminary findings
from the centrifuge experiments conducted by Dr. Min Ni, in her Ph.D. dissertation, on
Ottawa F-65 sand at low and high confining pressures under some plausible field drainage
conditions yielded Kσ values greater than 1.0, much greater than those from the SoP relationships.
With these experiments being representative of some possible field conditions
at high confining pressures, further research is needed to explore the behavior of Kσ at
high confining pressure under different scenarios, which can be practically achieved using
numerical simulations and parametric studies.
The work presented herein calibrates the numerical program FLAC and the constitutive
model PM4Sand to the 45-1 and 45-6 single-drainage centrifuge experiments by Dr. Min Ni
at the system level, and extends these experimental results via a parametric study to study
the effect of varying the sand layer permeability and thickness on the pore water pressure
response and Kσ. The results from the numerical calibration are found to be generally in
very good agreement with the centrifuge experiments at both confining pressures, with an
excellent agreement in the excess pore water pressure ratio and the shear stress time histories.
In addition, the Kσ from the numerical model is found to be 1.29, which is greater than 1
and very similar to the 1.28 value from the centrifuge experiments.
The calibrated models are then prepared for a three-part parametric study. Part I
studied the effect of varying the Ottawa sand permeability on the soil response when exposed
to the same earthquake. This revealed the need of not restricting the location where Kσ is
calculated to the bottom of the soil, since the elevation where the maximum excess pore water
pressure ratio reaches 0.8 changes as the permeability changes. This led to re-evaluation of the calibrated runs to determine the exact rumax = 0.8 location, with corresponding recomputation
of Kσ, which increased from about 1.3 to 1.51.
Part II of the parametric study evaluated the effect of varying the permeability of the
Ottawa sand layer on Kσ with scaling up or down of the input motion in each case to reach
a target maximum excess pore water pressure ratio of 0.8 in the whole sand layer. The
study showed an undrained Kσ greater than 1.0 (= 1.27), in contradiction with the cyclic
undrained triaxial results on Ottawa sand from Dr. Min Ni’s dissertation and the cyclic
undrained results on sands from the literature. However, the study provided an increasing
Kσ versus permeability trend that further supports the results from the centrifuge tests by
Dr. Min Ni. Kσ is found to increase with permeability until an approximate permeability
of 0.001 cm/sec, where Kσ levels off at around 1.50. Additionally, the location where the
maximum excess pore water pressure ratio occurs is found to move downwards in the soil
profiles as the permeability increases, for both confining pressures of 1 and 6 atm.
Part III of the parametric study focused on the effect of varying the thickness of the
Ottawa sand layer on Kσ. It revealed that Kσ decreases as the soil thickness increases, down
to an approximate thickness of 5 m, and then levels off at an approximate value of Kσ =
1.50, which is the same value at which Kσ leveled off for a thickness of 5 m when increasing
the permeability from zero to 0.012 cm/sec. Moreover, the location where the maximum
excess pore water pressure ratio occurs is found to move upward in the soil profile as the soil
thickness increases, regardless of confining pressure, which is the opposite to the behavior
noticed when the soil permeability increases.
... A unified framework for identifying gravel interference is possible if we can apply the non-dimension approach of Pires-Sturm and DeJong (2022) to the guidance of Seed et al (2003) and Idriss and Boulanger (2008). Based on discrete element modeling (DEM) by Daniel et al. (2008), we expect open-ended penetrometers will behave in a plugged fashion when driving in gravelly soils; therefore, it is reasonable to define Dprobe as the SPT outer diameter (2 inches) rather than the inner diameter (1.375 inches). ...
... Based on discrete element modeling (DEM) by Daniel et al. (2008), we expect open-ended penetrometers will behave in a plugged fashion when driving in gravelly soils; therefore, it is reasonable to define Dprobe as the SPT outer diameter (2 inches) rather than the inner diameter (1.375 inches). As such, Seed et al (2003) would predict gravel interference for the SPT at Dprobe/D50 ratios lower than 8, while Idriss and Boulanger (2008) would predict gravel interference for Dprobe/D85 ratios lower than about 10 (assuming D85 is about 0.2 inches, larger than the No. 4 sieve per the USCS definition of gravel). These thresholds for the SPTs are consistent with the recommendations of Pires-Sturm and DeJong (2022) for CPTs, and it may be reasonable to adopt similar criteria for identifying gravel influence on other penetrometers. ...
The California Division of Safety of Dams (DSOD) regulates an inventory of over 1,200 dams. Many of these dams are founded on or constructed from gravelly soils, which can be challenging to characterize and evaluate using conventional techniques. Although most practitioners acknowledge the potential for penetration test values to be artificially elevated in gravelly soils, there is a broad range of opinions regarding the best practices for identifying gravel interference and applying corrections to site-specific data. This paper provides guidance for anticipating and evaluating gravel interference on penetration testing at dams. Special provisions should be incorporated into geotechnical investigation plans for sites where gravelly soils are suspected or known to be present. The scope of these provisions can vary depending on the investigation objective, but the overall purpose is to ensure that enough contextual information is recorded to evaluate data quality. Once this information is available, the penetration test data should be evaluated for gravel interference by considering the geotechnical and geologic circumstances at each test interval. We have also found probe-to-particle-diameter ratio to be an effective screening parameter that is preferable to any rule-of-thumb criterion based on gravel percentage alone. After data validation is complete, the higher confidence data can be applied to engineering analyses. This paper demonstrates how a unified geotechnical and geologic approach to gravelly soil characterization is beneficial for dam safety evaluations.
... Beban statik maupun siklik yang berlangsung cepat menyebabkan peningkatan tekanan air pori tanah dan menurunnya tegangan efektif tanah secara drastis. Hal tersebut mengakibatkan tanah kehilangan kekuatannya (Idriss & Boulanger, 2008;Kramer, 1996). Di beberapa tempat, likuifaksi ditandai dengan adanya retakan lateral, penurunan tanah maupun sand boiling (Idriss & Boulanger, 2008). ...
... Hal tersebut mengakibatkan tanah kehilangan kekuatannya (Idriss & Boulanger, 2008;Kramer, 1996). Di beberapa tempat, likuifaksi ditandai dengan adanya retakan lateral, penurunan tanah maupun sand boiling (Idriss & Boulanger, 2008). Bencana akibat likuifaksi menyebabkan kerusakan infrastruktur bahkan korban jiwa yang cukup besar. ...
Likuifaksi merupakan fenomena dimana tanah pasir lepas dalam kondisi jenuh air kehilangan kekuatannya akibat dari beban statik maupun dinamik yang umumnya diakibatkan oleh gempa bumi. Beban statik maupun dinamik yang disalurkan kedalam tanah tersebut menyebabkan peningkatan tekanan air pori yang signifikan sehingga tegangan efektif tanah menjadi hilang. Fenomena likuifaksi beberapa kali terjadi di Indonesia, seperti fenomena likuifaksi di Yogyakarta tahun 2006, Lombok dan Palu tahun 2018. Salah satu metode untuk menilai likuifaksi dapat menggunakan pengujian triaksial statik dengan menerapkan kondisi consolidated undrained (CU). Pada studi ini, pengujian triaksial pada kondisi CU diterapkan untuk menguji potensi likuifaksi pada tanah pasir silika Rembang. Pengujian dilakukan pada kondisi tanah pasir lepas dengan kepadatan relatif dan tanah pasir setengah padat dengan . Agar rencana tercapai, metode pemadatan basah diterapkan dalam mencetak sampel. Selama pengujian, tegangan efektif yang diberikan pada sampel sebesar 100 kPa dan 400 kPa. Hasil pengujian menunjukkan bawah tegangan air pori pada kepadatan relatif 10% cenderung naik sampai dengan nilai tegangan efektif yang diberikan. Hal tersebut menyebabkan tanah kehilangan tegangan efektifnya dan mengalami likuifaksi. Sedangkan pada kepadatan relatif 40%, tegangan air pori akan mencapai puncak dan selanjutnya konstan sehingga tanah dapat menjaga kekuatannya.
... 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]. ...
... LSI was determined using the Sonmez and Gokceoglu method [20], which was developed from Iwasaki et al. method [21]. LSI was calculated based on the liquefaction SF value from the surface to a depth of 20 meters with equations (16) to (17). ...
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.
... The effect of vertical effective overburden stress, σ 0 v0 , on the cyclic response of cohesionless soils commonly is addressed using the overburden correction factor, K σ , introduced by Seed (1983). Increases in σ 0 v0 lead to the suppression of dilation and the corresponding reduction in undrained cyclic resistance (Idriss and Boulanger 2008). Previous investigations of the effect of σ 0 v0 on the cyclic resistance of granular soils have been conducted using undrained stress-controlled cyclic laboratory tests (Seed 1983;Seed and Harder 1990;Harder and Boulanger 1997;Vaid and Thomas 1995;Vaid and Sivathayalan 1996;Hynes and Olsen 1999) to build a body of experimental data to inform trends in K σ with σ 0 v0 and adjustments to the cyclic resistance computed using penetration test-based liquefaction triggering procedures. ...
... (1) by normalizing CRR with respect to the CRR of specimens consolidated to σ 0 vc ¼ 100 kPa. However, because σ 0 v0 for the intact OC specimens was larger than the reference σ 0 vc ¼ 100 kPa (i.e., Site E-5: σ 0 v0 ¼ 125 kPa; and Site F: σ 0 v0 ¼ 120 kPa), K σ was computed using CRRs estimated for σ 0 vc ¼ 100 kPa through limited nonlinear interpolation of the observed variation of τ cyc with σ 0 vc for a given N using curves fitted to the available data through the origin as described by Idriss and Boulanger (2008). Despite a 29% reduction in void ratio for the intact Site E specimens as σ 0 vc increased from ∼100 to 600 kPa, the CRR at N γ¼3% ¼ 30 decreased from 0.26 to 0.15, with a corresponding K σ ¼ 0.58. ...
The effect of vertical effective consolidation stress, σ 0 vc , on the cyclic resistance of nonplastic to plastic normally consolidated (NC) and overconsolidated (OC) intact and NC reconstituted silt was investigated using a series of constant-volume, stress-controlled cyclic direct simple shear (CDSS) tests. The results were interpreted considering the changes of specimen properties [e.g., void ratio, e, and over-consolidation ratio (OCR)] associated with the increased σ 0 vc. Despite increasing density, all specimens exhibited a reduction in cyclic resistance as σ 0 vc increased. The reduction in cyclic resistance for intact specimens occurred due to the detrimental effect of yielding of the natural soil fabric, reduction in OCR, and the potential suppression of dilative tendencies, which outweighed the beneficial effect of reduced e. Tests of uniformly prepared reconstituted NC specimens reduced the number of factors contributing to the reduction of cyclic resistance (i.e., destruction of natural soil fabric, and reduction of OCR) with increased σ 0 vc , and were used to confirm the sensitivity of cyclic resistance to σ 0 vc , in which the detrimental effect of suppressed dilative tendencies on cyclic resistance dominated the beneficial effect of reduced e. The overburden correction factor, K σ , was observed to decrease with increased plasticity index, PI, highlighting the role of compressibility on cyclic resistance.
... More recent models based on the cone penetration test (CPT) have been widely adopted because of the CPT's superior repeatability and nearly continuous profiling relative to the SPT. However, these methods (e.g., Zhang et al., 2002;Yoshimine et al., 2006;and Idriss and Boulanger, 2008) still suffer from being validated against a limited number of field case histories. Consequently, these procedures were developed deterministically with no quantification of the uncertainty of the liquefaction-induced ground settlement estimate. ...
... An estimate of FC is also required in routine triggering methods as well as in other informative correlations. Idriss and Boulanger (2008) recommend measuring the FC directly from representative samples; however, this may not be practical in many engineering applications. Even though discrepancies between Ic and FC classifications are expected (e.g., Robertson, 2009a;and Beyzaei et al., 2018b), correlations between Ic and FC have been proposed and implemented in practice and research. ...
... A key requirement in the application of these laboratory-based relationships to sand deposits in the field is to estimate the relative density of the sand using a field-based parameter (i.e., the cone tip resistance in the case of CPT-based assessment). This conversion involves significant uncertainties, as illustrated in Figure 2a showing correlations of DR with clean-sand equivalent cone tip resistance (qc1Ncs), for clean sands developed by Tatsuoka et al. [9], Robertson & Cabal [10], and Idriss & Boulanger [11]. Tatsuoka et al. [9], denoted as T90, Robertson & Cabal [10], denoted as RC12, and Idriss & Boulanger [11], denoted as IB08, and (b) the Cubrinovski & Ishihara [5] SPT correlation with SPT-to-CPT conversion QNR values as noted for soils of varying grain-size distributions. ...
... This conversion involves significant uncertainties, as illustrated in Figure 2a showing correlations of DR with clean-sand equivalent cone tip resistance (qc1Ncs), for clean sands developed by Tatsuoka et al. [9], Robertson & Cabal [10], and Idriss & Boulanger [11]. Tatsuoka et al. [9], denoted as T90, Robertson & Cabal [10], denoted as RC12, and Idriss & Boulanger [11], denoted as IB08, and (b) the Cubrinovski & Ishihara [5] SPT correlation with SPT-to-CPT conversion QNR values as noted for soils of varying grain-size distributions. ...
Gravelly soils are not well represented in current semi-empirical liquefaction evaluation procedures, which raises the question whether state-of-the-practice liquefaction evaluation methods, which are predominantly based on clean sands and sands with fines, are applicable to gravelly soils. In particular, the Cone Penetration Test (CPT) liquefaction settlement evaluation procedure uses empirical correlations between relative density (DR) and penetration resistance based on laboratory tests of clean sand. These procedures therefore do not account for the effects of particle size on penetration resistance through the effects of the packing of the soil. This paper investigates the applicability of a CPT-DR correlation developed for a wide range of liquefiable soils including gravels in the liquefaction-induced settlement evaluation for well-graded reclaimed gravelly soil. The correlation is first shown to capture the effects of grain size composition on the penetration resistance through the index void ratios emax and emin. A developing novel methodology for evaluation of emax and emin for gravel-sand-silt mixtures including results from preliminary laboratory tests are then presented. Finally, results of liquefaction-induced settlement estimates based on the employed CPT-DR correlation are compared with results obtained using sand-based empirical correlations for the well-documented liquefaction case history of CentrePort (New Zealand). Results show that sand-based procedures for evaluation of liquefaction-induced settlement are found to overestimate the relative density and consequently underestimate post-liquefaction settlement of gravelly soils as compared to using correlations accounting for grain-size effects on penetration resistance, particularly at medium to high densities. However, these differences are smaller for well-graded gravels that have a dominant silty sand fraction in the soil matrix deposited in a loose state.
... The spatial mapping was done using ArcGIS platform whereas the graphical presentations were made with the use of Origin software. Idriss and Boulanger (2008) propounded an SPT-based method that was approved to analyze the FOS. This technique predicts the FOS against liquefaction for each layer based on SPT blow count data and geotechnical characteristics of the soil layers. ...
... • Through the study, it is observed that the widely used standard procedure by Idriss and Boulanger (2008) and Iwasaki et al. (1982) are effective in liquefaction susceptibility evaluation in Kathmandu Valley for 2015 Gorkha earthquake scenario. • The majority of valley ground is found to have medium to very high liquefaction susceptibility and risk. ...
Histories of earthquakes in Nepal have shown substantial liquefaction in several regions of the nation, including the capital, Kathmandu Valley. Despite being a liquefaction sensitive zone, Kathmandu Valley soil in Nepal has little studies on liquefaction potential. As a heavily populated metropolitan area, the evaluation of the valley’s liquefaction potential is vital for assuring the safety of engineered structures. We utilised the geotechnical database collected from 400 locations to conduct quantitative analyses and modelling to evaluate the valley soil’s susceptibility of liquefaction in two scenario earthquakes. Some of the most widely used and existent methods based on deterministic and probabilistic approaches are used for the assessments, and the results are shown as liquefaction hazard maps indicating liquefaction potential index (LPI) and probability of liquefaction (PL). Most of the valley’s areas are moderately to extremely prone to liquefaction, and the valley’s central and southern regions are more susceptible to liquefaction and at greater risk of liquefaction damage than the northern sections. Results of the evaluation are corroborated by the field manifestations of the 2015 Gorkha Earthquake.
... The liquefaction resistance curve determines the relationship between CSR and NL (N to liquefaction at ε DA = 5% ). Figure 8 depicts the liquefaction resistance curve of Soil A with σ c ʹ = 100 kPa and = 40%. Each test-related data point was fitted with a power-law function [42]: ...
... Figure 8 depicts the liquefaction resistance curve of Soil A with σ c = 100 kPa and D r = 40%. Each test-related data point was fitted with a power-law function [42]: ...
Many laboratory studies have shown that particle size distribution (PSD) affects the liquefaction susceptibility of granular materials. However, few studies have focused on the impact of PSD on coral particles. In this study, two different soil families were prepared: one with three levels of mean particle size (D50) with identical uniformity coefficient (Cu)and the other with four levels of Cu with the same D50 for coral gravelly soils. In addition, a series of undrained cyclic triaxial tests were conducted on coral gravelly particles with two groups of PSDs at a relative density of 40% and an adequate confining pressure of 100 kPa. The test results indicated that D50 with identical Cu can affect the undrained cyclic behavior of coral gravelly particles. In contrast, Cu with identical D50 does not impact the undrained cyclic behavior of coral gravelly particles. The developing pore water pressure was uniform when the sample was subjected to the same cyclic loading. For samples with changing D50 values of 2.35, 4.70, and 7.05 mm, increasing D50 improved the cyclic liquefaction resistance. For samples with changing Cu, increasing Cu in the range of 1.06–5.00 first increased and then decreased the liquefaction resistance.
... Nonplastic and low-plasticity silts present distinct challenges for the estimation of cyclic resistance, as no V s -based method is available, low plasticity silts are usually not well-represented in case history databases, and penetration resistance may be significantly affected by partial drainage during penetration (McNeilan and Bugno 1985;DeJong et al. 2012). CPT-based liquefaction triggering methods, for example, may treat partial drainage effects and hence penetration resistance indirectly through fines content (FC) corrections to the overburden stresscorrected cone tip resistance, usually represented using the term q c1Ncs (e.g., Youd and Idriss 2001;Idriss and Boulanger 2008). Yet, databases are constituted with numerous case histories where laboratory measured FC is unavailable for the critical layer, and, when available, the number of cases with FC > 50% and corresponding to silts is low [e.g., ∼10% of cases in the Boulanger and Idriss (2014) database]. ...
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.
... Liquefaction resistance Figure 5 depicts the relationship between the number of cycles to liquefaction and CSR, known as the liquefaction resistance curve (CSR-N liq ) for clean and clayey Toyoura sands with different degrees of saturation at the same initial state (e 0 = 0•791 and c p = 100 kPa). Generally, N liq increases with a decrease in CSR, and this relationship can be represented by a power equation with two positive constants, a and b, as follows (Idriss & Boulanger, 2008;Ulmer et al., 2022) liq ...
Experiences from previous earthquake events indicated that sands containing non-plastic (silt) or plastic (clay) fines are susceptible to liquefaction. These experiences underline the need for improving the fundamental understanding of the seismic behaviour of silty and clayey sands and for developing appropriate methods to evaluate their liquefaction potential. This paper presents an attempt to elucidate the integrated effects of fines (non-plastic silt and plastic clay) inclusion and degree of saturation on the cyclic behaviour and liquefaction resistance of sands based on systematic experiments. One of the notable findings of the study is that, apart from the familiar mode of cyclic mobility, clayey sand can also undergo flow-type failure under either fully or partially saturated conditions. The unified correlation between the cyclic resistance ratio (CRR) and the state parameter (ψ), established earlier for clean and silty sand in the framework of critical state soil mechanics (CSSM), is found to work for clayey sand as well. Furthermore, it is shown that the impact of saturation on the cyclic strength of clean and clayey sands can be reasonably characterised using the compression wave velocity normalized by the shear wave velocity.
... One of the few cases is the 1964 Niigata earthquake in Japan, which caused significant damage to several dams in the region. Post-earthquake reconnaissance revealed that the cracks and deformations were caused by soil liquefaction beneath the dam foundations, leading to improved design and construction practices that are still used today (Idriss and Boulanger, 2008). Traditional post-earthquake safety inspections of dams were carried out using field visual inspection methods, which had limitations in grasping three-dimensional deformation information on large-scale dam facilities. ...
Post-earthquake reconnaissance is an important process for assessing the safety of massive structures. Dams are critical structures that require evaluation following an earthquake, as dam failure can lead to significant damage to the surrounding area. This paper presents drone (unmanned aerial vehicle) photogrammetry-based reconnaissance of the Angat Dam (Philippines), which has stabilizing fill, following the M 6.1 Luzon earthquake in April 2019. The author presents the results of visual inspection, drone digital mapping, and seismically induced deformation monitoring, as well as a general interpretation of dam safety. Analysis of the instrumentation data did not indicate that any significant changes in crest settlement, piezometric head, or seepage rate resulted from the earthquake. However, seismically induced longitudinal cracking along the dam crest was observed in the drone photogrammetry. The digital surface model, orthoimage, and as-built GIS geometry characterizations generated using the drone photogrammetry facilitated the geospatial analysis of seismic cracking and deformation. It is found that the uplift deformation was caused by counteracting effects between the existing dam body and its stabilizing fill. It is concluded that the results obtained using drone digital mapping are a valuable reference for future deformation monitoring using regular mapping methods in a 3D geospatial digital model.
... However, a substantial portion of the Global database was compiled from the same databases used to develop commonly used triggering curves (e.g. Boulanger and Idriss, 2014;Idriss and Boulanger, 2008;Moss et al., 2006;Robertson and Wride, 1998). Therefore, these uncertainties are also present in previous triggering and manifestation models. ...
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.
... Many earthquake engineering applications require an estimate of the ground-motion duration in addition to an estimate of the amplitude. For example, ground-motion duration is a key parameter in geotechnical engineering applications involving nonlinear deformation regimes, such as liquefaction analysis or large deformation numerical modeling (Seed, 1975;Bray and Travasarou, 2007;Idriss and Boulanger, 2008;Bray and Olaya, 2022). Duration is also required for applications of random vibration theory to estimate the peak amplitudes in the time domain from a Fourier amplitude spectrum (Rathje and Kottke, 2008). ...
A duration ground-motion model for crustal earthquakes based on the normalized Arias intensity (IA) is developed. Two sets of seismological simulations are used to constrain the form and scaling of the duration model. Simulations using a 3D crustal model show that an additive model for the source, path, and site terms captures the physical behavior of duration better than a multiplicative model for the site term. Stochastic finite-fault simulations are used to constrain the saturation of the large-magnitude scaling at short distances. The duration model is developed in two parts: a duration model for the time interval between 5% and 75% of the normalized Arias intensity (D5−75) and a duration model for the ratio of the D5−X/D5−75 duration for X values from 10 to 95. Together, these two models provide a more complete description of the evolution of the seismic energy with time than a single duration metric. A new aspect of the statistical model for duration is the inclusion of a random effect for the path term in addition to random effects for the source and site terms. The source and site random effects are modeled as scale factors on the duration, whereas the path-term random effect is a scale factor on the distance slope. The distribution of the duration residuals has a skewness that is between the skewness of a lognormal distribution and the symmetry of a normal distribution. The final duration aleatory variability is modeled by a power-normal distribution with an exponent of 0.3, which accounts for the amplitude dependence of the aleatory variability of the duration with smaller aleatory variability for large-magnitude events and larger aleatory variability for small-magnitude events as compared to the variability from a lognormal distribution.
... In a recent study, Chakraborty and Sawant [25,32,33] have shown a detailed calibration of the UBC3D-PLM material model parameters, which is mainly based on best-fit liquefaction strength curve against the equation provided by Idriss and Boulanger [35]. Depending on the parameters chosen for best-fit liquefaction strength curve, these parameters are further validated with the laboratory test results for different loading conditions. ...
The present study focused on gravel berm and stone column improvement techniques for mitigating the effects of liquefaction for an embankment resting on liquefiable ground. Three-dimensional finite element models are developed to evaluate the effectiveness of two countermeasure techniques for embankments resting on liquefiable soil. Three different embankment models are considered in this study as benchmark embankment model (BM), gravel berm embankment model (GBM), and stone column mitigation model (SCM). Foundation soil has been modeled using an elasto-plastic effective stress-based UBC3D-PLM model. Initially, the behaviour of three different embankment models (BM, GBM, and SCM) are evaluated under varying amplitude of cyclic input motion. Later, a seismic study is carried out considering 10 sequential earthquake motions to assess the effect of the aftershock following the main shock event. It can be seen that even small amplitude aftershocks can develop a high excess pore pressure ratio in the foundation soil, especially below the embankment toe. Moreover, a linear correlation has been observed between the input motion Arias intensity and the intensity at the embankment crest. In an overall observation, stone column mitigation was found to be a sound mitigation approach.
... This study followed the procedure proposed by Park et al. (2015) and Mei et al. (2018)to select the input parameters of the PA model. Similarly, relative density is the most important input information estimated with SPT blowcounts(Idriss and Boulanger, 2008). ...
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.
... 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 ). ...
... To assess the liquefaction potential of soil deposits based on the SPT dataset, the methodology proposed by Idriss and Boulanger (2008) was discussed in this paper. The calculation of the cyclic stress ratio (CSR) and cyclic resistance ratio (CRR) was performed using Eqs. ...
Assessing the potential for liquefaction using traditional experimental or empirical analysis procedures is both time-consuming and arduous. Employing a machine learning model that can accurately predict liquefaction potential for a specific site can reduce the time, effort, and associated costs. This study proposes several empirical machine learning models, including deep neural network (DNN), convolutional neural network (CNN), recurrent neural network (RNN), long short-term memory (LSTM), and bi-directional long short-term memory (BILSTM), to assess the liquefaction potential of soil deposits based on SPT-based post liquefaction datasets. To train the proposed models, a dataset comprising 834 liquefied and non-liquefied cases was collected to perform the liquefaction analysis. A Pearson correlation matrix was also conducted to examine the correlation between soil and seismic parameters and the probability of liquefaction. Furthermore, a sensitivity analysis was adopted to assess the impact of soil and seismic parameters on the probability of liquefaction. The proposed model's prediction capability was assessed using several performance indices, including rank analysis, accuracy matrix, and AIC criteria. The comparative analysis of the proposed models' predictive ability to determine liquefaction probability revealed that the RNN model outperformed the others, displaying the highest accuracy and lowest error index values. Subsequently, the RNN model achieved the first rank with a total score value of 70, followed by the CNN (55), DNN (52), BILSTM (47), and LSTM (16) models. The parametric analysis, rank analysis, accuracy matrix, and AIC criteria collectively demonstrate the proposed models' ability to predict liquefaction probability. Furthermore, the robustness of these models was assessed through external validation and comparative analysis.
... Lateral spreading refers to large permanent horizontal ground deformations and is a major geohazard in earthquake-prone regions (e.g. Idriss and Boulanger, 2008). These lateral deformations commonly occur in the presence of gently sloping ground and/or free faces (e.g. ...
Liquefaction-induced lateral displacements represent a major geohazard in earthquake-prone regions, yet the uncertainty associated with their prediction remains notoriously high. Documented observations after recent earthquakes provide evidence that depositional environment-specific geologic conditions play a crucial role in liquefaction susceptibility, and in the severity and spatial extent of liquefaction-induced ground deformations. However, this evidence is largely qualitative in nature, which limits the potential to incorporate the effects of depositional processes and environments in the next generation of lateral spreading predictive models. This study provides a framework to quantitatively assess the relationship between depositional environment-specific geologic factors and lateral spreading by means of simple fluvial geomorphic facies models, geotechnical engineering data (e.g. Cone Penetration Test data), and geospatial analytics. Three hypotheses are introduced and tested using lateral spreading ground deformations observed following the 2011 Christchurch earthquake along the Avon and Heathcote rivers in New Zealand. The results from this study indicate that the presence of an active (i.e. with active sediment deposition) compared to inactive (e.g. abandoned) channels is the most important fluvial geomorphologic variable out of the three tested. The other two are associated with the location relative to the meander bend position, including location within the point bar (inside) or the cut bank (outside), and upstream versus downstream within a given point bar. Findings from this study show that more lateral spreading occurs within point bars, and upstream (within a given point bar) in simple meander bends. However, the presence of geomorphic complexities (e.g. cut banks connected to an incised channel or tributary and/or channel confinement) can challenge the unbiased quantification of the contribution of a single geomorphic variable to the observed lateral displacements. These findings can be applied to other fluvial environments outside of New Zealand, and the proposed framework can be implemented for other non-fluvial depositional settings.
... High groundwater levels can lead to water-saturated soil conditions, which makes the soil susceptible to liquefaction during an earthquake. By calculating the value of soil to liquefaction due to cyclic loading, cyclic resistance ratio (CRR), and soil shear stress due to cyclic loading, cyclic stress ratio (CSR), analysis of liquefaction potential was carried out in this study using a simplified procedure method developed by Idriss & Boulanger (2008) [11]. The CSR value is the cyclic stress that triggers liquefaction. ...
Construction of the Solo – Yogyakarta – NYIA Kulon Progo Toll Road Section I.2 is a part of Java's toll road network system that connects Solo and Yogyakarta. The presence of this opak fault allegedly cut the toll road alignment. Based on Indonesia's Liquefaction Vulnerability Zone Map, the alignment location is in a medium liquefaction vulnerability zone. This study aims to determine the potential of liquefaction in the construction of Solo – Yogyakarta – NYIA Kulon Progo Toll Road Section I.2 (stationing 29+000 - 36+000). The maximum peak ground acceleration on the surface was calculated using the Deterministic Seismic Hazard Analysis calculation. Calculating liquefaction potential analysis uses the simplified procedure method developed by Idriss and Boulanger. The research shows that ten borehole points with sandy soil types 2 m – 18 m below the surface have liquefaction potential. The depth of the groundwater table is between 0.2 m – 10 m below the ground surface. Based on the Liquefaction Potential Index analysis, the research location is in a low - high level of liquefaction vulnerability.
... Seed's simplified procedure is the first method to estimate the liquefaction of saturated soil. Due to its simplicity to understand and operate in evaluating liquefaction potential, Seed's simplified method [5] and its modified versions [6,7] as the standard method of liquefaction evaluation of free fields have been widely applied. ...
... In this sense, they represent a lower limit to the resistance to liquefaction of sands. The procedure to compute the qc1Ncs-based curves plotted in Figure 5 is detailed in Cubrinovski et al. (2017); qc1Ncs values have been converted to equivalent relative densities DR using the relationship indicated by Idriss & Boulanger (2008). Figure 5 shows that the liquefaction resistance recorded in the DSS tests for water sedimented Christchurch sand specimens (red curves) is higher than the qc1Ncs-based resistance (dashed lines) for similar values of relative density. ...
... Thus, the higher the value of resistance to liquefaction, the higher the increase in the content of fine sand and the increase in the relative density of sand. In monotonic or cyclic loading, the stressstrain in saturated sand is very dependent on the relative density of the sand [30]. ...
... The target value of CRR is based on the liquefaction triggering correlation proposed by Idriss and Boulanger (2008). This formulation provides target CRR values for an effective overburden stress of 1 atmosphere and an earthquake magnitude of M=7.5, considering the corresponding SPT (N1) ...
This study focused on nonlinear effective stress site response analysis using two coupled constitutive models, that is, the DM model (Dafalias and Manzari 2004), which incorporated a simple plasticity sand model accounting for fabric change
effects, and the PMDY03 model (Khosravifar et al. 2018), that is, a 3D model for earthquake-induced liquefaction triggering and postliquefaction response. A detailed parametric study was conducted to validate the effectiveness of nonlinear site response analysis and porewater pressure (PWP) generation through a true coupled formulation for assessing the initiation of liquefaction at ground level. The coupled models demonstrated accurate prediction of liquefaction triggering, which was in line with established empirical liquefaction triggering relations in published databases. Several limitations were identified in the evaluation of liquefaction using the cyclic stress method, despite its widespread implementation for calculating liquefaction triggering. Variations in shear stiffness, represented by changes in shear wave velocity (Vs1), exerted the most significant influence on site response. The study further indicated that substantial differences in response spectra between nonlinear total stress and nonlinear effective stress analyses primarily occurred when liquefaction was triggered or on the verge of being triggered, as shown by excess PWP ratios approaching unity. These differences diminished when liquefaction occurred towards the later stages of intense shaking. The soil response was predominantly influenced by the higher stiffness values present prior to
liquefaction. A key contribution of this study was to validate the criteria used to assess the triggering of level-ground liquefaction using true coupled effective-stress constitutive models, while also confirming the reliability of numerical approximations including the PDMY03 and DM models. These models effectively captured the principal characteristics of liquefaction observed in field tests and laboratory experiments.
... The safety factor is determined by considering the cyclic resistance ratio (CRR) of the soil against liquefaction and the cyclic stress ratio (CSR) induced by the earthquake. Equation 2.19 presents the safety factor calculated using the corrected SPT-(N1)60 values proposed by Youd et al. (2001) and Idriss and Boulanger (2008). Moreover, Equ. 14 incorporates the effect of the magnitude scaling factor (MSF) on the safety factor against liquefaction. ...
Dynamic loads such as earthquakes can cause major failure to soil, and the foremost of these failure is soil liquefaction. In engineering studies, liquefaction analyses can be performed by different methods based on the results of field and laboratory experiments. In this study, the liquefaction potential of the soils of the Batman settlement zone, located close to the East Anatolian Fault Zone in Türkiye, was evaluated. In the study area, Meydan site consists of low-medium plasticity clay (CL) at a depth of 1.5–3 m and silty sand (SM) at a depth of 3.5–12.45 m; Bahçelievler site consists of low-medium plasticity clay (CL) at a depth of 1.5–7 m and silty sand (SM) at a depth of 7–15 m. For liquefaction analysis, magnitudes and accelerations of design earthquake were selected as 0.30 g for accelerations, and 7.5 and 6.5 for magnitudes. For this purpose, the effects of soil and earthquake parameters on soil liquefaction were evaluated using the standard penetration test (SPT) and shear wave velocity (Vs) methods with the Microsoft Excel-based SoilEngineering program and the obtained results were correlated and discussed. It is emphasized in this work that liquefaction potential analyses using soil and earthquake parameters provide more reliable results. In addition, the soil strata of locations where the liquefaction risk potential is high were found to have total settlement of approximately 36.87 to 36.2 cm, parallel to the high liquefaction risk, and it was determined that there may be high settlement in the area.
... , 2the authors have performed the SPT borehole drilling and logging, particle size distribution,3 plasticity chart, bedrock mapping, groundwater level mapping and the study of liquefaction 4 compositional criteria. The spatial mapping was done using the ArcGIS platform whereas the 5 graphical presentations were made with the use of Origin software.Boulanger (2008) propounded an SPT-based method that was approved to analyze the 9 ...
Despite being a liquefaction susceptible zone, Kathmandu Valley soil in Nepal has limited studies on liquefaction potential and most of them are based on the deterministic approach. Although this method is widely used, it ignores the uncertainties of seismic parameters such as peak ground acceleration, a max, and earthquake magnitude, M w as well as the inherent variabilities of soil layers, in-situ testing procedures, and geotechnical properties. On the other hand, the probabilistic approach helps assess the liquefaction potential by considering all these uncertainties. In this study, we assess the liquefaction hazard in the Kathmandu Valley using the first-order second-moment (FOSM) method as a probabilistic approach for liquefaction hazard assessment. The assessment is done for three likely-to-recur scenario earthquakes utilizing the geotechnical data of 1510 boreholes. The soils are characterized geotechnically to further assess susceptibility criteria of liquefaction in the valley. The assessment reveals that the central part of the valley is more vulnerable to liquefaction than other parts and the liquefaction probability increases with increasing depth up to 9 m, after which has geared down the value. Moreover, a relationship between the probability of liquefaction ( P L ) and the factor of safety (FS) against liquefaction is established. The hazard maps prepared for different earthquake scenarios can be useful for future infrastructure planning in Kathmandu Valley.
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.
The seismic cone penetration test (SCPT) was developed in the early 1980s and significant developments have been made in its use and application. This paper provides a review of these developments with particular emphasis on its application to identify soil microstructure. The Ménard pre-bored pressuremeter test (PMT) is one of the most popular in situ tests in France and links between SCPT results and the PMT are suggested.
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
Earthquakes that induced liquefaction have occurred in several regions in Indonesia, including Bantul Regency during the 2006 Bantul earthquake. The study location is the Kretek 2 Bridge in the Opak River Estuary, Bantul Regency, Yogyakarta Special Region Province. This area features medium-dense sandy soil with a high liquefaction potential. This study estimated the safety factors related to liquefaction using a simplified procedure. In addition, this study analyzed the quantitative index of liquefaction potentials using the Liquefaction Potential Index (LPI), Liquefaction Reduction Number (LRN), Liquefaction Risk Index (LRI), Liquefaction Severity Index (LSI), Liquefaction Displacement Index (LDI), and Post-liquefaction Settlement approaches. The results showed that liquefaction occurred predominantly at a depth of 1.5-6 m. For the LPI and LRN, the soil was classified as "very low" to "high" and "low" to "very high" for liquefaction potential, respectively. While the LRI result was in the "low" to "medium" risk categories, the LSI output was in the "non-liquefied" to "low" severity classification. The LDI and post-liquefaction settlement calculated by 1-D reconsolidation were 3.9 m and 0.12 m, respectively. Each method has different results; the LPI and LRN are more inclined to the possibility of a liquefaction event occurring, while the LRI and LSI emphasize the level of risk and severity of liquefaction damage. Furthermore, the LDI and post-liquefaction settlement are indicators of area damage measured in meters horizontally and vertically if liquefaction occurs.
In June 2019, the Asian Development Bank approved emergency rehabilitation and reconstruction assistance (EARR) to help Indonesia rebuild better critical infrastructure damaged by the 2018 Palu-Donggala earthquake. One of the EARR sub-projects is the reconstruction of Universitas Islam Negeri (UIN) Datokarama that suffered significant damage from the combined effects of the tsunami and earthquake. The design for the building's reconstruction incorporated better principles of deconstruction, including pile foundations to ensure the facilities are earthquake, tsunami, and liquefaction resistant. This study purpose is to evaluate liquefaction potential and estimate its severity or damage potential to structures in the reconstruction site. Liquefaction potential will be assessed in two ways, first by using soil deposits grain sizes distribution method from Japan technical standards for port and harbour facilities and second by safety factor against liquefaction (FOS) method using the SPT-based liquefaction triggering analysis with the revised magnitude scaling factor (MSF) relationship by Idriss and Boulanger. Liquefaction Potential Index (LPI) from Iwasaki will be used for estimating liquefaction severity. The analysis is performed on dataset taken from 6 boreholes in location dominated by saturated sandy soil and shallow ground water. Based on the result, liquefaction potentially triggered at various depth with consistent LPI index at > 15, The reconstruction site has a very high liquefaction risk.
On September 28, 2018, liquefaction in Sibalaya damaged irrigation canals and hit 51.2 hectares fields and roads. This phenomenon was triggered by an earthquake of magnitude 7.5 that shook Sigi Regency, Central Sulawesi Province. As an increase in soil pore water pressure is one of the causes of liquefaction, the pore water pressure ratio (ru) at the study site was analyzed. Then, this figure is used as a point of reference to determine the liquefaction potential. Standard Penetration Test (SPT) data and laboratory tests from four boreholes resulting from soil investigations in 2021 with a maximum depth of 20 meters were utilized in this study, along with microtremor data down to the depth of bedrock from test results in 2023. Based on the data, the liquefaction potential was assessed using the one-dimensional nonlinear site response approach, the GQ/H + PWP model, and the DEEPSOIL V.7 program. At multiple layers of boreholes, ru is more than or equal to 0.8, indicating that the Sibalaya liquefaction flow area is still susceptible to liquefaction.
The Governor's Office of West Sulawesi Province is close to an active fault, which triggers its vulnerability to seismic activity. The Mamuju Majene Earthquake destroyed the Governor's office building with a magnitude of Mw 6.2 in 2021. The geological conditions at the site are alluvial deposit formations. In addition to the geotechnical conditions, it has the characteristics of sandy soil with fine to medium gradations. Liquefaction causes a loss of soil strength and an increased pore water pressure caused by vibrations on the earth's surface in the form of seismic waves. It causes a decrease in effective stress, ground settlement, and lateral spreading. This study aims to determine the potential for liquefaction in The Governor's Office of West Sulawesi using a simplified procedure method with a Standard Penetration Test (SPT). The Peak Ground Acceleration (PGA) value is determined using the RSA Human Settlements. The Liquefaction Potential Index (LPI) produces five zones of liquefaction potential levels. The analysis showed that The Governor's Office of West Sulawesi experienced liquefaction at a depth of 12-18 meters with a moderate to very high level.
Underground structures are increasingly used worldwide mainly for transportation and utility services and have become a major component in infrastructure development. Although underground structures are considered safer than above ground structures due to its confinement characteristics, past earthquake events such as Kobe earthquake (1995), Wenchuan earthquake (2008), etc., revealed that tunnels are equally vulnerable under dynamic events. Based on Tohuku, Japan Earthquake (2011), Nepal Earthquake (2015) repeated shaking events (i.e., foreshocks and aftershock occurrences during earthquake) also contributed equally in inducing failures in infra-structures. In India, major portion of tunnel projects were carried out in Northern parts, i.e., Indo-Gangetic plains which contains significant portion of silty sand deposits. In case of dynamic events, the changes in soil saturation in these deposits due to variation in ground water table conditions may results in pore pressure generation and can affect the structural stability of the tunnel system. Considering the above aspects, the present study aims to assess the dynamic behavior of shallow tunnels embedded in partially saturated silty sand bed under repeated shaking events. For this purpose, 1-g shaking table experimental study was conducted on scaled down square tunnel embedded in partially saturated sand bed having 60% relative density with 25% saturation. Incremental repeated shaking events of 0.1 and 0.2 g were applied sequentially, and tunnel-soil interaction behavior was evaluated in terms of acceleration response, developed pore water pressure, pore water pressure ratio, dynamic earth pressure, and displacement of soil, respectively. The displacement of tunnel and strain developed during dynamic events were evaluated using 2D digital image correlation technique. Based on the obtained test results, the factors influencing the dynamic behavior of tunnels in partially saturated ground under repeated incremental shaking events were evaluated and presented.KeywordsTunnel-soil interactionSoil saturationRepeated shaking events2-digital image correlation techniqueLiquefaction
With the increasing demand for renewable harvested energy, the size of the turbine blade keeps on increasing which makes the turbine tower much taller and slender. Owing to the advantage of stable wind velocity and space availability, the offshore wind turbines have become prevalent. Wind turbine tower undergoes various dynamic loading in regular operation such as rotor excitation (1P), vibration due to passing of blade (3P), in addition to wind, storm, wave (in case of offshore) and earthquake. Thus, estimation of natural frequency of a wind turbine is of utmost importance to avoid any frequency matching with the regular excitation, 1P and 3P. In this paper, a transfer matrix-based analytical methodology has been proposed to estimate the natural time period of an offshore wind turbine with a mono-pile foundation. Fluid–structure interaction has been incorporated within the study by using hydrodynamic mass throughout the length of transition piece and monopile, and soil-structure interaction has been considered by providing linear elastic p–y springs throughout the length of monopile. A complete parametric study has been considered which shows the dependency of natural frequency on the various geometric and material properties of both tower and monopile, and the material properties of soil. The natural frequency was found to be significantly affected by soil properties, which shows the importance of soil-structure interaction in the design of offshore structures.KeywordsWind turbineNatural frequencyTransfer matrix
The rainfall in the state of Uttarakhand has a dynamic version. The erratic cloudbursts with unpredictability in rainfall intensity usually cause sudden variation in slope saturation especially during monsoon seasons. This led to frequent rainfall-induced slope failures in past years. Additionally, the region is also categorized under seismic zone IV and V as per the Indian seismic zonation map. When unforeseeable seismic events may associate with these partially saturated slopes, the sudden slope failures can endanger human lives and can affect major infrastructures in these regions. The observed repeated shaking events such as the Japan earthquake (Tohoku) (2011), Nepal earthquake (2015), etc., highlighted the possibility of multiple shaking events and its influence on the infrastructures. Considering the above, this study aims to evaluate the behaviour of the partially saturated slope subjected to repeated dynamic loading conditions. Using 1-g shaking table experiments, the dynamic response of slope was evaluated. For experimental studies, debris material collected from the lower Himalayan region in Uttarakhand was used for model slope preparation for simulating field behaviour. For experimental testing, slope having 45º slope angle with 60% density was prepared using 10% water content for achieving 40% partial saturated conditions. The model slope was then subjected to repeated incremental dynamic loading conditions of 0.1 g, 0.2 g, 0.3 g, and 0.4 g acceleration intensity respectively. To compare the influence of repeated shaking on the slope and its interaction with the adjacent structures, a scaled-down model structure was installed at a 250 mm distance from the crest portion of the slope. The influence of acceleration response, pore pressure generation, soil settlement, and structure displacement were evaluated and compared. In addition to above instrumentation scheme, a 2-D digital image correlation system was additionally used for slope and structural displacement. An attempt also made to model the experiments using FLAC 3D software for estimating the failure conditions. Based on the obtained test results, parameters influencing the stability of partially saturated slope subjected to repeated acceleration loading events have been evaluated, and its influence on the adjacent structure is presented.KeywordsPartially saturated slope2-D digital image correlationSlope failureRepeated dynamic eventsFLAC3D
The objective of the current work is to create a numerical model to assess the dynamic behaviour of earthen embankments built on liquefiable soil. The PLAXIS 2D program, which is based on the finite element approach, was used to create the model. The foundation soil, which is the primary focus of this study, has been modelled using UBC3D-PLM constitutive model while the earth embankment material has been simulated considering the Mohr–Coulomb constitutive model. To calibrate the crucial model parameters, a series of calibration studies have been conducted. The well-calibrated model parameters later have been implemented for simulating a well-documented centrifuge study. The difference in experimental and numerical models has been highlighted. Study reveals that excess pore water pressure near the embankment toe is the main concern of instability of earthen embankment which results in excessive embankment crest settlement. However, soil below embankment crest never reaches initial liquefaction condition and undergoes dilation, which shows the capability of the UBC3D-PLM constitutive model in capturing the shear-induced dilation behaviour. A well comparative study of experimental and numerical analysis can provide us deeper insights into this aspect and which can also highlight key features in order to provide counter mechanism against liquefaction-induced settlement of earthen embankment. Study showed a good agreement in evaluating the effect of liquefaction on the response of earthen embankment.
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