Geotechnical Earthquake Engineering Research Articles

Experimental evaluation of dynamic geotechnical parameters of tailings

The paper is focused on the testing of material from the "Lyulyakovitsa" tailings dam situated in proximity to the town of Panagyurishte in Bulgaria. The primary objective of this study is to investigate various laboratory techniques aimed at determining essential dynamic characteristics of the studied material. This research is conducted with the goal of subsequently assessing the seismic response of the existing tailings dam. In the context of performing an equivalent linear analysis, a widely used approach in geotechnical earthquake engineering, several crucial relationships and parameters come into play. These include the material's stiffness degradation, the damping ratio, and the small-strain stiffness, expressed through the shear wave velocity. The paper describes analysis of three experiments carried out in the geotechnical laboratory "Komaba" at the University of Tokyo. These experiments introduce undrained cyclic triaxial tests conducted under identical relative density (95%) of the tailings and executed at 50 kPa, 80 kPa, and 100 kPa effective confining stress, specifically, respectively. Additionally, two distinct testing methods were employed to measure the shear wave velocity in the specimens. The findings align with certain established directions in the existing literature for characterizing the dynamic properties of granular soils. Simultaneously, they underscore the practicality of the laboratory experiments adopted for acquiring a comprehensive set of relationships and parameters.

Seismically progressive motion mechanism of earth slopes considering shear band porewater pressure feedback under earthquake excitations

The complicated seismic response of earth slopes and the transition mechanism from progressive to catastrophic motion of landslides have long been recognized as one of the most challenging research topics in geotechnical earthquake engineering. In this paper, this fundamental conundrum will be tentatively unveiled from a new perspective combining the seismic slope displacement analysis with (mechanical) dynamic porewater pressure feedback of the shear band soils against the earthquake excitation. We present both the conceptual scheme and the calculation framework to numerically study the dynamic changes of porewater pressure, shear strength parameters, and hydraulic properties of the shear band soils. Their significant influences to the change of earthquake-induced landslide movement modes are systematically investigated. Different dilation angles are chosen to characterize the shear dilation and shear contraction processes in the shear band soil, while the dynamic porewater pressure feedback in the shear band soil during the continuous seismic displacement is investigated. The results show that the seismic slope displacement and failure strongly depend on the mechanical feedback of the shear band soil. When the dilation angle is positive, the porewater pressure feedback in the shear band during the slope movement is negative, and the effective resistance stress increases, which is not susceptible to catastrophic motion. On the other hand, when the dilation angle is negative, the positive porewater pressure feedback may lead to catastrophic failure. At last, the effects of shear softening/hardening combined with dilation angle evolution on the ultimate slope movement mode are also put forward.

EDITORIAL SCOPE: GEOTECHNICAL EARTHQUAKE ENGINEERING EDITION

One of the main civil engineering disciplines is currently the focus area of the Journal of Civil Engineering, Science, and Technology (JCEST): geotechnical and earthquake engineering. We are honoured to present this editorial focusing on the dynamic and evolving field of geotechnical earthquake engineering, with an emphasis on seismic soil-structure interaction (SSI). These studies offer valuable insights into novel design methodologies, materials, and analysis approaches, which are crucial for ensuring the safety and resilience of infrastructure. This editorial paper collected information from the freely-accessible SCOPUS database to identify common keywords used in published papers pertaining to geotechnical earthquake engineering from 2015 to 2023. The analysis reveals that the ‘seismic’ and ‘structure’ terms are the most frequently utilised keyword in articles related to this field. As the editors of our esteemed journal, it is our privilege to shed light on this critical area of research that plays a pivotal role in ensuring the safety and resilience of civil infrastructure subjected to seismic forces.

Preface

The 5th International Conference on Earthquake Engineering and Disaster Mitigation, ICEEDM 2022, was held on 28th-29th September 2022. The 5th ICEEDM in Gadjah Mada University was profoundly enjoying the collaboration with the joint-organizing committee with the Indonesian Earthquake Engineering Association (AARGI), International Association for Earthquake Engineering (IAEE), Japan Association for Earthquake Engineering (JAEE), Bandung Institute of Technology, Indonesian Islamic University, and Atmajaya University. The conference was supported by a scientific committee from four countries and twelve keynote speakers from five countries, i.e., Canada, Indonesia, Japan, Taiwan, and the USA.The 5th ICEEDM 2022 was held to provide an opportunity to share experiences and disseminate the latest research and development results related to earthquake engineering, which will be very useful for increasing knowledge and disaster mitigation policies. It is hoped that this conference will benefit all parties to minimize the risk of earthquake hazards in Indonesia and worldwide.The 5th ICEEDM 2022 proceeding contains papers written by academics, professionals, researchers, and students from Indonesia and Japan. Various research works related to the conference theme were presented during the conference. A total of 41 full papers accepted upon review for the proceeding publication are categorized into the following topics: A. Structural Engineering, including; Structural Earthquake Engineering, Structural Dynamics, Performance-Based Design and Evaluation, Structural Assessment and Retrofit, Seismic Devices and Applications, Non-engineered Buildings, Experimental & Numerical Modelling B. Geotechnical Engineering, including; Geotechnical Earthquake Engineering, Soil-Structure Interaction C. Seismological Engineering, including; Seismic Micro-zonation, Case Histories in Recent Earthquakes, D. Disaster Mitigation, including; Seismic Hazard and Tsunami Disaster Mitigation, Early Warning System, Post Disaster Recovery and Reconstruction, Community-Based Disaster Risk Reduction & Management

Determination of Empirical Correlations between Shear Wave Velocity and Penetration Resistance in the Canakkale Residential Area (Turkey)

One of the most important parameters used to determine the dynamic properties of soil layers is the shear wave velocity. In geotechnical earthquake engineering, the shear wave velocity is used to determine the shear modulus, which provides the input parameters for the design of earthquake-resistant structures. Although there are measurement methods used in field studies to determine the shear wave velocity, they may not be economical in some cases. In this study, the empirical correlations between the shear wave velocity and penetration resistance in sandy soils were investigated with the use of geotechnical and geoseismic data obtained within the scope of microzonation studies performed in the Canakkale residential area. The results of the study were compared with correlations obtained from previous studies, and the equation we produced showed a good ability to predict the shear wave velocity. In addition, it was determined that standard penetration resistance, without energy correction, provided a better correlation coefficient.

A novel peridynamic solution for modelling saturated soil-pore fluid interaction in liquefaction analysis

Saturated soil-pore fluid interaction under earthquake shaking can cause extensive damages to critical infrastructure systems. As such, accurate modeling of saturated soil-pore fluid interaction and its consequences (e.g., seismically-induced large deformation) are of particular importance for liquefaction analysis. Peridynamics (PD) has emerged as an effective method for solving large deformation problems by overcoming the disadvantage of finite element method caused by mesh dependency. However, the PD has not been extended to model soil-pore fluid interaction, limiting its application in liquefaction analysis. To bridge this gap, a novel solution strategy is presented for modeling soil-pore fluid interaction (i.e., the u-p equations herein) in liquefaction analysis of saturated granular soils, based on a hybrid PD (HPD) method recently proposed by the authors and co-workers. An explicit-explicit method is used to solve the coupled u-p equations. Liquefiable soil on level and sloped ground are analyzed and compared with experimental data and finite element simulations to validate availability and efficiency of the method, demonstrating the method to be effective in solving the soil-pore fluid equations and applicable to a broad range of geotechnical earthquake engineering problems associated with liquefaction.

Framework of a performance-based design for liquefaction resistance

Seismic liquefaction hazards remain a very challenging problem in geotechnical earthquake engineering and are one of the most important aspects currently to update the framework of the liquefaction resistance design from a performance-based perspective. In this paper, by investigating the characteristics of the seismic liquefaction hazard, as well as integrating the existing performance-based earthquake engineering (PBDEE) and advanced risk management theory, the connotation and key points of performance-based liquefaction hazard governance are proposed, and the framework of a performance-based design for liquefaction resistance (PBDLR) is constructed according to the technical system construction rules. The results indicate that the liquefaction hazard has its own characteristics in terms of the hitting target, hazard scale, occurrence mechanism, chain effect, treatment technology, and uncertainty of the influencing factors. Its technical system of hazard governance requires special consideration. The presented PBDLR integrates the advantages of both the advanced risk management theory and the existing performance-based earthquake engineering technology system, and the elements and structure consider the sociality of the target, the integrity of the function, the hierarchy of the composition, and the linkage of the elements and the completeness of the technology. The PBDLR takes the liquefaction hazard governance objective as the primary factor and performance analysis as the technical main body of the framework, and it is equipped with several new elements matching the characteristics of the liquefaction hazard and the requirements for the technical development of an anti-liquefaction design. The PBDLR presented in this paper can provide guidance and a reference for future research and technical development in liquefaction hazard governance.

Resonant Column Testing Procedure for Microbial-Induced Carbonate-Precipitated Sands

Abstract One of the fundamental inputs to site response analysis is the characterization of the dynamic properties of the soil, namely the shear modulus and material damping ratio. Because of soil’s nonlinear behavior, these properties change with induced shear strains, and modulus reduction and damping (MRD) curves have been proposed to capture that cyclic shear strain dependency. Microbial-induced carbonate precipitation (MICP) is a natural cementation process that induces the precipitation of calcium carbonate, bonding soil particles together. Laboratory experiments have demonstrated that MICP can improve the mechanical behavior of soils and mitigate their liquefaction potential. However, MRD curves have not been developed for MICP-treated soils, which hinders further evaluations of their suitability as a ground improvement technique for geotechnical earthquake engineering applications. To the best of our knowledge, this paper provides the first empirical study measuring the shear strain–dependent dynamic properties of MICP-treated sands for different cementation levels (i.e., lightly to heavily cemented). Outcomes from this work include empirical models of the maximum shear modulus and minimum shear strain damping ratio of MICP-treated clean sands and the corresponding mean MRD curves. The experimental program includes MICP-treated specimens of Ottawa 20-30 sand tested with a resonant column (RC) device incorporating a modified RC porous disk that (1) minimizes the disturbance between treatment and installation of MICP-treated samples prior to being tested in the RC device, (2) prevents slippage between the specimen and the modified RC porous disk during RC shearing, and (3) enables repeatability of the MICP-treated sample preparation. We find that the level of cementation influences the MRD curves of MICP-treated sands. Linear elastic and volumetric shear strain thresholds for MICP-treated sands are smaller than those for untreated sands, whereas the initial shear modulus for treated soils is larger than its counterpart for untreated sands.

A stepwise artificial boundary condition for wave propagation in elasto-plastic media

Wave propagation in elasto-plastic media is often encountered in earthquake geotechnical engineering. However, dynamic boundary conditions in the numerical simulation of wave propagation problems are often developed based on linear elastic assumptions. In this study, the method of characteristics is utilized to propose a novel stepwise artificial boundary condition (S-ABC) for wave propagation in elasto-plastic media. The numerical implementation of S-ABC within a finite element procedure in time domain is developed. Typical numerical examples are chosen to verify the efficiency of this ABC, including: 1) a semi-infinite soil column model subjected to impulse load, where the influence of unloading wave front in elasto-plastic media is discussed; 2) an infinite and a finite soil column model under cyclic seismic wave input, where the proposed S-ABC is compared with the traditional viscoelastic artificial boundary condition (V-ABC). Numerical results demonstrate the significantly higher accuracy and robustness of the proposed S-ABC for nonlinear and elasto-plastic media compared to traditional V-ABC. The influence of unloading wave front on artificial boundary condition for elasto-plastic media is also revealed, which has not been reported previously.

Summary of geotechnical activities in response to the 2011 Tohoku earthquake; follow-up of my TC203 Ishihara Lecture in 2019

The devastating earthquake in Tohoku Region of Japan in 2011 caused many geotechnical problems and the recovery from them was an unforgettable experience. This paper describes first the seismological background of that extreme event whose return period was longer than 1000 years, producing unprepared situation among people. The geotechnical effect of this earthquake consists mainly of collapse of sea walls due to overtopping of tsunami water and liquefaction-induced damage of levees and residential lands, while landslide was fortunately of minor scale. Much efforts were made after the earthquake on establishing hazard assessment methodology for residential land and ground improvement under existing houses. The recovery from the nuclear incident is still going on. These issues were presented during the 2019 Ishihara Lecture during the seventh International Conference on Geotechnical Earthquake Engineering in Rome organized by the Technical Committee 203 of the International Society for Soil Mechanics and Geotechnical Engineering and were published in the conference proceedings. However, there is a tradition that every Ishihara Lecture has been published in this International Journal of Soil Dynamics and Earthquake Engineering. In view of this, the original publication was totally rewritten and new information was added so that a second publication might be possible as a follow-up.

A fully explicit staggered algorithm for near‐field wave propagation of fluid‐saturated porous media based on u‐p dynamic formulation

AbstractNear‐field wave propagation of the fluid‐saturated porous media (FSPM) is an important issue in soil dynamics and geotechnical earthquake engineering. In the current study, a fully explicit staggered algorithm for the near‐field wave propagation analysis of the FSPM in the time domain is developed based on the u‐p dynamic formulation. The decoupling of dynamic formulation is implemented by the diagonalization of the mass matrix and pore fluid compressibility matrix. The central difference method and Newmark constant average acceleration method are used for the solution of the displacement and velocity of solid skeleton, and the backward difference method is used for the solution of pore fluid pressure in the time domain. The effectiveness and feasibility of the matrix diagonalization are verified by the comparison with the classical numerical algorithm. The proposed algorithm is also validated by the comparison of the numerical results with the corresponding analytical solution results. Combing with the transmitting artificial boundary condition, the proposed algorithm is then applied to investigate the seismic response of a FSPM free field, and its applicability to the typical near‐field wave propagation problems of the FSPM is indicated. The stability analysis of the proposed algorithm is finally conducted, and the corresponding stability criterion is presented. For the proposed algorithm, all the dynamic variables of the FSPM are solved in an iterative way and the coupling dynamic equations need not to be solved at each time step. The computational effort can be reduced considerably, and the computational efficiency can be improved remarkably.

Verification of a System for Sustainable Research on Earthquake-Induced Soil Liquefaction in 1-g Environments

Within the presented research, model tests were performed in 1-g conditions to investigate the liquefaction potential of Skopje sand as a representative soil from the Vardar River’s terraces in N. Macedonia. A series of shaking table tests were performed on a fully saturated, homogeneous model of Skopje sand in the newly designed and constructed laminar container in the Institute of Earthquake Engineering and Engineering Seismology (IZIIS), Skopje, N. Macedonia. The liquefaction depth in each shaking test was estimated based on the measured acceleration and pore water pressure as well as the frame movements of the laminar container. The surface settlement measurements indicated that the relative density increased by ~12% after each test. The observations from the tests confirmed that liquefaction was initiated along the depth at approximately the same time. The number of cycles required for liquefaction increased as the relative density increased. As the pore water pressure rose and reached the value of the effective stresses, the acceleration decreased, thus the period of the soil started to elongate. The results showed that the investigated Skopje sand was highly sensitive to void parameters and, under specific stress conditions, the liquefaction that occurred could be associated with large deformations. The presented experimental setup and soil material represent a well-proven example of a facility for continuous and sustainable research in earthquake geotechnical engineering.

Analytical 1D transfer functions for layered soils

Transfer functions are constantly used in both Seismology and Geotechnical Earthquake Engineering to relate seismic ground motion at different depths within strata. In the context of diffusive theory, they also appear in the expression of the imaginary part of 1D Green’s functions. In spite of their remarkable importance, their mathematical structure is not fully understood yet, except in the simplest cases of two or three layers at most. This incomplete understanding, in particular as to the effect of increasing number of layers, hinders progress in some areas, as researchers have to resort to expensive and less conclusive numerical parametric studies. This text presents the general form of transfer functions for any number of layers, overcoming the above issues. The mathematical structure of these transfer functions comes defined as a superposition of independent harmonics, whose number, amplitudes and periods we fully characterize in terms of the properties of the layers in closed-form. Owing to the formal connection between seismic wave propagation and other phenomena that, in essence, represent different instances of wave propagation in a linear-elastic medium, we have extended the results derived elsewhere, in the context of longitudinal wave propagation in modular rods, to seismic response of stratified sites. The ability to express the reciprocal of transfer functions as a superposition of independent harmonics enables new analytical approaches to assess the effect of each layer over the overall response. The knowledge of the general closed-form expression of the transfer functions allows to analytically characterize the long-wavelength asymptotics of the horizontal-to-vertical spectral ratio for any number of layers.

Evaluation of Liquefaction Properties of East Coast Sand of New Zealand Mixed with Varied Kaolinite Contents Using the Dynamically Induced Porewater Pressure Characteristics

In earthquake geotechnical engineering, physical model experiments have proven to be significant and valuable in understanding the complex physics and engineering behaviors of prototype undrained soils in fields. An executed literature review indicated that large-scale physical model testing, such as shaking table (ST) and centrifuge devices, have associated advantages and limitations. The current paper presents the design, fabrication, and calibration of a 600N-capacity, small-scale, one-directional (1-D) laboratory ST device that enables quick and valuable assessment of soil liquefaction mechanisms. The dynamically induced porewater pressure (PWP) generation characteristics of sand soil mixed with different percentage weights of clay were evaluated and illustrated as a case study for testing the ST device’s performance. The east coast sand (ECS) of New Zealand’s North Island was mixed with different percentages of kaolinite clay to produce five variants of ECS (00, 05, 10, 20, 25, and 30). Three input sine wave ground motions of a constant frequency of 10 Hz and amplitudes of 2, 3, and 4 were applied and classified in the current study as low, intermediate, and moderate ground motions, respectively, to evaluate the evolution of the dynamic excess pore pressures in the soil samples. The results indicated that the clean ECS and mixed samples with lower clay content (ECS00, ECS05, ECS10, and ECS15) produced the highest excess PWP throughout the three shaking cycles, with higher tendencies of contraction and liquefaction properties. On the other hand, soil samples with a higher percentage of clay (ECS20 and ECS20) yielded the lowest PWP, with softening and dilative properties.

Application of Soil Moisture Active Passive (SMAP) Satellite Data in Seismic Response Assessment

The proven relationship between soil moisture and seismic ground response highlights the need for a tool to track the Earth’s surface soil moisture before and after seismic events. This paper introduces the application of Soil Moisture Active Passive (SMAP) satellite data for global soil moisture measurement during earthquakes and consequent events. An approach is presented to study areas that experienced high level of increase in soil moisture during eleven earthquakes. Two ancillary datasets, Global Precipitation Measurement (GPM) and Global Land Data Assimilation (GLDAS), were used to isolate areas that had an earthquake-induced increase in soil moisture from those that were due to hydrological processes. SMAP-based soil moisture changes were synthesized with seismic records developed by the United States Geological Survey (USGS), mapped ground failures in reconnaissance reports, and surface changes marked by Synthetic Aperture Radar (SAR)-based damage proxy maps. In the majority of the target earthquakes, including Croatia 2020, Greece 2020, Indonesia 2018, Taiwan 2016, Ecuador 2016, and Nepal 2015, a relationship between the SMAP soil moisture estimates and seismic events was evident. For these events, the earthquake-induced soil moisture response occurred in liquefaction-prone seismic zones. The New Zealand 2016 event was the only study region for which there was a clear inconsistency between ΔSMSMAP and the seismic records. The promising relationship between soil moisture changes and ground deformations indicates that SMAP would be a useful data resource for geotechnical earthquake engineering applications and reconnaissance efforts.

Geostatistical Framework for Estimation of VS30 in Data-Scarce Regions

ABSTRACTThe time-averaged shear-wave velocity in the upper 30 m (VS30) is widely used as a proxy for site characterization in building codes. Regional estimations of VS30 often use either slope-based, terrain-based, or geological approaches as a proxy. This technique has proven useful at a number of locations globally, and slope-based estimates formed the basis of the original global VS30 model implemented by the U.S. Geological Survey. Geostatistical models involve the study of potentially spatially correlated parameters. Modeling challenges arise when parameters are scarce or uncertain, and traditional geostatistical workflows cannot be implemented in all settings. In this study, the benefits of the spatial extents of VS30 proxies are used to supplement local data to implement a methodology for improving estimates using a multi-Gaussian Bayesian updating framework. This methodology is presented in the context of a data-scarce region, specifically, the Kathmandu Valley in Nepal. Using geostatistical approaches typically used by the petroleum industry, this article develops a novel practice-oriented framework for VS30 estimation that can be adapted for use on a region-by-region basis. This framework provides an informed estimate and assessment of the uncertainties in which quantification of VS30 is required in geotechnical earthquake engineering applications.

On the Interpretation of Conditional Ground-Motion Models

ABSTRACT Recently, a number of conditional ground-motion models (CGMMs) have been developed for intensity measures (IMs) other than pseudospectral acceleration (PSA) values that are particularly useful for geotechnical earthquake engineering problems. In a CGMM, a non-PSA IM is conditioned on PSA IMs, and other earthquake parameters (e.g., magnitude Mw, rupture distance Rrup) as well as site conditions (e.g., the time-averaged shear-wave velocity in the top 30 m VS30). Even though CGMMs are useful in engineering practice, their interpretation in the context of traditional (non-CGMM) has not been discussed to the authors’ best knowledge. In this study, we provide an interpretation of CGMMs in terms of the scaling difference between the spectral and nonspectral IMs used in the formulation of a CGMM and the coefficient of correlation of these spectral and nonspectral IMs. In addition, the interpretation can derive into an alternative procedure for calculating correlation coefficients between PSA IMs and non-PSA IMs, which is illustrated.

Effects of spatial variability of soil properties and ground motion characteristics on permanent displacements of slopes

The seismic performance of earth slopes is a problem of great importance in geotechnical earthquake engineering associated with various sources of uncertainty. This research investigates the effects of two important causes of such uncertainty: (a) the spatial variability of soil properties and (b) the variability of the temporal and frequency characteristics of the earthquake excitation. The former is investigated based on a series of detailed dynamic numerical simulations using stationary random fields of both cross-correlated and spatially autocorrelated soil properties. The latter is explored by conducting incremental dynamic analysis at various levels of excitation intensity using (a) a total of forty historic earthquake and synthetic records, modified to match the Eurocode 8 design spectra for rock sites, and (b) thirty original historic earthquake records. The results demonstrate the significant effect of the spatial variability of soil properties on the permanent slope displacements. Moreover, they show that the effect of the uncertainty associated with the variability in the temporal and frequency characteristics of excitations is more important compared to the effect of the spatial variability of soil properties.

Mapping of the liquefaction index, case study

Abstract The present work uses a number of empirical models from geotechnical earthquake engineering (CPT-based liquefaction models) in combination with some geostatistics tools to assess the soil liquefaction potential over an extended area at the Airport of Algiers (Algeria), by the kriging approach. The SIG software program along with variograms and the kriging method were all applied together for the purpose of modeling the variation of the liquefaction potential (PL) against liquefaction in the region under study. This approach allowed determining the missing data in that region. This geostatistical method helped to draw maps at different soil depths. The results obtained revealed that the models developed were potentially capable of accurately estimating the needed data. This study made it possible to determine a number of parametric quantities that support the empirical correlation between the liquefaction potential index and liquefaction. The results show that the higher the standard deviation, the greater the uncertainty.

A review of near-surface QS estimation methods using active and passive sources

Seismic attenuation and the associated quality factor (Q) have long been studied in various sub-disciplines of seismology, ranging from observational and engineering seismology to near-surface geophysics and soil/rock dynamics with particular emphasis on geotechnical earthquake engineering and engineering seismology. Within the broader framework of seismic site characterization, various experimental techniques have been adopted over the years to measure the near-surface shear-wave quality factor (QS). Common methods include active- and passive-source recording techniques performed at the free surface of soil deposits and within boreholes, as well as laboratory tests. This paper intends to provide an in-depth review of what Q is and, in particular, how QS is estimated in the current practice. After motivating the importance of this parameter in seismology, we proceed by recalling various theoretical definitions of Q and its measurement through laboratory tests, considering various deformation modes, most notably QP and QS. We next provide a review of the literature on QS estimation methods that use data from surface and borehole sensor recordings. We distinguish between active- and passive-source approaches, along with their pros and cons, as well as the state-of-the-practice and state-of-the-art. Finally, we summarize the phenomena associated with the high-frequency shear-wave attenuation factor (kappa) and its relation to Q, as well as other lesser-known attenuation parameters.