Soil Liquefaction Research Articles

End of the Cretaceous

Abstract The Cretaceous ended when the Chicxulub asteroid struck the Yucatán platform, and all deposits and landforms generated are earliest Paleocene in age. Drill core from the Cretaceous–Paleogene (K–Pg) boundary sequence deposited on top of the Chicxulub impact structure's peak ring paired with geophysical data within the crater and other well-preserved marine and terrestrial K–Pg boundary sites provide insight into impact processes and effects on Earth's ecosystems, in terms of extinction and recovery. Key findings as reviewed here are: (1) the confirmation of acoustic fluidization as a physical principle to explain impact structure formation; (2) the importance of the target rock properties and marine setting for impactite depositional processes and drivers of climate change; (3) the state of understanding of extinction mechanisms and ecological recovery; and (4) implications for impact-generated hydrothermal habitat creation. Areas highlighted for the next stages of discovery include: (1) physics and chemistry of impact vapour plumes and ejecta processes; (2) sampling of the K–Pg boundary deposit and impact melt sheet within the central basin of the impact structure; (3) examination of ecosystem recovery in an ‘Early Ocean’ scenario at a range of K–Pg boundary sites; and (4) experiments and observations of impact hydrothermal systems as habitats on Earth and other worlds.

Accurate and generalizable soil liquefaction prediction model based on the CatBoost algorithm

Accurate and generalizable soil liquefaction prediction model based on the CatBoost algorithm

Microbial nitrogen bubble formation in porous media

Microbially induced nitrogen (N2) gas bubbles can desaturate subsurface areas and thus have been considered as an alternative ground improvement technique for mitigating soil liquefaction potential caused by earthquakes. However, the detailed mechanisms of subsurface N2 bubbles are not well understood and remain a subject of ongoing research. In this study, a transparent microfluidic device was utilized to mimic biological N2 gas bubble formation by nitrate-reducing bacteria and to visually characterize the entire process. During N2 gas formation, a limited number of bubble nucleation sites were identified, which gradually expanded upward through the preferential pore channels. N2 gas bubbles tended to create interconnected gas pockets rather than existing as evenly distributed small gas cavities. The degree of water saturation gradually reduced over a week as the bubbles were produced. The gas ganglia repeatedly grew until they reached the top boundary, which triggered a drastic expulsion of bubbles by ebullition. Despite fluctuations in saturation level, the residual saturation was maintained at around 73 %. Comparative experimental case studies of CO2 gas bubble formation were conducted to identify contrasting gas formation mechanisms. CO2 gas bubbles were generated via the abiotic decompression of a supersaturated CO2 solution under two distinct rates of pressure reduction. Rapid CO2 bubble formation led to uniform nucleation and 41 % residual saturation, while slower formation yielded 35 % due to stable liquid displacement by the gas front. This study highlights the potential of the microfluidic device as an experimental tool for visualizing subsurface gas formation mechanisms. The insights gained could further enhance and optimize geotechnical applications involving gas formation in highly saturated soils.

Induced Partial Saturation: From Mechanical Principles to Engineering Design of an Innovative and Eco-Friendly Countermeasure against Earthquake-Induced Soil Liquefaction

Earthquake-induced soil liquefaction is a catastrophic phenomenon that can damage existing building foundations and other structures, resulting in significant economic losses. Traditional mitigation techniques against liquefaction present critical aspects, such as high construction costs, impact on surrounding infrastructure and effects on the surrounding environment. Therefore, research is ongoing in order to develop new approaches and technologies suitable to mitigate liquefaction risk. Among the innovative countermeasures against liquefaction, Induced Partial Saturation (IPS) is considered one of the most promising technologies. It consists of introducing gas/air bubbles into the pore water of sandy soils in order to increase the compressibility of the fluid phase and then enhance liquefaction resistance. IPS is economical, eco-friendly and suitable for urbanised areas, where the need to reduce the risk of liquefaction must be addressed, taking into account the integrity of existing buildings. However, IPS is still far from being a routine technology since more aspects should be better understood. The main aim of this review is to raise some important questions and encourage further research and discussions on this topic. The review first analyses and discusses the effects of air/gas bubbles on the cyclic behaviour of sandy soils, focusing on the soil volume element scale and then extending the considerations to the real scale. The use of useful design charts is also described. Moreover, a section will be devoted to the effect of IPS under shallow foundations. The readers will fully understand the research trend of IPS liquefaction mitigation and will be encouraged to further explore new practical aspects to overcome the application difficulties and contribute to spreading the use of this technology.

Recent Jishishan earthquake ripple hazard provides a new explanation for the destruction of the prehistoric Lajia Settlement 4000a B.P.

The Jishishan Ms 6.2 earthquake occurred at 23:59 on December 18, 2023 in Gansu Province, China. We conducted a field survey to assess the hazards and damages caused by the earthquake and its associated geo-activities. Subsequently, we organized a seminar to discuss the possible causes of the destruction of a prehistoric site—Lajia Settlement—dated back to four thousand years B.P. and located only several kilometers away from the epicenter of the Jishishan earthquake. The Jishishan earthquake was unique for its hazard and disaster process, which featured ground shaking and a series of complex geological and geomorphological activities: sediment and soil spray piles, liquefaction, collapse, landslide, and mudflow along water channels. We define this phenomenon as the Jishishan earthquake ripple hazard (JERH). The most recent evidence from the JERH suggests that a prehistoric earthquake similar to the JERH, instead of riverine floods or earthquake-induced landslide dam outburst flood, as previously hypothesized, destroyed the Lajia Settlement.

A probabilistic extension of existing site-specific liquefaction triggering and liquefaction manifestation methods for regional scale evaluations

Liquefaction hazard analyses are needed for regional-scale applications, such as risk analysis and upgrades of electrical transmission, water conveyance, and highway systems. In this paper, we expand well-established site-specific liquefaction triggering and manifestation analysis methods for regional scale application by explicitly addressing the uncertainty in groundwater conditions, soil behavior classification, and cyclic resistance. The uncertainty inherent to regional-scale geotechnical properties is quantified by considering the inputs into conventional liquefaction triggering and manifestation analyses as random variables. With this flexible and extensional formulation, the geostatistical properties needed for regional scale analyses may be estimated by either averaging borehole information or spatially interpolating geotechnical properties across broad geologic deposits. We demonstrate the utility of the method by analyzing the liquefaction hazard throughout the south San Francisco Bay area, California, U.S.A. The resulting estimates of the probability of liquefaction manifestation tend to be lower than previously published estimates, largely owing to the geologic structure of the area and the uncertainty in liquefaction surface manifestation once liquefaction is triggered at depth. Uncertainties in groundwater conditions, soil behavior classification, penetration resistance, and liquefaction manifestation are quantified by the regional scale analyses, which provide a complete and systematic evaluation of the liquefaction hazards, localize the uncertainties in subsurface conditions, and facilitate supplemental investigations at areas of high uncertainty to fill data gaps.

A Simplified Model to Predict the Repeated Shear Strain during the Cyclic Triaxial Test by Using an Elastic Coefficient-Damping Ratio System

Some researchers in past years have tried to develop a simplified method for analyzing soil liquefaction. However, the correctness of the pore water pressure in the model will affect the results. In addition, the formulas derived are not easy, and the exact parameters of the model are difficult to obtain. This study used a mass-spring-damping system to simulate the repeated strain of liquefaction cyclic triaxial tests. Because the model is simple and the parameters are easy to understand and obtain, it also shows the extensibility of this model. During the parameter study, damping coefficient c and spring coefficient k parameters decreased with the increasing cyclic number. Preliminary results of the research show that this model can further simulate the repeated strain obtained by cyclic triaxial tests without considering the variation of effective stress during cyclic loading. Four samples were used to verify the model’s correctness, and their boring sites were found in Yunlin areas, Taiwan. Simulation results show that the spring-damping system is feasible for simulated cyclic triaxial tests because the simulated results correlate to the testing results in trend. Generally, the first cycle number simulation will be less accurate because the pore water pressure of the specimen changes rapidly when the performance has just started. In contrast, the increase in subsequent cycles may be biased due to cyclic stress variation and soil plasticity during simulation. In the future, pure sand specimens created in the laboratory will be suggested for simulation.

Investigating a hybrid extreme learning machine coupled with Dingo Optimization Algorithm for modeling liquefaction triggering in sand-silt mixtures

Liquefaction is a devastating consequence of earthquakes that occurs in loose, saturated soil deposits, resulting in catastrophic ground failure. Accurate prediction of such geotechnical parameter is crucial for mitigating hazards, assessing risks, and advancing geotechnical engineering. This study introduces a novel predictive model that combines Extreme Learning Machine (ELM) with Dingo Optimization Algorithm (DOA) to estimate strain energy-based liquefaction resistance. The hybrid model (ELM-DOA) is compared with the classical ELM, Adaptive Neuro-Fuzzy Inference System with Fuzzy C-Means (ANFIS-FCM model), and Sub-clustering (ANFIS-Sub model). Also, two data pre-processing scenarios are employed, namely traditional linear and non-linear normalization. The results demonstrate that non-linear normalization significantly enhances the prediction performance of all models by approximately 25% compared to linear normalization. Furthermore, the ELM-DOA model achieves the most accurate predictions, exhibiting the lowest root mean square error (484.286 J/m3), mean absolute percentage error (24.900%), mean absolute error (404.416 J/m3), and the highest correlation of determination (0.935). Additionally, a Graphical User Interface (GUI) has been developed, specifically tailored for the ELM-DOA model, to assist engineers and researchers in maximizing the utilization of this predictive model. The GUI provides a user-friendly platform for easy input of data and accessing the model's predictions, enhancing its practical applicability. Overall, the results strongly support the proposed hybrid model with GUI serving as an effective tool for assessing soil liquefaction resistance in geotechnical engineering, aiding in predicting and mitigating liquefaction hazards.

Liquefaction at two petrochemical facilities during the February 6, 2023, Kahramanmaras-Turkiye earthquake sequence

Two petrochemical facilities, located in the Dortyol district of Hatay metropolitan city along the Mediterranean coastline in Turkiye were shaken by the February 6, 2023, M7.8 Pazarcik and M7.6 Ekinözü-Elbistan earthquakes in Kahramanmaraş. This study investigates their seismic performances from a seismic soil liquefaction engineering perspective, addressing several key aspects: the i) identification of surface manifestations of seismic soil liquefaction, including soil ejecta, ground deformations, and displacements, ii) examination of subsurface soil characteristics, iii) evaluations of soil liquefaction susceptibility and triggering, iv) analyses of post-liquefaction ground settlements, lateral deformations, and displacements, and v) comparisons of these observed outcomes with predicted results. The assessment results indicated that liquefaction triggering evaluations, based on the SPT- and CPT-based semi-empirical methods of Cetin et al. (2018) and Moss et al. (2006), respectively, were consistent with observed field manifestations of liquefaction or their absence. However, estimated settlements obtained from the liquefaction-induced volumetric settlement procedures of Tokimatsu and Seed (1984), Shamoto et al. (1998) and Cetin et al. (2009), underestimated field settlements. This underestimation was partially explained by the additional contribution of lateral spreading deformations to field settlements, which were not considered due to one-dimensional nature of these volumetric settlement assessments. Additionally, semi-empirical correlations of Hamada et al. (1986) and Youd et al. (2002) consistently overestimated observed lateral displacements. The discrepancies in settlement and lateral spreading displacements are believed to stem from the presence of liquefaction susceptible fine-grained and/or gravelly units, which may have higher residual shear strengths and/or produce higher volumetric strains than typical clean sand layers in case history sites used for developing these semi-empirical methods. The documented field performances and assessment results are hoped to contribute to further developing and refining/calibrating increasingly accurate and reliable empirical and/or analytical methods for assessing hazards related to liquefaction triggering, and liquefaction-induced ground deformations and displacements.

Liquefaction ground deformations and cascading coastal flood hazard in the 2023 Kahramanmaraş earthquake sequence

The 2023 Kahramanmaraş earthquake sequence produced extensive liquefaction-induced ground deformations and ongoing flooding along the shoreline of the Mediterranean port city of İskenderun, Türkiye. This study compiles field observations and analyses from cross-disciplinary perspectives to investigate whether earthquake-induced liquefaction was a significant factor for increasing the flood hazard in İskenderun. Geotechnical reconnaissance observations following the earthquakes included seaward lateral spreading, settlement beneath buildings, and failures of coastal infrastructure. Three presented lateral spreading case histories indicate consistent ground deformation patterns with areas of reclaimed land. Persistent scatterer interferometry (PSI) measurements from synthetic aperture radar (SAR) imagery identify a noticeably greater rate of pre- and post-earthquake subsidence within the İskenderun coastal and urban areas relative to the surrounding regions. The PSI measurements also indicate subsidence rates accelerated following the earthquakes and were typically highest near the observed liquefaction manifestations. These evaluations suggest that while the liquefaction of coastal reclaimed fill caused significant ground deformations in the shoreline area, ongoing subsidence of İskenderun and other factors likely also exacerbated the flood hazard. Insights from this work suggest the importance of evaluating multi-hazard liquefaction and flood consequences for enhancing the resilience of coastal cities.

Bibliometric analysis of artificial intelligence techniques for predicting soil liquefaction: insights and MCDM evaluation

Bibliometric analysis of artificial intelligence techniques for predicting soil liquefaction: insights and MCDM evaluation

Influence of clay content on repeated liquefaction resistance of sand using element test

Soil liquefaction is a major concern because of its potential to cause building collapse, roadbed settlement, and sand eruptions. Field investigations have shown that clayey sand, when liquefied during mainshock, may undergo multiple liquefaction events during the subsequent aftershocks. Although previous research has primarily focused on the initial liquefaction event in clayey sand, research on the mechanism responsible for repeated liquefaction is limited. Consequently, a series of cyclic triaxial experiments are conducted on sand with varying clay contents, and these samples are subjected to various earthquake sequences. The primary objective of this study is to evaluate the cyclic behavior of sandy soil with clay content and analyze its repeated liquefaction resistance under different load sequences. A comprehensive assessment is conducted to understand the evolution of the repeated liquefaction resistance. The test results indicate that clayey sand exhibits the lowest liquefaction resistance during the second liquefaction event. Repeated liquefaction is dominated by stress-induced anisotropy at earlier events and relative density at the final events.

The impact of initial fabric anisotropy on cyclic liquefaction behavior with polygonal particles using the discrete element method (DEM)

Liquefaction is one of the most significant phenomena that can occur in soil during an earthquake. The destructive effects of this phenomenon on earth structures have captured the attention of many geotechnical engineers. Additionally, the gradual increase in pore water pressure during the cyclic loading induced by the propagation of earthquake waves, known as cyclic liquefaction, is a crucial factor that might lead to the complete loss of shear strength in soils. A better understanding of cyclic liquefaction is essential for improving earthquake hazard analysis and mitigating structural damage. Factors influencing liquefaction behavior include particle size, particle grading, and soil fabric. By “soil fabric,” we refer to the arrangement and positioning of particles with each other, particle shape, and the shape of voids among particles. This research aims to focus on the effects of fabric anisotropy on cyclic liquefaction of granular soils with angular particles. To carry out this investigation, the discrete element method has been employed. In the discrete element method, the geometry of particles and, generally, the soil fabric can be considered. In this research, specimens with varying particle orientation angles were produced and subjected to cyclic loading tests under undrained conditions. By examining the stress paths of specimens during cyclic loading, it is observed that the initial fabric and inherent anisotropy significantly influence the behavior of the specimens. Inherent anisotropy leads to varying numbers of cycles required for the initial liquefaction of each specimen. Furthermore, it is observed that as the particle orientation angle increases, the localization of axial strains shifts from tensile to compressive directions. The effect of inherent anisotropy plays a substantial role in the initial liquefaction (ru = 1). If the liquefaction of specimens is of interest at lower values of ru, the effect of inherent anisotropy can be disregarded.

A comparative analysis of ensemble learning algorithms with hyperparameter optimization for soil liquefaction prediction

A comparative analysis of ensemble learning algorithms with hyperparameter optimization for soil liquefaction prediction

Energy-Based Assessment of Liquefaction Behavior of a Non-Plastic Silt Based on Cyclic Triaxial Tests

Earthquakes cause cyclic shear deformations in soil and build-up of excessive pore water pressure as a result of undrained loading, accompanied with rearrangement of soil particles and degradation in stiffness of the soil due to decrease in effective stresses. During loading, the onset of soil liquefaction is defined as a stress state in which the excess pore water pressure is equalized to the total stress. From this point of view, assessment of the pore water pressure development pattern under cyclic loading has been one of the most salient research topics in geotechnical and earthquake engineering. In this study, results of a series of cyclic triaxial tests on non-plastic silt specimens consolidated under 100 kPa effective isotropic consolidation pressure were used to question the modelling ability of pore pressure development models previously proposed for sands. Tests were performed on specimens of 6 different initial relative densities (Dr) ranging between 30-80% and 10 different cyclic stress ratios (CSR). The key parameters of pore water pressure development and shear deformation in the energy-based model used are relative density, cyclic stress ratio and number of cycles. The results revealed that, these energy-based models have a strong potential in evaluation of pore water pressure development pattern of non-plastic silts. Test results also show that the increase in relative density and decrease in CSR causes a ladderlike behavior among pore water pressure and cyclic shear strain, which is relevantly rendered by energy-based models.

Assessing seismic soil liquefaction susceptibility and hazard zonation in Bihar, India: a comparative study of deterministic method

Assessing seismic soil liquefaction susceptibility and hazard zonation in Bihar, India: a comparative study of deterministic method

Geotechnical assessment of seismicity and liquefaction potential at the Banarli landfill in Tekirdag, Turkey

This study, conducted in the Banarli district of Tekirdag Province, Turkey, focuses on soil reaction analysis and liquefaction potential in an area where a landfill and an associated power plant are planned. The research was examined with a one-dimensional ground response analysis to understand seismic behaviour, revealing the varied responses of soil categories to seismic waves. Soft soil layers were found to lengthen the dominant period of oscillation rather than significantly enhancing peak acceleration during seismic events. Earthquake records specific to the region were crucial for accurate assessments. The study comprehensively assessed liquefaction potential using various estimation methods, including the probability of liquefaction (PL ), liquefaction potential index (LPI), and liquefaction risk index (IR ). Moreover, this study examined liquefaction potential based on Standard Penetration Test (SPT) results, identifying susceptibility in the clayey sand layer at a depth of 3 to 12 meters. Recommendations for soil improvement measures are made to mitigate the risk. This research highlights the need for “customized seismic protocols” and emphasizes the importance of “site-specific assessments” in construction projects. By addressing susceptibility to liquefaction and proposing targeted ground improvement strategies, we contribute to safer and more resilient infrastructure development.

Liquefaction characteristics of aging earth dam body by dynamic centrifugal model test

Earth dams have been damaged or even collapsed owing to earthquake liquefaction. Although a liquefied foundation is a major factor affecting the safety of earth dams, the damage caused by the liquefaction of the dam body itself cannot be ignored, particularly for aged earth dams. However, in the presence of high water levels, liquefaction of the dam body cannot be considered solely in terms of the seismic load. Consequently, in this study we used dynamic centrifuge tests and numerical analysis to simulate the liquefaction process of an earth dam body under high water levels and analyzed the damage mechanism. The aging dam body, which can be easily liquefied, was simulated by controlling the density of the dam body, the low-density dam body exhibiting greater acceleration-amplification characteristics and displacement. Liquefaction was evident in the contact area between the slope and water level, with segmental settlement occurring. Through numerical analysis, it was evident that the core area accumulated considerable plastic deformation, and the sliding damage extended from the water contact surface to the dam toe. This study could compensate for the dearth of liquefaction model experiments of earth dams, providing a necessary reference for the seismic reinforcement of earth dams.

An experimental investigation on undrained cyclic behaviour of a saturated intact loess

There are growing evidence indicating that earthquakes occur more frequently in the Chinese Loess Plateau, which can possibly cause saturated intact loess liquefaction, leading to geological disasters. However, the cyclic behaviour of saturated intact loess is still much less investigated. In the presented work, typical intact loess was collected to carry out a comprehensive experimental investigation, including both undrained monotonic and cyclic triaxial shear tests with different confining stresses and cyclic stress. The results indicate that the intact loess shows an overall clay-like cyclic behaviour. It shows a strain softening behaviour under undrained monotonic shearing, while under undrained cyclic shearing, a well-defined failure pattern of plastic strain accumulation is observed, and an axial strain of 3 % is determined as the failure criterion. Although different excessive pore water pressure generation patterns and failure criteria are found under monotonic and cyclic conditions, a quantitative relationship is established between the monotonic and cyclic stress-strain behaviour based on the unique relationship found between axial strain and the defined allowable stress. Additional micro-structure observations and analyses further reveal the differences in loess structure destruction caused by different loading conditions. This study helps to further understand the cyclic behaviour and failure mechanism of intact loess, and to provide a useful reference for the evaluation and prevention of possible soil liquefaction failure in loess areas.

STATE-OF-THE-ART APPLICATION OF THE LOG-PILING METHOD IN THE ROLE OF SHALLOW GROUND IMPROVEMENT FOR LIQUEFACTION MITIGATION

<p>This research paper focuses on evaluating the log piling technique as a sustainable, cost-effective, and environmentally friendly solution for reducing soil liquefaction risks during earthquakes. Although this method has been used extensively in Japan, mainly aiming for complete soil layer penetration, its economic viability is questionable in cases requiring very deep soil improvements. The study highlights that shallow ground improvement can notably enhance the seismic behavior of the soil-improvement-structure system, as evidenced by the reduced total and penetration settlements caused by liquefaction. The paper presents a methodology for determining the optimal dimensions of the modified ground zone using both small and medium-scale 1-g shaking table tests. </p> <p>The small-scale tests involve a detailed parametric study, examining variables like improvement width, pile spacing, and the depth-to-thickness ratio of the improved layer. Medium-scale tests, on the other hand, are geared towards identifying the minimum effective pile length. This approach provides a practical guideline for engineers to implement log piling for small residential buildings. Additionally, the paper utilizes finite element method (FEM) effective stress analysis, incorporating a PLAXIS 2D-based constitutive model (PM4Sand) calibrated with laboratory undrained cyclic torsional tests. This model accounts for the changes in effective stress during seismic activities. Finally, the study correlates its numerical findings with the results from the 1-g shaking table experiments, offering a well-rounded perspective on the effectiveness of log piling in mitigating liquefaction risks during seismic events</p> <p> </p>