Soil Liquefaction Research Articles

Assessment of liquefaction potential of sand distributed in the coastal area of Ninh Thuan based on SPT values

The liquefaction potential of sandy soil has been widely investigated in the world for many years, especially after the Niigata and Alaska earthquakes in 1964. In which, the SPT values were mostly used for the evaluation of liquefaction potential. In Vietnam, the potential for soil liquefaction has been recently investigated. In the coastal area of Ninh Thuan province, the sand is widely distributed and often exposed on the surface. Additionally, many wind power farms have been built in this area. Thus, it is necessary to evaluate the liquefaction potential of sand distributed in this area. In this study, the potential for sand liquefaction in the coastal area of Ninh Thuan will be evaluated based on SPT values. Two common methods for evaluation of liquefaction potential proposed by Seed and Idriss; Idriss and Boulanger were employed. The research results show that at peak ground acceleration (amax) = 0.07 g and M = 5.5, the sand in the study area is non-liquefiable (safety factor against liquefaction, FS ( 1.48). However, at amax = 0.18 g and M = 7.5, the FS varies from 0.78 to 3.66 for the Seed and Idriss method and from 0.68 to 2.05 for the Idriss and Boulanger method. In general, the FS obtained from the Seed and Idriss method is higher than that obtained from Idriss and Boulanger method. Nevertheless, this insignificantly affects the overall assessment of liquefaction potential. At amax = 0.18 g and M = 7.5, the sand distributed in the study area can be liquefied at a depth of 17 m. However, it is not liquefied when the Nspt is higher than 28 ((N1) 60cs > 20).

Enhancing soil liquefaction risk assessment with metaheuristics and hybrid learning techniques

ABSTRACT Soil liquefaction has garnered significant research attention over several decades due to its profound impact on infrastructure systems in earthquake-prone regions. Given the limitations inherent in the assumptions and approximations of conventional methods, machine learning has emerged as a robust and efficient approach for predicting soil liquefaction potential. This study aims to develop a synergistic JS-CNN-XGB model, unifying the Jellyfish Search (JS) optimizer with a hybrid deep/machine learning model. This amalgamation leverages the feature extraction capabilities of the Convolutional Neural Network (CNN) alongside the classification prowess of the eXtreme Gradient Boosting (XGB) algorithm. The proposed model seamlessly integrates into a user-friendly prediction system, streamlining the liquefaction prediction process. Validation is achieved through case studies involving historical earthquake recordings with diverse classification ratios and varying input attribute quantities. Compared to existing studies, our proposed system showcases a notable 6.2% enhancement in overall liquefaction assessment accuracy, demonstrating improved detection capabilities in imbalanced and balanced datasets. In conclusion, this study underscores an automated system that presents a robust solution to the challenges posed by liquefaction potential assessment in geotechnical engineering.

Mechanical and microstructural properties of biogenic CaCO3 deposition (MICP) on a specific volcanic sediment (unwelded Tuffs) by Bacillus pasteurii and Bacillus subtilis

Microbially induced calcite precipitation has garnered significant attention in recent years as a promising and environmentally friendly process for addressing sand stabilization and soil consolidation. While its potential to stabilize sand dunes and mitigate soil liquefaction is well-documented, the applicability of MICP in the consolidation of stone materials has not been thoroughly investigated. Tuffs, which are silicate-laden pyroclasts, have historical significance as hybrid materials for cement, emphasizing their importance in cultural heritage. In previous MICP applications, there has been a lack of exploration regarding the incorporation of urease-producing bacteria (UPB) into Tuffs. Consequently, the potential of MICP in substrates such as Tuffs has been largely overlooked. The primary objective of this study is to assess the feasibility of incorporating UPB into Tuffs as a consolidating agent to facilitate calcium carbonate precipitation. We aim to investigate the microstructure of the resulting polymorphs and the previously unknown mechanism of increased resistance to W-D cycles in the treated samples at the nanoscale. In this study, we compared the cementation response of Tuff when subjected to two different UPBs by evaluating changes in key parameters, including capillary water absorption (CWA), cyclic tests such as wet-dry and salt attack, and uniaxial compressive strength. Furthermore, the characteristics of crust formation were examined using FESEM, and an in-depth analysis of the microstructure of the deposited bacterial CaCO3 was conducted. The mechanism of increased W-D resistance in Tuffs reinforced by MICP has not been previously addressed by researchers. Our study demonstrated that the increase in resistance to W-D cycles was more pronounced in samples treated with Bacillus pasteurii. Further FESEM analysis showed the presence of Bacillus pasteurii spores in the nanopores of the (W-D) exposed samples. N2 adsorption analysis revealed that nanopore alteration occurred only in samples treated with Bacillus pasteurii. Additionally, Tuffs are prone to disjoining pressure, which occurs in nanopores. Based on these observations, we postulate that the increased resistance to W-D cycles in the samples treated with Bacillus pasteurii was caused by a decrease in disjoining pressure due to the recrystallization of amorphous calcium carbonate (ACC) in the nanopores of the studied Tuff.

Evaluation of soil liquefaction in the city of Hatay triggered after the February 6, 2023 Kahramanmaraş-Türkiye earthquake sequence

This study investigates the consequences of consequences of liquefaction hazards following the February 6, 2023, Kahramanmaraş Earthquakes in Hatay, Türkiye. Field reconnaissance surveys were conducted in areas prone to liquefaction, including recent alluvial basins, the Amik (Amuq) Plain, and the Asi (Orontes) River. Specifically, attention was given to İskenderun (Alexandretta), Dörtyol coasts, the Hatay Airport region, and Demirköprü village near the Asi River. Observations indicated that geological and geomorphological factors primarily influenced liquefaction ejecta and liquefaction-induced lateral spreading in these areas. In Dörtyol, liquefaction manifestations were observed on the coastline, which has undergone natural processes, while in İskenderun, they occurred on human-made extended reclaimed land. Additionally, liquefaction manifestations in the Hatay Airport region were impacted by the drained Amik Lake, and those in Demirköprü Village were influenced by the fluvial nature of the Asi River and its sub facies. The sites experiencing liquefaction and lateral spreading mainly comprised coastal deposits, lacustrine sediments, and sub facies of the meandering river, such as point bars, abandoned channels, and levees. Consequently, the study underscores the significant correlation between geomorphology and liquefaction hazards in the context of the 2023 Kahramanmaraş-Türkiye Earthquakes. Considering these factors may facilitate further research and the identification of sites susceptible to liquefaction.

Estimation of the liquefaction potential index using analytical hierarchy process (AHP) method

In this study, we focused on estimating the liquefaction potential index using a multi-criteria method known as the Analytical Hierarchy Process (AHP). This index allows us to classify our site based on the significance of the soil liquefaction phenomenon. To achieve this, we first identified the parameters influencing liquefaction. We then assigned weights to these parameters using the AHP method, which required the development of an initial program in EXCEL. Utilizing the determined weights, a second program was developed in DELPHI to calculate the liquefaction potential index. This index enables the classification of the studied soils according to a proposed scale. The DELPHI program, equipped with a user-friendly interface, allows engineers to generate a report providing the liquefaction potential index of the studied site and its classification. The method was validated through several case studies, and the obtained results were compared in two ways: first, with the conclusions provided by a geotechnical laboratory, and second, with the results obtained using the SLAKE software, which specializes in liquefaction estimation. These comparisons showed a very good correlation with our results.

AI-Driven Prediction and Mapping of Soil Liquefaction Risks for Enhancing Earthquake Resilience in Smart Cities

AI-Driven Prediction and Mapping of Soil Liquefaction Risks for Enhancing Earthquake Resilience in Smart Cities

Simulating liquefaction-induced resuspension flux in a sediment transport model

Wave-induced liquefaction is a geological hazard under the action of cyclic wave load on seabed. Liquefaction influences the suspended sediment concentration (SSC), which is essential for sediment dynamics and marine water quality. Till now, the identification of liquefaction state and the effect of liquefaction on SSC have not been sufficiently accounted for in the sediment model. In this study, we introduced a method for simulating the liquefaction-induced resuspension flux into an ocean model. We then simulated a storm north of the Yellow River Delta, China, and validated the results using observational data, including significant wave heights, water levels, excess pore water pressures, and SSCs. The liquefaction areas were mainly distributed in coastal zones with water depths less than 12 m, and the simulated maximum potential soil liquefaction depth was 1.39 m. The liquefaction-induced SSC was separated from the total SSC of both liquefaction- and shear-induced SSCs by the model, yielding a maximum liquefaction-induced SSC of 1.07 kg·m−3. The simulated maximum proportion of liquefaction-induced SSC was 26.2% in regions with water depths of 6–12 m, with a maximum significant wave height of 3.4 m along the 12 m depth contour. The erosion zone at water depths of 8–12 m was reproduced by the model. Within 52.5 h of the storm, the maximum erosion thickness along the 10 m depth contour was enhanced by 33.9%. The model is applicable in the prediction of liquefaction, and provides a new method to simulate the SSC and seabed erosion influenced by liquefaction. Model results show that liquefaction has significant effects on SSC and seabed erosion in the coastal area with depth of 6–12 m. The validity of this method is confined to certain conditions, including a fully saturated seabed exhibiting homogeneity and isotropic properties, small liquefaction depth, residual liquefaction dominating the development of pore pressures, no influence by structures, and the sediment composed of silt and mud that experiences frequent wave-induced liquefaction.

Study on seismic response of liquefiable soil-pile group considering pile cap and soil contact

In this paper, based on the centrifuge test of liquefied soil-pile foundation system, a numerical model of liquefied soil-pile foundation-structure system is modelled by using OpenSees platform. In the simulation model, the friction effect between liquefied ground and low pile cap is considered, and the method of establishing virtual nodes is used to deal with the non-linear contact between liquefiable soil and low pile cap. The rationality and effectiveness of the numerical simulation method adopted in this paper has been verified and evaluated by comparing with the results of centrifuge experiments. A typical liquefaction soil-pile integrated finite element model is modelled using validated numerical simulation methods. The law of seismic response of the pile foundation system with different embedding depths of pile cap, different contact modes between the pile cap and saturated sand, and the thickness of the overlying saturated loose sand layer are discussed. The results show that the pile cap and pile foundation in the high pile cap system show higher seismic response characteristics than the other three low pile cap system conditions; Under the condition of different contact modes between the pile cap and the surrounding saturated sand, the peak bending moment and residual displacement of the pile foundation calculated by the bond contact are larger than calculated by the friction contact, and the deformation of pile is more significant. By comparing the working conditions of different thicknesses of overlying saturated loose sand layer, it is found that the degree of liquefaction in shallow soils is less affected by thickness of the saturated loose sand. As the thickness of saturated loose sand layer increases, the peak bending moment and residual displacement at the top of the pile also gradually increase. The change of peak bending moment at the soil interface is more obvious.

Optimal intensity measure for seismic performance assessment of shield tunnels in liquefiable and non-liquefiable soils

Relating the ground motion intensity measure (IM) and the structural engineering demand parameter is a crucial step in the performance-based earthquake engineering framework. This study investigates the selection of IM for development of probabilistic seismic demand model of urban shield tunnels subjected to earthquake ground motions in liquefiable and non-liquefiable soils. Nonlinear dynamic effective stress analyses are conducted to develop a database of the intensity measures and structural seismic responses exposed to ground shaking and soil liquefaction. Two advanced soil constitutive models (i.e., Pressure DependMultiYield03 and PressureIndependMultiYield for liquefiable and non-liquefiable soils, respectively) are employed to capture the nonlinear behavior. A suite of 23ground motion intensity measures is selected and assessed based on the evaluation criteria of correlation, efficiency, practicality and proficiency. Eventually, the multi-level fuzzy comprehensive evaluation method is employed to comprehensively consider the four evaluation criteria and establish the optimal ground motion IM suitable for probabilistic seismic demand analysis of shield tunnel structures. The obtained results show that the sustained maximum acceleration is the optimal IM for evaluating the structural seismic response, followed by the peak ground acceleration in both liquefiable and non-liquefiable soils. Peak pseudo velocity spectrum, displacement square integral and Housner spectral intensity are found to be not suitable for the probabilistic seismic demand analysis of shield tunnel structures.

Effects of Soil Liquefaction to Foundation Bearing Capacity Based on Empirical and Numerical Simulation

Abstract Soil liquefaction is one of the collateral hazards of earthquakes which can cause a soil layer to lose its bearing capacity, which can affect the stability of structures. Failure of a building structure can cost many lives, especially in strategic buildings. This research discusses bored pile foundations from the planned construction of elevated road in the Purwomartani area which located in moderate liquefaction vulnerability zone. The objective of this study is to estimate the influence of soil liquefaction on pile foundation capacity in elevated road construction plan in Purwomartani. This research uses empirical approach of Reese and O’Neil 1989 to calculate the axial bearing capacity of the pile under static and liquefaction conditions, and numerical simulation with the help of RSPile software to model the soil-pile interaction and the pile displacement under lateral loading. The data used in this research includes liquefaction potential data, foundation profile, soil investigation, standard penetration test, and laboratory tests. The analysis results showed that liquefaction caused a reduction in the foundation bearing capacity where axial bearing capacity reduce about 39,92 – 21,28% and lateral bearing capacity reduce by 5,31%.

Shear wave velocity-based evaluation of cyclic mobility type of liquefaction and validation by centrifuge model tests in LEAP

Existing study shows that small-strain shear modulus is a promising parameter for characterizing soil liquefaction resistance, while liquefaction resistance is liquefaction type dependent. In this study, firstly a revisit of laboratory tests on saturated sands was conducted to explore the relationship between liquefaction resistance CRR and small-strain shear modulus Gmax with emphasis on cyclic mobility type of liquefaction. The investigation indicates that in the stress-normalized space of cyclic resistance and small-strain shear modulus, the fitting curve of soil testing data does not always approach to the coordinate origin and there will be an intercept on the abscissa axis. Based on this finding, a more general form of the power function between liquefaction resistance and small-strain shear modulus is proposed. Then, undrained cyclic triaxial tests were conducted in conjunction with the data available from LEAP to establish the power function between CRR and Gmax for medium dense to dense Ottawa F-65 sand, which leads to an updated characterization model on the basis of Zhou-Chen model. Finally, centrifuge model tests of submerged gently sloping ground of Ottawa F-65 sand conducted at Zhejiang University (i.e., ZJU) for LEAP were used to compile liquefaction and non-liquefaction case histories with shear wave velocity measurement to investigate the validity of the updated model for evaluating the cyclic mobility type of liquefaction. The test results show that the updated model could classify the case history datasets produced by centrifuge model tests well. And the further consideration of initial shear stress acting on the slope could enhance the evaluation performance of this characterization model, which is worth of further research.

Peculiarities of using small-diameter bored piles for effective solving of geotechnical problems

Abstract. The peculiarities of the use of small-diameter drill piles in modern construction considered, with an emphasis on their advantages and areas of application in specific conditions. Two main types of piles distinguished: cast-in-place, which characterized by continuous reinforcement and filling with concrete or cement mortar, and composite, where the load transfers to reinforcing elements. Main advantages of small-diameter bored piles noted, including the possibility of performing work in confined spaces, reducing the level of noise and vibrations, a variety of drilling technologies, the possibility of application in geological conditions of varying complexity, etc. Particular attention paid to the areas of application of small-diameter bored piles, including the installation of new foundations, underpinning of existing structures, soil improvement and land-slide protection. The main groups of factors that can influence the choice of small-diameter bored piles as the main design decision for various fields of application considered, including: - physical factors (restricted access, remoteness of the area, distance of piles to existing structures); - subsoil factors (difficult geological conditions, soil liquefaction tendency); - environmental factors (sensitivity to vibration/noise, hazardous or contaminated soils); - necessity of adaptation to existing structures; - load/settlement requirements; - economic factors. Limitations for the use of small-diameter drill piles from the point of view of their efficiency described. An example of the effective practical use of small-diameter bored piles in the confined conditions of dense urban development in close proximity of metro tunnels with increased requirements regarding the level of vibrations and noise considered. The task of minimizing subsidence of the designed residential and office complex and the impact on surrounding buildings and structures solved. The compliance of the adopted design decisions confirmed by means of field tests, as well as using the results of settlements monitoring. Attention focused on the need for further improvement of design approaches and technological solutions to optimize the efficiency of small-diameter bored piles for solving geotechnical problems.

Vibro stone as periodic wave barriers for train-induced vibration attenuation of Lamb and surface waves

The rising cost of traditional foundations (e.g., concrete piles) and their environmental limits have prompted using natural ways to strengthen poor soils. The Vibro stone column technique has grown in popularity in the building industry because it is a cost-effective and ecologically friendly way of strengthening the soil-bearing capacity of poor soil and avoiding the risk of soil liquefaction. The usage of stone columns in soft clay as periodic wave barriers to attenuate undesirable waves is numerically examined in this paper. The finite element method was used to investigate the band gap characteristics of Lamb and surface waves in the periodic structures of the stone column. In both wave analyses, eigenfrequency simulation, mode shapes simulation, frequency domain simulation, and time transient simulation are used to investigate the traditional vibroflot shape and proposed square and notch types vibroflot. It was established that the notch type vibroflot performed excellently in attenuating Lamb and surface waves compared to the traditional and square vibroflot types. The numerical outcomes in the frequency and time domains support the attenuation impact of finite Vibro stone in the band gap as well as the phenomena of attenuation broadening brought on by the dissipation of leak modes into the bulk. As a result, the proposed barriers can be used to shield the broadband incident waves generated by both Lamb and surface waves by trains in a tunnel.

Shaking table tests and numerical analysis of monopile-supported offshore wind turbines under combined wind, wave and seismic loads

Currently, large-diameter monopile-supported offshore wind turbines (OWTs) are widely used in offshore areas of China. However, considerable numbers of wind farms are located in seismically active areas with liquefiable soil layers. Therefore, shaking table tests and numerical simulation based on a scaled model of Siemens SWT-4.0-130 OWTs were carried out to investigate the failure mechanism of the OWT system in liquefiable sand under combined wind, wave and seismic loads. The scaling law focusing on the governing physical mechanism of the OWT system considering multi-field coupling are presented and verified. The dynamic responses of the OWT and the excess pore pressure fluctuation around the soil-monopile domain in different operating states are discussed and compared. The results show that the proposed scaling laws can well restore the dynamic characteristics of the prototype. The seismic excitation is the dominant load for inducing the structural response under combined wind, wave and seismic loads. Due to the coupling effect, the dynamic responses under combined wind and wave loads were slightly less than the superposition of structural responses under separated wind or wave loads. Liquefaction of the shallow soil layer within the range of four times the pile diameter was detected when the PGA reached 0.4 g (three-dimensional input) or 0.64 g (one-dimensional input), which induced obvious tilt and settlement of the OWT model after the test. The sudden increase in the pore pressure resulted in the liquefaction of soil, which further led to a significant decrease in the natural frequencies and decay of the acceleration responses at the tower top. The above findings are expected to provide valuable experience for the 1 g underwater shaking table tests on OWT systems and insights for the practical design of OWTs in seismically active areas.

1 g shaking table test for seismic response for a monopile foundation of offshore wind turbine

A large number of offshore wind farms have been recently developed in offshore wind turbines (OWTs) in seismically active regions. Currently, there is no dedicated seismic design code tailored to offshore wind turbines, resulting in their seismic design often mirroring that of buildings. However, the intricate soil-water-structure interaction (SWSI) and its influence on the system's seismic response is a crucial consideration for OWTs. This study initially investigated the impact of SWSI on the natural frequency of OWTs using shaking table tests, with findings showing that considering SWSI results in a significant reduction in the natural frequency of OWTs. Subsequent physical modeling on a shaking table examined the effects of monopile diameter (D) and driven length (Ld), as well as the presence of a shallow wheel with different diameters (Dw) within a hybrid monopile. The analysis focused on tower acceleration, tower lateral displacement, and soil liquefaction during seismic loading. Based on the test results, increasing the monopile diameter and utilizing the hybrid monopile increases the turbine's seismic response. However, increasing the monopile driven length emerged as a suitable solution to improve the seismic response in offshore wind turbines.

Quantifying near-fault motion effects on soil liquefaction through effective stress site response analysis

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.

Cascading hazards of a major Bengal basin earthquake and abrupt avulsion of the Ganges River

Earthquakes present severe hazards for people and economies and can be primary drivers of landscape change yet their impact to river-channel networks remains poorly known. Here we show evidence for an abrupt earthquake-triggered avulsion of the Ganges River at ~2.5 ka leading to relocation of the mainstem channel belt in the Bengal delta. This is recorded in freshly discovered sedimentary archives of an immense relict channel and a paleo-earthquake of sufficient magnitude to cause major liquefaction and generate large, decimeter-scale sand dikes >180 km from the nearest seismogenic source region. Precise luminescence ages of channel sand, channel fill, and breached and partially liquefied floodplain deposits support coeval timing of the avulsion and earthquake. Evidence for reorganization of the river-channel network in the world’s largest delta broadens the risk posed by seismic events in the region and their recognition as geomorphic agents in this and other tectonically active lowlands. The recurrence of comparable earthquake-triggered ground liquefaction and a channel avulsion would be catastrophic for any of the heavily populated, large river basins and deltas along the Himalayan arc (e.g., Indus, Ganges, Brahmaputra, Ayeyarwady). The compounding effects of climate change and human impacts heighten and extend the vulnerability of many lowlands worldwide to such cascading hazards.

A quantitative study of the effects of physical properties and external loads on the liquefaction of saturated sand based on an intelligent numerical cyclic triaxial test system

ABSTRACT Soil liquefaction would cause significant damage to the safety of cargo transportation. The aim of this article is to conduct a quantitative study of the influence of the main physical characteristic parameters of saturated sand and external loads on its liquefaction. On the basis of the physical cyclic triaxial test (CTT), the finite element simulation model and PSO-BP neural network prediction model and importance analysis model were optimised in this study. Based on this, an innovative intelligent numerical CTT system for saturated sand was constructed. The research results indicate the influence of external load, effective internal friction Angle and plasticity index on the liquefaction of saturated sand is significant, and the average weight is 40.15%, 29.15% and 25.05%, respectively. In this paper, the relevant research provides a theoretical basis for effective control of sand liquefaction and provides new ideas and feasible solutions for subsequent research on sand liquefaction.

Effects of Vertical Motion on Uplift of Underground Structure Induced by Soil Liquefaction

The uplift of underground structures induced by soil liquefaction can damage underground structure systems. Numerical simulations have shown that uplift is positively correlated with the energy of horizontal input motion. However, the effects of vertical input motion on uplift have not been studied comprehensively in the past. Previous studies on the vertical motion concluded that the effects of vertical motion on uplift depend on the overall characteristics of earthquake motion. These motion characteristics have only been studied separately in previous studies. A comprehensive study to explore the interactions and overall effects of these characteristics on the uplift of underground structures is essential. In this study, the FLAC program with the PM4Sand model was used as a numerical tool to explore the effects of vertical input motion on the uplift of underground structures. The numerical model was calibrated using centrifuge test results, and 48 earthquake motions were selected as input motions to study the effects of the overall characteristics of earthquake motions on the uplift of underground structures. The simulation results show that the frequency content characteristics of horizontal and vertical motion are the major factors affecting the uplift magnitude and the responses of liquefiable soils. However, most simulation cases show that the inclusion of vertical motion causes a 10% difference in the tunnel uplift, compared to cases without vertical motion.

Excess pore water pressure response of soil inside the mini bucket embedded in saturated soil under seismic loading

This study investigates the behavior of suction bucket foundations during seismic loading induced soil liquefaction through shaking table experiments using both steel and 3D printed mini buckets. The pore water pressure response of the soil inside and around the mini buckets was monitored, and the results show that excess pore water pressure ratios greater than 1.0, indicating liquefaction occurred inside and around the buckets. In order to verify whether the soil plug liquefies under seismic loading, a floating ball experiments was specifically designed. The findings suggest that behavior of suction bucket foundations may differ from that of gravity-based foundations when experiencing soil liquefaction, owing to their unique semi-enclosed geometric structure and suction installation method. The appropriately weighted steel mini bucket has the advantage of being less prone settlement in the liquefied soil, making it suitable as a monitoring platform for soil liquefaction.