Liquefaction hazard analysis is crucial in earthquake-prone regions as it magnifies structural damage. In this study, standard penetration test (SPT) and shear wave velocity (Vs) data of Chittagong City have been used to assess the liquefaction resistance of soils using artificial neural network (ANN). For a scenario of 7.5 magnitude (Mw) earthquake in Chittagong City, estimating the liquefaction-resistance involves utilizing peak horizontal ground acceleration (PGA) values of 0.15 and 0.28 g. Then, liquefaction potential index (LPI) is determined to assess the severity of liquefaction. In most boreholes, the LPI values are generally higher, with slightly elevated values in SPT data compared to Vs data. The current study suggests that the Valley Alluvium, Beach and Dune Sand may experience extreme liquefaction with LPI values ranges from 9.55 to 55.03 and 0 to 37.17 for SPT and Vs respectively, under a PGA of 0.15 g. Furthermore, LPI values ranges from 25.55 to 71.45 and 9.55 to 54.39 for SPT and Vs correspondingly. The liquefaction hazard map can be utilized to protect public safety, infrastructure, and to create a more resilient Chittagong City.

Paleoliquefaction investigations are crucial for assessing seismic hazard potential and identifying regions susceptible to liquefaction, which is essential for seismic risk-sensitive land-use planning. This research aimed to identify paleoliquefaction sites by reviewing documented descriptions of the damages and ground deformations in Bangladesh during three significant historical earthquakes: the Bengal Earthquake (1885), the Great Assam Earthquake (1897), and the Srimangal Earthquake (1918). A paleoliquefaction map for Bangladesh was generated, locating the paleoliquefaction sites during these three major historical earthquakes. In addition, Standard Penetration Test (SPT) blow count and Down-hole Seismic Tests (DST) were conducted at selected locations to assess the Liquefaction Potential Index (LPI) by using deterministic (simplified) and probabilistic procedures. The results confirmed a high likelihood of liquefaction during future large-magnitude earthquakes. The research outcome will help to distinguish and characterize Bangladesh's susceptible regions to soil liquefaction during potential earthquakes in the future and is recommended for consideration in large-scale construction or development plans.

The study area, located in Martil, northern Morocco, lies in a region with high seismic risk, near a subduction zone. As a result, loose soils, such as sands, lose their shear strength under seismic loads due to an increase in pore water pressure, leading to deformations. The objective of this study is to assess the risk of soil liquefaction at the site where the Lalla Khadija High School will be constructed. The method used to evaluate the liquefaction risk is based on in-situ test results, as proposed by Seed and Idriss (J Soil Mech Found Div 97(9):1249-1273, 1971. https://doi.org/10.1061/JSFEAQ.0000981). Specifically, the liquefaction potential is assessed using data from the cone penetration test (CPT). This methodological approach combines a qualitative evaluation of susceptibility, which identifies the presence of fill materials and Plio-Quaternary sands-potentially liquefiable materials. At this stage, a quantitative evaluation of susceptibility is performed by calculating the safety factor, defined as the ratio between the normalized cyclic resistance ratio of the soil and the normalized cyclic stress ratio induced by the earthquake. The results of the CPT indicate that the normalized penetration resistance (qc1Ncs) consistently exceeds 160, which reflects sufficient soil strength. Consequently, the analysis confirms the absence of liquefaction risk in the sandy layers between depths of 1.8 m and 14 m. Therefore, the studied site has no liquefaction potential. This study has certain limitations. It relies solely on the method of Seed and Idriss (1971) to assess liquefaction risk, thereby restricting comparisons with alternative approaches. Additionally, the analysis focuses exclusively on the Lalla Khadija High School site, preventing extrapolation to the entire Martil plain. Nevertheless, by confirming the absence of liquefaction risk at this site, the study enables optimized foundation design, ensuring the stability of the infrastructure in the event of an earthquake. This contributes to occupant safety and improved seismic risk management in the region.

Comprehensive assessment of liquefaction potential is an important aspect of understanding the liquefaction susceptibility and risk of any region. In India, liquefaction potential assessment (LPA) was carried out as a part of seismic microzonation, and a lot of research work has been reported for major cities/regions. A review of LPA for major cities/regions in India was presented in this study for better understanding of the factors considered in the assessment. In addition, a comprehensive LPA considering the susceptibility, probability, and associated seismic risk on existing structures was evaluated for eight sites in Roorkee region, India. The factor of safety against liquefaction (FSL) and liquefaction potential index (LPI) are evaluated using existing standard penetration test (SPT) data. Also, liquefaction probability (PL) and post-liquefaction settlement (SL) are theoretically estimated to frame a comprehensive LPA. This study is the first of its kind to frame a comprehensive LPA considering both the susceptibility indices (FSL and PL) and liquefaction damage indices (LPI and SL). The results indicate that a high risk of liquefaction and surface manifestations are possible for the selected sites for considered seismic scenario. Fines content and the number of borehole layers are critical in influencing the resistance to liquefaction and surface manifestations. Estimation of SL from SPT N number and volumetric strain approach were found in good agreement with the interpretations obtained from the LPI values. It can be stated that for any design of structures against liquefaction, FSL must be higher than 1.20, as this can be evident from the available literature and the presented case study of Roorkee region.

The increasing frequency of earthquakes in Kuwait raises concerns regarding soil liquefaction. Currently, there is no soil liquefaction potential map for Kuwait, even for soil profiles along coastal shores, where the groundwater table is near the surface. To address this gap, investigations and assessments were carried out and ArcMap 10.8 was used to establish five soil liquefaction hazard potential maps for Kuwait for different earthquake scenarios based on available borehole logs. The popular methods for evaluating soil liquefaction hazard are the simplified approach proposed in the National Center for Earthquake Engineering Research workshop, which is based on standard penetration tests (for determining the safety factor), and Luna and Frost's (1998) method to assess the liquefaction potential index. Notably, standard penetration test blows were used to investigate the variations in the soil relative density below the surface, describe seismic sources, and estimate peak ground accelerations (calculated using Cornell's equation and verified using ground-motion models). Southern Kuwait was highly vulnerable to soil liquefaction potential (local earthquake moment magnitude of 5.5); this was confirmed by the documented structural damage. Such maps can be used to identify the areas vulnerable to soil liquefaction and limit the risk to infrastructure.

Teluk Segara and Sungai Serut in Bengkulu City are significantly developed districts. This paper presents a liquefaction vulnerability map for the housing areas. The geophysical and geotechnical data for the study area are collected. A semi-empirical analysis is performed to estimate the liquefaction potential. The liquefaction potential index is estimated. The maps describing geophysical characteristics, liquefaction, and seismic vulnerabilities are discussed. The results showed that the study area could undergo moderate to strong motion during the most significant earthquake in Bengkulu City. It can trigger liquefaction in areas near the river dominated by sandy soils. The integrated weighted factor method, called the cumulative liquefaction susceptibility (CLSI), is proposed to estimate the level of liquefaction susceptibility. The factor considered several parameters such as liquefaction potential index, peak ground acceleration, seismic vulnerability, and site classification. The result shows that the study area is characterised as moderate liquefaction susceptibility. The integrated method can be implemented to understand liquefaction quantification in engineering practice better.

Microbially induced calcium carbonate precipitation (MICP) technology is an emerging and environmentally sustainable method for improving the strength and stiffness of soil. Specifically, this innovative approach has gained favor in marine engineering due to the advantaged compatibility between precipitated calcium carbonate induced by MICP and coral sand. Sand containing fines is susceptible to liquefy. Whereas, the impact of fines contents on cyclic behavior of MICP-treated calcareous sand remains uncertain. Consequently, this technical note aims to investigate the liquefaction behavior of biocemented calcareous silty sand by conducting undrained cyclic triaxial shear tests and microscopic analysis. The results revealed the patterns of the excess pore water pressure curves and cyclic deformation characteristics as the fines contents increased. The liquefaction resistance of biocemented sand initially decreases with the addition of fines but subsequently exhibits an increasing trend. Microscopic analysis showed that at the cementation level with the cementation solution concentration of 1 mol/L, the calcium carbonate crystals are mainly attached to the surface of sand grains and this pattern does not directly affect the force chain.

In soil mechanics, liquefaction is the phenomenon that occurs when saturated, cohesionless soils temporarily lose their strength and stiffness under cyclic loading shaking or earthquake. The present work introduces an optimal performance model by comparing two baselines, thirty tree-based, thirty support vector classifier-based, and fifteen neural network-based models in assessing the liquefaction potential. One hundred and seventy cone penetration test results (liquefied and non-liquefied) have been compiled from the literature for this aim. Earthquake magnitude, vertical-effective stress, mean grain size, cone tip resistance, and peak ground acceleration parameters have been used as input parameters to predict the soil liquefaction potential for the first time. Performance metrics, accuracy, an area under the curve (AUC), precision, recall, and F1 score have measured the training and testing performances. The comparison of performance metrics reveals that the model Runge-Kutta optimized extreme gradient boosting (RUN_XGB) has assessed the liquefaction potential with an overall accuracy of 99%, AUC of 0.99, precision of 0.99, recall value of 1, and F1 score of 1. Moreover, model RUN_XGB has a true negative rate of 0.98, negative predictive value of 1, Matthews correlation coefficient of 0.98, and average classification accuracy of 0.99, close to the ideal values and presents the robustness of the RUN_XGB model. Finally, the RUN_XGB model has been recognized as an optimal performance model for predicting the liquefaction potential. It has been noted that a low multicollinearity level affects the prediction accuracy of models based on conventional soft computing techniques, i.e., logistic regression. This research will help researchers choose suitable hybrid algorithms and enhance the accuracy of seismic soil liquefaction potential models.

For the last few decades, for the liquefaction susceptibility assessment of a location, Standard Penetration Test (SPT) based methods have been generally practiced. In this research, the liquefaction potential of Dhaka Metropolitan Development Plan (DMDP) area has been analyzed using three existing Cone Penetration Test (CPT) based methods. CPT (CPTu and SCPT) data have been collected from 546 locations of the DMDP region covering 1530 square kilometer area and have been analyzed to assess the liquefaction potential. Bangladesh is located in the junction of Indian and Eurasian plate, which makes this country vulnerable to earthquakes. A magnitude 7.5 earthquakes and Peak Ground Acceleration (PGA) value of 0.21 g at the surface have been used to evaluate the liquefaction susceptibility of the region using the three CPT-based techniques and another CPT-based technique has been employed to evaluate the liquefaction susceptibility of the region using variable surface PGA based on Modhupur scenario. Liquefaction potential maps have been proposed and compared for these four methods. It has been found that more than 60% of the study area falls within the LPI range which indicates moderate to relatively high liquefaction vulnerability. The liquefaction susceptibility of the three methods has been found to be in agreement and possible reasons of deviation in any particular method have been explained. Also, Ishihara 1985 proposed LPIISH has been estimated and compared with Iwasaki's LPI values. It has been observed that the difference in results using LPI and LPIISH are not significant. The seismic microzonation and liquefaction analyses will help engineers, planners and relevant professionals to get prior idea about the seismic vulnerability of any part of the DMDP region and take measures beforehand to avoid any damaging consequences.

Liquefaction of sub-soil is a phenomenon in which partially saturated or saturated loose cohesionless sub-soil, especially loose fine sand, significantly lose their strength and stiffness in response to applied stresses. It occurs generally during earthquake shakings because of the generation of surplus pore water pressure, causing it to lose its effective stress and act like a liquid. Essentially, prediction of the liquefaction severity accurately is very important for liquefaction-prone sites for different seismic conditions. All the structures that are constructed on sub-soil are susceptible to liquefaction and can get damaged as a result of earthquake ground motion. Since earthquakes are one of the most disastrous events, analysis for sub-soil needs to be conducted to understand the soil behavior and its stability against liquefaction at different sites. There are several simplified techniques to assess liquefaction potential on the basis of standard penetration test (SPT), cone penetration test (CPT), and shear wave velocity (Vs) test. In this paper, simplified liquefaction analysis has been carried out based on SPT data for 10 sites in Bahraich District situated in Uttar Pradesh. Liquefaction potential index (LPI) has been calculated and the level of liquefaction severity is classified. It was observed that out of 10 site that have been evaluated 5 had moderate to high severity; while, the remaining 5 sites had high to very high severity. The classification helped in preliminary comprehension of the liquefaction susceptibility of the sites selected for construction.