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.

Solidified soil (SS) is widely applied for resource utilization of excavated soil (ES), however the waste solidified soil (WSS) may pose environmental hazards in future because of its high pH (>10). WSS is unsuitable for landfill but can be raw materials for preparing recycled solidified soil (RSS) with better mechanical properties than SS. This investigation used OPC and alkali-activated slag (AAS) as binders to solidify ES and WSS and prepare RSS. The mechanical properties of RSS were experimentally verified to be better than SS, increased by over 76 %. The mechanism is that the clay particles in WSS have been solidified to form sand-like particles or adhere to natural sand, resulting in increasing content of sand-sized particles, and the residual clay particles undergo cation exchange under the high pH and Ca2 + content, resulting in a decrease in zeta potential, reducing diffusion layer thickness. As a result, the flowability of RSS increases under the same liquid to solid ratio. The residual unreacted binder particles and high pH in WSS are beneficial for the early and final compressive strength increase of RSS, which allows preparing RSS with lower cost and carbon emission. Finally, the utilization of WSS has significant environmental benefits.

Evaluating the stability of coral islands and reefs in dynamic marine environments, such as waves, tsunamis, storm surges, and earthquakes, is a critical scientific issue in the field of marine geotechnical engineering. Nansha coral sand was used as the study object, and stress-controlled drained and undrained cyclic-loading tests were conducted. The undrained excess pore-water pressure and the drained cumulative volumetric strain of saturated coral sand were determined at various non-plastic fine contents (FC), relative density (D-r), and cyclic stress ratio (CSR). The results indicated that cumulative volumetric strain (epsilon(vp)) developed in coral sand via two modes: cyclic stabilisation and cyclic creep. Analyses revealed that when the potential damage coefficient (DP) x CSR 0.05, epsilon(vp) transitioned into the cyclic creep mode. Utilising cumulative dissipation energy as a linking factor showed an arctangent function relationship between the excess pore water pressure ratio (R-u) and epsilon(vp) values of saturated coral sand with different FC, D-r, and CSR. This relationship was applicable to both stress- and strain-controlled cyclic-loading tests. Parameters m and n of the R-u-epsilon(vp) function model increased with an increasing CSR. Additionally, an increase in the D-r or FC resulted in a decrease in m and an increase in n. Multiple regression analysis further revealed that model parameters corrected for compactness and cyclic stress levels exhibited distinct trends as the void ratio (e) increased. Specifically, CSR alpha x m(D)(R) decreased, and CSR1-alpha x n(D)(R) increased. Both parameters displayed a single power function relationship with e. Based on these findings, a coupled incremental model for the cyclic pore pressure and volumetric strain of saturated coral sand, based on energy conversion, was developed.

This study investigates the physicochemical properties of Soil-Like Material (SLM) recovered from aged Municipal Solid Waste (MSW) dumps in Anantapur, Andhra Pradesh, India, and assesses its potential for reuse. The SLM, which constitutes 68%-75% of the excavated waste, was analyzed for key parameters including total dissolved solids (TDS), chemical oxygen demand (COD), electrical conductivity (EC), and heavy metal concentrations. Results revealed that the organic content of SLM ranged from 6% to 20%, significantly higher than that of local soils (1.5%). The leachate produced from SLM showed elevated levels of TDS (500-1,200 mg l-1), COD (150-270 mg l-1), and heavy metals such as copper (Cu), lead (Pb), chromium (Cr), and zinc (Zn). Cu and Pb concentrations were found to be 27 and 26 times higher than those in local soil extracts, posing substantial risks to groundwater and soil quality. Other metals, including nickel (Ni), arsenic (As), and cadmium (Cd), also exceeded permissible limits. These findings suggest that while SLM has potential for reuse, its high contamination levels require treatment methods such as soil washing, heating, or stabilization with additives like lime or fly ash to reduce environmental risks. Without proper treatment, the direct use of SLM could result in substantial ecological damage. The study highlights the importance of sustainable landfill site rehabilitation and the development of safe strategies for the reuse of SLM to mitigate potential environmental impacts.

Structures constructed on collapsible soil are prone to failure under flooding. Agro-waste like rice husk ash (RHA) and its geopolymer (LGR), consisting of lime (L), RHA, water glass (Na2SiO3), and caustic soda (NaOH), present a potential solution to address this issue. RHA and LGR were mixed up to 16% to improve the collapsible soil. Samples were remolded at optimal water content and maximum dry density for strength and collapsible potential tests. Unconfined compressive strength, deformation modulus, and soaked California bearing ratio exhibit exponential improvement with the inclusion of LGR. Additionally, for comparison of microstructural characteristics, analyses involving energy-dispersive X-ray spectroscopy (EDAX) and scanning electron microscope (SEM) were conducted on both virgin and treated specimens. LGR resulted in the emergence of new peaks of sodium silicates and calcium silicates, as indicated by EDAX. The formation of H-C-A-S gel and H-N-A-S gel observed in SEM suggests the development of bonds among soil particles attributed to geopolymerization. SEM reveals the transformation of the inherent collapsible soil from a dispersed and silt-dominated structure to a reticulated structure devoid of micro-pores following the incorporation of LGR. A numerical model was constructed to forecast the performance of both virgin and stabilized collapsible soils under pre- and post-flooding conditions. The outcomes indicate an enhancement in the soil's bearing capacity upon stabilization with 12% LGR. The implementation of 12% LGR significantly resulted in a lower embodied energy-tostrength ratio, emissions-to-strength ratio, and relatively lower cost-to-strength ratio compared to the soil treated with 16% cement kiln dust (CKD). (c) 2025 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/

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.

This study employed geo-electrostratigraphic and hydrogeological information to model and assess subsurface structure and hydrogeological properties within a major coastal environment in Nigeria's Niger Delta region, offering a high-resolution approach to groundwater resource management. The selection of the study area was predicated on its critical residential, agricultural, and economic significance, as well as its susceptibility to hydrogeological challenges arising from rapid urbanization and industrial activities. Unlike previous studies that utilized these methods independently, this research combined different geoelectrical technologies to enhance the accuracy of subsurface characterization. The results delineated four distinct geo-layers characterized by specific resistivity values, thicknesses, and depths, providing crucial insights into groundwater infiltration, storage potential, and contamination risks. The first geo-layer (motley topsoil) had resistivity values ranging from 95.2 to 1463.7 Qm. The second layer (sandy clay) exhibited resistivity values ranging from 8.8 to 2485.1 Qm. The third layer, identified as fine sand, exhibited resistivity values ranging from 72.5 to 1332.7 Qm. The fourth layer comprised coarse sands and it exhibited a mean resistivity of 525.98 Qm, indicating a well-drained permeable formation that could serve as an additional aquifer unit. A key innovation of this study was the quantitative assessment of hydrogeological parameters, including anisotropic coefficient, transverse resistance, longitudinal conductance, and groundwater yield potential index. The anisotropic coefficient ranged from 1.0 to 1.78 (mean: 1.17), revealing minimal sediment invasion and confirming the dominance of arenaceous sediments in the Benin Formation. The groundwater yield potential index varied from 3.14 x 102 to 8.1465 x 104 Qm2, highlighting areas of significant aquifer potential. The longitudinal conductance analysis revealed that 69 % of the study area has low aquifer protectivity, underscoring the region's vulnerability to contamination. Another novel contribution was the evaluation of soil corrosivity, which has direct implications for infrastructure longevity. Results indicate that 86 % of the study area is non-corrosive, making it suitable for long-term pipeline installation, a factor rarely integrated into groundwater assessments. The study alsoadvances understanding of the Benin Formation by linking resistivity variations to arenaceous-argillitic intercalations, and this significantly influences groundwater movement and contaminant transport. By synthesizing resistivity models, hydrogeological parameters, and contamination risk assessments, this research provides a more holistic framework for sustainable groundwater management. Furthermore, this research offers a robust framework for similar hydrogeophysical assessments in other regions with comparable geological and hydrological settings. (c) 2025 Guangzhou Institute of Geochemistry, CAS. Published by Elsevier BV. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

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.

Clay soils are known to have a high swelling pressure with an increase in water content. This behavior is considered a serious hazard to structures built upon them. Various mechanical and chemical treatments have historically been used to stabilize the swelling behavior of clay soils. This work investigates the potential use of shredded plastic waste to reduce the swelling pressure and compressibility of clay soils. Two types of highly plastic clay (CH) soils were selected. Three different dimensions of plastic waste pieces were used, namely lengths of 0.5 cm, 1.0 cm, and 1.5 cm, with a width of 1 mm. A blend of plastic-cement waste with a ratio of 1:5 by weight was prepared. Different fractions of the plastic-cement waste blend with a 2 wt.% increment were added to the clay soil, which was then remolded in a consolidometer ring at 95% relative compaction and 3.0% below the optimum. The zero swell test, as per ASTM D4546, was conducted on the remolded soil samples after three curing periods: 1, 2, and 7 days. This method ensures the accurate evaluation of swell potential and stabilization efficiency over time. The experimental results showed that the addition of 6.0-8.0% of the blend significantly reduced the swelling pressure, demonstrating the mixture's effectiveness in soil stabilization. It also reduced the swell potential of the expansive clay soil and had a substantial effect on the reduction in its compressibility, especially with a higher aspect ratio. The compression index decreased, while the maximum past pressure increased with a higher plastic-cement ratio. The 7-day curing time is the optimum time to stabilize expansive clay soils with the plastic-cement waste mixture. This study provides strong evidence that plastic waste can enhance soil mechanical properties, making it a viable geotechnical solution.

This paper presents a comprehensive assessment of the accuracy of high-frequency (HF) earth meters in measuring the tower-footing ground resistance of transmission line structures, combining simulation and experimental results. The findings demonstrate that HF earth meters reliably estimate the harmonic grounding impedance (R25kHz) at their operating frequency, typically 25 kHz, for a wide range of soil resistivities and typical span lengths. For the analyzed tower geometries, the simulations indicate that accurate measurements are obtained for adjacent span lengths of approximately 300 m and 400 m, corresponding to configurations with one and two shield wires, respectively. Acceptable errors below 10% are observed for span lengths exceeding 200 m and 300 m under the same conditions. While the measured R25kHz does not directly represent the resistance at the industrial frequency, it provides a meaningful measure of the grounding system's impedance, enabling condition monitoring and the evaluation of seasonal or event-related impacts, such as damage after outages. Furthermore, the industrial frequency resistance can be estimated through an inversion process using an electromagnetic model and knowing the geometry of the grounding electrodes. Overall, the results suggest that HF earth meters, when correctly applied with the fall-of-potential method, offer a reliable means to assess the grounding response of high-voltage transmission line structures in most practical scenarios.