Bangladesh is one of the world's most disaster-prone areas. The northwest region of Bangladesh is the most seismically active region. Dinajpur is the district closest to the Himalayan frontal thrust, making it the most vulnerable to earthquake-related liquefaction. Therefore, the in-situ parameters are used to assess the liquefaction susceptibility of the subsurface geology for the Dinajpur district in terms of soil liquefaction safety factor (FS), the liquefaction potential index (LPI), and the liquefaction probability (PL). This study used deterministic and probabilistic techniques to estimate the liquefaction susceptibility of the area based on standard penetration test (SPT) N values. SPT data was collected at 160 different places within the study area. In an earthquake scenario with Mw = 6.5, liquefaction resistance is evaluated at each location using a 0.20g peak ground acceleration (PGA). The results of the SPT-based liquefaction assessment techniques were found to be considerably different. The soil strata prone to liquefaction in different zones of the city have been determined based on a common comparison. According to deterministic and probabilistic techniques, it has been found that, out of 160 locations, 36 and 50 sites are susceptible to liquefaction. Then, using geospatial techniques (IDW interpolation), hazard maps were created depending on the potential for liquefaction of particular locations. Finally, using an independent secondary dataset, the resulting hazard maps were validated to examine the developed approach. The obtained R2values for each regression analysis event were more than 0.79. Therefore, the produced hazard map may be utilized successfully for planning, management, and long-term development of the studied locations. Doi: 10.28991/CEJ-2022-08-07-010 Full Text: PDF

This research investigates the characteristics of organic soil from southwest Bangladesh and the influence of sand columns on the void ratio (V0), consolidation coefficient (CC), and volume compressibility (CV) of stabilized soil. On the laboratory scale, cylindrical columns of varying diameters were extruded through organic soil samples and stabilized with 3%, 5%, 8%, 10%, and 23% sand in various geometries. After evaluating the engineering parameters, a series of 1-D consolidation experiments were performed to assess the effect of the sand column on stabilized soil samples. According to the Unified Soil Classification System (USCS), the organic soil used in this research is defined as organic silt (OH). According to the findings, the organic soil has a liquid limit of 118% and its particles pass through a 0.075 mm sieve. By incorporating sand columns, rapid consolidation was obtained, and the sample containing 77% organic soil and 23% sand exhibited the best consistent compressibility features. The effects of column number and geometry on the compressibility behavior of organic soil samples were also examined. The results for the 77% organic soil and 23% sand in a single column and the 82% organic soil and 8% sand in a double column are nearly identical. This study reveals that stabilization with sand columns may significantly enhance the physical and consolidation behavior of organic soil in southwest Bangladesh.