Static Undrained and Drained Behaviour of Gangetic Sand
摘要
The seismic events in Alaska and Niigata in 1964 sparked considerable interest in earthquake engineering, highlighting liquefaction as a primary cause of structural damages. Following these events, liquefaction studies became a focal point for geotechnical engineers, with different methods for assessing its potential. Previous studies on this domain have emphasized the significance of loading and drainage conditions in determining soil behavior. While most research has focused on dynamic loading effects, static liquefaction investigations have received limited attention. Undrained conditions typically trigger liquefaction, yet the drained behavior is also crucial for long-term stability analysis. The current research is an experimental investigation for analyzing the behaviour for gangetic sand collected from Indo-Gangetic Plains in the banks of Solani River near IIT Roorkee. The samples are subjected to static triaxial tests with various confining pressures and relative densities under undrained and drained conditions to analyze the realistic behaviour of soil within a unique framework. The influence of shearing in terms of its stress–strain variations, effective stress (p-q) path and pore pressure ratio is analyzed for identifying the liquefaction susceptibility. In addition, effect on the Skempton’s pore pressure parameter (A) and angle of obliquity (β) is also investigated in the context of liquefaction. For the drained condition, stress–strain as well as the volumetric change variations has been studied. It is noted that the initial state, confining pressures, drainage conditions and the stress history of soil has a greater influence in the shear strength of Gangetic sand.