Undrained cyclic behavior of Palar sand under variable confining pressure

The fundamental characteristics of sands significantly affect the behaviour of different types of soil. Massive liquefaction after a severe earthquake can cause significant damage to buildings and infrastructure. Soil subjected to earthquake motion undergoes random changes in strain and frequency throughout the period of shaking. The spatial and temporal complexity of dominant motions is usually addressed through simple strain controlled cyclic loading tests as part of laboratory investigations. Such a methodology is utilized and reported in the present study for assessing the dynamic response of cohesionless sand obtained from River Palar, India. In order to assess the dynamic response and liquefaction potential of the cohesionless Palar sand, strain-controlled cyclic triaxial tests were performed on reconstituted cylindrical specimens prepared at relative density (Dr) of 35%. The specimens were subjected to varying effective confining pressure (50 and 75 kPa), shear strain amplitudes (0.3 and 0.8 mm). For all the tests, the frequency of the applied harmonic loading was maintained at 0.75 and 1 Hz. strain-controlled cyclic triaxial testing offers valuable scientific insights by providing a more realistic representation of earthquake loading. It allows researchers to isolate and study specific aspects of soil behavior crucial for understanding and mitigating liquefaction risks. The strain-controlled test reveals a reduction in the development of excess PWP with the increase in confining pressure, thereby indicating a decrease in liquefaction potential in the study area. There were no other studies on liquefaction potential analysis in the region's vicinity. The results indicated that the accumulated shear strains and excess pore-water pressures get significantly affected by the increase in confining stress and simultaneous changes in the strain amplitude.