Vol. 2, Issue 2, Part H (2016)

Abstract
Liquefaction is a soil behaviour phenomenon in which a saturated fine and medium sandy soil loses a substantial amount of strength due to abrupt increase in pore water pressure and leads to decrease in effective stress during strong ground shaking. Liquefaction may cause failure of foundations, resulting in collapse of structure, even if the structure is designed as an earthquake-resistant. Liquefaction depends on characteristics of subsurface soil. Subsurface characteristics can be evaluated from Standard Penetration Test (SPT). Krishna District is an important District in Andhra Pradesh, India. The construction activities in the district are rapidly increasing. It is essential that the new structures in Krishna District should be analyzed for Liquefaction susceptibility. In the present investigation an attempt has been made to determine the liquefaction susceptibility of various sites in Krishna District of Andhra Pradesh State, India based on in-situ SPT. The analysis is carried out on simplified method as proposed by Seed and Idriss (1971). It was found from present study that factor of safety against liquefaction falling less than 1 for most of the sites in Krishna District when magnitude of earthquake above 6.