EFFECT OF CYCLIC STRESS RATIO ON THE LIQUEFACTION RESISTANCE OF FINE SAND IN SOC TRANG, VIETNAM USING CYCLIC TRIAXIAL TEST

Abstract

In the literature, the effect of different factors on the liquefaction resistance of sand has been widely investigated using the cyclic simple shear test or cyclic triaxial test. In which, the effect of CSR on liquefaction resistance significantly depends on the type of sand. In Vietnam, the sandy soils are widely distributed in coastal areas where many wind power farms are built and planned to build. Thus, the liquefaction resistance of sandy soil in these areas should be evaluated. In this study, the effect of cyclic stress ratio (CSR) on the liquefaction resistance of sand distributed in the coastal area of Soc Trang province, Vietnam will be evaluated for the first time using cyclic triaxial apparatus (Wykeham Farrance). The sand samples were prepared using the dry pluviation method with a relative density of about 56%. The stress-controlled method with CSR from approximately 0.1 to 0.35, the effective confining stress of 50 kPa, and the frequency of 1 Hz were applied. The research results showed that the axial strain and build-up of pore water pressure significantly depended on the range of CSR. In particular, this research has indicated the threshold of CSR for the liquefaction of sandy soil in this study area. Accordingly, under the testing conditions, sand samples were not liquefied with a CSR of less than 0.25.