Effects of Sampling Disturbance on Effective Strength Parameters of Soft Bangkok Clay

Abstract

This paper presents the effects of sampling procedure on undrained shear strength () and the effective stress parameter of soft Bangkok clay collected using Shelby tube in Bangkok, Thailand. The influential factors on the effective stress parameters of undisturbed samples, considered in this study, are the method of sampling, transportation and storage. These factors can cause a difference in effective stress parameters from in-situ conditions to laboratory condition. In order to obtain the effective stress associated with undrained shear strength () in laboratory condition, undrained compression test was conducted and during testing tensiometers were used to measure soil suction or negative pore water pressure. Field vane

shear test was used to measure the undrained shear strength () in in-situ state. According to the results it reveals that, when the Su value is modified using plastic index, undisturbed sample