Thermo-mechanical behavior of normally consolidated soft Bangkok clay

Abstract

This paper presents the results of an experimental investigation on thermo-mechanical behavior of normally consolidated (NC) soft Bangkok clay specimen under drained and undrained heating conditions. The observed increase in the undrained shear strength of the specimen is due, in part, to the volume contraction induced by thermo-mechanical load and possibly from the permanent rearrangement of the soil fabric. An attempt was made to quantify the contribution of the soil fabric change to the total thermally induced shear strength increase. Without applying any thermal loading, an indirect procedure was developed to measure the contribution of soil fabric change to the increase in shear strength by inducing the average of the recorded volumetric change generated during drained heating-cooling test through mechanical loading. The experimental results show that the strength induced by mechanical loading alone only comprises 60% of the total developed thermo-mechanically induced shear strength increase. It is believed that the remaining 40% comes from the restructuring of the soil fabric activated due to thermal exposure up to 90°C.