Temperature effect on the undrained strength and stress–strain responses of saturated silt

This paper presents an experimental investigation on the undrained strength and stress–strain response of saturated silt using a temperature-controlled triaxial apparatus. A series of consolidated undrained triaxial compression tests were performed on saturated silt. Prior to shearing, the normally consolidated specimens were heated or subjected to a heating–cooling cycle in a temperature range of 20–60 °C. The undrained stress–strain and excess pore pressure responses at various consolidation pressures and temperatures are analyzed. The effects of heating and heating–cooling cycle on undrained strength are emphasized. The temperature effect on the phase transformation behavior and critical state is revealed. The results show that (1) the Nanjing silt presents an obvious phase transformation behavior, which is affected by temperature. A unique critical state line at various temperatures can be observed; (2) the undrained strength is increased by heating and heating–cooling cycle. The normal consolidated silt exhibits dilation behavior and hardening stress–strain response; (3) the pore pressure is accumulated by an undrained heating–cooling cycle, and it nonlinear increases with temperature; (4) the change of normalized undrained strength relies on the overconsolidation ratio (OCR) and temperature.