To investigate the effect of temperature on mechanical parameters of a weak interlayer in water-saturated slope

the interlayer is regarded as a linear elastic body of coupled solid-liquid phase. A mechanical model for the thermal-pore water-mechanical interaction of the interlayer in water-saturated slope is established

and its coupling control equation is deduced.Using the physical similarity method

an experimental model similar to the slope prototype is established to study the variations of the inerlayer mechanical parameters caused by temperature. The proposed model is verified by comparing the theoretical results with the corresponding experimental results. It is found that the pore water pressure coefficient and thermal expansion coefficient are the key factors causing the increase of pore water pressure in the saturated interlayer. The pore water pressure coefficient depends on the compression characteristics of pore drainage and the solid medium. The larger the difference between these two compression characteristics

the larger the pore water pressure coefficient. Thermal expansion coefficient of pore water and thermal expansion coefficient of pore volume are the main factors affecting thermal pressure coefficient. A larger difference between them can result in a greater thermal pressure coefficient. Pore water pressure in the saturated interlayer slowly increases first and then dramatically increases with the increase of temperature

while the cohesion and shear strength of the saturated interlayer tardily decrease with the increase of temperature. Theoretical values of the saturated interlayer pore water pressure are in good agreement with the results from model test. Therefore

the proposed model can reflect the change characteristics of pore water pressure at different temperatures

which can provide some useful references to predict and control the stability of similar saturated slopes containing a weak interlayer.