Vol19 No.11: 3302-3313
【Title】A new numerical model of ring shear tester for shear band soil considering friction-induced thermal pressurization
【Author】ZHAO Neng-hao1; SONG Kun*2; ZHANG Rong-tang1; YI Qing-lin2
【Addresses】1 School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430023, China; 2 Key Laboratory of Geological Hazards on Three Gorges Reservoir Area (China Three Gorges University), Ministry of Education, Yichang 443002, China
【Corresponding author】SONG Kun
【Citation】Zhao NH, Song K, Zhang RT, et al. (2022) A new numerical model of ring shear tester for shear band soil considering friction-induced thermal pressurization. Journal of Mountain Science 19(11). https://doi.org/10.1007/s11629-022-7459-6
【Abstract】In this study, a new numerical model of ring shear tester for shear band soil of landslide was established. The special feature of this model is that it considers the mechanism of friction-induced thermal pressurization, which is potentially an important cause of high-speed catastrophic landslides. The key to the construction of this numerical ring shear model is to realize the THM (thermo-hydro-mechanical) dynamic coupling of soil particles, which includes the processes of frictional heating, thermal pressurization, and strength softening during shearing of solid particles. All of these are completed by using discrete element method. Based on this new model, the characteristics of shear stress change with shear displacement, as well as the variation of temperature and pore pressure in the specimen, are studied at shear rates of 0.055 m/s, 0.06 m/s, 0.109 m/s and 1.09 m/s, respectively. The results show that the peak strength and residual strength of specimen are significantly reduced when the mechanism of friction-induced thermal pressurization is considered. The greater the shear rate is, the higher the temperature as well as the pore pressure is. The effect of shear rate on the shear strength is bidirectional. The simulation results demonstrate that this model can effectively simulate the mechanism of friction-induced thermal pressurization of shear band soil during ring shear process, and the shear strength softening in the process. The new numerical ring shear model established in this study is of great significance for studying the dynamic mechanism of high-speed catastrophic landslides.
【Keywords】Ring shear model; Discrete element method; THM coupling; Frictional heating; Thermal pressurization