| The occurrence of landslides is mainly characterized by fast movement speed and large sliding volume,which makes landslide disasters have a serious i MPact on people's lives and the natural environment.Since the occurrence of the Vaiont landslide in Italy in 1963,many experts and scholars have focused on the formation mechanism and movement characteristics of high-speed landslides.At present,there are a variety of theories that can explain the high-speed sliding behavior of a sliding body.Among them,the thermal pressurization mechanism is one of the mainstream theories,that is,the friction and heat within the sliding zone cause the pore water to heat and expand,produce excessive pore water pressure,and lift up Body,so that the sliding body can achieve low-resistance high-speed sliding.However,in the process of landslide,there is a complicated coupling relationship among frictional heat generation in the sliding zone,pore water pressure change,and sliding body motion speed.There are many influencing factors,which bring difficulties to the research of thermal pressurization theory model.Based on the high-speed landslide friction pressurization model proposed by Cecinato,this paper comprehensively considers the spatial shape of the sliding body and the influence of the thermoplastic yield of the clay in the sliding zone on the landslide motion process,and establishes a pseudo two-dimensional thermoplastic yield-thermal-hydraulic-mechanical coupling high-speed landslide model.The simulation analysis of the Vaiont landslide case verifies the validity of the model.On this basis,the model control equation is applied to analyze the key parameters that affect the thermal pressurization process of the landslide,and the parameter characteristics that are easy to develop into a high-speed landslide are studied.Finally,the inversion simulation of the Jiufen Ershan landslide in Taiwan is carried out,and the important mechanism of its high-speed sliding is discussed.The main research work is as follows:(1)By establishing a quasi-two-dimensional thermal-hydro-mechanical coupled landslide model considering the thermoplasticity of clay,and relying on the case of Vaiont landslide,the evolution process of thermal pressurization and sliding promotion of Vaiont landslide,as well as the temperature and excess pore pressure in the sliding zone along the sliding surface,are studied.It also discusses the influence of clay thermoplastic yielding on the mechanism of thermal pressurization of landslides.A co MParative analysis with previous simulation results verifies the effectiveness of the model in simulating thermal pressurization of landslides.(2)Through the establishment of an infinite slope model,the influence of parameters such as landslide inclination angle,sliding body thickness,sliding zone thickness,thermal diffusion coefficient,hydraulic conductivity,clay material parameters and clay consolidation experimental constants on the mechanism of landslide thermal pressurization is studied,and the analysis is easy to develop It provides a basis for the parameter characteristics of high-speed landslides and provides a basis for the analysis of high-speed landslide disasters.(3)Taking the Jiufen Ershan landslide in Taiwan as the engineering background,a pseudo-two-dimensional thermal-hydro-mechanical landslide model considering the thermoplasticity of the clay is used to simulate the thermal pressurization process of the landslide,and the slider speed and the sliding zone at different sliding body positions are obtained.The evolution process of internal temperature and excess pore pressure is analyzed,and the mechanism of Jiufen Ershan landslide at high speed is analyzed,and co MPared with previous research results,the applicability of the model is verified. |
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