Study On The Dynamic Direct Shear Characteristics Of Warm Frozen Soils

ABSTRACT:Permafrost has special thermal and mechanical properties and physical properties, frozen soil kinetic parameters under seismic loading also has its particularity, thus the dynamics parameters of frozen soil under seismic load is a key problem, because the warm frozen soil is more sensitive, its dynamic parameters is an important part of the frozen soil dynamics research.This paper summarizes and analyzes a large number of domestic and foreign study of dynamic characteristics of frozen soil under dynamic load of situation, on this basis, based on the stress-strain characteristics of frozen soil dynamics and kinetics parameters of research methods, a series of dynamic load direct shear tests were carried out using the dynamic load direct shear test apparatus which is independent designed by the geotechnical laboratory in Beijing jiaotong university.Testing for the clay subgrade filling in ha shen section of Harbin-dalian passenger dedicated line, this paper studies the soil dynamic stress features under different control parameters (temperature, normal stress, loading amplitude, etc.), it also analyses and summarizes the rule of stress and strain change over time of high temperature frozen soil under dynamic load, it is concluded the stress-strain hysteresis curve, then calculated the values of both dynamic shear modulus and dynamic damping ratio,5and summarizes out the rule of dynamic shear modulus and dynamic damping ratio changing with different parameters,such as the temperature, normal stress, loading series.In this paper, the using of dynamic load direct shear apparatus provides a new choice for the determination of kinetic parameters of permafrost.