Development of dynamic load direct shear apparatus for frozen soils

The dynamic parameters of frozen soils is one of the important bases of engineering design, also the indispensable factor for the numerical calculation. The dynamic parameters directly affect the correctness of engineering design and numerical simulation. By analyzing the dynamic load triaxial test, and with reference to the structure of ordinary direct shear apparatus, Beijing Jiaotong University developed a new dynamic load direct shear apparatus. The apparatus used dynamic load actuator instead of the traditional direct shear apparatus's static load part, which can provide a 0.1-6 Hz, 0-20 kN dynamic load. Power systems, measurement and control systems of the dynamic load direct shear apparatus are analyzed; and the parameter selection of instrument frame, direct shear box, dynamic load actuators and so on are analyzed. Finally, by using the apparatus, a set of validation experiments have been carried out. The results show that the dynamic load direct shear apparatus can complete its purpose; stress-strain curve of frozen soils under dynamic loading can be measured, so as to open up a new way for determining kinetic parameters of frozen soils.