Numerical Model Test Of Dynamic Pile-Soil Interaction In Frozen Soils Under Horizontal Load

ABSTRACT:Permafrost regions distribute widely, especially, in the Northeast, Northwest and Qinghai-Tibetan. Permafrost regions are in frequent earthquake areas. Pile foundations are the main construction foundation in permafrost regions. There is little research data or achievement at home and abroad about dynamic pile-soil interaction in frozen soils. For this reason, this study has significant meaning.Based on frozen-soil direct shear test and pile-frozen soil dynamic interaction model test, dynamic behaviors of pile foundation are analyzed by numerical simulation. They offer parameters of frozen soil. Pile-frozen soil dynamic interaction model test supplies comparison data for numerical simulation. The article established three-dimensional dynamic interaction analysis model of pile-frozen soil by Finite-difference procedures, and the response of the pile and soil around pile in the level of harmonic loads were examined. The main conclusions are as follows:(1) The shear strength parameter of frozen soil is much bigger than usual soil; When temperature decreased, cohesion and the shear strength increased significantly and friction increased lightly; The alternation tendency of static and dynamic parameter is accordant, and the dynamic parameter is much bigger than the statics parameter;(2) The results of the calculation show minor differences compared with the experiment data available (less than 15%).(3) Internal force and displacement history curves of pile show sine profile under lateral harmonic load; Internal force and displacement of pile and soil around pile fall gradually along the vertical and horizontal direction; When the displacement is smaller, the dynamic rigidity slowly decreases with the top displacement increasing, and when the displacement is larger, it rapidly lessens and tends to vary gently over time at last;(4) The dynamic response of pile increases with the load adding and temperature rising; Shear-displacement curve of pile head show oval-shaped which contracts in the middle because of separation between pile and soil.