桩-土水平相互作用的颗粒流数值研究-《深圳大学学报理工版》

文章信息/Info

Title:: Numerical study on lateral soil-pile interaction by particle flow code

Author(s):: SU Dong¹ ; LI Xia² ; and LI Xiang-song²; 1)College of Architecture and Civil Engineering,Shenzhen University Shenzhen 518060 P. R. China
2) Civil Engineering Department Hong Kong University of Science and Technology, Hong Kong P. R. China

Keywords:: numerical modeling of particle flow ; soil-pile interaction; orthogonal loading effect; non-coaxial

摘要:: 对水平载荷作用下的桩-土相互作用问题进行颗粒流数值模拟和研究. 应用PFC2D程序, 模拟了直线单调、直线循环、十字和半圆形加载路径下桩-土相互作用过程. 并通过对加载过程中土的细观物理量的考察, 研究土的细观力学特征和桩-土相互作用宏观力学行为之间的相互联系. 研究结果表明, 垂直方向的预加载会引起土阻力的退化, 产生“垂向加载效应”;而在非直线加载路径下, 随着位移的增加, 载荷的增量方向会逐渐偏离位移的增量方向, 出现不共轴的现象. 数值试验观测到的现象和机理可为物理模型试验的进行提供积极的指导作用.

Abstract:: Numerical modeling of soil-pile interaction under lateral loading was performed by Particle Flow Code in two dimensions, loading paths of which include monotonic, periodic, cross and semicircular paths. Force-displacement relationships were measured while their connections with microscopic soil behavior were studied by monitoring variations of some physical quantities. The numerical simulations show that the preloading along the orthogonal direction would cause stress degradation in soils and induce orthogonal loading effect. Under nonlinear loading path, the direction of load increment deviates gradually from the direction of displacement increment as the displacement increases. The phenomena and corresponding mechanisms obtained from numerical tests benefit design and implementation of physical model tests.