刚柔复合抗滑桩受力与变形特性数值模拟分析

Numerical analysis of mechanical and deformation characteristics of composite rigid-flexible anti-slide pile

基于某高速公路路堤边坡支挡工程,采用有限差分软件FLAC3D分别建立普通刚性抗滑桩和刚柔复合抗滑桩加固边坡的三维数值模型,对比分析两种抗滑桩结构的受力与变形特性,进而探讨柔性材料厚度、柔性材料弹性模量及抗滑桩弹性模量等关键设计参数对刚柔复合抗滑桩受力与变形特性的影响.研究结果表明:与普通刚性抗滑桩相比,刚柔复合抗滑桩可以明显减小桩身弯矩、剪力及桩侧土压力,但会在一定程度上增大桩身自由段和填土的水平位移;增大柔性材料厚度可在一定范围内减小抗滑桩内力和桩侧土压力,但减小程度有限,柔性材料弹性模量对抗滑桩受力特性影响较小;适当减小抗滑桩的弹性模量可以明显降低抗滑桩内力.

A three-dimensional numerical model of slope reinforced by the ordinary rigid anti-slide pile and the composite rigid-flexible anti-slide pile （CRAP） was established respectively based on a slope retaining project, which was used in a expressway embankment. The mechanical characteristics and deformation of two different kinds of structures were compared and analyzed by using finite difference software FLAC^3D. Furthermore, the influences of several key design parameters, including the thick- ness and the elasticity modulus of flexible material, the elasticity modulus of rigid pile, on the me- chanical characteristics of the CRAP were investigated. The results show that compared to the ordina- ry rigid anti-slide pile the CRAP is more effective in reducing the bending moment, shear force and lateral earth pressure of the pile with partly increasing horizontal displacement of the gravel filling and the pile segment above the slip surface. The internal force of the pile decreases in a limited extent as the increase of the thickness of flexible material. The elasticity modulus of flexible material has a little effect on mechanical characteristics of the CRAP while reducing the elasticity modulus of the rigid pile could reduce its internal force significantly.