刚柔性长短桩复合地基工程特性有限元分析

以邢衡高速公路一期工程为例，采用数值模拟的方法，对高速公路路基下刚柔性长短桩复合地基的桩土应力比和沉降变形的变化规律进行了研究。研究结果表明:桩间距、柔性桩桩长、下卧层土体变形模量对桩土应力比的影响较小，适当提高柔性短桩变形模量可增加柔性短桩的荷载分担比；适当减小桩间距和提高柔性短桩变形模量可在一定程度上减小路基的沉降变形；下卧层土体的变形模量对路基的沉降变形影响较大。

Finite Element Analysis of Engineering Characteristics of Composite Foundation with Rigid-flexible and Long-short Piles

Using the method of numerical simulation, XingHeng-Xingtai Expressway Phase I is exampled to research the change rule of pile-soil stress ratio and settlement of composite foundation with rigid-flexible and long-short piles under expressway subgrade. The results show that, the pile spacing, length of flexible pile and the deformation modulus of soil in substratum have little effect on the pile-soil stress ratio. Improving the deformation modulus of flexible pile properly can increase the load sharing ratio of flexible short piles. Decreasing the pile spacing and improving the deformation modulus of flexible pile properly can reduce the settlement of subgrade to some extent. The deformation modulus of soil in substratum has great influence on the settlement of embankment.