桩承加筋式路堤的承载机理研究

Mechanisms of Load Transfer in Geosynthetic-Reinforced Pile Supported Embankment over Soft Soil

具有深厚软弱下卧层的路堤可采用桩承加筋式复合地基,以提高地基的承载力、减小路堤总沉降和差异沉降,而且可以布成疏桩,提高桩土荷载分担比,降低工程成本,在国内外的应用越来越广泛。本文采用拉格朗日描述位移的大变形有限元分析方法,研究桩承加筋式路堤的荷载通过土拱效应和拉筋材料传递到桩身的机理和变化规律,及其受路堤填筑高度、桩身刚度和桩间距、路堤填土的工程性质、拉筋材料抗拉刚度和铺设位置的影响性状。通过数值分析,得到一些有助于桩承加筋式路堤设计的结论。

The geosynthetic reinforced pile-supported （GRPS） subgrade may be constructed for embankments over deep weak soil strata to improve the bearing capacity of the subgrade bed, reduce total and differential settlements, enhance the efficiency of transferring the load from the soil to the piles, and reduce the construction cost. Finite element analysis with updated mesh technology is used to study the mechanism and behavior of load transfer of the GRPS embankment, which is a combination of soil arching effects in fill and the stiffened geosynthetic-aggregate platform. The influence of the design parameters on GRPS embankments is studied in detail, the design parameters include the embankment height, property of fill construction, pile spacing, pile module of rigidity, geosynthetic tensile stiffness, and position of the geosynthetic reinforcement. Some conclusions of the numerical analysis are helpful to the design of the GRPS embankment.