桩体刚度对复合地基支承路堤失稳破坏模式的影响研究

在已有研究基础上,对理想塑性、脆性拉裂两种破坏后性状对应桩体的抗弯、抗剪承载力的进行了分析比较,脆性拉裂破坏后性状可以更好地反映桩体弯曲破坏后抗弯及抗剪承载力的降低。对于复合地基支承路堤的有限差分数值模拟表明,路堤荷载、桩体材料弹性模量不同时桩体受力以及路堤失稳时桩体的破坏模式并不相同,当桩体弹性模量、路堤荷载较大时,桩体发生受拉弯曲破坏,需考虑桩体的脆性拉裂破坏后性状以描述桩体抗弯、抗剪承载力的降低以及不同位置桩的连续破坏。

Influences of stiffness of piles on failure modes of embankment of composite foundation

The post-failure simulations of ideal elastic-plastic and brittle cracks are adopted to analyze the bearing capacities of piles based on the existing researches. The weakening of flexural and shear capacities when cracks are generated can be better reflected by the brittle crack model. A finite difference method is adopted to analyze the stability of pile-supported embankment. The analysis reveals the failure modes of piles are different under different elastic moduli of materials and embankment loads. When the stiffness and strength of piles reach a certain value, bending-tensile failure happens. The brittle crack model should be used to describe the weakening of the flexural and shear capacities of piles as well as the progressive failure of different piles.