封闭作用对软土地基上桥台桩基的影响机理分析  

Mechanism Analysis of Abutment Pile Foundation on Soft Ground Affected by Closure Effect

作　　者：问延煦[1] 蔡霞[2] 

机构地区：[1]江苏省交通科学研究院,南京211112 [2]解放军理工大学,南京210007

出　　处：《土工基础》2009年第5期43-46,共4页Soil Engineering and Foundation

摘　　要：封闭作用会使软土层在较大范围内产生超常的水平向应力,在桥头段将使得桥台下桩基受到侧向推挤。利用离散元程序(PFC2D)建立了力学模型,对某工程桥头路段实例进行深入的机理分析,发现当桥台台帽自由时,其水平向附加应力沿深度方向的分布呈现中部大、两端小的特点,同时指出硬壳层对下卧软土层的封闭作用是导致事故发生的主要原因,为工程设计人员处理类似地基提供借鉴。Excess horizontal stress could be produced in soft ground by closure effect, which causes the nearby abutment pile foundation to deform laterally. PFC^2D is used to establish a mechanic model. By analyzing, it is concluded that horizontal stress gets its top point in the middle of pile, while appears to be low at the top and the bottom if the cap of the abutment is free, and the damage of the piles is caused mainly by the closure effect. It also could be taken as an example for similar problems.

关 键 词：硬壳层 封闭作用 桥台桩基 地基处理 

分 类 号：TU473[建筑科学—结构工程]