软土地基双排桩基础悬臂式挡土墙受力变形的现场测试及数值模拟分析

Field Test and Numerical Simulation of Cantilever Retaining Wall Using Double-row Piles on Soft Soil Foundation

以成渝(成都—重庆)高速铁路内江北车站双排桩基础悬臂式挡土墙工程为例,建立三维数值模型并结合现场测试研究双排桩基础悬臂式挡土墙结构内力与变形特性,分析结构高宽比、软土厚度对结构稳定性的影响。结果表明:结构变形以水平变形为主,其中桩基变形占比较大,最大水平位移发生在悬臂式挡墙顶端;结构于桩顶、桩基锚固点处、底板连接处出现应力集中,设计时应对这些部位进行强度检算。建议结构设计高宽比取1. 6～2. 0,并根据线路的变形控制指标与地基情况采取合适的软土加固措施。

The engineering background is Neijiang North Station of Chengdu-Chongqing high speed railway. A three-dimensional numerical model was established for a cantilever retaining wall using double-row piles on soft soil foundation.Field test was also conducted.Through the study of the structural inner force and deformation,the effects of the ratio of height to width and the depth of soft soil on the structural stability were analyzed.The results show that the lateral deformation is the dominant structural deformation.In particular,the deformation of the pile is signif icant.The maximum lateral deformation is at the top of the cantilever retaining wall.Stress concentration occurs at pile top,anchor point of pile foundation,and joint of bottom plate. T hus,strength check should be carried out at these locations. It is recommended that the ratio of height to width should be 1. 6 through 2. 0. According to the deformation control index of the line and the foundation situation,the appropriate soft soil reinforcement measures are suggested.