泵站深基坑变形影响因素及其规律的有限元研究

Finite Element Study on Influencing Factors and Rules of Deep Foundation Pit Deformation in Pumping Station

武汉市江南泵站深基坑工程因工期被压缩,需优化原支护结构以满足要求。为确定优化支护结构,以深基坑围护桩的桩径、插入比和内支撑截面尺寸为因素,选取围护桩水平位移和基坑外地表沉降为分析基坑变形的指标,利用有限元软件ABAQUS模拟了武汉江南泵站的开挖支护过程,分析了各因素对深基坑变形的影响机理及其规律。结果表明:围护结构水平位移和基坑外地表沉降的显著影响因素为桩径和插入比,增加桩径和插入比能有效降低围护桩水平位移和基坑外地表沉降,插入比超过限值后对变形的影响趋于稳定。

Because the construction period of deep foundation pit of Jiangnan Pumping Station in Wuhan is compressed, it is necessary to optimize the original supporting structure to meet the requirement of construction period. In order to optimize the supporting structure, the pile diameter, insertion ratio and internal support section size of deep foundation pit retaining pile are taken as the factors, the horizontal displacement of the retaining pile and the surface settlement outside the foundation pit are selected as the indexes to analyze the deformation of the foundation pie, the finite element software ABAQUS was used to simulate the excavation and support process of Jiangnan pump station in Wuhan city, and the influence mechanism and rule of various factors on deep foundation pit deformation are analyzed. The results show that: pile diameter and insertion ratio are significant influencing factors of horizontal displacement and surface settlement of foundation pie, and increasing of pile diameter and insertion ratio can effectively reduce horizontal displacement of retaining pile and surface settlement outside foundation pit, but the influence of insertion ratio on deformation tends to be stable when it exceeds the limit value.