湖底深基坑围护结构变形与受力特性研究

基坑围护结构是基坑安全的重要保证。通过三维有限单元模拟,考虑地下水渗流的影响及结构与土体之间的相互作用,对某湖底明挖隧道基坑支护结构在施工过程中的变形和受力变化规律进行研究,并与现场监测结果进行对比验证。结果表明:围护结构的不同部位对基坑开挖的响应规律并不一致;水平向支护结构受开挖影响,向坑内倾倒,竖直向桩体随开挖应力重分布影响中段发生弯曲变形,总体稳定。模拟变形结果与监测结果较为一致,验证了基坑围护结构的有效性和模拟计算的准确性。研究结果为基坑后续施工提供了参考依据。

Study on Lakebed Deep Foundation Pit Bracing Structure Deformation and Weighted Features

The foundation pit bracing structure is an important guarantee for foundation pit security.Through 3D finite element simulation,considering impact from groundwater seepage flow and interaction between bracing structure and soil mass have carried out study on foundation pit bracing structure deformation and weighted variation pattern during the construction process of an open cut tunnel in lakebed as well as comparison and verification with site monitoring results.The result has shown that the different positions of bracing structure have different response regularities during foundation pit excavation.Impact from foundation pit excavation,the horizontal bracing structure will be toppled to the pit,while the middle segment of vertical pile will be bending deformed from excavation stress redistribution,but overall stable.The simulated deformation result is more consistent with the result from monitoring,thus verified the effectiveness of bracing structure and accuracy of simulative computation.The studied result can be reference for subsequent foundation pit construction.