西安地铁车站地下连续墙深基坑开挖变形分析

Analysis on the excavation deformation of the deep foundation pit of diaphragm wall in Xi’an metro station

以西安地铁6号线某车站深基坑工程为背景,基于开挖引起地面沉降理论,总结出主要影响区域,运用三维数值模拟支护结构变形和基坑附近地表沉降。结果表明:在距基坑边缘15 m范围内地表沉降变化量最大;开挖前期地连墙水平位移曲线呈现“悬臂式”变形,在坑底水平位移变形量达到峰值,在底板施工完成后变形量趋于稳定;地连墙嵌入15 m时最大变形位置大致在墙体的0.48~0.86 H,嵌入18 m时为0.53~0.81 H,强大的支护体系有效的抑制了基坑变形,最大程度减少施工对周围环境的干扰,保证了紧邻基坑重要文物建筑的安全性。

Based on the deep foundation pit engineering of a station of Xi ’an Metro Line 6 and the theory of ground settlement caused by excavation,this paper summarizes the main influence areas,and uses three-dimensional numerical simulation to simulate the deformation of supporting structure and the surface settlement near the foundation pit.The results show that the maximum change of surface settlement is within 15 m from the edge of the foundation pit.The horizontal displacement curve of the ground wall presents "cantilever" deformation in the early stage of excavation,the horizontal displacement deformation reaches the peak at the bottom of the pit,and tends to be stable after the completion of the floor construction. When the ground wall is embedded 15 m,the maximum deformation position is approximately 0.48~0.86 of the wall,and 0.53~0.81 of the wall when embedded 18 m. The strong support system effectively suppressed the deformation of the pit,minimized the interference of the construction with the surrounding environment,and ensured the safety of the important cultural relics buildings in the immediate vicinity of the pit.