地铁施工对邻近管廊应力变形分析

STRESS AND DEFORMATION ANALYSIS OF ADJACENT PIPE GALLERY IN SUBWAY CONSTRUCTION

以邻近220 kV高压电力管廊的成都地铁30号线海桐街站施工为背景,采用FLAC 3D软件建立三维数值模型,模拟基坑开挖对管廊的应力变形影响,探讨了管廊变形对不同开挖步距、不同围护结构刚度的敏感性影响。研究结果表明:管廊的变形与轴力变化受基坑施工影响显著,最大变形区域与地层最大变形区域基本一致,在不同开挖步距、不同围护结构刚度的敏感性分析中,减小围护结构刚度,地下管廊水平位移明显增大,开挖步距对地下管廊水平位移的影响次之,而开挖步距对地下管廊竖向位移的影响可以忽略不计。分析结果可为后续管廊旁车站施工的周边管线变形控制提供参考。

Taking the construction of Haitongjie Station of Chengdu Metro Line 30 that is adjacent to a 220kV high-voltage power pipe gallery as an example,a 3D numerical model was established through the FLAC3D software,the impact of foundation pit excavation on the stress and deformation of the pipe gallery was simulated,and the sensitivity of pipe gallery deformation to the excavation step and enclosure stiffness was explored.Results show that the deformation and axial force changes of the pipe gallery are significantly affected by foundation pit construction,and the maximum deformation area is essentially consistent with the maximum stratum deformation area.In the analysis of the sensitivity to the excavation step and enclosure stiffness,the enclosure stiffness has the most significant impact on the horizontal displacement of the underground pipe gallery,followed by the excavation step.However,the impact of the excavation step on the vertical displacement of the underground pipe gallery can be ignored.The analysis results provide a reference for deformation control of pipelines around stations under construction.