软土深基坑开挖对相邻地铁隧道影响控制研究

Study of deformation and displacement control of tunnels adjacent to deep foundation pit in soft clay

阐述了软土地区紧邻地铁隧道的深大基坑开挖过程中,地铁隧道产生位移的影响因素。结合工程实践,介绍了控制基坑围护变形、减小坑内外降承压水水力联系、动态设计的设计应对措施,并进行了有限元模拟计算、工程实测数据分析。计算及实测结果表明,通过采取基坑分区卸荷、坑内加固、钢支撑轴力伺服系统、加深止水帷幕,以及动态化设计、信息化施工等措施,可以有效将基坑围护变形及坑外地下水水位控制在允许范围内,进而保证基坑及地铁隧道安全,可为今后类似工程提供设计、施工经验。

This paper elaborates the influential factors of displacement of tunnels adjacent to deep foundation pit in soft clay.Based on project practice,this paper introduces the design methods to control deformation and displacement of foundation pit,and to decrease hydraulic connection of ground water in and out of foundation pit.This paper also introduces the dynamic design methods.FEM model is set up to simulate the whole excavation,and monitor data is analyzed.As the monitor data illustrates,methods like divisional unloading,support axial force system,soil improvement,waterproof curtain,dynamic design,information-guided excavation are of great value in tunnel deformation and displacement control,and ground water level control out of foundation pits,which consequently help ensure the safety of the project and the tunnels,and provide reference for similar projects.