大型基坑群开挖对既有城市轨道交通区间隧道的影响及安全风险控制技术

The impact of large-scale foundation pit group excavation on existing urban rail transit interval tunnels and safety risk control technology

摘要

目前，基坑施工朝着“深、大”趋势发展，开挖范围大，并且通常需要采取降水措施，基坑开挖对相邻建(构)筑物的影响日益受到人们的关注。通过文献研究和数值模拟等方法针对大型基坑群开挖对既有城市轨道交通区间隧道的影响及安全风险控制技术进行了研究。首先，分析大型基坑群开挖的变形特征及其影响因素，总结了现有文献中相关案例和经验。其次，探讨了基坑开挖可能带来的安全风险，通过数值模拟计算出基坑开挖对既有城市轨道交通区间隧道产生的变形量，并针对性地提出采用地下连续墙+内支撑支护结构形式的风险控制技术和措施，以满足规范要求。结果表明：基坑群开挖对既有城市轨道交通区间隧道有一定的影响，但通过合理的安全风险控制技术可以降低潜在风险并保障隧道结构安全。研究结果为待建项目的安全设计和施工提供参考。

Abstract

At present, the foundation pit construction is developing towards the trend of “deep and large”, the excavation range is large, and precipitation measures are usually required, and the impact of foundation pit excavation on adjacent buildings(structures) has attracted increasing attention. The impact of large-scale foundation pit group excavation on the existing urban rail transit interval tunnels and the safety risk control technology are studied through literature research and numerical simulation. Firstly, the deformation characteristics and influencing factors of large-scale foundation pit group excavation are analyzed, and the relevant cases and experiences in the existing literature are summarized. Secondly, the possible safety risks of foundation pit excavation are discussed, the deformation of foundation pit excavation on the existing urban rail transit section tunnel is calculated through numerical simulation, and the risk control technology and measures in the form of underground diaphragm wall + internal support support structure are proposed to meet the requirements of the specification. The result show that the excavation of foundation pit group has a certain impact on the existing urban rail transit section tunnels, but the potential risks can be reduced and the safety of the tunnel structure can be guaranteed through reasonable safety risk control technology. The result of the study provide a reference for the safety design and construction of the project to be built.

关键词

大型基坑群 / 开挖影响 / 城市轨道交通 / 区间隧道 / 安全风险控制技术

Key words

large foundation pit groups / excavation impacts / urban rail transit / interval tunnels / security risk control technology

Author summay

孙 立(1983—), 男, 高级工程师, 硕士, 主要从事TOD 地下空间规划设计和运营管理研究。E-mail: [e-mail]