浅埋大跨隧道下穿建筑物群的施工期安全风险管理

梧村隧道大跨度浅埋暗挖段下穿密集建筑物群,地质条件和环境十分复杂,施工难度极大。针对建筑物不均匀沉降和变形破坏的风险,制定了较为完善的安全管理措施。采用数值模拟方法,对施工开挖、支护进行精细化模拟,得出关键施工步序的变形量;结合类似工程经验和规范,制定安全监测的控制标准,以指导监测和施工。开展全面的监测,掌握隧道施工过程中建筑物、管线、地面以及地层、隧道围岩和支护结构的动态变化,并对关键的建筑物实施24h自动化监测。建立了先进的安全管理网络传输系统,包括监测信息管理、预测预报系统和LED显示屏信息发布系统,将所有监测信息和施工动态存储入数据库服务器中,供联网的计算机检索查询。以第三方监测单位为主,建立报警及监测工作III级管理措施,并及时将报警信息及工程近况以文字和图形方式发布在LED显示屏上,供参建各方知晓。

Construction security risk management for shallow-buried large-span tunnel passing intensive buildings underneath

The Xiamen Wuchun highway tunnel of which the span is 34.5 m and only 9 m buried depth, passing underneath an area over 95 sets of buildings within it, the geological condition and environment of the tunnel is very complicated; and the degree of difficulty being under construction is immense also. In order to solve the main security risks during tunnel construction, such as uneven settlement, deformation and destruction of building, we conducted comprehensive research approaches and adopted a set of comparatively perfect safety management system. Firstly, we simulated excavation and reinforce of tunnel construction by using numerical method, and get the deformation values on key construction step. Combining with experiences from other similar projects and national standard, we drew out the control standard values for security monitoring to guide the tunnel excavation and the building protection. Secondly, we carried out thoroughly monitoring to grasp the dynamical response of building, pipeline, ground surface, stratum, surrounding rock and lining of tunnel during construction to ensure security, and implement 24 h automatic monitoring to the key buildings. Thirdly, having built advanced network transmission system of security management, which include monitoring information management, forecasting system and the information announces system with LED display screen; the whole monitoring data and construction proceedings can be stored and processed in data base server, while can be browsed and inquired by the networked computer. Finally, based on the work of third-party monitoring, we built a kind of monitoring management system of III levels warning, which can announce the warning information and construction proceeding to all participant via intranet or LED screen in time.