地铁车站顺行密贴下穿既有隧道安全风险评估
Safety risk assessment of paralled and closely-attached metro station under-passing existing subway tunnel

摘要 借鉴已有的穿越工程安全风险评估手段，引入肯特法安全风险评估技术，从工前检测、工前评估、工中动态控制及工后评价4个方面入手，建立了适用于新建地铁顺行密贴下穿既有隧道结构的安全风险评估体系.通过工前检测和工前评估可以精准地掌握既有隧道结构的服役状态并确立合适的施工期间允许变形控制值；工中动态控制实时地反映了既有结构的变形情况，是该评估体系的重中之重；工后评估突出施工结束后对既有结构的检测及监测，以图评价整个施工过程对既有结构造成的影响.将该成果应用于新建北京地铁15号线奥林匹克公园站顺行密贴下穿大屯路隧道施工过程中，结果表明，穿越工程安全风险控制达到了预期的控制目标，确保了大屯路隧道在隧道施工过程中的安全运营.
Abstract：The existing safety risk assessment methods for crossing engineering and Kent safety risk assessment techniques are introduced and used. This paper establishes a safety risk assessment system for the construction of a newly built subway station which under passes existing tunnel structure, which is based on four aspects：the service state detection of existing tunnel structure, pre-construction evaluation, dynamic control during the construction and post-construction evaluation. The service state detection and the pre-construction evaluation can be used to get the accurate service state of existing structures and the appropriate allowable deformation control value during the construction can be ascertained; dynamic control during construction is the most important part of the evaluation system, it can be used to reflect the deformation of the existing structure in real time; the aim of post-construction evaluation is to evaluate the influence of the whole construction process on existing structures through the detection and monitoring of existing structures after construction. The conclusion of this paper is applied in the engineering where Olympic Park station of Line 15 Beijing Subway closely attaches to the Datun-Road tunnel. According to the result analysis, the desired control goal has been achieved so that the safely operation of existing tunnel has been realized during the construction.