盾构隧道上方卸载对结构收敛影响及控制指标研究

Study on influence of unloading at the top of shield tunnel on architecture convergence and control index

地铁盾构区间上方外部项目卸载工程施工极易造成地铁结构变形,目前,地铁的设计、施工验收、运维、安全保护等规范中的变形技术指标要求尚未统一。因此,亟需明确地铁结构极限承载力下的极限变形控制值、准永久组合荷载下的结构正常使用变形控制值、在地铁结构设计-施工-养护及安全保护所构成的全寿命周期考虑下的外部项目及地铁运维的总变形控制值及安全富裕度。文章以深圳地铁6号线支线某盾构区间上部卸载项目为依托,采用荷载-结构法计算盾构隧道上方荷载改变导致理论计算结构内力改变及收敛变形,并结合实际监测结果分析地铁结构健康度收敛与变形控制指标,得出地铁结构服役状态和后期变形指标,为地铁运维及安保区外部项目收敛变形控制值要求提供借鉴。

In order to define the ultimate deformation control value under the ultimate bearing capacity of the metro architecture,the deformation control value under the normal use of the architecture under the quasi-permanent combined load,and the total deformation control value and safety margin of external projects and metro operation and maintenance under the consideration of the full life cycle consisting of metro architecture design construction maintenance and safety protection,based on an unloading at the top of shield tunnel section project on the branch line of Shenzhen metro line 6,this paper adopts the load-structure method to calculate.In view of the theoretical calculation of architectural internal force change and deformation convergence caused by changing the load at the top of shield tunnel,combined with the actual monitoring results,it analyzes the metro architecture health convergence and deformation control indicators,obtains the metro architecture service status and late deformation indicators.