上跨拟建隧道的地下综合管廊预保护效果

针对地下综合管廊上跨拟建地铁隧道施工的情况，为了减少盾构施工对管廊的影响，在地下综合管廊施工时采取对管廊结构的预保护措施. 采用分布式光纤监测盾构施工对管廊结构的影响，并采用数值模拟手段分析不同预保护方案下盾构施工对管廊竖向位移的影响. 监测和分析结果表明：设置坑底加固联合减沉桩的预保护措施能有效控制盾构隧道施工对地下综合管廊变形的影响，预保护效果显著. 采用坑底加固可以有效减小管廊两端位移差；减沉桩的布桩方式对管廊沉降控制效果有重要影响；双线盾构隧道施工导致的管廊最大沉降发生在双线隧道之间部位，避开盾构线路在单节管廊两端和双线盾构隧洞之间部位设置减沉桩对管廊的保护效果更佳.

Pre-protection effect of underground comprehensive pipe gallery over proposed tunnel

For the construction of the pipe gallery across the proposed subway tunnel, pre-protection measures for the pipe gallery structure were taken during the construction of the pipe gallery in order to reduce the impact of shield construction on the underground comprehensive pipe gallery. Distributed optical fibers were used to monitor the influence of shield construction on the pipe gallery structure. Numerical simulation method was used to analyze the influence of shield construction on the vertical displacement of the pipe gallery under different pre-protection schemes. Monitoring and analysis results show that the pre-protection measures of bottom reinforcement and anti-sinking piles can effectively control the influence of shield tunnel construction on the underground comprehensive pipe gallery, and the pre-protection effect is significant. The bottom reinforcement can effectively reduce the displacement difference between the two ends of the pipe gallery. The pile arrangement has an important influence on the settlement control effect of pipe gallery. The maximum settlement of the pipe gallery caused by the construction of the double-line shield tunnel occurred between the two lines. Better protection effect can be achieved by setting anti-sinking piles under two ends of single pipe gallery and between double-line tunnels, avoiding the path of shield tunnels.