地铁盾构施工对挹江门城墙安全性的影响分析

Safety Analysis on Yijiangmen City Wall Impacted by Metro Shield Tunneling Construction

南京地铁5号线采用盾构施工方式下穿通过挹江门城墙,结合挹江门城墙结构现状及盾构隧道的埋深和走向,采用规范经验公式及数值模拟法就地铁盾构施工对城墙安全性影响进行评估分析。根据计算分析,地铁盾构施工会引起城墙产生一定程度的不均匀沉降现象,会在城墙局部位置产生拉应力,可能会引起城墙局部位置发生开裂。以上评估结果可以为相关单位采取对挹江门城墙保护及监测措施提供参考。此外,规范及数值模拟方法计算结果存在一定程度差异,但尚属于同一数量级。两种计算方法需要结合工程特点进行选用,必要时可以对计算结果相互验证。

Nanjing Metro Line 5 passes below the Yijiangmen city wall,which is constructed by tunnel boring machine(TBM).Based on the current status of Yijiangmen city wall structure,the buried depth and trend of TBM,analysis of the impact on the safety of Yijiangmen city wall by TBM construction was evaluated and analyzed by standard empirical formula and numerical simulation.According to the results of calculation and analysis,TBM construction will cause uneven settlement of Yijiangmen city wall.Tensile stress occured in some local position of the wall,and cracking may occur in some local position of the wall.The above evaluation results can provide reference for relevant administrative agencies to take measures to protect and monitor Yijiangmen city wall.There are some differences in the results of the specification and numerical simulation which havethe same order of magnitude.The two calculation methods need to be selected according to the engineering characteristics,and the calculation results can be verified each other when necessary.