武汉地铁隧道开挖引起地表沉降的数值模拟研究

NUMERICAL SIMULATION OF GROUND SUBSIDENCE DUE TO TUNNEL EXCAVATION FOR WUHAN SUBWAY

城市地铁隧道开挖引起过大的地表沉降会对隧道工程本身及地表建筑物造成危害。有效预计并合理控制隧道开挖引起的地表沉降具有重要的实践意义。以武汉地铁虎名区间隧道开挖工程为背景,运用有限元数值模拟软件MIDAS/GTS建立隧道断面开挖的数值模型,计算隧道开挖引起的地表沉降量,与实测沉降量进行拟合;根据隧道开挖过程中对应地表及临近建筑物的实际情况,优化开挖断面围岩预处理方案,建立优化后的断面开挖模型。模拟结果表明,优化后地表沉降仍在安全范围内,可以为类似工程沉降控制提供参考。

It has been well known that tunnel excavation of subway in urban area can cause ground settlement. Ex- cessive settlement would threaten safety of the tunnel itself and its surrounding buildings. Therefore, it will be of important practical significance to effectively predict and reasonably control this kind of subsidence. According to the excavation in Hu-Ming Section of Wuhan subway, the MIDAS/GTS software is used to build the model of the tunnel excavation. Surface subsidence caused by tunnel excavation is computed, and compared with the measured result. According to the situation of the corresponding ground and building during excavation process, the optimiza- tion of the preparative regimens on the surrounding rock excavation is carried out for building the optimization model of the tunnel excavation. The simulation results show the optimized surface subsidence is still in the safe range. The results would offer reference for similar projects in controlling the surface subsidence.