对既有建筑下盾构穿越施工引起的地表沉降规律进行多工况系统的3维数值模拟研究,认为在地层及隧道相关参数不变的情况下,既有建筑与隧道的相对位置、既有建筑的刚度、自重等对地表沉降规律具有明显的改变作用,主要表现为对沉降量、沉降槽宽度及形式等的改变.结合上海轨道交通11号线穿越历史保护建筑上海市徐家汇观象台工程,建立全3维模型对既有建筑下盾构穿越施工全过程进行模拟,预测地表沉降量.通过对穿越过程沉降测点的监测,对数值模拟预测的合理性进行了验证.
A series of 3D numerical simulation about the shield tunnel undercrossing existing building was accomplished.Results show that important parameters include relative position of tunnel and existing building,weight and stiffness and geometric form of existing building have dominating influence on the pattern of surface settlement trough,especially in changing the maximum settlement and modifying the width and form of settlement trough.Based on the Shanghai Metro Line 11 undercrossing the historic building-Xujiahui Observatory,full three-dimensional model about shield tunnel undercrossing Xujiahui Observatory was established to simulate construction process.Settlements of surface were forecasted.Measuring points were arranged to monitor surface settlements during undercrossing to verify simulation results.