盾构下穿浅基础建筑的沉降规律分析

Analysis of Settlement of Buildings Induced by Shield Tunnels Under Construction

盾构施工会引起隧道周围土体变形,使地表已有建筑产生沉降和倾斜。针对太原地区汾河漫滩地层盾构下穿浅基础建筑物这一施工工况,比较FLAC3D模拟与现场监测两种方法得到的结果,分析建筑物存在与否以及建筑物刚度对于沉降规律的影响。结果表明:建筑物的存在对形成的横向沉降槽影响较小,但沉降过程与没有建筑物相比差别很大,建筑物的存在会约束周围土体,使建筑物及周围地层在沉降过程中表现出滞后性和整体性;建筑物刚度的改变对沉降滞后性的影响较小,刚度越大整体性越强。研究成果有助于盾构施工过程中建筑物及周围地层变形的预测。

Shield construction will cause soil deformation around the tunnel,and settle and tilt existing buildings on the ground.Aimed at the construction conditions of the flood plain stratum in Fenhe River and the shallow foundation building under the shield in Taiyuan area,this paper carried out the combination of 3D numerical finite difference software FLAC3D simulation and field monitoring to aualyze the in fluence of the existence and stiffness of buildings on settlement laws.The results show that the existence of building has a small effect on the formation of lateral settlement tank,the settlement process is very different with respect to the absence of buildings;The presence of buildings constrains the surrounding soil,and lead to the hysteresis and integrity in buildings and surrounding strata during settlement;The changes in building stiffness have less impact on settlement lag,and greater stiffness results in stronger integrity.The research results can help predict the deformation of buildings and surrounding strata during shield construction.