盾构掘进对浅基础建筑物的扰动及影响分区研究

Study on the Disturbance and Influence Zoning of Shield Tunneling on Shallow Foundation Buildings

软土地层中地铁隧道盾构掘进对上方建筑物的扰动效应明显。本文以典型软土地层为背景,模拟不同空间位置盾构下穿浅基础建筑物的扰动效应,分析地表沉降变化规律,探究盾构下穿独立基础、筏板基础、箱型基础建筑物的内力及变形特征,并基于复合准则和强度折减法研究了软土地层盾构下穿建筑物的影响分区。研究结果表明:建筑物沉降随隧道埋深的增加先增加再减小,在隧道埋深(H)=12 m时达到最大值;隧道埋深增加会导致建筑物的水平倾斜变小,最大倾斜值出现在H=6 m处;可将隧道衬砌及围岩的安全系数比值曲线突变点作为强、弱影响分区的界限。研究结果可为软土区盾构掘进对浅基础建筑物的扰动分析及影响区的划分提供参考。

The disturbance effect of shield tunneling on the upper buildings in soft soil is obvious.Based on the typical soft soil layer,simulate the disturbance effect of shield tunneling passing through shallow foundation buildings at different spatial positions.The variation law of surface settlement is analyzed.The internal force and deformation characteristics of shield tunneling under independent foundation,raft foundation and box foundation buildings are explored.Based on the composite criterion and strength reduction method,the influence zoning of shield tunneling under buildings in soft soil layer is studied.The results show that the building settlement increases first and then decreases with the increase of tunnel depth,and reaches the maximum when the tunnel depth(H)=12 m.The increase of tunnel depth will lead to the decrease of horizontal inclination of buildings,and the maximum inclination value appears at H=6 m.The sudden change point of the safety factor ratio curve of tunnel lining and surrounding rock can be used as the boundary of strong and weak influence zones.The research results can provide reference for the disturbance analysis of shield tunneling on shallow foundation buildings and the division of influence areas in soft soil area.