某地铁深基坑支护体系内力与变形监测结果分析

对某地铁深基坑支护结构内力与变形监测结果进行了分析。监测结果表明 ,施加的锚杆预应力有 10 %～ 2 5 %的损失 ,在开挖过程中锚杆轴力有一定程度的增加 (约 10 %左右 )。钢支撑的轴力随开挖深度的增加而增加 ,轴力大小变化与基坑开挖方式、速度及下层支撑的逐一拆除有关。支护桩体的变形随桩深、支撑条件变化而变化。基坑顶部的水平位移以坑壁中央最大 ,靠端部位移较小。

ANALYSIS OF MONITORING RESULTS OF INTERNAL FORCE AND DEFORMATI ON OF SUPPORT SYSTEM FOR A SUBWAY DEEP EXCAVATION

The monitoring results of the internal force and displacement of support structure for a subway deep excavation are analyzed.The prestress loss of the anchor is in the range of 10%～25%,with about 10% increase in the axial force of the anchor during the construction.The axial force of steel prop increases with the increment of the excavation depth.And the value changes with the variety of excavation mode,velocity and dismantlement of the underlying props in order.The horizontal displacement of the retaining pile body is related to the pile depth and supporting condition.The deformation of the earth surface is the largest in the middle and the smaller at the end.