深基坑桩锚支护体系桩身内力及变形监测分析

Monitoring and Analysis on Internal Force and Deformation of Soldier Piles in Anchor Bracing Structure for Deep Foundation Pit

依据西安市高新区某桩锚支护式深基坑支护桩内力和侧向位移的监测数据,对支护桩桩身内力与变形的变化规律进行了对比分析,得到了桩身弯矩和位移沿深度方向的分布。分析结果表明:随着基坑开挖深度的增加,支护桩的桩身弯矩值以及桩身向基坑内侧方向的位移不断增加,桩身弯矩最大值出现在基坑开挖底面以下,反弯点沿桩身向下移动。锚索锁定后对桩身内力与位移的作用显著,减小了桩身弯矩,限制了桩身位移的增加;空间效应在基坑开挖过程中,对桩身内力与位移产生影响,基坑中间支护位置桩身的最大弯矩值与位移值明显大于其他支护位置,分析结果可对基坑的进一步施工提供参考。

According to the monitoring data on the internal force and deformation of soldier piles in anchor bracing structure for deep foundation pit in High-tech Zone, Xian, the variation rule on internal force and deformation of soldier piles is compared to obtain distribution of pile bending moment and displacement in depth direction. As a result, it is shown that the bending moment and displacement toward to pile inner is increased with the increase of excavation deep, the pile bending moment is maximum under the excavation surface of the foundation pit, and point of inflection moves down along the pile. The anchor cable has significant effect on the internal force and displacement of solider piles after locking, reduces the pile bending moment and limits the increase of the pile displacement; space effect had influence on the internal force and displacement of pile during excavation, and the pile in the middle of the foundation pit has higher maximum bending moment and displacement than the piles in other position. The analysis results provide reference for the further construction of the foundation pit.