桩锚支护中预应力锚杆锁定力损失分析及改进

Analyses loss of lock-stress on the prestressed anchor in the anchor-pile and technique improvement

针对石家庄地区深基坑中预应力锚杆实际受力与理论计算结果出入很大的问题,对某地下车库桩锚支护结构监测结果进行了分析。监测结果表明,在使用当地原有的工艺方法下,预应力锚杆锁定力损失很大,锁定后稳定拉力一般仅为100kN,仅为原设计值的1/2～1/3。而且长期观测来看,拉力增长不明显。本工程通过适当改进工艺和施工工具,大大降低了锁定力损失。

There were great difference between actual results of Shijiazhuang deep foundation pres- tressed anchor and theoretical calculations results, the retaining structure monitoring results an under- ground garage pile - anchor were analyzed. Montitoring results show that the loss prestressed bolt loc- king force is great by using of Native craft methods; the locked stable rally general is only 100kN, which is 1/2 to 1/3 of the original design value. The growth of rally is not obvious according to the long - term observation results. This paper greatly reduces the loss of the locking force through the ap- propriate technology and construction tools.