三峡船闸高边坡锚索预应力损失监测成果分析

Analysis of monitoring results of pre-stress loss in anchorage cables installed at high slope of ship-lock of Three Gorges Project

为了解三峡船闸高边坡预应力锚索的长期工作性能,根据73台锚索测力计累计达15 a左右的监测资料,对锚索预应力变化过程进行了统计分析,分别给出了锚索在锁定时以及锁定后截至2014年12月的预应力损失率量值及分布特点。同时,对锚索锁定后预应力损失率时序曲线进行了模式划分,并就不同模式下的发展规律进行了归纳与对比,指出以"急剧损失期、随机摆动衰减期、周期性平稳波动期"的3阶段发展模式最为典型。在此基础上,针对预应力变化的不同阶段,分析总结了损失原因和影响因素,并就预应力损失和边坡稳定性关系作了简要讨论。

In order to understand the long- term performance of the pre- stressed anchorage cables installed in high slope of ship- lock of Three Gorges Project,the statistical analysis on the pre- stress variation process was carried out on the basis of the15 years＇ monitoring data from 73 anchorage cables. The magnitude and distribution characteristic of the pre- stress loss at the locking moment and after the locking till December of 2014 are presented. The mode of the sequential curve of pre- stress loss after the locking are divided and the evolution laws under different modes are summarized and compared. The 3- stage pattern is the most representative,namely the abrupt spurt stage,randomly up- down attenuation stage and periodically stable fluctuation stage. The reason and influential factors of pre- stress loss are summarized in terms of different stages. The relationship between the pre- stress loss and the stability of slope is briefly discussed.