高砂水电站8号坝段稳定性分析

Stability Analysis of Block 8 of Gaosha Hydropower Dam

高砂水电站8号坝段坝基下存在一层全~强风化夹层,施工时虽已作工程处理,但仍是地质条件最复杂、岩性最差的坝段。目前水电站运行已超20年,从坝基存在的泥化夹层情况分析,该坝段坝基岩可能存在基岩软化、泥化夹层泡水软化及渗透破坏的可能性,对坝基稳定不利。近年监测数据显示,大坝坝顶变形、坝基扬压力变化总体稳定。通过定性定量分析、统计模型法对监测数据进行分析,了解到8号坝段的实际运行性态无异常,同时结合大坝稳定性复核计算成果,判断该坝段不存在稳定问题。

A layer of full~intensive weathered layer is existing under the block 8 dam foundation of Gaosha hydropower dam.Although engineering treatment,it is still the dam block with the most complicated geological conditions and the worst lithology.At present,the hydropower station has been in operation for more than 20 years.Based on the analysis of the pelization band existing in the dam foundation,it is found that there may be softening of bedrock,softening of pelization band by water bubble and seepage failure,which is detrimental to the stability of the foundation.The monitoring data in recent years show that the deformation of the dam crest and the change of the uplift pressure of the dam foundation are generally stable.Through qualitative and quantitative analysis and statistical model analysis on the monitoring data,it is found that the actual operation behavior of block 8 is normal.And combining with the results of dam stability check calculation,it is judged that the dam section does not have stability problems.