白龙江宝珠寺水库库区塌岸模式研究

Study on Bank Collapse Pattern of Baozhusi Reservoir on Bailongjiang River

通过对宝珠寺水库库区塌岸情况的现场调查及其典型塌岸区的工程地质测绘,查明了其塌岸主要发生在第四系残坡积及古滑坡堆积体库岸的规律;建立了库区塌岸的3种主要模式:冲刷塌岸型,蠕动-张裂变形,牵引式滑移-拉裂错落;重点剖析了各模式典型塌岸段的形成发展过程及机制,计算分析出不同水位下的典型滑坡的稳定性变化规律;统计得出冲刷塌岸后各类岸坡的水上稳定坡角、水下磨蚀坡角;最后,阐明了水库岸坡的地层岩性及地质构造条件是塌岸发生的内因,而水库水位消落时岩体中排水不畅所形成的滞后的动水压力,是使滑坡及土体发生蠕动的外因。

According to the investigations of Baozhusi Reservoir＇s bank collapse and geological survey of typical bank collapse,the characteristics of bank collapse distribution are obtained. It is found that collapses mainly occur at ancient landslides. There exist three main kinds of collapse patterns： bank scour collapse, creep-crack deformation ,sliding and tension-fracturing. The originating mechanism, developing process and the stability variation for each typical landslide at different water levers are analyzed. Stable slope angle after bank scour-collapse are analyzed statistically. Finally, conclusions are drawn that the geological structure and the layer lithology are the intrinsic factors of bank collapse,while dynamic water pressures caused by water lever decline are extrinsic factors.