某水电站近坝库岸滑坡涌浪预测研究

Surge Prediction Study of Reservoir Bank Landslide near a Hydropower Dam

水电站建设及建成发电运行以后,伴随着水库蓄水,往往不同程度地触发岸坡岩土体失稳,不仅影响工程建设的实施,而且对拦河大坝和周围人民群众的生命财产安全造成严重威胁。本文以某水电站近坝库区的荒田滑坡为例,分析其滑动成因和机制;在启动速度和下滑速度计算的基础上,对其滑动入水后形成的涌浪进行分析和量化计算。根据山区河道型水库的特点提出弯道系数的概念并修正潘家铮计算公式,该系数主要由大坝附近涌浪监测结果反分析获得。基于数值计算确定不同水位情况下的失稳范围,采用上述修正方法对库区一处潜在失稳区岩土体进行滑动入水后的涌浪预测,从而获得较为可靠的预测结果,为水电站的安全运行提供重要依据。

The reservoir storage, in the process of hydropower station construction or operation, often triggers a large number of reservoir bank slope instability of rock and soil mass in different degrees, which not only affect the implementation of the project construction, but also seriously threaten the river dam and surrounding people’s safety. The Huangtian landslide in a hydropower station reservoir area close to the dam was taken as an example, the sliding causes and mechanism of which were analyzed in this paper;on the basis of start-up speed and slip velocity calculation, the surge after sliding into the water was analyzed and quantified. The concept of curve coefficient that obtained from the surge monitoring results nearby the dam by inverse analysis was proposed according to the characteristics of mountainous river reservoir and used to amend the Pan Jiazheng formulas about the surge. Based on the instability scope which was determined by numerical calculation under different water conditions, the surge was forecasted by the above method when the rock and soil in a potentially unstable reservoir area can slide into the water, so as to obtain more reliable predictions and provide an important basis for the safe operation of hydropower station.