黄河上游某滑坡坝渗透稳定性评价

为了对黄河上游某滑坡坝的渗透稳定性进行较深入研究，作者首先通过试验资料确定了坝体与湖底纹泥渗透稳定的可能破坏形式、临界水力坡降和允许水力坡降，在此基础上应用数值模拟方法(Modflow程序)对滑坡坝在正常湖水位与极限湖水位两种工况进行了渗透稳定性评价。具体评价方法为，在每种工况下先评价计算范围内最大水力坡降方向每一格点(计算剖分网格)的渗透稳定性，进而评价整个坝体的渗透稳定性。研究结果表明，在正常湖水位与极限湖水位两种工况下，坝体均不会出现渗透稳定性问题，在极限湖水位下，坝体的渗漏量变化不大(由2775m^3／d增加为3138m^3／d)。说明在漫长的历史过程中，堰塞湖已形成了很好的防渗铺盖，当水位高于溢洪道时，湖水主要通过溢洪道向外排泄。研究结果为下游某大型水电站的设计、施工与安全运营提供了理论依据。

Seepage stability assessment of a landslide dam located in the upper-reach of Yellow Rievr

In order to study the seepage stability of a landslide dam located in the upper-reach of Yellow River in detail,in this paper,based on all experimental materials,the authors determined possible damage forms,critical hydraulic slope,allowable hydraulic slope of landside dam and lacustrine varved clay,then adopted numerical method(MODFLOW program) to assess the seepage stability of landslide dam in two working conditions of mean lake stage and limiting lake stage.Assessing method is that,first,assessing seepage stability of every grid in direction of maximal hydraulic slope in mean flow season and limiting lake stage,and then assessing seepage stability of the whole landslide dam.The results proved that the landslide dam would not occur seepage stability problems in mean lake stage and limiting lake stage.In limiting lake stage,volume change of dam leakage is little(from 2775m~3/d to 3138m~3/d),shown in history,barrier lake had formed appropriate imperrious blanket,and when lake stage is higher than limiting lake stage,water would be drainaged by spillway.The results of this paper present theoretical basis for designing,construction and running of a downriver large-scale hydropower station.