عنوان مقاله [English]
: In this research, effects of the presence and variations of dam lakes water level on block toppling failure of rock slopes facing the lakes have been investigated. First, a brief history of the researches carried out on toppling failures is presented. Then, a theoretical model is proposed, for different impounding states, for rock slopes facing dam lakes and having a potential of block toppling failure. Next, on the basis of the proposed model, a new approach is presented for the stability analysis of such rock slopes. Since this analysis is very time consuming we first, using the proposed relationships, prepared a special computer code (in MATLAB environment) that receives, from the user, the data of the slope and predicts its stability against block toppling failure for different impounding states of the dam lake. Finally, as a case study, the slope facing the headrace tunnels of Moshampa dam, in Zanjan province, Iran, was analyzed and assessed using the model and code proposed in this paper.