楞古水电站雨日堆积体岸坡稳定性研究

Study on Slope Stability of Yuri Accumulation Body in Lenggu Hydropower Station

雨日堆积体位于雅砻江中游楞古水电站上、下比选坝段之间,总体积约2 100万m3,其下部基岩边坡浅表部发育松动变形岩体,体积约420万m3,直接关系到坝段的选择。根据现场地表地质调查及勘探揭示成果,建立了详细的地质模型,采用极限平衡法、拉格朗日差分法计算其稳定性。结果表明,雨日堆积体及下部松动变形岩体在各种工况下整体稳定性均较好,在地震、下坝段蓄水工况下有发生局部变形失稳的可能,对上、下坝段方案影响均较小。

Abstract： Yuri Accumulation Body is located between two proposed dam sites of Lenggu Hydropower Station in the middle reaches of Yalong River. The total volume of Yuri Accumulation Body is about 21 million m3, and the shallow surface of its lower slope develops a slackened rock mass with a volume about 4.2 million m3. The stability of this accumulation body has a direct impact on dam site selection. According to the results of geological survey and exploration, the geological model of this accumulation body is established to analyze its stability by Limit Equilibrium Method and Lagrangian Difference Method. The results show that the accumulation body and its lower slackened rock mass are good in overall stability under all conditions, but may be unstable in local when earth-quaking or reservoir filling. This accumulation body has little effect on two dam site program.