大型高拱坝嵌深对坝肩块体稳定性的影响分析

Analysis of the influence of embedded depth of large high arch dams on the stability of dam abutment blocks

结合古学拱坝坝肩不同嵌深设计方案,利用刚体和有限元极限平衡法,对坝肩块体进行稳定性分析,研究了高拱坝嵌深变化对坝肩块体稳定性的影响规律。结果表明,拱坝嵌深的增加会产生块体体积、滑面面积减小和拱推力增加两种效应,分别增加和降低块体稳定性,因此坝肩块体抗滑稳定安全系数随嵌深增加呈现出持续增大、持续减小、先增后减、先减后增4类变化趋势。经比选,推荐古学拱坝采用左岸嵌深36.5m、右岸嵌深40.5m的中嵌深方案。

Combining different embedded depth design schemes of Guxue arch dam abutment,stability analysis was conducted on the abutment block using rigid body and finite element limit equilibrium methods,and the influence of changes in embedded depth of high arch dams on the stability of the abutment block was studied.The results show that the increase of the embedded depth of the arch dam will produce two effects,namely,the reduction of the block volume,the sliding surface area and the increase of the arch thrust,which will increase and decrease the stability of the block,respectively.Therefore,the anti sliding stability Factor of safety of the dam abutment block shows four trends of continuous increase,continuous decrease,first increase then decrease,first decrease then increase with the increase of the embedded depth.After technical and economic comparison,it is recommended that the Guxue arch dam adopt a medium embedding depth scheme with a left bank embedding depth of 36.5m and a right bank embedding depth of 40.5 m.