古田溪三级大坝沿软弱夹层抗滑稳定分析

Sliding stability analysis of Gutianxi third cascade dam along soft interlayer

根据非线性有限元法应力计算结果 ,通过自动搜索确定最小安全系数研究古田溪三级大坝沿软弱夹层抗滑稳定性 .考虑整体坝段两侧软弱夹层以上岩体的阻滑作用 ,整体两侧岩体分配给中间坝段的阻滑力采用简化计算 .根据中间坝段的计算结果 ,评价整体坝段沿软弱夹层的抗滑稳定性 .计算结果表明 ,沿软弱夹层的整体抗滑稳定不能满足设计要求 .另外 ,提供了扬压力等效结点荷载的体积分有限元计算公式 ,探讨了坝后冲刷坑对抗滑稳定的影响 .

Sliding stability of the Gutianxi third cascade dam along soft interlayer is studied with the minimum safety factor that is determined through automatic search, based on stress results calculated with nonlinear FEM. Both side resistance to sliding of the rock body above soft interlayer is considered within the range of integrated monoliths and it distributed to a middle monolith by using a simplified numerical method. The sliding stability of the integrated monoliths is evaluated with the calculated results of middle monoliths. The computed results show that the integrated sliding stability along soft interlayer does not meet with design requirements. Meanwhile, the FE formula of volume integration is provided to calculate equivalent nodal loads of uplift and the effect of the scour pole behind dam on sliding stability studied.