快速降水条件下土石坝稳定性及最安全类型分析

Stability Analysis of Earth-Rockfill Dams and Identification of the Safest Type in Terms of Rapid Water-level Drop

摘要:

文章通过对典型土石坝(包括均质坝、心墙坝(CCD)及倾斜上游心墙坝(SUCD))在快速水位下降期间的横截面进行饱和-非饱和渗流与应力的瞬态分析,采用有限元法(FEM)结合抗剪强度折减技术,评估上游边坡的安全系数。结果表明:在水位快速下降过程中,心墙坝的安全因子降低率显著低于均质坝和上游倾斜心墙坝,分别为其0.72~0.85倍和0.17~0.40倍,表明心墙坝在水位快速下降条件下具有更高的稳定性。

Abstract:

The paper conducts transient analyses of saturated-unsaturated seepage and stress on cross-sections of typical earth-rockfill dams, including homogeneous dams, central core dams (CCDs), and sloped upstream core dams (SUCDs), during rapid water-level drop. The finite element method (FEM) combined with the shear strength reduction technique is adopted to evaluate the safety factor of the upstream slope. The results show that during rapid water-level drop, the reduction rate of the safety factor for central core dams is significantly lower than that for homogeneous dams and sloped upstream core dams, being 0.72~0.85 times and 0.17~0.40 times of the latter two respectively, indicating that central core dams exhibit higher stability in terms of rapid-water drop.