基于随机场理论的水电工程渣料场边坡稳定性分析

Stability Analysis of Abandoned Dreg Sites of Hydropower Projects Based on the Random Field Theory

渣料抗剪强度参数的空间变异性对渣料场边坡稳定性的影响非常显著。利用随机场理论开展抗剪强度参数空间变异性对水电工程渣料场边坡稳定性影响的分析,首先采用自相关函数构建抗剪强度参数随机场,然后利用改进的乔列斯基分解法离散抗剪强度参数随机场,最后利用非侵入式随机有限元方法进行边坡稳定性分析。算例结果表明岩土体抗剪强度参数的空间变异性对边坡安全稳定性有较大影响,边坡滑动面与抗剪强度参数的空间分布有关。工程实例计算结果表明,对于水电工程渣料场这一典型的非均质边坡,单一的安全系数不足以评价渣料场边坡的稳定性,应考虑渣体抗剪强度参数的空间变异性,并结合工程实际进行稳定性及滑动面的综合分析和评价。

The spatial heterogeneity of shear strength is crucial to slope stability analysis. To analyze the influence of spatial variability of shear strength on the stability of abandoned dreg site slopes, the random field theory is used. The random field of shear strength parameters is generated through the autocorrelation function and discretized by improved Cholesky decomposition technique. The non-intrusive stochastic FEM is used to analyze the stability of abandoned dreg site slopes. The results of the present example indicate that with the consideration of the spatial variability of shear strength parameters, the obtained sliding surface of the slope is related to the distribution of parameters. Different parameter distributions can give different sliding surfaces as well. The results of a practical project indicate that spatial heterogeneity of shear strength parameters significantly influences the slope stability. Hence, a single safety factor cannot completely determine the stability of abandoned dreg sites. The spatial variability of shear strength parameters should be considered in the slope stability analysis.