心墙堆石坝水力劈裂可靠性分析方法及应用

首先利用水力劈裂判断准则，构造心墙水力劈裂功能函数；然后根据坝体材料物理参数的概率分布类型，采用几何法计算心墙水力劈裂可靠指标，得出心墙发生水力劈裂的概率。实例分析结果表明，蓄水初期，心墙上游面中部发生水力劈裂的概率较顶部和底部大；随着心墙材料的泊松比、密度变异性的增加，心墙发生劈裂破坏的概率也相应增加；弹性模量对心墙水力劈裂影响程度较小；降低蓄水速度可以降低心墙发生水力劈裂的概率。

RELIABILITY APPROACH TO ANALYZE HYDRAULIC FRACTURING IN EARTH CORE ROCK-FILL DAM AND ITS APPLICATION

At present, deterministic method is employed to analyze hydraulic fracturing. But characteristics of earth and rock show great variability forming in combination of geologic, environmental, and physical-chemical processes in far-flung geological age. Consequently the results obtained using deterministic method can not reliably indicate whether earth core can be fractured by water pressure or not. The effects of variability of dam materials to hydraulic fracture in the core can be considered using probabilistic methods to analyze hydraulic fracturing. According to probability distribution of physical parameters of dam materials, hydraulic fracturing criterion is used to construct the function of hydraulic fracturing in the core. Accordingly reliability index of hydraulic fracturing in the core is calculated through Geometry method, and probability of hydraulic fracturing in the core can be obtained. Taking one earth core rock-fill dam for example, the method mentioned above is used to analyze hydraulic fracturing in the core. The results suggest that the probability of hydraulic fracturing in the core increase with great variability of elastic modulus, Poisson’s ratio, density of dam materials, and effect of core material to hydraulic fracturing is different to shell material. In addition the effect of water filling rate on the potential of hydraulic fracturing in the core is also analyzed.