黏土心墙水力劈裂机理的离心模型试验及数值分析

采用与原型实际心墙边界条件、受力方式相同的土柱模型，进行了离心模型试验研究，同时采用数值计算分析的方法对土柱模型的应力变形特性进行研究以分析形成心墙水力劈裂的内在机理。分析结果表明：当心墙上游侧的库水压力大于心墙的土压力时，造成了心墙的水力劈裂破坏；该破坏是由于心墙在这种应力条件下，上游侧出现了有效应力拉应力区，并进而出现拉裂裂缝后所产生的；外部水压力大于心墙上游侧土压力是决定水力劈裂发生的重要因素。

Centrifugal model test and numerical analysis on mechanism of hydraulic fracturing of clay corewall in rockfill dam

The centrifugal model test on clay column with the boundary conditions and load mode are the same as those in prototype was carried out. At the same time the deformation of the model was analyzed by numerical simulation to investigate the mechanism of hydraulic fracturing of clay corewall. The model test and analysis result show that when the pressure of reservoir water acting on the upstream side of the clay corewall is higher than the earth pressure the hydraulic fracturing will happen. The fracturing is due to the occurrence of tensile stress under this stress state, and the cracking happens consequently. The quantitative relationship between water pressure and earth pressure is the critical factors determining whether the hydraulic fracturing will occur or not.