Study on Failure Mechanism of Roller Compacted Concrete Gravity Dams by an Isotropic Damage Model

摘要

The roller compacted concrete gravity dam is poured by thin layers and there are many horizontal layer surfaces and joint surfaces in the dam. The shear strength of these surfaces is obviously lower than that of the RCC concrete. These horizontal layer surfaces and joint surface are the key positions affecting the strength, stability and seepage of the dam. The height of the most RCC gravity dams is about 100m. The height is relatively low and the horizontal thrust is relatively small. So anti-sliding stability issue along the layer surfaces has not attracted enough attention. But for the dams 200m high, this problem is very prominent. In this study, using an isotropic damage model, based on the effective stress principle of porous media, taking the stress-seepage-damage coupling effect into account, the failure mechanism of Huangdeng RCC gravity dam is discussed. The results show that the failure mechanism of RCC gravity dam is the shear slipping along the layer surfaces and the foundation surface.