Failure and overall stability analysis on high arch dam based on DFPA code

摘要

A code of practice for three dimensional cracking and a failure process analysis of high arch dams, based on the finite element method, dam failure process analysis (DFPA) has been developed. In this code, by changing mesh density, consideration of heterogeneity when calculating the elements is achieved. Random strength and elastic modulus are assigned to the elements in accordance with a Weibull distribution. A stress analysis is carried out based on consideration of the deformation of an elastic material containing an initial random distribution of microcracks, which simulates the progressive failure of solids. The dam cracking and failure process associated seismicity accumulation can be analyzed using acoustic emissions. The proposed method was applied in investigating the failure mechanism, and overall stability of the Xiluodu high arch dam. The numerical mesh model was fine, and the total number of hexahedral elements was 300 million. The DFPA analysis results, when compared with those derived by the Tfine code, and the 3D geomechanical model test show that the DFPA code is effective in fully simulating the failure processes of the dam and foundation. The analysis results were used to successfully guide the design of the Xiluodu high arch dam. The proposed DFPA method may also be of value to the reinforcement design and construction of high arch dams, associated with similar hydropower projects worldwide which are also located in complicated rock foundation areas.