Application of methods for life-cycle deformation control of high concrete-faced rockfill dams

The deformation of high concrete-faced rockfill dam (CFRD) has a particularly important influence on the safe opercation of impermeable face. To deal with the crushing damage of the impermeable face and the large leakage of dam body, which occurr in many constructed high CFRDs at home and abroad, the reservoirs have to lower the water level for maintenance, which has resulted in large economic losses and even safety hazards for long-term dam operation. Through analyzing the example of a high CFRD with crushing damage, it is found that the lack of systematic deformation control is the main factor for the crushing damage of the face. To prevent the damage of the impermeable face, a systematic method is proposed: "controlling the total deformation of the dam body, transforming harmful deformation, and adapting to vertical deformation". The method has achieved good results in Dongqing CFRD project, which uses mixed hard and soft rocks as dam materials. The project has been operating for more than ten years, and no signs of crushing damage have been detected in the impermeable face. The proposed method provides important reference experience for the design and construction of CFRDs of more than 200 m or even 300 m in height.