Concrete socket is considered as a functional structure to improve the displacement and stress distribution, and enhance the stability of high arch dam and abutment, especially when geological condition of such large rock engineering is defective, but lack of particular clear mechanism description. The evaluation of concrete socket effect in this paper, resulting from numerical simulation for Baihetan arch dam is based on a particular nonlinear finite element method, in which Deformation Reinforcement Theory (DRT) is applied. The mechanism of action is clarified generally from two perspectives: the first one contains conventional parameters such as displacement, stress and volume of plastic zone; from the second one, Plastic Complementary Energy (PCE) of such as left bank, right bank and dam, is adopted to quantify the structure stability, and unbalance force is considered as measurement of local area failure, in a sense of characterizing the distance of local stress state beyond the yield surface during the overloading process. It is suggested that evaluation based on deformation reinforcement theory can also be a reliable reference of high arch dam design and construction.
Chinese history of high arch dam construction has lasted for more than 30 years, during which Ertan arch dam was completed and has been under normal operation so far, in addition, many other 300m level high arch dams such as Xiaowan, Xiluodu and Laxiwa are also under construction. Due to their unfavorable geological condition of the dam foundation and asymmetry of both sides of abutment, concrete socket is always designed to enhance dam body and adapt to adverse topographical and geological condition of foundation. In order to reduce the load on abutment rock mass and improve state of stress and strain of dam, the concrete socket located in riverbed or abutment is particularly assumed to be applicable, especially where geological condition of lower part of foundation is poorer than the upper part. It is clearly informed that concrete socket is set in international finished dam cases like Vaiont arch dam in Italy and Enguli arch dam in Georgia, and proposed dam case like Jingpin-1 high arch dam and Baihetan arch dam in China.