Seismic deformation and seismic resistance analysis of Shapai Roller Compacted Concrete Arch Dam based on field monitoring and dynamic finite element method

Shapai Roller Compacted Concrete (RCC) Arch Dam is the highest RCC arch dam of the 20th century in the world with a maximum height of 132 m, and it is the only concrete arch dam near the epicentre of Wenchuan earthquake on May 12th, 2008. The seismic damage to the dam and the resistance of the dam has drawn great attention. This paper analyzed the response and resistance of the dam to the seismic wave using numerical simulations with comparison to the monitored data. The field investigation after the earthquake and analysis of insitu data record showed that there was only little variation in the opening size at the dam and foundation interface, transverse joints and inducing joints before and after the earthquake. The overall stability of the dam abutment resistance body was quite good except a little relaxation was observed. The results of the dynamic finite element method (FEM) showed that the sizes of the openings obtained from the numerical modeling are comparable with the monitored values, and the change of the opening size is in millimeter range. This study revealed that Shapai arch dam exhibited high seismic resistance and overload capacity in the Wenchuan earthquake event. The comparison of the monitored and simulated results showed that the numerical method applied in this paper well simulated the seismic response of the dam. The method could be useful in the future application on the safety evaluation of RCC dams.