Error study of Westergaard's approximation in seismic analysis of high concrete-faced rockfill dams based on SBFEM

The error of dynamic stress in slabs of high concrete-faced rockfill dam (CFRD) caused by the Westergaard simplified hydrodynamic pressure method, which is broadly used at present, and the mechanism of the error generation are analysed. The accurate SBFEM hydrodynamic pressure method is also employed for providing comparison benchmark. In this study, a 3D FEM dynamic analysis of a 300 m CFRD is conducted under seismic loading in different directions. The results indicate that the Westergaard method produces large errors in the dynamic stress in face slabs along the slope direction. It is necessary to compute the hydrodynamic pressure by the accurate SBFEM in the CFRD-reservoir dynamic interaction analysis.