Dynamic response analysis of high earth-rockfill dam subjected to P wave with arbitrary incoming angles

Abstract

The dynamic response analysis of high earth-rockfill dams mostly only considers the vertical incidence of seismic waves. However, due to the randomness and uncertainty of earthquakes, for near-field earthquakes, oblique incident waves generally dominate. Therefore, understanding the nonlinear dynamic response of high earth-rockfill dams under the oblique incident seismic wave is of great significance to the seismic safety evaluation of the dams. For this purpose, the seismic wave input method of P wave with arbitrary angle that considers near-field oblique incidence is proposed, which is realized through the Fortran program, and the validity and accuracy of the method and the program are verified by two examples. The proposed method is applied to study the dynamic response analysis of the Nuozhadu earth core rockfill dam under oblique incident P wave. In addition, the three-dimensional interaction system of the dam-foundation-canyon is considered based on the viscous-spring boundary model, which reflects as much as possible the environmental conditions of the high earth-rockfill dam when the actual earthquake occurs. The numerical results reveal that the incident angle of P wave significantly affects the dynamic response of the dam. For acceleration amplification factor and residual deformation, the most damaging incident angle is the incident angle α = 60°, rather than in the vertical direction. Besides, when the seismic wave is incident obliquely, the value of residual deformation along the transverse direction is greater than that along the stream direction. It is recommended that the influence of oblique incident P wave should be considered in the seismic design of high earth-rockfill dams.