Seismic Response of a Rockfill Dam with an Asphalt–Concrete Core under P Waves with Arbitrary Incident Angles

Abstract

The incident angles of seismic waves have a significant influence on the seismic response of asphalt–concrete core rockfill dams. This paper constructs the free field of elastic semispace under P waves with arbitrary incident angles and clarifies the variation law of the seismic intensity on the ground surface with incident angles γ and α. The free field on the foundation boundary under arbitrary combinations of angles γ and α are derived according to the wave-field superposition principle. Combined with the viscoelastic artificial boundary, the free field is transformed into the equivalent load on the boundary node, and the input method of the P wave with arbitrary incident angles is established. Finally, the seismic response of the asphalt–concrete core dam under P waves with arbitrary incident angles is studied. The results show that when the incident direction is perpendicular to the dam axis, the dynamic shear stress is the highest, and the local seismic safety factor of the dam is the largest. When the incident direction is parallel to the dam axis, the tensile stress of the asphalt core is the highest, there is a possibility of cracking at the contact part of the lower part of the asphalt core with the canyon, and the seismic subsidence rate of the dam crest is the highest. For the tensile stress of the asphalt core and the dam-crest subsidence rate, the most unfavorable incident angle α is 75° when the incident angle γ is the same.