Nonlinear dynamic response and damage analysis of hydraulic arched tunnels subjected to P waves with arbitrary incoming angles

摘要

Due to the randomness and uncertainty of the earthquake, the incoming angle of the seismic waves acting on the underground structure is also subject to great uncertainty. Most dynamic response analyses and seismic design for hydraulic tunnels are based on the assumption of vertically incoming seismic waves. This assumption may underestimate the nonlinear response of the hydraulic tunnels. Hence, understanding the nonlinear dynamic response and evaluate the damage of the hydraulic tunnels under obliquely incoming compression waves (P waves) is essential for better analysis and seismic design of hydraulic tunnels. For this purpose, the input method of P waves with arbitrary angle is presented and validated through two examples. In addition, the fluid-structure-rock interaction (FSRI) system is considered based on coupled Eulerian-Lagrangian method, to approximate the environment conditions of the hydraulic arched tunnels when the real earthquake occurs. The numerical results reveals that the incoming angle of P waves have great impact on the displacement peak index and the damage degree of hydraulic arched tunnel. It is recommended that the influence of obliquely incoming P waves should be considered in the seismic design of hydraulic tunnels.