Simulation of near-fault ground motions in complex sites based on CPU-GPU heterogeneous parallelism by spectral element method

Base on CUDA programming platform, the workstation-level CPU-GPU heterogeneous parallel method is implemented, and the spectral element method is used to simulate ground motion near-fault in a real site. In this paper, the computational accuracy and efficiency of the proposed workstation-level CPU-GPU heterogeneous parallelism method are tested by simulating the spontaneous rupture model TPV15 provided by SECE/USGS. Furthermore, the proposed method is applied to the simulation of strong ground motion in 1679 M8.0 Sanhe-Pinggu earthquake, and therefore the applicability of the proposed method to the simulation of real ground motion is verified. The simulation results show that the computing time of CPU-GPU heterogeneous parallelism is significantly reduced than that of CPU parallelism, and the highest acceleration ratio is 3.04 and 2.16 times as long as CPU 36 core and 72 core respectively. The simulation results of M8.0 in Sanhe-Pinggu earthquake in 1679 clearly show the characteristics of near-fault ground motion, such as near-fault ground motion concentration, fault rupture directivity effect, velocity pulse and permanent displacement, and the influence of real terrain on near-fault ground motion. The results show that the CPU-GPU heterogeneous parallelism method can effectively improve the computational efficiency of spectral element method simulation, and it has a good prospect to be applied to seismic wave field simulation of large-scale complex sites.