Seismic response analysis of Dagangshan arch dam during 2022 Luding Ms 6.8 earthquake using source-to-structure simulation

The source-to-structure simulation, bridging the gap between regional wavefield simulation and seismic response analysis of local structures, holds promise for predicting the seismic response of arch dams in potential earthquakes. However, accurately forecasting fault rupture processes for potential earthquakes and obtaining highresolution velocity structures for most regions remain significant challenges. This paper is to investigate the viability of the source-to-structure simulation framework for predicting seismic responses of dams in regions with the limited accessible data. For this purpose, the seismic response of Dagangshan arch dam during the 2022 Luding Ms 6.8 earthquake is analyzed as a case study. The multidimension source model is constructed using an accessible preliminary source inversion results within a limited frequency band, and the velocity structures are obtained by modifying the available tomography model. The results demonstrate a strong consistency between the simulated seismic response and the observations, indicating that the source-to-dam simulation is robust. Furthermore, two earthquake input mechanisms, the internal input method and the free field input model, are compared for weak coupling strategy within the source-to-dam simulation framework. It is proven that the free field input method exhibits comparable feasibility to the internal input method and saves the computation requirements for implementing the source-to-dam simulation.