First Author: YAN Chunli
Corresponding Author: TU Jin
Journal: Soil Dynamics and Earthquake Engineering

Abstract

This study, for the first time, establishes a high arch dam-foundation coupled finite element analysis model with tens of millions of degrees of freedom, comprehensively accounting for dam body damage, sliding instability, and their coupling effects. Nonlinear dynamic response analyses under different seismic overload factors were carried out, and performance indicators based on maximum damage depth ratio and sliding surface ratio were proposed. These indicators reveal the seismic failure mechanisms of high arch dam-foundation coupled systems.

To further evaluate the seismic safety of high arch dams, this study introduced relative displacement between the dam crest and the dam base as a performance indicator, and proposed an ultimate seismic capacity evaluation criterion based on cumulative damage at different overload factors. Results show that dam body strength failure and sliding instability evolve dynamically with seismic motion intensity. When seismic intensity is low, energy dissipation is dominated by a single failure mode; with increasing seismic intensity, both failure modes jointly contribute to energy release. Moreover, the ultimate seismic capacity of large arch dams corresponds to an overload factor of about 2.0.

Keywords: High arch dam; Multi-nonlinear coupling model; Damage failure; Instability failure; Failure mechanism; Evaluation indicators