Seismic Analysis for Nuclear Power Safety Related Bridge

Abstract

For the first time in China’s nuclear power industry, an in-plant emergency access bridge is proposed to be constructed. This bridge inside the nuclear power plants will serve as an important emergency evacuation route and as an access port for rescue operations in the power plant under potential accident conditions. Thus, the seismic safety of the bridge is a critical matter. This paper, which is based on a real engineering project, builds a refined finite element (FE) model for a continuous girder bridge-foundation structure. A seismic wave input method based on a nonlinear artificial boundary is used to suggest a reasonable size for a truncated foundation area for the purposes of dynamic simulations. The paper further discusses the influences of the nonlinear viscous artificial boundary and other various seismic wave input methods on the dynamic response of the bridge. Results show that compared to the traditional viscous artificial boundary, a nonlinear viscous artificial boundary has a better absorbing effect. The error of the bending moments at the bottom of piers improves from around 3.2% to around 1.9%. At the same time, compared to the “bottom wave + lateral free” and “bottom wave + lateral shear” of two seismic wave input methods, the nonlinear wave input method can generate results with higher accuracy. With the nonlinear input method, the error of the bending moment at the bottom of piers improves from around 13.7% to around 1.9%.