Seismic performance analysis and optimization of the radial gate in Jishixia hydropower station

Abstract Aiming at the seismic safety of hydraulic metal structures in the high-intensity seismic region of Northwest China, this study considers the spillway radial service gate of the Jishixia Hydropower Station in the Yellow River Basin as the research object. A dynamic time-history analysis method was employed to numerically simulate the complex dynamic response under Intensity VIII seismic action. The results indicated the significant spatial distribution characteristics of the dynamic response. The peak displacement is concentrated in the central area of the top of the skin plate, and a significant stress concentration occurs in the mid-span areas of the main girder and radial arms, which are key components of the gate. A comparison with the static stress experimental results confirms that the peak dynamic response under a seismic load can reach 1.7 times the static experimental value. To enhance the seismic performance of the gate, structural optimization schemes involving local stiffening of the main girder and diagonal bracing of the radial arms were proposed without altering the existing structure. The simulation results show that, after optimization, the maximum displacement of the overall gate structure is reduced by 7.9%, and the amplitude of the dynamic stress at key parts of the gate is attenuated by more than 6.21%. This study provides a theoretical basis and technical support with significant engineering application value for safe design and performance improvement of gates in high-intensity seismic regions.