Seismic Resilience-Based Design Method for Hybrid Bridge Pier Under Four-Level Seismic Fortifications

摘要

Abstract The hybrid bridge pier can be damaged in stages under earthquakes, and have great repairability after earthquakes, but the existing seismic fortification objectives cannot reflect the superiority of the hybrid bridge pier. Therefore, higher seismic fortification objectives and the corresponding seismic design method are needed for the hybrid bridge pier. A design example of the hybrid bridge pier was presented. Combined with the seismic ground motion parameter zonation map of China, the four-level seismic fortification objective of the hybrid bridge pier based on seismic resilience is proposed. By formulating the material and structural parameters of the hybrid bridge pier, the seismic force of the pier under the four-level earthquake resistance is calculated. It is shown that with the deepening of the damage degree of the pier, the decrease of the structural stiffness leads to the increase of the natural period of vibration of the structure, which leads to the decrease of the seismic force acting on the structure, and thus the concept of the follow-up stiffness is proposed.