大跨度桥梁结构多级地震响应研究
Study on the Multistage Seismic Response of Long-span Bridge Structures

大跨度桥梁结构在地震发生时其支承点受到的地震动激励均不相同，使得在多级地震中其桥梁结构对于地震的响应程度也不同。通过分析多级地震作用下，水中结构的运动引起桥梁墩部周围水体辐射波浪运动对桥梁结构的影响，分析大跨度桥梁墩-水耦合边界。基于反应谱理论，计算大跨度桥梁结构承受的地震力最大值，得出多级地震响应曲线，以分析其多级地震响应；并以某地六跨桥为例，以多级地震下桥梁的位移、剪力、弯矩等响应时程为指标进行分析，得出有效结论。
As a public facility, the seismic performance of long-span bridges has been frequently studied. The seismic excitations that are inputted on the supports of long-span bridge structures are different under earthquakes; consequently, the responses of bridge structures under multistage earthquakes are different. This research analyzes the influence of the radiation wave motion around a bridge pier on the bridge structure under the action of a multilevel earthquake and discusses the pier-water coupling boundary of long-span bridges. Based on the response spectrum theory, the maximum seismic force endured by the long-span bridge structure is calculated, and the multilevel seismic response curve of the structure is obtained. Furthermore, taking a six-span bridge as an example, this research analyzes the response time histories of displacement, sheer force, and bending moment of the bridge under multistage earthquakes and presents some effective conclusions.