大跨度拱桥抗震设计探讨

Discussion on Seismic Design of Long-span Arch Bridge

目前,国内外现有的绝大多数桥梁工程抗震设计规范只适应于中等跨度的普通桥梁,超过适用范围的大跨度桥梁的抗震设计,则无规范可循。结合生产实例对大跨度拱桥的抗震研究分析提出了设计主要进行强度验算,重视高阶振型的影响和多点不同步激振(包括行波效应)和竖向地震动的影响,必要时采取适当的减隔震措施以减小地震反应,同时注重抗震措施的采用,确保大桥在设计地震作用下满足设防标准要求。同时对抗震分析计算中遇到的问题加以分析进而提出相应的对策措施。

At present, the most existing bridge engineering seismic design codes at home and abroad are only suitable for the medium span of ordinary bridges. The seismic design of long-span bridge exceeding the application scope has no code to follow. Combined with the practical cases, the article puts forward that the design is mainly to check and calculate the strength, and pay attention to the influence of high order vibration mode, and the influence of multipoint desynchrony excitation(including traveling wave effect) and vertical seismic oscillation in the seismic study and analysis of long-span arch bridge. The suitable seismic mitigation and absorption measures are taken to decrease the seismic response if necessary. At the same time, the attention is paid to the application of seismic measures. The bridge is ensured to satisfy the preventive standard requirements under the design seismic action. The article analyzes the problems met in the seismic analysis and calculation, and puts forward the relative countermeasures.