基于二维相干性自锚式悬索桥的地震响应研究

Study on Seismic Response of Self-anchored Suspension Bridge Based on 2D-coherence Model

摘要:

一般在非一致地震激励的模拟中采用一维相干模型,即模型中只含有沿地震波传播方向的变量,但垂直于地震波传播方向两点距离较远(如横桥向)时,会存在相干性。本文基于二维相干模型,应用三角级数法,考虑频率对视波速的影响、地震波传播滞后对非平稳调制函数的影响,生成某自锚式悬索桥桥址处各支点的人工地震波。利用该地震波研究不同激励方式对自锚式悬索桥结构的地震响应,并与基于一维相干的地震响应结果进行了对比,从中得到一些有意义的结论。

Abstract:

Usually the 1 D-coherence model is used to simulate seismic excitation, that means only a variation which travels along the direction of seismic wave is considered. However, when the distance between two points, which are at vertical direction to the wave way, is some long （ e. g. at both side of a bridge } , the coherence appears. In this paper, based on 2D-coherence model, using the triangular series method, considering the effect of frequency to wave velocity and the effect of seismic wave lag to non-uniformly modulation function, the artificial seismic wave is formed to every support of a self-anchored suspension bridge. The wave is used to research the seismic responses of the bridge structure in different excitation way. The result is compared with the result of 1 D-coherence, and from comparing some valued conclusions are gained.