超大跨悬索桥地震响应的综合最优控制研究

超大跨缆索支承桥梁通常选择隔震体系以减小桥塔的地震内力,但隔震体系会使得结构在强震下的梁端位移很大,必须采取控制措施以保证整体结构的抗震安全性。本文以主跨1 490 m的润扬悬索桥为研究对象,在对其地震响应特性进行分析的基础上,从振动控制的原理出发,探讨了控制超大跨悬索桥地震响应的具体的措施及参数选择,结合改进的层次分析法提出了地震响应综合最优控制的概念,构造了综合最优控制效果评估模型,并给出了该桥在给定地震输入下的综合最优控制措施。结果表明,对于超大跨悬索桥,在塔、梁间设置弹性连接装置或阻尼器都能减小梁端位移响应,但综合考虑其它部位的响应,阻尼器的减震效果更为全面。

Compositive Optimal Control of the Seismic Response for Super-Long-Span Suspension Bridges

In order to reduce the seismic force of the towers,the seismic isolation system is commonly adopted in super-long-span suspension bridges.But in this system,the seismic displacement at the end of the main girder may exceed the allowance,so suitable devices should be employed between the towers and the main girder to control the displacement.Based on the mechanism of vibration control,this paper investigated the selection of practical connection devices and the determination of their parameters,and the concept of compositive optimal control was proposed combined with modified AHP method.The Runyang Suspension Bridge with a main span of 1 490 m was taken as an example.After 3-dimensional nonlinear seismic analyses using different parameters of connection devices were carried out,the compositive optimal parameters of the connection devices were achieved.Results showed that both the elastic connection devices and the dampers with rational parameters could significantly reduce the seismic displacement of the bridge,but the dampers were better if all factors were considered.