曲线斜拉桥横向减震体系行为分析

Study on Seismic Behavior of Lateral Isolation System for Curved Cable-stayed Bridges

为研究斜拉桥横向减震体系的减震行为,以一座高低塔曲线斜拉桥为工程背景,结合桥梁新型横向钢阻尼器,给出了可行的斜拉桥全桥横向减震体系的优化设计方法,并与横向固定体系进行比较,分析了其减震效果。研究表明:地震作用下,斜拉桥横向减震体系能显著减小桥墩及其基础的地震需求,亦能一定程度上减小桥塔及其基础的地震需求,同时,将主梁的地震位移控制在合理范围内;钢阻尼器的滞回耗能能力明显优于摩擦型支座。

To investigate the seismic behavior of the lateral isolation system of curved cable-stayed bridge,a curve cable-stayed bridge with twin RC towers in different height taken as the prototype in this paper.Using a novel Transverse Steel Damper (TSD),a feasible design method for the lateral isolation system of cable-stayed bridges is proposed.Moreover,compared with the conventional transverse fixed system,the mitigation efficiency of the isolation system is analyzed.The results show that the lateral isolation system for cable-stayed bridges can significantly reduce the seismic force demands at piers and foundations,as well as at towers and its foundations.At the same time,the transversally relative displacements between deck and towers can be limited to a reasonable level.The energy dissipation capacity of TSDs are more excellent than that of the friction bearings.