高烈度区大跨径斜拉桥纵桥向抗震体系研究

Study of Longitudinal Aseismic System of Large-span Cable-stayed Bridge in High Seismic Intensity Region

高烈度区的斜拉桥地震响应较大,要求主塔等重要结构保持在弹性范围内并要有效控制主梁位移,因此选择合理的纵桥向抗震体系就显得尤为重要。通过归纳并比较了现有的各种纵向抗震体系的设计理念,分析了各种纵向抗震体系的纵桥向传力机理,基于一座斜拉桥实例,比较了3种抗震体系的结构地震反应。详细的参数分析表明,采用纵桥向弹性约束体系,选取合理结构参数,可大幅减小主塔的地震内力和主梁地震位移。

In high seismic intensity region, cable-stayed bridge will bear huge seismic force during earthquake.However, bridge tower, pile and other important components are required to be elastic, and seismic displacements are also required to be limited, so using a reasonable longitudinal aseismic system becomes very important.On the base of a real cable-stayed bridge, the seismic response of three different longitudinal aseismic systems are analysis and compared.Detailed parameter analysis results shows that when elastic longitudinal aseismic system is adapted and reasonable parameters are used, tower seismic force and girder seismic displacement will be reduced greatly.