大跨度斜拉桥顺桥向阻尼约束体系研究

Study of Longitudinal Damping Restraint Systems for a Long Span Cable-Stayed Bridge

为探讨E型钢阻尼器和液体粘滞阻尼器对大跨度斜拉桥的减震限位效果,以某(55+135+400+135+55)m半飘浮体系双塔斜拉桥为背景,设计2种阻尼约束减震体系方案。采用通用有限元程序SAP2000建立桥梁动力分析模型,通过参数分析确定较为合理的减隔震设计参数,选取3条人工地震波分析2种阻尼约束减震体系方案对该桥地震响应的影响规律。分析结果表明:选取的E型钢阻尼器和液体粘滞阻尼器均可有效控制地震作用中斜拉桥主梁的水平位移,采用液体粘滞阻尼器时塔底弯矩增幅相对较小,主梁水平位移控制效果相对较好。综合考虑减震限位效果及综合使用性能,在该斜拉桥中推荐使用液体粘滞阻尼器约束减震体系方案。

To study the effect of seismic mitigation and displacement limiting of the E-shape steel dampers and fluid viscous dampers used for long span cable-stayed bridge, a semi-floating system cable-stayed bridge with double pylons and with span arrangement （55 ＋ 135 ＋400 ＋ 135＋ 55） m was cited as an example and two damping restraint system schemes for the seismic mitiga- tion and displacement limiting were designed. The dynamic analysis model for the bridge was es- tablished by the universal finite element program SAP2000, the rational seismic mitigation and i- solation design parameters were determined on the basis o{ the parametric analysis and three arti- ficial seismic waves were selected to analyze the laws of influence of the two damping restraint system schemes on the seismic responses of the bridge. The results of the analysis indicate that both the selected E-shape steel dampers and fluid viscous dampers can effectively control the hori- zontal displacement of the main girder of the cable-stayed bridge under the seismic action. When the fluid viscous dampers are used, the increase of bending moment in the pylon footings is rela- tively little and the effect of the horizontal displacement control of the main girder is relatively good. In consideration of the effect of the seismic mitigation and displacement limiting and the comprehensive service performance of the dampers, the fluid viscous damper scheme is finally rec- ommended for use in the cable stayed bridge.