大跨度三塔悬索桥地震位移控制效果对比

Comparative study on the effectivness of seismic displacement control of long-span triple-tower suspension bridge

针对地震作用下超大跨度悬索桥梁端位移过大的问题,通过附加减震阻尼器保证桥梁结构的安全至关重要。考虑行波效应对大跨度悬索桥地震响应的影响,以主跨2×1 080 m的大跨度三塔悬索桥泰州大桥为研究对象,研究了弹性拉索、黏滞阻尼器、软钢阻尼器控制超大跨度悬索桥地震响应的最优参数取值,并对比了其地震响应控制效果。结果表明:弹性拉索和软钢阻尼器可较好的控制塔梁相对位移;黏滞阻尼器对塔梁相对位移的控制效果次于弹性拉索和软钢阻尼器,但黏滞阻尼器在控制塔梁相对位移的同时未显著增加塔底内力。

Seismic displacement at the end of the main girder of a bridge subjected to strong ground motion may exceed the allowed level.Thus,adding suitable seismic reduction devices between the tower and the main girder is necessary to control the relative displacement of both parts involved.Considering the effect of traveling wave velocity on the seismic response of a long-span suspension bridge,this study investigates the optimum parameters of elastic cables,viscoelastic dampers,and mild steel dampers to control the seismic response of Taizhou Bridge,a long-span triple-tower suspension bridge with main span of 2 m×1 080 m.Their seismic reduction performance was compared.Results show that the relative displacement between the main girder and the tower can be effectively controlled with an elastic cable and mild steel damper than with a viscoelastic damper,whereas the relative displacement can be controlled using a viscoelastic damper without greatly increasing the inner force at the bottom of the towers.