基于電渦流阻尼器的超寬單肋拱橋減震研究

中圖分類號：U448.22 文獻標(biāo)志碼：A

Abstract：Inorder to study the application effect of eddy current damper in the field of seismic reduction of super-wide single-rib tiedarch bridge，thelongitudinal and transverse eddy current dampers are setat the active bearing position of the girder of a new composite structure system of a flexible single rib tiedarch bridg with backstays onan ultra-widebridge deck，respectively.The nonlinear time history analysis method isused to calculate the motion response of the structure under earthquake.In order to facilitate the calculation and application of the eddycurrent damper，the dampingforcemodel wassimplified，and the validityof the simplified model wasverified byexperiments.Finally，therelativedisplacementbetween the pierand girder，and the internalforceofthearch feet are taken as the evaluation indexes to studythe influence of viriable eddy curent damper parameters on the seismic response of the structure.The results show that the out-of-plane stiffnessof the structure system is low，and it is prone to lateral overturning under earthquake.The structure has high requirements on the bearing capacity of he arch foot.The double broken line model can beapproximately equivalent to the nonlinear damping force model of eddy current dampers，which is used to describe the mechanical properties of the eddy current damper .The installationof eddy current dampers can efectivelyreduce the dynamic response of the bridge structure under earthquake.When the maximum damping force of the damper is determined，the seismic motion response of the structure shows a significant downward trend with the increaseof the equivalent damping coeficient.The speed of decline is fast first and then slow，and finally tends toa level after thedampingcoeffcient reaches a certain threshold.The maximum damping force parameter determines theupper limit of the damping force of the eddy current damper.When the equivalent damping coeficient is constant，the motion response of each node of the structure continues to decrease with the increase of the maximum damping force within a certain range.

Key words：the arch-cable-girder collaborative system; single cable plane tiedarch bridge;ultra-wide bridge deck ;earthquake ;eddy current damping

單肋系桿拱橋具有行車方便、視野開闊、造型優(yōu)美以及經(jīng)濟性好等優(yōu)勢，常被應(yīng)用于市政橋梁等對景觀需求較高的場合.而隨著交通量需求的不斷增加，橋梁結(jié)構(gòu)的設(shè)計通行能力也要不斷提高，對于重要交通樞紐，路面寬度通常能達到 20m 以上，而對于這種寬幅橋面而言，面外穩(wěn)定性是制約系桿拱橋設(shè)計的重要因素[1-2]，尤其是在橋面超寬時，為規(guī)避復(fù)雜的面外失穩(wěn)問題，在采用系桿拱橋形式時往往會設(shè)計成雙拱肋甚至是多拱肋形式.但隨著研究對柔性吊桿非保向力認識的不斷提高[3-5]，發(fā)現(xiàn)以往單肋系桿拱橋的橫向穩(wěn)定性被嚴重低估，該種橋型完全有可能被應(yīng)用于超寬橋面結(jié)構(gòu)，如我國已建成的浙江衢江大橋[和福建福州灣邊大橋[]，均為單肋系桿拱橋，其橋面寬度分別達到了 30m 和 34m 業(yè)

在系桿拱橋的抗震分析領(lǐng)域，吳再新等[8]分析了大跨度剛構(gòu)拱橋在地震作用下的動力響應(yīng)，發(fā)現(xiàn)結(jié)構(gòu)墩梁結(jié)合區(qū)和主墩墩底是抗震薄弱環(huán)節(jié)；趙燦暉等[9]分析了連續(xù)剛架拱橋在地震作用下的內(nèi)力分布，發(fā)現(xiàn)拱腳處的地震內(nèi)力最大，抗震分析時應(yīng)以拱腳截面作為控制截面；劉應(yīng)龍等[在連續(xù)鋼桁梁柔性拱橋上設(shè)置黏滯阻尼器，研究發(fā)現(xiàn)阻尼器可以顯著提高拱橋的抗震性能；牛建濤等發(fā)現(xiàn)針對墩-梁固結(jié)體系地震響應(yīng)過大的問題，采用油阻尼器可以取得較好的橫向減震效果；孫建鵬等[12]發(fā)現(xiàn)摩擦擺支座 + 黏滯阻尼器……