振动与冲击
振動與遲擊
진동여충격
JOURNAL OF VIBRATION AND SHOCK
2014年
5期
187-192
,共6页
桥梁%近场竖向地震%橡胶支座%多次碰撞%碰撞力
橋樑%近場豎嚮地震%橡膠支座%多次踫撞%踫撞力
교량%근장수향지진%상효지좌%다차팽당%팽당력
bridge%near-field vertical earthquake%rubber bearing%multiple poundings%pounding force
考虑桥梁橡胶支座的作用，建立了双跨连续梁桥的梁-弹簧-杆模型，采用瞬态波函数展开法和组合体瞬态内力法，提出了在先期到达的竖向地震激励作用下，桥梁结构竖向碰撞力的理论求解方法，计算结果表明本文方法可以合理地求解桥面与橡胶支座的多次竖向碰撞力。通过对不同竖向地震反应谱、不同桥梁跨度和不同竖向地震激励幅值下的碰撞次数和碰撞力的计算和分析表明，在浅源近场竖向地震作用下，桥梁可能出现竖向碰撞现象，桥面与橡胶支座的竖向碰撞力的幅值大，对桥梁具有相当大的危害。研究表明，竖向碰撞现象的出现很有可能存在两个条件，即竖向地震激励周期逼近于桥梁整体结构的固有振动周期，以及竖向地震激励幅值过到某个确定的阀值。另外，计算结果还表明，竖向碰撞力随竖向地震激励周期、幅值和桥跨长度的变化，呈现出复杂的非线性效应。
攷慮橋樑橡膠支座的作用，建立瞭雙跨連續樑橋的樑-彈簧-桿模型，採用瞬態波函數展開法和組閤體瞬態內力法，提齣瞭在先期到達的豎嚮地震激勵作用下，橋樑結構豎嚮踫撞力的理論求解方法，計算結果錶明本文方法可以閤理地求解橋麵與橡膠支座的多次豎嚮踫撞力。通過對不同豎嚮地震反應譜、不同橋樑跨度和不同豎嚮地震激勵幅值下的踫撞次數和踫撞力的計算和分析錶明，在淺源近場豎嚮地震作用下，橋樑可能齣現豎嚮踫撞現象，橋麵與橡膠支座的豎嚮踫撞力的幅值大，對橋樑具有相噹大的危害。研究錶明，豎嚮踫撞現象的齣現很有可能存在兩箇條件，即豎嚮地震激勵週期逼近于橋樑整體結構的固有振動週期，以及豎嚮地震激勵幅值過到某箇確定的閥值。另外，計算結果還錶明，豎嚮踫撞力隨豎嚮地震激勵週期、幅值和橋跨長度的變化，呈現齣複雜的非線性效應。
고필교량상효지좌적작용，건립료쌍과련속량교적량-탄황-간모형，채용순태파함수전개법화조합체순태내역법，제출료재선기도체적수향지진격려작용하，교량결구수향팽당력적이론구해방법，계산결과표명본문방법가이합리지구해교면여상효지좌적다차수향팽당력。통과대불동수향지진반응보、불동교량과도화불동수향지진격려폭치하적팽당차수화팽당력적계산화분석표명，재천원근장수향지진작용하，교량가능출현수향팽당현상，교면여상효지좌적수향팽당력적폭치대，대교량구유상당대적위해。연구표명，수향팽당현상적출현흔유가능존재량개조건，즉수향지진격려주기핍근우교량정체결구적고유진동주기，이급수향지진격려폭치과도모개학정적벌치。령외，계산결과환표명，수향팽당력수수향지진격려주기、폭치화교과장도적변화，정현출복잡적비선성효응。
A theoretical solving approach for multiple pounding forces acting on a bridge under near-field vertical earthquake was presented with the consideration of rubber bearings installed.The bridge was simplified as a continuous model of beam-spring-rod,and the problem was solved by making use of the expansion of transient wave functions in a series of eigenfunctions and the transient internal force method to determine the contact interfacial forces in a combined body.The numerical results showed that the presented approach can be used to solve reasonably the multiple pounding forces between the deck of the bridge and rubber bearings.The pounding forces and the pounding number under different vertical earthquake spectra,periods,and amplitudes as well as with different span lengths of the bridge were calculated. It was illustrated that the vertical pounding phenomenon can take place under near-field vertical earthquake,and damage the bridge before the horizontal earthquake reaches;there may exist two conditions leading to vertical poundings,the one is the vertical earthquake period close to the natural period of the bridge and the other is the amplitude of vertical earthquake exceeding some threshold;the vertical pounding force varies with the changes of vertical earthquake period, vertical earthquake amplitude and bridge span length.
