四渡河大跨悬索桥空间地震响应分析
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摘要
非一致激励输入对大跨结构响应有着较大影响。本文以四渡河悬索桥为背景,首先根据该桥动力特性对规范反应谱进行调整,基于修正反应谱并考虑相位非平稳性合成地震动位移;然后编制了调索程序来确定有限元模型的初始平衡构型;采用时程法,分别分析了在纵桥向、横桥向以及竖向的非一致激励(行波输入、多点输入)下的悬索桥地震响应。计算结果表明,纵向非一致激励输入增大了悬索桥的地震响应,横向、竖向非一致激励输入的影响有增有减。
Nonuniform seismic ground motion has a great effect on the responses of long-span structure.Firstly,based on the phase difference spectrum having the characteristic of lognormal distribution,the artificial seismic ground motions simulating the code response spectrum are synthesized for a long-span suspension bridge across the Sidu River as an engineering background.Secondly,a program for the final geometry of the bridge due to dead loading is developed by manipulating the initial tension of the main cable. Then the time-history dynamic analysis method is used to compute the seismic responses of the bridge under longitudinal,lateral and vertical excitations,respectively.Finally a comparison between the responses of the bridge subjected to uniform and nonuniform seismic ground motions is drawn.The result indicates that the longitudinal nonuniform excitation may increase the response of the bridge,and that the lateral or the vertical excitation may increase or decrease the responses of the different parts of the suspension bridge.
Nonuniform seismic ground motion has a great effect on the responses of long-span structure.Firstly,based on the phase difference spectrum having the characteristic of lognormal distribution,the artificial seismic ground motions simulating the code response spectrum are synthesized for a long-span suspension bridge across the Sidu River as an engineering background.Secondly,a program for the final geometry of the bridge due to dead loading is developed by manipulating the initial tension of the main cable. Then the time-history dynamic analysis method is used to compute the seismic responses of the bridge under longitudinal,lateral and vertical excitations,respectively.Finally a comparison between the responses of the bridge subjected to uniform and nonuniform seismic ground motions is drawn.The result indicates that the longitudinal nonuniform excitation may increase the response of the bridge,and that the lateral or the vertical excitation may increase or decrease the responses of the different parts of the suspension bridge.
引文
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[3]Abdel-Ghaffar AM,Rubin LI.Response of suspension bridges to travelling earthquake excitations:Part ii.Lateral response[C]//Preprints-1982 ASCE National Convention Las Vegas,NV:ASCE.1982.
[4]Abdel-Ghaffar A M,Stringfellow R G.Response of suspension bridges to travelling earthquake excitations:Part i.Vertical response[J].SoilDynamics and Earthquake Engineering,1984,3(2):62-72.
[5]Dumanoglu A A,Severn R T.Seismic response of modern suspension bridges to asynchronous vertical ground motion[C]//Proceedings of the In-stitution of Civil Engineers.London,1987.
[6]Dumanoglu A A,Severn R T.Seismic response of modern suspension bridges to asynchronous longitudinal and lateral ground motion[C]//Pro-ceedings of the Institution of Civil Engineers.London,1989.
[7]胡世德,范立础.江阴长江公路大桥纵向地震反应分析[J].同济大学学报(自然科学版),1994,22(4):433-438.
[8]范立础.大跨度桥梁抗震设计[M].北京:人民交通出版社,2001.
[9]王君杰,范立础.规范反应谱长周期部分修正方法的探讨[J].土木工程学报,1998,31(6):49-55.
[10]周雍年,周正华,于海英.设计反应谱长周期区段的研究[J].地震工程与工程振动,2004,24(2):15-18.
[11]朱昱,冯启民.地震加速度相位差谱分布的数字特征[J].地震工程与工程振动,1993,13(2):30-37.
[12]朱昱,冯启民.相位差谱的分布特征和人造地震动[J].地震工程与工程振动,1992,12(1):37-44.
[13]屈铁军,王君杰.空间变化的地震动功率谱的实用模型[J].地震学报,1996,18(1):55-62.
[14]陈仁福.大跨悬索桥理论[M].成都:西南交通大学出版社,1994.
[2]Abdel-Ghaffar A M,Rubin L I.Suspension bridge response to multiple-support excitations[J].ASCE J.Eng.Mech.Div.,1982,108(EM2):419-435.
[3]Abdel-Ghaffar AM,Rubin LI.Response of suspension bridges to travelling earthquake excitations:Part ii.Lateral response[C]//Preprints-1982 ASCE National Convention Las Vegas,NV:ASCE.1982.
[4]Abdel-Ghaffar A M,Stringfellow R G.Response of suspension bridges to travelling earthquake excitations:Part i.Vertical response[J].SoilDynamics and Earthquake Engineering,1984,3(2):62-72.
[5]Dumanoglu A A,Severn R T.Seismic response of modern suspension bridges to asynchronous vertical ground motion[C]//Proceedings of the In-stitution of Civil Engineers.London,1987.
[6]Dumanoglu A A,Severn R T.Seismic response of modern suspension bridges to asynchronous longitudinal and lateral ground motion[C]//Pro-ceedings of the Institution of Civil Engineers.London,1989.
[7]胡世德,范立础.江阴长江公路大桥纵向地震反应分析[J].同济大学学报(自然科学版),1994,22(4):433-438.
[8]范立础.大跨度桥梁抗震设计[M].北京:人民交通出版社,2001.
[9]王君杰,范立础.规范反应谱长周期部分修正方法的探讨[J].土木工程学报,1998,31(6):49-55.
[10]周雍年,周正华,于海英.设计反应谱长周期区段的研究[J].地震工程与工程振动,2004,24(2):15-18.
[11]朱昱,冯启民.地震加速度相位差谱分布的数字特征[J].地震工程与工程振动,1993,13(2):30-37.
[12]朱昱,冯启民.相位差谱的分布特征和人造地震动[J].地震工程与工程振动,1992,12(1):37-44.
[13]屈铁军,王君杰.空间变化的地震动功率谱的实用模型[J].地震学报,1996,18(1):55-62.
[14]陈仁福.大跨悬索桥理论[M].成都:西南交通大学出版社,1994.
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