增设黏滞阻尼器加固铁路桥梁的减震控制分析
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摘要
研究目的:基于大地震中铁路桥梁因为墩梁横向位移过大造成的落梁等破坏,本文提出在T梁和墩顶之间增设黏滞阻尼器对桥梁进行减震控制的加固方案。以采用圆端型桥墩的某混凝土简支双片式T梁铁路桥为例,通过ANSYS软件建立桥梁结构模型,选取4条地震动记录,分析地震作用下不同墩高时桥梁的动力响应;选取两种液体黏滞阻尼器的加固布置方案,分析不同的阻尼器布置位置对桥梁墩顶的横向位移以及墩梁横向相对位移的影响规律,研究阻尼器不同设计参数对桥梁耗能减震的效果,结合阻尼器优化得到的参数并最终选定一种效果较好的加固方案。研究结论:(1) 8度罕遇地震作用下,墩顶位移和墩梁相对位移较大,超出了铁路桥梁的允许位移值;(2)随着墩高的增大,墩顶位移随之增大,而墩梁相对位移的变化规律不明显;(3)本铁路桥梁加固时液体黏滞阻尼器的推荐参数为阻尼速度指数a=0.3,阻尼系数C=5 000 k N·(s/m)a;(4)液体黏滞阻尼器能够显著降低地震作用下的墩顶位移和墩梁相对位移,消能减震作用显著;(5)本研究结论可用于既有铁路桥梁的抗震加固及减震控制。
Research purposes:Based on the failure of the railway bridge in great earthquakes because of the excessive lateral displacement of the pier and beam,this paper proposed the retrofit scheme of adding viscous dampers between T girder and the pier top to control the seismic vibration of the bridge.Taking a concrete simply supported double-plate T beam railway bridge with the circular end pier as an example,the bridge structural model is established by ANSYS software,and 4 ground motion records are selected to analyze the dynamic response of the bridge with different pier heights under seismic actions.Two layout schemes of liquid viscous dampers are selected,and the influence of different damper positions on the lateral displacement of the pier top and the relative displacement between pier top and beam is analyzed.The effects of different design parameters of the dampers on the energy dissipation of bridges are studied,and a better retrofit scheme is selected based on the optimized parameters of the dampers.Research conclusions:(1) The displacement of pier top and the relative displacement between pier top and beam are greater than the allowable value of the railway bridge under the 8-degree rare earthquake.(2) With the increase of pier height,the displacement of pier top increases,and the change rule the relative displacement between pier top and beam is not obvious.(3) The recommended parameters of liquid viscous dampers are damping speed exponent a=0.3 and damping coefficient C=5 000 kN·(s/m)afor this railway bridge retrofit.(4) The liquid viscous damper can significantly reduce the displacement of pier top and the relative displacement between pier top and beam under seismic action,and the energy dissipation effect is remarkable.(5) The research conclusion can be applied to the seismic control of the existing railway bridges.
Research purposes:Based on the failure of the railway bridge in great earthquakes because of the excessive lateral displacement of the pier and beam,this paper proposed the retrofit scheme of adding viscous dampers between T girder and the pier top to control the seismic vibration of the bridge.Taking a concrete simply supported double-plate T beam railway bridge with the circular end pier as an example,the bridge structural model is established by ANSYS software,and 4 ground motion records are selected to analyze the dynamic response of the bridge with different pier heights under seismic actions.Two layout schemes of liquid viscous dampers are selected,and the influence of different damper positions on the lateral displacement of the pier top and the relative displacement between pier top and beam is analyzed.The effects of different design parameters of the dampers on the energy dissipation of bridges are studied,and a better retrofit scheme is selected based on the optimized parameters of the dampers.Research conclusions:(1) The displacement of pier top and the relative displacement between pier top and beam are greater than the allowable value of the railway bridge under the 8-degree rare earthquake.(2) With the increase of pier height,the displacement of pier top increases,and the change rule the relative displacement between pier top and beam is not obvious.(3) The recommended parameters of liquid viscous dampers are damping speed exponent a=0.3 and damping coefficient C=5 000 kN·(s/m)afor this railway bridge retrofit.(4) The liquid viscous damper can significantly reduce the displacement of pier top and the relative displacement between pier top and beam under seismic action,and the energy dissipation effect is remarkable.(5) The research conclusion can be applied to the seismic control of the existing railway bridges.
引文
[1]陈克坚,袁明.汶川地震后对铁路桥梁抗震设计有关问题的思考[C]//2008年地震灾害对铁路的影响及对策学术研讨会论文集,2008:176-182.Chen Kejian,Yuan Ming.Thoughts on the Problems Related to Earthquake-resistant Design of Railway Bridge after Wenchuan Earthquake[C]//The Proceedings of 2008 Symposium on Earthquake Disaster Impacts on Railway and Countermeasures,2008:176-182.
[2]庄卫林,余翔,易志宏,等.简支体系桥梁的震害及抗震设计对策[J].桥梁建设,2008(4):61-64.Zhuang Weilin,Yu Xiang,Yi Zhihong,etc.Seismic Damage and Design Countermeasures of Simplysupported System Bridges[J].Bridge Construction,2008(4):61-64.
[3]周长东,高字,陈阳,等.应用阻尼器抑制铁路桥梁横向振动的研究[J].铁道工程学报,2018(5):52-57.Zhou Changdong,Gao Zi,Chen Yang,etc.Research on the Transverse Vibration Suppression of Railway Bridges by Using Damper[J].Journal of Railway Engineering Society,2018(5):52-57.
[4]GB 50111-2006,铁路工程抗震设计规范[S].GB 50111-2006,Code for Seismic Design of Railway Engineering[S].
[5]陈令坤,蒋丽忠,余志武,等.高速铁路简支梁桥地震反应特性研究[J].振动与冲击,2011(12):216-222.Chen Lingkun,Jiang Lizhong,Yu Zhiwu,etc.Seismic Response Characteristics of a High-speed Railway Simply Supported Girder Bridge[J].Journal of Vibration and Shock,2011(12):216-222.
[6]Tan R.Y.,Huang M.C.System Identification of a Bridge with Lead-rubber Bearings[J].Computers&Structures,2000(3):267-280.
[7]陈永祁.桥梁工程液体黏滞阻尼器设计与施工[M].北京:中国铁道出版社,2012.Chen Yongqi.Design and Construction of Liquid Viscous Devices for Bridge Engineering[M].Beijing:China Railway Publishing House,2012.
[8]Liu Lin,Zhang Xia,Yang Qingshan.Estimation of the Optimum Parameters of Fluid Viscous Dampers for Seismic Response Control of Highway Bridges[C]//Proceedings of the 29th Chinese Control Conference,2010:5705-5711.
[2]庄卫林,余翔,易志宏,等.简支体系桥梁的震害及抗震设计对策[J].桥梁建设,2008(4):61-64.Zhuang Weilin,Yu Xiang,Yi Zhihong,etc.Seismic Damage and Design Countermeasures of Simplysupported System Bridges[J].Bridge Construction,2008(4):61-64.
[3]周长东,高字,陈阳,等.应用阻尼器抑制铁路桥梁横向振动的研究[J].铁道工程学报,2018(5):52-57.Zhou Changdong,Gao Zi,Chen Yang,etc.Research on the Transverse Vibration Suppression of Railway Bridges by Using Damper[J].Journal of Railway Engineering Society,2018(5):52-57.
[4]GB 50111-2006,铁路工程抗震设计规范[S].GB 50111-2006,Code for Seismic Design of Railway Engineering[S].
[5]陈令坤,蒋丽忠,余志武,等.高速铁路简支梁桥地震反应特性研究[J].振动与冲击,2011(12):216-222.Chen Lingkun,Jiang Lizhong,Yu Zhiwu,etc.Seismic Response Characteristics of a High-speed Railway Simply Supported Girder Bridge[J].Journal of Vibration and Shock,2011(12):216-222.
[6]Tan R.Y.,Huang M.C.System Identification of a Bridge with Lead-rubber Bearings[J].Computers&Structures,2000(3):267-280.
[7]陈永祁.桥梁工程液体黏滞阻尼器设计与施工[M].北京:中国铁道出版社,2012.Chen Yongqi.Design and Construction of Liquid Viscous Devices for Bridge Engineering[M].Beijing:China Railway Publishing House,2012.
[8]Liu Lin,Zhang Xia,Yang Qingshan.Estimation of the Optimum Parameters of Fluid Viscous Dampers for Seismic Response Control of Highway Bridges[C]//Proceedings of the 29th Chinese Control Conference,2010:5705-5711.