城际铁路变宽度连续箱梁桥的动力特性
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摘要
研究了变宽度连续箱梁桥在成桥状态下的动力特性.以某五跨变宽度连续箱梁桥为背景,建立整桥三维空间有限元模型,对大桥的模态进行分析,并选用50年超越概率分别为3%(E1)和10%(E2)两个水准的反应谱进行成桥阶段的地震响应分析.结果表明:E1,E2概率下,变宽度连续箱梁桥制动墩上的内力较大,且顺桥向地震荷载作用对制动墩的内力影响比横桥向地震荷载作用大,竖向地震荷载作用对桥墩轴力影响较大,而对桥梁上部结构位移影响不大,变宽度连续箱梁桥地震反应随桥墩高度增加而增强.建议桥梁设计时,重点考虑固定墩及固定支座的设计,并对固定墩底部进行加固处理,抗震分析时,慎重考虑地震荷载竖向分量取值.通过地震反应谱分析,在规范要求的地震荷载作用下,变宽度连续箱梁桥整体抗震性能良好,满足抗震设计要求.
Dynamic characteristics of a variable-width continuous box girder bridge under completion state were studied.Based on a five-span continuous box bridge with variable width of the inter-city railway between Zhengzhou and Xinzheng international airport,the model was established through finite element method and modal analysis was carried out.The space beam element model was used to simplify the calculation,focusing on the simulation of boundary conditions,stiffness and mass of the variable width continuous box girder bridge.In the seismic response analysis,stiffness in vertical and three rotational directions can simply hand because the response of the bearing horizontal stiffness was large to the earthquake.Main beams and piers used space beam element and bearing used spring element to simulate.Between the roof and floor of the main beam,rigid connection was used to simulate.Reference to the arrangement of prestressed steel beam,considering the actual situation of the beam,the whole bridge was separated by the way of finite element.Secondary dead loads including bridge deck pavement,railings,pipelines,etc were into quality.Piers were scattered as a beam element every 1 meter height direction to make the simulation of structure quality distribution more accurate which can improve the calculation accuracy.The whole bridge was divided into 709 nodes and 245 beam elements.Two levels of response spectrum that the exceeding probabilities were respectively 3% and 10% in 50 years were selected to analyze seismic response under finished state.Internal force and displacement were mainly calculated.The results show that the internal force on fixed pier is bigger than other piers'under the two exceeding probabilities.Earthquake loads along the bridge have more effect on internal force of fixed pier than earthquake loads cross the bridge.The vertical seismic load has a greater influence on the axial force generating in piers while it has a little effect on the displacement of superstructure of bridge.Seismic response is stronger when pier is higher.Earthquake load along the bridge mainly generates the displacement andshear force along the bridge,axial force,in-plane bending moment.Earthquake load cross the bridge mainly produces displacement and pier shearing force cross the bridge,out-plane bending moment.It is suggested that the design of fixed pier and fixed support should be mainly considered in bridge design and vertical seismic load values require serious consideration in seismic analysis.The bottom of the pier should be reinforced.Through the analysis of seismic response spectrum,the overall seismic performance of variable width continuous box girder bridge is good under earthquake loads in specification requirement which also meet requirements of seismic design.
Dynamic characteristics of a variable-width continuous box girder bridge under completion state were studied.Based on a five-span continuous box bridge with variable width of the inter-city railway between Zhengzhou and Xinzheng international airport,the model was established through finite element method and modal analysis was carried out.The space beam element model was used to simplify the calculation,focusing on the simulation of boundary conditions,stiffness and mass of the variable width continuous box girder bridge.In the seismic response analysis,stiffness in vertical and three rotational directions can simply hand because the response of the bearing horizontal stiffness was large to the earthquake.Main beams and piers used space beam element and bearing used spring element to simulate.Between the roof and floor of the main beam,rigid connection was used to simulate.Reference to the arrangement of prestressed steel beam,considering the actual situation of the beam,the whole bridge was separated by the way of finite element.Secondary dead loads including bridge deck pavement,railings,pipelines,etc were into quality.Piers were scattered as a beam element every 1 meter height direction to make the simulation of structure quality distribution more accurate which can improve the calculation accuracy.The whole bridge was divided into 709 nodes and 245 beam elements.Two levels of response spectrum that the exceeding probabilities were respectively 3% and 10% in 50 years were selected to analyze seismic response under finished state.Internal force and displacement were mainly calculated.The results show that the internal force on fixed pier is bigger than other piers'under the two exceeding probabilities.Earthquake loads along the bridge have more effect on internal force of fixed pier than earthquake loads cross the bridge.The vertical seismic load has a greater influence on the axial force generating in piers while it has a little effect on the displacement of superstructure of bridge.Seismic response is stronger when pier is higher.Earthquake load along the bridge mainly generates the displacement andshear force along the bridge,axial force,in-plane bending moment.Earthquake load cross the bridge mainly produces displacement and pier shearing force cross the bridge,out-plane bending moment.It is suggested that the design of fixed pier and fixed support should be mainly considered in bridge design and vertical seismic load values require serious consideration in seismic analysis.The bottom of the pier should be reinforced.Through the analysis of seismic response spectrum,the overall seismic performance of variable width continuous box girder bridge is good under earthquake loads in specification requirement which also meet requirements of seismic design.
引文
[1]阿卜杜拉.预应力混凝土连续梁桥的力学特性与关键技术研究[D].北京:北京交通大学,2014.ABDULLAH.Study on the mechanical properties and key technology of prestressed concrete continuous bridge[D].Beijing:Beijing Jiaotong Unibersity,2014.
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[3]李丰.连续梁桥地震响应分析及横向减隔震设计[D].西安:长安大学,2013.LI F.Transverse seismic mitigation isolation design and seismic response analysis of continuous beam bridges[D].Xi'an:Chang'an University,2013.
[4]赵志蒙.大跨径预应力混凝土连续梁桥抗震性能分析[J].内蒙古大学学报(自然科学版),2009,40(2):218-224.ZHAO Z M.Analysis on the earthquake resistant behavior of long-span prestressed concrete continuous girder bridge[J].Journal of Inner Mongolia University,2009,40(2):218-224.
[5]李登科.高墩大跨铁路桥梁动力特性分析[J].铁道建筑,2012(7):1-3.LI D K.Analysis on dynamic performance of large-span railway bridge with high piers[J].Railway Engineering,2012(7):1-3.
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[7]张怀静,潘旦光.变截面连续梁动力特性的半解析解法[J].北京科技大学学报,2008,30(6):590-593.ZHANG H J,PAN D G.Semi-analytic solution to dynamic characteristics of non-uniform continuous beams[J].Journal of University of Science and Technology Beijing,2008,30(6):590-593.
[8]魏俊龙.波形钢腹板箱梁斜塔无背索斜拉桥地震响应分析[J].河南科技大学学报(自然科学版),2013,35(3):64-68.WEI J L.Analysis on earthquake response of leaning tower without backstays cable-stayed bridge with corrugated steel webs box girder[J].Journal of Henan University of Science and Technology(Natural Science),2013,35(3):64-68.
[9]王炎,谢旭,申永刚.近场地震作用下铁路减震桥梁地震响应研究[J].铁道学报,2012,34(12):102-109.WANG Y,XIE X,SHEN Y G.Seismic response of isolated railway bridge subjected to near-fault ground motion[J].Journal of the China Railway Society,2012,34(12):102-109.
[10]LIN X K,ZHANG Q T,GUO Q T,et al.Dynamic finite element model updating of prestressed concrete continuous box-girder bridge[J].Earthquake Engineering and Engineering Vibration,2009,8(3):399-407.
[11]杨万里,李乔.动水压力对连续钢构桥梁地震响应的影响[J].西南交通大学学报,2012,47(3):373-378.YANG W L,LI Q.Effects of hydrodynamic pressure on seismic response of continuous rigid-framed bridge[J].Journal of Southwest Jiaotong University,2012,47(3):373-378.
[12]吕梁,梁斌,徐红玉,等.波形钢腹板箱梁剪切屈曲特性[J].河南科技大学学报(自然科学版),2015,36(3):70-75.LYU L,LIANG B,XU H Y,et al.Research on shear buckling property of box girder with corrugated steel webs[J].Journal of Henan University of Science and Technology(Natural Science),2015,36(3):70-75.
[13]周长青,赵锐,崔德永,等.独塔斜拉桥水滴型钢结构主塔力学特性[J].河南科技大学学报(自然科学版),2015,36(4):68-72.ZHOU C Q,ZHAO Y,CUI D Y,et al.Study on mechanical behavior of water-drop-shaped steel tower of cable-stayed bridge[J].Journal of Henan University of Science and Technology(Natural Science),2015,36(4):68-72.
[14]崔德永,徐红玉,梁斌,等.异型钢结构主塔斜拉桥的动力特性及地震响应分析[J].河南大学学报(自然科学版),2015,45(6):735-739.CUI D Y,XU H Y,LING B,et al.Dynamic characteristics and seismic response analysis of cable-stayed bridge of deformed steel structure main tower[J].Journal of Henan University(Natural Science),2015,45(6):735-739.
[15]GB 50111-2006.铁路工程抗震设计规范[S].北京:中国计划出版社,2009.GB 50111-2006.Code for seismic design of railway engineering[S].Beijing:China Planning Press,2009.
[2]王克海,李茜.桥梁抗震的研究进展[J].工程力学,2007,24(2):75-82.WANG K H,LI Q.Research progress on seismic design of bridges[J].Engineering Mechanics,2007,24(2):78-82.
[3]李丰.连续梁桥地震响应分析及横向减隔震设计[D].西安:长安大学,2013.LI F.Transverse seismic mitigation isolation design and seismic response analysis of continuous beam bridges[D].Xi'an:Chang'an University,2013.
[4]赵志蒙.大跨径预应力混凝土连续梁桥抗震性能分析[J].内蒙古大学学报(自然科学版),2009,40(2):218-224.ZHAO Z M.Analysis on the earthquake resistant behavior of long-span prestressed concrete continuous girder bridge[J].Journal of Inner Mongolia University,2009,40(2):218-224.
[5]李登科.高墩大跨铁路桥梁动力特性分析[J].铁道建筑,2012(7):1-3.LI D K.Analysis on dynamic performance of large-span railway bridge with high piers[J].Railway Engineering,2012(7):1-3.
[6]吴辉琴,王赞芝,涂辉,等.变截面连续梁动力特性的差分解法[J].广西大学学报(自然科学版),2010,35(1):101-104.WU H Q,WANG Z Z,TU H,et al.Finite-difference methods for calculating dynamic properties of variational continuous beams[J].Journal of Guangxi University(Natural Science Edition),2010,35(1):101-104.
[7]张怀静,潘旦光.变截面连续梁动力特性的半解析解法[J].北京科技大学学报,2008,30(6):590-593.ZHANG H J,PAN D G.Semi-analytic solution to dynamic characteristics of non-uniform continuous beams[J].Journal of University of Science and Technology Beijing,2008,30(6):590-593.
[8]魏俊龙.波形钢腹板箱梁斜塔无背索斜拉桥地震响应分析[J].河南科技大学学报(自然科学版),2013,35(3):64-68.WEI J L.Analysis on earthquake response of leaning tower without backstays cable-stayed bridge with corrugated steel webs box girder[J].Journal of Henan University of Science and Technology(Natural Science),2013,35(3):64-68.
[9]王炎,谢旭,申永刚.近场地震作用下铁路减震桥梁地震响应研究[J].铁道学报,2012,34(12):102-109.WANG Y,XIE X,SHEN Y G.Seismic response of isolated railway bridge subjected to near-fault ground motion[J].Journal of the China Railway Society,2012,34(12):102-109.
[10]LIN X K,ZHANG Q T,GUO Q T,et al.Dynamic finite element model updating of prestressed concrete continuous box-girder bridge[J].Earthquake Engineering and Engineering Vibration,2009,8(3):399-407.
[11]杨万里,李乔.动水压力对连续钢构桥梁地震响应的影响[J].西南交通大学学报,2012,47(3):373-378.YANG W L,LI Q.Effects of hydrodynamic pressure on seismic response of continuous rigid-framed bridge[J].Journal of Southwest Jiaotong University,2012,47(3):373-378.
[12]吕梁,梁斌,徐红玉,等.波形钢腹板箱梁剪切屈曲特性[J].河南科技大学学报(自然科学版),2015,36(3):70-75.LYU L,LIANG B,XU H Y,et al.Research on shear buckling property of box girder with corrugated steel webs[J].Journal of Henan University of Science and Technology(Natural Science),2015,36(3):70-75.
[13]周长青,赵锐,崔德永,等.独塔斜拉桥水滴型钢结构主塔力学特性[J].河南科技大学学报(自然科学版),2015,36(4):68-72.ZHOU C Q,ZHAO Y,CUI D Y,et al.Study on mechanical behavior of water-drop-shaped steel tower of cable-stayed bridge[J].Journal of Henan University of Science and Technology(Natural Science),2015,36(4):68-72.
[14]崔德永,徐红玉,梁斌,等.异型钢结构主塔斜拉桥的动力特性及地震响应分析[J].河南大学学报(自然科学版),2015,45(6):735-739.CUI D Y,XU H Y,LING B,et al.Dynamic characteristics and seismic response analysis of cable-stayed bridge of deformed steel structure main tower[J].Journal of Henan University(Natural Science),2015,45(6):735-739.
[15]GB 50111-2006.铁路工程抗震设计规范[S].北京:中国计划出版社,2009.GB 50111-2006.Code for seismic design of railway engineering[S].Beijing:China Planning Press,2009.