平面弯梁桥地震响应特征与抗震对策研究  

Seismic response features and anti-seismic countermeasures of horizontally curved girder bridge

作　　者：范鑫 徐略勤[1,2] 孙榕徽 FAN Xin;XU Lueqin;SUN Ronghui(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]重庆交通大学省部共建山区桥梁及隧道工程国家重点实验室,重庆400074

出　　处：《地震工程与工程振动》2021年第4期177-187,共11页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(51978113);重庆市自然科学基金项目(CSTC2019JCYJ-MSXMX0691);重庆市研究生科研创新项目(CYS21346)。

摘　　要：为了揭示平面弯梁桥的地震响应特征,探讨行之有效的抗震对策,以在汶川地震中严重损毁的百花大桥第五联为研究对象,通过三向输入两组汶川实际地震波,研究了百花大桥第五联上部结构位移响应和下部结构应变响应特征,分析了百花大桥损毁原因,据此提出了相应的抗震对策并进行对比验证分析。研究表明:限位能力不足和支座布置不合理使百花大桥第五联出现了以固定墩为中心的平面转动,且主梁一端的径向偏移会加重另一端的切向偏移;固定墩底钢筋应变响应明显大于其他墩柱,其纵筋接近屈服,且最大应变位置大都与桥梁径向形成30°左右的夹角;引入改进抗震对策后,主梁、支座及桥墩位移显著下降,其中16#固定墩左右柱不同步位移下降超过90%,通过将固定墩的地震能量转移至具有恢复力机制的交界墩,使得各墩间能量分配更加均衡、合理。To reveal the seismic response characteristics of horizontally curved girder bridge and explore effective anti-seismic measures,the displacement response and strain response characteristics of superstructure and substructure of the fifth connection of Baihua bridge were studied by inputting two groups of Wenchuan actual seismic waves in three directions.Based on the analysis of the damage causes of Baihua bridge,the corresponding seismic countermeasures were put forward and compared.The results show that:due to the lack of limit capacity and unreasonable bearing arrangement,the fifth connection of Baihua bridge has an in-plane rotation centered on the fixed pier,and the radial offset of one side of the girder will aggravate the tangential offset of the other side;the strain of the reinforcement at the bottom of the fixed pier is significantly greater than that of other piers,the longitudinal reinforcement closely yielded,and the maximum strain positions mostly form an angle of about 30°with the bridge radial direction;while,The displacement of girders,supports and piers decreased significantly on the condition of taking anti-seismic measures,especially the unsynchronized displacement of the left and right columns of 16#fixed pier decreased by more than 90%;through transferring the seismic energy of fixed pier to the junction pier with restoring force mechanism,the energy distribution among the piers became more balanced and reasonable.

关 键 词：平面弯梁桥 抗震对策 平面转动 墩-梁位移 钢筋应变 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]