摘要
近断层地震会给桥梁带来严重损害,其方向脉冲及竖向地震动效应日益引起研究者注意。以高速铁路多跨简支梁桥为研究对象,建立高烈度区地震作用下的非线性全桥模型,计算了水平及竖向地震作用下桥梁的弹塑性响应。结果表明:近断层地震下桥墩进入弹塑性阶段,刚度的改变其自振周期随之改变。相比远断层地震而言,近断层地震以其较大的脉冲周期与进入弹塑性的桥梁相耦合,将加剧桥梁的非线性响应。考察了竖向地震动对桥梁地震性能的影响,通过轴力变化改变影响桥墩滞回性能,增加塑性区变形,但不会导致墩顶横向位移的增加。建议设计时采用近断层地震因子及合适的竖向地震动参数考虑近断层效应的影响。
Long‐period pulse and vertical components in near fault earthquakes have been known to cause significant damage to bridge structures ,which have increasingly been the topics of lots of researchers recently .The nonlinear global model of the multi‐span simply supported bridge in a high seismic region is set up ,the elastic‐plastic seismic responses of bridge subjected to the combined effect of vertical and horizontal earthquakes are calculated .The calculation results show that ,the natural period of the bridge will increase with the stiffness of bridge decreasing when the bridge pier step into the nonlinear state under the near fault earthquakes .As compared to far field earthquakes ,the near fault earthquakes with the longer pulse period will inter‐action with the elastic‐plastic bridge ,which will in general cause more damaged seismic response .Additionally ,emphasis is placed on the importance of considering the vertical earthquakes on the seismic assessment of the bridge .The greater vertical earthquake will influence the hysteric performance of the bridge piers by the axial force fluctuations ,Extend plastic hinge for‐mations ;While it cannot correspondingly result in the increase of the lateral displacement of the piers .The near fault earth‐quake factor and the proper vertical ground motion parameter can be proposed to consider the influence of near fault earth‐quakes .
出处
《振动工程学报》
EI
CSCD
北大核心
2016年第4期704-713,共10页
Journal of Vibration Engineering
基金
江苏省第十批"六大人才高峰"高层次人才选拔培养项目(2013-JZ-005)
国家重点基础研究发展计划(973计划)(2013CB036305)
江苏省自然科学基金资助项目(BK20161337)
关键词
高速铁路桥梁
竖向地震
速度脉冲
非线性地震反应
近断层地震因子
high-speed railway bridge
vertical earthquakes
velocity pulse
nonlinear seismic response
near fault earthquake factor
