摘要
基于非线性接触有限元数值模拟技术建立高精度落石-桥梁碰撞模型,对不同参数下桥墩的动态响应和破坏模式进行参数分析,主要研究的参数包括:桥墩上部质量、桥墩箍筋间距、落石质量与速度以及撞击位置。分析了我国规范给出的建议桥墩抗撞能力计算方法,并与实际抗撞能力对比。研究发现:落石高速撞击下桥墩的破坏形式以弯曲破坏为主,但是上部结构质量和落石速度的增加和撞击位置的改变会使桥墩的破坏形式由弯曲破坏向剪切破坏转变。落石冲击桥墩上部造成的破坏程度相比其他位置小,改变撞击方向会显著影响撞击点上方的桥墩侧向位移。我国公路桥梁抗震设计细则公式给出的计算方法低估了桥墩实际的抗撞能力,轴压力对桥墩的抗撞性能有明显提升,建议考虑在计算公式加入轴压力因素。
Based on the non-linear contact finite element numerical simulation technique,a high-precision rockfall-bridge collision model is established,and the dynamic response and failure mode of bridge piers under different parameters are analyzed.The main parameters include:the mass of the upper part of the pier,the spacing of the stirrups of the pier,the mass and velocity of the rockfall and the impact position.The proposed calculation method of pier resistance in China is analyzed in comparison with the actual one.It is found that bending failure is the main failure mode of bridge pier under high-speed impact of falling rocks,however,the increase of superstructure mass and rockfall velocity and the change of impact position will change the failure mode from bending failure to shear failure.The damage degree caused by falling rock impact on the upper part of the pier is smaller than that at other locations,and the lateral displacement of the pier above the impact point is affected significantly by changing the impact direction.The calculation method given in the seismic design formula of Chinese highway and bridge underestimated the actual collision capacity of the pier and significantly improved the collision performance of the pier.It is suggested to consider the axial pressure factors in the calculation formula.
作者
王郴
WANG Chen(Engineering College,Sichuan Normal University,Chengdu 610101,China)
出处
《东莞理工学院学报》
2021年第5期87-97,117,共12页
Journal of Dongguan University of Technology
关键词
桥梁
落石撞击
破坏模式
抗撞能力
等效碰撞力
bridge
rockfall impact
failure mode
resistance to impact
equivalent impact force
