摘要
以某高速铁路深水库区多跨矮塔斜拉桥为研究对象,建立全桥三维空间动力模型,按附加质量法考虑动水压力效应,采用非线性时程分析法研究动水压力对桥梁动力特性和地震响应的影响程度。结果表明:考虑动水压力作用后,结构自振频率减小、自振周期变长,高阶振型滞后出现;纵向地震作用下,动水使墩顶位移最大增长44%、弯矩最大增长25%、剪力最大增长45%;横向地震作用下,动水使墩顶位移最大增长9%、弯矩最大增长9.5%、剪力最大增长10.6%,动水对纵向地震反应的影响明显大于横向地震。因此在进行铁路大跨度深水桥梁抗震设计时,动水压力作用不可忽略。
Taking a multi-span low-pylon cable-stayed bridge in deep reservoir area of a high-speed railway as the research object,three dimensional dynamic model of the whole bridge is established.The effect of hydrodynamic pressure is considered by additional mass method,and the nonlinear time history analysis method is used to study the influence of hydrodynamic pressure on dynamic characteristics and seismic response of bridge.The results show that:(1)after considering the hydrodynamic pressure,the natural frequency of the structure decreases,the natural vibration period becomes longer,and the higher mode lag appears.(2)Under the action of longitudinal earthquake,the maximum increase of pier displacement,bending moment and shear force is respectively 44%,25%and 45%through hydrodynamic pressure.(3)Under the action of transverse earthquake,the maximum increase of pier displacement,bending moment and shear force is 9%,9.5%and 10.6%respectively.The influence of hydrodynamic pressure on the longitudinal seismic response is obviously greater than that on the transverse seismic response.Therefore,in the seismic design of long-span deep-water railway bridges,the effect of hydrodynamic pressure can not be ignored.
作者
张莹
ZHANG Ying(China Railway Shanghai Design Institute Group Co.Ltd.,Shanghai 200070,China)
出处
《铁道建筑技术》
2021年第6期110-113,共4页
Railway Construction Technology
基金
中国铁建股份有限公司科技研究开发计划项目(17-C45)。
关键词
高速铁路
矮塔斜拉桥
动水压力
地震响应
high-speed railway
low-pylon cable-stayed bridge
hydrodynamic pressure
seismic response
