桥墩型式对大跨公路连续刚构桥车桥耦合振动响应的影响

Influence of Bridge Pier Type on Vehicle-Bridge Coupling Vibration Response of Long-span Highway Continuous Rigid Frame Bridge

目的以广东省某一高等级公路大桥为研究对象,分析桥墩型式对车桥耦合动力响应的影响,探究桥梁具有较小动力响应的桥墩型式。方法将三轴汽车简化为空间三维弹簧-质量-阻尼体系,建立桥梁的有限元模型,基于模态综合法和Newmark-β算法求解桥梁的振动响应,考虑桥面不平顺、车辆匀速行驶及加速行驶、横桥向车辆数量对桥梁中跨跨中和桥梁墩顶动力响应的影响。结果薄壁空心墩桥梁的位移响应和四柱墩桥梁弯矩响应最大,而双薄壁墩桥梁的位移响应和弯矩响应均为最小;双薄壁墩桥梁与其他桥墩型式桥梁相比,其位移响应最大降低67%,弯矩响应最大降低100%。结论桥墩型式对桥梁振动响应的影响明显,不同桥墩型式的桥梁动力响应差值较大;三种桥墩型式桥梁中,双薄壁墩桥梁的动力响应最小,双薄壁墩能有效降低桥梁的动力响应。

A certain highway bridge in Guangdong province is studied in order to analyze the influence of bridge pier type on the vehicle-bridge coupling dynamic response,and explore the bridge pier form with less dynamic response.The three-axis vehicle was simplified into a three dimensional spring-mass-damping system and the finite element model of the bridge was established.Based on the modal synthesis method and Newmark-β algorithm,the vibration response of the bridge was calculated,and the influence of bridge deck roughness,vehicle uniform speed and acceleration,transverse bridge to the number of vehicles on the dynamic response of the bridge was considered.The results show that the displacement response of the thin-walled hollow pier bridge and the bending moment response of the four-column pier bridge are the largest,while the displacement response and bending moment response of the double-thin-walled pier bridge are the smallest.Compared with other pier types,the displacement response and bending moment response of the double-thin-walled pier bridge are reduced by 67%and 100%respectively.Therefore,the influence of pier type on the vibration responses of bridge is obvious,and the difference of dynamic responses between different pier types is large.Among the three types of bridge piers,the dynamic responses of the double-thin-walled pier bridge are the smallest,and the double thin-walled pier can effectively reduce the dynamic responses.