混合体系多塔斜拉桥竖弯刚度评估动力学理论

基于斜拉桥的受力特点和形状特征,提出了用于混合体系多塔斜拉桥面内竖弯刚度评估的多梁离散弹簧动力学模型.首先,在课题组相关成果的基础之上,介绍了采用传递矩阵法对不同体系斜拉桥的处理方式.然后,通过使用连续性条件和边界条件,建立了混合体系多塔斜拉桥竖弯刚度评估的基本理论.最后,以赤石大桥为例,建立了相应的有限元模型,并将本文方法算出的频率与有限元和实测得到的频率进行对比,表明本文方法的正确性,可用于混合体系多塔斜拉桥面内竖弯刚度的评估.

DYNAMIC THEORY FOR EVALUATION ON VERTICAL BENDING STIFFNESS OF MULTI-TOWER CABLE-STAYED BRIDGE WITH HYBRID SYSTEM

Based on the configuration and mechanical characteristics of the cable-stayed bridge, a dynamic multi-beam dynamic model with discrete springs is proposed for evaluating the in-plane vertical bending stiffness of the multi-tower cable-stayed bridge with hybrid system. First, based on the relevant achievements of our group, the treatment methods of cable-stayed bridges with different systems by transfer matrix method are introduced. Then, by using the continuity and boundary conditions, the basic theory for the evaluation on the vertical bending stiffness of the multi-tower cable-stayed bridge with hybrid system is established. Finally, taking the Chishi bridge as an example, the corresponding finite element model is established and the frequencies calculated by the method in this paper are compared with those by the finite element method and field measurement. The results show that the method in this paper is feasible and can be used for the evaluation of the vertical bending stiffness in the multi-tower cable-stayed bridge with hybrid system.