双层钢桁梁斜拉桥振型模态及地震响应特征研究

为研究典型双层钢桁梁斜拉桥的振型模态及地震动响应特征,建立了三维精细化有限元模型,并选取1条人工波和4条天然波分别作为输入地震荷载以模拟双层钢桁梁的地震响应过程.结果表明,桥梁整体为长周期结构体系,一阶自振周期为8.11 s,基本振型特征为主梁横弯、主梁纵飘和横飘、反对称横弯.不同地震波作用下桥梁主要结构的位移峰值、内...

Modal Analysis and Seismic Response of the Steel Truss Cable-stayed Bridge with Double Deck

In order to study the vibration modal and seismic response of the typical steel truss cablestayed bridge with double deck,a refined numerical model is built.In addition,one artificial earthquake motion and four natural earthquake motions are selected as input motions to simulate the earthquake response of the cable-stayed bridge with double deck.According to the results of numerical simulation,it is concluded that the bridge has a long self-vibration period with the first vibration period being 8.11 s.In addition,the deformation models of the main vibration modal are the main bridge transverse bending,horizontal drifting,longitudinal drifting and antisymmetric transverse bending.The cases subjected to different earthquake motions show similar distributions of displacements and internal forces.While the cases under the artificial motion and El Centro motions with more long-period earthquake content show larger internal forces,compared to other three cases.Moreover,in the deformation cases of vertical bending,vertical reverse bending and horizontal transverse bending,larger stresses occur at the connecting areas,including web and the longitudinal beam,the web and the welded plate.The axial forces of the cable stayed under different seismic waves show the distribution pattern of U-shape.