Abstract:To study the influence of the beam between pylons on the static and dynamic characteristics of cable-stayed bridges without backstays, taking a bridge without backstays as an example, four finite element models are set up to analyze the static and dynamic structural characteristics and seismic response of solid beams, big hollow beams, small hollow beams, and the structure without beams with the three-dimensional static and dynamic finite element method. The static calculation results show that in the four schemes, the cable tension of structure with solid beam under the most unfavorable load reaches the safety factor critical value. Moreover, the deflection of the main beam and the longitudinal deformation of the main tower decrease as the weight of the pylon beam increases. The shrinkage creep deformation value of the pylon without beams under long-term load deviates from the main span. The dynamic calculation results show that for the second scheme, the axial force and transverse bending moment value of the tower bottom are the largest. The transverse shear force is the largest for the fourth scheme, and the stiffness of the structure without beams is small, which makes the pylon prone to transverse instability. Considering the static and dynamic analysis results, construction convenience, and the maintenance of structures, it is suggested that the solid beam tower be used in the structure.