Analysis for Spatial Dynamic Characteristics of High-pier Large-span Continuous Steel Structure Bridges

Dynamic characteristics of continuous steel structure bridges are prerequisite and basis of dynamic structural analysis for bridges.With one high-pier large-span continuous steel structure bridge as the object of research,this paper analyzes influences of its structural parameters on dynamic characteristics by establishing its finite element model by means of finite element software ANSYS.The analysis indicates that: 1) All-order vibration frequencies increase with increase of rigidity of girder,and frequency changes of side bending and vertical bending vibrations are more obvious and show less influence on longitudinal floating vibration mode;2) Changes of pier rigidity exhibit significant influences on side bending and longitudinal floating frequency,but relatively less influences on vertical bending frequency;3) Longitudinal constraint spring stiffness has no influences on all-order vertical and longitudinal frequencies,but can remarkably increase longitudinal frequency.