Research On Stress Performance Design Of The Large Span Bridge Structure

High-rise building has various forms at present,mechanical properties of bridge structure connected with towers through beam or steel truss are complex,the torsion effect,horizontal and vertical earthquake effect are significant under earthquake or wind vibration,collided slump even dropping damage often occurs,this paper deeply studied the calculation method of bridge structure,connected position,the bridge span and calculation of bridge bearing and so on.The influence on mechanical characteristics is worked out and according to the reasons,structure vibration control technology is studied for the purpose of energy dissipation and improvement of comfort.We provide theoretical support and reference for the design of long-span bridge structure.1)either symmetric or asymmetric structure bridge structure,the location of the bridge has no effect on the dynamic performance of the bridge,or weak effect can be ignored,showing the position of weak connection bridge structure of tower body structure has no effect on the macro.Bridge spans the impact of factors on the cycle of tower structure is mainly after the fourth order vibration mode.2)the internal force of the bridge as the bridge floor where the first increases then decreases,about one-third of the peak tower height,relative to the maximal displacement increased with the rising of the position.Bridge axial force increases with the increase of span,10 to 20 m small axial force can be ignored,20 m to 40 m when axial force increases rapidly,40 m and 60 m sharp increase.3)tower stiffness changes,even the bridge's internal force increases with the increase of stiffness of tower,even the bridge frame shear structure internal force is greater than the internal force of frame structure,basically relative maximum sliding displacement of sliding support as the main tower increases with the decrease of stiffness,the smaller the stiffness and structural system,the change in value,the more sensitive.4)friction pendulum bearing in 3200 kn/m,curvature radius of 1.5 m or so parameters can achieve the optimal effect,when the stiffness of the smaller towers and the difference of asymmetric tower tower system,can support the overall coordination effect,the structure of the translation-torsion coupling for bridge structure is good effect,more sensitive to reduce the displacement and internal force.5)in a setting two weakly connected bearing two damper damper device.Using time history analysis method to calculate the bearing displacement and even the bridge internal force are reduced60% of the good results,bearing displacement within the flame to reduce to 400 mm,so the friction pendulum bearing joint and damper device can play a good limit damping effect.