The Research On Stiffiness Evaluation Standard Of Long-span Rail-cum-road Cable-stayed Bridge

In recent years,with the expansion of city scale and the development of rail transit,highway and urban rail transit construction Bridges are constantly emerging.The stiffness design of long-span Bridges affects the dynamic performance of Bridges and the construction cost,however,the regulation on the rigidity of bridges is aimed at small and medium span bridges.The characteristics of train vehicles,characteristics of vehicles and Bridges are not fully considered.Based on this,the project background is The Sixth Luzhou Yangtze River Bridge of rail-cum-road bridge.The criterion of design rigidity of the bridge is studied with VBWD.There are the main lines:(1)This paper mainly introduces the development of cable-stayed Bridges at home and abroad,research overview of vehicle-bridge coupling vibration,and standards for the development of bridge rigidity,and research background and main research content.(2)Highway vehicle model is established,13 degrees of freedom respectively two car shaft model and 17 degrees of freedom of three-axis vehicle model,vehicle movement equation,simulated the four level road surface roughness spectrum was compared with specification,and then established the rail vehicle model,establish equation of motion,based on the six levels of spectrum of track irregularities was simulated.(3)The wind field parameters are determined according to the specifications,and the pulsating wind field is simulated numerically.The three-component force coefficient of the bridge is measured by wind tunnel test,and the wind load is determined.(4)With six luzhou Yangtze river bridge as the engineering background,to simulate the two bridge vehicle arrangement,the deterministic and stochastic flow of traffic,and to analyze the dynamic characteristics of the bridge,based on two kinds of traffic function out of the car-bridge coupled vibration response analysis of Bridges and trains-car-bridge-the wind under the coupled vibration of the car and the comparison of the safety and comfort of the running rail vehicles,obtained the reasonable stiffness analysis using deterministic traffic flow and to sex control of railway vehicles.(5)Consider pulsating wind,cars,and the role of railway vehicles,the bridge on the vertical and lateral stiffness change of bridge response and rail vehicle course evaluation index,based on line assessment results in male tracks amphibious cablestayed bridge is reasonable stiffness evaluation standard research,the reasonable stiffness limit while luzhou changjiang river six bridge,the vertical bending cross ratio of 1/838,beam Angle(unilateral)was 0.175‰,the horizontal amplitude of 17/f(mm),beam Angle(unilateral)was 0.15‰.