Analysis Of Lateral Displacement Of Curved Girder Bridge Considering Friction Sliding Of Bearing Under Automobile Centrifugal Force

With the rapid development of the transportation industry,highway and urban threedimensional traffic have become increasingly demanding on road alignment,so curved girder bridges have been widely used.Due to the irregular space shape,the curved girder bridge is easy to appear bearing slippage,emptying of the bearing,and excessive lateral displacement of the beam in the course of operation.In severe cases,the beam may even overturn.The automobile centrifugal force is the main factor causing lateral displacement of curved girder bridge.In order to accurately calculate the lateral displacement of the beam under the automobile centrifugal force,the simplified three-dimensional sliding bearing unit was established to analyze the lateral displacement of the curved beam bridge considering the friction slip of the bearing based on the friction slip performance analysis of the plate rubber bearing.And the control measures of the lateral displacement of the curved beam bridge were proposed based on the analysis of the influence of the limiting device parameters.The main research contents and conclusions are as follows.(1)Through the calculation and analysis of the shear stiffness of the plate rubber bearing,the accuracy of the refined solid model was verified.On this basis,the solid contact model between the bearing and the beam was established,and the friction sliding property of the plate rubber bearing was analyzed.The results show that with the increasing of the horizontal displacement of the beam,the bearing deformation is divided into two stages.The first stage is the elastic shear deformation of the bearing before the relative sliding between the bearing and the beam.The second stage is that after the the relative sliding between the bearing and the beam occurs,the shear deformation of the bearing does not increase and the sliding of the bearing increases gradually.(2)Based on the analysis of the friction sliding property of the plate rubber bearings,the mechanical model of bearing friction slip considering the ratio of static and dynamic friction coefficients is proposed,and the mechanical model of bearing slip under different conditions is summarized.The solid model of the bearing is simplified as the sliding bearing element model composed of three springs,and the accuracy of the sliding bearing element model is verified.(3)The model of curved girder bridge considering friction sliding of bearing was established,and the transverse vibration analysis of the curved beam bridge under the centrifugal force of the moving automobile was carried out through the transient dynamic analysis function of the finite element software ANSYS.The effects of vehicle speed,vehicle weight,pier height and radius of curvature on the lateral displacement of curved beam bridges were studied.The results show that the bearing on the inner side of the abutment is prone to frictional slip when the automobile centrifugal force is large.The influence of vehicle speed on the lateral displacement of the main beam is greater than that of the vehicle weight.To control the lateral displacement of the curved beam bridge,the speed limit should be the preferred measure.The pier height has a significant effect on the radial displacement of the pier top,but has little effect on the displacement of the pier top support.The influence of radius of curvature on the lateral displacement of curved beam bridge is mainly caused by the change of centrifugal force.When the centrifugal force is a fixed value,the radius of curvature has almost no effect on the peak value of lateral displacement of the main beam.(4)By adding the simulation of the limiting device to the curved girder bridge model considering the friction sliding of the bearing,the influence of the limiting device parameters on the lateral displacement control of the curved girder bridge is analyzed.The results show that the initial clearance and impact stiffness have a great influence on the lateral displacement of the main beam and the bending moment at the bottom of the pier.The parameters of the limiting device should be reasonably selected on the basis of effectively controlling the displacement of the main beam and avoiding the appearance of larger internal force in the substructure.