Study On Sliding Of Main Beam Of Highway Continuous Slope Bridge

Sliding along the slope of the main beam is one of the common diseases of continuous slope bridges on the highway,which seriously affects the normal use of the bridge.At present,the research on the influence of car load parameters on the slope of the main beam is mainly through statics,the calculation of the bearing force of the slope bridge is not accurate enough,and the friction-slip characteristics and internal stress distribution of the top and bottom contact surfaces of the bearing are not studied.To this end,this paper considers the effect of vehiclebridge coupling vibration to accurately calculate the bearing force,analyzes the several main factors that affect the anti-sliding stability of the bearing,and establishes a refined threedimensional solid model of the bearing to study the ideal bearing and the defect of the bearing under the interface friction slip characteristics and internal stress distribution.Through the analysis of bearing anti-sliding stability,the study of friction-slip characteristics at the bearing interface,and the internal stress distribution,the mechanism of sliding along the slope of the beam of the continuous slope bridge of the highway is revealed together,and the longitudinal push-reset technology of the beam is introduced.The main research contents and conclusions of this article are as follows:(1)A numerical analysis method for vehicle-bridge coupling vibration response of highway bridges based on ANSYS platform considering vehicle braking effect and road roughness is proposed,and the vehicle-bridge coupling vibration analysis under arbitrary braking of the vehicle is realized,and verified the correctness and reliability of the program by an example.(2)The correctness of the 3×25m prestressed concrete continuous small box girder beam model and the two-axis space vehicle model were verified.On this basis,an vehicle-bridge coupling vibration system considering car braking was established,and several factors influencing the anti-sliding stability of the bearing,such as vehicle load value,vehicle braking position,different vehicle speed,longitudinal slope value and road roughness,were analyzed and studied.The research results show that with the increase of the vehicle load value,the increase of the vehicle speed,and the deterioration of the road surface,the anti-sliding stability of the bearing decreases,and the bearing at the center beam easily slips first.(3)Based on ANSYS,a refined three-dimensional solid model of plate rubber bearing was established.The model was verified by simulating axial compression performance test and shear performance test,the interface friction-slip characteristics and internal stress distribution under ideal bearing and bearing defects were analyzed.Study the influence of bearing defects on the slope of main beam along the slope.The research results show that the uneven compression of the bearing and the vacant area of the bearing have little effect on the slip of the main beam;The uneven compression of the bearing and the vacant bearing reduce the displacement of the bearing;The degree of peeling of rubber and steel plate increases with the uneven compression of the bearing and the increase of the vacant area of the bearing,which is harmful for the shear stress of the bearing;the maximum horizontal and vertical stress of each layer of steel plate and rubber decrease with the uneven compression and the increase of the vacant area of the bearing,which has a certain unloading effect on the internal stress of the bearing.The research results of this paper have important practical and social significance for the understanding of the mechanism of sliding along the slope of the main beam,ensuring the safety of the slope bridge during operation,extending the service life,and reducing economic losses.