Dynamic Response Analysis Of Curved Continuous Girder Bridges And Research On The Identification Methods Of Bearing Separation

In recent years,with the continuous development of the modern transportation industry,the number of new bridges has been increasing,and more and more curved continuous girder bridges are used in urban interchange ramps,river crossings of expressways,and large-span bridge approach span.Curved continuous girder bridges are affected by the curvature of the girder,resulting in obvious "bending-torsion coupling" effects,making its dynamic response more complicated,and frequent bearing separation diseases under the influence of traffic load and foundation settlement.The bearing separation will cause the bias or overpressure of the remaining bearing,which will lead to uneven stress on the bridge as a whole and affect the operation safety of the bridge..In response to this problem,this paper takes a three-span curved continuous girder bridge as a background,establishes a vehicle-road-bridge rigid-flexible coupling system dynamic model,analyzes the bridge dynamic response,and research on the method of identifying bearing separation of curved continuous girder bridge based on the time-history statistics indexes of the original acceleration signals.The main part of this article are as follows:(1)The establishment of the dynamic model of the vehicle-road-bridge rigidflexible coupling system is realized.First,a 3×25 m curved continuous girder bridge finite element model is established,and based on the experimental parameters of a heavy-duty truck,a three-dimensional refined heavy-duty truck model was established using the multi-body dynamics software Simpack.Then the vehicle-bridge coupling dynamics equations are analyzed,and the dynamic model of the vehicle-road-bridge rigid-flexible coupling system is established using the method of Abaqus and Simpack co-simulation.Finally,the trigonometric series method is used to simulate the irregularities of the bridge deck in the time domain,which lays the foundation for further research.(2)Based on the dynamic model of the vehicle-road-bridge rigid-flexible coupling system,the dynamic response of the curved continuous girder bridge is analyzed,and the influence of factors such as vehicle speed,vehicle weight,vehicle eccentricity,bridge deck irregularity,and bridge deck pavement stiffness on the bridge displacement,torsion angle,impact coefficient and bearing reaction force are discussed.(3)In order to quickly assess the health status of curved continuous girder bridge bearings,a method for identifying bridge bearing separation based on time-history statistical indicators was proposed.First,extract the time-history statistical indicators of the acceleration signal of the bridge deck measurement point under the driving excitation.Then,by means of probability statistics,the confidence interval of each statistical indicator is obtained.Finally,the damage index is calculated according to the number of abnormal indicators at each measuring point,and it is comprehensively judged whether the bearing separation near the measuring point.In order to verify the effectiveness of the method,analysis and verification are carried out based on the established vehicle-road-bridge coupling rigid-flexible coupling dynamics model.