Analysis Of Structure Analysis And Temporary Pier Reinforcement Scheme For Large Urban Interchange

With the rapid development of urban transportation in China,The emergence of urban overpass is an inevitable choice for the development of urban road traffic.As a common part of urban interchange,the city interconnects with the island bridge and its advantages of strong transportation capacity,reasonable structure,beautiful appearance,it has been widely used in urban transportation,tunnel transportation,expressway transportation and other fields at home and abroad.However around the island as a special kind of small radius curved girder bridge,with the curved girder bridges and general mechanical characteristics at the same time,same as for the closed curve girder bridge,has a larger central Angle,should not be ignored.The influence of the whole ring structure has its particularity in the mechanical characteristics.So it is necessary to island bridge on the basis of existing curve beam bridge analysis theory for targeted research.In this paper,the structure characteristics of the upper and lower part of large ring island overpass and the analysis of temporary reinforcement measures are studied in detail.The main work and conclusions are as follows:(1)The stress behavior and deformation of the girder bridge and the three span continuous curves are summarized.The calculation shows that under constant load and vehicle load,the stress and deformation of the beam bridge of the simple support curve are the same with that of the three-span continuous curved girder bridge.Its torque is the smallest at the edge of the bridge,and it reaches the maximum at the center line and gradually increases from the edge to the center line.And its displacement is the largest on the outside edge of the curved bridge,and the inner edge is the smallest,which decreases from the outside edge of the curved bridge to the medial edge.(2)Based on the model of girder bridge,the stress and displacement characteristics and distribution of the upper structure of the girder bridge under constant load and vehicle load are analyzed.Analysis showed that the distribution rule,the island bridge and ordinary small radius curve beam bridge,its minimum torque on the edge of the main girder,the center line of the peak,the increased gradually from the edge to the center line.And its displacement is the largest on the outside edge of the curved bridge,and the inner edge is the smallest,which decreases from the outside edge of the curved bridge to the medial edge.On value,compared with common curved girder bridge,around the island bridge girder bending moment and torque decreases by 15%,and the displacement of the reduced 20%,known around the island on the stress and deformation of bridge structure has certain advantages.(3)Based on the finite element method,the influence of curvature radius on the mechanical behavior and deformation of girder bridge structure is studied.Through calculation under dead load and vehicle load,different radius of the curved girder Bridges around the island the size of the internal force and displacement,can draw: circle curve bridge with ordinary small radius curve beam bridge is similar,are greatly influenced by radius,and when its radius within 60 m,the influence of the radius on the internal force and deformation is especially significant.(4)Based on circle curve beam bridge model,the department around the island bridge structures and the temporary reinforcement measures are analyzed,and through the roundabout analysis and temporary pier and strengthening of bridge piers control section of strength and deformation calculation.It can be seen from the analysis that the overall rotation and deviation of the main girder of the island bridge will tilt the pier and bear the greater torque,which will lead to the damage of the pier.the temporary pier reinforcement,can through the reinforcement calculation of force and deformation of whether meet the specification requirements,to determine the effectiveness of the proposed temporary reinforcement measures,and verify the feasibility of temporary pier on the damaged bridge pier inside decorate and rationality.