Study On The Reinfocement For No.5 Of Sunshui Bridge Of Chengkun Railway

This thesis analyze the effects which come from the existing disease on prestressed concrete hinged cantilever girder on the beam body of the No.5 SunShui bridge on Chengkun railway. It combines the methods of bridge conventional test and theoretical calculation to analysis the existing disease. According to the basic condition of this bridge and successful reinforcement experience home and abroad, three reinforcement methods are proposed: two-span continuous beam scheme with increased piers, four-span continuous beam scheme with increased piers and scheme, and increases the section in mid-span beam segment. Through theoretical calculation and comparison of these three schemes, the feasibility of two-span continuous beam scheme with increased piers is confirmed.The main contents and achievements of this thesis are as follows:(1).Through the analysis of existing structure design and field test results, the characteristics and causes of the cracks existing in the beam body of the main bridge as well as the necessity of reinforcement are confirmed.(2) On the basis of successful bridge reinforcement experience home and abroad, three reinforcement schemes for the crack disease in the beam body are selected as the main research contents.(3) By the general analysis for construction stage and serve stage of the existing structure as well as the detail finite element analysis of the beam segment, the impact effect of the shear hinge in the main bridge is verified as the main reason for the crack disease of the beam body.(4) Static calculation, dynamic analysis as well as seismic response analysis are done to study the two-span continuous beam scheme with increased piers. Then the serve stage of the girder after reinforcement is evaluated.(5) Through the detail analysis of the beam segment that is reinforced by enlarging the section area, a conclusion is drawn to evaluate the overall stress and local stress of the beam segment near to the shear hinge.(6) By the comparison of the technical and economical feasibility for these three reinforcement schemes, two-span continuous beam scheme with increased piers is chosen as the optimum scheme.