| With the rapid development of bridge construction in my country,the prestressed concrete hollow slab beam with simple structure and convenient construction has become one of the bridge designers’ preferred bridge types.Once the hinge as the lateral force transmission structure between the slab and girder fails,it will affect the lateral distribution of the load,and then form the phenomenon of the veneer force,which greatly reduces the overall safety of the bridge.In the current overall inspection and maintenance of bridges,people pay attention to steel structures while ignoring concrete structures in terms of fatigue problems.In today’s increasing traffic volume and increasing traffic load,the structural performance of hinge joints of concrete hollow slab girder bridges has also degraded over time,resulting in fatigue safety problems.Therefore,the research on the evolution law of fatigue damage and the reinforcement scheme of the hinged joint of the hollow slab girder bridge has certain theoretical and practical value.Based on the concrete hollow slab girder bridges in some sections of the Beijing-Shanghai Expressway in Jiangsu Province,this paper conducts joint disease investigations,and analyzes the current main characteristics of joint joint diseases,the proportion of joint joint diseases of various span bridges,and the common occurrence of joint joint diseases.The development location and development trend,etc.,and the fatigue damage theory,concrete bridge reinforcement theory and hinged plate theory provide relevant basis for follow-up research.Through the fatigue test of the three-beam and two-hinged structure,the whole process of crack development,water seepage,vertical displacement of slabs and beams,dynamic load deflection difference between adjacent slabs and beams,opening and closing and other indicators during the damage process of beam hinge system are investigated and recorded.Exploring the fatigue damage law of plate beams and hinges in the whole life cycle,it is found that the beam stiffness degradation process and the hinge damage process are both in the form of "fast-slow-fast",and a hinge based on the hinge damage coefficient S is proposed.Seam damage evaluation program.Through the fatigue reinforcement test of the bearing vacancy,it is found that the vacancy of the bearing is more prone to squeeze damage,and the effectiveness of the grouting reinforcement is verified.By selecting 2 representative bridges along the line of the Beijing-Shanghai Expressway and Runyang Bridge for on-site inspection,by recording the appearance of hinge joints,the main goal is to test the joint performance of the middle lane corresponding to the joint,and considering the correspondence of overtaking lanes.The hinge joints are tested for performance.Each bridge selects six hinge joints to test the three major indicators of relative displacement,dynamic load deflection,and relative opening and closing.The joint damage coefficient is used as the evaluation plan for real bridge verification to verify its reliability.In order to determine the best time to reinforce the hinge joints,the static load test of the hinged joint system was conducted indoors,and the joint damage coefficient was used as the basis to determine the hinge joints to be strengthened to three states of minor damage,medium damage and severe damage.Comparative analysis The advantages and disadvantages of the glue-filled reinforcement under different damage states of the hinge,it is found that the reinforcement effect of minor damage is not obvious,the reinforcement effect of medium damage is the best,and the performance improvement after severe damage is limited.The research results of this paper can provide references for the joint damage detection and reinforcement of prestressed concrete hollow slab girder bridges,and have certain theoretical research and engineering value. |
