基于有限元的预应力混凝土空心板梁抗剪加固性能研究OA

The concrete hollow slab beam used for bridges constructed earlier is thinner than those for the current bridges.Thus,during vehicle operation,thses beams are prone to shear cracks due to insufficient shear bearing capacity.So,reinforcement measures need to be taken to improve the bearing capacity of the bridge.In order to study the shear bearing performance of prestressed concrete hollow slab beams,this pa-per takes a highway bridge built by using hollow slab beam as the research object and proposes three methods with vertical prestressed reinforcement,combined stiffness hoop,and diagonal prestressed rein-forcement respectively.Through finite element simulation calculation,the principal strain of the concrete in the beam body,hoop stress,longitudinal reinforcement stress,as well as the stress of reinforcement bars and members under different reinforcement methods are analyzed.The results show that under different re-inforcement methods for concrete hollow slab beam bridges,compared with the other two reinforcement methods,the method with combined stiffness hoop reinforcement can maximize the shear resistance and crack resistance of the inclined section of the components.At the initial stage of external load loading,un-der different reinforcement methods,the stress values received by each reinforcement bar are similar.At the end of loading,compared with other two reinforcement methods,the combined stiffness hoop reinforce-ment receives the smallest stress.A comparative analysis is conducted on three reinforcement methods for concrete hollow slab beam bridges,and it is found that the maximum shear bearing capacity of the slab beam is 775.05 MPa with combined stiffness hoop reinforcement.