Study On Combined Reinforcement Technology Of Hollow Slab Beam Bridge

In recent years,along with the rapid development of the national economy,our road traffic industry has made new breakthroughs.As a control project of road construction,bridge is still showing new vitality.Among them,hollow slab girder bridge has been widely applied for its convenient construction,prefabrication and convenient transportation.However,after long-term service,the hollow slab beam bridge has been showing various types of diseases,especially the destruction of bridge hinge joints which will cause bridge lateral connection shortage?overall stiffness degradation?single beam bearing and weakened bearing capacity.All phenomenons above will finally affect the operation of the structure.On this basis,to carry out the research of composite reinforcement technology of hollow slab bridge,which in detail is a reinforcement technology of steel crossbeam and vertical prestress,from the aspect of reinforcement member and connection modes.It's supposed to be a highly efficient? reliable and novel method of reinforcement that can not only improve the performance of transverse distribution?enhance the overall stiffness of the structure,but also can enhance the bearing capacity of the structure and improve the stress performance of hinge joints.The technology has also important social significance and scientific significance.The main contents and conclusions of this paper are as follows:(1)The commonly used calculation theory of transverse distribution of hollow slab girder bridge is briefly introduced,and the characteristics and cause analysis of hinged joints are carried out.The requirement and necessity of hollow slab girder bridge reinforcement is clarified.(2)Innovatively put forward the reinforcement method of hollow slab beam bridge,namely the reinforcement method with vertical prestressed and steel beam;according to the principle of equivalent stiffness,elastic plate theory,deflection and load proportional relationship,get a set of transverse load distribution influence line calculation method;according to the characteristics of short rib vertical prestress,proposed vertical prestress anchorage reinforcement design method;according to the reinforcement requirements,put forward the composite reinforcement method of laying steel beam and design process;finally,the construction process ?key points and control technology is introduced.(3)Carry out hollow slab combination reinforcement test,focus on the analysis of the steel beam section size and layout of reinforcement(transverse distribution,overall stiffness)effect,and establishes the quantitative model of the strengthening efficiency of the evaluation index,gain the strengthening efficiency of different sections and different distances,provide a certain basis for the design of combined reinforcement.(4)Established before and after strengthening the solid finite element model by Abaqus software,simulate the contact behavior by vertical prestressed connection,corresponding test conditions,extract the deflection results,obtain the efficiency of finite element calculation results of reinforcement,reinforcement test prediction and curve fitting efficiency curves of different factors obtained are consistent;co MPare and analysis the hinge joint stress before and after reinforcement,the results show that the maximum principal stress of the reinforced joints showed a downward trend,which can improve the effective stress behavior of hinge joint.(5)Based on reinforcement project of Quande bridge,carry out the combination reinforcement design,according to the previous results,the steel beam spacing and cross section form are determined,the vertical tendon and anchor plate are designed and calculationed;Midas finite element model is established before and after the reinforcement,hollow slab bearing capacity analysis calculation is carried out,the results show that the combined reinforcement is able to reduce the effect value under load,which indirectly increase the bearing capacity of the structure;finally,introduces the full bridge construction sequence and construction points under composite reinforcement.