Research On The Wet Joints Structure And Force Transfer Of Prefabricated Deck In Steel And Concrete Composite Bridge

With the development of bridge construction,the construction of prefabricated bridge based on assemblage will be an effective way to solve the problem that the construction quality is difficult to guarantee and the construction speed is slow.The steel and concrete composite bridge is a kind of high performance bridge structure which is easy to realize fast assembly,which satisfies to the national bridge construction requirements of prefabricated,standardization and industrialization.To achieve the goal of industrial construction of steel-concrete composite bridge,it is necessary to solve the problem of connection between the modules,among which the connection between the bridge decks is one of the key technology.In order to transfer shear and moment better,it is common to use wet joints in the prefabricated bridge deck.But there are cracking,leaking and other problems in wet joints,affecting the performance of the bridge.At home and abroad,experts and scholars have made some research on the wet joints of prefabricated bridge deck,and some new forms of wet joints are put forward,but there are some limitations in the existing research,and the force transfer of wet joints is not clarified.Based on the existing research on the wet joints of concrete prefabricated bridge deck,this paper studies the mechanical performance of two kinds of wet joints of loop bar joints and headed bar joints and analyzes the force transfer of wet joints according to the stress of whole process of specimen.The main contents and conclusions of this paper are as follows:(1)A systematic introduction and analysis on the wet joints of concrete prefabricated bridge deck.Based on the domestic and international experimental study,the flexural strength of the wet joints was calculated and compared with the experiment.The results show that the theoretical value and test value of about 10% difference.(2)Based on the foreign experimental study,the finite element model is checked.By comparing the ultimate load and the vertical deflection of the specimen,it is found that the finite element model can accurately simulate the wet joints.Through the study of the mechanical properties of the longitudinal wet joints,it is found that the strength of the concrete,the lap length and the reinforcement ratio all have some influence on the flexural capacity and rigidity of the wet joints.With the increase of the reinforcement ratio,the ultimate load and rigidity of the joints increase significantly.The effect of the lap length on the stiffness of the wet joints is not obvious.(3)In order to simulate the force transfer of the wet joints better,the two types of transverse wet joints were analyzed.From the test results,the force of loop bar joints and headed bar joints are similar.The main reinforcement is the rod and the compression concrete column with the opposite end of the rebar is the pressure and bar end section is the node of the model.