The Analysis And Safety Evaluation Of The Joint Of Steel And Concrete Box Girder Of Chongqing Shibanbo Changjiang Widen Reconstructed Bridge

Composite beam of steel and concrete box girder is the embodiment of the composite materials of steel and concrete, optimization function of the composite beam depends on the combination between steel and concrete beam, and the combination is closely related with shear connectors in connection part of the joint. PBL shear connector is one of the most frequently used connectors in the part of the joint of bridge. At present, the related research of PBL shear connector and the joint of steel and concrete box girder is also less. More research about the mechanical behaviour and finite element model of the PBL shear connector need to do.Based on the joint of steel and concrete box girder of Chongqing Shibanbo Changjiang Widen Reconstructed Bridge, the stress performance of the joint and the PBL shear connectors under static and dynamic load was studied, appling general finite element analysis software. And the local safety state of the joint of steel and concrete box girder was evaluated.The main work of research as follows:â‘ The finite element model of monolithic PBL shear connector in the joint was established with the general finite element analysis software ABAQUS, simulating the action of self-locking of concrete and rebar throughout in the hole of steel plate. Based on the simulating of monocyclic loading test and cyclic loading test, the connection behaviour between PBL shear connector and concrete and the main influence factors was studyed, and the skeleton-frame curve of the PBL shear connector's force-displacement curve was gained, which provided the hysteretic curve to the dynamic finite element analysis of the joint;â‘¡According to the analysis of designing data and the report of the test, paper analyzes the mechanical behaviour of the joint in conditions of typical static loading, the distribution of the joint stress and the relative displacement between PBL shear connector plate and concrete was studied and compared with the result of the test to proved the rationality of the finite element model;â‘¢The whole bridge model was established with SAP2000, and three groups of three directions of the seismics load were chosen, and time history analysis was done to the model to gain the internal force schedules on both ends of the joint. The partial model of the joint was established with ABAQUS, the group of the maximum internal forces time history was applied to the partial model, and the stress distribution and relative displacement of the linkers and the joint of steel and concrete box girder under the action of the seismics load were studyed;â‘£According to the results of static and dynamic finite element analysis of the joint, determine reasonable alarm threshold. The local safety state of the joint of steel and concrete box girder is evaluated according to the general method of bridge health monitoring.