Study On The Construction Method And Mechanical Properties Of New Type Composite Frame Bridge Joint

Steel reinforced concrete(SRC)structure has become one of the preferred structures in many buildings.Although both at home and abroad on mechanical performance of coagulation type reinforced concrete structure is studied a lot,but some research on the performance of joints of steel reinforced concrete structure is still exist many problems,needs to be further discussed.For the SRC framework,the joint is the transmission hub in the structural system,and the shear failure of the joint is one of the important reasons leading to the instability and collapse of the structure.Therefore,it is very important to ensure the safety and reliability of the joint.In this paper,the detailed structure and mechanical behavior of the new SRC frame bridge joint are studied by numerical simulation and theoretical analysis,and the test is verified.According to the structural characteristics of joints,the stress of beam column joints mechanism which is based on the research results,the shear calculation process is deduced and numerically the preliminary understanding of the shear principle of joints;the joints were then analyzed by finite element software,according to the stress and strain distribution on mechanical properties of type steel concrete joints are discussed;finally,the research results can be applied to practical engineering.The main contents are as follows:1,According to the core area theory of joints and the relevant codes,the mechanical mechanism of SRC beam column joints is studied,and the theoretical formula of the shear resistance of the joints of the frame bridges is obtained.2.The joint model is established by the finite element software.The influence of the angle of the haunch,the change of the dimension of the haunch angle and the diameter of the diagonal rib on the mechanical properties of the structure are analyzed.Find the axillary angle for artanl/3 are the best haunched angle,which is consistent with the conclusion of existing reinforced concrete structure,haunch size should be based on the actual span frame bridge to set in the steel reinforced concrete joints,changes in joint diameter of diagonal reinforcement bearing capacity influence is very small,can be neglected by changing the type;the thickness of steel webs,concrete strength and other parameters to analyze the effect of shear bearing capacity of anti joint,that concrete and steel stress and strain distribution and the ultimate load.3,Through the analysis of the finite element considering the bond slip and not considering the bond slip effect on the bearing capacity of the structure,analysis of the different concrete strength,steel,stirrup ratio condition,influence of bond slip on bearing capacity of steel reinforced concrete structure.The results show that increasing the amount of steel and concrete strength ranging from increase of mechanical properties of the structure,is different with the increase of steel ratio,the bond slip between concrete and steel is also more obvious;and improve the strength of concrete,the bond slip effect of joint bearing capacity has become more and more small;in addition,the stirrup rate has little effect on the carrying capacity of the structure,but can guarantee a good bond slip between the core zone of the joint of steel and concrete.It is necessary to select the appropriate stirrup ratio.4,In the research content from the project,the research results are applied to engineering principle,optimized design of frame bridge engineering joint,and the steel reinforced concrete frame bridge is analyzed through the calculation of steel reinforced concrete frame bridge structure analysis can be drawn:under normal load,the components of frame bridge are to meet the requirements of bearing capacity.And from the economic benefits and convenience of construction and reinforced concrete made a comparative analysis,that this new type of composite frame bridge has great advantages.