Seismic Performance Analysis Of Precast RC Frame With Different Joint Connection

Nowadays,the researches on the precast reinforced concrete frame structures focus on the joint and the plane frame,while lacking the researches on the precast reinforced concrete frame structures with floor.Considering that the force of space frame structure of precast reinforced concrete is relatively complex,which may behave different form and seismic performance from plane frame,it is necessary to study the space frame structure of precast reinforced concrete and tell the differences between the seismic performance and common RC frame.The finite element software was used to analyze the unidirectional and reciprocating loading of precast space frame structures of the partial steel connection,the hidden corbel connection and the prestressed connection.Meanwhile,the parameter analysis was also carried out.The main contents and conclusions are as follows:(1)The unidirectional loading of the precast and partial steel space frame was analyzed.The results show that the bearing capacity of the precast and partial steel space frame is higher than the ordinary RC frame.The plastic hinge mainly comes into being at the end of the steel,which effectively protects the core areas and the steel joints.(2)The reciprocating loading of the precast and partial steel space frame and the RC frame was carried out.The results show that the plastic hinge of the precast and partial steel space frame is less developed than the ordinary RC frame.It has good retentivity of bearing capacity and stiffness and good ductility.Due to the end of the steel column is easy to produce plastic hinge,it is recommended to pay attention to the stiffness mutation in the design process to prevent "column hinge damage".The parametric analysis of precast and partial steel space frame was carried out.The result shows that the axial compression ratio has a great influence on the damage mechanism of the frame.It is suggested that the axial compression ratio should be controlled within 0.4.(3)The unidirectional loading of the four precast hidden corbel frame was carried out.The results show that welding steel plate can improve the bearing capacity of the hidden corbel,prevent damages from focusing on the joints and improve the overall performance of the frame.(4)The reciprocating loading analysis of three kinds of precast hidden corbel frame and ordinary RC frame was carried out.The results show that the bearing capacity of the hidden corbel frame of the welded steel plate decreased slower than that of the ordinary RC frame,and it has good ductility.The plastic hinge is moved to the end of the notched beam.Welding steel plate in the joint of beam profile can reduce the damage of corbel joint.(5)Through the unidirectional loading analysis of the prestressed space frame and the empty frame,it shows that the presence of the floor makes the corbel joint bear greater stress.It is recommended that in the design of the corbel,the impact of the floor should be considered.Parametric analysis of prestressed space frames shows that the axial compression ratio and welded steel plate have a great impact on the bearing capacity.(6)Under reciprocating loading,the comparative analysis between the equal reinforcement ratio of the RC frame and three kinds of prestressed space frames is carried out.The results show that the prestressed space frame has good ductility whenever it’s with or without welded steel plate.Welded steel plate can improve the bearing capacity of the frame and the force behavior of the notched beam,and prevent the prestressed tendon from being pulled off.