Total Bolt Connection Prefabricated Concrete Structure Joints And Carrying Capacity Research

Vigorously promoting prefabricated construction conforms with the development strategy of national housing industrialization.Total Bolt Connection Prefabricated Concrete Structure(BPC)is on-site full-dry-work assembly structure.The production of prefabricated components is standardized in factory.The assembly is very easy and the construction period is very short.The modular advantages fit BIM technology and it has high value of scientific research and engineering application.There are a lot of horizontal and lateral seams in BPC structure.So the construction method of bolting at seams has a great influence on the mechanical behavior and engineering applications of the structural system.This paper takes the bolt connection joints of BPC structure as the main research object,using the test and finite element analysis to explore a more reasonable joint construction method to improve the mechanical behavior of the BPC structure.Main contents are as follows:(1)The results of low-cycle reciprocating loading test of single-layer shear wall: The damage of the assembled shear wall of BPC is caused by the destruction of the concrete at the connection of the wall panel.When the wall is broken,the bottom bolts are mainly subjected to axial tension.And the lateral bolts are mainly subject to shear force because of the dislocation of the adjacent wall panels.(2)Refined model of double-layer shear wall of BPC structure is built using ABAQUS Finite Element Software,calculation results proves that the damage process of the lower left corner and the final failure characteristics of the wall consistent with the test phenomenon of the one-way loading in low-cycle reciprocating loading test of single-layer shear wall.The finite element calculation results of axial tension of bolts at typical joints are very close to the calculation results referring to relevant code.The most unfavorable-position bolts of wall panel-bottom pad connection joint and wall panel-middle pad connection joint are mainly subjected to axial tension.The most unfavorable-position bolts of the lateral connection joints of wall panels are mainly subject to shear force.(3)Considering a variety of factors,Using ABAQUS Finite Element Software to analysis the connection joints of BPC structural wall,Meaningful conclusions are as follows: for the bottom connection joints of prefabricated wall panels it is recommended to use steel plates of slightly larger size,C50 strength grade concrete and bolts with moderate diameter and densify the wire mesh at the connection joints to improve the vertical stiffness and vertical bearing capacity of the connected joints;for the lateral connection joints of prefabricated wall panels,it is recommended not to add steel plate,choose C50 strength grade concrete and densify the wire mesh at the connection joints to improve the mechanical performance of the lateral connection of the wall panels.The above research results provide experimental and theoretical basis for the improvement of BPC structure connection joints construction method as well as references for further engineering applications,targeted research and the research on other modular concrete structures with dry connections.