Experimental Research On Prefabricated Shear Wall With Composite Alveolar And U-Type Steel Overlap

Compared with the cast-in-place shear wall structure,The structure of prefabricated shear wall can shorten the construction period,reduce cost,improve the quality and has a broad prospect of application.For the structure of prefabricated shear wall,its horizontal and vertical joints of the prefabricated parts tend to form weak sections,and the failures of joints will easily lead to overall damage,which will affect the integrity and seismic performance of the structure.In this paper,a method for connecting the upper and lower layers of prefabricated shear wall by composite alveolar and U-type steel overlap was proposed,and the seismic performance of the prefabricated shear wall was studied.The main works are as follows:(1)The low reversed cyclic loading tests were conducted on three prefabricated concrete shear wall test pieces and a cast-in-place shear wall.The test results showed that both the prefabricated and cast-in-situ test pieces show vertical steel tensile yield and concrete compression failure.The vertical bar of the prefabricated test pieces was connected by U bar in the area of complex tooth space with good stress transfer.The peak bearing capacity of the prefabricated test pieces can be calculated by the standard formula.The ultimate displacement angle of all test pieces is between 1/72 and 1/50,satisfying the limiting value of the displacement angle between elastic-plastic layers of shear wall structure.The hysteretic curve of the prefabricated test piece is rather full,and the ductility coefficient is greater than 5,which indicates that the prefabricated shear wall connected by complex tooth meets the ductility requirements.Prefabricated shear wall with composite alveolar and U-type steel overlap has good bearing capacity,ductility and energy dissipation performance,and it has good seismic behavior.(2)The prefabricated shear wall was numerically simulated by using the finite element software ABAQUS.The results calculated by the finite element model are in good agreement with the experimental results,indicating that this finite element model can reflect the experimental process of each test piece.Based on the finite element model,three parameters including steel shear key,shear span ratio and axial pressure ratio are added to the horizontal seam crossing area for simulation analysis,and the following conclusions are drawn: adding the steel shear key can improve the bearing capacity to a certain extent and reduce the crack degree of bottom construction joint.With the increase of shear span ratio,the bearing capacity and initial stiffness of precast concrete shear wall are gradually reduced.With the increase of axial compression ratio,the bearing capacity and stiffness are improved,and the decline of bearing capacity is more rapid.(3)The shearing force mechanism of the horizontal joint interface of the shear wall is analyzed.The bearing capacity of the normal section,the shear capacity of the inclined section and the shear capacity of the horizontal joint are calculated by referring to the theories and formulas in the relevant normative procedures.The mechanism of the U-type steel overlap of the sheer wall is analyzed.The reliability of the overlap length in this paper is verified by referring to the recommended U-type steel overlap length.