Research On Seismic Performance Of Precast Prestressed Concrete Composite Shear Wall With High Shear Span Ratio

At present,my country’s economy is in a stage of rapid development and is under construction of modern cities.The prefabricated building has received strong support from the country,and the advantages of the prefabricated structure are also reflected at some levels.At present,the domestic prefabricated laminated shear wall is a building structure system imported from Germany suitable for China’s situation.It is widely used because of its standardized factory production and on-site construction procedures,but its self-importance,transportation difficulties,and inconvenient lifting Other shortcomings also restrict the development of prefabricated shear walls.Based on the present situation,this research proposes a new type of precast concrete composite shear wall,namely the precast prestressed reinforced concrete truss composite shear wall,the shear wall with steel truss is first precast block prestressed concrete wall panel,and then the field assembly,into the cavity between the concrete to form a whole.For the representative "one" type shear wall in the actual project.In this paper,the construction method of prefabricated prestressed concrete composite shear wall was used to make two full-size specimens,and the cast-in-place shear wall specimens were made for comparison.The seismic performance of shear walls was studied through low cyclic load tests,and the lateral displacement,horizontal load,distribution and development of cracks,and reinforcement strain of shear walls were recorded in detail.The yield mechanism and failure type of prefabricated composite shear wall are analyzed and compared with cast-in-place shear wall to investigate the performance of prefabricated prestressed concrete composite shear wall under earthquake action.In this paper,the influences of axial compression ratio and prestress on the composite shear wall performance of precast prestressed concrete are considered.The test results show that the failure modes of precast shear walls and cast-in-place shear walls are basically the same,both of which belong to bending-shear failure.Precast prestressed concrete composite shear wall in the applied prestressing can effectively delay the time of inclined cracks appear,and precast prestressed concrete composite shear wall relatively full hysteretic curve,through to the precast prestressed concrete composite shear wall and cast-in-place shear wall energy dissipation coefficient and the equivalent viscous damping coefficient is compared,found the precast prestressed concrete composite shear wall is superior to the energy dissipation of cast-in-situ specimen.The ductility of the composite shear wall of precast prestressed concrete is slightly worse than that of the cast-in-place shear wall,which is related to the stress outside the plane in the later stage of the test.Generally speaking,the seismic performance of precast prestressed concrete composite shear wall is close to that of cast-in-place shear wall.The finite element software ABAQUS was used to establish the composite shear wall model of precast prestressed concrete with high shear span ratio to simulate the stress distribution of the shear wall under the action of nappa load,and the simulation results were compared with the test results,which proved that the simulation analysis results had higher reliability.At the same time,the simulated load-displacement curves under different coaxial pressure ratios are compared and analyzed,and it is proved that excessive axial pressure ratio reduces the ductility of shear wall,so the value of axial pressure ratio of shear wall should not be too large.