Study On Seismic Performance Of Fully Precast Frame-Shear Wall Structure

In recent years,green buildings have vigorously developed to promote energy-saving emission reduction of construction industry in China,construction industrialization is the main direction of China's future housing construction.The precast frame-shear wall structure,as an important structural system of residential industrialization,is a good combination of the advantages of frame structure and shear wall structure with broad prospects for development.It can not only flexibly arrange and provide large space,but also increase the height of structure.However,how to disassemble the frame-shear wall structure and achieve the connection between prefabricated elements is the key measures to ensure that the structure has good seismic performance.The key to connection between the prefabricated elements is in two aspects,one is the combination of prefabricated components of the way,the second is the prefabricated components of the connection.This paper systematically combs the connection form and characteristics of the existing precast structure.On this basis,a feasible precast frame-shear wall structure has been proposed.The specific implementation is as follows:In order to improve the safety of the column connection,the frame column is prefabricated with the node and is split at 1/2 of the column,and the reinforced bar is connected with the grouting sleeve.The beam in frame is in the form of a composite beam,which is spliced at the end of the beam and is connected by the post-cast strip;The reinforced bar is connected with the grouting sleeve.Shear walls are wholely prefabricated and are connected using the restraint pulp anchor lap vertically;The reinforced bars in side column or dark column selection are connected in grouting sleeve connection form.The connection between the frame and the shear wall is similar to that of the beam and column joints,and the shear wall side pillar acts as a column in the frame structure and is connected to the prefabricated composite beam.According to the method of numerical simulation,the mechanical properties of the integral shear wall structure under the horizontal load are studied by numerical simulation.The factors influencing the mechanical properties of the prefabricated shear wall are analyzed.The results show that the load-bearing capacity and deformation capacity of the shear wall are slightly lower than those of the cast-in-place shear wall,and the decreasing magnitude is within 10%.When the aspect ratio reaches 2,the failure mode of the component are typical bending failure,which can meet the requirements of the standard design.Under the condition of bending failure,,the bending capacity of the shear wall increases while the ductility decreases with the increase of the axial compression ratio.In a certain range,the ductility and bearing capacity of the shear wall are increasing with the increase of the reinforcement ratio.Then,the low-cyclic loading test of the two frame-shear wall structures was carried out,and the crack development and failure modes of the specimen were analyzed.The bearing capacity,ductility and energy dissipation performance of the frame-shear wall were analyzed.And then,the failure mechanism of the structural system and the reliability of the assembly scheme were analyzed.The results show that the overall hysteresis performance,stiffness degradation,ductility and energy consumption of the precast frame-shear wall structure are similar to those of the cast-in-place structure,and the the difference of bearing capacity is within 5%.The failure mechanism of the two members is similar:After the shear wall is yielded,the joint beam appears plastic hinge;Finally,the beam and column of the frame are damaged.There is no damage to the assembly joints,indicating that the proposed assembly is reliable.Then,the mechanical properties of the frame-shear wall structure are numerically simulated.The mechanical properties and failure modes of the fully assembled frame-shear wall structure are analyzed.The key parameters of the structural force performance are analyzed.The results show that the finite element results are in good agreement with the experimental results,and the interface model can simulate the mechanical properties of the assembly.The peak load only increases by 3.2%when the strength of the bed layer increases from C35 to C50;when the axial pressure ratio of column/shear wall increases from 0.15/0.12 to 0.5/0.4,the peak load increases by 19.5%and the limit displacement decreases by 10.3%;When the thickness of the seat plate reaches 20mm with a high strength grade of concrete,the structure can meet the design requirements.