Study On The Effect Of Boundry Element Form On The Seismic Performance Of New Precast SRCCT Shear Walls

Shear walls are used in building structures to withstand vertical loads and horizontal seismic effects,also known as seismic walls.Due to the accelerating pace of urbanization in China and the increasing tension between population and land resources,the number of highrise and super high-rise buildings constructed and the scope of construction are rapidly developing as the main way to solve the conflict.To meet the needs of increasing building heights and to improve the limitations of traditional RC shear wall structures,scholars at home and abroad have proposed steel-concrete combination(SRC)shear walls,which have greater advantages in terms of stiffness,horizontal bearing capacity and construction process compared with traditional shear walls,and are more widely used in various building structures with increasing bearing capacity and flexural stiffness.Group proposes a new precast steel-concrete composite tube(SRCCT)shear wall.Compared with the double steel plate shear wall,the outer concrete of the tube unique to the new precast SRCCT shear wall structure can produce effective restraint on the double steel plate and inhibit the out-of-plane buckling of the steel plate,while effectively improving the problems of high protection cost and poor durability caused by the exposed steel plate.However,in the study of seismic performance of new precast SRCCT shear walls,the influence law of the boundry element form on the seismic performance of SRCCT shear walls and the design method of SRCCT shear walls are not yet perfect.Therefore,it is of great theoretical significance and application value to carry out the investigation of the influence law of different boundry element forms on the seismic performance of new precast SRCCT shear walls and to improve the design method of SRCCT shear walls.In this paper,the seismic performance of new precast SRCCT shear walls with different boundry element forms is analyzed through experimental research,theoretical analysis and numerical simulation,and the main research contents are as follows:(1)Low-period reciprocating load tests were conducted on the new precast SRCCT shear walls with different boundry element forms to reveal the force mechanism of the new precast SRCCT shear walls under the reciprocating load.Based on the hysteresis curve,horizontal bearing capacity,displacement ductility,stiffness degradation and energy dissipation capacity of the specimen,the force mechanism and seismic performance of the specimen under the reciprocating horizontal load are analyzed,and the study shows that the SRCCT shear wall with different boundry element forms has better seismic performance,and under the same axial pressure ratio and the same form of boundry element conditions,increasing the boundry element thickness and flange length of the specimen at the same time can significantly improve Under the same axial pressure condition,the effect of changing the boundry element specification on the horizontal bearing capacity of SRCCT shear wall is greater than that of changing the boundry element form of SRCCT shear wall,and at the same time,changing the boundry element strength and flange width can effectively improve the horizontal bearing capacity of SRCCT shear wall.(2)Numerical analysis of the new percast SRCCT shear wall was carried out to investigate the influence law of different design parameters on the force performance of SRCCT shear wall.The model is loaded with monotonic pushover,and the simulated positive loading skeleton curve and the specimen force state are compared with the test to verify the reliability of the modeling method,and further analyze the force state analysis of the SRCCT shear wall.It is recommended that the axial compression ratio should not be greater than 0.5;the shear-to-span ratio should be 1.0-2.0;the diameter of the spigottensioning bar should be 6mm-12mm;and the distance-to-thickness ratio should be 30-50.(3)Based on the basic principles of material mechanics and superposition method,the horizontal bearing capacity and stiffness calculation method of the new precast SRCCT shear wall was established,and the correctness of the theoretical calculation method of the SRCCT shear wall was verified through tests.Based on the damage pattern of the specimen and the analysis of the finite element results,the calculation formula of the positive section bearing capacity of SRCCT shear wall is derived based on the assumption of the basic principles of material mechanics,considering the restraint effect of the steel combination tube on the concrete inside the tube,and the calculation formula of the initial stiffness of the shear wall is derived based on the superposition method,and the test value is compared with the theoretical value to verify the reliability of the calculation method and provide the theory for the application of SRCCT engineering design.The experimental values are compared with the theoretical values to verify the reliability of the calculation method and to provide theoretical reference for SRCCT engineering application.