Research On Seismic Performance Of Slab-wall Structure Incorporating Steel Tube-confined Concrete Shear Wall

Currently the trend of construction technology in China is construction industrialization.The use of reinforced concrete(RC)slab-wall structures has the advantages of increasing floor clear height,improving construction efficiency and suitability for industrial production.But the ordinary RC slab-wal structure has poor ductility.The slab is damaged under rare earthquake so that the strutcture relies on each single shear wall to resist earthquake.It is very important that the shear wall has good ductility.The steel tube-confined concrete shear wall(STCCSW)can greatly improve the ductility of concrete and increase its axial bearing capacity.Therefore,based on the research of STCCSW,our research group developed an innovative "slab-wall structure incorporating STCCSW" to improve the ductility of the ordinary RC slab-wall structure.In this thesis,the seismic performance of this new structure is intensively studied.The scope and conclusion of this thesis are as followed:(1)A 1/8-scaled wall-slab structure strengthened with steel tube-confined concrete is tested on a shaking table to study the dynamic characteristics,failure and seismic performance of this new structure.The test results show that the wall-slab structure strengthened with steel tube-confined concrete can meet the requirements of code for seismic design of buildings when the axial compression ratio reaches 0.5.(2)The numerical analysis model of the shaking table test prototype is established by using equivalent frame method in Perform-3D software.The dynamic easto-plastic analysis of the prototype is carried out and the results are compared with the test.The analysis results verify the feasibility of the numerical analysisi model of the slab-wall structure incorporating STCCSW.(3)12 numerical models are established by changing the thickness of the shear wall,the thickness of the slab and the reinforcement ratio of the slab,and the push-over analysis is carried out in Perform-3D software.The analysis results shows that the ductility factor of the slab-wall structure incorporating STCCSW is related to the thickness of shear wall,but it is independent of the thickness of slab.The thicker of STCCSW,the better the ductility of the structure.Thickened slabs have a great influence on the stiffness of the structure,but have little effect on the ductility.It depends on the STCCSW itself.In the case of the same thickness of slab and shear wall,the larger the reinforcement ratio of slab,the slower the structural stiffness degradation,and the better the ductility of the structure.(4)8 Perform-3D analysis models of 4 different heights of the slab-wall structure incorporating STCCSW and the ordinary RC slab-wall structure are established.10 ground motions are selected for each model.320 times of bidirectional seismic dynamic elasto-plastic time history analysis are carried out.The analysis results shows that in the elastic stage,the structural stiffness and mechanical property of the slab-wall structure incorporating STCCSW and the ordinary RC slab-wall structure are close under the circumstance of the same story height,story numbers,layout,thickness,length and the axial compression ratio of shear wall.When entering the plastic stage,the stiffness degradation of the slab-wall structure incorporating STCCSW is slower than the ordinary RC slab-wall structure,and the damage of the components is slighter.With the increase of the height of the structure,the weakness of the ordinary RC slab-wall structure are more obvious,while the slab-wall structure incorporating STCCSW can maintain good seismic performance and ductility.Therefore,the new structure can cover the shortage of the old one.In the proposed specification,the maximum height of the slab-wall structure in 7 degree area is 70 m,which can be moderately relaxed when using the slab-wall structure incorporating STCCSW.