| In order to realize the industrialization of new building,prefabricated building has been actively promoted by the national and government policies,and has played a huge role in many cases,and has made rapid development.The floor not only bears the vertical load,but also plays the role of distributing the horizontal force,so it is very important.At present,the existing prefabricated floor mostly adopts the prefabricated integral floor,some of which retain the shortcomings of cast-in-place structure,so the research and development shows that the effect of the concrete post pouring layer of the prefabricated integral floor is limited,so it is the development direction and rational choice for scholars to develop the fully prefabricated dry floor.At present,the most widely used fully assembled floor is double-t-slab floor,but the existing fully dry floor is mostly double-t-slab floor,which has some problems,such as large span,high structure height,uneven slab bottom and so on,which restrict its application in ordinary civil buildings.The floor is thick,so it is not suitable for civil buildings.Based on this,the research group developed the discretely connected precast RC diaphragm(DCPCD).In this paper,the The building structure with discretely connected precast RC diaphragm(DCPCD)is taken as the research object.The floor of this structure is composed of two parts,namely precast slab and embedded connector.This structure has many advantages,such as excellent structural performance,convenient construction,green energy saving and so on.The test shows that it has good in-plane stiffness and vertical bearing capacity.However,there are some difficulties in seismic design,mainly because the dynamic characteristics and seismic response law of DCPCD building structure are not clear.In order to further reveal the dynamic characteristics and structural response of DCPCD building structure,the shaking table test of fully assembled RC floor structure is carried out,which provides the basis for the future seismic design of the system.The main contents are as follows:(1)Based on the similarity ratio theory and combined with the characteristics of fully fabricated RC floor structure,the design and manufacture of 1/4 scale model of DCPCD building structure are completed.Firstly,according to the focus of this paper,that is,the in-plane stiffness of DCPCD and its influence on the dynamic characteristics and seismic response of DCPCD building structure,the prototype structure of DCPCD is designed;secondly,based on the consistent similarity law,the main structure design is completed,and the DCPCD test scale model design is completed according to the DCPCD in-plane stiffness calculation method verified by experiments.In the model making,the embedded parts are made and processed in strict accordance with the relevant specifications;the components are made in the prefabrication factory,and the shaking table test model assembly and shaking table test are carried out in the laboratory.At the same time,the selection of seismic wave,the arrangement of sensors and the calculation of additional mass are completed.(2)The test phenomena are summarized,and the natural vibration mode,natural frequency,damping ratio and their variation law of the model structure are obtained by sweeping the structure with white noise.The results show that:1.DCPCD test model structure has good seismic performance.2.The order of cracks in DCPCD test model structure is:wall beam joint,beam column joint and slab bottom;after the test loading,the crack forms of each component are:X-shaped network cracks appear in shear wall wall wall,through cracks appear in beam column joint,oblique cracks appear in slab bottom and through cracks appear in x-direction.3.The natural frequency of the structure decreases with the increase of seismic intensity,and the damping ratio increases with the increase of seismic intensity.4.The first vibration mode of the model structure in Y direction is translational motion in Y direction,and the lateral displacement between the lateral force resisting members is not the same.Until the end of the test,the natural vibration mode of the model changes greatly.(3)Based on the test data,the acceleration,displacement,in-plane deformation,internal force distribution,energy dissipation capacity and component strain of the model structure under 7 degree frequent,basic and rare earthquake intensity are systematically analyzed,and the response mechanism of the fully fabricated RC floor structure under the design earthquake intensity is obtained.The results show that:1.The acceleration response and acceleration amplification factor of the middle and side members of the DCPCD test model structure are quite different.2.Under 7 degree frequent,basic and rare earthquake intensity,the floor is relatively intact and is still in the elastic stage.The maximum error between the shear force of lateral force resisting member and the theoretical calculation value of rigid,flexible and semi-rigid floor is about 42%,34%and 12%respectively.3.The story drift angle of DCPCD test model structure can meet the requirements of the code,but there is a large in-plane deformation,and the existing code can not meet the requirements of DCPCD floor rigidity.4.DCPCD test model structure has good energy dissipation capacity.(4)Through the parameter analysis of the full-scale model,the influence law of the stiffness ratio coefficient on the in-plane stiffness of DCPCD building structure is obtained.Based on spring element,the test model structure is simulated by numerical simulation software,and the simulation results are compared with the test data to verify that the spring element can better simulate the response of DCPCD building structure under earthquake action;a full-scale DCPCD high-rise building is established,and the stiffness ratio coefficient of DCPCD building structure is proposed,and the parameters of the numerical simulation model are analyzed by changing the shear wall spacing,and the results are as follows In the structural design of DCPCD,it is suggested that the structural analysis model considering the actual stiffness in the floor plane should be used for the seismic analysis and design of the structure,so as to ensure the reliability of the structure and the rationality of the design.In this paper,through the shaking table test of DCPCD model structure,the dynamic characteristics of DCPCD model structure are understood,including natural frequency,damping ratio,natural mode and its variation law.The dynamic response law of fully assembled RC floor under 7 degree earthquake is analyzed and summarized.By comparing the simulation data with the test data,the stiffness ratio coefficient of DCPCD is proposed,and the seismic response of high-rise building structures with different stiffness ratio coefficients is analyzed.The research results can provide reference for the seismic design of RC floor structures with distributed connections. |
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