| The reasonable evaluation of the anti-seismic performance and anti-collapse ability of a structure is the premise and foundation for improving the anti-collapse ability and optimizing the anti-seismic design of this type of structure.CFT frame sturcture-RC shear wall structure as a new structural system,there is not enough research on the seismic performance of the structure system at home and abroad.In order to facilitate the application of this kind of structure system in engineering practice,it is necessary to carry out the quantitative analysis of the collapse resistance of this kind of structure.In this paper,the seismic performance and collapse resistance of CFT frame structure-RC shear wall structure with different seismic fortification levels of 7 degree(0.10g)and 8degree(0.20g)seismic fortification are studied.Firstly in this paper,the elastic-plastic analysis model of CFT frame-RC shear wall structure is proposed and verified by experiments.According to the difference of shear sharing ratio and bearing capacity of frame,six typical CFT frame structure-RC shear wall structural models are designed,and their spatial model and the equivalent plane analysis model are established.Then,the static elastoplastic analysis method and dynamic elastoplastic analysis method are used to study the seismic mechanism and performance of the structures with different parameters.After that,the IDA method is used to analyze the seismic vulnerability and anti collapse ability of the structure system,and the characteristics and rules of IDA curve,seismic vulnerability matrix and anti collapse safety reserve coefficient of different calculation examples are given.Finally,based on the above analysis results,some suggestions are put forward for the design of CFT frame structure-RC shear wall structure.The main innovations of this study include: The influence of different shear sharing ratio and frame bearing capacity on the seismic mechanism and collapse resistance of CFT frame-RC shear wall structure is revealed.An elastic-plastic analysis model of CFT frame-RC shear wall structure is put forward,and the equivalent method of transforming spatial model into plane model is given.The collapse resistance and vulnerability of CFT frame-RC shear wall structure are revealed by IDA method.Based on the analysis results of this paper,the main conclusions are as follows:(1)Based on the static pushover analysis of CFT frame-RC shear wall structure,the structural capacity curve and the development of component plastic distribution are analyzed.It is found that the CFT frame RC shear wall structure system with high initial shear and relatively large frame stiffness has the highest initial stiffness and peak bearing capacity.The development sequence of the plastic hinge of CFT frame-RC shear wall structure that meets the requirements of the code in China meets the requirements of the seismic fortification defense line and the design requirements of "strong column and weak beam",has good seismic performance.(2)Through the dynamic elastic-plastic analysis of CFT frame-RC shear wall structure,the development of the structure vertex displacement,the elastic-plastic inter story displacement angle and the component plastic distribution are analyzed.It is found that the vertex displacement indexes of the three examples with the same seismic fortification level are very close,and the difference of the average maximum vertex displacement values is very small.Under the 7 degree(0.10g)seismic fortification level,the average value curve distribution mode of the three calculation cases is close to each other;under the 8 degree(0.20g)seismic fortification level,the average value curve of the three calculation cases has certain difference,the initial shear force of the frame is high,and the deformation performance of the CFT frame-RC shear wall structure with relatively large frame stiffness is higher.The ductility of the three examples is close under the 7 degree(0.10g)seismic fortification level,and the ductility of the CFT frame RC shear wall structure system is slightly lower under the 8 degree(0.20g)seismic fortification level after shear amplitude modulation.(3)Through the IDA analysis and seismic vulnerability analysis of CFT frame-RC shear wall structure,it is found that: three kinds of calculation examples can meet the seismic fortification requirements of "three levels" in probability sense;the CFT frame-RC shear wall structure with high initial shear and relatively large frame stiffness has the highest anti collapse safety coefficient and the strongest anti collapse ability.(4)Based on the research results of this paper,the following design suggestions are put forward for the engineering design of CFT frame-RC shear wall structure system:The lateral stiffness of CFT frame should be increased;The shear wall design at the bottom reinforcement should be strengthened in the high intensity area;The weak coupling beam design should be adopted in the coupling beam;The requirements for the bearing capacity limit of CFT column can be reduced in the low and medium intensity area. |
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