Study On Correlation Between Floor Seismic Shear Coefficient And Seismic Performance Of Framed-tube Structure

Due to the ever-increasing height of the building structure,the designer encountered more and more problems in the process of adjusting the seismic shear coefficient of the floor to meet the specification requirements,and the current code does not give the value of the minimum seismic shear coefficient of the floor.The theoretical basis has led some designers to question the rationality and applicability of the current regulations on the seismic shear coefficient of floors.In addition,there are still some shortcomings in the research on the minimum seismic shear coefficient of the floor:(1)The case has not been systematically designed,and the number of examples is small,mainly through a structure that meets the specification limits and does not meet the specification requirements.A systematic and in-depth study is made on the minimum seismic shear coefficient of the floor.(2)Based on the elastoplastic analysis,the seismic performance of the structure is qualitatively evaluated through lateral deformation and component stress.The evaluation index is too single.Therefore,the Park-Ang two-parameter failure criterion is introduced to systematically study the seismic performance of the seismic shear coefficient structures of different floors,and determine the corresponding seismic shear coefficient of the floor when the seismic performance of the structure is optimal,which is the quantitative analysis of the minimum seismic shear coefficient of the floor.The value provides the basis.In this paper,five 33-layer frame-tube structure examples are designed.Under the class II site,the relationship between structural internal force,lateral deformation,plastic energy dissipation,member stress and floor seismic shear coefficient is studied.Based on the above analysis results,calculation is performed.The overall damage index of the structure is analyzed and its relationship with the seismic shear coefficient of the floor is considered.Considering the influence of the site type,the research in the class II site will be extended to Class I-IV,and the lateral deformation,overall damage index and floor seismic shear coefficient of the structure will be studied.relationship.Based on this,the main conclusions of this paper are as follows:(1)In the Class II site,under the rare earthquake,when the seismic shear coefficient of the floor is in the range of 1.47%-1.80%,the lateral deformation gradually decreases,although the magnitude and speed of the decrease are reduced,but the degree of deformation is still limited.It is more objective.It is suggested that under the actual circumstances,the stiffness can be appropriately increased,the seismic shear coefficient of the floor can be increased,and the lateral deformation of the structure can be reduced.When the seismic shear coefficient of the floor is 1.71%,the structural plastic energy consumption is the smallest,and the structure enters.The lowest degree of nonlinearity.(2)In the Class II site,under the rare earthquake,when the floor seismic shear coefficient is 1.55%,the overall structural damage index is the lowest,the structural damage degree is the lightest,and the structural shear factor is 1.55%-1.80%.The slope of the damage curve is not obvious.Especially when the seismic shear coefficient of the floor is 1.60%,the overall damage index is very close to the lowest value.Therefore,under the category II site,the limit specified by the specification can be considered reasonable.When the land type changes,special research is needed on the site where the structure is located.(3)The site category has the characteristics of the seismic shear coefficient of the enlarged structure floor,and the amplification effect of the soft soil site is more obvious;in the I and II types of sites,the minimum seismic shear coefficient limit of the floor can improve the seismic performance of the structure and ensure the structural safety.For Class III and Class IV sites,it is necessary to appropriately increase the minimum seismic shear coefficient limit of the floor.Therefore,it is recommended that the current current regulations need to consider the impact of the site category.