| As the urban usable land area is declining with the rapid growth of China’s urbanization and the development and transformation of the urban industrial structure,more and more cities in China have adopted steel-concrete composite structures instead of ordinary reinforced concrete.Structure of super high-rise building.At present,there are many researches on the seismic performance of composite structural column members and single composite structures,but as RC frame-core tube lateral research,the comprehensive comparison of steel tube concrete structures,steel reinforced concrete composite structures,and ordinary reinforced concrete structures is relatively lacking.Therefore,it is of important engineering significance and theoretical research value to explore the influence of the frame column of the composite structure on the lateral performance of the RC frame-core tube.This paper first analyzes the overall seismic performance of an actual project RC frame-core tube structure,uses PKPM and Midas software to calculate the seismic structure of the project under frequent earthquakes and fortified earthquakes,and passes PKPM software under rare earthquakes.The PUSHOVER program in,performs static pushover analysis to verify the rationality of its structural system.Based on the consideration of improving the working performance of the structure and improving the use of the building space,to maintain the same axial compression ratio of the frame columns,the ordinary reinforced concrete outer frame columns of the RC frame-core tube structure were replaced with I-shaped steel concrete columns,steel tube concrete columns,For steel reinforced concrete columns,the non-linear finite element program based on the theory of three-dimensional solid degenerate virtual laminated element is used to further carry out the research on the lateral performance of the RC frame-core tube.In view of the fact that there are many and mature researches on the mechanical performance of concrete-filled steel tube columns and steel-steel concrete columns,while the research on concrete-filled square steel tube columns is relatively small,we will first take the concrete-filled steel tube columns as an example to make a separate impact on their lateral performance.Analysis,that is,consider the nonlinear analysis of the lateral performance of the concrete-filled square steel tube column model with different steel content,inner concrete strength,steel tube strength,axial compression ratio,and slenderness ratio,and draw load displacement curve and stiffness degradation curve.Summarized the influence of these factors on the horizontal bearing capacity and ductility of the structure,and provided a reference for the next step in the study of the lateral performance of the RC frame-core tube considering the composite structural column.On the basis of the above research,for the four-story structure at the bottom of the actual engineering structure,the axial compression ratio of the frame column is kept consistent,according to the four situations of ordinary reinforced concrete column,I-shaped steel concrete column,square steel tube concrete column,and round steel tube concrete column.Respectively establish refined finite element analysis models that consider the space collaboration of beams,slabs,columns,walls,and space walls to explore the influence of different outer frame column structures on the lateral performance of the overall structure under horizontal seismic forces: compare and analyze the shear force of each model on each floor The share ratio and stiffness degradation and the comparison of the stress of the steel bars at the beam ends at the column nodes of the four groups of models,etc.,through the analysis results,summarized the law of the influence of different outer frame columns on the lateral performance of the structure.The above research results can provide reference and reference for the seismic design theory of RC frame core tube structure containing composite structural columns. |
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