The Influence Of Slanting Column On The Seismic Performance Of RC Frame Structure

This paper focuses on the influence of inclined column on the seismic performance of RC frame structure,which is a common structural form of multi-storey buildings.It focuses on the research and Discussion on the influence of inclined column layout and inclination on the control index,deformation form,stress mode,bending mechanism and failure mode of RC frame structure under rare earthquake.The main research work and achievements are as follows:(1)Three frame structure models with inclined columns arranged in short span,long span and straight column frame are established.The influence of inclined column location on seismic performance of frame structure is discussed.The results are verified by elastic time history analysis method.It is concluded that the arrangement of external inclined columns in long-span frame structure is unfavorable to seismic performance of frame structure.(2)Five frame models are established by changing the inclination angles of inclined columns in the long span,and the elastic analysis of them under frequent earthquakes is carried out.The influence of the inclination angle of inclined columns on the seismic performance of frame structures is discussed,and the results are verified by elastic time history analysis method.(3)Based on the calculation results of frequent earthquakes,the frame structure model considering floor and reinforcement is established,and the reinforcement of each model is consistent.The static elasto-plastic analysis of the frame model with three inclined column inclination angles under rare earthquake action is carried out.From the calculation results under two load distribution conditions of inverted triangle and uniform distribution,it can be seen that the most unfavorable direction of pushing force is along the outward inclined direction of inclined column,and compared with the uniform distribution,the inverted three angle distribution has a greater impact on the deformation and energy dissipation capacity of the frame structure.(4)On the basis of the above research,based on the inverted triangle distribution,the static elastic-plastic analysis of five frame models with different inclination angles of inclined columns under rare earthquake is carried out,and the influence of inclination angle change on the seismic performance of frame structure under rare earthquake is discussed.Under rare earthquake,with the increase of inclination angle of inclined column,the stiffness of frame structure is lower,the seismic performance is worse,and the weak floor of structure is more prominent.According to the distribution and development degree of plastic hinge of beam and column,the increase of inclination angle of inclined column accelerates the generation and development of plastic hinge of frame structure,and even changes the yield mechanism of frame structure.When the inclination angle of inclined column is less than 15 °,the frame structure can still be in the traditional beam hinge type yield mechanism,which conforms to the seismic concept of "strong column and weak beam".When the inclination angle of inclined column is greater than 15 °,the plastic deformation of the frame structure can not be fully unfolded,and the yield mechanism of the frame structure may change to the column hinge type and brittle failure will occur.(5)In view of the weak floor caused by the large inclination angle of inclined column,two improvement schemes are put forward.By using the methods of elastic analysis,static elastic-plastic analysis and dynamic elastic-plastic analysis,the seismic performance improvement effect of the improved frame structure model is comprehensively compared and verified.