The Optimization On The Section Of Beam-column Of Reinforced Concrete Frame Structure

The upper and lower reinforcement of beams need to be determined by the sectionmoment in the process of design for frame structure. If the differences of the beam-endmoment and the mid-span moment are too large, the concrete material of the smaller momentsection can not be fully utilized, which can lead to material waste. In order to make full use ofthe materials and give full play to the mechanical properties of the materials, if the sectionsizes of the beam make the beam-end moment and the mid-span moment are similar ortoward equilibrium in the process of structures design, then the materials will be fully used tomake the designed structures safer and more economic.In order to analyze the relation of the section sizes of beam-column and the forcedistribution of the nodes in theory, this paper has analyzed the connection between structuralinternal force by the changes of beam and column section size. The internal force of the framemodel is calculated and analyzed under various section sizes. The range of stiffness ratio ofthe beams and columns is found which made the moment of the beam-end and the mid-spanhave few differences by comparing the moment of the end of the rod and the mid-span. Theresults shows that: the internal force distribution of the frame structure has little differencewhen the line stiffness ratio K is in the range of0.7~1.3, under the condition of ignoring bothaxial and shear deformations. The internal force distribution of the frame structure isrelatively balanced. In this way we could reach the purpose of the optimization on the sectionsize of beam-column.In the paper, the research is based on the office building of the brewery of Jinzhou,through building two structure models of different storeies. The seismic performance andeconomy are calculated and analyzed under the current structure design codes by using seriesstructure analysis software PKPM. The research shows that: the structure is economic, whenthe line stiffness ratio K is in the range of0.7to1.1by considering line stiffness ratio of thebeams and columns, which could meet the relatively balanced range of0.7~1.3. At this point,the beam height of the cross section is as1/12as the span.