Study On The Height-width Ratio Of Core Wall For RC Frame-corewall Structures

Compared with other structural forms, frame-corewall structures have a greateradvantage on the performance and available space, so this form has being increasinglyused in China. The height-width ratio of core wall has a great effect on the seismicperformance of this structural forms, however, Researches on the effect of height-widthratio of core wall is inadequate both at home and abroad at present. The limit to theheight-width ratio of core wall is set at12, and not considering different intensity andsite category in the technical specification. In this situation, this paper studies andproposes a restrictive height-width ratio of core wall which considered seismic intensityand site category by the research resultsof the performance in elastic and elastic-plasticstage, and it also has a important theoretical significance and engineering applicationvalue.Firstly, considered with practical engineering and standard codes,24RCframe-corewall structures models with different height-width ratio are established byPKPM、ETABS、MIDAS finite element analysis software in different intensity regionsin this paper, then, these models are analyzed with elastic analysis, pushover analysisand multi-wave dynamic elastic-plastic analysis. The results are as followed，in elasticstage, the height-width ratio, the stiffness, the displacement, the layer displacementangle, the maximum drift floors, the axial compression ratio, and the shear force and thebending moment have a relationship with the height-width ratio, in elastic-plastic stage,height-width ratio affects the displacement, internal force and damage of the wholestructure and its members, the structural members’ yielding sequence and the failuremodes of the whole structure, and the damaging mode.Secondly, models are analyzedwith the displacement, internal force and damage of the whole structure and its members in elastic stage, which meet the storey displacement angle requirement andhave the maximum height-width ratio. Then this paper proposes a limiting value whichconsidered the different seismic intensity and site region to the specification. In addition,three cases in the practical engineering are studied and compared to analyzes the effectof the structures which has additional columns and not, according to specifications inelastic stage and in elastic-plastic stage. Drawing a conclusion that adding columns willaffect the shear force and bending moment of the frame so as to the force of columns,and increase the ductility of structure,while reduce the development of plastic degree.Based on the conclusion of elastic stage analysis results, this article proposes somemethods to add the columns properly and to reduce the height section of frame beams.