Research On Rational Reinforcement Arrangement Of Special-shaped Columns And Nonlinear Static Analysis On RC Frame With Special-shaped Columns

Special-shaped columns are usually referred to as RC columns with sections T,十,Land Z Special-shaped columns frame structure is a characteristic structure form in China.This structure especially fits the urban multistored buildings and small tall buildings withthe characteristics of no indoor edges and light weight.On the basis calculation results on bearing capacity and ductility of special-shapedcolumns, the rational reinforcement arrangement special-shaped columns with equal legs isdiscussed; In this paper, nonlinear static analysis was processed on a pseudo -static test ofone 1/3-scale model of RC frame with special-shaped columns. The following is mainjobs of this paper:Two nonlinear analysis programs on normal section bearing capacity and ductility ofspecial-shaped columns with numerical integral method are complied. Based on M_x-M_ycurves of 5 optional reinforcement T-shaped columns and L-shaped columns and 4optional reinforcement十-shaped columns with equal legs under different axialcompression ratios, the maximum moments in various loading angles are analyzed. Theeffect of reinforcement arrangement on capacity is discussed. The rational reinforcementarrangement of special-shaped with equal legs is proposed. Based on comparison betweengraphical construction and traditional method, the graphical construction adapting todetermine yield curvature of special-shaped columns is presented; and based on M-Φcurves, optimizing forms of reinforcement are analyzed by graphical construction.Finally, Some suggestions in practice design for special-shaped columns with equal legsare given.The bearing capacity, ductility, plastic hinges occurring mechanism, yieldingmechanism and interstory drift is analyzed and compared between a pseudo -static test ofone 1/3-scale model of RC with special-shaped columns and a nonlinear static analysis bySap2000 (Plastic hinge model using simplified model is simplified by M-Φcurve).According to the analysis, simulating nonlinear behaviour of RC frames withspecial-shaped columns is achieved by the model selected in the paper. The calculatedresults and measured data are in a good agreement. In this paper, effects of analysis modelon stiffness reduction factor and plastic hinge length are discussed, and some suggestionsare presented. Finally, the original test model is reinforced bars according to the rationalreinforcement arrangement of special-shaped with equal legs suggested by this paper. And the results on nonlinear static analysis indicate that the capacity and ductility ofoptimization model is improved at different degree compared with original model.