强梁弱柱型框架的变形能力及塑性变形累积

On Deformation Limits and Cumulative Deformation of Reinforced Concrete“Strong Beam and Weak Column”Frame Structures

对钢筋混凝土强梁弱柱典型框架的算例进行了非线性全过程分析,首次对该类框架在不同轴压比下而分别成为大、小偏心受压时的变形能力进行了探索;对算例按8度区设计裂度进行了弹塑性地震反应分析,以杆端塑性铰的累积特性为依据,探讨了该类框架作为抗震结构时的累积变形限度.

The 1989 P.R.C.specification《GBJ11-89》stipulated“Strong Column and Weak Beam”as beingsuitable for most reinforced concrete frame structures,and laid down requiremnts for minimum deformation limits.In some P.R.C.industries,such as the Ministry of Metallurgy Industry,the Ministryof Aero-space Industry,etc.,the prevalent type of reinforced concrete frame structure belongs to“StrongBeam and Weak Column”and in such industries,future reinforced concrete frame structures still have tobe of the“Strong Beam and Weak Column”type.The《GBJ11-89》leaves“Strong Beam and WeakColumn”problem to future consideration.The contributions of this paper are:(1)My research results indicate that,for typical examples of R.C.(reinforced concrete)frame struc-ture,requirements by《GBJ11-89》for rainimun deformation limits can also be satisfied for“StrongBeam and Weak Column”type.In order to assure minimum deformation limits,the designers need onlyto be careful that axial forces on column are below their critical values.(2)My research gives the minimum capacity for cumulative deformation of R.C.frame structure of“Strong Beam and Weak Column”type in order to provide against an earthquake which is“8”in《GBJ11-89》.My research includes experiments on a scaled-down model;this model is subjected to amaximum acceleration of 600mm/s^2(or 60 gal)corresponding to 3500mm/s^2 for 350 gal) for thefull-scale structure;the model is subjected to several standard waves of“earthquake”.Such a minimumcapacity is based on the assumption that there is no limit on the maximum relative horizontal displace-ment.