Evaluation system of details of reinforcement arrangement and reinforcing method on seismic performance of RC columns

(1)钢筋混凝土多裂纹本构模型建立了含四个独立固定裂纹的钢筋混凝土本构模型。并通过反循环作用下的实验验证了其有效性。因此，有限元分析的应用范围可以扩展到多向荷载或地震作用与恒载耦合的复杂荷载条件下。(2)RC/PL区的配筋方法和分区方法根据配筋的具体情况，提出了适用于部分加固的大型钢筋混凝土柱或梁的粘结应力传递区(RC区)和另一区(PL区)的简单确定方法。对于钢筋混凝土柱，无论配筋率和配筋率，钢筋混凝土柱的延性均可用来预测。对钢筋混凝土柱进行了三维分析和多向力响应分析，通过对多向受剪力的短柱和不同比例的梁在弯矩和剪力作用下的数值分析，证实了屈服前抗剪强度的尺寸效应。(4)钢筋混凝土框架结构抗震性能验算体系的建议对于钢筋混凝土框架结构，通过比较三维非线性动力分析计算得到的构件所受的两个方向剪力与(3)中所述的承载力，提出了钢筋混凝土框架结构的抗震性能验算体系。并将该体系应用于1995年阪神大地震中受损的铁路框架结构，验证了该体系的有效性。

(1) Constitutive model for multi-cracked reinforced concreteConstitutive model for reinforced concrete with four independent fixed crack was developed. And its effectiveness has been verified by the experiment under reversed cyclic actions. As a result, the application of FEM analysis can be extended up to the complex loading conditions such as multi-directional forces or seismic actions coupled with dead load.(2) Details of reinforcement arrangement and zoning method for RC/PL zoneThe simple method to determine the zone with bond stress transfer mechanism (defined as RC zone) and the other zone (defined as PL zone) applicable for large scale RC columns or beams reinforced partially has been proposed based on the details of reinforcement arrangement. The shear capacity and the ductility of RC columns can be, regardless of reinforcement ratio and scale, predicted by applying constitutive model mentioned at (1) for RC zone and tension softening model for PL zone.Three dimensional analysis for RC columns and response of multi-directional forcesThe size effect on shear strength prior to yielding has been confirmed by numerical analysis of the short columns subjected to multi-directional forces for shear capacity and deformability and the RC beams with deferent scale subjected to flexural/shear forces. It is furthermore confirmed that the ductility of RC member without side rebars can be predicted appropriately by verification of shear failure after yielding.(4) Proposal of check system of seismic performance for RC framed structuresFor RC framed structures, the system for safety has been proposed by comparing two directional shear forces induced to the members computed by three dimensional nonlinear dynamic analysis with its capacity described at (3). And the validity of proposed system has been verified by applying to framed structures for railway damaged on the Great Hanshin Earthquake 1995.