Synthetic Study on Seismic Resistant Design of RC Structures Considering Rational Ultimate Deformability

本文通过对前人研究成果的回顾、荷载试验和钢筋混凝土构件非弹性变形及弯矩-曲率关系的分析，得出以下结论。本文的研究结果为钢筋混凝土结构抗震设计提供了理论依据。1.通过对已有试验结果的分析，在假定受剪钢筋对构件延性贡献与其他因素无关的前提下，推导了钢筋混凝土构件延性系数的计算公式。对钢筋混凝土构件弹塑性区性能的有限元分析结果表明，在地震作用下，钢筋混凝土构件的弯曲延性系数不仅与反复荷载作用下的延性系数不同，而且受波浪特性的影响也很大。3.当提供足够的抗剪钢筋以使弯曲屈服后的剪切破坏不发生时，通过独立地评价杆部变形、塑性铰区变形和纵向钢筋拔出变形，可以将弯曲延性系数转换为曲率延性系数。为了更准确地计算塑性铰区的变形，必须采用考虑纵筋屈曲的模型。4.编制了钢筋混凝土构件弯矩-曲率关系、几何非弹性变形和振动响应分析程序。这些程序基本上适用于评估钢筋混凝土墩的抗震性能。

The following conclusions were derived from the results of review of previous papers, loading tests and analysis on inelastic deformability and moment-curvature relationship of RC members. All of the results make it possible to rationalize seismic resistant design of RC structures when taken into the previous designing system.1.Equations to evaluate flexural ductility factor of RC members were derived through analysis of the previous test results assuming that contribution of shear reinforcement to ductility is independent from that of factors other than shear reinforcement. These equations have better applicability to such members that shear failure takes place after flexural yielding.2.It was show by the results of FEM analysis on the behaviors of RC members in inelastic region that flexural ductility factor under seismic excitations is not only different from that under repeated cyclic loading, but also influenced significantly by the characteristics of the waves.3.When shear reinforcement is provided sufficiently so that shear failure after flexural yielding does not take place, it is possible to convert flexural ductility factor into curvature ductility factor by evaluating deformation of stem part, deformation of plastic hinge region and deformation due to pulling-out of longitudinal reinforcement independently. In order to evaluate the deformation of plastic hinge region precisely, it is important to adopt a model in which buckling of longitudinal reinforcement is taken into account.4.Programs to analyze moment-curvature relationship, geometrically inelastic deformation and vibration response of RC members were developed. These programs are applicable to evaluate seismic resistant performance of RC piers substantially.