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

通过对相关文献的回顾、荷载试验和钢筋混凝土构件的非弹性变形能力及弯矩曲率关系分析，得出以下结论。这些结果为将钢筋混凝土结构抗震设计纳入原有的设计体系中进行合理设计提供了可能。通过对以往试验结果的分析，在剪力配筋对延性的贡献独立于除剪力配筋以外的其他因素的前提下，推导出钢筋混凝土构件抗弯延性系数的计算公式。这些方程对受弯后发生剪切破坏的构件具有较好的适用性。非弹性区钢筋混凝土构件的有限元分析结果表明，地震作用下的抗弯延性系数不仅与反复循环荷载作用下的抗弯延性系数不同，而且受地震波特性的显著影响。当有足够的抗剪钢筋，使其不发生弯曲屈服后的剪切破坏时，可以通过单独评估杆部变形、塑性铰区变形和纵向钢筋拉拔变形，将抗弯延性系数转化为曲率延性系数。为了准确地评估塑性铰区域的变形，采用考虑纵向钢筋屈曲的模型是很重要的。开发了分析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的程序。这些程序基本上适用于评价钢筋混凝土桥墩的抗震性能。

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.