【摘要】 常规抗震设计中的R-μ关系是实现结构抗震性态控制所必须掌握的关键规律,我国规范在R-μ关系上与国外有影响规范之间存在着较明显差异。为了判明这种差异对结构抗震性态的影响,完成了严格按我国现行规范设计的各设防烈度分区的典型钢筋混凝土框架结构在多条地面运动输入下的系列非弹性动力反应分析,对这些结构在强震下的非弹性反应性态进行了初步的识别。结果表明,9度区一级抗震等级的柱抗弯能力增强措施及构造措施有效,所形成的以梁铰为主的反应性态预计能较好满足预定的抗震性态要求;而二、三级抗震等级的8度和7度区框架在强震下形成了柱端塑性铰偏多或占主导地位的塑性耗能机构,导致层侧移机构出现的风险增大;与一级抗震等级框架相比,二、三级抗震等级框架的抗震性态相对偏不利。以此为基础,从逐步实现各设防烈度分区结构"等抗震安全性"的目标出发,对我国规范中有关抗震措施规定提出了进一步优化的建议。更多还原

【Abstract】 In general seismic design, the R-μ relationship is a key rule for seismic performance control of earthquake-resistant structures. The R-μ relationship in Chinese codes is quite different from those in foreign influential codes. To find out the influence of this difference on seismic performance of structures in China, typical reinforced concrete frames in different seismic fortification zones were designed strictly conforming to the Chinese codes, and series of nonlinear dynamic analyses of these structures were carried out with input of ground motion groups. The nonlinear response performances of these structures under strong earthquakes were verified preliminarily. The results indicate that: the frame for Earthquake-resistant Grade I(in zones of Earthquake Intensity 9) develops a beam-hinge-dominated mechanism and can satisfy desired seismic performance demands due to the effective column-moment-enhancing-measure and other seismic measures; both the frame for Earthquake-resistant Grade II(in zones of Earthquake Intensity 8) and the frame for Earthquake-resistant Grade III(in zones of Earthquake Intensity 7)develop a column-hinge-dominated mechanism, which may increase the risk of the occurrence of story-sway mechanism; seismic performances of the frames for Earthquake-resistant Grade II and III are relatively unfavorable compared with those of the frame for Earthquake-resistant Grade I. Based on these results, proposals on further optimization of seismic fortification measures in the Chinese codes are put forward, aiming to gradually realize the‘equivalent earthquake-resistant safety’of structures in different seismic fortification zones.更多还原