适用于高烈度区多层框架的两阶段抗震设计方法.pdf

39．适用于高烈度区多层框架的两阶段抗震设计方法 刘俊陈亚春 (香港华艺设计顾问(深圳)有限公司，深圳518031) 摘要：汶川地震震害表明，柱端弯矩增大系数不足导致依据现行规范设计的框架结构 在地震中难以呈现“强柱弱梁”的延性耗能机制。本文提出了一种适用于高烈度区多层框架 的两阶段抗震设计方法。首先采用区域抗震设防区划提供的较小的水平地震影响系数最大值 进行位移验算和框架梁的配筋设计，然后采用《抗规》提供的较大的水平地震影响系数最大 值进行框架柱配筋设计。静力弹塑性分析结果表明，按该方法设计的框架结构在罕遇地震作 用下将呈现良好的耗能机制。最后给出了两水平地震影响系数最大值比值的合适范围。 关键词：高烈度；两阶段设计法；强柱弱梁；静力弹塑性分析 A two‘‘phase seismic design method appropriate to multi_‘storey frame structures in highly seismic region I，iu Jun Chen Yachun (Hong Kong Hua Yi Designing Consultants(S Z)LTD．，Shenzhen 518031，China) Abstract：The Wenehuan eamhquake damage show that it is difficult for a frame structure de— signed according to the present code tO realize the ductile energy dissipation mechanism of strong colurnn and weak beam for the deficiency of the moment augment factor of colulTtn．A two—phase seismic design method appropriate to multi—storey frame structures in highly seismic region is presented．Firstly。the relatively small maximum horizontal earthquake affecting coefficient given in regional seismic fortification division is proposed to be used for the displacement verification and reinforcement design of the frame beams．Then the relatively large horizontal earthquake af- fecting coefficient given in seismic code is used for the reinforcement design of the frame col～ umn．The static elasto-plastic analysis results show that the frame structure designed according to the two-phase method can perform good energy dissipation mechanism under rare earthquake．Finally，the appropriate scope of the ratio between the two maximum horizontal earthquake affecting coeffi— cients is provided． Keywords：high intensity；two-phase design method；strong colunTrl and weak beam；static elas— tie-plastic analysis 1 引言 高烈度地区(抗震设防烈度为8度以 上)由于地震作用很大，使得即便是结构总 高度在20m以下的多层建筑，其结构设计 也变得比较困难。框架结构以其灵活的建 筑布置，较好的抗震性能是常规多层建筑 设计的首选方案。然而在高烈度区，为了 满足《建筑抗震设计规范》[1](以下简称 《抗规》)弹性层间位移角限制的要求，柱、 梁断面通常将被设计得非常大，以致感觉 不够经济和影响建筑使用。 一460— 39．适用于高烈度区多层框架的两阶段抗震没计方法 另一方面，汶川地震经验表明[2’3]，常 阶段1：根据区域抗震设防区划提供 规设计的框架结构难以呈现“强柱