强烈地震下结构的合理破坏模式是保证结构抗震能力和实现抗震设防目标的决定性因素之一。然而汶川地震中规范倡导的框架结构的“强柱弱梁”破坏模式几乎未能实现。新版《建筑抗震设计规范》(GB50011—2010)在基于震害及相关研究成果的基础上对钢筋混凝土框架结构的“强柱弱梁”系数等破坏模式控制措施进行了调整。从汶川地震中钢筋混凝土框架结构的破坏现象出发分析了未出现预期破坏模式的原因,并对新版抗震规范采用的改进措施的合理性和有效性进行考察,探讨了结构合瑚破坏模式的评价标准及控制设计方法,可供结构抗震设计参考。
The reasonable failure mechanism for structures under strong earthquakes is critical for ensuring the structure seismic capacity and achieving the seismic fortification objectives. However, the code preferred failure mechanisms for RC frame structures, the strong column weak beam failure mechanism, were rarely realized during the Wenchuan Earthquake. According to experiences and lessons, learned from damages induced by strong earthquake having occurred in recent years home and abroad and relative achievements of research in earthquake engineering, the strong-column weak-beam (SCWB) ratios and other seismic failure mechanism control measures have been largely modified in the new seismic design code (GB 50011--2010). In this paper, the reason why it is difficult to realize the code preferred failure mechanism is checked basing on the damages of RC frame structures in Wenchuan earthquake. The rationality and effectiveness of the modifications in GB 50011--2010 for RC frame structures is quantitatively investigated. And this study also discusses the reasonable evaluation criteria and the control method of the failure mechanisms. The results can provide reference for building design.