基于不同规范设计的现役RC框架损伤分析及可修复性能评估

我国现役大多数钢筋混凝土(RC)框架是基于GBJ 11-1989、GB 50011-2001和GB 50011-2010三次抗震设计规范所设计，由于建筑功能的需求，常见框架结构的首层层高明显高于其它层，易导致结构层间变形集中。选择底层层高明显高于其它层的三栋现役RC框架为分析算例，综合考虑填充墙面外变形、节点区剪切变形、柱内钢筋粘结滑移等因素，利用OpenSees有限元分析软件，分别建立其三维空间有限元模型。对三个模型进行了低周往复加载分析和大量地震动激励下的动力时程分析，研究了结构在中震、大震和特大震三个水准下的损伤程度、层间变形的分布模式及可修复性能。结果表明：相对于GBJ 11-1989和GB 50011-2001，基于GB 50011-2010抗震设计规范设计的结构损伤最小，对于潜在薄弱层的加强效果更加明显；中、大震水平，三次规范设计结构发生倒塌的概率均较低，但基于GBJ 11-1989抗震设计规范设计的结构损伤较严重，较难修复；特大震水平，基于GBJ 11-1989和GB 50011-2001抗震设计规范设计的结构倒塌风险较大，基于GB50011-2010抗震设计规范设计的结...

DAMAGE ANALYSES AND REPAIRABILITY EVALUATION OF IN-SERVICE RC FRAMES DESIGNED BASED ON DIFFERENT CODES

Most of the in-service reinforced concrete (RC) frame structures in China were designed based on the three seismic codes of GBJ 11?1989, GB 50011?2001 and GB 50011?2010. Due to the functional requirement, the height of the first story for common RC frame structures is obviously larger than that of other stories, which may result in inter-story drift concentration. Three in-service RC frames, characterized by larger-height first story, were selected as prototypes and their three-dimensional finite element models were built via OpenSees software, considering the factors such as out-of-plane deformation of infilled walls, shear deformation of beam-to-column joints and bond slip of steel bars in columns. The static analyses under cyclic loading and nonlinear dynamic analyses under a larger number of ground motions were conducted for the three models to investigate the damage degree, the distribution pattern of inter-story drift and the repairability performance of the structures under rare and very rare earthquakes. The results show that compared with the structures designed based on GBJ 11?1989 and GB 50011?2001, the structure designed based on GB 50011?2010 suffers minimum damage, and obvious strengthening effect for the potential soft story is observed. Under rare earthquakes, the collapse probabilities of the structures designed based on the three seismic design codes are relatively low, while the structure designed by GBJ11?1989 may develop serious damage and the repairing is impracticable. Under very rare earthquake, the structures designed based on GBJ 11?1989 and GB 50011?2001 have high risk of collapse; while the structure designed based on GB 50011?2010 shows small collapse probability, but the repairing cost is high. With the successive revision of the seismic code, the failure ratio of structural components under very rare earthquakes decreases gradually for the structures designed based on them. The columns of the structures designed based on GB 50011?2001 and GB 50011?2010 mainly present ductile damage, while the columns of the structure designed based on GBJ 11?1989 exhibit obvious brittle damage.