【摘要】 汶川地震中损坏的楼板与梁整体现浇的钢筋混凝土框架结构几乎全部是"强梁弱柱"型破坏,这是由于多年来建筑设计中,框架梁的钢筋配置过多和抗震设计规范中规定的框架柱相对于框架梁的受弯强度放大系数偏小。2010年颁布实施的《建筑抗震设计规范》(GB 50011—2010)适当提高了该放大系数,但仍不能根本解决地震时柱先于梁破坏的问题。分析混凝土结构设计的全过程,发现"强梁弱柱"型破坏的主要原因,即该种结构的梁上部配置钢筋过多。对罕遇地震作用下减少梁上部钢筋的两个实际工程进行弹塑性时程计算,结果表明:减少梁上部钢筋可改善楼板与梁整体现浇混凝土框架结构的抗震性能,同时降低了造价,且方便施工。更多还原

【Abstract】 Almost all of the damaged cast-in-place reinforced concrete frame structures in the Wenchan earthquake are in the form of strong-beam and weak-column mechanism damage.Too much top-reinforcement than required at beam ends and too small moment amplification factor of the columns have caused "strong-beam and weak-column" damages.Code for seismic design of buildings GB 50011—2010 increased the moment amplification factor for columns,it is still not enough to stop the fact that columns are more prone to damage than beams.Elasto-plastic time-history analyses are conducted for two structures with reduced reinforcements in the upper part of the beams,subjected to rare earthquakes.The results show that the seismic performance of the cast-in-place reinforced concrete frame structures has been greatly improved and the construction costs reduced.更多还原