我国“强柱弱梁”措施表达式影响因素分析

Analysis on factors influencing the mathematical formula of strong column-weak beam measures in China

对于按中国规范分别设计的位于不同设防烈度分区、不同抗震等级的2个空间框架和5个平面框架,通过考察各节点的四类弯矩比计算结果,讨论了楼层位置、烈度区、梁跨度、现浇板钢筋、梁底纵筋"超配"等因素对"强柱弱梁"措施的影响规律。结果表明,采用《建筑抗震设计规范》(GB 50011—2010)式(6.2.2-1)进行"强柱弱梁"调整时,低烈度区框架应同时考虑现浇板钢筋、梁底纵筋"超配"的影响,高烈度区框架可主要考虑现浇板钢筋的影响;确定现浇板钢筋的增强幅度、梁底纵筋的"超配"幅度时均需考虑烈度区、楼层位置、梁跨度的影响。

Two RC space frames and five RC plane frames in different earthquake intensity regions and with different seismic precautionary criteria were designed according to Chinese code. The influencing laws of the floor location,earthquake intensity region,span of beam,reinforcement of cast-in-place slab and over-reinforced bottom longitudinal bars of beam on the strong column-weak beam measures were discussed based on the calculating results of four types of bending moment ratios of each node. The results show that when formula(6. 2. 2-1) in Code for seismic design of buildings( GB 50011—2010) was adopted for the strong column-weak beam measures,the effect of reinforcements of cast-in-place slab and over-reinforced bottom longitudinal bars of beam should be considered for the frames in lower earthquake intensity regions,while the effect of reinforcements of cast-in-place slab should be mainly considered for the frames in higher earthquake intensity regions. The influences of earthquake intensity region,floor location and span of beam should be considered when the increase range of reinforcements of cast-in-place slab and over-reinforced bottom longitudinal bars of beam were determined.