摘要
从承载能力极限状态的角度出发,通过一个受水平集中力的单层单跨框架模型,研究了钢筋混凝土平面框架结构在水平地震作用下的破坏规律。研究结果表明,在水平力作用下,框架梁端屈服将导致框架柱底端弯矩急剧增大,平面框架结构将提前屈服。这表明框架梁的弯曲刚度对框架的承载力有显著的影响,梁端弯矩调幅将降低平面框架结构的承载力。另一方面,框架梁端屈服以后框架结构的侧移将迅速增长。在水平地震作用下,梁端弯矩调幅将增大框架结构倒塌的风险,结构偏于不安全。当按照《建筑抗震设计规范》(GB 50011—2001)进行设计时,在保证形成"强柱弱梁"破坏机制的前提下,钢筋混凝土平面框架结构不应进行弯矩调幅。
Based on the limit state of bearing capacity, a single-story and singl-span plane frame model was built to simulate the failure of RC plane frame structures under horizontal earthquake action. The structural mechanics analysis shows that the bending moment of column end increases sharply once the beam end fails. As a result, the plane frame structure fails in advance. It indicates that the bending stiffness of beam influences the bearing capacity of of the frame significantly. So the moment modulation method decreases the bearing capacity of plane frame structure under horizontal force. On the other hand, the drift of plane structure increases sharply once the beam end fails. So moment modulation method rises the risk of collapse of plane frame structures under horizontal earthquake action. According to the provisions of the Code for Seismic Design of Buildings （GB 50011-2001 ）, for a strong-column and weak-beam RC plane frame structure, the moment modulation method should not be used under horizontal earthquake action.
出处
《结构工程师》
2010年第4期47-51,共5页
Structural Engineers
关键词
弯矩调幅
地震作用
钢筋混凝土平面框架结构
强柱弱梁
moment modulation, earthquake action, RC plane frame structure, strong-column and weak-beam
