(1 同济大学土木工程防灾国家实验室，上海 200092； 2 重庆大学土木工程学院，重庆 400045； 3 上海江欢成建筑设计有限公司，上海 200002)

［摘要］根据现行《建筑钢结构防火技术规范》(CECS200：2006)中简支组合梁抗火承载力验算方法，提出了简支组合梁抗火设计的临界温度法，给出了临界温度的计算方法。对影响简支组合梁临界温度的参数分析研究发现：在确定的荷载比下简支组合梁的钢梁截面、材料强度、有效宽度等对简支组合梁的临界温度的影响较小，而耐火极限和楼板厚度对简支组合梁临界温度影响较大。给出了一般简支组合梁在不同楼板厚度、不同耐火极限下，不同荷载比对应的临界温度，可供工程设计使用。

［关键词］简支组合梁；荷载比；临界温度；耐火极限

Simplified approach for fire-resistance design of simple-supported composite beams

Li Guoqiang¹, Wang Weiyong², Zhou Hongyu³(1 School of Civil Engineering, Tongji University, Shanghai 200092, China; 2 School of Civil Engineering, Chongqing University, Chongqing 400045, China; 3 JIANGS Architects & Engineers, Shanghai 200041, China)

Abstract:Based on the fire resistance validation method in current Technical Code on Fire safety of Steel Structure, critical temperature method for fire resistance design of composite beams is proposed. The calculation method of critical temperature is presented. Parameters affecting the critical temperature are analysed. The results show that at a definite load level, section shape of steel beams, material properties and effective width have little influence on the critical temperature of simple-supported composite beams. However, the fire duration and depth of slabs have significant influence on the critical temperature. The critical temperature of normal simple-supported composite beams, at various slab depth and fire duration, is given to provide a reference for engineering.

Keywords:simple-supported composite beams; load level; critical temperature; fire duration

作者简介：李国强(1963-)，教授，博导，Email:gqli@tongji.edu.cn。

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