(1 同济大学土木工程学院， 上海 200092；

2 悉尼大学土木工程学院, 悉尼 NSW2006;

3 同济大学土木工程防灾国家重点实验室， 上海 200092; 4重庆大学土木工程学院, 重庆 400045)

［摘要］通过对现有组合梁抗火设计方法的总结和对比分析发现，中国规范和欧洲规范中承载力法在构件温度和承载力的计算上都基于相同的理论，只是某些参数的取值不同，最大的区别在于欧洲规范强调了对高温下剪力连接件抗剪承载力的验算，中国规范则没有考虑这一影响，而英国规范则基于试验研究的结果，给出了近似的计算公式。对于临界温度法，各规范均以表格或简化公式形式给出了临界温度计算方法，但只有英国规范考虑了常温下抗剪连接程度的影响。通过将各规范计算结果与现有相关试验结果进行对比发现，组合梁抗火设计时，应考虑常温下抗剪连接程度的影响；在现有中国规范组合梁抗火设计方法中考虑常温下剪力连接程度后，能更准确地预测组合梁的临界温度。

［关键词］组合梁； 栓钉； 抗火设计； 剪力墙连接程度

中图分类号：TU3171，  TU973257文献标识码：A文章编号：1002-848X(2015)11-0070-05

Improvements of fire design specifications for composite beams

Chen Lingzhu1, 2， Li Guoqiang1,3， Jiang Shouchao1,3， Wang Weiyong4，   Ranzi Gianluca2

(1  College of Civil Engineering, Tongji University, Shanghai 200092, China；

2 The University of Sydney School of Civil Engineering, Sydney NSW2006, Australia;

3 State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China;

4 School of Civil Engineering, Chongqing University, Chongqing 400045, China)

Abstract:Through summarizations and comparisons of current fire design methods for composite beams, both Chinese and European codes were found to be based on a similar theoretical approach called bearing capacity method for the evaluation of the moment capacity and its associated temperature field, with differences only related to the actual values assigned to a number of parameters. The biggest difference was that  Chinese code does not have a design check for the shear capacity of shear connectors at elevated temperatures but  European specifications do. And the approximate formula was provided based on test data in  British code. For the limiting temperature method, tables or simplified equations were suggested to obtain the limiting temperatures in Chinese, European and British codes, while the influence of the degree of shear connection at room temperature was included only in  British code. The importance in accounting for the influence of the degree of shear connection at room temperature in the fire design was highlighted from the comparisons carried out between calculated and measured test results. Based on these considerations, a suggestion for the Chinese code was presented to account for the shear capacity of shear connectors at elevated temperatures. The proposed method was shown to provide better prediction for the limiting temperatures of composite beams than the existing method in Chinese code.

Keywords:composite beam; shear stud; fire design； degree of shear connection

*土木工程防灾国家重点实验室开放课题(SLDRCE-MB-05)。

作者简介：陈玲珠，博士研究生，Email: 2lingzhuchen@tongji.edu.cn。

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