(安徽建筑大学土木工程学院, 合肥 230022)

［摘要］喷淋水对高温钢结构的急速冷却会对结构产生很大的冲击。冷却初期，结构的极限承载力有一定程度的增加，而再进一步冷却反而会使其极限承载力降低；在高温钢结构受到低温水的冷却过程中，冷却水温对结构的极限承载力影响较大，同时，温度低于5℃喷淋水的急速冷却过程导致结构极限承载力下降幅度的最低值要比水温高于6℃喷淋水作用时大很多。在冷却初期，极限承载力达到的最大值也随冷却水温的降低而增大，而在冷却过程达到的最低值也要小很多，有时相差达到1倍以上。冷却位置对结构的极限承载力影响很大，在中间跨左侧梁柱节点喷水冷却时对结构的极限承载力影响最大，在中间跨梁的跨中下方次之。温度高于550℃的钢框架在梁柱节点处喷水冷却很可能在短时间内引发结构的破坏性坍塌，而温度低于500℃钢框架在喷水冷却过程破坏的程度要低很多。

［关键词］火灾； 高温; 钢框架； 极限承载力； 喷淋水； 快速冷却

中图分类号： TU392.1 文献标识码： A文章编号：  1002-848X(2016)S1-0583-08

Research on damaged behavior of high temperature steel frame structure

 rapidly cooled by spray water in fire

Xia Yunchun

(School of Civil Engineering, Anhui Jianzhu University, Hefei 230022, China)

Abstract： Spray water had a strong impact on a high temperature steel frame structure in fire. In early cooling, ultimate bearing capacity of the structure increased a little, while further cooling would make the ultimate bearing capacity reduced. During rapid cooling, the temperature of cooling water had a large effect on the ultimate bearing capacity of the structure, the maximum decrease value caused by spray water below 5℃ was much larger than that caused by spray water above 6℃. In the initial cooling, the maximum ultimate bearing capacity also reduced with the increase of cooling water temperature, while its minimum value was much smaller, sometimes the difference was more than 1 time. Location had also a great effect on the ultimate bearing capacity for steel frame structure, it was the maximum when the structure was cooled at the left joint of beam-to-column in fire span, and the second largest effect was at the mid-span of beam in fire span. A steel frame structure, whose temperature was over 550℃, was likely to lead to collapse destructively in a short time when it was cooled at the joints of beam-to-column in fire span, but for the structure, whose temperature was below 500℃, the damage was much lower even it was cooled at the joints of beam-to-column in fire span. 

Keywords： fire； high temperature; steel frame structure； ultimate bearing capacity； spray water； rapid cooling

作者简介： 夏云春，博士，教授，Email:wxiayc@126.com。

*国家自然科学基金(51478002)。