薄壁型钢檩条抗积雪荷载作用的设计方法研究  

Design Method of Thin-walled Steel Purlins under Snow Load

作　　者：曹平周[1] 董先锋[1] 赵文涛[1] 

机构地区：[1]河海大学,南京210098

出　　处：《建筑科学》2009年第11期5-9,共5页Building Science

摘　　要：近年来我国多次发生在积雪荷载作用下门式刚架轻钢房屋发生破坏事故。本文分析了积雪荷载在房屋屋面形成的特点和屋面积雪荷载作用下薄壁型钢檩条的破坏特征。探讨了现行设计规范和技术规程中檩条抗积雪荷载设计方法的合理性,指出了计算模型存在的不足。压型钢板屋面在积雪荷载作用下,不宜作为檩条可靠的侧向支撑,檩条计算应按屋面不能阻止檩条侧移和扭转进行强度和稳定计算。通过大量算例计算和分析比较,研究了屋面坡度与扭转翘曲正应力对檩条截面正应力的影响规律和程度,指出了现行设计规范和技术规程中薄壁型钢檩条抗积雪荷载的设计方法的适用性和缺陷。对于目前大量采用的屋面坡度较小的轻钢建筑檩条进行强度和稳定计算时,不宜忽略扭转翘曲正应力的影响。探讨了在屋面积雪荷载作用下门式刚架轻钢房屋发生破坏的原因。提出了薄壁型钢檩条抗积雪荷载作用的设计方法建议。In recent years, light weight steel portal frame plants were damaged many times by snowstorm in our country. This paper presents research and analysis about the features of snow load formed on house roof and the destruction characteristics of steel purlins under the snow load. Furthermore, the rationality of the steel purlins＇ design method in the present design standard and the technical specification, and the insufficiency of computation model are discussed and pointed out in this article. Profiling steel plate roofing isn＇t suitable for the reliable lateral strut of the steel purlins. The computation of the steel purlins＇ intensity and stability should be carried on in condition that the move and torsion of the steel purlins can＇t be stopped by roof. Many examples of calculation and analysis were done to research the law and the extent of impact on the purlins＇ cross-section stress of the roof slope and the warping normal stress. Then the applicability and shortcomings of design method on cold-formed steel purlins under the snow load presented in the current design standard and the technical specification are pointed out. For the large number of light weight steel construction with smaller roof slope, when calculating the intensity and stability of the purlins, the impact of the warping normal stress should not be neglected. The causes of damage of the light weight steel portal frame housing under the snow load were discussed. In the end, the advices of design method on the thin-walled steel purlins under the snow load are presented.

关 键 词：薄壁型钢檩条 积雪荷载 计算模型 扭转 翘曲应力 

分 类 号：TU392.1[建筑科学—结构工程] TU312.1