严寒地区大跨度拱形钢棚的设计要点及有限元分析

DESIGN POINTS AND FINITE ELEMENT ANALYSIS OF LARGE-SPAN ARCHED STEEL SHED IN SEVERE COLD REGION

大跨度拱形钢棚作为施工临时结构,跨越冬期时需承担雪风荷载的共同作用,但工程界对这类结构的设计要点尚不明晰。文中基于东北严寒地区某地铁工程,采用MIDAS软件建立了拱形施工钢棚三维模型,并基于有限元分析结果对既有拱形钢棚进行了结构优化设计、总结了该类结构的设计要点。研究结果表明,大跨度拱形钢棚的三维结构设计应考虑风荷载的风向角的影响,并计入雪荷载(活荷载)及结构自重的综合作用;加强柱间横向连接可有效抵抗竖向荷载作用下拱形钢棚产生的水平侧移;通过设置适当的人工除雪机制,可有效降低该类结构的设计成本。

Large-span arched steel sheds, as temporary construction structures, are designed to bear the combined effects of snow and wind loads during winter, but the design points of such structures are still unclear. Based on a subway project in the severe cold region of northeast China, this paper established a three-dimensional model of arched steel shed by MIDAS. Based on the results of finite element analysis, the structural optimization design of the arched steel shed is carried out, and the design points of the structure are summarized. The results show that the three-dimensional structure design of large-span arched steel shed should consider the influence of wind load under different directions, and take into account the combined effects of snow load (live load)and self-weight. Strengthening the horizontal connection between columns could effectively resist the horizontal lateral displacement of arched steel shed caused by vertical load. The design cost of such structures can be effectively reduced by providing an appropriate artificial snow removal mechanism.