拱型波纹钢屋盖下部支承结构的设计与分析

Design and analysis on lower supporting structure of arched corrugated steel roof

主要针对拱型波纹钢屋盖结构的钢与混凝土两种下部支承结构在实际设计中的问题和影响因素等问题展开分析。根据拱型波纹钢屋盖结构的受力特点,建立了下部结构的计算模型。算例分析表明:跨度、矢跨比对拱脚水平推力影响均较大;矢跨比较大、柱高较小或柱距6m左右时,拱型屋盖下部采用钢结构较经济,而对于小跨度(尤其是跨度为18m左右)时,采用钢支承结构不够经济。建议通过梁端加肋或采用箱形截面钢梁减小拱脚水平推力的扭转影响。此外,按照悬臂梁对称配筋的方式对下部混凝土柱进行设计较简单方便且误差很小。

A series of problems and influencing factors in the design of two kinds of lower supporting structures by using steel and concrete are analyzed on the arched corrugated steel roofs. According to the mechanic performance, the analytical models of lower supporting structures are built. The numerical examples show that both the effective span and the ratio of rise to effective span have vital effects on the horizontal forces at the skewback of arched corrugated steel roof. It is more economic to adopt steel structures as the lower supporting ones, when the ratio of rise to effective span is relatively larger, the height of column is smaller, or the column distance is around 6m. However, for small effective span （especially a 18-meter span）, it＇s not economic. It is suggested to add stiffener at the beam ends or use box-section beam to reduce torsion effects induced by the horizontal forces at the skewback of the roof. In addition, it is more facilitated and accurate to design the concrete lower structures as cantilever beam by symmetrically disposing reinforcing bar.