广西钦州市体育场钢结构整体稳定性设计

Overall Stability Design of Steel Structural for Guangxi Qinzhou Stadium

广西钦州市体育场空间造型复杂,包含东、西两看台,看台下部为钢筋混凝土框架结构,上部采用大跨度悬挑钢结构。屋盖主桁架通过支座支承在高差悬殊的混凝土结构上,主支撑结构采用前锥型-后V型支撑,形成的结构传力途径简单明确。但每一单榀大悬挑主钢架容易形成瞬变机构,由于各榀主悬挑结构及其支撑在空间上具有不同的x、y、z坐标而不共面,各榀间又通过相应的结构联系桁架形成稳定的整体结构。本文为了研究屋盖钢结构整体稳定性,根据各荷载工况响应计算,确定了恒、活荷载及风荷载为主要控制荷载,从而以相应的荷载组合来计算整体稳定系数,在计算上验证了整体结构稳定性。计算方法采用Sap2000程序对钢结构进行了线性特征值屈曲计算,并考虑初始几何缺陷,其中风荷载采用风洞实验结果。屈曲计算结果表明,钢结构整体稳定性满足安全要求,具有足够的屈曲安全系数。钢结构的整体稳定性也需在结构布置、支座设计及相应节点设计上的保证。

Guangxi Qinzhou stadium is a special structure with complicated features, containing two stands. The bottom of the stand is reinforced concrete frame structure. The roof main structure is a big span cantilever steel structure. The main steel truss is supported by concrete structure. Supporting system contains front supporting like cone formed by four steel rods and back supporting like V-shape formed by two steel rods. So the big span cantilever structure and its supporting system will make the structure transfer road to force very simple. But each lonely big span cantilever frame may be a transient mechanism. Fortunately, each main frame and its supporting form space structures have not same x, y or z coordinate, all main frames connect together through contact truss to form a stability structure. In order to study roof steel overall stability, on base of the analysis result of each load case, the control load cases include dead load, live load and wind load. The whole stability factor is found for each corresponding load combination, all factors verify the whole stability of structure. Sap2000 program has been used to find the analysis result of eigenvalue buckling, and geometry original bug is considered. The wind load distribution on the surface is from a wind tunnel test through a rigid model. Through the buckling analysis,the steel roof structure can pass buckling analysis and behave stability with high safety factor. The overall stability also needs reliable array of structure,supporting design and all correstmnding ioint design.