[提要]  结合实际工程设计，选取轻型薄壁钢管拱形屋盖的矢高、拱形桁架高度、杆件截面面积作为优化设计变量，以轻型钢管拱形屋盖的总造价最低为目标函数，建立了优化设计的数学模型，采用直接搜索法与准则法有机结合的综合优化设计方法，按规程的要求对轻型钢管拱形屋盖的几何外形及杆件的截面进行了综合优化设计，考虑了各种情况的荷载作用，编制了SLAOP软件。在中小跨度情况下，采用本文方法设计的轻型钢管拱形屋盖体系综合造价比传统结构体系的节约10%，而且具有屋盖体系轻、荷载小、施工不受季节限制、周期短等优点，具有良好的经济效益和发展潜力。
[关键词]  轻型钢管  拱形屋盖  数学模型  综合优化设计  经济效益

Combined with an actual project design of the light steel tube truss,the arch rise ancl height of the arch truss, as well as the cross-sections of the steel tubes are taken as the design variables. The total cost of the arch truss roof is taken as the objective function. According to the code, the mathematical mode is established that the combination of the direct searching and criteria methods is adopted as the comprehensive optimum method.A variety of loads acting on the truss structure are considered and a programm named SLAOP is performed for the optimum clesign of the truss structure. The conclusion of the calculations shows that the comprehensive cost of the roof structure with the small and middle span truss may decrease about 10%  than traditional structure. It has the advantage that the roof system is light, the dead load is small, the construction period is short and the construction is not confined by the season.
Keywords:  light steel tube; arch roof;  mathematical mode;  comprehensive optimum design;  economic benefit