王新堂        （宁波大学建筑工程与环境学院  宁波 315 211）

[提要]  基于拉索式平面预应力钢桁架的计算模型，建立了拉索式平面预应力钢桁架优化设计方法。利用该方法分别对工程中常见的三种不同的拉索式预应力平行弦钢桁架进行了优化分析，并对结构方案进行了比较。在此基础上，通过大量计算进一步讨论了这种结构的整体刚度条件、外荷载与钢索预拉力、所需钢索截面面积及总用钢量等因素间的内在关系（由一组曲线表示），为拉索式预应力钢桁架结构方案的选取和设计提供了一种新的途径。
[关键词]  拉索式预应力  平行弦钢桁架  优化设计  方案讨论

On the basis of the computational model of the cable-prestressed planar steel trusses, the methods for optimum design of the structure are further put forward. Using the method presented here, optimization are made for three type of different structures of the planar prestressed steel trusses with parallel cords, and some comparison are made for the structure plans.The relations of the factors such as the stiffness condition of the whole structure, external loads, the pretension of the steel cables, the needed areas of the cables and the total steel consumption are studied through a large amount of calculations, and expressed as a set of curves, which provide a new way for plan choosing and design of the planar prestressed steel trusses.
Keywords: cable-prestressed planar steel truss; parallel cords;  optimum design;  plan discussion