(西安建筑科技大学土木工程学院710055)

［提要］单层房屋钢支撑体系的设计，长期以来只考虑风力和吊车制动力。实际上支撑杆件因被撑构件的几何缺陷而承受支撑力，十字交叉斜撑又因被撑构件的压缩变形而产生附加压力。指出这两种内力不应被忽视，并给出了有关计算公式。对设计中如何计算屋架上弦横向支撑和柱间支撑提出了建议，指出吊车梁下的交叉支撑不应作为拉杆看待。

［关键词］单层房屋  钢支撑体系  支撑力  附加压力  十字交叉斜撑

Internal Forces and Member Calculation in Steel Bracing System of Single Storey Buildings/Chen Shaofan (School of Civil Engineering,Xi"an University of Architecture & Technology,Xi"an 710055,China)

Abstract:Since a long period,only wind load and longitudinal braking force are taken into account in the design of steel bracing system of single storey buildings. Actually,bracing members are subject to bracing force owing to the geometric imperfection of braced members. Furthermore,subordinate compression occurs in cross diagonal braces owing to the compressive deformation of braced members. It reveals that these two kinds of internal force must not be neglected and gives relevant calculation formulas. Suggestions are made regarding the calculation of truss upper-chord transverse bracings and inter-column bracing,indicating that cross bracings underneath crane girders should not be treated as tension members.

Keywords:single storey building; steel bracing system; bracing force; subordinate compression; cross diagonal bracing