李开禧  戴国欣  崔  佳
    （重庆建筑大学  630045）

[提要] 讨论了凹形截面梁由于积水所产生弯曲变形的附加效应。当梁的刚度较小时，积水荷载和弯曲挠度两者之间相互促进，甚至可能形成恶性循环，从而弓l起梁的断裂。当前，大跨空间薄壁结构在工程中的应用日益广泛，研究由于积水荷载引起梁在面内弯髓失稳的概念和控制方法，具有重要的实用价值。
[关键词] 积水荷载 面内弯曲失稳 薄壁构件

Thin-wall structures like U-section beams are easy to gather water. The force of water causes beams bending. Due to the bending deformation of beams, more water will gather in the roof. The interaction of water and deformation will make beams collapse. The additional effect of bending deflection caused by water is discussed.
Keywords: force of water; the bending stability; thin-wall members