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,从而引起梁的断裂.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曲失稳的概念和控制方法,具有重要的实用价值. The additional effect of the bending deformation caused by water accumulation in the concave section beam is discussed. When the stiffness of the beam is small, both the standing water load and the bending deflection promote each other, and may even form a vicious cycle, causing the beam to break. The application of large-span, space-thin-wall structures in engineering is becoming more and more widespread. It is of great practical value to study the concepts and control methods of bending in-plane bending instability caused by water loads.