自重作用下跨度对钢支撑稳定性影响研究

STUDY OF EFFECT OF SPAN ON STABILITY OF STEEL SUPPORT UNDER SELF-WEIGHT

钢支撑长细比大,在自重与预加轴力作用下会产生挠度变形与附加应力,跨度过大时极易出现失稳破坏,以武汉天河机场深基坑支护为工程依托,分析研究自重作用下不同跨度钢支撑产生的挠度变形及稳定性,得到以下结论:钢支撑跨度增加时挠度变形前期呈线性增长,后期呈指数行增长;单跨跨度超过25m时钢支撑的稳定性达不到要求,需增设格构柱.

The steel support with large slenderness ratio will produce deflection deformation and additional stress under the action of self-weight and pre-axial force.When the span is too large,it is easy to appear instability.Based on the deep foundation pit support of Wuhan Tianhe Airport,the deflection deformation and stability of steel support with different span under the action of self-weight are analyzed,and the following conclusions are drawn:When the span of steel support increases,the deflection increases linearly in the early stage of deformation,and increases exponentially in the later stage;when the span of single span exceeds 25 m,the stability of steel support will not meet the requirement,and lattice columns should be added.