矿井井塔剪力滞后效应影响因素分析

Analysis of shear lag effect in mine towers

为了探讨不同因素对矿井井塔剪力滞后效应的实际作用与影响,利用大型有限元分析软件,结合井塔的实际框筒结构进行建模分析。结果显示:角柱截面的变化对剪力滞后效应的影响很小,当角柱截面面积与其他柱的截面面积比在1.185～1.850范围内变化时对剪力滞后系数的影响可以忽略不计;梁柱刚度比的减小使得剪力滞后效应变得严重;结构长宽比L/B越大,剪力滞后效应越显著,在设计框筒结构的长宽比时,应尽量选择将结构布置成为长宽比L/B等于1.0或接近于1.0的设计方案,以减小剪力滞后现象对结构产生的影响,增强结构的整体性;随着结构开洞率的减小,剪力滞后效应的影响减少,且结构底部剪力滞后效应效果较为明显,随着结构高度的增加而呈逐渐下降的趋势,在结构设计时应尽量避免结构开洞过多。

In order to investigate the influence of different factors on the shear lag effect in mine towers, the finite element software combined with the modeling of the frame-tube structure of a mine tower was used for analysis. The results show that the section change of the comer column has little influence on the shear lag effect within a reasonable range, and the shear lag effect coefficient can be ignored when the section area ratio of comer columns to other columns ranges from 1. 185 1. 850; the shear lag effect becomes serious with the decrease of the stiffness ratio of beams to columns. In the design of frame-tube structures, the ratio of length to width should be 1.0 or close to 1.0 so as to reduce the shear lag effect on the structures and enhance the integrity; the greater the length-width ratio is, the more shear lag effect occurs. With the reduction of the rate of holes, shear lag effect is reduced, and the shear lag effect on the bottom of the structure is more obvious and decreases along with the height. Therefore, excessive rate of holes should be avoided in structure design.