233 / 2023-09-29 10:00:46

Analysis of mechanical characteristics of mine roadway U-shaped steel support under the multi-factor influence.

U-shaped steel support, structural mechanics, mechanical characteristics, multiple factors, internal force diagram, bending moment, axial force

Abstract The failure of U-shaped steel support is mainly characterized by the roof collapse and side local bending of support structure. The method of structural mechanics was used, the three limbs U-steel straight wall semi-circular arch support was taken as an example, and the influence of different vertical loadings, lateral pressure coefficients, retractable joint positions, and height-diameter ratios on the internal force of the support was discussed. The results show that the maximum axial pressure was applied to the roof of support, the maximum bending was applied to the upper part of the support sidewall. The vertical loading and lateral pressure coefficient have the most significant effect on the internal force of support. With the increase of vertical loading and lateral pressure coefficient, the internal force of support changes linearly. However, the influence of the retractable joint position and height-diameter ratio on the internal force of support is weak. Generally, the lateral pressure coefficient and retractable joint position have a great influence on the value and shape of bending moment diagram, for other factors and situations, they only affect the value of internal force diagram, but not the shape of internal force diagram. In practical engineering, the weak part of the roofs support and sidewall should be strengthened properly. Besides, the closer the retractable joint is to the straight wall, the less the bending moment of support. The cross-section area reduced can also decrease the surrounding rock pressure of roadway, and decrease the burden of support structure by reducing the height-diameter ratio.