Firstly, when cutting the Tunnel Roof Support with a gas cutting machine, the slits are not straight, some are wavy, and some cutting angles are inconsistent with the angle required by the downhole site, resulting in the joints of the Tunnel Roof Support beam legs not being seamed. The Tunnel Roof Support that was erected was not secure enough, and the support and stability were greatly reduced.
Secondly, most of them failed to design a slab or a slab at the lower end of the Tunnel Roof Support slab. Therefore, the amount of erection of the erection in the roadway where the surrounding rock is relatively broken and the pressure is too large, resulting in a narrowing of the roadway section. Affect the safe use of the roadway.
Third, the processing and cutting of the Tunnel Roof Support is arbitrarily large, and the size of the Tunnel Roof Support is not tight. As a result, when there are individual miners cutting steel, it will be regarded as a qualified product for the long-term or insufficient size. After the deviation of the size of the roadway specification exceeds the specified value, the quality of the support is unqualified, which has a serious impact on the quality of the roadway engineering, and also brings various safety and quality problems to the future reuse.
