Analysis of self drilling hollow bar application in mining support problem

With the development of economy, the coal as main energy demand is becoming more and more huge, coal as the main production in the coal industry is also facing the deep development of the problem, with the increase of excavation depth, roadway supporting faces many difficulties, in order to improve the support strength, enhance security, we need to analyze the application of self drilling hollow bar support in coal mine internal.

Self drilling hollow bar is a direct acting within the surrounding rock of roadway,it is different from the old ways such as wood beams , in other words, it is from the past passive support on the outside of the rock into the internal active support, so that we can reduce the deformation of roadway, improving the bearing capacity of self drilling hollow bar support.

At present，there are many coal mining in China has reached more than 1000 meters depth above, not only larger mining depth, but also the complicated geological structure, there exists the possibility of mine disaster,which brings very great difficulty in self drilling hollow bar coal mining support.

Although coal company invested a lot in roadway support,but there is still a big problem in roadway supporting technology .The main performance can be summarized as the following:

(1) Increasing with the depth of the mine and complexity of geological structure, make the tunnel pressure is greater and greater.

(2) The current engineering analogy method is still applied to guide all parameters of the roadway,which was not form a scientific and rigorous computer-aided dynamic and the rationality of support evaluation system to self drilling hollow bar support work, at the same time，also can't guarantee the best effect in roadway and coal mine safety and economic benefits.

(3)Rock fall net secondary supporting theory in the places such as soft rock fracture zone fails to affect deep in the dynamic pressure influence area, tectonic stress under special conditions, such as belt, soft rock broken belt , these still need further study.

(4) The current use of supporting materials widely adopted low bigger pitch, the clamping force of the self drilling hollow bar, and sustained after the great earthquake (such as: shooting) is easy to become loose, there are some other materials and equipment are not fit for the coal mine roadway condition, unable to meet the required supporting conditions.