Method for roadway driving along goaf under original roadway top plate of fully mechanized top coal caving goaf

Abstract

The invention discloses a method for roadway driving along a goaf under an original roadway top plate of a fully mechanized top coal caving goaf. An air return roadway of a lower section and a conveying roadway of an upper section are arranged on an identical position, when a first mining face is stoped, the top plate of the roadway and the coal wall of one side of entity coal are maintained through coal filling sacks to be free from the damage of movement of overlying rock, and maintain the relative integrity. Top coal on an end socket support on one side of the roadway goaf is lowered down, and serves as a coal edge of one side of the roadway goaf after grouting reinforcement. After the first mining face is excavated, the overlying rock is stable in movement, and the pressure of the surrounding rock of the roadway is released completely, tunneling is then carried out on the coal filling sacks and the plumped bottom plate of the roadway, and the fact that tunneling work is carried out in a pressure relieved area is guaranteed. Compared with the prior art, the method has the advantages of being safe, efficient, small in coal loss, low in cost and high in quality of roadway projects. The method for the roadway driving along the goaf under the original roadway top plate of the fully mechanized top coal caving goaf is researched and finished through a project with the number of 51374137 of the Natural Science Foundation of China.

Description

technical field [0001] The invention relates to a coal mining roadway excavation method in a coal mine. The specific method is to fill the transport roadway that enters the goaf when the working face of the upper section is mined, and after the movement of the overlying strata in the goaf in the upper section is stabilized, the The method of excavating the return air roadway in the lower section along the gob under the roof of the original transport roadway in the goaf of the upper section. Background technique [0002] At present, after the longwall working face of extra-thick coal seam is mined, there are three methods for the mining roadway along the goaf of the adjacent working face: retaining roadway along the goaf, driving along the goaf with narrow coal pillars and driving roadway with coal pillars. [0003] Gobside entry retention in the longwall working face of extra-thick coal seams requires the construction of a concrete wall on the goaf side of the entryw...

AI Technical Summary

Problems solved by technology

Disadvantages of this method: firstly, the amount of work is large, the labor intensity is high, and the cost is high; secondly, the lower end of the working face is a place with the busiest production, where the concrete wall is constructed, and the coal mining work will be seriously affected. It is difficult to organize regular circulation; thirdly, the concrete wall is quickly subjected to the motion load of the roof, and it is too late to reach the final setting strength. Once the strength limit is reached and damaged, the roof will hide a great hidden danger

Fourth, because the concrete wall is loaded earlier, the load cannot be transferred to the depth of the coal body of the adjacent working face, and the wall is required to have high strength. The phenomenon of top pressure and bottom drum affects the normal use function of the roadway

Fifth, artificial construction of concrete walls also increases mining costs

[0004] The return air roadway of the back-mining face is at the edge of the goaf of the first-mining face. The main disadvantages of the roadway excavation method with coal pillars are: first, when the size of the coal pillars is not selected, the roadway to be excavated may be in the goaf. within the support pressure range of the edge of the zone, resulting in serious deformation of the roadway, difficult maintenance, and even life-threatening rockburst

[0005] Leaving narrow and small coal pillars to excavate along the goaf Although theoretically speaking, the surrounding rock of the roadway is in the pressure relief zone, which avoids the influence of the peak bearing pressure, but the deformation of the roadway is serious, and the maintenance of the roadway is huge. High strength, low work efficiency

It is also very difficult to find the balance point between pressure relief and support on site. Not only that, but the solid coal side of the goaf roadway is also often threatened by the hidden danger of mine pressure

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