Caving control method for fully mechanized mining face tip mining road way top plate

Abstract

The invention discloses a caving control method for a fully mechanized mining face tip mining road way top plate, which comprises the following steps of: drilling a hole on a fully mechanized mining face tip worked-out side mining road way top plate; if the inside of a bore has a good integrality and a bore wall is free from cracks, installing a sealing device on a position which is 0.5m far away from a bore mouth in the bore; if the inside of the bore has a poor integrality and the bore wall is provided with an obvious crack which affects grouting effect, firstly installing a flexible plastic sleeve in the bore, and installing a bore sealing device on a position which is 0.5m far away from the bore mouth in the plastic sleeve; injecting the prepared expanded slurry into the bore or the plastic sleeve in the bore through the bore sealing device; and bursting the bore wall by static force generated by the expansion of expanding agent. Therefore the integrality of a coal-rock mass is damaged to lose stability, so that the drilled top plate arranged on a fully mechanized mining face tip mining road way loses stability to realize a purpose of manually controlling top plate caving. With the method, the problems that the mining road way top plate cannot cave in time along with mining face propelling, bracket pressure is increased due to overlarge tip hanging arch, gas is accumulated and the like are solved, and the caving of the fully mechanized mining face tip mining road way top plate is effectively controlled.

Description

technical field [0001] The invention relates to a method for caving the top coal of the goaf of the back mining roadway at the end of a fully mechanized mining face, in particular to a method for controlling the caving of the top coal in the gob area of ​​the back mining roadway of the fully mechanized mining working face and the initial mining top coal of the cut hole The roofing method is applicable to the situation where the roof of the roadway within the goaf does not collapse in time during the mining process of the working face, resulting in a large area of ​​suspended roof. Background technique [0002] In the fully mechanized mining face, the support method of anchor rod + anchor cable + metal mesh is adopted for the mining roadway and the open cut eye, and the support effect is good. After the start of initial mining, due to the influence of various factors on the anchorage of most anchor cables during the service period, it is difficult to withdraw the anchor, so t...

AI Technical Summary

Problems solved by technology

[0007] The deficiencies of the above-mentioned prior art are: ① The method of water injection and pre-blasting the roof in the advanced working face is a rough roof control method. The roof is weakened by pre-blasting and water injection. However, the accurate prediction and control of roof pressure steps, time, strength, etc. on the working face cannot be realized; ②The method of water injection and pre-blasting is used to control the roof slump, and no reasonable method can be found. Compared with the caving workload, it is difficult to minimize the caving workload and optimize the method, and there are defects in the design, such as the lack of scientific and reasonable calculation methods when designing the caving height and caving step distance

If the depth of the groove is too shallow, the designed roofing effect cannot be achieved; if the depth of the groove is too large, the engineering volume of roof management will be large; ③ During the process of treating the roof with pre-blasting method, toxic gases such as CO will be produced, seriously Pollution of the working face environment, coupled with the blasting itself has certain risks, cannot guarantee the safe production of the working face; especially in the case of high-gas mines or when the gas content of the mining roadway at the end working face exceeds the standard, the blasting method is used to treat the roof, which is very easy to cause Gas explosion; ④ The method of treating the roof of the goaf by the induced caving method, mining the edge ore body and the support inside the caving goaf, although it can also play a role in controlling the roof caving, but in the process of mining and caving, there are Many uncertain safety factors make it difficult to achieve safe production at the working face, and this method is mainly applicable to metal mines; ⑤ With the existing grouting (expansion agent) technology, due to the existence of hole wall cracks, the expansion agent will pass through during the grouting process. The cracks in the hole wall flow to the surrounding of the hole wall, and sometimes the expansion agent flows into the anchor rod or the anchor cable hole, so that the grouting hole, the hole wall crack, the anchor rod, and the anchor cable hole will form a through system, and the expansion agent flows into these through holes. When the system is installed, the expansion agent in the drill hole is lost, and the effect of expansion and extrusion cannot be realized, resulting in a lot of waste and increasing the management cost of the roof

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