Coal pillar-free excavation method for 'three-under' pressed coal

Abstract

The invention discloses a coal pillar-free excavation method for 'three-under' pressed coal. The method comprises the following steps that: each filling section main roadway comprises an auxiliary transportation main roadway, a rubber transportation main roadway and an air return main roadway, and a filling section is arranged around each filling section main roadway; each filling section is divided into a plurality of filling working faces, and a crossheading tunneling working face is reserved between every two adjacent filling working faces; and tunneling of a rubber transportation crossheading and tunneling of an auxiliary transportation crossheading are sequentially and alternately carried out on the crossheading tunneling working faces, the filling working faces which are adjacent and are excavated in the same direction and the rubber transportation crossheading are operated in parallel, and the filling working faces which are adjacent and are excavated in the same direction and the auxiliary transportation crossheading are operated in parallel. The method has the advantages that the application conditions of the patent technology are relatively loose; the method has universal applicability, and can be used for mining thin coal seams, medium-thickness coal seams and thick coal seams; and no rigid requirement is needed for lithology of top and bottom plates of the coal seams; the method can be used for excavation operation of 'three-under' pressed coal, and can also be used for excavation operation of mining areas, coal pillar recovery of mine mining areas and the like.

Description

Technical field: [0001] The invention relates to the technical field of coal mining, in particular to a "three-down" coal-pillar-free mining method. Background technique: [0002] "Three-down" pressed coal refers to the pressed coal under the railway, under the water body and under the building. The filling mining technology is of great significance to the mining of the "three-down" pressed coal. At present, coal mine filling mining in my country usually adopts no coal pillar mining, and then uses The paste filling process is used to fill the goaf. This mining and filling process has achieved good results in the field, and has played a certain role in solving the problems of "three downs" coal pressing and surface subsidence control; [0003] Among them, there are two main mining techniques without coal pillars: 1. Roof cutting method: fill a certain distance from the coal wall of the working face in advance, and drill deep into the roof in advance in the roadway of the rubbe...

AI Technical Summary

Problems solved by technology

[0004] The coal pillarless mining technology using the above two methods has the following problems: first, the mining dynamic pressure is strong during the recovery of the above two methods, and there are high requirements for the lithology of the coal seam roof and floor; The influence of coal seams is smaller than that of thick coal seams, and it is mostly used for mining medium-thick coal seams, not suitable for thick coal seams; in addition, the above two methods are suitable for coal seams with good and stable roof and floor lithology. Therefore, the above two methods are applicable The conditions are relatively harsh and the universal applicability is poor. Second, in the above two methods, after the fully-mechanized mining face on the side of the rubber transportation channel is recovered, due to the influence of mining dynamic pressure, it is necessary to strengthen the support of the rubber transportation channel. for maintenance, and the reserved rubber transportation chute needs to be used as the return air chute of the adjacent next fully mechanized mining face, and will still be affected by the mining dynamic pressure when mining the next fully mechanized mining face; therefore , the requirements for the support strength of the rubber transport along the trough are very high, and the requirements for the selection of roof support materials are higher, resulting in very high support costs and labor intensity; The side coal body close to the goaf is mined, and the reserved space is separated from the goaf by using the cast-in-place concrete wall, and the roadway is reserved along the goaf; however, due to the slow progress of the fully mechanized mining face After the coal is mined out, it will take 3-6 months or longer for the rock formation above the goaf to gradually stabilize. During this period, the concrete wall has to bear the pressure of the roof and The influence of the dynamic pressure of the fully mechanized mining face will greatly affect the bearing effect of the cast-in-situ concrete wall; fourth, after the roadway is left along the goaf, the isolation formed by the direct roof of the goaf needs to be reinforced by spraying. The roadway roof isolated by sealing the gap still needs secondary support for maintenance, which complicates the on-site operation process and greatly increases the labor intensity; seriously affects the advancing speed of the fully mechanized mining face, and has a great impact on the comprehensive mining face The impact of normal production organization is very obvious; fifth, after the roadway is left along the goaf, the surrounding rock deformation is obvious, and the maintenance cost of the roadway in the later period is relatively high. After entering the impact range of the advanced pressure of the filling working face, the required strengthening support strength is higher; Sixth, with the continuous advancement of the fully mechanized mining face, in these two pillarless mining technologies, the isolation formed by the direct roof and the cast-in-place concrete wall are continuously affected by the mining dynamic pressure, and the isolation formed by the roof connection There are still cracks between them. During the solidification period, the cast-in-place concrete wall is also affected by the dynamic pressure of mining, resulting in poor integrity, many cracks and small width; the ability to prevent air leakage in the goaf and natural fire in the goaf is relatively poor, and it is also It is not conducive to the isolation of accumulated water in the goaf, resulting in a relatively poor mining operation environment in the fully mechanized mining face

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