Parallel digging, mining and filling operation coal mining method for controlling overlaying strata fracture and surface subsidence

Abstract

Disclosed is a parallel digging, mining and filling operation coal mining method, in which a stope haulage roadway, stope branch roadways, and two-winged adits are arranged in a stope. The stope haulage roadway and the stope branch roadways serve as haulage passages, and coal mining work is carried out in the two-winged adits. All two-winged adits are mined sequentially and filled timely, and coal mass that has not been mined or two-winged adits that have been filled always exist at the two sides of the two-winged adit that are being mined, to support and control the roof. The two-winged adits can be mined without support or with less supports by controlling the length of the two-winged adits and the number of two-winged adits filled in one time, whereupon pillar-free mining can be realized.

1 . A coal mining method for controlling overlaying strata fracture and surface subsidence, comprising the following steps:
 a. arranging a stope haulage roadway along an edge part or middle part of a stope, and digging a stope branch roadway perpendicularly or obliquely to the stope haulage roadway;   b. performing multiple two-winged adits mining in a coal mass in the stope branch roadway from inner side to outer side, wherein, each two-winged adit and the corresponding section of the stope branch roadway is referred to as a stage;   c. performing next stage two-winged adit mining at an interval equal to a width of a two-winged adit along the stope branch roadway, whenever each stage two-winged mining adit mining is completed;   d. building up sealing walls in the stope branch roadway and filling the two-winged adits that have been mined and the corresponding sections of the stope branch roadway, after multiple stages two-winged adits mining is completed;   e. repeating steps b and c to continue two-winged adits mining in the stope branch roadway, while executing step the steps d;   f. repeating the steps b, c, d, and e, until all two-winged adits in the stope branch roadway have been mined and filled;   g. digging a next stope branch roadway parallel to the stope branch roadway at one side of the stope branch roadway, while mining and filling the two-winged adits in the stope branch roadway;   h. repeating the steps b, c, d, e, and f, until the next stope branch roadway and all two-winged mining adits in it have been mined and filled;   i. repeating the steps b, c, d, e, f, and g, until all stope branch roadways and all two-winged adits therein at one side of the stope haulage roadway have been mined and filled;   j. digging a stope haulage roadway on the other side of the stope and digging a stope branch roadway at one side of the stope haulage roadway, while mining and filling the stope branch roadway and the two-winged adits at one side of the stope haulage roadway, wherein, the stope branch roadway is located between two adjacent stope branch roadway; and   k. performing two-winged adits mining and filling in the stope branch roadway by repeating steps b, c, d, e, f, and g, until the coal resource in the entire stope has been mined out and filled.   
     
     
         2 . The method according to  claim 1 , wherein: an included angle α between the direction perpendicular to the stope branch roadway and the adit is determined according to a requirement of the working angle of the coal mining equipment. 
     
     
         3 . The method according to  claim 1 , wherein: a width of each two-winged adit is substantially equal to a working width of a coal mining equipment. 
     
     
         4 . The method according to  claim 1 , wherein: distance L between adjacent stope branch roadways at the same side of the stope haulage roadway is determined by the formula L≈L 1 +2L 2   cosα , where, L 1  is a width of a stope branch roadway, and L 2  is a length of an adit.