CN-122014283-A - Anti-shearing support system and method for soft mould gob-side entry retaining weak composite roof

CN122014283ACN 122014283 ACN122014283 ACN 122014283ACN-122014283-A

Abstract

The invention discloses a shearing-resistant support system for a soft composite roof of a soft mould gob-side entry retaining, which comprises an advanced working surface grouting support structure, a flexible net paved in front of an end support frame, a diamond-shaped metal net additionally arranged behind the end support frame, and a repairing anchor rod and a steel plate for fixing the diamond-shaped metal net and reinforcing a roof of a space to be poured. The shearing-resistant support system for the soft composite roof of the soft mould gob-side entry retaining solves the problem that the roof of the wall body of the gob-side entry retaining is prone to shearing under the disturbance of the mining stress of large mining height.

Inventors

Zou Yunxing
ZHOU JIALE
GAO SHENG
CAO XINYUN
FAN RUI
ZHANG WUTAO

Assignees

国能包头能源有限责任公司
国能包头能源有限责任公司万利一矿
陕西开拓新矿业工程有限公司

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (10)

1. The shearing-resistant support system for the soft composite roof of the soft mould gob-side entry retaining is characterized by comprising an advanced working surface grouting support structure, a flexible net paved in front of an end support frame, a diamond-shaped metal net additionally arranged behind the end support frame, and a repairing anchor rod and a steel plate for fixing the diamond-shaped metal net and reinforcing the roof of a space to be poured.
2. The shearing prevention support system for the soft composite roof of the soft mould gob-side entry retaining machine according to claim 1 is characterized in that the grouting support structure of the advanced working face adopts an anchor cable drilling machine to vertically drill hollow grouting anchor cables on the roof in the range of not less than 80m of the advanced working face.
3. The shearing prevention support system for the soft composite roof of the flexible mold gob-side entry retaining tunnel according to claim 2 is characterized in that the hollow grouting anchor cables are arranged in two rows along the longitudinal direction of the gob-side entry retaining tunnel, the distance between the first row and the primary recovery side is 600mm, the distance between the second row and the first row is 2000mm, the distance is 2000mm, the diameter of the hollow grouting anchor cable is 21.8mm, and the length is 9300mm.
4. The shearing prevention support system for the soft composite roof of the soft mould gob-side entry retaining is characterized in that the advanced working face grouting support structure is used for roof grouting reinforcement within the range of not less than 20m of the advanced working face.
5. The soft composite roof shear support system for the soft mold gob-side entry retaining according to claim 4, wherein the roof grouting material is silicate modified polyurethane material for coal mine reinforcement.
6. The shear-resistant support system for the soft composite roof of the gob-side entry retaining according to claim 5, wherein one side of the diamond-shaped metal net exceeds the goaf side of the soft concrete wall by 300-500mm, and the other side of the diamond-shaped metal net extends into the gob-side entry retaining roadway.
7. The shear-resistant support system for a soft mold gob-side entry retaining soft composite roof according to claim 6, wherein the repair anchor is a threaded steel anchor, and is installed along both sides of the soft mold concrete wall.
8. The shearing prevention support method for the soft composite roof of the soft mould gob-side entry retaining is characterized by comprising the following steps of; step 1, grouting holes are drilled on an advanced working surface, and hollow grouting anchor cables are installed; step 2, grouting and reinforcing the top plate of the retaining roadway by using a hollow grouting anchor cable along with the exploitation of the working face; Step 3, along with pushing and picking of the working face, paving a flexible net in front of the end support frame; step 4, paving a diamond-shaped metal net below the flexible net; step 5, paving a diamond-shaped metal net, then repairing and punching anchor rod holes, installing repairing and punching anchor rods in the repairing and punching anchor rod holes, and supporting a steel plate by using an anchor rod tray; Step 6, pouring concrete after the flexible mold is hung by the mold hanging device, and demolding by the mold hanging device and moving forward along with the working surface; And 7, repeating the steps 1-6 until the whole working face entry retaining is completed.
9. The shearing prevention support method for the soft composite roof of the flexible mold gob-side entry retaining according to claim 8 is characterized in that in the step 1, in order to prevent shearing action of a flexible mold concrete wall on the roof in the gob-side entry retaining roadway, a leading working face is not less than 80m, namely, a hollow grouting anchor cable is arranged in a hollow grouting anchor cable arranging area perpendicular to the roof by adopting an anchor cable drilling machine, two rows of hollow grouting anchor cables are arranged along the longitudinal direction of the gob-side entry retaining roadway, the distance between the first row of hollow grouting anchor cables and a primary recovery side is 500-700mm, the distance between the second row of hollow grouting anchor cables and the secondary recovery side is 2600-3000mm, the row distance between the two rows of hollow grouting anchor cables is 1800-2200mm, and the distance between adjacent hollow grouting anchor cables in the same row is 1800-2200mm.
10. The shearing prevention support system for the soft composite roof of the soft mold gob-side entry retaining system according to claim 9, wherein in the step 2, the grouting material is silicate modified polyurethane material for reinforcing coal rock of a coal mine, the grouting pressure is not lower than 3MPa, the slurry wraps the anchor cable and fills the cracks of the roof strata, and the roof is formed into a stable structure.

Description

Anti-shearing support system and method for soft mould gob-side entry retaining weak composite roof Technical Field The invention belongs to the technical field of coal mine gob-side entry retaining support, and particularly relates to a shearing-resistant support system for a soft mold gob-side entry retaining weak composite roof and a shearing-resistant support method for the soft mold gob-side entry retaining weak composite roof. Background The large mining height fully-mechanized mining technology has become one of core technologies for high-efficiency development of thick coal seams because of the advantages of improving the stoping efficiency, reducing the tunneling quantity of a roadway, reducing the tunneling rate of ten thousand tons and the like. The gob-side entry retaining is used as a key technical means of a large mining height working face, and the transportation gate (or return air gate) of the previous working face is reserved as a stoping tunnel of the next working face, so that tunneling of the tunnel can be reduced, resource recovery rate is improved, mining connection tension problem is effectively relieved, and the gob-side entry retaining is an important supporting technology for green mining and intelligent transformation of coal mines. However, under large mining conditions, the basic roof period running step distance and dynamic load coefficient are obviously increased, and for the characteristic of 'weak composite roof', the roof consists of multiple layers of weak cemented and low-strength rock strata such as mudstone, sandy mudstone, thin limestone and the like, and the laminated fissures develop, the overall integrity is poor, and the self-stabilization capability is weak. The roof is easy to shear under the disturbance of the mining stress of the large mining height, and restricts the popularization and application of the gob-side entry retaining technology of the large mining height. Therefore, aiming at the problem that the gob-side entry retaining working face weak composite roof shears the roof of the entry retaining wall body, a novel supporting method is provided, the anchoring accurate shearing prevention design is realized, the transverse cooperative force transmission is formed into an integral shearing prevention layer, the asymmetric pressure is adapted, and the shearing prevention capability of the roof is fundamentally improved. Disclosure of Invention The invention provides a soft composite roof shearing prevention support system for a soft mould gob-side entry retaining, which solves the problem that a roof of a wall body of a gob-side entry retaining is prone to shearing under the disturbance of large mining height mining stress. In order to achieve the aim, the technical scheme adopted by the invention is that the shearing-resistant support system for the soft composite roof of the soft mould gob-side entry retaining comprises an advanced working surface grouting support structure, a flexible net paved in front of an end support frame, a diamond-shaped metal net additionally arranged behind the end support frame, and a repairing anchor rod and a steel plate for fixing the diamond-shaped metal net and reinforcing the roof of a space to be poured. The technical scheme of the invention also has the following characteristics: the grouting support structure of the advanced working face adopts an anchor cable drilling machine to lay a hollow grouting anchor cable perpendicular to the top plate in the range of the advanced working face of not less than 80 m. The hollow grouting anchor cable is arranged in two rows along the longitudinal direction of the roadway, the distance between the first row and the primary extraction side is 550-650mm, the distance between the second row and the first row is 1800-2200mm, and the distance between the second row and the first row is 1800-2200mm. The advanced working face grouting support structure performs top plate grouting reinforcement within the range of not less than 20m of the advanced working face. The top plate grouting material is silicate modified polyurethane material for reinforcing coal rock of coal mine. One side of the diamond-shaped metal net exceeds 300-500mm of the goaf side of the soft mold concrete wall, and the other side of the diamond-shaped metal net extends into the roadway. The repairing anchor rod is made of screw steel anchor rods and is arranged along two sides of the flexible concrete wall. The second purpose of the invention is to provide the shearing-resistant supporting method for the soft composite roof of the soft mould gob-side entry retaining, which ensures the stability of surrounding rock of the working space during the entry retaining and ensures the safety of constructors of the working space. In order to achieve the aim, the technical scheme adopted by the invention is that the shearing prevention support method for the soft composite roof of the soft mould gob-side entry retaining compri