A method of improving the performance of strip coal pillars by using grouting joint support bolts

Abstract

The invention discloses a method for improving the performance of striped coal pillars by using grouting combined support bolts, relates to the technical field of strip coal pillar mining, designs the structure of grouting combined support bolts, and uses grouting combined support The method of improving the performance of the strip coal pillar by the protective bolt realizes the dual functions of grouting in the yield zone of the strip coal pillar and bolt support in the yield zone and elastic zone of the strip coal pillar. On the one hand, the bearing capacity of the yield zone is improved, and on the other hand On the one hand, the grouting combined with the supporting bolts gives the coal pillar a certain lateral restraint force, and the coal pillar is transformed from a two-way stress state to a three-way stress state, and the strength and performance of the coal pillar are improved; The top and bottom of the grouting combined support bolts are obliquely drilled. After grouting, the coal pillar is connected with the roof and the floor as a whole, which limits the lateral deformation of the coal pillar. The structure of the grouting combined support bolt is simple and can be The column width adjusts the length of the hollow grouting bolt body, which is easy to install, ensures the improvement of the bearing capacity in the yield zone, and is low in cost. It is suitable for large-scale promotion and application in mining areas.

Description

technical field [0001] The invention relates to the technical field of strip coal pillar mining, in particular to a method for improving the performance of strip coal pillars by using grouting joint support bolts. Background technique [0002] The strip coal pillar mining method is widely used in the "three-down" coal mining. After the mining of the working face, the yield zone and elastic zone begin to form from the edge of the coal pillar, and the yield zone gradually Destruction forms and expands the broken zone, which will eventually lead to the instability of the coal pillar, resulting in surface subsidence, and causing huge damage. The traditional reinforcement methods for wide coal pillars include bolt reinforcement, grouting reinforcement, anchor cable reinforcement, anchor mesh support, etc., but they all have certain disadvantages. The length of the anchor rod is the key factor restricting the reinforcement of wide coal pillars with anchor rods; Grouting support i...

AI Technical Summary

Problems solved by technology

[0002] The strip coal pillar mining method is widely used in the "three-down" coal mining. After the mining of the working face, the yield zone and elastic zone begin to form from the edge of the coal pillar, and the yield zone gradually The damage forms a broken zone and expands, which will eventually lead to the instability of the coal pillar, causing the surface to subside, and causing huge damage

The traditional reinforcement methods for wide coal pillars include bolt reinforcement, grouting reinforcement, anchor cable reinforcement, anchor mesh support, etc., but they all have certain disadvantages. The length of the anchor rod is the key factor restricting the reinforcement of wide coal pillars with anchor rods; Grouting support improves the bearing capacity of the yield zone, but it cannot provide effective lateral restraint for the coal pillar and cannot limit the development of the yield zone of the coal pillar; the anchor cable support cannot adapt to the large deformation of the coal pillar and fails, and the anchor net Support also cannot restrict the development of the yield zone of the coal pillar

Images