CN-121976802-A - Special triangular coal pillar drilling pressure relief method

CN121976802ACN 121976802 ACN121976802 ACN 121976802ACN-121976802-A

Abstract

The invention relates to a drilling pressure relief method for a special triangular coal pillar, which comprises the steps of obtaining a stress concentration coefficient and a roadway deformation rate of the triangular coal pillar, determining a stress concentration area, implementing drilling pressure relief in a roadway of the stress concentration area when the stress concentration coefficient exceeds a first set threshold value and the roadway deformation rate exceeds a second set threshold value, monitoring stress and displacement deformation in the roadway to obtain monitoring data, judging a pressure relief state according to the monitoring data, and dynamically adjusting drilling parameters if the monitoring data exceeds a safety threshold value. According to the invention, through adjusting proper drilling parameters, the pressure relief area precisely acts on the high-stress concentrated zone at the edge of the coal pillar, so that the formation of a crossed secondary pressure relief area in the center of the coal pillar is effectively avoided, and the problems of pressure relief failure or surrounding rock deformation aggravation caused by unreasonable hole depth design in the prior art are solved.

Inventors

ZHANG JIPING
ZENG QINGLU
LI XIAOHAO
ZHANG YIN
WEI XIAOTAO
SHAO MINGMING
LIU WEI
YANG JIHUI

Assignees

新疆工业学院

Dates

Publication Date: 20260505
Application Date: 20260326

Claims (9)

1. The special triangular coal pillar drilling pressure relief method is characterized by comprising the following steps of: s1, acquiring a stress concentration coefficient and a roadway deformation rate of a triangular coal pillar, and determining a stress concentration area; S2, when the stress concentration coefficient exceeds a first set threshold value and the roadway deformation rate exceeds a second set threshold value, drilling pressure relief is implemented in the roadway of the stress concentration area; s3, monitoring stress and displacement deformation in the roadway to obtain monitoring data; and S4, judging a pressure relief state according to the monitoring data, and dynamically adjusting the parameters of the drilling if the monitoring data exceeds a safety threshold.
2. The method of claim 2, wherein if the monitored data does not exceed the safety threshold, the pressure relief is satisfactory.
3. The method for pressure relief of a special triangular coal pillar borehole according to claim 1 or 2, wherein the dynamic adjustment comprises at least one of narrowing the borehole spacing or supplementing the number of boreholes in the stress concentration area, and flushing the borehole that is clogged.
4. A special triangular coal pillar drilling pressure relief method as claimed in claim 3, wherein in step S2, the first set threshold is 1.5 and the second set threshold is 2.
5. The special triangular coal pillar drilling pressure relief method according to claim 4, wherein the monitoring data comprises a top plate vertical displacement amount, a bottom plate vertical displacement amount and two-side vertical stress, the safety threshold comprises a top plate vertical displacement amount threshold, a bottom plate vertical displacement amount threshold and a two-side vertical stress threshold, and the parameter of the drilling is dynamically adjusted when the top plate vertical displacement amount is larger than the top plate vertical displacement amount threshold, the bottom plate vertical displacement amount is larger than the bottom plate vertical displacement amount threshold, and the two-side vertical stress is larger than the two-side vertical stress threshold.
6. The special triangular coal pillar drilling pressure relief method according to claim 5, wherein the pressure relief is satisfactory when the top plate vertical displacement is smaller than or equal to a top plate vertical displacement threshold, the bottom plate vertical displacement is smaller than or equal to a bottom plate vertical displacement threshold, and the two-side vertical stress is smaller than or equal to a two-side vertical stress threshold.
7. The method according to claim 6, wherein in the step S2, the drilling parameters include drilling depth, drilling diameter, adjacent drilling interval and drilling arrangement mode, wherein the drilling depth is 28-32m, the drilling diameter is 100-200mm, the adjacent drilling interval is 5-8m, the drilling arrangement mode is that drilling is constructed from adjacent roadway to the interior of coal pillar, and the included angle between the drilling axis and the roadway wall is 30-45 °.
8. The special triangular coal pillar drilling pressure relief method according to claim 7, wherein the top plate vertical displacement threshold is 115mm, the bottom plate vertical displacement threshold is 4mm, and the two-side vertical stress threshold is 21Mpa.
9. The pressure relief method for drilling of the special triangular coal pillar, according to claim 8, wherein in the drilling construction, the verticality deviation of the drilling is +/-2 degrees, and high-pressure air is adopted to continuously clean the hole wall during drilling.

Description

Special triangular coal pillar drilling pressure relief method Technical Field The invention relates to the technical field of coal mining safety, in particular to a special triangular coal pillar drilling pressure relief method. Background As the depth of coal mining continues to increase, vertical stress on two sides is obviously increased, deformation instability of surrounding rock is more common, and excessive deformation caused by high ground stress is difficult to effectively control by conventional supporting technology. The triangular coal pillar is used as a common residual coal body shape in the coal mining process, is easily influenced by mining of a working face to form a high-stress concentration area, gathers a large amount of elastic energy, is extremely easy to induce rock burst, and further causes safety accidents such as roadway deformation, coal body gushing and support failure, so that the coal mining safety is seriously threatened, and the risk of rock burst can be eliminated by pressure relief of the triangular coal pillar. The drilling pressure relief method has the advantages of convenience in construction, small workload, no influence on the construction period and the like, and is widely applied to rock burst prevention and control. According to the method, drilling is constructed in the coal body, the elastic energy accumulated by the coal body is released, and high stress is transferred, so that the purposes of pressure relief and impact prevention are achieved. However, the existing drilling pressure relief scheme is not designed accurately aiming at the special geometric form and stress distribution rule of the triangular coal pillar, and has the core defects that the drilling depth is unreasonable, if the hole depth is too large, a crossed secondary pressure relief area is formed in the center of the coal pillar, so that the bearing capacity of a coal body is reduced, high stress is transferred to the edge of the coal pillar, the vertical stress and displacement deformation of two sides of a roadway are instead aggravated, the rock burst risk is increased, and if the hole depth is too small, the high stress cannot be transferred effectively, the elastic energy is released insufficiently, the pressure relief effect is poor, and the requirement for preventing and controlling the rock burst is difficult to be achieved. The defects directly lead to the pressure relief failure of the existing scheme, even aggravate surrounding rock deformation, and can not adapt to the pressure relief requirement of a special triangular coal pillar. Disclosure of Invention In order to solve the technical problems, the invention aims to provide the special triangular coal pillar drilling pressure relief method, which realizes accurate and efficient pressure relief of the special triangular coal pillar by dynamically adjusting drilling parameters after monitoring the pressure relief effect. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: A special triangular coal pillar drilling pressure relief method comprises the following steps: s1, acquiring a stress concentration coefficient and a roadway deformation rate of a triangular coal pillar, and determining a stress concentration area; S2, when the stress concentration coefficient exceeds a first set threshold value and the roadway deformation rate exceeds a second set threshold value, drilling pressure relief is implemented in the roadway of the stress concentration area; s3, monitoring stress and displacement deformation in the roadway to obtain monitoring data; and S4, judging a pressure relief state according to the monitoring data, and dynamically adjusting the parameters of the drilling if the monitoring data exceeds a safety threshold. Further, if the monitored data does not exceed the safety threshold, the pressure relief meets the requirement. Further, the interval between the drilling holes is reduced or the number of the drilling holes is increased in the stress concentration area, and the drilling holes with the blocking are washed. Further, in step S2, the first set threshold is 1.5, and the second set threshold is 2. Further, the monitoring data comprises a top plate vertical displacement amount, a bottom plate vertical displacement amount and two sides of vertical stress, the safety threshold comprises a top plate vertical displacement amount threshold, a bottom plate vertical displacement amount threshold and two sides of vertical stress threshold, the top plate vertical displacement amount is larger than the top plate vertical displacement amount threshold, the bottom plate vertical displacement amount is larger than the bottom plate vertical displacement amount threshold, and when the two sides of vertical stress is larger than the two sides of vertical stress threshold, the parameters of the drilling hole are dynamically adjusted. Further, when the vertical displacement of the top p