CN110685688B - Coal mine surrounding rock control method based on chemical modification - Google Patents
Coal mine surrounding rock control method based on chemical modification Download PDFInfo
- Publication number
- CN110685688B CN110685688B CN201910922990.7A CN201910922990A CN110685688B CN 110685688 B CN110685688 B CN 110685688B CN 201910922990 A CN201910922990 A CN 201910922990A CN 110685688 B CN110685688 B CN 110685688B
- Authority
- CN
- China
- Prior art keywords
- rock
- coal mine
- holes
- surrounding
- hard
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C41/00—Methods of underground or surface mining; Layouts therefor
- E21C41/16—Methods of underground mining; Layouts therefor
- E21C41/18—Methods of underground mining; Layouts therefor for brown or hard coal
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C39/00—Devices for testing in situ the hardness or other properties of minerals, e.g. for giving information as to the selection of suitable mining tools
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
Abstract
The invention discloses a coal mine surrounding rock control method based on chemical modification, which comprises the steps of firstly drilling a rock mass (a hard rock stratum or a broken surrounding rock) to be modified, and then further injecting a chemical reagent (a softening agent or a combination of hydrochloric acid and sodium carbonate) into the drilled hole, so that the hardness and integrity of the rock mass are changed, the rock mass is weakened or hardened, a large-area suspended ceiling is prevented from being formed behind a working face of the hard rock stratum, the initial pressure step distance and the periodic pressure step distance are reduced, the air impact and roof impact accidents caused by the instant falling of the hard roof behind the working face are avoided, the problems of energy release and stress transfer of a roadway roof, the hard roofs of coal seams needing to be weakened near other roadways and the like are solved, and the problems of loosening and reinforcing the broken surrounding rock mass are solved, so that the subsequent safe mining of the coal roadway is effectively ensured. In addition, the method is simple, low in cost, convenient to use and wide in practicability.
Description
Technical Field
The invention relates to a coal mine surrounding rock control method, in particular to a coal mine surrounding rock control method based on chemical modification.
Background
During coal mining, when the roof above the coal seam has good integrity, strong self-stability capability, high strength and no joint crack structure is developed, the initial pressure step and the periodic pressure step are increased, so that a large area of suspended roof is generated above the goaf. The roof under this condition can form air impact and roof impact when falling suddenly, makes personnel, mechanical equipment etc. in the pit form very big potential safety hazard. The 1/3 coal mine in China belongs to a hard roof coal seam at present, in order to ensure safe and efficient production of coal, the area of roof overhanging leakage must be reduced, large-area pressure of a roof is prevented, in order to improve the recovery rate of coal resources, pillar-free mining technologies such as gob-side entry retaining, roof cutting pressure relief automatic entry forming and the like are developed rapidly, and one of key points and difficulties of the technologies is roof weakening. At present, three methods are mainly used for weakening a hard roof of a coal mine, namely a blasting method for weakening the integrity of the roof by a designed blasting method; adopting high-pressure water injection to fracture the hard top plate so as to expand cracks in the rock mass and increase a hydraulic fracturing method of a weak surface in the rock mass; a gas-phase fracturing method of pushing the gas-phase fracturing device into the top plate drill hole to perform presplitting blasting to weaken the top plate; and a comprehensive weakening method combining the three methods and comprehensively applying the three methods.
The top plate weakening method has limitations, and the blasting method has the problems of potential safety hazards caused by blasting and limited top plate pre-splitting range; the hydraulic fracturing method is not suitable for hard rock layers with claystone, mudstone and shale interlayers and areas with geological destruction zones, and a large amount of water resources are consumed; the gas-phase fracturing method has the problems of relatively complex process and relatively high economic cost; the traditional reinforcement method not only consumes a large amount of manpower and material resources, but also has a weak and lasting reinforcement effect.
In addition, after the tunnel is tunneled, the surrounding rock stress around the tunnel is redistributed, and due to the influence of geological structures such as faults and the like, the surrounding rock of the tunnel is broken and loosened, the bearing capacity is reduced, roof caving is caused, and great potential safety hazards are caused to underground safe mining. According to relevant statistics, roof caving is the most common accident during mining work, accounting for about 40% of the accidents under the mining well, so that the broken soft roadway surrounding rock body must be reinforced. The traditional reinforcing method comprises the modes of anchor rod reinforcement, additional spraying, metal bracket erection, grouting and the like. The methods not only have higher construction difficulty, but also have poorer effect.
Therefore, a safer, more efficient and lower-cost control method for modifying the surrounding rock mass of the coal mine needs to be researched, so that the method not only can effectively weaken the top plate of the coal roadway, but also can reinforce the soft surrounding rock around the roadway.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a coal mine surrounding rock control method based on chemical modification, which can weaken a hard rock stratum and reinforce a broken surrounding rock, thereby ensuring the safe mining of a coal roadway.
In order to achieve the purpose, the invention adopts the technical scheme that: a coal mine surrounding rock control method based on chemical modification comprises the following specific steps:
A. after the tunnel is tunneled, carrying out hardness detection on a hard rock layer above the tunnel, if the coefficient of the Pouler hardness of the hard rock layer exceeds 8, entering the step B, and if not, entering the step D;
B. constructing multiple rows of weakened drill holes in the inner wall of the roadway towards a hard rock stratum, wherein the row spacing between adjacent rows is 1-10 m; the distance between adjacent weakening drill holes in each row is 0.5-5 m;
C. sequentially injecting a softening agent into each weakened borehole by using a retreating type grouting method and under the hydrostatic pressure of more than 2.5, sealing the holes for 1 hour, fully reacting the softening agent with the hard rock stratum, and then repeatedly injecting the softening agent and sealing the holes until the common hardness coefficient of the hard rock stratum is reduced to 3;
D. c, performing hardness detection on surrounding rocks around the roadway, entering the step E if the Pythiis hardness coefficient of the surrounding rocks is smaller than 1, and otherwise, completing the control process of the surrounding rocks of the coal mine;
E. constructing multiple rows of reinforcing drill holes in surrounding rocks on two sides of the inner wall of the roadway, wherein the row spacing between adjacent rows is 1-10 m; the distance between adjacent reinforced drill holes in each row is 0.5-5 m;
F. sequentially injecting hydrochloric acid into each reinforced drill hole by using a retreating type grouting method and sealing the holes by using more than 2.5 hydrostatic pressures so as to enable the hydrochloric acid to fully react with broken cementing substances (carbonate and sulfate) in the surrounding rock to generate corresponding chlorides, injecting sodium carbonate into each reinforced drill hole again and sealing the holes after 1 hour of sealing the holes, wherein the sodium carbonate can neutralize the redundant hydrochloric acid added for the first time and then react with various chlorides to generate corresponding carbonate precipitation cement so as to enable the micro precipitation cement in the broken rock to be converted into a strong cementing substance; repeating the steps until the Pythiier hardness coefficient of the surrounding rock reaches 5; and finishing the control process of the coal mine surrounding rock.
Furthermore, the diameter of the weakening drill hole and the diameter of the reinforcing drill hole are both in the range of 50 mm-100 mm. A drilling diameter within this range is most suitable, and if the drilling diameter is too large, construction is inconvenient and softener or hardener is wasted; if the bore hole diameter is too small this may result in a reduced contact surface for the softening or hardening agent to react with the rock components in the hard rock formation or surrounding rock, thereby increasing the time of the process.
Further, the weakened borehole terminates at 1/2 thickness of the hard rock formation; the ends of the reinforcement boreholes are at the 1/2 thickness of the surrounding rock. The arrangement of the position can increase the contact surface of the injected softening agent or hardening agent and rock components in the hard rock layer or the surrounding rock, thereby fully ensuring the chemical reaction of the injected softening agent or hardening agent and finally realizing the weakening of the hard rock layer and the strengthening of the surrounding rock.
Furthermore, the softening agent is concentrated phosphoric acid with the concentration of 80%, and the softening agent can react with silicon dioxide and calcium carbonate in the rock to generate corresponding salt and water after being injected into the hard rock stratum, so that the ordinary hardness coefficient of the hard rock is reduced, and the purpose of softening the hard rock stratum is achieved.
Compared with the prior art, the rock mass (hard rock stratum or broken surrounding rock) to be modified is subjected to drilling construction, and then a chemical reagent (softening agent or hydrochloric acid and sodium carbonate are combined) is further injected into the drilled hole, so that the hardness and integrity of the rock mass are changed, the rock mass is weakened or hardened, a large-area suspended ceiling is prevented from being formed behind a working face of the hard rock stratum, and the primary pressure step and the periodic pressure step are reduced, so that the air impact and roof impact accidents caused by instant falling of the hard roof behind the working face are avoided, the problems of energy release, stress transfer, other coal seam hard roofs needing to be weakened near roadways and the like of the roadway roof accumulation are solved, and the problems of loosening and broken surrounding rock body reinforcement are solved, so that the subsequent safe mining of the coal roadway is effectively guaranteed. In addition, the method is simple, low in cost, convenient to use and wide in practicability.
Drawings
FIG. 1 is a schematic representation of a borehole for weakening hard rock formations in accordance with the present invention;
FIG. 2 is a schematic illustration of a borehole for reinforcing surrounding rock in accordance with the present invention;
fig. 3 is a schematic plan view of the reinforced borehole of fig. 2 in the inner wall of the roadway.
In the figure: 1. coal seam, 2, roadway, 3, weakening drill hole, 4, hard rock stratum, 5, reinforcing drill hole, 6 and surrounding rock.
Detailed Description
The present invention will be further explained below.
As shown in the figure, the method comprises the following specific steps:
A. after the roadway 2 is tunneled, carrying out hardness detection on the hard rock stratum 4 above the roadway 2, if the coefficient of Pocken's hardness of the hard rock stratum 4 exceeds 8, entering the step B, and if not, entering the step D;
B. constructing a plurality of rows of weakened drill holes 3 towards a hard rock stratum 4 on the inner wall of the roadway, wherein the row distance between adjacent rows is 1-10 m; the distance between adjacent weakening drill holes 3 in each row is 0.5 m-5 m;
C. sequentially injecting a softening agent into each weakened borehole 3 by using a retreating type grouting method and under the hydrostatic pressure of more than 2.5, sealing the holes for 1 hour to ensure that the softening agent fully reacts with the hard rock stratum 4, and then repeatedly injecting the softening agent and sealing the holes until the common hardness coefficient of the hard rock stratum 4 is reduced to 3;
D. performing hardness detection on surrounding rocks 6 around the roadway 2, if the Pythiis hardness coefficient of the surrounding rocks 6 is less than 1, entering the step E, and otherwise, completing the control process of the surrounding rocks of the coal mine;
E. constructing a plurality of rows of reinforcing drill holes 5 in surrounding rocks 6 on two sides of the inner wall of the roadway, wherein the row distance between adjacent rows is 1-10 m; the distance between adjacent reinforced drill holes 5 in each row is 0.5-5 m;
F. sequentially injecting hydrochloric acid into each reinforced drill hole 5 by using a retreating type grouting method and sealing holes by using more than 2.5 hydrostatic pressures so as to enable the hydrochloric acid to fully react with the broken cementing substances (carbonate and sulfate) in the surrounding rock 6 to generate corresponding chlorides, injecting sodium carbonate into each reinforced drill hole 5 again after 1 hour of sealing holes, and enabling the sodium carbonate to neutralize the unreacted hydrochloric acid which is added for the first time and then react with various chlorides to generate corresponding carbonate precipitation cements so as to enable the micro precipitation cements in the broken rock to be converted into strong cementing substances; repeating the steps until the Pythiier hardness coefficient of the surrounding rock reaches 5; and finishing the control process of the coal mine surrounding rock.
Further, the diameter of the weakening bore 3 and the diameter of the reinforcement bore 5 are both within the range of 50mm to 100 mm. A bore diameter in this range is most suitable, which would result in construction inconvenience and waste of softener or hardener (hydrochloric acid combined with sodium carbonate) if the bore diameter is too large; if the bore hole diameter is too small this may result in a reduced contact surface for the softening or hardening agent to react with the rock components in the hard rock formation or surrounding rock, thereby increasing the time of the process.
Further, the end of the weakened borehole 4 is at 1/2 thickness of the hard rock formation 4; the end of the reinforcement borehole 5 is at the 1/2 thickness of the surrounding rock 6. The arrangement of the position can increase the contact surface of the injected softening agent or hardening agent and rock components in the hard rock layer 4 or the surrounding rock 6, thereby fully ensuring the chemical reaction of the injected softening agent or hardening agent, and finally realizing the weakening of the hard rock layer 4 and the reinforcement of the surrounding rock 6.
Furthermore, the softening agent is concentrated phosphoric acid with the concentration of 80%, and the softening agent can react with silicon dioxide and calcium carbonate in the rock to generate corresponding salt and water after being injected into the hard rock stratum, so that the ordinary hardness coefficient of the hard rock is reduced, and the purpose of softening the hard rock stratum is achieved.
Claims (4)
1. A coal mine surrounding rock control method based on chemical modification is characterized by comprising the following specific steps:
A. after the tunnel is tunneled, carrying out hardness detection on a hard rock layer above the tunnel, if the coefficient of the Pouler hardness of the hard rock layer exceeds 8, entering the step B, and if not, entering the step D;
B. constructing multiple rows of weakened drill holes in the inner wall of the roadway towards a hard rock stratum, wherein the row spacing between adjacent rows is 1-10 m; the distance between adjacent weakening drill holes in each row is 0.5-5 m;
C. sequentially injecting a softening agent into each weakened borehole by using a retreating type grouting method and under the hydrostatic pressure of more than 2.5, sealing the holes for 1 hour, fully reacting the softening agent with the hard rock stratum, and then repeatedly injecting the softening agent and sealing the holes until the common hardness coefficient of the hard rock stratum is reduced to 3;
D. c, performing hardness detection on surrounding rocks around the roadway, entering the step E if the Pythiis hardness coefficient of the surrounding rocks is smaller than 1, and otherwise, completing the control process of the surrounding rocks of the coal mine;
E. constructing multiple rows of reinforcing drill holes in surrounding rocks on two sides of the inner wall of the roadway, wherein the row spacing between adjacent rows is 1-10 m; the distance between adjacent reinforced drill holes in each row is 0.5-5 m;
F. sequentially injecting hydrochloric acid into each reinforced drill hole by using a retreating type grouting method and sealing the holes by using more than 2.5 hydrostatic pressures so as to enable the hydrochloric acid to fully react with broken cementing substances in the surrounding rocks to generate corresponding chlorides, injecting sodium carbonate into each reinforced drill hole again and sealing the holes after 1 hour of sealing the holes, wherein the sodium carbonate can neutralize the unreacted hydrochloric acid which is added for the first time and then react with various chlorides to generate corresponding carbonate precipitation cements so as to enable the micro precipitation cements in the broken rocks to be converted into strong cementing substances; repeating the steps until the Pythiier hardness coefficient of the surrounding rock reaches 5; and finishing the control process of the coal mine surrounding rock.
2. The coal mine surrounding rock control method based on chemical modification is characterized in that the diameters of the weakening drill holes and the reinforcing drill holes are both in the range of 50-100 mm.
3. The method for coal mine wall rock control based on chemical modification of claim 1, wherein the end of the weakened borehole is at 1/2 thickness of the hard rock stratum; the ends of the reinforcement boreholes are at the 1/2 thickness of the surrounding rock.
4. The method for controlling the surrounding rock of the coal mine based on chemical modification as claimed in claim 1, wherein the softening agent is concentrated phosphoric acid with a concentration of 80%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910922990.7A CN110685688B (en) | 2019-09-27 | 2019-09-27 | Coal mine surrounding rock control method based on chemical modification |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910922990.7A CN110685688B (en) | 2019-09-27 | 2019-09-27 | Coal mine surrounding rock control method based on chemical modification |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110685688A CN110685688A (en) | 2020-01-14 |
| CN110685688B true CN110685688B (en) | 2021-01-01 |
Family
ID=69110656
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910922990.7A Active CN110685688B (en) | 2019-09-27 | 2019-09-27 | Coal mine surrounding rock control method based on chemical modification |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110685688B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111636869A (en) * | 2020-04-26 | 2020-09-08 | 华北科技学院 | Roadway protection structure and method for gob-side roadway |
| CN111946343A (en) * | 2020-07-29 | 2020-11-17 | 山西晋城无烟煤矿业集团有限责任公司 | Method for solving hard top plate collapse problem through ground vertical hole composite jet fracturing |
| CN113738378B (en) * | 2021-09-07 | 2022-10-21 | 西南交通大学 | Chemical rock breaking medium and chemical auxiliary rock breaking method |
| CN114320161B (en) * | 2022-01-20 | 2023-11-03 | 河南理工大学 | Chemical reaming method for coal bed vertical roof cutting and drilling |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3918761A (en) * | 1974-02-14 | 1975-11-11 | Univ Syracuse Res Corp | Chemical comminution of coal and removal of ash including sulfur in inorganic form therefrom |
| SU1384754A1 (en) * | 1986-09-16 | 1988-03-30 | Институт Горного Дела Ан Казсср | Method of mining gently-sloping and sloping ore bodies of low thickness |
| CN101781553A (en) * | 2010-02-05 | 2010-07-21 | 西安科技大学 | Active fracturing reagent for softening coal rock |
| CN102807388A (en) * | 2012-08-24 | 2012-12-05 | 贵州绿水青山环保科技有限公司 | Safe and green mining method for simultaneously reinforcing and mining mineral resource |
| CN103233738A (en) * | 2013-04-27 | 2013-08-07 | 西安科技大学 | Comprehensive weakening method of top coal of heavy-pitch super high seam |
| CN104005766A (en) * | 2014-05-12 | 2014-08-27 | 山西蓝焰煤层气集团有限责任公司 | Chemical method for weakening of top coal |
| CN105909246A (en) * | 2016-06-30 | 2016-08-31 | 太原理工大学 | Horizontal segment blast cracking and chemical weakening method for igneous rock in thick coal seam |
| CN106837353A (en) * | 2017-01-22 | 2017-06-13 | 中南大学 | Filling karst constructing tunnel processing method |
| CN107476807A (en) * | 2017-10-10 | 2017-12-15 | 中国平煤神马能源化工集团有限责任公司 | A kind of coal seam tight roof fracturing method for weakening |
| CN109025999A (en) * | 2018-09-12 | 2018-12-18 | 中国矿业大学 | A kind of one three top coal method for weakening |
| CN109098754A (en) * | 2018-10-22 | 2018-12-28 | 天地科技股份有限公司 | A kind of underground coal mine power top plate impulsion pressure prevention method |
| CN109403978A (en) * | 2019-01-04 | 2019-03-01 | 天地科技股份有限公司上海分公司 | Hard mineral aggregate down-hole mechanical continuous exploitation method |
| CN109538209A (en) * | 2018-09-11 | 2019-03-29 | 中国矿业大学 | A kind of reduction coal seam tight roof method based on electroporation |
| CN110130897A (en) * | 2019-06-13 | 2019-08-16 | 中国神华能源股份有限公司 | Roof weakening solution danger method |
-
2019
- 2019-09-27 CN CN201910922990.7A patent/CN110685688B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3918761A (en) * | 1974-02-14 | 1975-11-11 | Univ Syracuse Res Corp | Chemical comminution of coal and removal of ash including sulfur in inorganic form therefrom |
| SU1384754A1 (en) * | 1986-09-16 | 1988-03-30 | Институт Горного Дела Ан Казсср | Method of mining gently-sloping and sloping ore bodies of low thickness |
| CN101781553A (en) * | 2010-02-05 | 2010-07-21 | 西安科技大学 | Active fracturing reagent for softening coal rock |
| CN102807388A (en) * | 2012-08-24 | 2012-12-05 | 贵州绿水青山环保科技有限公司 | Safe and green mining method for simultaneously reinforcing and mining mineral resource |
| CN103233738A (en) * | 2013-04-27 | 2013-08-07 | 西安科技大学 | Comprehensive weakening method of top coal of heavy-pitch super high seam |
| CN104005766A (en) * | 2014-05-12 | 2014-08-27 | 山西蓝焰煤层气集团有限责任公司 | Chemical method for weakening of top coal |
| CN105909246A (en) * | 2016-06-30 | 2016-08-31 | 太原理工大学 | Horizontal segment blast cracking and chemical weakening method for igneous rock in thick coal seam |
| CN106837353A (en) * | 2017-01-22 | 2017-06-13 | 中南大学 | Filling karst constructing tunnel processing method |
| CN107476807A (en) * | 2017-10-10 | 2017-12-15 | 中国平煤神马能源化工集团有限责任公司 | A kind of coal seam tight roof fracturing method for weakening |
| CN109538209A (en) * | 2018-09-11 | 2019-03-29 | 中国矿业大学 | A kind of reduction coal seam tight roof method based on electroporation |
| CN109025999A (en) * | 2018-09-12 | 2018-12-18 | 中国矿业大学 | A kind of one three top coal method for weakening |
| CN109098754A (en) * | 2018-10-22 | 2018-12-28 | 天地科技股份有限公司 | A kind of underground coal mine power top plate impulsion pressure prevention method |
| CN109403978A (en) * | 2019-01-04 | 2019-03-01 | 天地科技股份有限公司上海分公司 | Hard mineral aggregate down-hole mechanical continuous exploitation method |
| CN110130897A (en) * | 2019-06-13 | 2019-08-16 | 中国神华能源股份有限公司 | Roof weakening solution danger method |
Non-Patent Citations (1)
| Title |
|---|
| 《泥质软岩巷道断层破碎带化学浆液加固技术研究》;马家平等;《能源技术与管理》;20081021(第4期);第40-42页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110685688A (en) | 2020-01-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110685688B (en) | Coal mine surrounding rock control method based on chemical modification | |
| WO2019227852A1 (en) | Fracture relieving method for stress concentration of pillar left in overlying goaf | |
| CN102937030B (en) | Bolting-grouting integrated support method for zonal disintegration of deep roadway surrounding rock | |
| CN109339786B (en) | Directional hydraulic fracturing and cracking method for prefabricated cracks | |
| WO2017096674A1 (en) | An above ground and underground cooperative control method of far and near field roofs of extra-large stoping space | |
| CN103821558B (en) | Coal mine gob filling mining and gob side entry retaining filling process | |
| CN110939442A (en) | Method for treating rock burst by pressure relief source in ground fracturing area | |
| CN111305876A (en) | Deep roadway anchoring-splitting grouting-hydraulic fracturing pressure relief cooperative control method | |
| CN101603431B (en) | Method for reinforcing outburst-prone coal seam cross-cut coal uncovering | |
| CN107060760A (en) | A kind of method that colliery withdraws tunnel presplit blasting caving release | |
| CN107701188A (en) | One kind cuts top destressing method for the mined out side static state spalling of gob side entry driving thin coal pillar | |
| CN1664310A (en) | Control method for coal mine detached island coal pillar rock burst | |
| WO2023273091A1 (en) | Method for preventing and controlling rock bursts in development roadway group | |
| CN103557000B (en) | Method for preventing gob-side entry rock burst through side-drawing filling | |
| CN107387082A (en) | A kind of method for weakening coal seam tight roof | |
| CN111502662B (en) | Prevention and control method for deep pressure relief shallow part reinforcement of rock burst mine advanced coal body | |
| CN111520184A (en) | Comprehensive control system and method for coal mine rock burst and harmful gas | |
| CN113404535A (en) | Method for preventing rock burst by hydraulic fracturing of coal mine underground | |
| CN110344831A (en) | Top release is cut without coal column along the sky lane self-contained Xiang Liu method | |
| WO2016150188A1 (en) | Method for fracturing filler wall left behind in adjacent coal-mining face | |
| CN110656936A (en) | Mine roof directional roof cutting pressure relief method based on static expanding agent | |
| CN111535817A (en) | Working face double-lane tunneling small coal pillar reinforcement construction method | |
| CN107152279A (en) | Wangeviry stope top plate hydraulic fracturing method for weakening and device | |
| CN112160792A (en) | Staged hydraulic fracturing working method for underground hard top plate | |
| US20230160305A1 (en) | Coal bump control method for sectional hydraulic fracturing regions of near vertical ultra thick coal seam |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |