Deformation and failure characteristics of gas drainage drilling-reaming coal mass in non-uniform stress field
The deformation and failure characteristics of coal around gas drainage boreholes in deep soft and low permeability coal seams affect coal seam gas pre-drainage. Based on the condition of non-uniform stress field, the mechanical model of borehole disturbed coal mass was developed, the analytical sol...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | zho |
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Editorial Office of Journal of China Coal Society
2023-04-01
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| Series: | Meitan xuebao |
| Subjects: | |
| Online Access: | http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.WS22.0655 |
| _version_ | 1797793840946479104 |
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| author | Chao XU Liangliang QIN Kai WANG Shimin WU Rong ZHANG Haijun GUO Longyong SHU |
| author_facet | Chao XU Liangliang QIN Kai WANG Shimin WU Rong ZHANG Haijun GUO Longyong SHU |
| author_sort | Chao XU |
| collection | DOAJ |
| description | The deformation and failure characteristics of coal around gas drainage boreholes in deep soft and low permeability coal seams affect coal seam gas pre-drainage. Based on the condition of non-uniform stress field, the mechanical model of borehole disturbed coal mass was developed, the analytical solutions of stress, strain and displacement in the damaged zone, plastic zone and elastic zone of borehole disturbed coal mass were deduced, the influence law of factors such as lateral pressure coefficient, load condition, cohesion and hole expanding behavior on the “three zone” distribution of disturbed coal mass were analyzed, and the reliability of the theoretical model was verified through engineering examples. The results show that under the condition of non-uniform stress field, the plastic zone and damaged zone of disturbed coal mass are elliptical distribution. With the increase of lateral pressure coefficient, the length of the upper and lower wings of the plastic zone and damaged zone of disturbed coal mass becomes larger and larger, and the radius of the plastic zone and damaged zone in the direction of smaller stress is greater than the radius of the two zones in the direction of large stress. The radius of plastic zone and damaged zone of coal mass increases with the increase of vertical load, and decreases with the increase of initial cohesion and residual cohesion. The influence of vertical load on its shape can be ignored. When the borehole diameter is expanded from 0.1 m to 0.5 m, the coal mass 0−1.0 m away from the borehole center produces a strong disturbance, the coal mass 1.0−4.6 m produces a weak disturbance, and the coal mass after 4.6 m has almost no influence. Through the field example of No.16032 bottom pumping roadway hydraulic reaming in the Guhanshan coal mine, it is observed that the disturbed coal mass in the reaming section has a high degree of damage. Based on the coal output, the reaming diameter is deduced to be 1.5 m, and then the deformation and damage characteristics of drilling reaming coal mass are obtained through theoretical calculation and numerical simulation respectively. The two are in good agreement, so as to verify the reliability of the theoretical model. |
| first_indexed | 2024-03-13T02:54:06Z |
| format | Article |
| id | doaj.art-fcf4e2de33cf47018bb1240b9b382294 |
| institution | Directory Open Access Journal |
| issn | 0253-9993 |
| language | zho |
| last_indexed | 2024-03-13T02:54:06Z |
| publishDate | 2023-04-01 |
| publisher | Editorial Office of Journal of China Coal Society |
| record_format | Article |
| series | Meitan xuebao |
| spelling | doaj.art-fcf4e2de33cf47018bb1240b9b3822942023-06-28T08:10:19ZzhoEditorial Office of Journal of China Coal SocietyMeitan xuebao0253-99932023-04-014841538155010.13225/j.cnki.jccs.WS22.0655WS22-0655Deformation and failure characteristics of gas drainage drilling-reaming coal mass in non-uniform stress fieldChao XU0Liangliang QIN1Kai WANG2Shimin WU3Rong ZHANG4Haijun GUO5Longyong SHU6Beijing Key Laboratory of Accurate Mining of Co-associated Energy, China University of Mining and Technology-Beijing, Beijing 100083, ChinaSchool of Emergency Management and Safety Engineering, China University of Mining and Technology-Beijing, Beijing 100083, ChinaBeijing Key Laboratory of Accurate Mining of Co-associated Energy, China University of Mining and Technology-Beijing, Beijing 100083, ChinaSchool of Emergency Management and Safety Engineering, China University of Mining and Technology-Beijing, Beijing 100083, ChinaFaculty of Safety Science and Engineering, Civil Aviation University of China, Tianjin 300300, ChinaBeijing Key Laboratory of Accurate Mining of Co-associated Energy, China University of Mining and Technology-Beijing, Beijing 100083, ChinaMine Safety Technology Branch, China Coal Research Institute, Beijing 100013, ChinaThe deformation and failure characteristics of coal around gas drainage boreholes in deep soft and low permeability coal seams affect coal seam gas pre-drainage. Based on the condition of non-uniform stress field, the mechanical model of borehole disturbed coal mass was developed, the analytical solutions of stress, strain and displacement in the damaged zone, plastic zone and elastic zone of borehole disturbed coal mass were deduced, the influence law of factors such as lateral pressure coefficient, load condition, cohesion and hole expanding behavior on the “three zone” distribution of disturbed coal mass were analyzed, and the reliability of the theoretical model was verified through engineering examples. The results show that under the condition of non-uniform stress field, the plastic zone and damaged zone of disturbed coal mass are elliptical distribution. With the increase of lateral pressure coefficient, the length of the upper and lower wings of the plastic zone and damaged zone of disturbed coal mass becomes larger and larger, and the radius of the plastic zone and damaged zone in the direction of smaller stress is greater than the radius of the two zones in the direction of large stress. The radius of plastic zone and damaged zone of coal mass increases with the increase of vertical load, and decreases with the increase of initial cohesion and residual cohesion. The influence of vertical load on its shape can be ignored. When the borehole diameter is expanded from 0.1 m to 0.5 m, the coal mass 0−1.0 m away from the borehole center produces a strong disturbance, the coal mass 1.0−4.6 m produces a weak disturbance, and the coal mass after 4.6 m has almost no influence. Through the field example of No.16032 bottom pumping roadway hydraulic reaming in the Guhanshan coal mine, it is observed that the disturbed coal mass in the reaming section has a high degree of damage. Based on the coal output, the reaming diameter is deduced to be 1.5 m, and then the deformation and damage characteristics of drilling reaming coal mass are obtained through theoretical calculation and numerical simulation respectively. The two are in good agreement, so as to verify the reliability of the theoretical model.http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.WS22.0655non-uniform stresselastoplastic analysisreamingdisturbed coal massside pressure coefficient |
| spellingShingle | Chao XU Liangliang QIN Kai WANG Shimin WU Rong ZHANG Haijun GUO Longyong SHU Deformation and failure characteristics of gas drainage drilling-reaming coal mass in non-uniform stress field Meitan xuebao non-uniform stress elastoplastic analysis reaming disturbed coal mass side pressure coefficient |
| title | Deformation and failure characteristics of gas drainage drilling-reaming coal mass in non-uniform stress field |
| title_full | Deformation and failure characteristics of gas drainage drilling-reaming coal mass in non-uniform stress field |
| title_fullStr | Deformation and failure characteristics of gas drainage drilling-reaming coal mass in non-uniform stress field |
| title_full_unstemmed | Deformation and failure characteristics of gas drainage drilling-reaming coal mass in non-uniform stress field |
| title_short | Deformation and failure characteristics of gas drainage drilling-reaming coal mass in non-uniform stress field |
| title_sort | deformation and failure characteristics of gas drainage drilling reaming coal mass in non uniform stress field |
| topic | non-uniform stress elastoplastic analysis reaming disturbed coal mass side pressure coefficient |
| url | http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.WS22.0655 |
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