Evolution characteristics of overburden structure in inclined fully mechanized caving under residual coal pillars of the upper layer
In the stratified fully mechanized caving of ultra-thick coal seams, the inclined layout of upper and lower caving faces leads to lower fully mechanized caving face intermittently crossing residual coal pillars of the upper layer. This results in complex overburden breakage and mine pressure behavio...
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | zho |
| Published: |
Editorial Department of Industry and Mine Automation
2024-12-01
|
| Series: | Gong-kuang zidonghua |
| Subjects: | |
| Online Access: | http://www.gkzdh.cn/article/doi/10.13272/j.issn.1671-251x.2024110079 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832591125124218880 |
|---|---|
| author | LIU Yong WANG Hongwei WU Xuesong TIAN Chengpeng GUAN Rongfu NIE Yunxiao FAN Zhiwei CAO Peipei |
| author_facet | LIU Yong WANG Hongwei WU Xuesong TIAN Chengpeng GUAN Rongfu NIE Yunxiao FAN Zhiwei CAO Peipei |
| author_sort | LIU Yong |
| collection | DOAJ |
| description | In the stratified fully mechanized caving of ultra-thick coal seams, the inclined layout of upper and lower caving faces leads to lower fully mechanized caving face intermittently crossing residual coal pillars of the upper layer. This results in complex overburden breakage and mine pressure behavior, posing challenges to surrounding rock control and hindering safe coal production. Based on the 250203 lower fully mechanized caving face at Yanbei Coal Mine of Gansu Huating Coal Power Co., Ltd., methods of physical similarity simulation experiments, numerical modeling, and field measurements were applied to study the overburden movement and stress distribution evolution characteristics under residual coal pillars of the upper layer during inclined fully mechanized caving. The instability characteristics of residual coal pillars of the upper layer and the variation patterns of surrounding rock support pressure under the disturbance of lower fully mechanized caving were clarified. The overburden of the inclined working face was categorized into internal and external fields, and the evolution characteristics of the overburden structure when the lower fully mechanized caving face crossed the residual coal pillars were revealed. The results showed that the mining of the lower fully mechanized caving face induced instability in residual coal pillars of the upper layer, resulting in large-scale overburden collapse. The roof structure within the disturbed zone evolved progressively into a composite structure of "low-level inverted step cantilever beams and high-level large masonry beams". When the working face was 15 m from the residual coal pillar, the maximum vertical stress of the pillar reached 46.7 MPa, an increase of 9.9% compared to the pre-mining state, with significant pillar deformation observed. When the working face was directly beneath the residual coal pillar, the stress concentration zones of the pillar displayed an approximately crescent-shaped distribution. As the inclined position of the lower fully mechanized caving face relative to the residual coal pillars changed, the overburden breakage in the external field exhibited an approximately symmetrical trapezoidal shape. The dynamic instability of the structure caused the overburden collapse in the internal field to evolve through stages of "asymmetric double arches", "symmetric double arches", and "single arch". These findings provide significant guidance for the safe mining of stratified fully mechanized caving faces in ultra-thick coal seams. |
| format | Article |
| id | doaj-art-c01e349b8db54af4bbb8539a4a680798 |
| institution | Kabale University |
| issn | 1671-251X |
| language | zho |
| publishDate | 2024-12-01 |
| publisher | Editorial Department of Industry and Mine Automation |
| record_format | Article |
| series | Gong-kuang zidonghua |
| spelling | doaj-art-c01e349b8db54af4bbb8539a4a6807982025-01-23T02:17:44ZzhoEditorial Department of Industry and Mine AutomationGong-kuang zidonghua1671-251X2024-12-015012465810.13272/j.issn.1671-251x.2024110079Evolution characteristics of overburden structure in inclined fully mechanized caving under residual coal pillars of the upper layerLIU Yong0WANG HongweiWU Xuesong1TIAN Chengpeng2GUAN Rongfu3NIE Yunxiao4FAN Zhiwei5CAO Peipei6Yanbei Coal Mine, Gansu Huating Coal Power Co., Ltd., Huating 744100, ChinaYanbei Coal Mine, Gansu Huating Coal Power Co., Ltd., Huating 744100, ChinaCollege of Energy Engineering, Xi'an University of Science and Technology, Xi'an 710054, ChinaYanbei Coal Mine, Gansu Huating Coal Power Co., Ltd., Huating 744100, ChinaTechnical Center, Huating Coal Industry Group Co., Ltd., Huating 744100, ChinaTechnical Center, Huating Coal Industry Group Co., Ltd., Huating 744100, ChinaYanbei Coal Mine, Gansu Huating Coal Power Co., Ltd., Huating 744100, ChinaIn the stratified fully mechanized caving of ultra-thick coal seams, the inclined layout of upper and lower caving faces leads to lower fully mechanized caving face intermittently crossing residual coal pillars of the upper layer. This results in complex overburden breakage and mine pressure behavior, posing challenges to surrounding rock control and hindering safe coal production. Based on the 250203 lower fully mechanized caving face at Yanbei Coal Mine of Gansu Huating Coal Power Co., Ltd., methods of physical similarity simulation experiments, numerical modeling, and field measurements were applied to study the overburden movement and stress distribution evolution characteristics under residual coal pillars of the upper layer during inclined fully mechanized caving. The instability characteristics of residual coal pillars of the upper layer and the variation patterns of surrounding rock support pressure under the disturbance of lower fully mechanized caving were clarified. The overburden of the inclined working face was categorized into internal and external fields, and the evolution characteristics of the overburden structure when the lower fully mechanized caving face crossed the residual coal pillars were revealed. The results showed that the mining of the lower fully mechanized caving face induced instability in residual coal pillars of the upper layer, resulting in large-scale overburden collapse. The roof structure within the disturbed zone evolved progressively into a composite structure of "low-level inverted step cantilever beams and high-level large masonry beams". When the working face was 15 m from the residual coal pillar, the maximum vertical stress of the pillar reached 46.7 MPa, an increase of 9.9% compared to the pre-mining state, with significant pillar deformation observed. When the working face was directly beneath the residual coal pillar, the stress concentration zones of the pillar displayed an approximately crescent-shaped distribution. As the inclined position of the lower fully mechanized caving face relative to the residual coal pillars changed, the overburden breakage in the external field exhibited an approximately symmetrical trapezoidal shape. The dynamic instability of the structure caused the overburden collapse in the internal field to evolve through stages of "asymmetric double arches", "symmetric double arches", and "single arch". These findings provide significant guidance for the safe mining of stratified fully mechanized caving faces in ultra-thick coal seams.http://www.gkzdh.cn/article/doi/10.13272/j.issn.1671-251x.2024110079ultra-thick coal seamsstratified fully mechanized cavingresidual coal pillarsinclined working faceoverburden structure |
| spellingShingle | LIU Yong WANG Hongwei WU Xuesong TIAN Chengpeng GUAN Rongfu NIE Yunxiao FAN Zhiwei CAO Peipei Evolution characteristics of overburden structure in inclined fully mechanized caving under residual coal pillars of the upper layer Gong-kuang zidonghua ultra-thick coal seams stratified fully mechanized caving residual coal pillars inclined working face overburden structure |
| title | Evolution characteristics of overburden structure in inclined fully mechanized caving under residual coal pillars of the upper layer |
| title_full | Evolution characteristics of overburden structure in inclined fully mechanized caving under residual coal pillars of the upper layer |
| title_fullStr | Evolution characteristics of overburden structure in inclined fully mechanized caving under residual coal pillars of the upper layer |
| title_full_unstemmed | Evolution characteristics of overburden structure in inclined fully mechanized caving under residual coal pillars of the upper layer |
| title_short | Evolution characteristics of overburden structure in inclined fully mechanized caving under residual coal pillars of the upper layer |
| title_sort | evolution characteristics of overburden structure in inclined fully mechanized caving under residual coal pillars of the upper layer |
| topic | ultra-thick coal seams stratified fully mechanized caving residual coal pillars inclined working face overburden structure |
| url | http://www.gkzdh.cn/article/doi/10.13272/j.issn.1671-251x.2024110079 |
| work_keys_str_mv | AT liuyong evolutioncharacteristicsofoverburdenstructureininclinedfullymechanizedcavingunderresidualcoalpillarsoftheupperlayer AT wanghongwei evolutioncharacteristicsofoverburdenstructureininclinedfullymechanizedcavingunderresidualcoalpillarsoftheupperlayer AT wuxuesong evolutioncharacteristicsofoverburdenstructureininclinedfullymechanizedcavingunderresidualcoalpillarsoftheupperlayer AT tianchengpeng evolutioncharacteristicsofoverburdenstructureininclinedfullymechanizedcavingunderresidualcoalpillarsoftheupperlayer AT guanrongfu evolutioncharacteristicsofoverburdenstructureininclinedfullymechanizedcavingunderresidualcoalpillarsoftheupperlayer AT nieyunxiao evolutioncharacteristicsofoverburdenstructureininclinedfullymechanizedcavingunderresidualcoalpillarsoftheupperlayer AT fanzhiwei evolutioncharacteristicsofoverburdenstructureininclinedfullymechanizedcavingunderresidualcoalpillarsoftheupperlayer AT caopeipei evolutioncharacteristicsofoverburdenstructureininclinedfullymechanizedcavingunderresidualcoalpillarsoftheupperlayer |