Instability Model of a Coal Wall with Large Mining Height under Excavation Unloading Conditions
On the basis of the stress field characteristics of surrounding rocks at a coal wall on a working face with a large mining height, the theories of unloading rock mass mechanics and fracture mechanics were used to establish a model of the excavation unloading field effect of the coal wall, and its in...
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| Format: | Article |
| Language: | English |
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Wiley
2020-01-01
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| Series: | Advances in Civil Engineering |
| Online Access: | http://dx.doi.org/10.1155/2020/8863602 |
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| author | Lei Li Feng zhang |
| author_facet | Lei Li Feng zhang |
| author_sort | Lei Li |
| collection | DOAJ |
| description | On the basis of the stress field characteristics of surrounding rocks at a coal wall on a working face with a large mining height, the theories of unloading rock mass mechanics and fracture mechanics were used to establish a model of the excavation unloading field effect of the coal wall, and its instability mechanism under the action of unloading stress field was analyzed. Results show that the coal mining process is the unloading process of coal and rock masses, and the stress field of surrounding rocks at the coal wall turns into an unloading stress field that consists of original and unloading stresses. Under the action of unloading stress field, cracks in the coal wall will undergo instability, propagation, and combination in the form of composite-type cracks and will gradually evolve into a wedge structure. The wedge stability is inversely related to roof pressure P0, unloading force T, and intersection angle φ of structural planes. Elevating the wall-supporting force Ph, the initial supporting force of supports on the working face and the cohesion C of coal body can effectively control the occurrence of coal wall caving accidents and contribute to the safe mining of working faces with a large mining height. |
| format | Article |
| id | doaj-art-bc46d7c2fbfa4ee88cc89a8fc3a73606 |
| institution | Kabale University |
| issn | 1687-8086 1687-8094 |
| language | English |
| publishDate | 2020-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in Civil Engineering |
| spelling | doaj-art-bc46d7c2fbfa4ee88cc89a8fc3a736062025-02-03T06:05:46ZengWileyAdvances in Civil Engineering1687-80861687-80942020-01-01202010.1155/2020/88636028863602Instability Model of a Coal Wall with Large Mining Height under Excavation Unloading ConditionsLei Li0Feng zhang1Business Division of Mining Design of Tiandi Technology Co., Ltd., Beijing 100013, ChinaState Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan, Anhui Province 232001, ChinaOn the basis of the stress field characteristics of surrounding rocks at a coal wall on a working face with a large mining height, the theories of unloading rock mass mechanics and fracture mechanics were used to establish a model of the excavation unloading field effect of the coal wall, and its instability mechanism under the action of unloading stress field was analyzed. Results show that the coal mining process is the unloading process of coal and rock masses, and the stress field of surrounding rocks at the coal wall turns into an unloading stress field that consists of original and unloading stresses. Under the action of unloading stress field, cracks in the coal wall will undergo instability, propagation, and combination in the form of composite-type cracks and will gradually evolve into a wedge structure. The wedge stability is inversely related to roof pressure P0, unloading force T, and intersection angle φ of structural planes. Elevating the wall-supporting force Ph, the initial supporting force of supports on the working face and the cohesion C of coal body can effectively control the occurrence of coal wall caving accidents and contribute to the safe mining of working faces with a large mining height.http://dx.doi.org/10.1155/2020/8863602 |
| spellingShingle | Lei Li Feng zhang Instability Model of a Coal Wall with Large Mining Height under Excavation Unloading Conditions Advances in Civil Engineering |
| title | Instability Model of a Coal Wall with Large Mining Height under Excavation Unloading Conditions |
| title_full | Instability Model of a Coal Wall with Large Mining Height under Excavation Unloading Conditions |
| title_fullStr | Instability Model of a Coal Wall with Large Mining Height under Excavation Unloading Conditions |
| title_full_unstemmed | Instability Model of a Coal Wall with Large Mining Height under Excavation Unloading Conditions |
| title_short | Instability Model of a Coal Wall with Large Mining Height under Excavation Unloading Conditions |
| title_sort | instability model of a coal wall with large mining height under excavation unloading conditions |
| url | http://dx.doi.org/10.1155/2020/8863602 |
| work_keys_str_mv | AT leili instabilitymodelofacoalwallwithlargeminingheightunderexcavationunloadingconditions AT fengzhang instabilitymodelofacoalwallwithlargeminingheightunderexcavationunloadingconditions |