Mechanism of Dynamic Failure in Roadways with Thick and Competent Roof Strata: A Case Study
Rock and coal dynamic failures have a higher chance to occur when thick and competent roof strata are presented, which can build up a high level of energy. This paper studied the fracturing characteristics of the competent roof strata during longwall face retreat and their effects on roadways’ stabi...
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| Format: | Article |
| Language: | English |
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Wiley
2019-01-01
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| Series: | Advances in Civil Engineering |
| Online Access: | http://dx.doi.org/10.1155/2019/2618543 |
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| author | Jinshuai Guo Liqiang Ma Feng Ju Chengguo Zhang Fangtian Wang Shuai Guo |
| author_facet | Jinshuai Guo Liqiang Ma Feng Ju Chengguo Zhang Fangtian Wang Shuai Guo |
| author_sort | Jinshuai Guo |
| collection | DOAJ |
| description | Rock and coal dynamic failures have a higher chance to occur when thick and competent roof strata are presented, which can build up a high level of energy. This paper studied the fracturing characteristics of the competent roof strata during longwall face retreat and their effects on roadways’ stability to gain an improved understanding of the rock dynamic failure occurred in roadways as well as the associated ground controls. The results indicated that the main reason of dynamic failure in roadways was the structural change of lateral main roof over a chain pillar, which transformed from the cantilever beam in the period of primary mining impact (PMI) to the triangular arch in the period of secondary mining impact (SMI). Based on corresponding mechanical models developed for the lateral main roof over the chain pillar, it was calculated that the force on roadways’ roof in the period of SMI was 3.7 times larger than that in the period of PMI. Then, the dynamic failure control method of increasing the chain pillar width was proposed. The stress distribution and deformation of roadways with different chain pillar widths were simulated using FLAC3D. The results indicate that as the pillar width increases, the influence of secondary mining on roadways’ stability decreases, and a threshold of not less than 30 m pillar width was suggested. The outcomes of this study would provide guidance for the design of chain pillars where thick and competent roof strata are presented. |
| format | Article |
| id | doaj-art-7cabbf8a2bee4c169f7b8c17253f6606 |
| institution | OA Journals |
| issn | 1687-8086 1687-8094 |
| language | English |
| publishDate | 2019-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in Civil Engineering |
| spelling | doaj-art-7cabbf8a2bee4c169f7b8c17253f66062025-08-20T02:07:26ZengWileyAdvances in Civil Engineering1687-80861687-80942019-01-01201910.1155/2019/26185432618543Mechanism of Dynamic Failure in Roadways with Thick and Competent Roof Strata: A Case StudyJinshuai Guo0Liqiang Ma1Feng Ju2Chengguo Zhang3Fangtian Wang4Shuai Guo5State Key Laboratory for Geomechanics & Deep Underground Engineering, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, ChinaCollege of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, ChinaState Key Laboratory for Geomechanics & Deep Underground Engineering, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, ChinaSchool of Minerals and Energy Resources Engineering, The University of New South Wales, Sydney 2052, AustraliaState Key Laboratory of Coal Resources and Safe Mining, School of Mines, China University of Mining and Technology, Xuzhou 221116, ChinaState Key Laboratory for Geomechanics & Deep Underground Engineering, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, ChinaRock and coal dynamic failures have a higher chance to occur when thick and competent roof strata are presented, which can build up a high level of energy. This paper studied the fracturing characteristics of the competent roof strata during longwall face retreat and their effects on roadways’ stability to gain an improved understanding of the rock dynamic failure occurred in roadways as well as the associated ground controls. The results indicated that the main reason of dynamic failure in roadways was the structural change of lateral main roof over a chain pillar, which transformed from the cantilever beam in the period of primary mining impact (PMI) to the triangular arch in the period of secondary mining impact (SMI). Based on corresponding mechanical models developed for the lateral main roof over the chain pillar, it was calculated that the force on roadways’ roof in the period of SMI was 3.7 times larger than that in the period of PMI. Then, the dynamic failure control method of increasing the chain pillar width was proposed. The stress distribution and deformation of roadways with different chain pillar widths were simulated using FLAC3D. The results indicate that as the pillar width increases, the influence of secondary mining on roadways’ stability decreases, and a threshold of not less than 30 m pillar width was suggested. The outcomes of this study would provide guidance for the design of chain pillars where thick and competent roof strata are presented.http://dx.doi.org/10.1155/2019/2618543 |
| spellingShingle | Jinshuai Guo Liqiang Ma Feng Ju Chengguo Zhang Fangtian Wang Shuai Guo Mechanism of Dynamic Failure in Roadways with Thick and Competent Roof Strata: A Case Study Advances in Civil Engineering |
| title | Mechanism of Dynamic Failure in Roadways with Thick and Competent Roof Strata: A Case Study |
| title_full | Mechanism of Dynamic Failure in Roadways with Thick and Competent Roof Strata: A Case Study |
| title_fullStr | Mechanism of Dynamic Failure in Roadways with Thick and Competent Roof Strata: A Case Study |
| title_full_unstemmed | Mechanism of Dynamic Failure in Roadways with Thick and Competent Roof Strata: A Case Study |
| title_short | Mechanism of Dynamic Failure in Roadways with Thick and Competent Roof Strata: A Case Study |
| title_sort | mechanism of dynamic failure in roadways with thick and competent roof strata a case study |
| url | http://dx.doi.org/10.1155/2019/2618543 |
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