Zhipeng Tong1, Xiangyang Zhang1, Chengfu Gu2
1School of Mining Engineering, Anhui University of Scinece and Technology, Huainan, China
2Selian No.2 Coal Mine, Coal Industry Branch, Huaihe Energy Group Co., Ltd., Ordos, Inner Mongolia Autonomous Region, China
To effectively improve the stability of the surrounding rock in the roadway formed by composite roof cutting of a three-soft (soft roof, coal, and floor) coal seam, the force deformation characteristics of a roadway self-formed by roof cutting were analyzed through similarity simulation, numerical simulation, and field measurement under the engineering background of return air groove on 12406 working face in Selian No.2 Mine. The results showed that a significant pressure relief effect was achieved when the advanced supporting pressure periodicly moved forward to the presplit and cut roof, the stress concentration coefficient on the entity coal side was reduced by about 0.5, and the surrounding rock stress in the roadway was effectively improved. The surrounding rock deformation and the supporting force presented asymmetric distribution characteristics, the deformation rate exhibited a three-section law, and the stress in the gob displayed the recovery characteristic of circular progressive increase from the perimeter to the center. Considering the spatial geological conditions of this mine, a collaborative and integrated surrounding rock supporting countermeasure with “NPR constant-resistance anchor + hollow grouting anchor + retractable U-steel + floor bolting and grouting +door-like scaffold” as the core supporting structure was proposed. The results of the test section manifested that the surrounding rock deformation in the roadway was significantly educed compared with the original supporting scheme.
Three-soft coal seams, Composite roof, Roadway formed by roof cutting, Surrounding rock deformation, Supporting countermeasure
Zhipeng Tong, Xiangyang Zhang, Chengfu Gu. Study on Stress Characteristics and Supporting Countermeasures of Surrounding Rock in Roadway Formed by Composite Roof Cutting in Three-soft Coal Seam. Academic Journal of Architecture and Geotechnical Engineering (2023) Vol. 5, Issue 7: 42-50. https://doi.org/10.25236/AJAGE.2023.050707.
 Zhang C, Zhao YX, Han PH. et al. (2022.) Coal pillar failure analysis and instability evaluation methods: A short review and prospect, Engineering Failure Analysis, Volume 138,106344.
 Ashok Kumar, Petr Waclawik, Rajendra Singh. et al. (2019). Performance of a coal pillar at deeper cover: Field and simulation studies. International Journal of Rock Mechanics and Mining Sciences, Volume 113, Pages 322-332.
 Li XY, Zhang N, Xie ZZ. et al. (2019). Study on Efficient Utilization Technology of Coal Pillar Based on Gob-Side Entry Driving in a Coal Mine with Great Depth and High Production. Sustainability 11, no. 6: 1706.
 Chen, A. (2021). Width Design of Small Coal Pillar of Gob-Side Entry Driving in Soft Rock Working Face and Its Application of Zaoquan Coal Mine. Advances in Civil Engineering, 2021: p. 1-10.
 Li, JZ, Yin ZQ, Li Y. et al. (2019). Waste rock filling in fully mechanized coal mining for goaf-side entry retaining in thin coal seam. Arabian Journal of Geosciences, 12(16): p. 509.
 Zhang Q, He MC, Guo S. et al. (2022). Investigation on the key techniques and application of the new-generation automatically formed roadway without coal pillars by roof cutting. International Journal of Rock Mechanics and Mining Sciences, Volume 152, 105058.
 Xue H, Wang Q, Jiang B. et al. (2023). Study on the method of pressure relief by roof cutting and absorbing energy in deep coal mines. Bulletin of Engineering Geology and the Environment, 82(8): p. 298.
 Ning JG, Wang J, Jiang LS., et al. (2017). Fracture analysis of double-layer hard and thick roof and the controlling effect on strata behavior: A case study. Engineering Failure Analysis, Volume 81, Pages 117-134.
 Hu CW, Wang EY, Li Q. et al. (2022). Research on the Key Technology of Gob-Side Entry Retaining by Roof Cutting for Thick and Hard Sandstone Roofs. Sustainability 14, no. 16: 9941.
 Tan YL, Yu FH, Ning JG. et al. (2016). Adaptability theory of roadside support in gob-side entry retaining and its supporting design. Journal of China Coal Society 41(02):376-382 (in Chinese)
 Kang HP, Wang JH, Lin J. (2010). Case Studies of Rock Bolting In Coal Mine Roadways. Chinese Journal of Rock Mechanics and Engineering. 29(04):649-664. (in Chinese)