Abstract
In order to solve the problem that the surrounding rock control of the pre-excavation double-retracement channel is difficult and a large number of coal pillars cannot be recovered. Taking chuancaogeban coal mine as the engineering background, the mechanical model in the process of gradual connection between coal mining face and main withdrawal channel is constructed, and the response characteristics of surrounding rock in withdrawal channel are simulated and verified by FLAC3D numerical calculation model. The instability mechanism of this kind of roadway is revealed, and a comprehensive stability control technology of surrounding rock and the technology of recovering all coal pillars are proposed, and the field engineering verification is carried out. The results show that when the coal mining face is close to the main retracement channel, when the distance between the coal mining face and the main retracement channel is 4 m, the coal body between the coal mining face and the main retracement channel enters an unstable state. Using 8 m wide filling wall to replace the coal pillar between the main retracement channel and the auxiliary retracement channel can ensure the stability of the surrounding rock of the two retracement channels after the coal mining face passes through the main retracement channel. In addition, the retained auxiliary withdrawal channel also has the functions of auxiliary production and coal pillar recovery, and finally realizes the technology of pre-excavation double withdrawal channel without coal pillar abandonment. As the coal mining face gradually approaches the main retracement channel, the surrounding rock stress of the main retracement channel and the auxiliary retracement channel has significant dynamic development. Based on the development law of the deviatoric stress of the surrounding rock, the combined control technology of ‘ pre-cutting roof + high water material pillar + grouting reinforcement + single pillar + metal mesh + steel ladder belt + bolt + anchor cable ‘ in different regions is proposed. The field monitoring results show that during the removal of coal mining equipment, the surrounding rock deformation of the withdrawal channel is small, the surrounding rock control effect is good, and the equipment is safely and efficiently removed; during the recovery of coal pillars, the surrounding rock deformation of the retained auxiliary withdrawal channel meets the needs of production. The recoverable resources of coal seams will increase by 747,000t, and the economic benefits will increase by 117 million yuan.
Similar content being viewed by others
Data availability
All data generated or analysed during this study are included in this published article.
References
Wang, Z., Wang, S. & Su, Z. New technology of collaborative work between face mining andbracket withdrawal. Coal Sci. Technol. 49(02), 21–29. https://doi.org/10.13199/j.cnki.cst.2021.02.003 (2021).
Hao, Y. Research on application of equipment pullback technology in 8.8m super-high fully mechanized mining face. Coal Sci. Technol. 50(S2), 50–60. https://doi.org/10.13199/j.cnki.cst.2022-2113 (2022).
Xiaolin, W. A. N. G. et al. Influence of high mining velocity on periodic weighting during fullymechanized mining in a shallow seam. J. China Univ. Min. Technol. 41(03), 349–354 (2012).
Fulian, H. et al. Rotation mechanism of key blocks during end-mining period of fullymechanized caving in close distance coal seams and its application. Chin. J. Rock Mech. Eng. 42(08), 1832–1846. https://doi.org/10.13722/j.cnki.jrme.2022.0851 (2023).
Yang, J., Zhang, R. & Lu, S. Insight into the mechanism of roadway protection against highadvance stress by roof pre-splitting. J. China Univ. Min. Technol. 53(02), 264–276. https://doi.org/10.13247/j.cnki.jcumt.20230304 (2024).
Lv, Y. & Xin, T. Rapid equipment withdrawing from heavy fully mechanized top coalcaving mining face and roof control technology during mining terminal period. Nei Menggu Mei Tan Jing Ji 23, 34–35. https://doi.org/10.13487/j.cnki.imce.015559 (2019).
Li Yang, Wang Nan, Liu Lingshen, et al. Research on surrounding rock stability and dynamic joint supporttechnology for longwall panel through complex structural zones. Coal Science and Technology. 2025, 1–14[2026–03–25]. https://link.cnki.net/urlid/11.2402. TD.20250821.1801.002.
Hongtao, L. et al. Multi-step support technology for support remove gateway in thickcoal seam with high in-situ stress. J. China Coal Soc. 50(07), 3388–3399. https://doi.org/10.13225/j.cnki.jccs.2024.0900 (2025).
Zhang, X. & He, W. The roadway arrangement technology of effectively shortening theback channel and the pillar between the main roadway in the fullymechanized coal face. Coal Sci. Technol. 50(S2), 83–87. https://doi.org/10.13199/j.cnki.cst.2022-1987 (2022).
Yanbo, Y. A. N. G. et al. Reasonable position of equipment withdrawal roadway in shallowburied full height mining working face. Coal Technol. 44(02), 1–5. https://doi.org/10.13301/j.cnki.ct.2025.02.001 (2025).
Gao, L. Working face in Daliuta Coal Mine width of coal pillars in double removing gateway interval of 52508. Energy Energy Conserv. 11, 274–277. https://doi.org/10.16643/j.cnki.14-1360/td.2024.11.100 (2024).
Liu, X., Ren, Q. & Zhou, H. Reasonable width of protective coal pillars for double withdrawachannels in shallow buried coal seam. Shaanxi Mei Tan 43(08), 8–13. https://doi.org/10.20120/j.cnki.issn.1671-749x.2024.0802 (2024).
Dang, Y. Surrounding rock reinforcement technology of pre-excavated withdrawal channel in fully mechanized top-coal caving face. Energy Energy Conserv. 02, 173–175+201. https://doi.org/10.16643/j.cnki.14-1360/td.2026.02.021 (2026).
Zhang, J. et al. Research and application of prefilled concrete wall to reduce the size of stopping mining coal pillar. Geofluids https://doi.org/10.1155/2022/8526755 (2022).
Zizhao, F. U. et al. Stress superposition characteristics and roof structure control ofrecovery room in close distance coal seam. Coal Sci. Technol. 53(06), 383–395 (2025).
Shuai, Y. et al. Stability mechanism and active-passive joint control of surrounding rock in longwall recovery room. J. Min. Saf. Eng. 40(04), 774–785. https://doi.org/10.13545/j.cnki.jmse.2023.0077 (2023).
Weihua, S. O. N. G. et al. tudy on the characteristic of overburden rock structure and support system of the retraction channel in layered fully mechanized caving face. Sci. Rep. 14, 1360–1360. https://doi.org/10.1038/S41598-024-52015-5 (2024).
Huang, K. Surrounding rock control of the retreat roadway during the finalmining stage in an ultra-thick coal seam with fully mechanized top coalcaving. Coal Eng. 58(01), 76–84 (2026).
Zhao, W. Multi-step support technology for support remove gateway in thick coal seam with high in-situ stress. Miner. Eng. Res. 34(04), 29–34. https://doi.org/10.13582/j.cnki.1674-5876.2019.04.005 (2019).
Li, Y., Almalki, M. A. & Li, C. Support design of main retracement passage in fully mechanised coal mining face based on numerical simulation. Appl. Math. Nonlinear Sci. 7, 553–560. https://doi.org/10.2478/AMNS.2021.1.00059 (2021).
Wang, C. et al. Dynamic structural evolution of overlying strata during shallow coal seam longwall mining. Int. J. Rock Mech. Min. Sci. 103, 20–32 (2018).
Lei, S. et al. Study on roadway layout and surrounding rock control of isolated island panel. Sci. Rep. 13, 22021. https://doi.org/10.1038/s41598-023-49385-7 (2023).
Shui, Z. et al. Numerical study of stability of mining roadways with 6.0-m section coal pillars under influence of repeated mining. Int. J. Min. Sci. Technol. 27, 141–147. https://doi.org/10.1016/j.ijmst.2016.11.003 (2017).
Shuli, W. A. N. G. et al. Numerical investigation of coal pillar failure under simultaneous static and dynamic loading. Int. J. Rock Mech. Min. Sci. 138, 104645. https://doi.org/10.1016/j.ijrmms.2021.104645 (2021).
Truster, T. J., Moslehy, A. & Alshibli, K. A. Effects of crystal orientation, temperature, deviatoric stress, and confining stress on creep of rock salt. Int. J. Rock Mech. Min. Sci. 183, 105747. https://doi.org/10.1016/j.ijrmms.2024.105747 (2024).
Wang, Z. et al. Research of surrounding rock control of gob-side entry retaining based on deviatoric stress distribution characteristics. Sustainability 14(9), 5660. https://doi.org/10.3390/su14095660 (2022).
Acknowledgements
The authors are unable or have chosen not to specify which data has been used.
Funding
This research is supported by high-level talent scientific research start-up fund project of the Heilongjiang University of Science and Technology. (Encore number: HKDQDJ202402), Lvliang Special Program for the Introduction of High-Level Scientific and Technological Talents (Encore number:2024RC26) and Scientific and Technological Innovation Project of Higher Education Institutions in Shanxi Province (Encore number: 2024L377).
Author information
Authors and Affiliations
Contributions
Jiao Zhang: The establishment of the theory, simulation research and the preparation of the full text. Zhan Shi: On-site monitoring. Chao Wu: Auxiliary simulation research. FuKun Xiao: Research on auxiliary theory. Lei Shi: Assist in writing articles.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
About this article
Cite this article
Zhang, J., Shi, Z., Wu, C. et al. Research and application of pre-excavated double withdrawal channel technology without coal pillar abandonment. Sci Rep (2026). https://doi.org/10.1038/s41598-026-47412-x
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41598-026-47412-x
