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ORIGINAL RESEARCH article

Front. Built Environ.

Sec. Geotechnical Engineering

Volume 11 - 2025 | doi: 10.3389/fbuil.2025.1671058

This article is part of the Research TopicAdvances in Buried Structure ResearchView all 4 articles

Long distance laying technology of casing for connected roadway directional borehole in underground coal mine and its application

Provisionally accepted
Kuiying  GaoKuiying Gao1Guo  LiGuo Li1Zhibin  LiZhibin Li2*Haitao  MoHaitao Mo2Yijun  HeYijun He1Xiongwei  LiXiongwei Li2
  • 1Shendong Coal Branch, China Shenhua Energy Co., Ltd., Yulin, China
  • 2CCTEG Xi′an Research Institute (Group)Co., Ltd.,, Xian, China

The final, formatted version of the article will be published soon.

Aiming at the problem of long distance laying of casing for connected roadway directional borehole in underground coal mine, the bending capacity and passing capacity of casing were calculated and analyzed with the large diameter casing of Ф219 × 8.94 mm as the research object. The stress situation in the process of casing running was studied, and the supporting pipe jacking machine was developed and the engineering test was carried out. The results show that the limit dog leg of the casing string is 5.512 ° / 30 m. The smaller borehole diameter has high requirements for dogleg control, and the larger borehole diameter increases the drilling difficulty. The preferred borehole diameter is 330 mm. The casing laying scheme of ' drill machine pulling back + pipe jacking machine pushing ' is put forward. The casing pushing and pulling process should be matched with thrust and tension. Focus on the design of horizontal telescopic guide rail propulsion system and mobile centralizer and clamping release system, the supporting pipe jacking machine was developed. The engineering test was carried out in the directional long borehole between Daliuta Mine and Huojitu Mine. The casing running and cementing achieved good results. The research results can provide reference for the implementation of similar projects.

Keywords: underground coalmine, Directional drilling, long-distance casing laying, the limit curvature, pipe jacking machine

Received: 22 Jul 2025; Accepted: 03 Oct 2025.

Copyright: © 2025 Gao, Li, Li, Mo, He and Li. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Zhibin Li, lizhibin0304@163.com

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