Stability mechanism and control of the pumpable supports in longwall recovery room

作者

Dong Zhang Jianbiao Bai Zhijun Tian Zizheng Zhang
单位

State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology Key Laboratory of Xinjiang Coal Resources Green Mining,Xinjiang Key Laboratory of Coal-bearing Resources Exploration and Exploitation,Xinjiang Engineering Research Center of Green Intelligent Coal Mining,Xinjiang Institute of Engineering Work Safety Key Laboratory on Prevention and Control of Gas and Roof Disasters for Southern Goal Mines,Hunan Provincial Key Laboratory of Safe Mining Techniques of Coal Mines,Hunan University of Science and Technology School of Mines,China University of Mining and Technology
摘要

The load-bearing performance （LBP） of pumpable supports （PPS） is crucial for the stability of longwall pre-driven recovery room （PRR） surrounding rock.However,the unbalanced bearing coefficient （UBC）of the PPS （undertaking unequal load along the mining direction） has not been investigated.A mechanical model of the PRR was established,considering the main roof cantilever beam structure,to derive an assessment formula for the load,the failure criteria,and the UBC of the PPS.Subsequently,the generation mechanisms,and influencing factors of the UBC were revealed.Global sensitivity analysis shows that the main roof hanging length （l2） and the spacing between the PPS （r） significantly impact the UBC.A novel design of the PPS and the coupling control technology were proposed and applied to reduce the UBC of the PPS in the adjacent longwall PRR.Monitor results showed no failure of the PPS at the test site,with the UBC （ζ） reduced to 1.1 consistent with the design value （1.15） basically,fully utilizing the collaborative LBP of the PPS.Finally,the maximum roof-to-floor convergence of the PRR was 234 mm,effectively controlling the stability of the surrounding rock of the PRR and ensuring the mining equipment recovery.
基金项目(Foundation)

thefinancialsupportprovidedbytheXinjiangUygurAutonomousRegionKeyR&DProjectTaskSpecial-DepartmentandDepartmentLinkageProject(No.2022B01051)；MajorProjectofRegionalJointFoundationofChina(No.U21A20107)；HunanProvincialNaturalScienceFoundationofChina(No.2024JJ4021)；theXinjiangUygurAutonomousRegionTianchiIntroductionPlan(No.2024XGYTCYC03)；
文章目录

1.Introduction
2.Analysis of the stability of the main roof structure of the PRR
2.1.Establishment of mechanical model
2.1.1.Mechanical model of the roof structure
2.1.2.Basic assumptions of the mechanical model
2.2.Stability determination of the hanging main roof structure
2.3.Engineering case
2.3.1.Mining geological conditions
2.3.2.Results of field survey
2.4.Stability analysis of the main roof
3.Analysis of the mechanism of PPS in the PRR
3.1.Mechanical model of the load-bearing of PPS
3.2.Analysis of the load-bearing of PPS
3.3.Characteristics of unbalanced bearing on PPS
3.3.1.Unbalanced bearing coefficient of PPS
3.3.2.Interfering factor of unbalanced bearing coefficient
3.3.3.Sobol sensitivity analysis of influencing factors
3.4.Critical stability assessment of PPS
4.Support design and applications for a PRR
4.1.Support scheme design
4.2.Engineering application
5.Discussion
5.1.Fracture structure of the main roof
5.2.Stiffness of the PPS
5.3.Further research
6.Conclusions
引用格式

[1]Zhang D ,Bai J ,Tian Z , et al.Stability mechanism and control of the pumpable supports in longwall recovery room[J].International Journal of Mining Science and Technology,2024,34(07):957-974.