Stability analysis of rock fracture and support performance in steeply dipping ore deposits with massive mining stopes

Abstract

In this paper, taking a mine in Xinjiang as the engineering background, through the combination of physical simulation experiment, 3DEC numerical calculation, theoretical analysis and field monitoring, the fracture evolution characteristics of overlying strata and its influence on the stability of support under unbalanced loading conditions are systematically studied. The results show that under the action of gravity-dip effect, the non-uniform filling of gangue leads to the typical cross-layer migration characteristics of overburden caving shape and roof bearing arch. The unstable inclined masonry structure is formed in the middle and upper areas, which is prone to rotation and sliding instability, forming impact pressure. The mining stress of the overlying strata changes significantly due to the mining of the coal seam. The lower the overlying strata, the greater the peak stress, the smaller the stress value in the goaf, and the greater the stress change. The amplitude and instability probability of the support migration increase with the decrease of the working resistance of the support, the increase of the friction between the roof and the support, and the increase of the partial load of the support. Finally, the prevention and control measures of roof caving crushing support in steeply dipping and large mining height working face are put forward.

Keywords:

• Steeply dipping coal seam
• large mining height
• overlying strata deformation-failure
• support-surrounding rock
• stability control

Acknowledgments

The author thanks the editors and the staff for their efforts. The authors thank the anonymous reviewers for their comments and suggestions to improve the manuscript. The authors acknowledge and appreciate the technical support provided by Coal Mine No. 2130 of Xinjiang Coking Coal (Group) Co., Ltd.

Data availability

Our data are collated from field studies. The numerical parameters are based on the geological data of a coal reservoir in Xinjiang Province, China, which are listed in Table 1.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of the PRC (52174126, 51974227), Major Scientific and Technological Innovation Projects in Shandong Province (2019JZZY020326), Shaanxi Outstanding Youth Science Fund Project (2023-JC-JQ-42) and Shaanxi University Youth Innovation Team Project.