Abstract

The determination of propulsive abutment pressure and deformation characteristics of roadway surrounding rock mass in top-coal caving mining is of great significance for further research on mining stress, roadway support and equipment selection. This paper adopts the method of combining theoretical analysis and field test, taking Helin coal mine j7401 working face as the research object. The relationship between abutment support pressure and roadway surrounding rock mass deformation is revealed by monitoring the stress of transportation and ventilation roadway and observing the deformation of mining roadway. The main conclusions are as follows: when the distance between top-coal caving mining and borehole is about 65 m, the borehole stress begins to exceed the original rock stress, and the peak of the abutment pressure is 15–22 m in front of the working face, ranging from 33 to 39 MPa, which is 3.2–3.8 times the original rock stress. The intersection of propulsive abutment pressure curve and original rock stress curve is located at 8.1 m in front of the working face, the boundary of roadway rapid deformation stage and deceleration deformation stage is 8.9 m ahead of the working face, the distance between the two stages is 0.8 m, and the peak position of propulsive abutment pressure is 19.8 m. The boundary of roadway decelerative deformation stage and stationary small deformation stage is 20.1 m, and the distance between the two stages is 0.3 m. The boundary between the fracture zone and the limit equilibrium zone is the intersection of the propulsive abutment pressure curve and the original rock stress curve. The plastic zone is constituted by the damage zone and the limit equilibrium zone, and the boundary between the plastic zone and the elastic zone is located at the peak of the propulsive abutment pressure. The above study results provide a basis for roadway support and efficient coal mining.

Highlights

  • In this paper, a theoretical analysis and field measurements are integrated to investigate the connection between the advancing abutment pressure and the deformation of the surrounding rock in the roadway of a fully-mechanized coal mine; the j7401 working face of the Helin coal mine is used as the example. 2 Overview of the study background

  • The daily convergence in the front of the working face beyond 60 m is close to 0. These results indicate that the deformation of the surrounding rock is very large in the range of 0~20 m in the front of the working face, is weak in the range of 20 m~60 m, and the surrounding rock is basically unaffected by mining beyond 60 m. 4.2.3 Relationship between advancing abutment pressure and roadway deformation

  • The results show that the boundary between the failure zone and the limit equilibrium zone is the intersection of the advancing abutment pressure curve and the original rock stress line

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Summary

Research Article

Keywords: Fully-mechanized caving mining, Advancing abutment pressure, Roadway deformation, Relationship between stress and deformation License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License Version of Record: A version of this preprint was published at Environmental Earth Sciences on November 1st, 2021. See the published version at https://doi.org/10.1007/s12665-021-10045-6. Hongyan Qin1,2, Zhiheng Cheng 1,2,3*, Zhenhua Ouyang1,2*, Xidong Zhao1,2, Jicheng Feng1,2

We define
Ventilation roadway
Transportation roadway
Peak of advancing abutment pressure
Conclusions
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