Abstract

To study the impact of mining of the lower protective layer on the deformation and failure characteristics of the upper roadway, these characteristics of an 879 gas drainage roadway were studied and analyzed during the mining of the II 1051 working face of the Zhuxianzhuang coal mine using similar simulation experiments and numerical simulation methods. The results indicate that with the continuous excavation of the working face, the range of impact of the mining stress gradually spreads and exceeds the level of the roadway. At the present time, the roadway is in a mining stress-rising area. The two sides of the roadway are sheared, and the roof and floor are under tension–shear composite failure. The floor is the most gravely damaged—the depth of its damage is 2.5 m, and the depths of damage on either side and of the roof are approximately 1–2 m. During the advancing process of the working face, the deformation of the roadway increases slowly at first, then increases sharply, and tends to be stable thereafter. The deformation of the floor is the largest, followed by those of the two sides and the roof; the values are 800, 400, and 300 mm, respectively.

Highlights

  • The depletion of shallow coal resources in China has led to increasing mining depth in various mining areas, and the problems of coal and gas outbursts in coal mines are increasing

  • The continuous excavation of the working face led to increasingly intense movement of the overlying strata, the weak strata collapsed with mining, and the main roof was broken periodically

  • 2.5 cm away from the roof of No 10 coal seam 15.5 cm away from the roof of No 10 coal seam 33 cm away from the roof of No 10 coal seam 41 cm away from the roof of No 10 coal seam 57 cm away from the roof of No 10 coal seam 70 cm away from the roof of No 10 coal seam the II 1051 working face, the 879 gas drainage roadway in the upper part of the No 10 coal seam lays in the stress-rising area of the overlying strata formed by mining

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Summary

Introduction

The depletion of shallow coal resources in China has led to increasing mining depth in various mining areas, and the problems of coal and gas outbursts in coal mines are increasing. Zhang et al [20] studied the characteristics of strata failure fracture, fracture evolution, and subsidence deformation in the process of the upward mining of deep coal seams They further analyzed the relationship between the strata subsidence deformation curve and the strata fracture, fracture development, and stress state. The literature referred to above primarily investigated the deformation and failure characteristics and stress distribution of the overlying strata and coal roadway in the mining process of the lower protective seam. Based on the abovementioned conditions, through similar simulation experiments and numerical simulations and considering the overlying 879 gas drainage roadway of the Zhuxianzhuang coal mine II 1051 working face of the Huaibei Mining Group as the engineering background, in this study, the deformation and failure characteristics of the upper roadway during the mining of the lower protective layer are investigated. The law that governs the impact of the deformation and failure characteristics of the overlying strata on similar characteristics of the upper roadway and the instability mechanism of the roadway is summarized

Project Profile
Analysis of Test Results
Numerical Simulation Study on Stability of Upper Roadway under Upward Mining
Analysis and Discussion of Numerical Simulation Results
Measurement and Analysis of Roadway Deformation
Conclusion
Conflicts of Interest
Full Text
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