Gob-Side Entry Retained with Soft Roof, Floor, and Seam in Thin Coal Seams: A Case Study

Zhijun Tian,Min Deng,Jianbiao Bai,Shuai Yan,Zizheng Zhang

doi:10.3390/su12031197

Zhijun Tian, Min Deng + Show 3 more

Open Access

https://doi.org/10.3390/su12031197

Copy DOI

Abstract

Gob-side entry retained technology is of great significance to develop coal mining industry sustainably, which can improve the coal recovery rate by mining without the coal pillar. However, scholars and researchers pay little attention to the gob-side entry retained with soft roof, floor, and seam in thin coal seams. In this study, the difficulties and key points of surrounding rock control for gob-side entry retained with soft roof, floor, and seam in thin coal seams were firstly proposed. Secondly, the mechanical model of the interaction between the roadside backfill body and the roof for gob-side entry retained with soft roof, floor, and seam in thin coal seams was established, and the relevant parameters were designed. Finally, the above results were verified by the engineering practice of gob-side entry retained technology and the monitoring of mine pressure on the 1103 working face of the Heilong Coal Mine. Moreover, the effect factors of surrounding rock stability for gob-side entry retained with soft roof, floor, and seam in thin coal seams were discussed using the discrete element method. The results could provide guidance for gob-side entry retained with soft roof, floor, and seam in thin coal seams under similar geological conditions.

Highlights

IntroductionFor sustainable utilization of limited coal resources, it is important to increase the coal recovery rate
In order to alleviate the tight situation of mining replacement, it is of great strategic significance to carry out and develop gob-side entry retained (GER)
This paper firstly proposes the structural characteristics of overburden and seam in thin coal seams (TCMs), androof, presents stability control technology

Summary

Introduction

For sustainable utilization of limited coal resources, it is important to increase the coal recovery rate. China has abundant coal resources with large reserves and diversification. The proven recoverable reserves of thin coal seams (TCMs) are about 6 billion tons, accounting for about 20% of the total coal reserves in China. TCM with a thickness of 0.8~1.3 m account for 73.4%, and the layers of TCMs below medium and hard coal account for 64.59% of the total layers, which have great mining value. Since the mining roadway of the TCM working face is a mixed coal-rock roadway, the drifting speed is slow with a lot of gangue, which may lead to a strain between mining and drifting. High-efficiency mining technology for TCMs is an important technical way to improve the recovery rate of coal resources and achieve sustainable development of coordinated mining. In order to alleviate the tight situation of mining replacement, it is of great strategic significance to carry out and develop gob-side entry retained (GER)

Methods

Findings

Discussion

Conclusion