Research on Physical Similarity Simulation of Mining Uphill and Downhill at the Large-Angle Working Face

Meng Zhang,Yidong Zhang,Haizhu Li,Hongjun Guo,Ming Ji

doi:10.1155/2019/7696752

Meng Zhang, Yidong Zhang + Show 3 more

Open Access

https://doi.org/10.1155/2019/7696752

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Abstract

With the development of coal mining and the continuous expansion of mining intensity, large dip angle comprehensive mechanized coal mining as an important development direction and goal has become a worldwide research topic in the coal industry. The working face faces many production problems that need to be solved, such as the large-angle downhill mining, the large-angle uphill mining, and other complicated geological conditions (such as skew, anticline, and fault). In view of the above problems, with the specific conditions of Xinji No. 2 Mine, through the physical similarity simulation, the research on the roof movement law of the fully mechanized mining face under the mining conditions of large dip angle (depression angle and elevation angle are more than 40° and 20°, respectively) is studied. The distribution law of abutment pressure, movement law, and distribution range of water-conducting fracture zone after mining are emphasized. Meanwhile, the paper analyzes and compares the related mining pressure law of inclined longwall fully mechanized mining face under general conditions, forming a systematic, comprehensive, and scientific understanding of the law of mining pressure under such conditions. This achievement is of great significance to the prevention and control of water, support design, safety production, environmental improvement, improvement of enterprise efficiency, and advancement of coal science and technology.

Highlights

It can be said that the comprehensive safety support technology of mining uphill and downhill at the large-angle working face has not yet achieved real success in China, and the main reason is that the basic problems of fully mechanized mining technology in the large dip angle coal seam have not been completely solved
(4) When the working face has not been advanced to the observation line, the influence of the preabutment pressure on the activity of the overlying strata is different in each section. e analysis of this phenomenon is of great significance to the advance support of the roadway. e influence of the advancing support pressure on the rock strata activity in the latter part of the downhill mining section is obvious. e rock layer has a displacement of about 60 mm; the influence of the other measuring lines on the preabutment pressure is not obvious
According to the geological conditions and lithologic parameters of the E1108 working face, a physical similarity model was established. e distribution law of abutment pressure, movement law, and distribution range of waterconducting fracture zone after mining are analyzed emphatically. e analysis results show the following: (1) e immediate roof of the downhill mining section is not easy to cave under the influence of the pressure along the layer, and the collapse drawing pace is longer; the uphill mining section is affected by the tensile force along the layer, and the collapse drawing pace is shorter, basically falls with the mining. e old roof presents different collapsing characteristics in the downhill mining section, the syncline axis, and the uphill mining section

Summary

Introduction

According to the published literature and achievements, the occurrence conditions of coal seam in countries outside China are relatively simple, and the research on large-angle fully mechanized mining technology is mainly focused on mining equipment [20,21,22]. It can be said that the comprehensive safety support technology of mining uphill and downhill at the large-angle working face has not yet achieved real success in China, and the main reason is that the basic problems of fully mechanized mining technology in the large dip angle coal seam have not been completely solved. E successful research of this subject can effectively utilize the core technology of fully mechanized coal mining to achieve high productivity and high efficiency in coal mine enterprises under complex geological conditions of large dip angle coal seams (including large-angle uphill and downhill mining) and has a good prospect of popularization and application

Physical Simulation Experimental Program

Experimental Principles

Seventh ird measuring line irteenth Seventeenth Twenty-third Seventh

Activity Lows of Rock Strata during Mining

Conclusion