Experimental Studies of the Stability of Haulage Drifts on Pitching Seams With Different Methods of Protection

Abstract

Purpose: Study of the stability of haulage drifts on pitching seams with different protection methods in order to assess their operational condition and create safe working conditions at excavation sites in deep coal mines. Methodology: The research used a comprehensive approach, including research analysis of the problem under study, field experiment and data processing. Conclusions: As a result of the conducted research, it was established that when protecting the haulage drifts on pitching seams of solids of coal, in the area of influence of cleaning works, the cross-sectional area of the preparatory work decreases by 50 % or more, and the deformation of protective structures after losing their stability reaches the maximum value λ = 0.8. At the same time, the fastening in the product is deformed, and the side rocks collapse. The industrial situation provokes injuries from collapses. When protecting the roll-back stretch with wooden piles, after their compression (when the relative deformation reaches the maximum values of λ = 0.6), the loss of the cross-sectional area is about 30 %, and the bearing capacity of the protective structures allows you to limit the movement of side rocks and prevent their collapse. Implications of research: In order to create safe working conditions for miners in preparatory workings in mines with steep coal beds, it is recommended to use flexible protective structures that limit the movement of side rocks in the mined space. Originality: A functional dependence in the form of a time series was established, which takes into account the change in the relative deformation of protective structures during the operation of the production at the excavation site.

Assessment of the state of the rock mass around the crosscuts under additional deformation disturbances

“…Within the mine field, layers of mark Zh coal with a thick ness of 1.2-3.0 meters are subject to development. The mine is one of the most mechanized and automated enterprises in the industry; it is dangerous due to the gas factor and the possibil ity of gasdynamic manifestations of rock pressure, in particu lar sudden emissions of gas and coal [16,17]. The analysis of data on coal reserves shows that in order to maintain sustain able production at the achieved level (2,500 thousand tons per year), timely reproduction of the working face line in promis ing layers m 4 2 , l 3 , k 5 is not enough.…”