Justification of rational caving shield angles and canopy paths of displacement in powered roof supports

The criteria of effective operation of powered roof supports (shields) are the angle of the caving shield inclination relative to the canopy and the trajectory of the canopy displacement in the plane perpendicular to the longwall face. The values of the inclination angle of the caving shield relative to the canopy are substantiated for the minimum mineable thickness of coal seams and for the minimum height of the powered support unit. For the maximum rock— steel friction coefficient f = 0.4, the angle of the caving shield inclination relative to the canopy should be at least 22° for the minimum mineable thickness of seams and at least 14–15° for the minimum height of shields, which corresponds to the friction coefficient f = 0.25–0.26. It is found that the main cause of the unsatisfactory operation of powered roof supports in coal mining under unstable or fractured immediate roof is the displacement of the canopy towards the goaf during powered support setting. Ideally, there should be no canopy displacements along the roof, but this is unachievable within the whole range of the shield support expandability due to the structural concept. However, it is allowable that the canopy displaces towards the face during the shield support setting over the whole range of its expandability since this has no adverse effect on the load applied to the support unit. The perfect trajectory of the canopy displacement is presented. The trajectory eliminates the canopy displacement towards the goaf during the shield support setting, and is achieved via the reasonable selection of the structural and kinematic parameters of the caving shield and other elements influencing formation of this trajectory.

Yu.V. Turuk, Sysoev N. I., Lugantsev B. B., Streltsov S. V., Bogomazov A. A. Justification of rational caving shield angles and canopy paths of displacement in powered roof supports. MIAB. Mining Inf. Anal. Bull. 2024;(4):134-144. DOI: 10.25018/0236_1493_2024_ 4_0_134.

Yu.V. Turuk¹, Dr. Sci. (Eng.), Assistant Professor, Professor, e-mail: uraturuk@mail.ru, ORCID ID: 0000-0002-4257-0744,
N.I. Sysoev², Dr. Sci. (Eng.), Professor, Professor, e-mail: sysoevngmo@gmail.com, ORCID ID: 0000-0002-0372-427Х,
B.B. Lugantsev², Dr. Sci. (Eng.), Assistant Professor, Professor, e-mail: boris4721@mail.ru, ORCID ID: 0000-0002-8296-7922,
S.V. Streltsov¹, Cand. Sci. (Eng.), Assistant Professor, e-mail: streltcov_s@rambler.ru, ORCID ID: 0000-0003-4989-4327,
A.A. Bogomazov¹, Cand. Sci. (Eng.), Assistant Professor, e-mail: sbog@rambler.ru, ORCID ID: 0000-0002-7176-3393,
¹ Shakhty Automobile Road Institute, Branch of the Platov South-Russian State Polytechnic University (NPI), 346500, Shakhty, Russia,
² M.I. Platov South-Russian State Polytechnic University (NPI), 346428, Novocherkassk, Russia.

Yu.V. Turuk, e-mail: uraturuk@mail.ru.

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