Conditions of dry-placed filling in footwall

Aiming to reduce overburden haulage distance and cost in mining on one side of an open pit mine, it is expedient to place overburden fill on spoil banks for process road construction. At the same time, the combination of adverse factors, typical of footwall rocks, promotes initiation of deep-level earth slides in stratified deposits, which affect stability of the fill and parameters of the haulage berms. It is proposed to carry out a stable fill design using the data on a true-life earth slide. The coefficients of contact friction are found from the system of equations on equilibrium in the fill before and after earth slide. Using the characteristics of slip resistance and the stability criterion, the permissible fill height is calculated with regard to additional weight from a loaded dump truck. Given the permissible road width by the stability criterion disagrees with the standards of Construction Code SP 37.13330.2012 for a dump truck of given size, the road is constructed by means of partial undercutting of underlying rocks in the seam floor. It is found that at an angle of the fill base less than 14°, the fill body of roads is usually stable. At steeper angles, the fill body undergoes various-size deformations. The mining and geometrical model in the form of contour lines of topographic functions of seam floor dip angles is used for real-time routing of process road axis in the zones of minimum inclinations of the fill base. Then, with the calculated parameters, roads are constructed for actual geotechnical conditions. The earth slide risk reduction procedures for haulage berms in footwall rocks are discussed.

Bakhaeva S. P., Ananenko E. V. Conditions of dry-placed filling in footwall. MIAB. Mining Inf. Anal. Bull. 2020;(9):55-64. [In Russ]. DOI: 10.25018/0236-1493-2020-9-0-55-64.

S.P. Bakhaeva, Dr. Sci. (Eng.), Professor, T.F. Gorbachev Kuzbass State Technical University, Mining Institute, 650000 Kemerovo, Russia, e-mail: bsp.mdg@kuzstu.ru,
E.V. Ananenko, Head of Geo-Mechanics Sector, Siberian branch of VNIMI JSC (Research Institute of Mining Geo-mechanics and Mine Surveying), 653004, Prokopyevsk, Russia, e-mail: chernykhev@kuzstu.ru.

S.P. Bakhaeva, e-mail: bsp.mdg@kuzstu.ru.

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