FACTORS OF DEFORMATION MECHANISMS IN PITWALL ROCK MASS WITH IN-DEPTH STEEPLY DIPPING BEDDING

In-depth steeply dipping bedding in pitwall rock mass largely affects slope stability. Deformation of such slopes can occur by different mechanisms. The Russian practice of stability estimation of such slopes consists in applying correction to the results obtained for an isotropic slope. However, this approach neglects cohesion, which results in underestimation of ultimate angles of pitwalls. In this respect, it is very important to reveal features of deformation of pitwall rock mass during mining based on in-situ observations. The problem was solved by physical modeling with equivalent materials. The modeling helped finding pitwall deformation features as functions of structure and strength of the pitwall rock mass. It is revealed that in rock mass with steep reversal dip of bedding and varied strength characteristics, the deformation mechanisms can be bending and shear of layer, or inclination with turnover. The main result is in-situ determination of factors of the slope deformation mechanism. Such factor is the ratio of horizontal and vertical displacements with shrill prevalence of the horizontal displacements (to 90% of the total displacement). The reduction in this ratio points at the approaching transition from the incline of layers to their shear and, thus, to the slope failure.


Acknowledgements: The study was supported by the Russian Science Foundation, Project No. 1777-10101.


For citation: Tsirel S. V., Pavlovich A. A., Melnikov N.Ya. Factors of deformation mechanisms in pitwall rock mass with in-depth steeply dipping bedding. MIAB. Mining Inf. Anal. Bull. 2019;(9):52-61. [In Russ]. DOI: 10.25018/0236-1493-2019-09-0-52-61.

Keywords

Physical modeling, method of equivalent materials, pitwall stability, slope deformation, displacement observations, displacement vector, bedded slopes, reversal dip of layers, turnover of layers.

Issue number: 9
Year: 2019
ISBN: 0236-1493
UDK: 622.83, 622.271.33
DOI: 10.25018/0236-1493-2019-09-0-52-61
Authors: Tsirel S. V., Pavlovich A. A., Melnikov N. Ya.

About authors: S.V. Tsirel, Dr. Sci. (Eng.), Chief Researcher, e-mail: tsirel58@mail.ru, A.A. Pavlovich, Cand. Sci. (Eng.), Assistant, e-mail: pavlovich_aa@pers.spmi.ru, N.Ya. Melnikov, Graduate Student, Engineer, e-mail: melnikyar@yandex.ru, Saint Petersburg Mining University, 199106, Saint-Petersburg, Russia. Corresponding author: N.Ya. Melnikov, e-mail: melnikyar@yandex.ru.

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