Geodynamic risks of mining in highly stressed rock mass

Abstract

The paper discloses that geological faults and phenomena associated therewith are the main risks of mining. The phenomena of fault activity and specific features of near-fault zones, determining their impact on the stability of mine workings and other man-made objects are discussed in detail. Different sections of faults are classified according to the degree and types of risk. The main attention is paid to the most stressed zones, where the fault is a closely spaced crack in the rock, characterized by specific strength and rock-bump hazard effect. The paper discloses that although mining operations change the stress-strain state of the massif, nonetheless, most of hazardous situations and geodynamic phenomena during excavation occur in tectonically stressed zones that already existed in the massif. In these areas, man-made overload during mining results to the formation of extremely stressed geodynamically hazardous zones. Thus, geodynamic zoning, which includes the identification of faults and block structure, assessment of their activity, as well as reconstruction of the stress-strain state of both the blocks and the near-fault zones, is the key method for assessing risks of geodynamic phenomena.

Integrated stress–strain analysis of pillars in apatite–nepheline ore mining by sublevel caving

“…Геомеханические процессы в основном проявляются в виде хрупкого разрушения пород в боках выработок. Наличие зон хрупкого разрушения породных целиков по высоте на их контуре оказывает значительное влияние на устойчивость горных выработок [9][10][11], так как происходит изменение размеров породного обнажения и их формы, что приводит к интенсификации геомеханических процессов, в частности в кровле горных выработок, где породы и так чаще всего находятся в перенапряженном состоянии [12][13][14].…”

Assessment of excavation intersections’ stability in jointed rock masses using the discontinuum approach

“…Within the mines of the Khibiny Massif, the tectonic distribution of stresses is observed at deep levels: horizontal stresses exceed vertical components (Shabarov et al, 2019;Mazurov et al, 2019;Petrov, 2007). Depending on the depth, the values of horizontal stresses change according to nonlinear laws.…”

Assessing the zones of tectonic fault influence on dynamic rock pressure manifestation at Khibiny deposits of apatite-nepheline ores

“…A. D. GVISHIANI 1,2 , Chief Scientist of Geophysical Center RAS, Head of the Department, Academician of RAS, Doctor of Physical and Mathematical Sciences V. N. TATARINOV 1,2 V , Chief Researcher, Head of Laboratory, Chief Researcher, Doctor of Engineering Sciences A. I. MANEVICH 1,3…”

“…The mentioned dynamic rock pressure manifestations (DRPM) result in flow process disruption or more serious consequences and require preventive actions based on effective prediction techniques. However, despite research done in this area, the problem of such phenomena prediction and prevention remains unresolved [1][2][3][4] since, among other things, it requires simultaneous account of a lot of factors [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. One of these factors is the influence of tectonic faults, the size of these zones of influence cannot be directly measured and requires advanced study.…”

“…In 2019, at the Yenisei site (Nizhne-Kansk massif, southern part of the Yenisei Ridge), the construction of an underground research laboratory (URL) began to substantiate the final decision on its geological suitability for the disposal of high-level radioactive waste (HLRW) [1,2]. The international and Russian documents regulating the safety of handling HLRW state that the main barrier guaranteeing the safety of HLRW isolation for their entire period of radiobiological hazard (up to 100 thousand years) is the geological environment [3][4][5].…”