scholarly journals GEOMECHANICAL MONITORING OF OPEN-PIT WALL HARD ROCK MASS WITH GEOPHYSICAL RESEARCH METHODS

2016 ◽  
Author(s):  
Konstantin Konstantinov
Keyword(s):  
Rock Mass ◽  
Research Methods ◽  
Hard Rock ◽  
Open Pit ◽  
Geophysical Research ◽  
Geomechanical Monitoring

scholarly journals Planetary fracturing and lineaments revealed in the Kovdor magnetite–apatite ore deposit by open pit mining

2020 ◽  
pp. 30-34
Author(s):  
I. B. Agarkov ◽  
◽  
I. M. Ignatenko ◽  
V. A. Dunaev ◽  
I. S. Kryuchkov ◽  
...  
Keyword(s):  
Rock Mass ◽  
Hard Rock ◽  
Laser Scanner ◽  
Open Pit ◽  
Open Pit Mining ◽  
Mining Operations ◽  
Structural Mapping ◽  
Remote Assessment ◽  
Tectonic Origin

The analysis of the studies into fracturing of Zhelezny pitwall rock mass over the period from 1989 to 2019 proves that planetary fracturing is represented by faults, carbonatite dykes and single fractures oriented in the same direction as the prevailing regional lineaments on the Kola Peninsula. Planetary fracturing is assumed as a system of regular-oriented fractures. The planetary fracturing also includes lineaments of tectonic origin. The scientists think the faults registered in the pitwall rock mass and codirectional with the lineaments will accompany mining operations down to the full depth of the pit, up to the full extraction of magnetite–apatite ore reserves. While preparing this article, the authors have collected, generalized and analyzed the data of geological and structural mapping implemented by VIOGEM’s experts over the period from 1989 to 2019. VIOGEM’s procedure of geological and structural mapping ensures continuous documentation of extensional tectonics at high referencing accuracy (to 50 cm), as well as determination of inaccessible azimuths and angles of fractures by remote assessment of their orientations in pit walls using a laser scanner and photographic techniques to study the structure of hard rock mass and the behavior of permanent benches.

scholarly journals Geophysical signs of hard rock disturbance

2020 ◽  
pp. 58-65
Author(s):  
Diakov A. Iu ◽  
Keyword(s):  
Rock Mass ◽  
Wave Field ◽  
Hard Rock ◽  
Quantitative Estimation ◽  
Geological Structure ◽  
Study Data ◽  
Open Pit ◽  
Electromagnetic Signal ◽  
Mining Operations ◽  
Stability Parameters

Introduction. Development of deep open pits requires reliable knowledge on conditions of rocks at the hard rock mass to locate potentially hazardous sectors which have considerable impact on efficiency and rationality of a deposit’s development. Definition of disturbed zones at the open pit benches is an actual scientific and practical task in terms of supporting stability and functionality of such facilities. Research aim is to study geophysical signs of disturbance of hard rocks by data of nondestructive ground-penetrating radar (GPR) observation of the surrounding rock mass at the working open pit benches in order to estimate their geological structure and differentiate by disturbance degree. Methodology. Nowadays, GPR data is overwhelmingly interpreted based on comprehensive analysis of amplitude, frequency and phase characteristics of an electromagnetic signal and without an attribute analysis of the wave field. When using the structural approach, based on the analysis of the dynamic and kinematic characteristics of the wave field, to identify hard rock disturbance areas, it becomes possible to significantly increase the accuracy of their determination and localization according to the nondestructive subsurface GPR research. Results. Based on GPR measurements, the author has studied geophysical signs of disturbed rock zones identification at the open pit benches which consist in a quantitative estimation of change in reflection response amplitude characteristic, permittivity of a section and Q factor attribute. Conclusion. Using the established relationships with the proposed analysis of geophysical signs, the GPR study data can contribute to the adoption of differentiated and providing greater stability parameters of benches and mining operations.

scholarly journals Rockslides on limestone cliffs with subhorizontal bedding in the southwestern calcareous area of China

2014 ◽  
Vol 14 (9) ◽  
pp. 2627-2635 ◽  
Author(s):  
Z. Feng ◽  
B. Li ◽  
Y. P. Yin ◽  
K. He
Keyword(s):  
Numerical Modeling ◽  
Rock Mass ◽  
Hard Rock ◽  
Compression Fracture ◽  
Field Observations ◽  
Mountainous Areas ◽  
Hard Rocks ◽  
Rupture Plane ◽  
Rock Collapse ◽  
Cliff Retreat

Abstract. Calcareous mountainous areas are highly prone to geohazards, and rockslides play an important role in cliff retreat. This study presents three examples of failures of limestone cliffs with subhorizontal bedding in the southwestern calcareous area of China. Field observations and numerical modeling of Yudong Escarpment, Zengzi Cliff, and Wangxia Cliff showed that pre-existing vertical joints passing through thick limestone and the alternation of competent and incompetent layers are the most significant features for rockslides. A "hard-on-soft" cliff made of hard rocks superimposed on soft rocks is prone to rock slump, characterized by shearing through the underlying weak strata along a curved surface and backward tilting. When a slope contains weak interlayers rather than a soft basal, a rock collapse could occur from the compression fracture and tensile split of the rock mass near the interfaces. A rockslide might shear through a hard rock mass if no discontinuities are exposed in the cliff slope, and sliding may occur along a moderately inclined rupture plane. The "toe breakout" mechanism mainly depends on the strength characteristics of the rock mass.

General concept of determining the parameters of non-mining walls of ultra-deep diamond deposits development open pits

2021 ◽  
pp. 48-53
Author(s):  
I. V. Zyryanov ◽  
A. N. Akishev ◽  
I. B. Bokiy ◽  
N. M. Sherstyuk
Keyword(s):  
Rock Mass ◽  
Structural Relaxation ◽  
Slope Angle ◽  
Field Tests ◽  
Friction Angle ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Open Pit ◽  
Open Pit Mining ◽  
Relaxation Coefficient

A specific feature of open pit mining of diamond deposits in Western Yakutia is the construction of the open pits in the zone of negative ambient temperatures, which includes thick permafrost rock mass, and which is at the same time complicated by the influence of cryogenic processes on deformation of pit wall benches. The paper presents the comparative analysis of strength characteristics in frozen and thawed rocks, stability of benches during mining, the general geomechanical approach to the determination of parameters of non-mining walls of the ultra-deep open pit diamond mines, and the parameters of nonmining walls and benches. Optimization of open pit wall configuration should primarily be based on the maximum utilization of the strength properties of frozen rocks in combination with the development of new approaches, calculation schemes and methods for assessing stability of open pit walls and benches of unconventional design, including the non-mining vertical benches. The main design characteristic that determines the parameters of open pit walls is the structural tectonic relaxation coefficient, which specifies the calculated value of cohesion in rock mass. For the diamond deposits, the values of the structural relaxation coefficient were obtained in a series of field tests and back calculations. Full-scale tests were carried out both during exploration operations in underground mines and in open pits. The accuracy of determining the values of the structural relaxation coefficient in the range of 0.085–0.11 is confirmed by the parameters of non-mining walls in an open pit mine 385–640 m deep, with overall slope angles of 38–55° and a steeper H 0.35–0.5 lower part having the slope angle of up to 70° with average strength characteristics of 7.85–11.84 MPa and the internal friction angle of 28.1–37.4°. Using the natural load-bearing capacity of rock mass to the full advantage, which the values of the structural relaxation coefficient of deposits show, allows optimization of open pit wall slope design and minimization of stripping operations.

Sign in / Sign up

Export Citation Format

Share Document