Fractal characteristics of seismic process in rock mass surrounding the excavation at mining. Mathematical modelling and analysis

2016 ◽  
Author(s):  
M. O. Eremin ◽  
P. V. Makarov
Keyword(s):  
Rock Mass ◽  
Mathematical Modelling ◽  
Seismic Process ◽  
Fractal Characteristics

scholarly journals A Fractal Model for Characterizing Hydraulic Properties of Fractured Rock Mass under Mining Influence

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Xiaoli Liu ◽  
Tao Liang ◽  
Sijing Wang ◽  
Kumar Nawnit
Keyword(s):  
Fractal Dimension ◽  
Rock Mass ◽  
Permeability Coefficient ◽  
Fractured Rock ◽  
Length Distribution ◽  
Fracture Network ◽  
Fractal Model ◽  
Physical Model Test ◽  
Fractured Rock Mass ◽  
Fractal Characteristics

In this paper, two basic assumptions are introduced: (1) The number and length distribution of fractures in fractured rock mass are in accordance with the fractal law. (2) Fluid seepage in the fractures satisfies the cubic law. Based on these two assumptions, the fractal model of parallel seepage and radial seepage in fractured rock mass is established, and the seepage tensor of fracture network which reflects the geometric characteristics and fractal characteristics of fracture network under two kinds of seepage is derived. The influence of fracture geometry and fractal characteristics on permeability is analyzed, and the validity and accuracy of the model are verified by comparing the calculated results of the theoretical model and physical model test. The results show that the permeability coefficient K of fracture network is a function of the geometric (maximum crack length Lmax, fractured horizontal projection length L0, diameter calculation section porosity Φ, fracture strike α, and fracture angle θ) and fractal characteristics (fracture network fractal dimension Df and seepage flow fractal dimension DT). With the increase of fractal dimension Df, the permeability coefficient increases. With the increase of DT, the permeability coefficient decreases rapidly. And the larger the Df (Df>1.5), the greater the change of permeability coefficient K with DT.

Stability Analysis of Central Haulage in Baluba Copper Mine

2014 ◽  
Vol 638-640 ◽  
pp. 822-828
Author(s):  
Gao Hui Yao ◽  
Yi Ming Wang ◽  
Kai Jian Hu
Keyword(s):  
Rock Mass ◽  
Stability Analysis ◽  
Mathematical Modelling ◽  
Rock Bolts ◽  
The Poor ◽  
Support Measures ◽  
Cable Bolts ◽  
Induced Stresses ◽  
Protection Pillar ◽  
Grouted Rock Bolts

Site observations were conducted to investigate the reasons for the poor current rock-mass conditions being experienced in essential crosscuts, to provide recommendations for remedial support measures. Conceptual analyses of mining induced stresses within abutment pillars were undertaken using elastic analytical and mathematical modelling. The results showed that damage to the crosscuts is due to high mining-induced stresses, with the major stress probably acting vertically, the protection pillar for the 480 Level crosscut should be at least 100 m wide. The research demonstrated that only 2.4 m grouted rock-bolts and timber sets is not enough in these conditions, so the 480 Level and 580 Level central haulage should be re-supported with a combination of 4.0 m pre-tensioned cable-bolts, a 75 mm layer of steel mesh (or fibre) reinforced shotcrete, and even steel arch sets with lots of log.

scholarly journals Rock Burst Mechanics: Insight from Physical and Mathematical Modelling

10.14311/1071 ◽  
2008 ◽  
Vol 48 (6) ◽  
Author(s):  
J. Vacek ◽  
J. Vacek ◽  
J. Chocholoušová
Keyword(s):  
Rock Mass ◽  
Mathematical Modelling ◽  
Mathematical Models ◽  
Rock Burst ◽  
Material Properties ◽  
Open Space ◽  
Time Dependent ◽  
Rock Bursts ◽  
Uranium Mines ◽  
Physical And Mathematical Models

Rock burst processes in mines are studied by many groups active in the field of geomechanics. Physical and mathematical modelling can be used to better understand the phenomena and mechanisms involved in the bursts. In the present paper we describe both physical and mathematical models of a rock burst occurring in a gallery of a coal mine.For rock bursts (also called bumps) to occur, the rock has to possess certain particular rock burst properties leading to accumulation of energy and the potential to release this energy. Such materials may be brittle, or the rock burst may arise at the interfacial zones of two parts of the rock, which have principally different material properties (e.g. in the Poíbram uranium mines).The solution is based on experimental and mathematical modelling. These two methods have to allow the problem to be studied on the basis of three presumptions:· the solution must be time dependent,· the solution must allow the creation of cracks in the rock mass,· the solution must allow an extrusion of rock into an open space (bump effect). 

scholarly journals Stress Distribution in a Coal Seam before and after Bump Initiation

10.14311/260 ◽  
2001 ◽  
Vol 41 (4-5) ◽  
Author(s):  
J. Vacek
Keyword(s):  
Rock Mass ◽  
Stress Distribution ◽  
Coal Seam ◽  
Mathematical Modelling ◽  
Rock Burst ◽  
Open Space ◽  
Longwall Mining ◽  
Time Dependent ◽  
Deep Tunnel ◽  
Before And After

This paper deals with to the behaviour of open rock that occurs, for example, during longwall mining in coal mines, in deep tunnel, or shaft excavation.Longwall instability leads to extrusion of rock mass into an open space. This effect is mostly referred to as a bump, or a rock burst. For bumps to occur, the rock has to possess certain particular rock burst properties leading to accumulation of energy and the potential to release this energy. Such materials may be brittle, or the bumps may arise at the interfacial zones of two parts of the rock, that have principally different material properties.The solution is based on experimental and mathematical modelling. These two methods have to allow the problem to be studied on the basis of three presumptions: – the solution must be time dependent – the solution must allow the creation of crack in the rock mass – the solution must allow an extrusion of rock into an open space (bump effect)

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