Assessment of blast effect open pit,”Ranci’’ of shock waves on constructed facilities and environment

The blast effect problem of shock waves is growing in the area surrounding blasting activities. In addition to damage shock waves may cause on buildings and mining site facilities, they also impact badly human force there, namely the environment. Lately considerable research in the world has been dedicated to the examination and numeric modelling of this phenomenon. Specific standards have been established defining the blast effect margin level of shock waves on facilities and human force there. Numerous numerical and empirical models have been developed to predict and monitor them. In Serbia, there are no standards for the assessment of blast effect of shock waves. This paper deals with the assessment of blast effect of an open pit mine and specific conclusions that have been drawn

Investigation of quantitative indicators of anisotropy based on longitudinal elastic waves propagation velocities with uncertainty

Almost all of rock masses are more or less anisotropic medium. Foliation, layering, cracking and cleavage are some of the rock attributes that indicate to anisotropy presence. Due to the existence of these discontinuities, elastic waves propagation velocities along certain directions are extremely different. In this paper, we investigated total of 50 samples which are divided into two groups of samples, isotropic and anisotropic samples. Longitudinal elastic waves propagation velocities are measured in the three normal directions and three orthogonal planes, respectively. The main scope of this study is related to interval numbers in order to express uncertainties of the longitudinal elastic waves propagation velocities. Based on this, we have determined quantitative indicators of anisotropy. Obtained results are represented in graphic form

Functional dependence on construction costs of horizontal mining facilities in lead-zinc ore

Horizontal mining facilities, such as pits, crosscutting drifts, longitudinal drifts etc., can be constructed in surrounding rocks, underburden or usually overburden, also in the ore deposit. The route of horizontal mining facilities primarily depends on: physical and mechanical properties of surrounding rocks and ore deposits, as on the thickness and way of providing the ore body, the construction costs and the projected mining method. It should be noted that within same types of rock exist zones with different structural characteristics, regardless where mining facilities will be constructed either in surrounding rocks or ore body. Different properties create a difference in stability of the rock material. Therefore, is essential for any rock type to determine its structural properties such as: discontinuity plane orientation, the degree of jointed on rock material, joint and joint family, as and stability of each block, located adjacent to underground facilities

Analysis of Rock Mass Oscillation Law With Review of Reduced Distance

Explosive energy, by its form, has destructive, devastating character, but nowadays the implementation of chemical explosive energy is highly advanced in order to meet human needs. There have been developed numerous activities in the world whose work cannot be imagined without explosive energy implementation

Contribution to improvement of the legalization of the work process of small-scale mines in the Republic of Serbia

In this study we focus our attention on the procedures of obtaining necessary permits for the opening of a mine. Our goal is during those conditionally speaking first steps in the process of activating a mine to point to the attention of the reader to the complexity of that process, as well as excessive administrative work when permits for small-scale mines are in question

Parameter determination of soil oscillation law using quotient of the relative growth increments of oscillation velocity and reduced distances at 'Nepričava' Open Pit Mine

During blasting operations, the potential energy of explosive materials is transformed into a mechanical work. That energy, in the vicinity of blasting location, destructs and crushes rock mass, a bit further creates cracks and permanent deformations in the rock mass, and even further it is being transformed into elastic deformations. The effect of elastic seismic wave is movement of particles of the rock mass from its equilibrium position. Such oscillation of the rock mass particles is manifested as a shock and represents one of the negative effects of blasting. In order both to evaluate and control the seismic effect of blasting, as well as to plan it, the determination of soil oscillation law is required, with the strike: mine field - facilities to be protected. One of the most commonly used equations is that of M. A. Sadovski defining the law of alteration in the oscillation velocity of the soil depending on the distance, the explosive amount, and conditions of blasting and geologic characteristics of the soil, being determined on the basis of test blasting for the specific work environment. In this paper, an analysis of the method for the determination of soil oscillation law parameters has been conducted, suggested by Professor M. A. Sadovski. The applicability of this law was analyzed on examples of mass blasting in the 'Nepričava' Open Pit Mine being carried out in order to exploit the deposit. To determine parameters in the equation of Sadovski, in addition to the common method of least squares, another model was applied. Thereby, it has been stated that both models can be used to calculate the oscillation velocity of the rock mass

Functional dependence on construction costs of horizontal mining facilities in lead-zinc ore

This paper presents a methodology for determination of the two parameter dependence on construction costs of horizontal mining facilities in the lead-zinc ore. Construction costs are shown as a function of the profile area on facilities and the degree of jointed on the rock, presented by the change in their uniaxial compressive strength

Foliation impact on the dynamic properties of selected samples of the barrier dam site Prvonek: Right side

The 'Prvonek' dam was built in tight asymmetric Banjska river valley about 100 meters downstream from the river Gradasnica. Barrier at the dam site built predominantly slate series of high crystallinity Vranjska Banja, alternately layered double mica, gneiss, leptinolite and micaschist. For the construction of this place were carried out extensive field and laboratory geotechnical investigations. Part of laboratory geotechnical investigations related to the testing of dynamic properties in the perpendicular and parallel direction to the foliation of gneiss and micashist samples on the right side. The aim of investigations is definition of anisotropy tested dynamic parameters

Steel Arch Support Deformations Forecast Model Based on Grey–Stochastic Simulation and Autoregressive Process

Relatively large deformations of the steel arch support in underground coal mines in the Republic of Serbia present one of the main problems for achieving the planned production of coal. Monitoring of the critical sections of the steel arch support in the underground roadways is necessary to gather quality data for the development of a forecasting model. With a new generation of 3D laser scanners that can be used in potentially explosive environments (ATEX), deformation monitoring is facilitated, while the process of collecting precise data is much shorter. In this paper, we used a combination of grey and stochastic system theory combined with an autoregressive process for processing collected data and the development of a forecasting model of the deformations of the steel arch support. Forecasted data accuracy based on the positions of the markers placed along the internal rim of support construction shows high accuracy with MAPE of 0.2143%. The proposed model can successfully be used by mining engineers in underground coal mines for steel arch support deformations prediction, consequentially optimizing the maintenance plan of the underground roadways and achieving planned production

Novel Hybrid MPSI–MARA Decision-Making Model for Support System Selection in an Underground Mine

An underground mine is a very complex production system within the mining industry. Building up the underground mine development system is closely related to the installation of support needed to provide the stability of mine openings. The selection of the type of support system is recognized as a very hard problem and multi-criteria decision making can be a very useful tool to solve it. In this paper we developed a methodology that helps mining engineers to select the appropriate support system with respect to geological conditions and technological requirements. Accordingly, we present a novel hybrid model that integrates the two following decision-making components. First, this study suggests a new approach for calculating the weights of criteria in an objective way named the Modified Preference Selection Index (MPSI) method. Second, the Magnitude of the Area for the Ranking of Alternatives (MARA) method is proposed as a novel multi-criteria decision-making technique for establishing the final rank of alternatives. The model is tested on a hypothetical example. Comparative analysis confirms that the new proposed MPSI–MARA model is a very useful and effective tool for solving different MCDM problems