Witold M. Pytel

• Professor
• KGHM CUPRUM R&D CENTER, Wrocław, Poland

A simplified analytical method useful for ductile ground support design in underground mine workings is presented. This approach allows for maintaining the stability of sidewalls in rectangular openings extracted in competent and homogeneous rocks, especially in high-pressure conditions, favoring rockburst event occurrence. The proposed design proc...

Roof falls are currently one of the most dangerous threats associated with underground mining at great depth. Every occurrence of such an event poses a significant risk to the mining crew and disturbs the continuity of the mining process, which clearly affects the economy of the exploitation process. The development of a reliable monitoring system...

A roof fall hazard is still one of the major threats in the underground mining industry. Each such type of event always brings great risk to miners and causes serious interruptions in the process of rock excavation. In general, the possibility of roof fall hazard occurrence is directly related to the local geology, the presence of horizontal stress...

In this paper, selected methods of destress blasting efficiency assessment are presented, and novel quantitative methods based on in situ seismic measurements are proposed. The newly formulated solution combines two different approaches. The first, which is useful mostly for the near-field seismic analyses, is based on the analysis of seismic ampli...

Multi-face blasting is one of the most frequently used active rockburst prevention methods in the Polish copper mines. Simultaneous firing of a group of faces generates vibrations which, propagating in the form of para-seismic waves, affect the condition of the rock mass structure and allow to trigger high-energy tremors during the production proce...

The classical Rayleigh surface rotational wave in terms of its theoretical notation and, resulting from this, properties associated with the induced seismic phenomena in mines are presented. This kind of seismic wave was analysed in-depth from the point of view of the parameters governing the form of its mathematical notation based on the similarit...

The article discusses geomechanical aspects and numerical simulations associated with the mining methods dedicated for flat or flatly dipping orebody, i.e. room-and-pillar and longwall mining systems with regard to development of hypothetical mining panel. It was assumed that the overburden strata consists of several homogeneous rock plates reflect...

The impact of seismicity on structures is one of the key problems of civil engineering. According to recent knowledge, the reliable analysis should be based on both rotational and translational components of the seismic wave. To determine the six degrees of freedom (6-DoF) characteristic of mining-induced seismicity, two sets of seismic posts were...

Underground laboratories provide a unique environment for various industries and are the perfect place for developing new technologies for mining, geophysical surveys, radiation detection as well as many other studies and measurements. Unfortunately working in underground excavations is associated with exposure to many hazards not encountered in th...

The biggest risk to operations in Polish copper is high-energy seismic tremors where hypocenters are located within the main roof strata. These phenomena occur often in the areas which are virtually free of tectonic disturbances. They are extremely difficult to both predict and analyze due to their short duration and unpredictable time of occurrenc...

One of the major problems associated with the excavation of the copper deposits in underground mines in Poland is the relatively high level of seismic activity. Numerous high-energy tremors can negatively affect the stability of underground workings and can have a destructive impact on the infrastructure located at the surface as well. As predicted...

Mining-and-industrial heritage-underground workings, open areas of former mining works, natural caves and underground cavities are, as a rule, in critical condition and pose safety threat to the tourists visiting those. On the other hand, such places, having historical, technological and landscape value, are major assets for the development of tour...

Based on the finite element method formulated in three dimensions, a selected area of the salt mine has been modeled, embracing totally 2 separated, historically valuable mine rooms. The results of the computer simulations permitted elastic-viscous rock mass stability analyses identifying the areas being more susceptible to damage, presently and in...

In this paper, a multiscale modelling and simulation of destress blasting of rock mass is presented. .e proposed and novel approach combines two separate 3D solutions: the first was obtained for the small-scale problem, face(s) blasting process, and the second for the global scale problem, seismic wave propagation within very large volumes of surro...

Antropogenic seismicity is one of the most important geomechanical hazard encountered in Polish deep copper mines. Obviously, it may have a negative impact on the peoples safety and the production process. In such circumstances, a number of both active and passive prevention measures have been implemented in the mines, at least partially. One of th...

The exploitation of copper ore deposits in Polish underground mines is performed primarily by the use of blasting technology which seems to be relatively well suited to the hardness of the local rocks and to local mining and geological conditions. Blasting works are also recognized as an active method of seismic events prevention, conducted as grou...

Extraction of the copper ore deposit in the Legnica-Glogow Copper Basin in Poland is usually associated with high seismic activity. In order to face this threats, a number of organizational and technical prevention methods are utilized, from which blasting works seem to be the most effective. A significant number of recorded dynamic events may be c...

One of the major problems associated with exploitation of the copper ore deposit in underground mines in Poland is the local disturbance in a state of stable equilibrium manifested in a sudden release of strain energy stored in the deformed rock mass. It occurs mainly in the form of dynamic events which may result in rockbursts and roof falls. In o...

The biggest risk to operations in Polish copper is high-energy seismic tremors where hypocenters are located within the main roof strata. These phenomena occur often in the areas which are virtually free of tectonic disturbances. They are extremely difficult to both predict and analyse due to their short duration and unpredictable time of occurrenc...

One of the most serious hazard in the underground copper mining in Poland is the roof fall hazard. The scale and intensity of this type of events depends on several factors. Due to seismic activity, weaker roof strata can loosen and deform, generating additional load on the rock bolt support. The type of load depends strictly on the course of strat...

Having increasingly tightened geological and mining conditions in which the extraction of copper ore deposits in Poland is conducted, ensuring effective and safe mining is presently becoming a key task and a significant challenge for mine operators, mainly in the field of ground support systems being the equivalent for the new geological/mining con...

One of the major problems associated with exploitation of the copper ore deposit in underground mines in Poland is the local disturbance in a state of stable equilibrium manifested in a sudden release of strain energy stored in the deformed rock mass. It occurs mainly in the form of dynamic events which may result in rockbursts and roof falls. In o...

One of the main parameters describing the properties of explosives is the velocity of detonation, which can be defined as the propagation speed of the chemical reaction zone in the detonating explosive. The detonation velocity of an explosive depends on many parameters, such as the material's density or diameter and the shell of an explosive, plus...

Использование подземного пространства в крепких горных породах, после отработки шахт часто вызывают дискуссии об альтернативном использовании оставшейся туннельной системы. Решение заполнить их каменными блоками, бетоном и грунтовыми водами не всегда оптимально, так как эта экологическая работа требует финансовых ресурсов. Альтернативой закрытию яв...

In order to face threats from mining tremors a number of organizational and technical prevention methods are applied in underground mines. Unfortunately, most of these methods are based on the experience of crew and there is uncertainty whether in practice all of the executed operations are suitable and necessary in the given conditions. Analysis w...

One of the problems associated with the excavation of deposit in underground mines is the local disturbance in a state of unstable equilibrium results in the sudden release of energy, mainly in the form of roof falls. The scale and intensity of this type of events depends on a number of factors. To minimize the risk of instability occurrence, conti...

The Lower Silesian Copper District is located in south-west part of Poland and this is one of the most important mining areas in Europe, extracting over 30 million tons of copper ore per year. Copper ore is excavated in three underground mines belonging to KGHM: the Lubin, Polkowice-Sieroszowice and Rudna mines. The stratoidal deposit is characteri...

The risk caused by dynamic effects of rock mass pressure is one of the basic problems associated with exploitation of the deposit in Polish copper ore mines and is mostly represented by tremors, rockbursts and stress relief. These phenomena are extremely difficult to both predict and analyze due to their short duration and unpredictable time of occ...

The article presents the assumptions and a design of the measurement system allowing to observe the behavior of the direct roof based on technologically highly advanced measurement tools in the form of bolts instrumented with strain gauge film. The measuring system uses commonly applied in KGHM Polska Miedź SA 1.8 m long adhesive bolts and the inde...

The exploitation of flat copper ore deposits in Polish deep underground mines is performed primarily by the use of drill-and-blasting technology. Each day in Poland a few hundred mining faces are fired out using this method which seems to be relatively well suited to the hardness of the local rocks and to local mining/geological conditions. Besides...

A major natural hazard associated with LGOM (Legnica-Glogow Copper Mining) mining is the dynamic phenomena occurrence, physically observed as seismic tremors. Some of them generate effects in the form of relaxations or bumps. Long-term observations of the rock mass behaviour indicate that the degree of seismic hazard, and therefore also seismic act...

One of the crucial factors determining the effective burden is an appropriate selection of geometry of cut-holes. Furthermore, leaving empty (uncharged) blasting holes may lead to enlargement of the fractured zone, and thus – improvement of the mining faces blasting effectiveness by means of reducing the number of blasting holes and/or extending th...

The largest risk for mining operations conducted within the Legnica–Głogów Copper Basin is created mostly by high-energy tremors, the hypocenters of which are located within the main roof strata composed of sedimentary-type rocks — mainly dolomite and anhydrite — about 40–200 m above the excavated copper ore body. These categories of rock clearly e...

The main objective of drill-and-blast technology utilized in underground mines is the effective burden development which volume determines ore production. One of the crucial factor affecting the volume of burden is the appropriate selection of geometry of the cut-holes. Because till today there were no available effective analytical tools which wou...

PL:Podstawowym celem stosowania technologii strzałowej przy urabianiu złoża w kopalniach podziemnych jest uzyskanie odpowiedniego zabioru, którego objętość determinuje wprost poziom produkcji. Jednym z kluczowych czynników, decydujących o uzyskaniu właściwego zabioru, jest odpowiedni dobór metryki strzelania, a w tym przede wszystkim geometrii otwo...

Recognition of properties of the rock mass surrounding a mineral deposit is particularly important for the mining operations at greater depths. Since the rock mass is usually not homogeneous, and its parameters have characteristics of randomness, underground workings safety issue should always be analysed taking into account the dispersion of the v...

Numerical experiments modeling different three-dimensional mine layoutwere performed, using two boundary condition sets defined by presence or absence of horizontal additional stress. The determined stress/deformation stateswere used afterwards for quantitative characterization of the effect of horizontal tectonic stress on system behavior. Local r...

The Polkowice-Sieroszowice mine in one of the seven candidates for the future pan-European underground laboratory studied in the framework of the LAGUNA project. We review the evidence that from the point of view of geology, long-term plans for the mine and existing infrastructure, and support of the authorities this is a perfect place to host the...

The feasibility of a next generation neutrino observatory in Europe is being considered within the LAGUNA design study. To accommodate giant neu- trino detectors and shield them from cosmic rays, a new very large under- ground infrastructure is required. Seven potential candidate sites in differ- ent parts of Europe and at several distances from CE...

low background gamma spectroscopy, Underground Laboratory

The feasibility of a next generation neutrino observatory in Europe is being considered within the LAGUNA design study. To accommodate giant neutrino detectors and shield them from cosmic rays, a new very large underground infrastructure is required. Seven potential candidate sites in different parts of Europe and at several distances from CERN are...

A next generation European deep underground neutrino observatory is considered within the LAGUNA design study. Three detector options are presently considered: GLACIER liquid argon Time Projection Chamber; LENA liquid scintillator and MEMPHYS water Cherenkov. It will provide both: the high statistics measurement of neutrinos from variety of sources...

Technical and technological conditions associated with tunnel excavation in soft ground located at the Warsaw shallow subway B-16 line is presented in the paper. Since immediately after construction fracturings of tunnel lining elements, composed of iron cast cylindrical panels, were recorded, research on possible reasons of the damage has commence...

Presented are numerical modeling results concerning the effect of both the face advance rate and the thickness of competent roof stratum on pillars' load and their failure safety factors. The competent roof stratum separates the extremely thick upper salt layer from the room-and-pillar mine workings at a depth of 1,500m. The entire rock mass includ...

The paper discusses the problem of the effect of a rheological layer on the conditions of mining of bedded ore deposit located at a great depth. The assumptions concerning a prospective numerical model employing the finite element method and the finite difference method and the approach for model parameters estimation were also presented.

In the paper, results of roof-pillar-floor system behavior monitoring within selected openings located within one of Polish underground copper mines are presented. Monitoring of deformation of mine workings elements, instrumented with magnet extensometers, instrumented bolts, convergometers and borehole strainmeters, was accepted as an appropriate...

Geological and mining conditions characteristic for the Polish Legnicko–Glogowski Okreg Miedziowy (LGOM) copper mines as well as various exploitation systems utilized in that area are presented. The historical background of mining systems development as well as their classification are also reviewed.Presently, due to difficult mining conditions, a...

Current methods of design of pillars resting on weak floor strata involve only a deterministic, conventional safety factor calculation, based on material parameters treated as the mean values taken from observations. In a case where high parameters variability occurs, these methods may lead to fatal design errors resulting in excessive pillar settl...

This paper develops a rational approach for design of coal pillars under weak floor strata conditions considering ultimate bearing capacity (UBC) as well as pillar settlement. An approximate solution is presented for estimation of UBC for a shallow foundation on a two-layered rock system with consideration of both cohesion (c) and () for both layer...

A method to allow for the shear rigidity in the interaction of structures with subsoil is presented. Closed form solution is given for the case of two-parameter Winkler foundation. On discretization of the system an algorithm is written which can also be used for some more complex foundations. Numerical examples are given.