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1

A Study of a Protective Container for Combined Blast, Fragmentation and Thermal Effects from Energetic Materials Detonation

Ahmed Khurshid, Malik Abdul Qadeer

Central European Journal of Energetic Materials

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2022

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Vol. 19, no. 2

135--157

EN

A composite protective container is experimentally investigated to counter combined blast, fragmentation and thermal effects from either a 1.0 kg bare or 0.6 kg cased (pipe-bomb) TNT equivalent charge. Commercially available shaving foam was used as the internal filling material. The shaving foam quenched the initial fireball and afterburning reactions. The composite case contained the blast overpressure and prevented the escape of primary fragments. The novel combination of extended polystyrene (EPS) foam, bakelite and polyurethane (PU)-silica composite employed at the container base provided protection against in-contact explosive detonation. Maximum peak reflected overpressure of 86.87 kPa (12.6 psi) was measured at 1.0 m distance for 1.0 kg TNT equivalent charge detonation inside the container. The protective container provided 97% peak overpressure reduction compared to the equivalent surface burst detonation. The fragmentation and their impact on container were simulated using a coupled SPH-ALE approach. Steel casing fragments weighing up to 8.0 g with velocities in the range of 1260-1550 m/s were produced and impacted the container. This investigation provides a basis in the design of a device to combat terrorist devices in public places, high profile meeting venues and transportation systems.

2

Effect of loading characteristics and specimen size in split Hopkinson pressure bar test on high-rate behavior of phyllite

Mishra Sunita, Khetwal Anuradha, Chakraborty Tanusree, Basu Dipanjan

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 4

art. no. e212, 2022

EN

Split Hopkinson pressure bar (SHPB) tests are performed on Himalayan phyllite rock with five different specimen sizes and with different gas gun pressures and striker bar lengths of the SHPB device. The high-strain-rate phyllite parameters investigated are the peak stress, strain at peak stress, dynamic increase factor (DIF), strain energy absorbed, and dynamic modulus. It is observed that the dimensions of the phyllite specimens and the SHPB loading characteristics (i.e., the gas gun pressure and striker bar length) have a strong impact on the phyllite response. Given that SHPB specimen dimensions are small compared to any field rock mechanics problem, the rate-dependent rock mass properties are also determined for each rock using Hoek–Brown criteria. Numerical simluations of the SHPB tests are performed using finite element (FE) analysis in conjunction with the strain rate-dependent Johnson–Holmquist (JH-2) constitutive model to calibrate the JH-2 model parameters for phyllite. The calibrated JH-2 model parameters are dependent on the phyllite specimen size and on the magnitudes of the gas gun pressure and striker bar length. The different calibrated parameters corresponding to different specimen sizes and different SHPB loading characteristics are used to perform FE analysis of a tunnel constructed in phyllite rock and subjected to a blast load. The FE results show that the tunnel responses can significantly differ with strain rate-dependent JH-2 model parameters with difference in the mean stress and vertical displacement at the crown of the tunnel in the phyllite rock as high as 126% and 250%, respectively.

3

Mitigation of blast load risk on reinforced concrete structures considering different design alternatives

Ibrahim Y. E., Almustafa M.

Archives of Civil Engineering

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2020

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Vol. 66, nr 3

225--238

EN

The purpose of this study is to investigate a structure’s response to blast loading when composite columns are used instead of conventional reinforced concrete (RC) cross sections and when a conventional structure is retrofitted with braces. The study includes conducting dynamic analyses on three different structures: a conventional reference RC structure, a modified structure utilizing composite columns, and a modified structure retrofitted with steel braces. The two modified structures were designed in order to investigate their performance when subjected to blast loading compared to the conventional design. During the dynamic analyses, the structures were exposed to simulated blast loads of multiple intensities using the finite-element modelling software, SeismoStruct. To evaluate their performance, the responses of the modified structures were analyzed and compared with the response of the conventional structure. It was concluded that both the structure with composite columns and the steel brace structure experienced less damage than the conventional model. The best performance was obtained through the steel brace structure.

4

Experimental and statistical analysis of blast-induced ground vibrations (BIGV) prediction in Senegal's quarry

Kadiri Imad, Tahir Younès, Iken Omar, Fertahi Saïf ed-Dîn, Agounoun Rachid

Studia Geotechnica et Mechanica

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2019

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Vol. 41, nr 4

231--246

EN

Extractive industries often use explosives to destroy rocks, and productivity requirements tend to increase the charges of the explosives. The blasts induce vibrations, which result in a potential damage of the surrounding structures. Therefore, the prediction of vibrations should be described with accuracy, in order to ensure the safety of engineered structures. However, the prediction of vibrations' levels remain a complicated issue, because it involves numerous parameters correlated to the quarry site. In this paper, statistical analysis based on the peak particle velocity (PPV) and the attenuation law has been carried out to assess the safety charges (Q) for different distances (R) between the blast and the considered structure to secure. Moreover, the experimental investigations were conducted on the quarry site of "Sococim", which is located on the south coast of Senegal. To ensure the safety of the "Conveyor belt" and "Panel 1 (Upper exploitation level)" sites, the PPV should be less than 10 mm/s. In fact, the attenuation model has been used to assess the safe charge weights of the explosive (Q) to be used at the "Conveyor belt" site and at the "Panel 1 (Upper exploitation level)" site. Therefore, the safe charge weights per delay (Q) were respectively 116 kg and 13.75 kg.

5

Evaluation of Pressure Distribution in Buried Pipes with Liquid in the Explosion

Parviz M., Aminnejad B., Fiouz A. R.

Archives of Civil Engineering

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2019

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Vol. 65, nr 3

3--14

EN

In this Paper, a parametric study on pipes buried in soil was performed illustrating the results of blast loading. Effects of various parameters such as the physical properties of water, oil, gas, air, soil, pipes, and TNT have been investigated. The arbitrary Lagrangian-Eulerian (ALE) method was employed using LS-DYNA software. The maximum pressure in a buried pipe explosive was observed at an angle of about 0° to 45° and the minimum pressure occurred at an angle of about 45° to 90°. Therefore, all figures in this study illustrate that fluid pressure levels in buried pipes can help in their stabilization. In generally, by increasing the 1.23 times of liquid density under the explosion, the pressure levels in the soil decreased by 1.3 percent. The gas pressure has been increasing more than oil and water pipes 39.73 and 40.52 percent, respectively.

6

The Influence of the Explosive Ordnance Disposal Suit on the Bomb Squad Safety

Gmitrzuk M., Starczewski L., Szcześniak K., Danielewicz D., Nyc R., Kosmala L.

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2018

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Vol. 9, Nr 2 (32)

27--44

EN

The article presents a study on the influence of shock wave on a Hybrid III anthropomorphic test device (ATD HIII) equipped with an explosive ordnance disposal (EOD) suit. The shock wave was generated by the detonation of SEMTEX 1A plastic explosive, formed in the shape of a 250 g, 500 g, and 840 g sphere, at a distance of 0.5 m, 1 m, and 2 m. The use of ATD allowed for determining parameters of damage to the human body as a result of the impact of overpressure wave. The experiments also included a measurement of such parameters as forces and moments on lower extremi-ties, acceleration of head and pelvis, and forces and moments on a neck simulator. Chest Wall Velocity Predictor (CWVP), calculated from the pressure measured on ADT’s chest, was adopted as the most critical parameter. It was revealed that the allowed distance of explosion of a 500 g pure explosive, which does not cause exceeding the allowed parameters, is 1 m.

PL

W artykule przedstawiono badania wpływu oddziaływania fali uderzeniowej na Antropomorficzne Urządzenie Testowe Hybrid III (ATD, HIII) wyposażone w kombinezon saperski EOD. Falę uderzeniową generowano poprzez detonację z odległości 0,5 m, 1 m, 1,5 m i 2 m plastycznego materiału wybuchowego SEMTEX 1A uformowanego w kule o masie 250 g, 500 g i 840 g. Zastosowanie ATD umożliwiło określenie parametrów uszkodzenia ludzkiego ciała w wyniku oddziaływania fali nadciśnienia. W trakcie eksperymentów mierzono takie parametry, jak siły i momenty na kończynach dolnych, przyspieszenia głowy, miednicy oraz siły, i momenty na symulatorze szyi. Za najbardziej krytyczny parametr przyjęto CWVP (Chest Wall Velocity Predictor – wskaźnik prędkości ugięcia ściany klatki piersiowej) wyliczany z ciśnienia zmierzonego na klatce piersiowej ATD. Wykazano, że dopuszczalna odległość eksplozji czystego ładunku wybuchowego o masie 500 g, który nie powoduje przekroczenia dopuszczalnych parametrów, to 1 m.

7

Walidacja badań eksperymentalnych zjawiska wybuchu z wykorzystaniem metody elementów skończonych

Malesa P., Sławiński G., Bogusz P., Świerczewski M.

Modelowanie Inżynierskie

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2018

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T. 35, nr 66

46--52

PL

W pracy przedstawiono podejście numeryczne do modelowanie zjawiska inicjacji oraz propagacji fali uderzeniowej pochodzącej od wybuchu TNT w aspekcie badań poligonowych. Przedstawiono wyniki analiz numerycznych modeli opracowanych na podstawie badań eksperymentalnych odzwierciedlających warunki badań poligonowych. Symulacje przeprowadzono przy użyciu dwóch algorytmów dostępnych w kodzie obliczeniowym LS-Dyna - podejścia ALE (Arbitrary Lagrangian-Eulerian) oraz funkcji CONWEP. Otrzymane charakterystyki zmiany ciśnienia dla punktów pomiarowych odpowiadających miejscu mocowania czujnika ciśnienia w warunkach poligonowych pozwolą na poprawną walidację badań eksperymentalnych zjawiska wybuchu. Do zrealizowania postawionego zadania wykorzystano oprogramowanie Hypermesh, LS-Prepost oraz LS-Dyna.

EN

The paper presents the results of numerical analyses of models developed based on experimental tests representing the field tests conditions. The paper presents a numerical approach to modelling the phenomenon of initiation and propagation of a wave from TNT explosion in terms of field tests. The simulations were conducted with the use of two algorithms implemented in LS-DYNA code: ALE (Arbitrary Lagrangian-Eulerian) method and CONWEP function. The obtained characteristics of pressure change for measurement points corresponding to the location of pressure sensor fixture in the field tests conditions will allow accurate validation of experimental tests of an explosion phenomenon. Hypermesh programme was applied to accomplish the given task, LS-Prepost to develop a model and analyses the results and LS-Dyna as a solver for conducting the calculations.

8

Resistance of columns

Eamon C., Alsendi A.

Builder

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2017

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R.21, nr 12

66--69

EN

A large strain, large displacement finite element model that allows element separation and failure is constructed and validated based on existing results of reinforced concrete columns subjected to blast loads. In this approach, concrete is represented with the Johnson-Holmquist-Cook model while a plastic-kinematic relationship describes steel behavior. The model is used to predict the capacity of typical reinforced concrete bridge columns to resist an assumed blast load scenario, where changes in concrete strength, steel reinforcement ratio, and axial force on the column are considered. The effectiveness of a method of column protection is investigated, where existing columns are wrapped with a relatively inexpensive steel fiber reinforced polymer (SFRP) jacket. It was found that the use of SFRP can significantly enhance the resistance of the columns.

9

Experimental and numerical study of influence of incidence angle of shock wave created by explosive charge on the steel plate

Barnat W.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2014

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Vol. 62, nr 1

151--163

EN

This paper presents experimental and numerical studies on influence of an incidence angle of the shock wave on a steel plate. The problem of interaction between the wave front and a barrier is important from the point of view of protection the crew of armored vehicles. One way of remedying the harmful effects of impacts of the shock wave is the reflection wave of the barrier set at an angle to the face of the wave. The article presents the numerical and experimental approach to the subject. The numerical part presents four models in which the plate was set at angles 0◦, 15◦, 30◦, 45◦. In each case, the plate was loaded by a wave formed after the explosion 2 kg of TNT. In the experimental part the results are presented from an experiment in which the wave was formed from 2 kg TNT detonation at a distance of 0.4 m in parallel to the steel plate.

10

Usuwanie zadziorów kryształami lodu

Szafarczyk M.

Mechanik

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2013

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R. 86, nr 10

858

11

Analysis of IED sidebar explosion influence on hull of light fighting vehicle

Barnat W.

Journal of KONES

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2013

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Vol. 20, No. 1

7--14

EN

This paper shows preliminary numerical analysis of impact of IED sidebar blast on the hull of the light fighting vehicle in order to meet the current standards. Numerical analysis was carried out using a 3-dimensional shell FE model of the vehicle. The problem of the modelling method and computer simulations required several specific features for applied material models, e.g. physical state, plasticity, crispness, hardness. All necessary material properties were taken from the available literature or they were based on the experimental tests carried out in the Department of Mechanics and Applied Computer Science at the Military University of Technology. The STANAG 4569 is a legal basis that regulates the level of ballistic protection for such vehicles. Companies producing that kind of armoured vehicles for army, constantly look for the best and the newest energy consuming materials to ensure appropriate protection of the vehicle and the crew inside it against the effect of IED blast. The connection between a detonation wave and a formed shrapnel shell after detonation of the IED is created depending on the mass and kind of the charge. It is caused by impulsive load on a side bar or the bottom of a light vehicle. Both, safety of people and equipment endurance, is compatible with main rules that are common in Polish Army and it will be common rule in future. It is the fact that motivates the research centres and the arms industry to develop a product using advance computation method to construct new energy absorbing construction which will increase safety of the crew in the armed vehicle.

12

Determining the effects of discontinuities on blast heap fragment size distribution using a numerical modeling method

Konak G., Ongen T.

Archives of Mining Sciences

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2013

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Vol. 58, no. 1

241--253

EN

There are many factors that determine the size distribution of blast heap fragments. The most important factors are the type and amount of explosive material used and the blast design. However, the geological nature of the work area is also an important parameter. In particular, parameters such as the location and frequency of discontinuities affect the size distribution of heap fragments. The general conclusion reached through laboratory and field studies on discontinuities is that the orientation of the discontinuity and the fillings between the discontinuities determine the blast results. This study presents a numerical model that can be used to determine the relationship between the interval and orientation of discontinuities and blast efficiency. Twelve blast experiments were performed at two quarries to develop a numerical model. The data from the field studies were used as input in the numerical model, and the relationship between the discontinuities and fragment size distribution is investigated in this paper.

PL

Wiele czynników ma wpływ na rozkład wielkości fragmentów skalnych po pracach strzałowych. Wśród najważniejszych czynników wymienić należy rodzaj i ilość użytego ładunku wybuchowego oraz przyjęty plan prac strzałowych. Ponadto, kolejnym ważnym parametrem jest także struktura geologiczna skał w danym terenie, a zwłaszcza rozmieszczenie i częstotliwość występowania spękań i nieciągłości skał mają wyraźny wpływ na rozkład wielkości fragmentów skalnych po wybuchu. Ogólne wnioski wyciągnięte na podstawie badań laboratoryjnych oraz terenowych wskazują, że orientacja spękań i nieciągłości a także obecność wypełnień pomiędzy kolejnymi nieciągłościami w dużym stopniu wpływają na rozrzut wielkości uzyskanych fragmentów skalnych. W artykule przedstawiono model numeryczny który może zostać wykorzystany do określenia zależności pomiędzy orientacją i rozmieszczeniem nieciągłości i spękań a skutecznością prac strzałowych. Model numeryczny opracowano na podstawie wyników dwunastu eksperymentalnych wybuchów w dwóch kamieniołomach. Dane z badań terenowych wykorzystano jako dane wejściowe do modelu numerycznego. W artykule przebadano zależność pomiędzy obecnością spękań i nieciągłości a rozkładem wielkości uzyskanych fragmentów skalnych.

13

3-D simulation of tunnel structures under blast loading

Buonsanti M., Leonardi G.

Archives of Civil and Mechanical Engineering

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2013

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Vol. 13, no. 1

128--134

EN

In this paper we want to study the behaviour of an underground structure subject to blast action. Other than the normal operating loads we considered the actions generated by a thermal gradient simulating the action of a fire load and by a pressure wave simulating an explosion. Initially the theoretical aspects of the problem were exanimated, and then a model was developed in numerical form and implemented through a finite element analysis. This modelling allows the simulation of a real scenario, e.g., railway tunnels with reinforced concrete structure that is subject to a fire generation and a subsequent explosion. The simulation involved aspects of thermal analysis, and therefore the structural problem was tackled analysing the tensions in the structure generated by the effect of temperature–pressure generated by the fire and by the overpressure generated by the blast. Only following this approach the most important factors influencing the dynamic response and damage of structure can be identified and the appropriate preventive measures can be designated.

14

Numerical simulation of blast resistant steel plate strengthened with composite

Kosiuczenko K., Niezgoda T., Barnat W., Panowicz R.

Journal of KONES

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2011

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Vol. 18, No. 3

155-160

EN

The paper presents the process of enhancing blast resistance of a thin steel plate by reinforcing it by a composite. The composite consisted of five differently orientated layers of high resistant S2/Glass fabric. Such system was subjected to a pressure wave generated by detonation of small TNT charge placed at a certain distance from the plate. Reinforcing the plate with composite layer improved the ballistic and blast wave protection level of the shield. Due to the usage of the composite the overall mass of the entire plate raised only slightly. Proposed solution can be used to improve the characteristics of existing armours by adding extra panels or modifying armours of transport vehicles. For the purpose of the numerical analysis, the Finite Element Method and explicit time integration were used. Calculations were done using LS-Dyna software. Numerical solutions of both steel plate and steel plate with composite are presented and evaluated. Pressure wave of the blast impulse, the physical model of the blast test, Structure of the four composite layer, deformation shape of steel-composite plate (pressure wave in Z-direction, t=1 ms), failure of plies, Huber-Mises-Hencky stress as material effort on plate are presented in the paper.

15

Morfologiczna ilościowa ocena dynamiki zmian w błonie śluzowej jelita cienkiego po doświadczalnym urazie z podmuchu

Sapieżko J., Siermontowski P., Kozłowski W., Koktysz R., Sapieżko S., Olszański R.

Polish Hyperbaric Research

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2006

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Nr 1(14)

49-58

16

Zastosowanie techniki MIMO w systemach radiowych B3G

Dziunikowski W., Wągrowski M.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2005

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nr 2-3

60-67

PL

Przedstawiono aktualnie prowadzone prace w zakresie zastosowania technik MIMO i MISO w systemach radiowych B3G. Opisano koncepcję MIMO oraz rozwiązanie typu BLAST. Scharakteryzowano prace badawcze związane z tym zagadnieniem, prowadzone w ramach 5. oraz 6. Programu Ramowego. Przedstawiono stan prac standaryzacyjnych związanych z wdrożeniem techniki MIMO w bezprzewodowych sieciach lokalnych oraz sieci UMTS, a także dostępne rozwiązania komercyjne.

EN

This article presents an overview of research activities concerning the deployment of MIMO and MISO systems in B3G wireless communications. At first, a concept of MIMO and BLAST solution is presented. Next, projects regarding this concept, funded by European Union in the 5th and in the 6th Framework Program are shortly characterized. Additionally, the state-of-the-art of standardization work regarding the utilization of MIMO systems in wireless local area networks and UMTS network, as well as, commercial solutions are presented.

17

Oddziaływanie podwodnej fali uderzeniowej na organizm płetwonurka i załóg okrętów podwodnych

Sapieżko J., Siermontowski P., Koktysz R., Olszański R.

Polish Hyperbaric Research

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2005

|

Nr 4(13)

7-15

PL

Celem pracy jest przedstawienie własnych doświadczeń na podstawie przeprowadzonych badań oraz danych z piśmiennictwa światowego na temat urazotwórczego wpływu podwodnej fali uderzeniowej, generowanej przez detonację materiałów wybuchowych, na organizm płetwonurka oraz załóg podwodnych obiektów pływających. W pracy omówiono fizyczną charakterystykę wybuchu oraz fali uderzeniowej. Szczególną uwagę zwrócono na patomechanizm i patofizjologię obrażeń spowodowanych falą uderzeniową (FU). W podsumowaniu przedstawiono kliniczny obraz obrażeń spowodowanych podmuchem, ich różnorodność i skomplikowany charakter oraz związane z tym trudności w udzielaniu pomocy poszkodowanym. Szczegółowo omówiono, na podstawie dostępnego piśmiennictwa, przyczyny i patomechanizm tzw. nagłej śmierci po wybuchu u członków załóg obiektów podwodnych.

18

Determining optimum volume of cold and hot blast air in single--row coke cupolas

Khatemi B., Longa W.

Metallurgy and Foundry Engineering

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2005

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Vol. 31, No 1

53-65

EN

In this study a formula was derived to calculate optimum volume of cupola blast air [formula), standard operating conditions], cold or hot, for single-row coke cupolas, assuming that the lower boundary of the melting zone is adhacent to the upper boundary of the combustion zone (the condition of optimum cupola running formulated by A. Achenbach in 1931). Relevant equations and tables have also been developed to make the calculations easier. From computations made in this study it follows that the optimum blast air volume is increasing with an increase of the blast air temperature, assuming for cold blast a value close to [formula] (Buzek postulate), with modulus of the metallic charge lumps changing in a range of 15 to 20 mm.

PL

W pracy wyprowadzono wzór do obliczania optymalnej ilości powietrza dmuchu [wzór), warunki normalne], zimnego lub podgrzanego, dla żeliwiaków koksowych jednorzędowych, przy założeniu, że dolna granica strefy topienia przylega do górnej granicy strefy spalania (warunek optymalnego biegu żeliwiaków, sformułowany przez A. Achenbacha w 1931 roku). Opracowano również wzory i tablice ułatwiające obliczenia. Z przeprowadzonych obliczeń wynika, że ze wzrostem temperatury powietrza dmuchu rośnie optymalna ilość powietrza dmuchu, przy czym dla zimnego dmuchu oscyluje ona około wartości [wzór] - postulat Buzka, przy zmianie modułu kawałków wsadu metalowego w zakresie od 15 do 20 mm.

19

Prognozowanie wpływów robót strzałowych prowadzonych w górnictwie odkrywkowym na środowisko

Modrzejewski S.

Górnictwo Odkrywkowe

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2004

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R. 46, nr 5/6

35-42

PL

Przedstawiono główne czynniki zagrożenia środowiskowego od robót strzałowych. Scharakteryzowano poszczególne rodzaje oddziaływań oraz podano metody wyznaczania granic stref bezpieczeństwa ze szczególnym uwzględnieniem ochrony obiektów kubaturowych. Określono sposoby i wytyczne ograniczania zagrożeń od drgań sejsmicznych, rozrzutu i podmuchu w kontekście eliminacji szkód górniczych. Opracowano zależności propagacyjne umożliwiające zidentyfikowanie związków przyczyno-skutkowych w układzie działalność górnicza a uszkodzenia obiektów.

EN

The paper presents main risks for the environment caused by shot-blasting work. Specific types of impact were presented, and methods of determination of safe zones were outlined, with a special focus on protection of buildings. The author defined methods of and guidelines for limitation of risk caused by seismic vibrations, dispersion and blast in respect of elimination of mining damage. Propagation dependencies were determined in order to identify the cause-and-effect relations between the mining activity and damage f' buildings.