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By Eduardo Lozano, Vilem Petr

The use of explosives brings countless benefits to our everyday lives in areas such as mining, oil and gas exploration, demolition, and avalanche control. However, because of the potential destructive power of explosives, strict safety procedures must be an integral part of any explosives operation.

Jan 1, 2017

By S. M. Geerts, M. T. Wild

In this paper the performance effects of various shaped charge liner designs will be discussed. Several different charges will be tested and the liner design will be reviewed based on the performance in testing. The first type of shaped charge to be tested is a conical charge with dual confinement. For the purpose of this paper, dual confinement is a shaped charge with two liners but containing one explosive charge. Several charges with different dual confinement designs will be tested. Variations in configuration include charges with similar angle and similar diameter. The second type is a double conical shaped charge configuration. A double shaped charge will be considered to be two complete charges formed into a single cone. The goal of the project is to determine if any of the designs increase the efficiency and/or effectiveness of the shaped charge in comparison to the standard conical shaped charge. A standard conical charge will be detonated against a witness plate to get a standard depth of penetration or a baseline. All charges will have a seven cone diameter standoff, allowing the data to be compared to the control charge. Computer modeling will be used to predict the results of the testing that will be conducted. The actual results will be compared to the computer simulation for validation.

Jan 1, 2010

By Gloria Contreras

The study aims to optimize the density of holes per tunnel section. The energy distribution, the one with the highest density, is used in the center of the diagram and is distributed homogeneously towards the contours with the lowest energies up to the contours to produce a perimeter control.

Feb 1, 2020

By Daniel Castelo, Ben Potter

This paper will discuss the most efficient and effective way to use shape charges when considering standoff distances and the amount of an explosive to be used. For each shape charge test that was performed, a one inch diameter copper liner of 90o was used. Different standoffs for each shape charge were tested to see which one would penetrate the deepest into rolled homogenous armor steel (RHC 44). It was determined that a standoff of three cone diameters provides the deepest penetration. In addition to testing for optimal standoff distances, the effects of overfilling as well as under filling a shape charge with explosive was tested against a shape charge with the bare minimum amount of explosive for correct detonation. These “fill” tests were all performed at a standoff of three cone diameters. Overfilling has little to no effect towards penetrating deeper into a target while under filling a shape charge has an effect of shorter penetration. C-4 explosive was the main explosive for all shape charges.

Jan 1, 2011

By William Adamson

Precise and data driven methods of predicting and modelling blast induced vibration intensity are created and applied under field conditions on a routine basis today. These models are fed with controlled field measurements of vibration pulses generated by controlled charges under known geometric conditions. With such models blasting and geomechanical engineers can estimate vibration intensity at established critical points in mine bench geometry (surface mining) as well as within semi-permanent crown and rib pillars (in underground mining).Damage to bench walls and destabilization of large-scale geomechanical structures can be partially attributed to high intensity blast induced stresses on the rock mass and structures that define important features such as safety catch berms and haul roads. In the underground environment, weakening of critical pillars in block caving or Long Hole Open Stoping(LHOS) operations may lead to ore sterilisation. Blast vibration intensity can be linked with physical alteration in critical rock mass volumes within themine. Often the potential for vibration damage is estimated by the calculation of a critical value of vibration intensity, derived from a consideration of laboratory measured rock matrix properties. Efforts to confirm the accuracy of these estimates of critical vibration level include post blast excavation photography as well as the visual examination of rock mass, pre-and post-blast, using video camera observation of the walls of purpose drilled observation holes. These methods clearly indicate a change in fracture state due to the blast induced vibration, however further modelling of geomechanical stability will benefit if seismic measurement data can be interpreted in terms of geomechanically relevant strength parameters. This paper describes some of the results of previously unpublished research studies conducted in underground operations in Chile and Australia, where cross-hole seismic measurement profiles were interpreted in terms of dynamic modulus. This work dates from a period between 1987 and 1990 and the Author suggests that 30 years on, applying modern day technology, instrumentation and modelling methods, more meaningful, practical and applicable results may be obtained.

By Yessica Idrogo

"Undoubtedly mining is currently the activity that brings a great development for all countries involvedin this industry, which means that to develop mining requires adequate explosive mixtures. The following work about AL/AN/FO is presented, knowing that this is a dry blasting agent, which iscomposed by ammonium nitrate, petroleum diesel N°2 and aluminum (AN, FO, AL). It is known that this dry blasting agent AL/AN/FO was invented by A. Baver Ph. D. in Marcona Mining Company, 12/12/1968, where in that investigation also worked Carlos Agreda Ph.D. as assistant of the mentioned inventor."

Jan 1, 2017

By Christodoulos Xiouris, Ali Reza, James Karnesky

A rocket parachute signal flare is often used to signal a maritime emergency. In the general operation of these devices, a solid rocket motor propels a metal body to an altitude of approximately 1000 ft (305 m). At the end of the rocket motor, a propelling charge drives a signal flare and parachute out of the metal body and ignites the flare, which then burns for approximately 40 seconds as it falls to earth. In this paper, we describe an engineering investigation of an accidental ignition of a rocket parachute signal flare, which caused injury to the user. T

Feb 1, 2020

By Christodoulos Xiouris, Ali Reza, James Karnesky

A rocket parachute signal flare is often used to signal a maritime emergency. In the general operation of these devices, a solid rocket motor propels a metal body to an altitude of approximately 1000 ft(305m).At the end of the rocket motor, a propelling charge drives a signal flare and parachute out of the metal body and ignites the flare, which then burns for approximately 40 seconds as it falls to earth. In this paper, we describe an engineering investigation of an accidental ignition of a rocket parachute signal flare, which caused injury to the user. The components of the flare involved in the accident were inspected via x-ray and microscopic imaging techniques, and compared with those of unfired flares recovered from the same vessel. Chemical analysis of residue on recovered components from the accident flare was also performed. These comparisons were used to determine the likelihood that the actuation mechanism had been deliberately manipulated. In the subject model of the flare, ignition of the rocket motor is accomplished through a percussion cap which is struck by a firing pin. Prior to activation, the firing pin holds down a pre-compressed spring. We present a comparison of the ignition system of the incident flare with those of other rocket parachute flares, which do not incorporate any stored mechanical energy.

By Roger Favreau, Patrice Favreau

Without blasting there can be no roads, no hospitals, no factories, not even foundations for homes. Yet in 1960 the only way to design a blast was by trial/error. By comparison, bridges were already designed by calculations before being actually built. This was possible because equations based on the fundamental principles of science existed with which all the stresses in the bridge could be calculated. In 1960 no equations based on the fundamental principles of science existed with which the mechanisms that take place inside the rock mass during a blast could be calculated. Since then the main author made it the objective of his research to seek such equations, and to validate that they gave accurate answers by means of experiments in the field, experiments made in co-operation with mines, quarries and the explosives industry; results have been reported in some 90 publications.These equations now deal with essentially all aspects of a bench blast: the intensity of the shock wave and the fragmentation size distribution throughout the rock mass; the movement of all the fragments into the muck pile; the fly rock and vibrations from the blast; etc.; are presented examples of such equations. They are now assembled into a computer simulator called Blaspa accessible on the Web, with which one can design a blast just as a bridge is designed. An example is presented. The reason to design a blast by simulations rather than solely by trial/error is that if it leads to damage, it is only after the actual blast that the blast design is realized to cause damage. If however the blast design had been simulated before the blast, then the risk of damage is identified before the blast and is prevented by redesigning the blast. Examples of such situations are presented. The need to a void damage is very necessary because the public is becoming opposed to blasting. When a blast does cause damage, and people learn that the blast was designed solely by trial/error even though simulation was available and would have prevented damage, they become even more strongly against blasting; they may succeed in getting a quarry closed. Their objections to unchecked blasting are not unreasonable, especially as simulating a blast with Blaspa on the Web is a very simple procedure.

Jan 1, 2013

By M E. Hanson, K Chong, R H. Jacobson, S C. Way

To create conditions for economic rates of mineral recovery in a deep, hard rock mass, enhancement of naturally occurring permeability is necessary, and may be achieved through explosives detonated in boreholes. Previous theories of explosively created permeability are reviewed and found to relate permeability solely to the degree of fracturing, neglecting porosity. A theory is presented that includes both fracture density and porosity, and its results are applied, together with a knowledge of explosive behavior, to derive design parameters for in-situ mining.

Jan 1, 1983

By William R. Adamson

This paper describes some of the results of previously unpublished research studies conducted in underground operations in Chile and Australia, where cross-hole seismic measurement profiles were interpreted in terms of dynamic modulus. This work dates from a period between 1987 and 1990 and the Author suggests that 30 years on, applying modern day technology, instrumentation and modelling methods, more meaningful, practical and applicable results may be obtained.

Feb 1, 2020

By Wawa Jaka Sungkawa, Slamet Rachman Jaka, Tom Dermody

A project was undertaken to research and develop a method to confidently predict vibration. It was decided that the scaled distance formulas were not adequate to predict vibration when using non-electric detonators, as accurate wave propagation could not be achieved. The problem is how to manage of complex geology condition related with wave propagation in ground vibration control. Geological condition mapping with specific spatial range can and combine with Signature Hole Analysis be a solution to make wave propagation easier to accommodate in ground vibration control

Feb 1, 2020

By Per-Anders Persson

TIGERWIN, now on CD, is a user-friendly personal computer code (running under Windows) which determines the detonation and expansion state of an explosive from its known chemical composition. TIGERWIN is intended for users in the mining and commercial explosives industry who do not routinely program or run Fortran codes. The code allows the user to open a window on the computer screen and enter the initial density and the weight percentage composition of an explosive, ingredient by ingredient. Alternatively, the code can balance the composition with one or more ingredient percentages fixed, while proportionally adjusting the others automatically to give a total of 100%. The equation of state and its parameters can be user-selected from several proven and tested versions of the BKW, the JCZ, and the ideal gas equations of state. TIGERWIN allows the user to select several options for different additional calculations, such as determining the constant volume explosion, the Chapman-Jouguet (C-J) point, the detonation Hugoniot, the expansion isentrope from the C-J point, and point calculations with selectable specific volume and temperature. Additional options include calculations of detonation data with one or more ingredients partially reacted, assuming either temperature equilibrium between reaction products and unreacted material, or keeping the unreacted material “cold” at the initial temperature. Thus the code can run both ideal and non-ideal detonation calculations. The code automatically saves the input and output files in a separate directory for future reference. The output from several calculations can be displayed and printed in the form of a comparison table. In it, the key results of up to five calculations with different explosive compositions can be compared. The results from an individual calculation can be displayed graphically and printed with expansion work, pressure, or temperature as functions of specific volume. A complete listing of the details of the calculation results, similar to those from the original Fortran Tiger calculations, can also be displayed and printed. No computer experience is required to run the code and workshop participants are encouraged to bring in their own formulations to try out on TIGERWIN

Jan 1, 2000

By Calvin Konya, Anthony Konya

Presplitting is a form of blasting that when executed properly will create a smooth wall that will minimize secondary conditioning. In recent years, presplitting has become a popular technique to be used in both the mining and construction industries, however, presplitting fails on many occasions because of ‘geologic conditions’. This is typically because of improper explosive loads consisting of overloading and underloading blastholes. In this paper the authors introduce new factors such as a presplit factor which varies for different rock types, selection criteria for the spacing of presplits, and the optimization of explosive load for the technique of Precision Presplitting.

Jan 1, 2017

By Uli Leiste

Two papers are presented which examine Air Deck Blasting, one from a computational aspect and the other from a shock aspect.

Jan 1, 2016

By Ben Barrett

Dangerous goods, known as hazardous materials in the USA, are subject to special controls during transport to ensure the safety of the public. Dangerous goods are divided into nine classes, and Class 1 is devoted to explosives. Unlike storage or manufacturing, explosive transportation crosses the political boundaries of localities and nations, and its regulation must be centrally managed to avoid duplicate costs of complying with multiple regulations. Additionally, the transport of dangerous goods occurs by four different modes – highway, rail, vessel and air. While each mode has differences which must be addressed, the fundamental principles of classification, packaging, hazard communication and documentation remain the same. When a shipment travels by multiple modes and across borders, consistent regulations become paramount to cost efficiency. This is a common occurrence in the growing global economy.

Jan 1, 2010

By Sami Kara, Marsel Nabium

This paper provides an overview of the solution applied in underground Silver mine in Russia. The paper reviews the dilution problem throughout the entire mining process, and provides a rational approach to underground mine Blast design in order to minimize dilution

Feb 1, 2020

By Thierry Bernard

To be able to precisely predict the result of a mine blast before pressing the button is a goal for many blasters due to the environmental and economic constraints of our century. Based on the fundamental fracturing of the mechanism of rocks by explosives, the most recent research in digital modeling, the power of present computers, and the possibilities offered by drones, we have designed a realistic digital 3D simulation model for mine blasts

Feb 1, 2020

By Jacob Miller, Phillip Mulligan

"Measuring the blast pressure associated with an explosion suspended above the ground (Free Air Burst)is a common research objective in Explosive Engineering. Theoretically, the shockwave from a Free Air Burst (FAB) configuration expands radially and the shockwave is assumed to have a smooth (uniform) shock front. The way in which the FAB explosive charge is suspended, packed, and the charge geometry can affect the shockwave expansion. These factors can generate a non-uniform shock front. As the scaled distance between the pressure sensor and the FAB increases, the shockwave expansion averagesnon-uniformities into a uniform shock front, at which point the FAB suspension system becomes less critical than when the scaled distance is “close-in” (Z <3)."

Jan 1, 2017

By J. Eloranta

"Previous work indicated that the annual per-capita consumption of raw aggregate material averages about 10 tons; half of which is produced by blasting. Given a population of approximately 320 million in the United States alone, this amounts to 1.6 billion tons of blasted material annually. It was also estimated that up to 20% of the blasted material in aggregate operations is smaller than 6.35 mm (1/4inch) in size. Thus, about 320 million tons (i.e. 1 ton per capita) of byproduct is produced annually and sold at significantly lower prices or potentially discarded in waste dumps."

Jan 1, 2017