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By Fred C. Drury

The Explosives Engineer's concern for personnel training in the safe, efficient and effective use of explosives materials has grown in recent years. Available training options have also grown. Today's options include off-site training seminars and in-house training departments, both of which represent significant cost to the smaller producer.

Jan 1, 1981

By Stanley L. Lippincott

A number of Federal and State agencies require formal training for blasters. Federal agencies often specify the need for initial training involving all job responsibilities as well as periodic refresher training to assure adherence to current operating procedures. failure to provide and document such training can result in substantial penalties.

Jan 1, 1995

By Gary B. Hemphill

Each year the demand for precision blasting increases due to the reduction in the amount of prime land. More site preparation and hone building requires blasting than they did a decade ago, Because of this increased need for blasting in more populated areas, the need for blasters and engineers knowledgeable in work involving blasting nets has increased.

Jan 1, 1978

By Calvin J. Konya

When blasts are designed, we normally assume the best case situation. We assume that all burdens and spacings will be properly drilled, holes will be properly loaded, initiators will fire at the nominal time and the explosives will release their full energy. This type of precision can be obtained at a machine shop where precision equipment is available to do machining, however, in the field, no matter how well a blast is designed on paper, it most likely will not be done in the exact manner in the field.

Jan 1, 1990

By Juan Pablo Henríquez, Sebastian Lozano, Constanza Soto, Gonzalo Segura, Carlos Torres, Danko Morales

The Atacama Kozan underground mine, located in Tierra Amarilla, Atacama, Chile, was facing over-excavation and slow progress in drift construction, issues associated with the use of traditional explosive, ANFO. The presence of water in the blast holes required as well the use of cartridged emulsions, which extended loading times and increased operators’ effort. With loading times ranging around 76 minutes and lower advanced rate, Enaex Underground proposed the use of a pumpable emulsion-type explosive to optimize blasting, enhance safety, and streamline the operational process. This explosive is loading into the blasting holes using an UBT equipment (Unidad Bombeable para Túneles in spanish). This equipment allows mechanized loading, adaptation to small and medium diameter boreholes, ensuring compatibility with varying drilling profiles, integration with Atacama Kozan’s operational equipment and improvement in environmental and occupational conditions, with a measurable reduction in contaminant emissions and worker exposure risks. The implementation of this emulsion-based explosive allows an increase in productivity in drift development. A notable effective advance rate of 95% to 96% was achieved, alongside a reduction in overbreak in 7%, and a decrease in loading time to 40 minutes. Additionally, there was a 40% occurrence of drilling half cast, contributing to contour drift quality. The operation also benefited from a cleaner and safer working environment, enhancing operator ergonomics and reducing the need for jetanol and compressed air.

Jan 26, 2026

By Brian Stump, D. Craig Pearson

This work quantifies seismic coupling as a function of charge weight for single-fired (simultaneously detonated) explosions observed in the mine and at regional distances. These single-fired explosions are contrasted to standard production shots from the same mine. Production shots include cast blasts to remove overburden and coal shots for fragmentation. The blasts were conducted in a mine in NE Wyoming. The data sets consist of measurements in the mine (100-10,000 m) and at regional distance (360 km) using a seismic array near Pinedale, Wyoming (PDAR). The single-fired explosions ranged in designed size from 5,500 to 50,000 lbs. Peak amplitudes measured at a single element of the regional array are modeled by a power law relation dependent on explosive weight. Scaling constants were determined for each of the dominant regional phases: b(Pn) = 0.84±0.14; b(Pg) = 0.84±0.09; b(Lg) = 0.91±.08. Spectral ratios of observations from different explosions observed at the same station illustrate the frequency dependnce of the source scaling relations. Spectral ratios of in-mine observations are consistent with those of regional data. The observed single-fired ratios are well replicated by Mueller-Murphy source model ratios. The data and model illustrate both the increase in long-period spectral level and the accompanying decrease in source corner frequency with increasing charge weight. The coal and cast blasts that make up the production shots ranged in size from 77,000 to 4,738,230 lbs. The peak amplitude (1-20 Hz) for the largest delay-fired production shot (4,738,230 lbs.) is comparable to that of the largest single-fired explosion (50,000 lbs.). This comparison can be explained in terms of destructive interference between waveforms from individual boreholes introduced by delay firing. Shot specific models of delay firing suggest that peak amplitudes in this same frequency band for the production shots are insensitive to the total amount of explosives in the blast. Peak amplitude data at regional distances supports his modeling result.

Jan 1, 2002

By Judy Konya Bowles, Calvin J. Konya

Blast vibration and air blast are commonly blamed for damages to residential as well as commercial structures. Mining and construction companies are often required to spend monies in court defending themselves even when vibration and air blast levels have been monitored by seismographs and are extremely low.

Jan 1, 1992

By W. Jiao, Y. Yongqi, R. Shan

Soft rock mines are distributed through out P.R.C. And drilling and blasting is still the main method of driving a tunnel in these mines. Traditional smooth blasting has been widely and deeply studied and put into practice in P.C.R since 1970s. But the cartridge and blast hole are both columns, the stress field in the rock around blast hole at the beginning is symmetry around hole axis, and the original cracks in the rock can be activated randomly. So serious overbreak and underbreak at the boundary of an excavation occur often, especially when the excavation is in soft rockmass, and the rates of half-hole marks are generally about 50% in medium rock, and 20-30% in soft rock in Chinese coal mines. For the sake of overcoming the situation, we have been studying directed crack blasting since ten years, and have got some obvious achievements in this respect. Slotted cartridge control blasting in soft rock is studied in this paper. Through model experiments, reasonable decouple coefficient range and slot width are gotten, and unsymmetrical dynamic strain field is analyzed. Through underground test in soft rock with a strength lower than 1OMpa in Dayan Mining Bureau, The results of which the rates of half-hole marks and the nonsmooth grades of the cut contours are 83.3% and 1OOmm respectively have been achieved.

Jan 1, 2000

By Frank Hammelmann, Peter Reinders

This paper briefly describes the past history of blast management. A modern blast management suite is then presented which demonstrates the current capability of the functional link between an electronic blasting system and blast design software. Finally, we look at the potential of tomorrow’s fully integrated blast management systems. From the first time blasting was introduced in mining as part of the production process, blasting technology and blast management have been interconnected. Over the past decades we have gained more recent experience with the new electronic blasting systems in mining, quarrying and construction. To start, the primary focus of electronic blasting was to increase timing accuracy. However, since then the technology has gradually developed, broadened and opened up new possibilities, including impressive flexibility in blast design and full in-situ verification of system functionality. To support this capability, modern electronic blasting systems are specifically designed to facilitate full two-way transfer of information between the office-based blast management software and field-hardened equipment. Blast management systems now comprise a suite of expert systems for planning, documentation, analysis, measurement and prediction of blasts. Within this blast management suite, the blast design software allows the transfer of the blast design information from a PC directly to the hardware of the electronic blasting system. The future development of this technology holds huge potential for the blasting industry.

Jan 1, 2004

By Jan Mehren, Arild Neby

Underwater Tunnel Piercing or Lake Tap, often also called the Norwegian Method, will in many projects be an important part of the hydro electric development scheme. The very last blasting round in the Lake Dorothy Lake Tap Tunnel, which penetrated into the lake at a depth of 120 ft (36 m), was such a key step in constructing the Lake Dorothy Hydroelectric Project. A lake tap project is multidisciplinary. Besides the pure blasting and construction technique aspect, engineering geological and geometric considerations that aim to optimize the tunnel alignment making a lake tap possible at minimized risk are of significant importance. Output data from numerical model analysis of the hydrodynamics resulting from the blasting is vital for the final adjustments to the geometrical layout. The planning of monitoring systems for the surveillance of hydrodynamic impact on valves and pipes as well as control with water levels and air pressures prior to and during the blasting, are all additional crucial elements in the design. More than 600 lake taps have been successfully performed in Norway since the 1890`s. The technique, which deserves to be called well proven, has been applied mostly in the hydropower sector but over the last 20 years also for shore approaches in the oil and gas industry. The demand for this technique seems to be ever more growing.

Jan 1, 2009

By J. -P. Tshibangu, E. Lefebvre

ABSTRACT : The Tournai’s region in Belgium is characterized by outcrops of limestone that were mined out long ago by different companies for cement and crushed materials. The region is densely populated and the vibrations generated by blasts in the quarries are of big concern. The occurrence of electronic detonators and development of computer sciences brought a new expectation in controlling the vibration level and, hence, carry out bigger blast operations. In this paper we present the results of two experimental blast programs that have been carried out by the Nobel explosive Belgium Company on the Gaurain-Ramecroix quarry to understand the effect of the delay on the vibrations generated in the neighborhood. The first program has been implemented during the early use of electronic caps in Belgium (1996) by performing some unit shots. An attempt to model the effect of the production blasts by the hybrid method (Hinzen 1988) gave promising but poor results compared to infield measurements. A new program (more than ten blasts) has been implemented in 2006 in which the delay and blast firing sequence (i.e. the order in firing adjacent holes in a row) have been changed; a new attempt is made to build unit signals by deconvolution and then try to model production ones. A comparison of the two approaches is made.

Jan 1, 2008

By Alejandro Berrios, Matheus DaSilva, Erick Siqueira

Vazante mine is an underground polymetallic mine that produces zinc, lead, and silver, which belongs to Nexa Resources in Minas Gerais, Brazil. The mine, a sublevel stope underground mine, mainly applies two subvariants: VRM – Vertical Retreat Mining and Open Stope. In a specific place of the mine, the geology allowed the design of a production stope with larger dimensions than the standard stopes, commonly called Super Stope. At this place, the plan was to apply both sublevel variants simultaneously. This mining block comprises rings in two different levels, with access by two ore drives on each level; the dimensions would be approximately 50 meters high, 50 meters long, and 35 meters wide. Opening the Free Face to mine the whole Stope was a challenge due to operational issues, such as hazard risks from loading over void space, exposure to uncontained places, and the impossibility of implementing the optimal blast sequence. Wireless blasting initiators have gained popularity recently due to their convenience, safety, and efficiency. This initiation system was applied to preload all the rings required to open the Free Face, ensuring a safe and optimal blast sequence. Wireless initiation prevented hazard risks, enhanced the blast sequence to guarantee the required void space, and optimized the equipment's operational cycle. The blast crew carried out the activity without exposure to the risk of loading over void space. The wireless detonators also avoided after-blast activities, which were required to provide secure access to the blast crew, optimizing the operational cycle.

Jan 21, 2025

By R. Sibley, K. Perry, E. McCorkle, M. Coy

Black powder has been used in fireworks since the 10 th century in China. To this day, black powder still has a variety of uses, including fireworks, and remains relatively unchanged. Black powder is used in the firework shell to help produce the effect and in the lift charge to propel the shell skyward. The performance of fireworks shells used in displays varies greatly. In fireworks shells, there are two different black powder charges that differ in construction based on the desired performance of the shell. The two charges consist of the lift charge and the break charge. The lift charge is the first to fire and propels the shell out of the mortar. The break charge is the second to fire and is initiated after a delay from the lift charge; its purpose is to burst the shells effect over the desired area of the sky. The lift charge provides the shell with its initial velocity by pressurizing the mortar below the shell body. The pressurization process is violent and occurs in fractions of a second. The purpose of these experiments are to better understand the pressures sustained in fireworks mortars during the firing process. Mortars and shells vary by size and weight. Pressures in each mortar were monitored at various heights along the mortar to provide a pressure profile during shell lift. A high-speed camera was used to measure shell exit velocity near the mortar’s muzzle. This information was correlated with the size and weight of shells and their respective lift charges

Jan 1, 2024

Coal strip mine operators in Western Canada often mine steeply-dipping multiple coal seams in mountainous terrain. The ability to fragment the rock waste layers above and below these seams with minimum disruption of the seams in large blasts normally involves decked charges in large rotary boreholes. Mining these seams may take two or more separate blasts to break the waste wedges above and below the coal, but these wedges can be blasted in a single shot for better mining efficiency.

Jan 1, 1985

By Lawrence Mirabelli, Wayne Lidkea, Mario Paventi

On Januarv 1, 1996, INCO Limited, Tamrock OY, Dyno Nobel and CANMET formed a consortium for the development of robotic mining equipment called the Mining Automation Program (MAP). This project was a tive- [5] year research and development program that combined the talents of the above organizations to facilitate the development of mining equipment and systems for tele-remote mining. The year 2000 brings MAP to conclusion with actual production process trial testing of the developed prototype equipment and systems during the period between May and October. MAP consisted of multiple projects all of which are based on the communication system developed by INCO Mines Research and currently sold and marketed by Automated Mining Systems Limited. The main projects include the development of a positioning and navigation module (including a software mapping system that will be inherent to each piece of equipment), robotic systems for underground development and stoping operations, as well as software systems to support the use of this equipment. Included in the program was the establishment of a Research Mine, at INCO’s 175 orebody, Copper Cliff, Ontario, Canada. This facility allowed for the on-site collaboration between the companies and research organization in the design and testing of techniques and equipment to mine with TeleminingTM. Some of the prototype equipment developed through the program are: a tele-operated drilling jumbo, a tele-operated load-haul-and-dump [LHD] tram, a tele-operated production drill, a remote initiation system for programming and detonation of electronic detonators, and the development of a vatiable energy bulk emulsion explosive system, including loading equipment, to deliver the explosives to boreholes. Use of tele-operated and automated equipment for mining mandates a dramatic change in the traditional drill/blast/muck/support cycles in the underground mining process.

Jan 1, 2001

By D Linn Coursen

Detonation propagates in the subject blasting agent at about 2.7 km/sec when it is heavily primed but explosion propagates in it at only about 0.43 km/sec when it is lightly primed. When propagating at 0.43 km/sec, it produces a borehole pressure that is slightly less than 1 kb, but no yellow fumes or other sign of incomplete reaction. It is a pumped AN/emulsion blend to which additional water is added by circumferential injection at the inlet of the hose through which it is pumped.

Jan 1, 1994

By L. L. Oriard

he Metropolitan Water District of Southern California (MWD) supplies water to some 16 million people in a semi-arid region. Most of this water is imported. Some of the supply lines cross over the San Andreas fault, one of the most notorious and active faults in the U.S. There was a serious need for emergency water in case normal supplies should be interrupted. To fill that need, MWD had to find a reservoir site on the west side of the San Andreas fault, west of the mountains. Because of the distinctive nature of the location, it was necessary to construct a huge “bath tub” by building a dam at each end of a valley, requiring some 115 million cubic yards (88 million cu.m) of fill. In effect, two large-scale surface mining operations have been under way simultaneously. The $2.2 billion project is known as the Eastside Reservoir Project. Because of space limitations, this paper will be limited to those topics which are expected to be of primary interest to explosives engineers, principally related to large-scale rock fill production. There is not sufficient space to discuss the many diverse geotechnical questions related to site selection, geological and geophysical field testing, laboratory testing and design considerations. This brief overview may assist those who might be interested in making a tour of the project site following the ISEE conference.

Jan 1, 2000

By Michael Wieland

The thrust of this report is to overcome some of the technical deficiency in the scientific methodology that correlates the work output during a charge explosion to the resulting toxic fumes. Thermodynamic work-principle models yield (undissipated) shock and heave results for shooting underwater and in rock stratum with related toxic fumes. Underwater circumstances yield reliable test data for the work process, though questionable or no fume results. Work-output measurements in rock shots remain difficult if not intractable, though some fume reports exist. Underground tests with thick-wall metal pipe bombs yield consistent toxic fumes trapped within the test chamber. The work output, rendered as fragment kinetic energy, can be inferred from the well-tested theory of R. W. Gurney, originally designed for military ordinance. Therefore a work-principle model for cylindrical pipe bombs was developed to predict fragmentation work output and reaction-zone fumes, permitting the double comparisons to reported and inferred results.

Jan 1, 2010

By J R. Hearst, T R. Butkovich

Explosive-induced fracturing and permeability enhancement far from a free face were studied. A one-dimensional computer program, SOC, was used to predict the total failure-associated distortional strain, ef. Laboratory and field experiments associated the calculated ef with the observed fracture and permeability enhancement. An ef value of 0.015 corresponded to the observed radius of effect, which was about seven times the cavity radius and was consistent with predictions from SOC and from the literature.

Jan 1, 1976

By R Frank Chiappeta, Eduardo Nixon, John Dean Smith, Tom Treleaven

"The creation of the Panama Canal was far more than a vast, unprecedented feat of engineering. It was a profoundly important historic event and a sweeping human drama not unlike that of war. Apart from wars, it represented the largest, most costly single effort ever before mounted anywhere on earth. It held the world's attention over a span of forty years. It affected the lives of tens of thousands of people at every level of society and of virtually every race and nationality. Great reputations were made and destroyed. For numbers of men and women it was the adventure of a lifetime.

Jan 1, 1998