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By Steve Dillingham

In recent years, there has been a trend toward increasingly demanding blasting standards being enacted by local and regional regulatory authorities. The objective of this paper is to alert blasters of the difficulties that are created for blasting projects as a result of these restrictions, as well as the steps that can be taken to minimize future conflicts.

Jan 1, 1995

By Calvin J. Konya

For proper blast design, one must make the assumption that all blastholes release nearly ideal energy. In many types of blasting operations, blastholes release very little useful energy. These blastholes are called malfunctioning blastholes. Recent studies indicate that as many as 30 percent of all blastholes are malfunctioning. These malfunctioning blastholes are not an unusual occurrence.

Jan 1, 1988

By H. Frank Murati, D. S. "Sax" Saxena

The presence of a mobile home park with drinking water wells created a unique geoenvironmental deterrent to the developer’s plans for effective rock blasting, excavation, and development of water management areas (lakes) in connection with the construction of Crown Colony Resort, a residential cum golf course community in southwest Fort Myers, Lee County, Florida, USA.

Jan 1, 2002

By Lon D. Santis

This paper presents data and theorem to calculate the risk of experiencing undesirable lightning related events while blasting or while engaged in other lightning sensitive activities. The paper provides an overview of lightning hazards in blasting operations and a brief history of lightning related blasting accidents. Lightning continues to be the primary cause of premature initiations of explosives in mining; on average, over two such incidents are reported to the Mine Safety and Health Administration (MSHA) each year. The energy contained in lightning discharges and how this energy sets off explosives in mining is presented. Three categories of lightning warning methods: public media, lightning detectors, and atmospheric electrostatic field measurement are discussed. The remainder of the paper presents recently acquired data on the spatial characteristics of lightning development. This data is used to estimate the risk assumed by blasters under certain conditions. Risk estimations are made for electric and nonelectric blasting if persons are evacuated when cloud-to-ground (c-g) lightning approaches within a certain distance. For example, about 0.6% of all c-g lightning strikes have no other c-g lightning strikes within 25 miles in the previous 30 minutes. The paper shows that a typical blaster using nonelectric initiation in a high lightning density area with a 100% accurate lightning detector set to alarm at 25 miles would have a lightning caused unplanned detonation every 14,000 years.

Jan 1, 1998

By Ryan Redyke, Jared Redyke

The demolition of an old power plant boiler house in Parsons, Kansas calls for the use of some linear shaped charges. The steel is thick and the structure is heavy but gravity can be a blaster’s best friend. This entry did not win in a very competitive category. We thought it was worthy of coverage in the Journal of Explosives Engineering.

Jan 1, 2015

By C H. Ryu

This paper presents a simplified two-dimensional numerical model of block fragmentation in a Jointed rock mass during the late or throw stage of a blast after wave effects have subsided. The model is based on the distinct element method. Examples illustrate the approach and allow for a comparison of effects of Joint patterns on fragmentation and resulting block motion.

Jan 1, 1986

By John W. Brown

For seventeen years, I have been involved in surface coal mining in the Mldwest coal fields only to find that once again, I have experienced a problem that was not known to exist in our area. The existence of high sulfur coal seams and pyrite-bearing formations coming In contact with ANFO mixtures has presented yet another potential problem facing the blaster.

Jan 1, 1992

By Ettore Contestabile, Cameron Thomas

Implosive-type electrical/mechanical connectors such as XECONEX have been used extensively for joining electrical transmission lines. This implosive action of explosives has also been applied to other forms of high energy metal working with excellent results. However, as with many other products, the inherent blast energy of these units has caused some environmental concerns especially when used in proximity to inhabited areas.

Jan 1, 1995

By Ettore Contestabile, Cameron Thomas

Implosive-type electrical/mechanical connectors such as XECONEX have been used extensively for joining electrical transmission lines. This implosive action of explosives has also been applied to other forms of high energy metal working with excellent results. However, as with many other products, the inherent blast energy of these units has caused some environmental concerns especially when used in proximity to inhabited areas.

Jan 1, 1995

By Lina Lopez, Jose Sanchidrian, Manuel Lopez, Pablo Segarra

Previous work in which rock properties and blasting parameters (geometry, charging and timing) were reported together with truck filling times, is taken as a starting point for a thorough analysis of the influence of the former on the mucking velocity. The experimental set was composed by 11 blasts made in an open pit mine. Non-parametric, distribution-free statistics is applied. The mucking rates (in bank cubic meters per unit of bucket volume and per hour) appear to be clearly dependent on the explosive energy and powder factor, both magnitudes combined as energetic powder factor (energy per unit of rock volume). The mucking rate is a non-monotonic function of such factor in the range of the blasts analyzed. The determination of the function is optimum when the fraction of the explosive below grade is not considered and when the explosive energy is qualified as that delivered at a partial detonation regime. Different types of loaders seem appropriate for different energy levels. At low levels both front loaders and rope shovels obtain small productivities without a statistically significant difference in their performance. At high energy levels, front loaders qualify higher than rope shovels. Mucking velocities can be equally small at low energy powder factors and at high ones if rope shovels are involved.

Jan 1, 2008

By B Mohanty

Several parameters such as, Energy, Strength, Brisance, Impulse, and Bubble Energy, are in common use in the explosives industry today to rate commercial explosives in terms of blasting performance. However, this multiplicity of terms, their frequent interchange and their purported one-to-one correlation with expected performance have given rise to a considerable amount of confusion, and have often resulted in unrealistic rating of explosives. In this paper, various theoretical and experimental methods of estimating energy and performance of explosives are discussed and their relative merits examined. These methods include, Computer Code Calculations, Cylinder Test, Trauzl Test, Ballistic Mortar Test, Underwater Test and Model-scale blasting. It is shown, in the light of actual blasting process, that such measures cannot be considered accurate indicators of expected blasting performance as the properties of rock to be blasted are either totally ignored or only partially accounted for in these methods. It is also shown that no single technique alone among those currently employed by the explosives industry can lead to realistic rating of explosives in terms of expected blast results. The need for the adoption of a two-tier rating system, one based on chemical potential "energy", and the other based on blasting "performance" is proposed, and specific approaches to achieve this objective are outlined.

Jan 1, 1981

By R. Wharton, M. Bagley

The paper reviews the likely introduction of a European directive covering the sale of pyrotechnic articles in member states of the European Union. The background and structure of the directive are described, together with the range of products covered (which includes fireworks, theatrical pyrotechnics, vehicle airbags and seat belt pretensioners, and certain cartridges). Possible timescales and the implications for industry are also discussed.

Jan 1, 2007

By Chen Aiping, Wei Banyun, Chen Canchang

"The gaseous explosives consisting of combustible gas and combustion-supporting gas wereused in the opening end of a steel pipe and the ignition was in the closed end of the pipeusing continuous air feed within the permissible length limit of industrial equipment, theexperimental results show the mechanisms of forced transition from combustion todetonation and what is the effective equipment for the transition."

Jan 1, 1993

By Unknown

Contact Local Law Enforcement Authorities. Contacting the local law enforcement authorities is essential to the quick recovery of explosives taken in a crime. Contact Local ATF Office. The local ATF office will work with the local law enforcement authorities investigating the theft. They can also assist in the preparation of the Theft/Loss Report for submission to the U.S. Bomb Data Center.

Jan 1, 2009

By Mauro Fornaro, Marilena Cardu, Renato Mancini

Detonating cord cutting is widespread in dimension stone extraction, especially in the case of hard, abrasive stones as granites, an important resource for Italian industry. General data on this production sector are briefly discussed and analyzed in the first part of the paper. The theoretical basis of operation are summarized, and compared to data obtained from selected commercial cases, in the second part.

Jan 1, 1994

By Qingshou Chen, Paul N. Worsey

It has been recently argued that rock strength has little effect on the final results of pre-split blasting and is of only minor importance when blasting rock in general. However, it can be shown that the maximum borehole separation for optimal perimeter blasting results with constant borehole and loading configuration is strongly dependent on the tensile strength of the rock.

Jan 1, 1986

By David Harrison, Brian Harrison

The Army Corps of Engineers completed the Charleroi Lock and Dam in 1932. It is located on the Monongahela river approximately 22 miles (35k) south of Pittsburgh in Charleroi, Pennsylvania. It is comprised of a 420-foot (128m) gated dam, and a 720-foot (219m) by 56-foot (17m) land side lock, which provides for a 16.6 foot (5m) vertical lift.

Jan 1, 2018

By Greg Wyartt

Although electronic detonators and blast initiation systems have been commercially available for several decades, uptake in the Australian mining industry has been very slow when compared to other global mining regions. The safety and operational advantages of electronic initiation are generally well understood in Australia, however there has been a prevailing perception that these advantages do not outweigh the extra financial and technical investments.

Jan 1, 2019

By F M. Dantini, P Berry

An experimental investigation on the trend of cratering induced by explosives placed on rock masses was carried out. By using various types of explosives and rocks having different geomechanical parameters, it was possible to evaluate the influence of the explosive-rock coupling. Furthermore, the importance of the parameters defining the rock and the explosive for the absorption of energy induced in the rock mass, is pointed out.

Jan 1, 1981

By R M. Bhatawdekar, A I. Theresraj, H S. Venkatesh

Wadi Limestone Quarry is one of the largest captive mines of Associated Cement Companies Ltd, India. The mine management wanted to extend the excavation as close to the plant as possible for maximum exploitation of the deposit. The National Institute of Rock Mechanics and the management of Wadi Limestone Quarry carried out comprehensive investigations to evolve a methodology to control vibration and flyrock within safe limits.

Jan 1, 1999