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By Ron Woolf, Corry Goumans

This paper describes rock slope remediation performed along America’s first Superhighway, the Pennsylvania Turnpike and in particular, the specialized drilling equipment designed and built by Pacific Blasting to complete this work. This S-month project was performed on an existing rock cut slope within the Bedford Narrows, a gap formed by the Juniata River through Evitts Mountain. These rocks are in the folded Juniata and Tuscarora Formations within the Valley and Ridge Province and strike northeast with near vertical to slightly overturned bedding.

Jan 1, 2001

By Steve Dillingham

The origin of the written blasting log or shot report can likely be traced back to the earliest annals of blasting and record keeping. These records were, for the most part, a way of checking inventory, production progress, or billing, and not necessarily designed with the intention of being used as a legal document in a court of law. As our litigious society has evolved to include far reaching regulatory requirements, however, the blasting log has developed to support and aid in the defense of the common blaster from blasting lawsuits by providing a comprehensive written report of his or her actions.

Jan 1, 2002

By Alastair Torrance, Italo Onederra, Do Sun Kim, Kush Patel, Gary Cavanough

Reactivity of ammonium nitrate-based explosives is associated with the presence of sulphide in the ground reacting with explosive products and in some instances causing spontaneous reactions which can lead to detonation. This paper explains the mechanism of these reactions, the potential cause of spontaneous detonation and how inhibited explosives prevent the reaction

Jan 1, 2019

By Norm Disley, Kingsley Hortin, Gertjan Bekkers

As part of the expansion of the Kidd Creek Mine to 2,682 meters (8800 feet) below surface, two largediameter 3000kW (4000HP) booster fans were installed at the 6000 level. Shortly after commissioning the fans, significant damage to the fan bearings were observed, forcing several shutdowns for repairs, which were very disruptive to the mine’s production process.

Jan 1, 2008

By Tom Treleaven

This guide presents numerous patterns that provide 8 millisecond separations between initiated charges. The guide is tabulated in seven sections to provide quick reference by number of decks or bunch blasting. The pattern is presented in the section where the highest number of decks works. It should be noted that patterns applicable to multiple deck shootings are also applicable for fewer decks.

Jan 1, 1997

By Alastair Torrance

The performance of commercial explosives is clearly influenced by the conditions under which they are used. Mining companies are supplied with Technical Data Sheets which provide details about explosive properties and its suitable application. These are generally produced using laboratory techniques which may not accurately reflect the quality and performance of the product in the field.

Jan 1, 2013

By D. Lansburg

Electronic detonators are increasingly being used in today’s blasting in quarries, seismic, surface and underground mines. Electronic detonators offer several distinctive features over electric and non-el (shock tube) detonators including better timing accuracy resulting in excellent fragmentation and vibration control, field programmability and digital safety means. Because of the prerequisite electrical communications between the electronic detonators and the blasting machine, the layout or hook-up of these detonators can play an important role in obtaining the communication fidelity.

Jan 1, 2011

By B Mohanty

Currently there exist several explosive quantity-distance (Q-D) rules variously exercised by most countries to protect personnel and property against the effects of accidental explosions. These regulations apply to manufacture, transport and storage of explosive products. This paper reviews the technical basis behind these regulations, as they apply to commercial and military explosives. The characteristics of a blast wave and missiles issuing out of an explosion site and their role in determining the level of damage to a target are discussed. The need for further research on the effect of detonation of charges of non-standard geometry, and under confined conditions such as tunnels is discussed. The challenge in estimating the net quantity of explosives involved and calculation of its TNT-equivalency is also highlighted.

Jan 1, 2014

By Jason Baird, Philip Mulligan, Caleb Baumgart

This report details the pressure variances, measured at four pressure sensors placed equidistant from the center of an airburst explosion, as the blast pressure from a single charge expands radially. Many of the empirically derived equations used for predicting the blast pressures of an explosion, assume a point source detonation and that the radial pressure expansion is equal. The authors understand that the equations used to approximate the blast pressure may not have 100 percent agreement with the observed pressure. However, during previous research at Missouri University of Science and Technology (Missouri S&T) the pressure variances had a range of 1,200 psi, between the four pressure sensors placed two feet from the center of a 1/2-pound (226.8 gram) of hand packed C4. The variances indicated that at the close distance from a suspended explosive charge the pressure does not behave as that observed from a point source.

Jan 1, 2014

By Michael S. Wieland

"This report investigates whether it is tractable and thereupon reasonable to remove the boosterinfluences when ranking the toxic fumes of non-cap-sensitive mining explosives. The hazard potential is represented by relative fume toxicity RFT, the resultant influence computed from a formulated rule with a restricted set (tally) of fume components and multiplying constants. The RFT result is compared to the rule criterion that represents the worst case tolerable toxicity stipulated by regulations or otherwise. The typical nonstoichiometric booster composition can render notable unwanted influence on the RFT ranking results. Historically, the remedy was to shoot the booster separately and reduce the trial concentrations by the relevant subtractions. Unreal negative concentration results were noted on rare occasions, revealing the faulty nature of the reduction procedure. With thermodynamic reaction chemistry codes TDRC, on the other hand, the booster ingredients can be retained in or removed from the reactant tabulation, yielding reduction factors taken as the concentration ratios for the two circumstances. The underlying presumption regarding reduction factors is that the ratios of component concentrations with and without the booster ingredients when resolved theoretically ought to equal those rendered experimentally, when tractable. Upon rearranging the presumed relationship, the unadjusted fume concentrations divided by theoretical reduction factors yield the wanted readjusted fume concentrations, thereby removing the booster influence without generating unreal negative concentrations."

Jan 1, 1999

By Eduardo Lozano, Vilem Petr

The use of explosives bring countless benefits to our everyday lives in areas such as mining, oil and gas exploration, demolition or avalanche control. However, because of the potential destructive power of explosives, strict safety procedures must be an integral part of any explosives operation. The goal of this paper is to provide a solution against the hazards which unfortunately accompany the use of explosives. For this reason, a blast shield is specifically designed and tested for protecting personnel against these unpredictable effects. This document will develop a complete analysis answering the following questions: what are the potential hazards from an air blast; what are their effects; and how can we be protected against them. In order to answer these questions, theoretical, analytical, and numerical calculations are performed. Finally, a full blast shield prototype is tested under blasting conditions proving its effectiveness as a safety device while explosives are used.

Jan 1, 2015

By Robert Hopler

Testing Stations Abroad At the Seventh International Congress of Applied Chemistry, Drs. Mente and Will communicated a paper on the above subject. All large coal-getting countries employ testing stations of some kind, in order to safeguard, to the highest possible extent, the lives of the men employed in this industry. Most countries employ galleries of considerable diameter, and fairly short length; but within recent times, long galleries, with drives and other accessories approaching as closely as possible the actual conditions of mining have been installed. The following are the details of the testing stations employed in the countries mentioned.

Jan 1, 2010

By Joshua Hoffman, Braden Lusk, Kyle Perry

Shock tubes are used to simulate large-scale arena explosions without the use of full-scale arena sites that utilize large quantities of explosives. Instead, small explosive charges can be used to drive shock tubes. When this is done, the geometries of the explosive charges can alter the resulting pressure time curve. A common geometry chosen for the explosive charge is a sphere in order to be congruent with the spherical shockwave that emanates symmetrically in three dimensions from the detonation point. This paper reports on the findings from experiments that study the effects of altering the charge geometries and explosive types while keeping the TNT equivalency constant. Peak pressures and durations were affected by these changes. Directional phenomena are exaggerated by the use of certain charge shapes and detonation points. The speed of the detonation front in the explosive being greater than the speed of the shockwave in air played a critical role in the resulting pressure time waveforms. Waveform manipulation can be used to generate job specific waveforms that ultimately benefit the shock tube operators and their clients.

Jan 1, 2010

By Robert Hopler

RBH Note: The Illinois Powder Manufacturing Company was established in 1907 and was acquired in 1957 by American Cyanamid. The latter company left the explosives business in 1969.

Jan 1, 2010

By Brian Warner, Siavash Mahvelati, Douglas Rudenko, Mohamad Sharif

Predicting and optimizing production shot vibrations using time-shifting and superposition of signature hole waveforms (seed waves) has been widely used for many years. In this method, a single borehole is detonated and recorded with seismographs at the locations of concern. Since a single hole waveform is a reproducible event, it is reasonable that the seismic signature from a multi-hole production shot can be predicted by summing a series of single hole waveforms that have been time‐lagged at intervals corresponding to delay times from the production shot. However, there are instances where seed waveforms are collected at locations other than the exact location of concern, which raises questions regarding the applicability of such recordings. The present study adopts the well-known concept of dispersion of surface waves to predict seed waves at a location of interest based on seismograms recorded at a closer offset. Surface waves, as their name suggests, are seismic waves that propagate along the Earth's surface. They are the dominant wave type within one wavelength from the ground surface. Surface waves are dispersive in nature meaning that in a layered medium, wave components with different frequencies travel at different velocities causing an input signal to disperse as it propagates. The proposed technique takes seed waves recorded at one location as the input and passes it through a frequency-dependent function developed using site dispersion characteristics. The site’s dispersion characteristics are either measured directly with surface wave methods or retrieved using shear wave velocity information. The output of the function is the seed wave prediction at the farther location of concern. The theoretical background, including the underlying assumptions and limitations, is discussed in detail, and the application of the technique is illustrated through field data from two sites.

Jan 26, 2026

By Dick Green

During the recent troubles in Northern Ireland due to terrorist activities, there have been many buildings demolished or damaged by improvised explosives. This article explains about the Demolition of Churchill House in Belfast, the first controlled use explosives to demolish a high rise office building since the recent troubles started, and a further indication that normality is returning to the lovely city in Ireland.

Jan 1, 2006

By Chick Kerkering, Stephen Iverson

Perimeter control blasting is common in civil construction projects but not as common in mining. A poorly designed and executed underground mine development blast design can result in unwanted wall rock damage. This damage increases the risk of rock falls and injury. With the availability of good drilling equipment, it is a simple matter to add the few extra holes needed to change conventional drifting into drifting with perimeter control.

Jan 1, 2008

By Jorge Flores, Benjamin Cebrian

Blast Optimization at a high altitude mine operation involves not only the selection of the right drilling designs and explosives but also the circumstances of operators working at low oxygen levels and low temperatures.

Jan 1, 2015

By Laurence Neufville

Proper risk assessment and blast design are very desirable to the execution of a blast. Not only will this ensure that it achieves its desired outcome, but the probability of complaints and litigation will be reduced. Blasting engineers rely heavily on site-specific data for analysis and input to the blast design equations, and therefore data collection is critical to this process. The traditional approach to data collection is to carry out site-specific reconnaissance by visiting the site, but the time spent doing so can be reduced if a remote sensing approached is adopted.

Jan 1, 2009

By Clay McNail, Paul N. Worsey, John Schillie

"This paper is the result of undergraduate student research over the period of 2 semesters at UMR, which was focussed on developing a practical way to pneumatically stem horizontal boreholes, mostcommonly used underground. The majority of dry horizontal underground boreholes are pneumatically loaded with bulk ANFO. ANFO is preferred due to its low cost and the ease of pneumatic loading. However, stemming underground in the United States is a rare practice. In sharp contrast, stemming material (crushed stone or drill cuttings) is virtually always used in surface holes. The purpose of stemming is to increase blast efficiency by containing the explosive energy in the ground and to reduce environmental effects such as air-blast. The problem with stemming horizontal boreholes are; gravity cannot be used to load stemming material and the ANFO does not have a good interface due to problems with withdrawing the hose and the loading itself. This work follows on from Wilkins’ work on stemming angled boreholes."

Jan 1, 1999