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By Donald J. Moore

It has become more important today than ever before to reduce costs and improve equipment utilization. One area where such improvement can he achieved is in the use of explosives. Effective blast design for efficient use of explosives as well as optimum fragmentation can achieve this. Towards this end we must have available to us a practical design method in which experience and observation can be translated to engineering concepts. We must he able to communicate the design data to field blasting personnel as well as management in an understandable way.

Jan 1, 1975

By Steve Collinsworth, Nils Heinke

In 1989, I realized the definite need for change in the Blast Hole Drilling Industry. With over 25 years of experience in dealing with the industry, I am well inGormed and educated concerning the problems that occur in Blast Hole Drilling. After continues interaction with the Drill & Blast Superintendents, Drillers, Purchasing Agents, Mechanics, and others in the field, a basic understanding was developed as to the origins of the main problems that the industry f&s with their drillings programs.

Jan 1, 1997

By Koichi Kurokawa, Takeo Ueda, Masahi Nakano, Yoji Tasaki

A lightning strike generates several 10kA and several billion volts, and earth currents generated by lightning is dangerous to some underground and all surface blasting operations. In order to evaluate the safety against lightning in conventional electric firing method and electromagnetic induction blasting system, a test is conducted by connecting a wire with an impulse generator. Frequency of impulse current used in the test is 17kHz and the waveform is a vibration type and the duration time is 250 ~usec. The results of the test show that induced current increases with the increasing of impulse current. In the case of MBS connection, when maximum primary current is 1700A, Maximum secondary current is 11.8A and the electric detonator is fired at this condition.

Jan 1, 1988

By Nobel Insurance Service

[Executive Director’s note: ISEE is committed to continuing its efforts to ensure that blasters be made aware of the issue of migration of carbon monoxide resulting from blasting operations. In the July/August 2001 issue of the J o u rnal we printed excerpts from “Carbon Monoxide - The Silent Hazard,” an article from the Safety Update, published by Nobel Insurance Services. We also re minded readers of the text from the 17th edition of the ISEE Blasters Handbook in its section on trench blasting as follows: “...consideration must be given to the proper venting of gases generated from the blasting. Should those gases spread laterally rather than vent directly to the surface, the gases may travel underg round and finally vent well outside of the planned area. Such events may be caused by the strata, soil conditions or root systems, or existing and/or abandoned utilities or other man-made structures. In the worst situation, gases resulting from the detonation such as CO2, CO, and/or N Ox may travel through the strata and find their way into basements of nearby homes or businesses.” While incidents are rare, a number of cases in re c e n t years have resulted from outdoor blasting operations p roducing carbon monoxide gas that has migrated t h rough the earth and accumulated in nearby enclosed spaces. T h e re are steps that a blaster can take to be proactive in preventing incidents. These steps and studies of the occurrence have been expertly presented in several papers presented at ISEE conferences and included in the ISEE Conference Proceedings, available th rough the Blasters Library. In addition, Material Safety Data Sheets provided with explosives used in surf a c e blasting should provide additional information on gases p roduced by detonation. Below, we have reprinted the IME white paper, entitled “Fumes from Blasting Operations.” The paper underscores the unique set of circumstances that combine to contribute to high concentrations of CO measurements in underground, enclosed spaces following the detonation of explosive materials and provides recommendations to blasters

Jan 1, 2004

By Connie Postupack

The purpose of the workshop is to show the effect of various blasting factors on the overall results.

Jan 1, 1994

By Michael S. Wieland

This report focuses on the U.S. Bureau of Mines research regarding desensitization and malfunction of delay detonators and cap-sensitive explosives. Delay blasting in underground coal generates tremendous shock waves and rifting forces that fracture and heave coal. The shock waves from charge explosions radiate outward in all directions through the coal, impacting neighboring charges with later delays. The impact phenomena have debilitating effects, causing degrees of reduced charge performance ranging from misfires or weak detonations to out-of-sequence detonations. Impaired charges react poorly, fracture less coal, and produce fumes with higher toxicity. Coal-mine, underwater, and simulator tests were conducted to more thoroughly understand the shock damage mechanism. Recently the U.S. Bureau of Mines partially resolved the malfunction problem by demonstrating the feasibility of formulating a rugged explosive. This rugged cap-sensitive candidate passed the requisite tests for certifying an underground coal-mine explosive. With natural aging the formulation rapidly lost initiation sensitivity. The charge formulation had to be rebatched to finish the testing and therefore could not be certified.

Jan 1, 1992

By David R. Ziegler

The concept and facts concerning "threshold blast damage" are not considered "general knowledge". Perhaps because of a lack of knowledge, understanding, and experience of blasting effects, property owners and lay-persons may attribute a wide range of common cosmetic conditions to "blasting damage".

Jan 1, 1997

By Richard E. Danell

"There are a variety of approaches for wall control blasting in open pit mining operations. Safety forworking in the pit is the principal benefit. There are also a number of economic and productivitybenefits when appropriate techniques are used. The purpose and requirements of wall control blasting can vary quite significantly for different operations. When considering blast design, geology, geotechnical factors, drilling, explosives, economics and blasting history are all part of the engineering design process. In many operations, there is a high reliance on blasting history and economics for determining wall control blasting measures. This presentation outlines approaches that broaden the design process and discusses their advantages."

Jan 1, 1997

By William C. Burkle

In this paper, the author has cited essential areas in which the explosives engineer can assist the mine manager in his planning of an entirely new operation or in a major expansion of an existing facility.

Jan 1, 1990

Prediction of fragmentation in Taconite Mining is an important aid to blasting engineers. A simple theory relates the intensity of radial fracture per unit length to distance from the borehole, from which a power law for mass fraction passing versus size is derived. For the lower end of the size distribution, the equation agrees well with several published examples of fragmentation from sieving of full scale blasts. Large size fragments arise from interaction of fractures from neighboring holes and pre-existing joints. Analysis of two assumptions regarding radial fracture interaction shows that complex fragmentation distributions can arise from the simple mechanisms proposed. Measured fragmentation falls between the two extremes calculated.

Jan 1, 1996

By T Barnes, K D. Sexton, T J. Tope

For the past decade, the U.S. Department of Defense (DoD) has been under increasing pressure from state and federal regulatory authorities to develop management strategies for waste streams generated at its bases, installations, and ranges. Since passage of the Federal Facilities Compliance Act (FFCA) in 1992, concerns have focused in particular on military munitions and energetic waste streams.

Jan 1, 1997

By Tom Treleaven

The widening of the Panama Canal to approximately 130 feet (40 m) for its entire length began just a few years ago. The original expansion program was slated for completion in 18 to 20 years, but has recently been reduced for completion within the next four years. This means that a tremendous amount of blasting at simultaneous points along the canal, by both the Panama Canal Commission (PCC) and many subcontractors, is necessary to achieve the new completion deadline. The accelerated program also imposed many logistical concerns, since marine trafIic is always heavy and cannot be stopped for blasting. Because some of the large and heavy cargo vessels clear the bottom of the canal by only about 6 feet ( 2 m), the blasting cannot result in any large boulders into the center of the canal, for fear of grounding and damaging a vessel, not to mention the traffic delays and lost income of approximately 1 to 2 million dollars per day.

Jan 1, 1997

By Randall S. Marks

Bonneville Dam, completed in 1938, included the smallest and busiest lock on the Columbia and Snake River Navigation System. To expedite barge traffic through this restriction, a new larger lock was designed and contracted by the U.S. Army Corp of Engineers.

Jan 1, 1997

By R. Farnfield, W. Birch

Arguably, some of the most restrictive statutory blast vibration requirements attached to mineral extraction operations can be found in the United Kingdom. Such limitations are, as a rule for the UK, stipulated together with a required statistical confidence that has to be observed in the blast design process in order to ensure total planning compliance. A key element in this procedure is the effect imparted by vibration data scatter from previous blasts as this becomes reflected in the site’s operational standard error statistic and in turn directly influences the maximum instantaneous charge weights that can be justifiably employed. The greater the scatter, the lower the compliant charge weights become.

Jan 1, 2006

By Vincent Thorne

On January 2, 1992, the R. Zoppo Company of Stoughton, Massachusetts started drilling and blasting operations on U.S. Army Corps of Engineers Project Number: DACW33-91-B-0072 to widen and deepen the Portsmouth Harbor and Piscataqua River Navigation Channel.

Jan 1, 1993

By R R. Vendebeek

The continuing evolution of explosives has most recently introduced emulsion explosives and heavy ANFO's to the market place. An explosives engineer has a multiplicity of explosives to choose from: dynamites, slurries, water gels, emulsions, ANFO's, and mixtures of some of these products.

Jan 1, 1987

By D T. Froedge

With successive generations of the Iso-Seismic System, we are acquiring more and more information about the actual behavior of blast induced ground, and airborne vibration, as it propagates through the environment. Some of the original “truths” that have been long accepted may have to be \revised.

Jan 1, 1995

By Douglas Bartley, Jay Elkin

The state of Pennsylvania was at one time one of the leading coal producing states in the east. However, legislation and industry trends over the last 10 years have adversely affected the amount of bituminous coal mined in Pennsylvania and the whole eastern United States. The application for and approval of a new mining permit is a very costly and arduous task. When a new mining operation is established it is crucial that nothing within the operator’s control causes the operation to stop producing. This paper discusses the action taken by a small mine in Pennsylvania when their blast induced vibrations rose to levels that typically would have resulted in a total mine shut down by the regulatory body governing such operations.

Jan 1, 2003

By Rolf Schillinger

Blasting activities on the surface or underground necessarily involve the most sensitive aspect of environment remediation, human response or annoyance. Such effects are unavoidably characteristic of those activities. For this reason, blasting activities are governed by law and official regulations under surveillance of authorities, where companies and explosives engineers have to proceed within proper limits. Subject of the paper is a practical way of handling some necessary vibration standards being focused on blasting activities. The paper is based on the German Standard DIN 4150, Part 1 - 3, “Vibration in buildings”, Part 1: “Prediction of vibration parameters”, June 2001, Part 2: “Effects on persons in buildings”, June 1999 and Part 3: “Effects on structures”, February 1999.

Jan 1, 2006

By Tom Treleaven, Andrew Williams

Several contracts were let in Greenwich, Connecticut, for the installation of a sanitary sewer. The majority of the excavation was in rock and involved numerous challenges due to the following conditions:

Jan 1, 2003