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By Sandra Penttinen

There are several ways to get a positive reaction from neighbors to blasting projects. When you need to enter structures to conduct a pre-blast inspection, the impression you make on the structure owner must be positive from the very start. Public relations with neighbors is the key. The purpose of all communications with persons residing near planned blasting operations is to educate structure owners as to what will take place during the blasting operations, to explain that safe blasting practices will be followed and vibration and airblast limits will be imposed to protect surrounding structures from damage. Once access into the structure is obtained, the structure owner can be shown, by careful documentation, all existing cracks and defects in the structure prior to blasting and construction. The objective of your visit and all communications is get your foot into the door and win the confidence of the structure owner so that he or she understands blasting will not compromise the structure.

Jan 1, 2006

By C. Braun, C. Kennedy, P. Katsabanis

A series of small scale tests, simulating multi-hole blasts have been performed to establish the effect of delays on blast fragmentation. The blasts were performed in high quality granodiorite blocks, which were cut from stone prepared by dimensional stone quarry operations. The pattern used was equilateral triangular, with a distance of 10.2cm between boreholes, which had a diameter of 11mm, were loaded with detonating cord and the coupling medium was water. The delays used were achieved using different lengths of detonating cord for the cases of delays between 0 and 100 microseconds between holes and a sequential blasting machine firing seismic detonators for larger delays up to 4ms. All fragments were collected and screened. The experiments showed that the coarsest fragmentation was achieved with simultaneous initiation of all charges. Fragmentation became finer with delay time between holes up to 1ms between holes. The results show that in moderate to competent rock, similar to the granodiorite of the experiments, fragmentation optimization requires delays of few milliseconds per meter of burden. In view of the findings, which agree with previous published work, the current trend of selecting fast firing times for fragmentation optimization is questioned.

Jan 1, 2006

By J M. Laboz Bernard

Among the numerous technical evolutions in the blasting environment we are going to describe below the concep

Jan 1, 1995

By Jack Eloranta

To improve control of blasting, tests were performed to assess non-electric cap accuracy. Simultaneous testing using a Velocity of Detonation Recorder (VODR), Red Lake Lo-Cam and an Instantel DS-677 blast monitor was done. Favorable comparisons were found in the three records . This testing confirmed the accuracy of an inexpensive and expedient cap testing procedure.

Jan 1, 1992

By Mark Abernathy

When most people think of a motor vehicle accident, the direct costs resulting from that accident, such as vehicle repair or towing charges, are generally easy to quantify. However, the indirect costs associated with an accident are often overlooked. These indirect costs can take a tremendous toll on a company in more ways than you might think.

Jan 1, 2006

By Wilfrid Comeau

The RICHTER scale is used in classifying earthquake severity. It is an energy scale giving the estimated energy liberated at the source of the earthquake. Earthquake damage on the earth’s surface, for example at the epicenter - spot on the earth’s surface directly above the earthquake, for a given RICHTER number can vary. This depends on the depth of the earthquake focus. Deeper earthquakes will generally cause a lower level of damage at the epicenter but the damage will be spread over a greater area. As mentioned by Randy Wheeler on Blastserve, each successive RICHTER number represents about a 30-fold increase in energy. This scale is open at both ends with “0” RICHTER equal to about 104 Joules. The lowest level detected by sensitive instruments is about 2 on the RICHTER scale or about 107 Joules. The highest-level earthquake detected at 8.9 RICHTER represents a release of about 3 x 101 7 Joules.

Jan 1, 2003

By Rob Farnfield, Yuill Gavin

The rock blasting industry continues to be under pressure to reduce the level of vibration induced by the use of explosives. In recent years much research and development has been directed to minimizing vibration levels by controlling the delay period between blast holes. The most commonly applied technique is known as Linear Superposition. This technique takes the vibration produced from a single-hole test shot and simulates the vibration that would be produced from a full-scale production blast. The simulation can be run with various delay periods and the optimum delay chosen. The success of the Linear Superposition technique depends to a great extent on having accurate delay detonators and on the single-hole test shot reliably indicating the vibration signal produced from each hole in a production blast. A quarry-based case study is given illustrating how these assumptions are not always valid. In this case the use of electronic detonators has controlled frequency but not vibration level. The paper goes on to describe a series of single-hole test shots in an U.K. limestone quarry. The vibration 2 signals recorded are examined in terms of variations in free-face provision, blast geometry, explosive properties, etc.

Jan 1, 2001

By Jeff Hammer, John McGregor

"The Twin Tunnels, originally constructed in 1964, have become a major choking point for trafficheading up to and returning from the Colorado high country along the I-70 corridor. To increase traffic flow, the Colorado Department of Transportation undertook the first widening of the East Bound Tunnel in 2013. After the successful completion of that project, CDOT began the widening of the West Bound Tunnel in 2014. Both projects had a limited schedule for tunnel construction of just nine months. The innovative blasting and demolition of the existing tunnel lining was a crucial component to the success of both projects. During the construction of the West Bound project in 2014 a large amount of surface bench blasting using conventional methods ran concurrently to the West Bound tunnel excavation to allow for enough room for the new tunnel portals."

Jan 1, 2016

By Carl Hendricks, Malcolm Scoble

There currently exists no viable means of obtaining continuous feedback on blast efficiency. This paper describes the adaptation of a loading shovel to serve as a diagnostic tool to evaluate the success of ground preparation. Work undertaken in a large western Canadian open pit involved microprocessor-based instrumentation for the performance monitoring of an electric mining shovel. The monitored shovel responses proved to be reliable indicators of variations in muckpile diggability. This approach is considered to provide a very comprehensive survey of post blast conditions since such a shovel interacts which every cubic yard of a blast.

Jan 1, 1990

By Jerry Wallace

Construction of a new grammar school required blasting within three meters of the existing school. Due to changes not anticipated at time of bid opening, blasting had to take place while approximately 200 children were in attendance inside the building. Blasting with children in such close proximity forced the blaster to review and revise a systematic approach to construction blasting and make changes to previous Rules of Thumb guidelines. The revised rules of thumb place Blaster-in-Charge at the top of the List. Other changes specific to the project included putting in place a blasting safety plan that included communicating the serious job hazards to teachers and students. The plan included stringent lockdown guidelines establishing school procedures for accounting for each student prior to the countdown-to-blast being implemented. Emergency communications channels were kept open so that any scheduled blast could be aborted at the last instance.

Jan 1, 2001

By Victor C. Bryan

"One of the more challenging issues facing operators of U.S. mines and quarries is blasting in an environmentally acceptable way. It is quite important that industry management understand and apply guidance, discipline, and control in the exercise of blasting operations. This presentation is a discussion of problems related to that environment away from the blasthole that may or may not be adversely affected by blasting and the steps management may consider in resolving resultant problems. In any case, one of the main concerns that will continuously be brought up is thatmanagement procedures inherent to good blasting is a uxporate responsibility of the mine or quarry business entity; and can not be delegated to the explosive manufacturer or supplier. This management attitude, based on education, training, and the comprehension that the process of production begins with drilling and blasting and consumes a significant amount of overall production costs."

Jan 1, 1995

By Don Bachman, Larry Heywood

Artificial release of snow avalanches, through the use of explosives, is a necessary component of safety planning and operations for ski areas throughout the Western United States, as well as in other alpine regions of the world. Climatic, meteorological and terrain factors leading to the development of avalanche conditions, in addition to release mechanisms and magnitude of the avalanche problem to ski areas will be discussed.

Jan 1, 1999

By Syed M. Tariq, Paul N. Worsey

Presplitting is a now a universally accepted perimeter control technique in rock excavation. The success of presplitting and the smoothness and integrity of the resulting perimeter is largely dependent on the nature of joints in any given formation. Many facets of jointing have been previously investigated. The results of the effects of joints frequency and spatial positioning were presented by the authors at the ISEE annual meeting last year. This paper includes the results of further research into the mechanism of presplit blasting being carried out at the Rock Mechanics and Explosives Research Center of the University of Missouri- Rolla.

Jan 1, 1996

By Steve Dillingham

There are some blasters and blasting companies that just seem to have better safety reputations than others. This is in spite of the fact that they are essentially doing the same type of work under similar conditions. To achieve that enviable safety reputation, it simply comes down to a strong safety culture prompted by a responsibility for others, as well as yourself and your company.

Jan 1, 2003

By Rachel Bernau

Water wells, aquifers, and pipelines rarely incur damage from nearby blast vibrations. Extensive ground vibrations may cause a drop in the water table thereby changing an aquifer’s structure or drying up a well. Studies on the reactions of aquifers and water wells have been performed in Montana, North Dakota, and the Appalachia Coal Region. All of these studies reported that vibrations did not change the properties of the monitored aquifers and water wells. Rather, evidence suggests that any incurred damage was caused by block motion and downsloping.

Jan 1, 2001

By Robert B. Hopler

First, a definition: “an explosive is called a permissible explosive when it is similar in all respects to the sample that passed certain tests by the national Bureau of Mines, and when it is used in accordance with the conditions prescribed by that bureau. * This was the definition as stated in Miners’ Circular No. 2,” published by the United States Bureau of Mines in 1911, and it is still applicable today. Of course there have been changes over the years, with the name “MSHA Permitted Explosive” now the legal terminology since January 1989, but the old 1911 circular still tells us what the material is. Note that the definition doesn’t even specifically state “coal mining.” A permissible can be required in guy underground operation that is deemed to have a gas or dust hazard, although in 1911 it was certainly meant to refer only to coal.

Jan 1, 1995

By J E. (Boet) Coetzee

SAFEX International, as the name suggests, is a global organisation, which has the fundamental objective of improving the safety of operations concerned with the manufacture, storage, transport, and use of commercial and military explosives and pyrotechnic products throughout the world. It is a nonprofit making organisation of manufacturers of explosives from all parts of the world, founded in 1954 with the aim of exchanging experiences within the explosives industry. Every third year SAFEX organises a Congress during which members present papers on selected themes and discuss reports of significant incidents that occurred since the previous Congress. Admission is for SAFEX members only, thereby creating a safe environment for discussing problems “within the family”. The XV Congress will celebrate the Association’s 50th anniversary in Geneva where it was founded. An overview of the Congress indicates its structure and covers aspects such as the training event, technical seminars and the themes for the plenary sessions and associated workshops. The paper also highlights the special event for the chief executives of member companies and the review of incidents that occurred in the industry since the last Congress. The Congress concludes with a social programme for delegates and their partners on the last day.

Jan 1, 2005

By Gordon M. Matheson, David K. Miller

Possible impacts to the water quality and production capacity of ground water supply wells by blasting is a common cause of complaints for blasting contractors, mining companies, and local regulatory authorities. The major complaints of changes in well water quality include; turbidity, discolored water (red, brown, black, yellow and milky water), and nitrate and/or coliform contamination. The major complaints for changes in well water production capacity include: loss of quantity production, air in water and/or water lines, damage to pump, and damage to well screen or borehole.

Jan 1, 1997

By A Brodbeck, AT Spathis

Australian regulatory control of ground vibration and airblast arising from mining, quarrying and civil construction operations is spread across a number of federal, state and local authorities and across a number of departments with various jurisdictions. The Australian Standard AS 2187.2 contains an informative appendix on damage-related criteria and it is the primary reference for the regulators. The complete standard and the informative appendix is currently undergoing major revision with a focus for the latter on implementing frequency-dependent criteria for ground vibration. Certain directions for change have been raised for consideration by the standing committee, ranging from fundamental issues of measurement and interpretation and others that overlap human comfort criteria. It is anticipated that some of the suggestions will eventually make their way into future standards after an adequate period of consultation and consideration by both the Australian public and others involved in the associated industries.

Jan 1, 2005

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