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By R. F. Favreau, Patrice Favreau

In many quarries and construction sites visited by the authors over the last 50 years, the latter have observed muck piles from blasting with explosives, which included numerous large blocks, in some cases of dimensions larger than the input to the crusher. The names of these sites cannot be given in the article because the owners insist that data obtained on such visits be kept confidential. Often the blasters felt that the natural fissures in the rock would compensate for the use of a low powder factor, and they asked the authors to explain why such blocks were present. A detailed analysis of the situation often indicated that the cause of the blocks is that explained by figures such as 6 and 7 below in the article.

Jan 1, 2018

By Paul Worsey, Barbara Robertson

In June 2007, Missouri Science & Technology (formally UMR) successfully held its 5th and 6th Explosives Summer Camps. The camps, which include substantial industry participation, have been an outstanding success with both the students and their parents. They have also spawned a large amount of local, state and national media attention, including NPR and an article in the New York Times on the 3rd of July 2007.

Jan 1, 2008

By Roger Favreau, Patrice Favreau

The article reviews the aspects which contribute to the quality of the results from a blast with explosives, namely a good floor, no large blocks, easy mucking, and explains the mechanisms of the blasting process which decide on the quality of these aspects for a given blast method, and how these mechanisms can be simulated from basic principles. It proposes that good fragmentation size distribution can also be important if the rock is going to a crusher, e. g. for the ore in a mine and for the rock excavated in a quarry.

Jan 1, 2012

By R D. Skaggs

A good blast is dependent on a well engineered design. However, a good design's performance depends on the control of the drilling and loading of the blast holes. The key stone to good blasting is the drilling of straight holes of the correct orientation in the required positions.

Jan 1, 1991

By O. Cermak, F. Degonld

Although 3D fragmentation analysis is a relatively new technology, it is rapidly gaining popularity among mid-sized mining operations and quarries. The results provided by this technology are adequate, but like other picture analytic methods, it mainly focuses on the surface of the muck-pile. These results are incomplete or incorrect as falling rocks and boulders from the stemming zone are constantly influencing the muck-pile surface. This obstacle can be overcome by collecting a large amount of data and analyzing it over time. However, this is not always an ideal solution, as companies prefer to receive results immediately after the blast to make resource allocation decisions, production planning, and plan for the next blast. Over the past year and a half, we have conducted a study on various muck-pile fragmentation analysis results from 3D modeling in Central Europe, comparing the results between the surface and inside of the muck-pile. By analyzing multiple shot results, we were able to determine the percentage difference between the top and inside fragment sizes and calculate the range of correction coefficients for different rock types. Applying these coefficients to a single muck-pile surface fragmentation analysis allows us to determine the actual fragment sizes inside the muck-pile. This enables us to make informed decisions regarding loading, hauling, material mixing, and proper crushing or milling. By overcoming the limitation of surface-based analysis, we can now accurately evaluate blast performance, which leads to better processes optimization and increase efficiency. As 3D fragmentation analysis becomes more widespread, we expect to see even more benefits for the mining and quarrying industry

Jan 1, 2024

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 Philemon Desrochers, Ken Qian Liu

Following the success of the West Ore Zone distress mass blast in 2001 at Brunswick Mine, a similar approach was taken to distress the North Regional Pillar (NRP) which contained over 3 million tonnes of high grade ore. The NRP is located on the 1000 m Level with very poor hanging-wall (H/W) rock mass qualities. After an extensive geotechnical review, the distress slot is located close to the foot-wall (F/W) of the NRP in order to have the competent ore as H/W. The longitudinal area to distress covers 115 m along the strike and 85 m high from 1000 1-sub to 850 Sill. Prior to the final mass blast, 3 voids were created to allow rock swelling: the North void, the South void and the trench just below the mass blast. After over one year of preparation, the mass blast of 202,000 tonnes was successfully initiated on February 7, 2003 with 1561 electronic detonators and 210,000 kg of emulsion explosives. The blast achieved its objective of distressing the NRP as indicated the mine-wide micro-seismic monitoring system. This paper describes different stages of the project from void preparation to the mass blast itself, as well as some detailed aspects such as muck-pile prediction for mucking sequence with the help of DMC_Blast simulation code and electronic detonators.

Jan 1, 2004

By Goran Lande, Bernt Larsson, Dennis Clark

The effects of vibrations on close surroundings has been studied in Europe and the United States extensively in the past three to four years due to the ever increasing demands of environmental control. Therefore, "routine measurements" or "standard vibration consulting services" are being carried out by numerous firms with widely different qualifications.

Jan 1, 1983

By Steve Dillingham

Change occurs all of the time. In fact, it’s fair to say that change is a constant. Sometimes the change is inconsequential, but sometimes the change impacts us d i rectly and severely. Take regulations, for instance. Complying with regulatory requirements is just part of the job for those involved with explosives. But in recent years, it seems as if new or revised regulations in areas such as hazardous materials training, drug and alcohol testing, security issues, or local licensing/permitting standards are changing the way we operate on a recurring basis. Simply keeping track of all of these regulations has become a full-time job.

Jan 1, 2003

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 Larry Schneider

In recent years, many individuals looking into the future of the blasting industry have predicted that the most likely next technological breakthrough would be the use of high precision, digitally controlled detonators. This seemed logical since not only was there much room for improvement in this area, but any significant improvement in delay timing could yield great benefits in productivity and control of adverse effects. And in fact, within the past two or three years, such electronic detonators have been introduced in the field by a number of different manufacturers. These systems are currently being used in many routine blasting operations around the world which are being closely watched and evaluated.

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 Stephen Chung, John Carpenter, Scott Gosch, James Breedlove

While controlling fly rock and ground vibration in quarrying in the neighborhood of a residential area, producing good fragmentation and keeping different grades of material separated in a muckpile are important in maintaining the productivity of quality aggregates. This paper describes a single row production blast for the study of fragmentation and displacement in the grade control carried out at a quarry of Barrett Paving Materials Inc. in Sylvania, Ohio. Digital video imaging was used to monitor the blast-induced motion of the bench face as input to the DMC_Blast (Distinct Motion Code), for the analysis of the formation of the muckpile. The actual digitized blast video and the DMC_Blast simulation are compared. The displacement and mixing of all the inter-bedded limestone layers are made visible in the simulated cross-section of the muckpile. The apparent fragmentation analysed with PowerSieve is also discussed.

Jan 1, 2001

By Rolf Schillinger

Transport of Small Quantities of Explosives Material on Public Roads The transport of dangerous goods on public roads is extensively regulated by EU and national law. The transport of explosive material is not only done by forwarders but also by small companies and private persons with the goal of their own use. The following article tries to explain what is allowed and what is not.

Jan 1, 2010

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 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 Paul Kunze

We have been told many times by legal folks and insurance types about the importance of producing accurate blast reports should you ever get dragged into court. In that venue the investigators will look at the information regarding product type and quantity, it’s distribution among the holes, and delay information in order to arrive at some judgement regarding vibrations or other blast induced phenomena

Jan 1, 2003

By Eric Reale

The New York City Department of Environmental Protection (DEP) is currently building City Water Tunnel #3 beneath the city. The purpose of this tunnel is to improve water distribution to the city and to allow the DEP to inspect the older tunnels and make the necessary repairs. These older tunnels have been in continuous operation since the early 1900's. Construction on the Third Tunnel is planned in four stages. The Nelson Street Shaft, which is the focus of this paper, is part of the second stage.

Jan 1, 1989

By N. Powell, P. Hunt, A. Wetherelt

This paper considers the current methods of analysis employed, the validity of assumptions made and the reliability of results and predictions derived; where appropriate, alternative methods are proposed which are more accurate and can be applied with greater confidence. In regard to data collection, new local blasting data has been analysed and conclusions drawn but, due to the restricted amount of space available, reference to data set A only has been made in the text. The problem of mathematical model choice is considered and results for two and three parameter power laws are compared. The very important matter of parameter determination is discussed fully, with major emphasis being placed on the comparative merits of log-log linear, log-log planar and direct power law regression. Supporting data analysis examples are included. Assumptions regarding the normality of ‘best-fit’ regression model residual distributions are questioned and the reliability of associated safety limit determinations is discussed.

Jan 1, 2003

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