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By John Wall

The use of electronic detonators in civil tunnelling applications, to reduce vibration is small firings has been successfully utilised for a number of years. As part of the mining industry’s commitment to reducing blast damage during the development cycle in underground mining applications, a series of development blasts using eDevTM electronic detonators in typical mining applications was conducted in North Queensland, Australia.

Jan 1, 2012

Blasting is a very cost effective method of rock fragmentation but its uncontrolled application often results in excessive damage to the perimeter of an excavation. Several perimeter control techniques are available but tracer blasting is commonly used in Canadian underground mines for overbreak control. This involves tracing a column of Ammonium Nitrate-Fuel Oil (ANFO) with a detonating cord. In order to investigate the techno-economic effectiveness of tracer blasting in perimeter control, a field experimentation was conducted which involved blasting in sublevel caving and sublevel sloping operations, experimental drifting, benching and pipe tests.

Jan 1, 1997

By G F. Baur

Even though the benefits of an effective, perimeter control program in production and development blasting are evident to most everyone involved in the mining industry, there continuer to be only select properties where such a program is in effect and is producing on-going and measurable results.

Jan 1, 1992

By Duncan Chalmers, Rob Nowell, Miguel Araos

Australian underground mines produce in excess of 60 mtpa of coal. Most of these use the longwall method, and they require the use permitted explosives (which are called “permissible” in other countries) for challenges that appear during the day-to-day activities. To obtain the approval for these explosives, they should pass Testing Memorandum #2 (TM-2), which sets out the test required for each category of permitted explosive. These categories are P1, P3, and P5. With P5 being unrestricted use and P3 and P1 have conditional use in underground mines. The TM-2 test was originally set up for NG-based permitted products around 1900. With the closing of NG plants around the world, ammonium nitrate explosives were the natural replacement, and therefore these explosives need to pass the TM2. Australia does have a P1-emulsion based explosive available. For high-risk scenarios (like blasting coal), no P5 explosives are available. The lack of P5 explosives has been prolonged for more than 25 years, since the phasing out of nitroglycerine-based permitted explosive products around the world. The main problem has been that when emulsion based permitted products are tested in the deflagration cannon, the results obtained were not considered in the TM2 criteria and therefore the tests were invalid. A research work on permitted explosives began in 2005 funded by the Australian Coal Association Research Program (ACARP). The aim of the project was to address the lack of P5-type permitted explosive (and, potentially develop them further, i.e., develop safer explosives) and understand the behaviour of emulsion explosive and the results they presented in the tests. Both bureaucratic and technical barriers appeared along the way. On the bureaucracy side, the facility was shut down, reopened, and shut down again. In view of these difficulties, assistance was sought overseas. On the technical side, from the very start the results of the tests when using emulsion-based permitted explosives were not established in the criteria, ignitions occurred for trial samples that were expected to be P5-type, etc. The aim of this document is to present the painful journey in the Australian industry to have a P5-type emulsion-based permitted explosive, for use in UG coal. Also, the technical learning acquired about emulsion explosives and the ignition path of mixtures methane / air will be shown.

Jan 21, 2025

By Kazuyoshi Kawami, Fumihiko Sumiya, Kunihisa Katsuyama, Yuji Ogata, Koichi Kurokawa, Yuji Wada

When explosives are detonated in the borehole where there is an air gap between the explosive charge and the borehole of inner wall, the shock cave in an air gap travelling ahead of the detonation front sill be generated. This shock wave is called the precursor air shock wave (PAS). The explosive is precompressed by the PAS, and as a result of that the detonation failure occur on occasion. This phenomenon is well known as channel effect.

Jan 1, 1994

By Daniel B. Conn, John L. Floyd

PhotoSeis™ is a blast analysis method that combines the advanced technologies of high speed motion picture photography and digital seismology. When fracturing rock with the use of explosive energy, the human eye cannot detect the details of the process due to its short duration. An extended time base is required to accurately quantify the response of the rock mass to the detonation process. This time base is provided by the use of high speed motion picture cameras. The control of ground vibrations and airblast is an important consideration when developing efficient blast designs. High vibration and airblast levels can be an indication of improper design, inaccurate detonators, or adverse geology. Since many factors can elevate airblast and ground vibration, a greater understanding of the site specific response to the blast design is needed that is beyond the scope of simple seismographic recordings. By synchronizing the photographic record provided by the high speed motion picture cameras with the airblast and vibration information from digital seismological monitoring, the Photoseis™ technique can be of great assistance in controlling airblast and vibration and optimizing the use of explosive energy for rock fragmentation.

Jan 1, 1990

By Brian W. Stump

"Seismic waves from explosions can be used to characterize physical processes in and around the source. The quantification of absolute levels of ground motion is important for minimizing impact on nearby people and structures. We contrast work in characterizing seismic radiation from contained nuclear explosions with ground motions from multiple explosion quarry blasts. A physical basedunderstanding of the explosion source function allows prediction and extrapolation to new environments where experimental data may not exist."

Jan 1, 1990

By John Brulia

"Definition of On-Site Security: All mandatory and non-mandatory, deterrent and loss control measures undertaken by an authorized explosives business tokeep its stocks of explosive materials and precursors from: • (1) THEFT • (2) LOSS"

Jan 1, 2006

By THOMAS BAMFORD, Dale S. Preece, Amir Behbahanian, Mick Lownds

An important aspect of blasting is rock movement and final muck configuration. Computer modeling of this process has been done in 2D for many years, revealing insights into the blasting process and enabling some design optimization. Since blasting is inherently a 3D process, 2D modeling misses the 3D aspects of blasting results and can lead to inaccurate conclusions. Software development environments in many fields are evolving in 3D, enabled by steadily increasing computer speed, memory, and software efficiency. These same environments are also available for modeling of many physical processes, including rock blasting. This paper documents the development of 3D blast movement modeling techniques that utilize 3D computational mechanics and modern computing environments to predict explosive induced movement of hundreds of thousands of distinct cubic elements representing the rock mass. Blast induced ore travel and final location can now be predicted with reasonable accuracy and acceptable run times. The importance of Energy Partitioning was documented and demonstrated by GEM-2D (Geologic Element Motion) at the ISEE conference in 2024. This software is titled GEM-3D and includes this Energy Partitioning capability. This paper documents a GEM-3D example of ore movement during rock blasting and demonstrates ore dilution as well as the final location of different rock types as influenced by the blast.

Jan 26, 2026

By Julia Creasey, Natalie Hodgson, Claire Ward, Craig Davies, Helen Sarginson

"Emulsion explosive producers are attempting to lower the cost of emulsion production by using lowquality ammonium nitrate in emulsion formulations. Low quality ammonium nitrate contains additivessuch as anti-caking agents and crystal modifiers which contaminate the emulsions causing instability. This presents a need for an effective emulsifier that will maintain emulsion stability under thesechallenging conditions."

Jan 1, 2017

By Dale L. Ramsey

The Pinkerton Tunnel Open Cut Project is part of the National Gateway Clearance Initiative improvement project to achieve a minimum of 6.4 meters (21 feet) of vertical clearance along CSX Transportation rail corridor so that double-stacked intermodal railcars can be transported between Mid-Atlantic States and their ports to Midwest Markets in the U.S.

Jan 1, 2014

By Luke Thornton, Jack Janssen

An unconventional drill pattern is used in an aggregate quarry to reduce pioneering costs. The site is the Iron Mountain Quarry, Granite Falls, WA., an aggregate quarry with an annual production of in excess of 1,000,000 tons. The problem is to pioneer a forty acre addition of on top of Iron Mountain. The entire area had a vertical relief of fifty to one hundred feet with no level surfaces. How does one achieve the minimum cost?

Jan 1, 1997

By S. Geerts, J Davidson

The purpose of the experiment was to determine detonation characteristics of various improvised explosives. The test consisted of detonating a pipe filled with an explosive compound inside of a plywood arena. The pipe will be located in the center of the arena to ensure even distribution on the witness panels. Details on pipe dimensions, weights of the pipe and explosive, and the density were recorded prior to testing for use in the model calculations. The same size pipes were used throughout to minimize the variables inherent in testing. The plywood witness panels will capture the fragments so that penetration data was obtained, primarily the surface area of impact and depth of penetration. Through the use of the penetration data in conjunction with a mathematical model the original fragment velocity was determined. The mathematical model was developed to measure lethality of fragments from explosives and was modified to determine the original fragment velocity instead. From this model other variables such as the Gurney velocity were calculated. This test was done with an explosive compound that was commonly found, and numerous improvised compounds. In order to guarantee accurate data all of the explosives used for testing were cap sensitive, to eliminate the need for a booster charge which would introduce many unknown variables. The one common explosive compound that was used was C-4 which has known data in order to show accuracy of the model and calculations. The other 5 compounds chosen will not have this data as they will primarily be improvised mixtures.

Jan 1, 2011

By Kirk Yeager

All explosive formulations display some sensitivity to heat. A common technique utilized to measure an explosive’s response to thermal stimulation is differential scanning calorimetry (DSC). As DSC analysis is run on quantities of material easily handled in a laboratory setting, and is relatively inexpensive, it tends to be one of the more predominant tools utilized to determine potential thermal hazards of energetic materials. The analysis of energetic materials via DSC provides unique challenges, as both large energy outputs and significant production of gaseous products result from their decompositions. In addition, the unique thermal decomposition characteristics of ammonium nitrate (AN) based materials have also created difficulties in DSC analyses. A wide variety of techniques have been developed to study the decomposition of explosives. Traditionally, sealed glass capillaries were utilized to house samples. Recently, the introduction of specialty cells designed to withstand high pressures has enabled new sampling techniques to be developed. Analyses of explosives with both traditional and “high-pressure” cells will be compared and contrasted. Lessons learned about the application of both techniques towards analyzing thermal hazards such as incompatibilities will be presented. Inconsistencies in the results displayed during analyses of AN-based explosives will be highlighted. Recommendations on the best approach for analyzing the more problematic AN formulations will be given.

Jan 1, 2000

By Chuck Kliche, Bill Clements

This paper relates some of the experiences, good and bad, of blasting adjacent to residences of the primary author during his 15+ years of field blasting in the Northern Great Plains region. During this highly-rewarding blasting career, the author has become aware of two major issues in residential blasting: 1) What we call “Risk/Reward Ratio.”Some questions that must be asked by the blaster prior to taking on any blasting job include: - Can we eliminate or minimize the risk? - Is the reward worth the risk? - Do I have a measure of “nervous confidence” about the shot? 2) Public Relations. Two key elements to public relations are: - Notification - Education All the education in the world to the adjacent populous of what’s happening, of blasting in general, or of what to expect from the blasting does little good without notification. Good public relations is a key to controlling the cost of liability in a litigious society.

Jan 1, 2009

By Mark A. Williams, James D. Humphrey

Without question, draglines are one if not the most effective tools available to the surface mining industry for overburden handling. With few moving parts and a two- or threeman crew, this machine silently sits and chews into millions of yards of overburden annually. A 100 cubic yard machine operating for 30 years will excavate three-quarters of a billion yards of material during that time. That is 750,000,OOO yards of material!

Jan 1, 1990

By Isaac E. "Chip" Harris

Any contractor who agrees to supply materials or to perform services for a sum, is well aware of the importance of proper pre-bid information. Being able to properly plan costs and methods results in profits that allow the contractor to prosper. The paper discusses procedures used in estimating pre-bid cost; in particular, drilling and blasting cost for highways, dams and general construction projects. It breaks cost down into five categories and relates them to a total estimate used in bidding and budgeting a construction project.

Jan 1, 1975

By Chris Breeds, Larry Leone, Jerry Wallace

Project Owners typically require General and Detailed Blast Plans when blasting close to important structures and specify the maximum allowable peak particle velocity for each potentially affected structure. Low, residential level PPV limits may be specified which significantly restricts the potential for blasting to be effectively used. Contractor’s responding to these contract conditions typically cite historic case studies which may, or may not, apply to the specific situation and/or types of structures for which limits have been set. A long submittal cycle typically follows.

Jan 1, 2010

By W G. Szymczak, Leslie C. Taylor

The University of Maryland (UMD) has conducted a series of small-scale tests using explosive charges buried in saturated sand. Twelve different combinations of depth of burial of the charge and height of the target plate above the soil were tested. The target plates did not deform plastically. High-speed video was used to track the motion of the plate. The video data are analyzed to determine the position and velocity of the plate as a function of time. The results of this analysis are compared with computations performed at NRL using the BUB2D computer code. This code treats the saturated sand as an incompressible visco-plastic fluid which yields according to a Drucker-Prager (frictional-cohesive) yield surface. Comparisons of simulations with experiments are presented. In the cases examined so far, the velocity grows very quickly to a peak and then slows, first with a deceleration greater than one “g,” which then transitions to an approximately one “g” deceleration. An analysis of air drag on the plates has shown that its effect is negligible in the time span of interest. In all cases in which the BUB2D code can be applied, the computations compare favorably with the results of the data analysis. This suggests that the code and model used in the computation are properly capturing the physics of the interaction between the soil and a non-deforming plate.

Jan 1, 2007

By Terry Matts, Bruce Ripley, Clark Fletcher, Paul Rapp, Stan Holtby, Jim Dent

The Stave Falls Project of BC Hydro, situated 65km east of Vancouver, BC, Canada, involved the construction of a new two-unit 9OMW hydro-electric facility to replace an existing powerhouse. The final phase of the intake excavation consisted of a plug blast to break the channel through into Stave Lake. The plug consisted of a rock and till wall topped with a fill cofferdam, about 51m wide and between 8 and 12m high. Total rock volume was approximately 2600m3, overlaid with about 4600m3 of till/fill. This paper describes the methodology and practical techniques used in planning and loading the blast, and the precautions taken to protect the new and existing structures and equipment. Blasting of the plug by the normal method using downholes would have required the placing of extra fill and much drilling through casing, so the contractor made the decision to drill horizontal holes from the dry, downstream side. Because of poor rock conditions, all 183 holes had to be drilled oversize at 3.5” dia. and fitted with 2.5” id. plastic pipes to keep them open. Hole lengths ranged from 2.5 to 18rn, with a pattern of 1.5m spacing and l.Om burden (with the holes slightly fanned vertically). Because of significant water exposure, a film-packaged emulsion explosive was used, placed using a pneumatic cartridge loader for maximum borehole compaction. The powder factor averaged 1.3kg/m3 (2.21bs/yd3, rock only). An initiation system of combination surface/downhole delay shocktube units was employed, with double and triple redundancy. The maximum number of holes firing in any 8ms window was limited to three (to minimize vibration), while the whole sequence was fully activated before the first hole fired. All shocktube connections were secured and covered over at the foot of the rockface before flooding the excavation downstream of the plug prior to the shot, To protect the powerhouse gates from hydraulic shock, all hole collars were grouted and an air curtain was provided. The blast was completely successful. A maximum vertical displacement of 6m was recorded, but no flyrock was evident. Readings for peak over-pressure and vibration were well below the allowed limits. Mucking proved to be easy, with fine fragmentation, full pull, and no tights.

Jan 1, 2000