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By Virgil L. Lewis

On September 7, 1994, a Burlington Northern coal train crashed into a parked train in the downtown Gillette, Wyoming rail yard. I would like to address two issues in regards to this accident. One, a slide presentation of the damage created by the accident and the resulting required clean-up and two, a simulation of "what if" had there been an explosion during the course of the crash.

Jan 1, 1996

By Pierre Mousset-Jones, Jaak Daemen, Songlin Zhang, Jon Hurley

Most western United States open pit gold mine ore bodies are disseminated deposits. The mineralization is so irregular that it is difficult to visually identify the ore/waste boundary. Blast hole samples are used to interpolate digging polygons based on the pre-blast position of the bench. Dilution caused by blasting is of major concern at these mines, since blast movement can mix and dilute the ore and move it beyond flagged digging polygons established on the blasted rock according to their pre-blast location. Typically, mines try to reach a compromise between blast fragmentation and movement.

Jan 1, 1994

By Sam Oaks, David A. Smith

The new Corridor "G" Federal Highway Project in Logan County, West Virginia is the largest mass excavation highway project currently being built in the United States. Seven sections covering 14 miles of four lane highway and two connector roads will require over 30 million cubic yards of excavation. Construction is on a fast track schedule requiring the contractors to complete excavation and pavement placement in a little over 19 months. The two different general contractors have implemented several innovative Blasting and Excavation Programs to complete this project within the tight completion schedule. The paper expands on some of these unique programs that made the project a reality.

Jan 1, 1994

By D T. Froedge

Before this study was started, literature was searched and cases of alleged water well damage were investigated. Occurrence of ground water in Appalachia is primarily in low yield, fractured, water table aquifers. Four test sites were chosen based on geographic and geologic diversity. Test wells were drilled at each site and base line data on water quality, static water level, and drawdown characteristics were obtained before surface mining commenced. Blast-induced ground vibrations were measured at the surface by the wells at levels up to 5.44 inches per second maximum resultant particle velocity. Measurements made at the bottom of wells indicated that vibrations were considerably attenuated at depths of 140 to 160 feet.

Jan 1, 1983

By John M. Bolger, Keith E. McMaster

Excessive salt fines are undesirable in underground salt mining as they are considered a costly waste by-product. This paper describes an extensive explosive application program conducted at The Canadian Salt Company Ltd, located in Pugwash, Nova Scotia, Canada. The prime objective of the program was to reduce the quantity of fines generated from this company's underground production blasts. The program was known as the "The Fines Reduction Program".

Jan 1, 1996

By Richard Scales, Giles Hellyer, Ian Travers, Dean French, Peter Bellairs

"The Mt Whaleback iron ore mine is located in the Hamersley Province situated about 1OOOkm to thenorth of Perth, the capital city of Western Australia. A small but significant portion of the waste in Mt Whaleback presents problems due to its ability to react with normal commercial bulk explosives resulting in premature detonations, two of which occurred at the mine in 1983 causing great consternation as well as disruption to the mining operation. The techniques and procedures developed to overcome this problem were based on the use of tough durable, acid and heat resistant liners to provide a physical barrier separating the explosive from the rock togetherwith the development of an accurate down the hole remote temperature logging technology. The liner technology was developed due to the inability to produce a reliable inhibited ANFO despite exhaustive mine based testwork."

Jan 1, 1999

By Dale Ramsey

Located in the Chestnut Ridge Mountains of Southwestern Pennsylvania, the Casparis mine named for the founder Kenneth Casparis operated from 1916 until the early 1950. producing crushed stone for construction and railroad ballast. The rock was transported by aerial buckets to a railroad tipple nearly 1000’ (304.80 meters) below the mine. The mine property is now owned by the Pennsylvania Game Commission and is located in the Loyalhanna limestone seam with 4 primary entries that are approximately 40’ (12.19 meters) high by 30’ (9.14 meters) wide and extend over 2 miles (3.22 kilometers) into the mountain.

Jan 1, 2006

By Donald D. Eilers, Pharis E. Williams, Thomas O. McKnown

The Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX) system was developed by the Los Alamos National Laboratory for determining the energy released in a nuclear explosion by measuring the position of its shock front as a function of time. The CORRTEX system, fielding techniques, and the methods and software for data reduction and analysis were developed over a 15 year period with hundreds of measurements made on nuclear tests and high explosive experiments. CORRTEX is a compact, portable, fast-sampling, microprocessor-controlled system, based on time domain reflectometry, requiring only a 24 volt power source and a sensing element. Only the sensing element (a length of 50 ohm coaxial cable) is expended during the detonation.

Jan 1, 1995

By P. D. Katsabanish

Air decking applications are examined using numerical modelling and the AutodynTM code. The mechanism of damage is illustrated and discussed. Air decking is shown to provide advantages over stemming when powder factor is maintained. The current effort does not support reduction of the explosives column in favour of air decking. In a similar fashion, bottom hole air decking increases fracturing in the area of the air deck, compared to when the same volume is occupied by inert materials; however air decking does not appear to reduce the requirement for subdrilling. The apparent discrepancy between the numerical results and some field observations reported in the literature is discussed.

Jan 1, 2005

By Q Liu, P D. Katsabanis

Dust explosions in underground sulphide and oil shale mines result from the detonation of explosives in the blasting operations. Explosive composition, oxygen balance, priming and ideality of detonation were examined theoretically and experimentally in the presence of reactive sulphide dust. It was found that the temperature as well as the chemical composition of the gaseous products of detonation are the controlling parameters related to the explosive. Non aluminized, oxygen balanced emulsion explosives were proven to be relatively safe, while explosives creating combustible products were proven to be extremely dangerous due to the secondary flame they generate. Since a large number of dusty orebodies are often very friable, low density emulsion explosives are also examined for application in production blasting.

Jan 1, 1991

By Ray Jambakhsh, Craig Copping

The St. Lawrence Seaway's Welland Canal has been undergoing a rehabilitation program that requires the removal of deteriorated concrete from the 25 meter high lock walls. Multi million dollar contracts must be completed during the three month winter freeze up. New blast designs have drastically cut the time required for concrete demolition. All blast results including vibration, noise, underbreak, overbreak, scaling and flyrock have been improved and at a lower cost.

Jan 1, 1994

By Pat McLaughlin, J R. (Dick) Daniels

Current practice in establishing quarries in remote areas with hilly or mountainous terrain tends to the use of airtracs (or similar pioneering units) drilling horizontal holes to establish a face, followed by bench development with light excavating equipment. The authors propose the use of a hybrid coyote blast design that incorporates long-round tunneling techniques. This method would, in effect, use down-the-hole (DTH) drills to advance the drift cut to the final depth, allowing longer and more rapid drift advances, and replace the cross-cut drifts with clusters of DTH holes to achieve the same explosives distribution.

Jan 1, 1995

By Rob Farnfield, Mike Kelly, Toby White

There are a variety of sources of dynamic stress which can affect a building and give rise to cracking. A two-storey house, situated in the middle of a surface coal mine was monitored for a period of 30 months to attempt to identify the major causes of cracking. The factors described as environmental include internal and external temperature, humidity, wind speed and direction, rainfall and water table level. These were monitored using a weather station and piezometer and recorded every 20 minutes. The other factors are vibratory and include normal household movement (walking, shutting doors etc.), vehicle vibration and blast vibration. All the significant vibrations in the house were recorded using four sets of velocity transducers and accelerometers.

Jan 1, 1993

By Richard W. Watson, Julius Roth

The Bureau of Mines has recently completed a contract study of the hazards associated with surface mining.! Part of this effort involved an analysis of surface mining accidents associated with blasting activities. For this purpose, 71 reports of accidents investigated by the Bureau of Mines or the Mining Enforcement and Safety Administration (MESA), covering the period from 1962 to 1976, were collected and analyzed. In addition, blasting accident frequencies for the period 1973-1976 were extracted from the central computer files maintained by the Health and Safety Analysis Center (HSAC) in Denver, Colorado. This paper presents a preview of the findings, which are treated in more detail in the final report.

Jan 1, 1978

By Ian A. Niell, Alastair C. Torrance

A joint research programme conducted by BHP Central Research Laboratories and Du Pont Wesfarmers Pty Ltd examined the effect of the size of cast primers on the run up and steady state detonation velocities of ammonium nitrate based explosives as a function of blasthole diameter. Both continuous and point to point velocity of detonation measurement techniques were used. The field trials examined a number of the Du Pont HDP series of primers in conjunction with ANFO, emulsion and watergel explosives. Results indicate that the run up velocity of 187mm diameter ANFO charges is negligible using cast primers as small as 1509. However, emulsion and watergel explosives did exhibit run up in both 187 and 311mm diameter blastholes, independent of the size of primer. This could last from 7 to 10 blasthole diameters.

Jan 1, 1990

By Clarence Zink

Aside from the mechanical properties and process of actual rock breakage, rotary drill bit performance is affected by several “post breakage” items: cuttings size, flushing air pressure, flushing air volume, cuttings load, drill hole geometry, etc. We all recognize that more efficient drilling creates bigger cuttings, more air pressure cleans the hole bottom better, more air clears the cuttings from the hole, and a better hole geometry allows cuttings to escape with a minimum of “regrind”.

Jan 1, 2006

By Paul N. Worsey

Disturbed zones of rock have been measured for blasted highway rock cuttings by Matheson and Swindells of the Transport and Road Research Laboratory (TRRL) of Great Britain. These zones have been shown to be directly attributable to the blasting process and accordingly vary in depth depending on blasting technique. Perimeter blasting such as smoothwalling and pre-splitting has been shown to be effective in reducing the depth of disturbed rock. Although extensive work has been carried out on surface excavations for medium diameter (l00mm) blast holes, none has been undertaken for underground excavations.

Jan 1, 1985

By Joseph Trocino, John Anderson, Stephen Murray

This paper describes the development of LEXFOAM® (Liquid EXplosive FOAM) as a unique low density explosive, and its successful application as an effective tool for "in-place" demolition of landmines and unexploded ordnance. Explosives research using aerosol technology led to the development of LEXFOAM whose components are safely transported and stored as flammable liquids. These components are mixed on site to produce an explosive foam, which enhances safety and minimizes logistical problems. Hand-held, Backpack and Palletized Delivery Systems form a versatile family of dispensing systems to suit any application.

Jan 1, 1998

By Frank Barker

Mining operations present a very different environment to the suppliers of explosives, initiating systems and services, both on surface and underground. Typical hazards include underground movement, air quality, ground stability, moving equipment, and the use of explosives. As contractors to the mining industry we do not have management control over the environment in which our people operate. The hazards and consequent level of risk that our people are exposed to in some mining operations are significantly higher by orders of magnitude than in a normal factory environment. Orica Explosives (and other Explosives suppliers) are continually and increasingly identifying opportunities to partner with customers by adding value through the provision of services leading to a reduction in total mining costs. These services include the provision of a bulk underground loading services, delivery of product into underground magazines, magazine management, value added blasting, conversions, rock-on-ground contracts, and blast management programs.

Jan 1, 2000

By Vilem Petr

Optimization blast design parameters for rounds used at surface mines, quarries or cast blast has taken on a new importance with the increased the cost of the explosives and electronic detonators. This paper addresses the fundamentals of blast design and optimization explosive energy utilized for fragmentation. This laboratory studies shows that one key variable-the strain energy set up in rock mass by blast vibration – can be used to predict the extent of damage done to the rock strata, the degree of fragmentation of the broken rock, and the velocity of the broken rock. It also shows how the dynamic strength of the rock strata is influence the fragmentation size distribution as well as the blastability.

Jan 1, 2008