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By Brent Blanchard

An emergency demolition project related to a bizarre plane crash has reportedly set a new world record for the tallest structure ever explosively demolished. On Sunday, April 22, 2001, 38-year old Gilbert Paquette was killed when his singleengine Cessna 150 struck a 1,217-foot tall communications transmission tower while flying in heavy fog over a remote region of upper Quebec Province.

Jan 1, 2002

By Andrew Drake, Mark Burchard, Peter Bellairs

The Astec Bluerock Quarry is excavating an extremely difficult to blast rock type due to its highly variable jointing density that leads to excessive oversize. A drill and blast benchmarking exercise led to eight recommendations to minimise this problem. Quarry personnel instigated a continuous improvement blasting program, that has implemented six out of eight recommendations, resulting in a large reduction in the oversize and increased crusher throughputs for a marginal 7% increase in drill and blast costs. Unit costs have reduced by an estimated 10%.

Jan 1, 1998

By R Wing, D Corkery

"Several mines in the region of Sudbury, Ontario, occur in or near populated areas. In anattempt to examine the effects of environmental changes and blast induced vibrations onhomes in the area, a monitoring study was conceived. The study was conducted fromNovember 1990 to May 1991 in homes located near the 880 Stope at INCO Ltd.'s CopperCliff South Mine."

Jan 1, 1993

By Mike Cammack

Western South Dakota is predominately an agricultural area, with exception of the mining and timber industries in the Black Hills region. With precipitation rates averaging below fifteen inches per year, water is a precious commodity to the livestock industry. There is a constant demand for the construction of earthen water storage facilities (dugouts) to catch snow and rain runoff, or developing natural springs.

Jan 1, 1993

By Charles R. Welch, Charles E. Joachim

Underwater blasting causes not only ground shock but water-shock. Underwater shock attenuates less with range from the explosive source than ground shock and has the potential for killing fish or marine mammals or for damaging marine structures. The collapse and subsequent oscillation of the gas cavity surrounding the detonation can sometimes produce a greater impulse than the initial shock wave from the detonation. The airblast from underwater detonations can range from nuisance levels to damaging levels.

Jan 1, 1997

By Doug Hoy

The scope of the Cliff Avenue Reconstruction Project in Sioux Falls, South Dakota was to widen a two lane highway to five lanes, along with removing and reconstructing both above and below ground utilities located along the project limits. The objective of this paper is to present the blasting techniques used in the rock excavation phase of the Cliff Avenue Reconstruction Project.

Jan 1, 1992

By Roger L. Keller

This paper examines the aspects of differing types of blasting cuts in underground headings with consideration to the reduction of number of holes and costs. At least one comparison study is related where costs per advance meter were significantly improved. The technical aspect of the paper covers a study of the effects of various blasthole delay intervals on resulting crater volume, ground vibration, and fragmentation for six hole V-cuts.

Jan 1, 1989

By Paul Worsey, Robert Sickler

Today, America's mining and construction industries are faced with operating under a condition of reduced profit margins. This makes the implementation of new technology far more sensitive to investment return than ever before. For this reason it is imperative that every effort be made to insure that new equipment and processes be designed to maximize their impact on improved quality, reduction in production cost and enhancement of safety. Using these principles as a foundation, a study was made to evaluate potential automation techniques for the blasting industry.

Jan 1, 1987

By Michael Beattie

A large open-cast limestone mine had its blasting operations severely restricted by the imposition of limiting PPV levels to protect a water pipe-line passing through the mine property. Attempts were made to measure the strains induced in the pipe by ground vibrations, so that a less restrictive blasting limitation could be established on a scientific basis.

Jan 1, 1992

By Conny Postupack, Jim Petrunyak, John Loope

The authors discuss the concepts, engineering considerations, and cost relationships involved in the use of drilling and blasting to accomplish backfilling and reclamation with minimum use of mechanical equipment. The four methods of reclamation now in use are reviewed, and their advantages and disadvantages are noted. Guidelines for selecting a particular method are offered in terms of applicability under varying geologic, economic, and technological conditions.

Jan 1, 1987

By Dale Preece, Stephen Chung

Mining and quarrying industries recognize blasting as the most effective method for breaking and removing large volumes of rock. However, the economics of blasting are often offset by the costly trial-and-error approach. Researchers in the field of blasting therefore design models to help eliminate the number of trials before finding the best feasible solution. Because of the complexity of blasting, a capable model would allow the designer to look at more than one variable at a time so that the most critical factor can be tackled.

Jan 1, 2002

By J L. Jethwa, A G. Gaithankar

The paper deals with a software method developed to design the optimum blast parameters for tunnels and mine roadways for a given set of geo-mining condition without any major discontinuity. The application of the software is presently limited to 8 D-ahaped excavation where inclined hole cut or four-section parallel cut is used with smooth blasting technique.

Jan 1, 1993

By Charles H. Dowding

This paper describes NUVIB, analytical software to digitize, analyze, display, and plot time histories generated by blasting and construction vibrations. It is available in conjunction with a new book on Construction Vibrations (Dowding, 1996) through internet procedures described at the end of the chapter on analytical software These internet based procedures eliminate the need for inclusion of disks in the book and take advantage of the growing electronic communications network. Perhaps more importantly this procedure allows the software to be updated more often than the book is reprinted.

Jan 1, 1997

By James E. Jr Hargroves

With the ever-increasing population growth and modern trend to urban development, the expansion of utilities is a stable, mad or, and constant source of income for many. Blasting is a "necessary evil" to the utility contractor. It can make or break even the most solvent. Housing development expansion and higher treatment of effluents are causing utilities to appear in more congested areas. This paper discusses some of the aspects of utility blasting in the State of Virginia. Consideration is given to bid procedures, pre-blast surveys, record-keeping and practical application.

Jan 1, 1977

By Curtis Garner

Griesemer Stone located in Springfield, Missouri has supplied aggregate in Southwest Missouri since 1946. In 1954 the decision was made to mine the formation and utilize the mined out area for warehouse space. As advancement proceeded, entrances and small diameter air shafts for ventilation were needed and had to be added. It was decided in 1989 to sink an 8' diameter air shaft designed to move 200,000 cubic feet of air per minute with the help of (4) four 50,000 CFM Loren Cook Fans.

Jan 1, 1991

By John R. Coulson

A survey of federal and state licensing requirements for blasters employed on the surface and underground was conducted for the Bureau of Mines. Subdivisions include surface and underground (large and small), metal, nonmetal and coal. The requirements for certification, class of license, available training, types of testing and enforcement practices are discussed. Included are recommendations of some of the industry trade organizations.

Jan 1, 1980

By Paul Muehl, Roger Lawrence

The massive sculpture taking place on Crazy Horse Mountain in the Black Hills of South Dakota, may Be the most unique application of precision blasting techniques in the world today, It is certainly the largest sculpture in history. And it is being carved not by the usual artist implements, but by engineering of explosives. This paper presents a review of the blastingasting techniques and challenges of blast earring the largest sculpture in the world,

Jan 1, 1991

By J W. Edl, F C. Wu

In instrumented model rock blasting experiments in granite blocks, best fragmentation results were obtained when delays between holes were 1 to 2 milliseconds per ft. of burden and when a rectangular shothole pattern was used with spacings larger than the burden. Effective fragmentation in multiple hole blasts seemed to depend primarily on the full development of the crack network around each hole before the charge in the next hole was detonated. The test results showed that simultaneous or almost simultaneous initiation of shotholes in bench blasting resulted in poor fragmentation.

Jan 1, 1975

By Kirstin Girdner, Vicki Seppala, Tom BoBo, John Kemeny, Mike Higgins

Optimal blast fragmentation is fundamental to all phases of comminution. Changes in blast design may affect efficiency and productivity of downstream processes such as crushing, milling and leaching, resulting in cost savings or losses.

Jan 1, 1999

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