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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 Ettore Contestabile, Cameron Thomas

Implosive-type electrical/mechanical connectors such as XECONEX have been used extensively for joining electrical transmission lines. This implosive action of explosives has also been applied to other forms of high energy metal working with excellent results. However, as with many other products, the inherent blast energy of these units has caused some environmental concerns especially when used in proximity to inhabited areas.

Jan 1, 1995

By K Uenishi, H P. Rossmanith, N Kouzniak, A Daehnke

This contribution presents an introduction into that part of the field of elastic wave propagation which is relevant to blasting of boreholes and addresses briefly borehole breakdown and the formation of the fracture network around a borehole which ultimately leads to the disintegration of the rock mass. Phenomena of this kind are encountered in mining and quarrying. Numerical as well as experimental work referring to stress wave expansion from a detonating borehole is addressed.

Jan 1, 1998

By Mark S. Stagg, David E. Siskind, Stephen V. Crun, Willard E. Pierce

The USBM is studying the impacts of low-frequency blast vibrations on residences to assess both response and cracking potential. Complementing coal mining sites monitored in the midwest and east, vibrations were analyzed at a major construction site in southern Florida where potentially serious low-frequency blast vibrations were believed to exist.

Jan 1, 1996

By I. Petropouleas, J. Croll, R. Bassett

A programme of tests on controlled internal explosions to a class of circular reinforced concrete columns, has allowed the relationships between the blast energy and the extent of local damage to be understood. These tests have also demonstrated the important additional effects on the damage levels of preexisting axial loads.

Jan 1, 2006

By Qingshou Chen, Paul N. Worsey

It has been recently argued that rock strength has little effect on the final results of pre-split blasting and is of only minor importance when blasting rock in general. However, it can be shown that the maximum borehole separation for optimal perimeter blasting results with constant borehole and loading configuration is strongly dependent on the tensile strength of the rock.

Jan 1, 1986

By Rahim G. Haghighi, Calvin J. Konya

Fragmentation is the fundamental concern of rock blasting, serving as a measure of blasting effectiveness. Fragmentation is sensitive to the inter-relationship among the design variables which define pattern geometry. Therefore, the objective of this study was to develop a model which represented a confined bench blast and to investigate the movement of burden-rock as the length to burden (L/B) ratio was varied.

Jan 1, 1985

By G Alan Foster

The presence of approximately 600,000 attorneys in the U.S.A. and the determination by the courts that blasting is considered an 'ultra hazardous' activity makes every practical blaster aware that at some time during his working life he will probably be faced with defending himself in court.

Jan 1, 1982

By R Holmberg, P A. Persson

Recent developments in the methods of measuring rock motion close to the contour at the moment of blasting have given an improved understanding of the extent of rock damage caused by different charge systems. The paper presents the new results and the methods of prediction of damage zones which are used in Sweden for the design of contour blasting rounds. A survey is given of the tools and the techniques for smooth blasting that are now used on a routine basis in Sweden.

Jan 1, 1978

By G Alan Foster

Many complaints generated from blasting operations result from the marked human response to ground transmitted vibrations and air blast effects and so many authorities have considered the regulation of blasting in terms of human response rather than, as previously, in terms of preventing damage to structures.

Jan 1, 1981

By C A. "Hawk" Hanger

"The paper that will be presented is an in-depth study of sequential blasting using standardnon-electric shock tube down hole timing along with surface M.S. connector timing.Included also will be a discussion on the advantages in fragmentation, digability, oredilution' and ground vibration versus the common practice of row by row blasting. Alongwith the written presentation, several visual illustrations will be included. The visuals willrefine the actual direction and predicted movement of the shot involved."

Jan 1, 1993

By Ivan Kovac, Pero Marjanovic, Branko Bozic

"The paper deals with results of geophysical survey of the rock masses, and the blasting parameterswhich have effect on the fragmentation in quarries . A relationship between the burden, which is the distance between the charged borehole and the free rock surface, and the velocity of longitudinal waves in the rock mass is established based on measured values for different quarries. It is shown that the drilling geometry can also be detemrined from this relationship."

Jan 1, 1999

By Mark S. Stagg, Stephen A. Rholl

The Bureau of Mines is studying blast delay timing influences on rock fragmentation in a series of tests that started in 3-ft concrete blocks, progressed to 45in-bench reduced-scale tests in massive dolomite, and has now included 22-ft-bench full-scale tests in a thin-to-thick horizontally bedded dolomite. This paper discusses the full-scale test results and how they compared to the concrete block and reduced-scale studies.

Jan 1, 1988

By Rick W. Bellenie, Ronald L. Woolf

The Gregg River mine is located 40 kilometres (25 miles) south of Hinton, Alberta, approximately 330 kilometres (205 miles) west of Edmonton and lies against the Front Range of the Rocky Mountains.

Jan 1, 1994

The breakage mechnism of a spherical charge greatly differs from that of the cylindrical charge used in underground mining. The advantages of the spherical charge could not be utilized until INCO Metals Company, Ontario Division, introduced large diameter holes to their operation.

Jan 1, 1978

By P D. Kasbanis, Lyall Workman

The energy output of an explosive is typically calculated using an equation of state and computer applications. Results are reported as weight and bulk strength, either in absolute terms or relative to ANFO. The effect of the equation of state selected and the assumptions regarding the energy calculation are considered and interpreted for the purpose of blast design. It appears that variations in the heat of detonation which result from the selection of the equation of state and parameters associated with it are not sufficient to significantly affect blast patterns, explosive consumption and costs. However variations stemming from the use of "available energy" associated with a cut-off pressure are significant, suggesting in many cases large pattern expansions. The validity of the various approaches is discussed and blast design results based on the energy calculated by the different approaches are presented and evaluated.

Jan 1, 1996

By Roger L. McCarthy, Ali Reza

The use of an ammonium nitrate-fuel oil (ANFO) explosive in the Oklahoma City Federal Building bombing has led to a renewed interest in using additives during the manufacturing process of ammonium nitrate to render it non-detonable. Suggested additives include calcium carbonate, which is already used in some European countries, and mono-ammonium phosphate (MAP) or di-ammonium phosphate (DAP), which are the primary desensitizing agents claimed in US patent 3,366,468, Method for desensitizing fertilizer grade ammonium nitrate and the product obtained, issued Jan. 30, 1968 (Porter, 1965).

Jan 1, 1999

By Donald H. Matthews

The usual method of dismantling massive concrete formations with explosives, is to totally demolish the entire concrete structure. If any portion of a concrete structure is required to remain in its original form and retain its structural integrity, the use of explosives is usually forbidden and the portion to be dismantled is demolished by mechanical means, using various techniques and equipment that are tedious and expensive.

Jan 1, 1978

By Randall M. Wheeler

Many blasting companies are using simulated production ground vibration waveforms to aid them in the control of their vibration effects. The simulations are typically produced by using a seismograph to record a signature waveform from a single hole shot and subsequently applying the various delays to be used in a proposed production design. The ability of this simulation method to give good results usually depends on three primary factors. These are: 1) the homogeneity of the seismic travel path from hole to hole; 2) the consistency of the seismic energy release per unit of explosive from hole to hole; and 3) whether or not the delays fire as planned.

Jan 1, 1991

By Lee Julian

Ground vibrations generated by mine blasting must be controlled to comply with legislation and to protect sensitive local or site infrastructure. The consequences of exceeding imposed limits can range from negative publicity to structural damage to infrastructure. It is imperative that vibrations are controlled without compromising fragmentation and delivery of blasted inventory. General practice is to reduce the charge weight and the blast size as blasting approaches the sensitive structures; however such an approach results in blasting smaller volumes more frequently which places greater pressure on production to meet their targets.

Jan 1, 2014