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By Art Frye, Lee Pratt, Gaichang Zhao, Greg Newman

This paper will discuss the Wight Pit wall slash at the Mount Polley open-pit copper-gold mine that scavenged a high grade block of ore from two double-benches of the pit wall. The Wight Pit orebody, discovered in 2003, is located in the Northeast of the property with the southeast pit wall approximately 50m (165ft) from the edge of Polley Lake. In early 2009, the Wight Pit was nearing completion while an estimated 150,000 tonnes (165,000 tons) of ore averaging a grade of 1.4% copper remained just inside the southeast pit wall. The ore block started 24m (78ft) above the pit floor and extended up another 48m (157ft) with a 70o plane defining the back of the block.

Jan 1, 2011

By Edward J. Walter

Our modern technology is provided with a unique but flexible power tool in the use of explosives. A by-product of explosives usage is vibration or elastic deformation of the earth which is annoying to the ordinary person and can be damaging to structures. The problem is not new, it is more than fifty years old. Adequate vibration standards have been developed so that blasting programs can be properly planned and safely executed. Changes in our social culture have somewhat changed the emphasis in blasting vibration from damage considerations to the much lower level of citizen annoyance. Vibration codes based on this level will be highly restrictive and prohibitively costly. Cooperation is urged between operators, community officials, agencies at all levels,and consultants to see to the development of sound realistic vibration codes.

Jan 1, 1975

By Dale Preece, Stephen Chung

Development of DMCBLAST-3D is continuing and now includes the capability to simulate the detonation of multiple blastholes in multiple rows that make up a conventional bench blast, either in a rock quarry or a surface coal mine. DMCBLAST-3D is a three-dimensional extension of the proven twodimensional rock blast modeling code, DMCBLAST. DMCBLAST has been under development since 1987 and has successfully predicted the physics, mechanisms and results of a number of different types of rock blasting including, coal mine bench blasting, mineral mine choke blasting and underground stope blasting. Substantial effort has gone into the qualification and verification of DMCBLAST by comparing computer code predictions with real blasts in the field. Comparison with field data has also provided significant guidance to the development of the code.

Jan 1, 2002

By Herve Duplaine, Charles H. Dowding

Calculation of response spectra for blast induced vibrations is necessary to fully understand and in some instances comply with frequency or distance related safe blasting criteria. Fortunately, micro-computer systems costing less than $5000 (such as that described herein) can be programmed to calculate response spectra. This system will calculate response spectra from paper as well as FM tape records. It both digitizes (prepares the record for computer calculation) as well as calculates. Programs for the calculation have been written in BASIC, an easy to understand language used with word processors. In addition to describing the equipment and operation of the micro computer the paper will discuss the process of and rules for digitization, use of the computer for record production and will present a simple physical model for understanding dynamic structural response.

Jan 1, 1984

By Alain Duchesne, Dominique Fonfrede, Alan Broca

The technique involves the removal, in one piece, of an unwanted concrete pile section, exploiting the principle of crack propagation induced using gas pressure. The device, or pod, is made of a container in which an over-pressure is generated. After a predetermined time delay of 72 hours, gas and pressure are produced by the reaction between a calcium base chemical and water.

Jan 1, 2012

By David Harrison, Edward J. Walter, Meitra Ferek

A pre-blast survey can be a great tool in the prevention of blasting complaints and subsequent damage claims. In today's highly competitive industry, we are always looking for ways to become more cost effective. This paper investigates the importance of pre-blast surveys not just for regulatory compliance, but as an overall long term cost cutting and public relations tool.

Jan 1, 1995

By John T. Day, Lex L. Udy, Mark L. Thomas

When we consider that the purpose of blasting is to fragment rock or ore so it can be subsequently handled and processed, we can see that the cost of blasting, in reality, affects all downstream steps of the mining (and in some cases) production processes. The productivity of all subsequent operations is influenced by the degree of fragmentation of the primary blast.

Jan 1, 1987

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 Timothy Stark

At present blasters are strictly liable under tort law for personal injury and property damage caused by ground vibrations and/or air overpressures. The application of strict tort liability to vibration and air overpressure damage has resulted in litigation that has hampered and probably will continue to hamper the blasting industry. There are many case histories in which blasters have been sued for the appearance of cosmetic cracking, some of which have involved frivolous claims and marginal expert testimony (Oriard 1999). This litigation has resulted in additional costs to the blasting and construction industries and the American public because there are usually many plaintiffs involved and each case is usually adjudicated separately instead of under a class-action format. It is proposed herein that blasters not be held liable for vibration or air overpressure damages unless their conduct is proven to be negligent. A number of reasons are presented for raising the legal standard from strict liability to negligence including: (1) improvements in blasting technology that allow blasting to be conducted without substantial risk of damage and if damage does occur it is likely to be cosmetic, (2) establishment of conservative ground vibration and air overpressure damage limits for typical structures, and (3) established industry standards for construction blasting.

Jan 1, 2002

By Claude Cunningham

AEL has been developing electronic detonators continuously since 1986. It launched its first system for opencast mining in 1993, and now has two distinct product lines. The path has not been without great difficulty, but the determination to persevere was always buoyed by the strong encouragement of customers who experienced the transformed blasting results, as well as a clear vision of the enormous intrinsic value of the concept. The path of growth to dominant global supplier is traced through the separate application channels of coal stripping, quarrying, massive mining, opencast mining and narrow reef mining, to the first allelectronic detonator demolition blast in June 2001. Reasons for the slow coming to market of this highly desirable concept, which often coincide with reasons for the demise of various other systems, include the difficulty of safely mating electronics and explosives in a low cost environment; the extreme difficulties of achieving proper connection under mining conditions; the rapid rate of evolution of the technology, and the safety concerns raised by various accidents and incidents along the way. ED.s are now established as the way forward and are set to displace other systems in all serious applications. There is place for both programmable and pre-set delay systems.

Jan 1, 2002

By Corry Goumans

Photos 1 - 4 – Chris Elliott is a rock slope supervisor on a construction project east of Seattle, Washington. His job is to look after a “two man” scaling crew working on the rock bluffs some 300 feet in height along the I-90 interstate just east of the town Hyak. The Washington State Rock Engineers noticed a very large mass of unstable rock along the upper rock face and asked us to take it out. Chris is loading explosives in 1½" ” holes that are 8 to 10 feet deep by 40 feet long with 1¼” x 8” power primer on the unstable rock mass that is about 300 feet above the new road construction. I-90 runs east and west longside the new construction note the containment fence and the ship containers along the highway for protection and Lake Keechelus in the background.

Jan 1, 2014

By Li Jianjun, Zhang Xiaozhi, Guan Li, Jin Jinzhe

People used to regard emulsion explosives as the safest industrial explosives. But in the process of manufacturing emulsion explosives spontaneous ignitions of the remnant emulsion matrix have happened under the conditions of constant or low temperature. These fatal accidents show both emulsion explosives and emulsion matrix may involve hidden danger. Since the temperature in its production emulsion matrix is high, emulsion matrix is sensitive to mechanic action.

Jan 1, 1998

By J S. Gozon, R R. Britton

Various methods have been proposed over the past two decades to predict the borehole pressure in decoupled boreholes. In an effort to establish which characteristics best accomodate present day explosive effectiveness, a comparision has been made between two explosives. The first displays high detonation characteristics while the second produces gases which continue to fill the borehole and radial cracks for relatively long periods of time.

Jan 1, 1985

By David Harrison, Brian Harrison

The Army Corps of Engineers completed the Charleroi Lock and Dam in 1932. It is located on the Monongahela river approximately 22 miles (35k) south of Pittsburgh in Charleroi, Pennsylvania. It is comprised of a 420-foot (128m) gated dam, and a 720-foot (219m) by 56-foot (17m) land side lock, which provides for a 16.6 foot (5m) vertical lift.

Jan 1, 2018

By Zhang Zhenyu, Wu Xinxia

The blasting quarrying technology of rock material of rock-fill dam is one of the more complex problems in the field of engineering blasting at present. The Kuz-Ram model is not suited to predict fragmentation distribution under the geology condition of Tianshengqiao(TSQ) fist-step power station. The modification of kuz-Ram model is discussed. With reference to the idea of model establishment of Kuz-Ram model and according to the results of experimental blasting in-situ, two fragmentation prediction models-TSQ-1 and TSQ-2 model are presented which are adapted to the particular condition of rock material querying blasting of rock-fill dam with concrete facing of TSQ first-step power station. The rapid judgment method of qualified grade material and the method of optimizing blasting parameters are also presented in this paper.

Jan 1, 1998

By Bryan Papillon, Karl Christopherson

In order to improve vibrations from quarry blasting, a new technique and timing pattern was established and applied to the particular geology. By shooting a single representative borehole one full second ahead of the production blast, a signature waveform can be isolated and analyzed. Multiple productionsignature blasts were performed. Encroaching residences require quarries to adjust their blasting techniques to reduce vibrations and raise frequencies. A signature hole inherently poses problems to quarries. Blasting one single hole from a production bench poses safety issues to wall stability; vibration issues to close neighbors; and budget issues to the quarry operator. Results showed that the new timing pattern reduced vibrations through timing optimization without a loss in quarry production. Therefore, this technique of vibration analysis employing a production-signature hole is successful in creating a timing pattern that meets the quarry’s goals.

Jan 1, 2008

By Satish R. Kate

Explosive is a chemical energy, which on detonation is released instantaneously with extremely high speed and under high pressure. It is used to meet the basic requirement for breaking of rocks. The productivity is the function of Drilling, Explosives and Fragmentation. Thus, the quality of explosives (energy content) is the key to get desired fragmentation. The variation in energy of explosives and volume of rock per hole have direct impact on fragmentation and cost of excavation (drilling and explosive costs). With the application of higher and higher energy content explosives, it is possible to expand the drilling patterns, i.e. volume in cum. per borehole. As such, higher drill productivity and higher production from the given number of holes can be achieved by adopting appropriate energy content in explosives, and suitable drill pattern for getting desired fragmentation.

Jan 1, 1998

By James Ludwiczak

This paper consists of the conduct of a forensic criminal investigation of the components, construction, use, and functioning of two suicide bombs. As the title states, the task was to form professional opinions as to whether the bombs would work, would cause property damage, and would injure or kill. The bombs were created and installed by a defendant in a Federal death penalty case where the defendant’s daughter was killed in a shootout with the West Virginia State Police. The two black powder bombs were placed under the front seats of the defendant’s automobile and were designed to function by the use of a toggle switch connected to the automobile’s cigarette lighter. The forensic work first consisted of an inspection of the remains of the wiring system and bombs at the Bureau of Alcohol, Tobacco, and Firearms Laboratory, in Ammendale, MD. This was necessary to determine and detail the wire diameter and lengths, the lengths and size of the wire used, the type of toggle switch used, the type of containers, the type of rocket motors used to initiate the black powder, the manufacturer and amount of black powder used in each bomb, and the type, wraps, and amount of duct tape used for the construction of each bomb. Using this data, tests were conducted by duplicating the wiring system and the two bombs to insure that the system functioned properly. Each bomb was duplicated and initiated to observe the violence produced when initiated in the open air. Duplicate bombs were placed under the seats of a similar type of automobile and initiated. The purposes of the tests were to duplicate the bombs, to observe the violence of the initiation, and to observe the damages to the automobile produced by the initiation.

Jan 1, 2007

By Norman S. Smith, Troy D. Harris, Richard L. Ash

In open-cut bench blasting drilling boreholes below grade level is normally considered essential to insure toes do not remain. The extra drilling and use of explosive below floor level are not only expensive but on occasion cause serious problems including severe floor damage and excessive ground vibrations. It has been reported that under certain circumstances explosive in the subdrilling has been successfully substituted by broken rock with its associated benefits.

Jan 1, 1978

By G Dean Barrett, Ed Jr Smith, Calvin J. Konya

The purpose of the project was two fold: 1. To determine whether Pyrodex, a propellant, manufactured by the Hodgdon Powder Company, could be used as a substitute for high explosives for presplitting in granite and other materials. 2. To determine if Pyrodex, a slow reacting propellant which produces no stress waves in rock because it reacts subsonically, could cause the rock to crack similar to the results achieved with high explosives.

Jan 1, 1986