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By Charles Joyce, William C. Burkle, Dan Murphy

Rare indeed has a major cross country natural gas pipeline met and surmounted such obstacles as the Iroquois Gas Transmission Line from Canada to Long Island, New York. Of the 370 miles long length a fair estimate has been that 1/3 or 122 miles were across rock country. Spread One, Four and Five were particularly difficult. If is estimated that over 75% of the required blasting was on those three spreads. The term "spread" goes back to the old term of describing a ranch.

Jan 1, 1992

Computational techniques in determining particle size distributions after blasting is getting wide acceptance. A well known approach to extract this kind of information from digital images is edge detection. The number of edge points on a given image increase proportional to the increase of the particles on the image. By selecting a conveniently smooth threshold, counting the signed edge pixels may be a suitable metric further used to quantify the number of particles in the image. Here we propose an image processing algorithm together with Adaptive Neuro Fuzzy Inference System (ANFIS) to efficiently count the rock particles with various sizes on a given surface. To determine a suitable approximation for a mapping between the number of edge pixels and the number of particles, ANFIS is a suitable tool. As a trainable classifier ANFIS proved itself as being better efficient approach than other well known multilayer perceptron classifiers. ANFIS is trained by using convenient training data pairs previously experienced from empirically counted sample images. When given a new image containing the particle information of selected surface, the hybrid neuro fuzzy image processing approach provides satisfying performance on counting the correct number of particles up to the given scale of sizes. In this paper an experimantal study for assessment of particle size using ANFIS is presented.

Jan 1, 2004

By George D. Raitt, Rudy Lyon

Until fairly recently, Down-The-Hole (DTH or DHD) hammer drilling was never really a factor in large scale open pit surface mining. It was a method confined to water well drillers, aggregate quarries and limestone mines where the hole size rarely exceeded 6-1/2" (165 mm). Also it was somewhat limited to the harder rock areas such as the North East and South East United States. The trend in the big mining pits for coal, copper, gold and iron, was for the big rotary drill rigs with lots of muscle in pulldown, bitload and rotary torque.

Jan 1, 1998

By Matias Suarez, Diego Zenteno

This paper is aimed to display the new advancements of blasting engineering done in different mining sites throughout the country, associated to electronic sequencing, energy of the explosive and its impact on the fragmented rock. This document explains how to define and implement selective sequencing in the blasting in order to promote the propagation of cracks, therefore impacting positively the productivity through the use of the LaGrange diagram. The LaGrange diagram is a very convenient and illustrative method to present the dynamic behavior associated with wave and crack propagation (Rossmanith. H, 2002).

Feb 1, 2020

By G. A. Walsh, M. Timm, S. M. Geerts

This paper will discuss the effectiveness and the general use of improvised shaped charges. Testing was conducted by the New Mexico Tech Student Chapter of ISEE and held at EMRTC. The first series of tests conducted was to illustrate the performance of different features of the shaped charge. A PVC pipe filled with C4 with no cavity, PVC with an unlined conical cavity, PVC with a copper lined conical cavity and no standoff, and lastly a PVC pipe with a copper lined cavity and a 1.5 cone diameter standoff.

Jan 1, 2010

By R Malo, A Yetter

The use of large diameter blastholes for underground mining began approximately twelve years ago and are now routinely employed in a variety of ore types and stope designs. These large boreholes, ranging in size from 4 1/2 inch to 8 inch diameter, were first utilized in the same fashion as in open pit bench drilling. However, a variety of changes quickly followed in order to accommodate the unique conditions encountered while using a blasthole sloping method.

Jan 1, 1984

By Qingshou Chen, Gongbo Li, Hengqian Ran

A method for safe fracture of rock, concrete and other brittle solid material using dynamic water pressure by explosion is provided. The propagation of the pressure is studied with Allievi water hammer theory. Wave equation and velocity formulas of the pressure propagation are shown. The dynamic water pressure is tested in the lab. The propagation of the pressure is simulated by MMIC-2D. The results of fracturing rock in the lab and on a quarry are presented.

Jan 1, 2000

By K Ramachandra Rao

This paper explains the methodology for assessing the efficiency of rockmass fragmentation by explosive blasting, from ground vibration frequency spectrum analysis of the blast event. Explosives are used in the mining, quarrying and construction industries for fragmenting rockmass to a suitable size. When an explosive charge is detonated, in addition to fragmenting the rockmass, it will also generate ground vibration and air vibrations. Efficiency of a blast depend upon percentage of blast energy wasted in generating ground vibrations and air vibrations.

Jan 1, 1994

By Ron J. Elliott, David G. Otto

This project involved deep blast densification of recent volcanic avalanche debris deposits consisting of a 43 meter thickness of loose clean to slightly silty sand, gravel, cobbles and boulders deposited as a result of the 1980 eruption of Mt. St. Helens, Washington, U.S.A. This project was carried out to enhance the resistance to liquefaction or dynamic settlement of soil deposits under the bridge abutments for construction of the 59.4 meter long South Coldwater Creek Bridge. As this bridge is located close to the Mt. St. Helens fault, it will in all likelihood be subject to earthquakes in the order of 6.5 with expected accelerations of 0.55g. Without soil densification, the bridge would suffer severe structural damage in the event of a significant earthquake.

Jan 1, 1994

By Robert B. Hopler

Hercules Incorporated has developed and introduced a totally new non-electric delay blasting cap system which utilizes a low energy gas detonation to activate the caps. Unlike any other initiation system, there is no hole-to-hole connection other than empty plastic tubing until the blast is to be set off. Only at that time, when all personnel and equipment are in the clear, is the special gas mixture introduced through the tubing. The actual time of firing is completely under the control of the operator, by pressing the fire button on the blasting machine.

Jan 1, 1977

By Neil E. Gehrig

The word "slurry" was used by Dr. Melvin Cook and Mr. Henry Farnam to describe a new blasting agent developed in 1956. This development, along with the development of ANFO triggered the Modern Era of Blasting. We have seen the results, a massive expansion in the commercial explosives industry. Someone once said, "You can't know where you're going if you don't know where you've been." With that in mind, this paper deals to some extent with the origin and development of slurry explosives and then with their future high potential.

Jan 1, 1982

By Calvin J. Konya

The Woodville Lime and Chemical Company Limestone Quarry is located in Sandusky County, Ohio. Fifty years ago, when quarrying began, it was situated approximately two miles from the town of Woodville. Today new houses border the quarry property within 1,500 feet of one of the working faces. During the past two years, the operation has systematically changed the blasting program to achieve better fragmentation, lower costs, and to maintain good relations with the local property owners. This paper will discuss systematic changes made in the blasting program to increase productivity and reduce costs.

Jan 1, 1977

By Don Larson, Gordon Coleman

The United States Department of Energy, through its contractor Lawrence Livermore National Laboratory, has entered into a contract with Alpha-IRECO, Inc. for the emplacement of approximately 2.9 million pounds of a 50% RX-MD emulsion 50% ANFO blend into an underground chamber for initiation to produce the 12 trillion caloric equivalent of 1,000 metric tons of TNT. The detonation will be closely monitored to determine the characteristics of a large chemical explosion for comparison with data collected from previous like-sized nuclear events in the same location. This data will be shared with former Soviet block countries to facilitate enforcement of the various non-proliferation treaties currently being negotiated between the countries.

Jan 1, 1994

By Michael Swisdak, John Tatom, James Tancreto

In 2002, testing was proposed to generate needed data to assist in developing improved explosives safety standards within the US Department of Defense. This testing emphasizes two major areas: (1) full-scale donor/acceptor trials examining debris generation and acceptor response and (2) debris perforation testing of representative roof/wall materials. The full-scale donor/acceptor trials are referred to as the SciPan series. The first three tests in the SciPan series have been completed, as has the first phase of the SPIDER program. This paper describes the status and future of these testing programs, reasons for choosing specific tests, potential benefits, and planning for future phases.

Jan 1, 2006

By Mathias Jern, Ruilin Yang

A blast vibration model has been developed that simulates effects of almost all blast design parameters on the blast vibration peak particle velocity (PPV) from a production blast with multiple blastholes at a given point of interest in the rock. The velocity of detonation (VoD), initiation points, explosive types (density, VoD, energy), charge decoupling, and decking in each blasthole are simulated along with other blast design parameters. The information from signature hole blast vibration and the blast design are the input to the model. The model can be used to assess blast damage in proximity of blastholes as well as far field vibration PPV.

Jan 1, 2019

By Paul Worsey, Braden Lusk, Seokbin Lim

This paper discusses the theory and experiment involved in the discovery of the mechanisms of Linear Shaped Charges, which are much different from those for Conical Shaped Charges. Linear Shaped Charges (LSC) have been assumed to function in the same manner as Conical Shaped Charges (CSC) in the published literature on the subject. Much work has been done on CSC for military purposes, but there is limited information about the mechanics of LSC. Previous theories have cited the formation of a Monroe Jet as the dominant process. The Monroe Effect describes what happens to a target below the charge following detonation of the charge, and prescribes a fluid jet process for penetration. The fluid jet comprised of the liner material is the cutting device in CSC and has been extensively studied. Recent work at the University of Missouri at Rolla (UMR) cutting concrete with LSC has surprisingly shown that there is not a fluid jet process in LSC. After completing several reinforced concrete penetration tests, minimally deformed copper blades were found in the debris. Initially, the blades were suspected to be misfires or malfunctioned charge remnants. However, results were good and blades were found after every single test. Upon closer inspection, the ribbons were found to be folded copper and they were suspected to be the bottom liner of the LSC. A test series was conducted to verify the new theory by experiment.

Jan 1, 2005

By Peter Moser, Mark Ganster, Radoslava Ivanova, Florian Bauer

Blasting accurately in underground drifts and creating a smooth contour requires proper drilling, knowledge about the apparent geology, a well designed blast pattern and ideally a smooth blasting product. These products are usually cartridged explosives with less energy and are charged in the contour holes in order to reduce the energy concentration and therefore the cracking into the surrounding rock. With the development of a new contour blasting system, a device can now be delivered to the industry that that avoids the additional storage of cartridged products when bulk explosives are used. The system consists of a foldable hose that is charged with bulk emulsion, in the same way as the rest of the blast, from the base to the collar of the hole. It centers automatically in the borehole and provides a decoupled charge. The paper describes the system in detail, gives background information on smooth blasting and presents the first successful field tests using the system in the drifts of an underground mine. It shows the advantages of blast results that produce more stable contours that reduce the amount, time and cost for support but also increase safety underground.

Jan 1, 2012

By Eugene Baker

President George Bush signed the Safe Explosives Act (SEA), which amended the Organized Crime Control Act (OCCA) of 1970, into Law on November 24, 2002. As a result of this legislation, new restrictions on who could legally receive or possess explosives in the United States went into effect, resulting in a profound impact on the commercial explosives industry. The law went into effect in two key phases. The first phase, which went into effect on January 24, 2003, resulted in additions to the categories of persons who are prohibited from receiving or possessing explosive materials in the U.S.

Jan 1, 2004

By Mark S. Stagg, Rolfe E. Otterness, Stephen A. Rholl

The Bureau of Mines has developed computer software to study the effects of initiator scatter on all aspects of the blasting process. The software is useful because it is difficult to obtain actual initiator data, particularly the standard deviation which is needed to express initiator scatter. The new software is structured to allow blasters to answer the question: how precise must initiators be to insure a successful blast? Successful is defined statistically in terms of a confidence level. The software can be used with any possible design since there are no restrictions due to size or complexity.

Jan 1, 1992

By Thomas P. Dowling

Since the 1950's, blasting practices have undergone many revolutionary changes. Some of the more radical departures have involved, in addition to high speed drilling equipment, a myriad of new explosives, blasting agents, boosters, initiators, initiating systems and delay devices. The introduction of ANFO in the mid 1950's as a blasting agent seems to have instigated a trend toward the development and use of less sensitive blasting agents. The evolution of slurries or water gels has produced dense, high strength, water resistant products which has further promoted this trend away from the more sensitive, conventional explosives.

Jan 1, 1975