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In this work, is being described the developing of the study for the demolition by controlled blasting project of a building of reinforced concrete, in the center of a spanish city. Synthetically, it is being analyzed the timing of the fall of the parts of the structure. This documentation is completed with a group of four photographs of the falling sequence and a film about several demolitions and the particular one described in this paper.

Jan 1, 1977

By Carl Hendricks

AQUILA Mining Systems Ltd. is the world leader in drill monitoring, control and GPS based drill navigation systems for the mining industry. This paper will review the general design and application of AQUILA.s drill systems currently in use throughout the world and the key benefits that derive through their use.

Jan 1, 2002

By Mark S. Stagg, Stephen A. Rholl, Steven G. Grannes

A method of determining the fragment size distribution of rock quarry muckpiles using photographic and digital-image processing techniques has been developed by the Bureau of Mines. To assess the fragmentation, photographs and video tapes were taken in both the laboratory and in the field and then digitized for analysis. The fully-automated process uses specially written image-interpretation software which had been developed previously by Bureau researchers to measure irregular taconite ore shapes. The advantages of photographic assessment in comparison with other methods include speed and cost.

Jan 1, 1993

By Petr Mostak, Miroslav Horacek, Miroslav Stancl

Detection of plastic explosives is an important task in the security measures against criminal misuses of this type of explosive. Particles and vapour detectors are basic instruments in this detection. Colour reactions and dogs are also used. Marking system in accordance with requirements of Montreal Convention was developed and applied in full scale production of plastic explosives including Semtex since 199 1. The influence of marking on technology, performance and other properties of plastic explosives is discussed. 2,3 dimethyl 2,3 dinitrobutan is the most popular marking agent which is broadly used. The detectability of this compound is not optimum by some detectors. The substantial effort has been given to development of plastic explosives with controlled shelflife. Some results of this work are presented. Technical and economic aspects of identification marking are discussed.

Jan 1, 2001

By Glenn Ludwig, Stephen H. Chung

Fragmentation has a direct impact on mine costs and productivity. Computer programs have been developed to calculate fragmentation using data on the properties of the explosive, the characteristics of the rock, the rock mass and the blast pattern. While computer models can yield good data, conclusions must be verified. Fragmentation assessment, muckpile surveys or high speed film analysis of rock mass movement are some of the techniques that have been used to confirm blast results. Digitizing photos of the muckpile is now the most common method to assess fragmentation. But it has some drawbacks. Although automatic electronic imaging equipment speeds up the process, the results depend on the photographs. Shadows will distort results. High resolution, black-and-white prints are essential.

Jan 1, 1992

Introduce self – thanks for having me.Indiana program – spent first 15 years of program telling folks how smart we are and to trust us. “We are from the government and we are here to help you.” How well would that go over with you if the IRS invited you in for an audit and that was their openning? Our audience was the same way – not thrilled or inspired. We decided we were the problem – being nice guys just was not enough. We had to learn to communicate with people who did not know us. I am here to share a few things we have learned – and are still learning.

Jan 1, 2007

By Sally Lynn Zadra

"In May, 1994, Echo Bay Minerals - McCoy/Cove Mine petitioned for approval to recycle used oil formanufacturing ANFO. Recycling oil in this way will result in a cost savings for the minesite as well ashaving a positive environmental effect The petition has met the approval of the Bureau of LandManagement, the Nevada Department of Environmental Protection, and has received tentative approval from the Mine Safety and Health Administration."

Jan 1, 1996

By William H. Snyer, Victor A. Sterner

A cache of buried explosives was discovered by ICI Explosives, USA Inc. at one of their sites near Gillette, Wyoming. An intensive investigation conducted by ICI management indicated that nitroglycerin sensitized dynamite might be present. Information also indicated that up to 20,000 pounds of explosives may have been buried.

Jan 1, 1997

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 Elaine Gorham-Bergeron

CAROM is a distinct element, dynamic code developed at Sandia National Laboratories to calculate the motion of rock fragments during blasting.[1] It has recently been improved to incorporate a mechanism for its elements to mimic non-circular rock fragments. With this option, elements stack and move in ways that are characteristic of irregular boulders of blasted rock. In bench geometry, CAROM has been used to examine the possibility of producing variations in muckpile shape due to variations in detonation-time delays between rows. Surprisingly, the shape of the muckpile was predicted to be insensitive to time delays between detonation of rows of explosive, except where the rock fracturing was affected by the time delays.

Jan 1, 1987

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 W Russell

The Hercudet Non-Electric Delay Blasting Cap System provides a means of achieving greater flexibility in the use of delays, using totally enclosed gas detonation circuits which eliminate the concussive effects of detonating cord trunklines in the confinement of access tunnels beneath pillars of ore. This is an account of one such pillar blast.

Jan 1, 1985

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 Jim Daley

SEE is a dynamic organization composed of people from all facets of the explosives industry who are truly interested in the advancement of that industry. I had been a miner at the Homestake Gold Mine in Lead, SD for 12 years when I decided to obtain a mining engineering degree. The mental and economic consequences of that decision were more severe than we had imagined. The joint scholarship program of the Northern Plains and Black Hills Chapters of SEE provides assistance to several college students each year. I was fortunate enough to receive scholarships from this program twice and this assistance helped me and my family with both monetary and psychological support during times of need so that we could stay focused on the goal of obtaining a degree.

Jan 1, 1995

By Mark Mammele, John Bowles

With the continuing rise in the cost of petroleum products and the focus on the increasing use of renewable resources, a readily available, economical replacement for fuel oil in ANFO is the logical next step, and has finally come to realization. This “green” fuel is plentiful, derived from renewable resources, more cost effective and reduces CO emissions. It also increases product density and bulk strength performance. As this unique fuel replaces some of the mass of ammonium nitrate prill, increased savings will be realized proportionally with the increasing cost of ammonium nitrate. Minimal changes are necessary, as this renewable fuel is designed for use and handling with current, commonly used ANFO blending and loading equipment. This proven technology is now in use by commercial operations in the Southwest, providing significant economic benefit with reduced cost per hundred weight of ANFO consumed.

Jan 1, 2008

By David Leidel

A major characteristic that distinguishes modern society from its predecessors is the understanding that events are not driven by the whims of the gods, pre-ordained fate or nature, but are controlled to a greater or lesser extent by the actions, (or inactions), of people. The study of risk assessment is the basis for determining risk or the likelihood of an event occurring combined with the consequences of that event if it does occur. This study is indubitably linked to the mathematics of probability and statistics which permits the quantification of risk. As the Industrial Revolution significantly increased the exposure of persons to new types of energy sources, materials, equipment, and means of more rapid transportation of goods and people, quantitative risk assessment became a vital tool in protecting workers and the general public exposed to these new technologies.

Jan 1, 2007

By Steven V. Crum, Willard E. Pierce

Concern has been raised about the adequacy of current regulatory guidelines designed to protect homes from unwanted blast damage due to low frequency ground vibrations; in particular those with predominant frequencies below 6 Hz. This report summarizes and updates the preliminary results of a continuing Bureau of Mines investigation which will be completed later in 1995. Four structures at four different surface coal mines have been studied by examining their response to ground vibrations created from overburden blasting. House response to ground vibrations with dominant frequencies down to about 3 Hz were recorded. Many of the blasts produced ground vibrations with peak amplitudes above expected crack-producing thresholds. Response motions were compared to those predicted by theoretical single degree of-freedom response models.

Jan 1, 1995

By J Edmund Hay

Previous work by the Bureau of Mines to develop a test for determining the initiating strength of commercial detonators has been modified and extended. Recently reported results by the Bureau used a homogeneous liquid explosive to avoid the complicating effects of inhomogeneities; however, due to the belief that there may be essential differences between the initiation mechanisms of simple liquids and multi-phase mixtures and the fact that almost all commercial explosives are in the latter category, the experiments have been modified accordingly. The acceptor explosive is now a mixture of explosive-grade ammonium nitrate (AN) prills, methanol (MeOH) and nitromethane (NM). An additional change has been the use of the United Nations (UN) cap sensitivity test configuration in which the detonation witness is the degree of compression of a lead block, which is a quantitative measure of the response of the explosive. Results indicate that this mixture has sufficient range of sensitivities to be useful in comparing the strength of commercial electric detonators.

Jan 1, 1993

By Harry Verakis, Thomas Lobb

A great deal of information has been presented and published on the danger from flyrock created from blasting operations. The creation of flyrock is not specific to any one blasting operation. Flyrock is certainly not a stranger to blasting operations conducted in the mining industry and its effects are well known. Flyrock is among the leading causes of mine blasting injuries. Awareness and diligence is the message that must continue to be stressed and followed to reduce the potential for creating flyrock from blasting operations and to reduce the hazard it presents. A recent accident that resulted in a serious injury at a limestone mine in Pennsylvania bears witness to the ever-present danger of flyrock created from blasting operations.

Jan 1, 2007

By Kenichiro Yamamoto, Masaharu Murakami, Toshio Matsuzawa, Yoshiyuki Ikeda

In a series of tests, we examined the dynamic shock resistance of Emulsion Explosive in water and compared it with that of Dynamite and Slurry Explosives. Both the distance between donor and acceptor charges and the delay initiation timing of the acceptor charges were varied. The resistance to dynamic shock varied with the properties of the explosive. In the case of emulsion explosives, there seems to be a certain proportional relationship between the critical detonation distance and the delay initiation timing. Some blasting results with emulsion explosives are described.

Jan 1, 1983