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By Thomas C. Palangio

Since the advent of explosives, people have been trying to mechanize the process of loading it into long, narrow holes. Automated loading frees manpower from the arduous task of charging granular, cartridged and slurry explosives. An unexpected bonus of the automation process has been the realization of some valuable side effects such as high throughputs which speed up the loading process and higher loading densities which enhance explosive performance and permit hole patterns to be expanded.

Jan 1, 1990

By Russell Carter, Tom Barkley

"Optimization of blasting is hampered by the lack of inexpensive methods of measuringblast results. Optical methods of size analysis have the potential of creating abreakthrough in size analysis and in overall blast optimization. Attainment of reliablemeasurements hinge on solving a number of shortcomings inherent to optical systems."

Jan 1, 1999

By Timothy Stark

Blasters are usually strictly liable for injury or damage caused by flyrock (trespassory invasion) and blast-induced vibrations (non-trespassory invasion). The application of strict liability to non-trespassory invasions has resulted in significant litigation that has hampered the use of blasting and the blasting industry. Stark (2002) proposes that blasters should not be held strictly liable for non-trespassory invasions but should be liable only if their conduct is proven to be negligent. This change in legal standard was proposed because improvements in blasting technology over the last thirty years allow blasting to be conducted without substantial risk of harm to property and thus the amount of harm imposed by a blast can be related to the level of care exercised by the blaster. It is anticipated that a negligence standard will reduce the amount of litigation because a plaintiff will have a greater burden to overcome. To facilitate the acceptance of a negligence standard by a court of law, this paper summarizes the standard of care using the 1977 Surface Mining Control and Reclamation Act, extensive U.S. Bureau of Mines research, and current blasting techniques, such as blasting mats. It is important for the blasting industry to promulgate a standard of care so a judge can feel confident that blasting can be routinely and systematically controlled and if the legal standard is changed from strict liability to negligence a subsequent judge or jury will be able to evaluate the level of care exercised by the blaster. This paper also suggests that the industry and/or ISEE develop and disseminate a comprehensive standard of care that courts can use to further justify a change from strict liability to negligence and evaluate the standard of care.

Jan 1, 2003

By Ann Barron

“Hurry up” is the latest battle cry at explosives companies struggling to stay in compliance with the ever-growing onslaught of government regulations. The pressure continues to mount on industry professionals who face stiff penalties if their companies fail to comply with the law. Such penalties can range from monetary fines and revocation of blasting permits and licenses, to increased liability for civil claims or even criminal charges.

Jan 1, 2006

By C. Navalkar

Systematic drilling & blasting techniques are currently being viewed in the mining & construction industry as a correct 8z scientific approach for optimization process in rock excavation, as drill & blast costs usually represent major share in total cost of production and also the environmental impacts plays an important role in designing of the operations. Designing a blast is a complex planning task, which for optimization, includes deciding the bench geometry with respect to the rock properties & geology of the area, capacity of the excavators, choice of explosives & detonation method, tiring sequence, etc. Optimization of blast design needs a detailed comprehensive study of all the above intersecting elements. Preblast & Post blast surveys are required for further improvements in blast designs. However, the choice of blast design depends upon the the requisite blasting results opted for and the cost you are ready to pay for the same. The blasting operation, in general, also involves numerous side effects namely, ground vibrations, fly rocks, dust, noise & gas pollution, air blast effect etc. Again these effects can be made tolerable up to a certain extent depending upon the limitations of the environmental obligations as may be specified by the concerned authorities.

Jan 1, 2001

By Gordon K. Jorgeonson

Much of the modelling of blasting operations has been devoted to simulating blasts in open pit mines and quarries . This has been the most obvious application and has been reported in many papers and discussions in the past.

Jan 1, 1990

By David Ziegler

A formal blast plan is sometimes required for projects involving rock excavation. A written blast plan submitted with a bid proposal can also be an important sales tool. A blast plan will cover the basic elements of shot design: hole diameter, spacing, burden, loading, and so forth. Some suggestions are discussed here for additional items or topics to address, including: safety issues, ground control, traffic & site control, public relations, pre-blast inspections, seismic monitoring.

Jan 1, 2003

By James Rowland, Isaac Zlochower, Richard Mainiero, Michael Sapko

The National Institute for Occupational Safety and Health (NIOSH) carried out exploratory laboratoryscale studies to identify factors that may contribute to nitrogen oxides (NOx) production associated with non-ideal detonation of blasting agents. Explosive admixture with drill cuttings, loss of fuel oil in ammonium nitrate and fuel oil (ANFO) from wicking, ammonium nitrate dissolution with water, degree of explosive confinement, ANFO density, and critical diameter were identified as contributing factors to increased NOx production under the laboratory test conditions. Experiments were also conducted to examine the effectiveness of various additives in reducing the NOx production from ANFO, emulsion, and ANFO/emulsion blends. Aluminum powder, coal dust, urea, and excess fuel oil in ANFO formulations were tested and were found to reduce both the nitric oxide (NO) and nitrogen dioxide (NO2) production. Fumes measurements were obtained in the NIOSH underground closed chamber from the detonation of 4.5-kg (10 lbs) charges in schedule 80 seamless steel pipe and from detonations in light weight galvanized steel stove pipe. Some exploratory tests were also conducted with 0.8-kg (1.8 lbs) charges of pulverized ANFO initiated with 0.08-kg (0.18 lbs), 50/50 (Pentolite) boosters (in the NIOSH 12-ft (3.7-m) diameter steel sphere) to measure the degree of fumes production associated with post-detonation oxidation. Ammonium nitrate, emulsion and Pentolite boosters were also detonated in an oxygen-poor environment.

Jan 1, 2002

By Harry Verakis

Flyrock is the second leading cause of all blasting related injuries in surface coal, metal and nonmetal mining operations. It is also a primary cause of property damage, monetary losses and “near misses.” For the period 1978 to 2008 flyrock accounted for 11.6 percent of all blasting-related injuries in surface coal, metal, and nonmetal mines. A large amount of published material has been published on the safety hazard of flyrock, on ways to predict how far rock will travel from a blast, as well as ways to protect mine personnel and neighbors from flyrock. However, flyrock incidents continue to occur resulting in fatalities and “near misses” that could have caused fatalities. It was only good fortune in some instances that no one was in the mine's parking lot or other unprotected area when flyrock rained down or in harm’s way when a large rock punched a hole in the roof of a building or other structure.

Jan 1, 2011

By S. Paul Singh

Rock is a heterogeneous medium, a fact often ignored during blast design. In reality, the rock mass characteristics have a controlling influence on the outcome of a blast. If the optimum blasting results are to be achieved over a range of rock mass conditions, it is prudent to understand the role played by the geological features of a rock mass in producing overbreak around the periphery of an excavation. The field work was performed in a drift located in a geologically dominant rock mass and also included observations and assessment of blast damage at several operating mines. The blast damage was estimated on the basis of the half cast factor. The effect of rock strength, rock quality designation, orientation , frequency and aperture of joints, number and thickness of layers and hydrogeological conditions on blast damage has been described.

Jan 1, 2000

By James Rowland, Marcia Harris, Richard Mainiero

This paper reviews the potential hazards posed by the toxic fumes produced by detonating explosives in surface mining and construction operations. Blasting operations produce both toxic and nontoxic gaseous products; the toxic being mainly carbon monoxide (CO) and the oxides of nitrogen (NO x ). The quantity of toxic gases produced by an explosive is affected by formulation, confinement, age of the explosive, and contamination of the explosive with water or drill cuttings, among others. Techniques to protect workers and the public from the potential hazards of explosive-related toxic fumes are discussed.

Jan 1, 2007

By Brian W. Stump, David P. Anderson

Identification of seismic events detected under a Comprehensive Test Ban Treaty requires a clear physical understanding of the different types of seismic sources including mining explosions, rock bursts, mine collapse and small, shallow earthquakes. Constraint of the operative physical processes in the source region and linkage to the generation of seismic waveforms with particular emphasis on regional seismograms is needed. In order to properly address the multi-dimensional aspect of data sets designed to constrain these sources, we are investigating a number of modern visualization tools that have only recently become available with new, highspeed graphical computers that can utilize relatively large data sets. The results of this study will provide a basis for identifying important physical processes in the source region that contribute to regional seismograms.

Jan 1, 1995

By Kate Satish

M/s Konkan Railways Corporation are constructing 760 kms long rail road in the Western Coastal Region of India. The rail road encounters 75 tunnels through the Western Ghats of India with a total length of 78.35 kms, the longest tunnel being 6.5 kms long. The tunnels are of horse shoes shape having a cross section of about 37 Sq.meters

Jan 1, 1996

By Rachel L. Bauer, Catherine E. Johnson

Explosive demolition involves first, the use of cutting charges to sever a column and second, kicker charges to move it out of alignment. Dynamite is the traditional explosive used in kicker charges as it is inexpensive, easy to initiate, and has a consistent track record of use. Dynamite, however, has health concerns in handling, fragmentation concerns from direct contact on the beam, and availability concerns due to being manufactured at only one location in the continental United States. Recently, water-cased kicker charges have been used in industry, and research has shown that a reduced dynamite mass is possible due to the added confinement, for energetic performance, and the incompressible fluid, which aids in the transfer of explosive energy into beam movement. This research will compare two different explosives, an emulsion (DYNO AP), and binary (HELIX), to dynamite for use in kicker charges, both with and without water-casing. Emulsion is commonly used in rock blasting to create a large push or throw due to its high gas volume production which could translate to kicker charge movement. HELIX is a binary explosive commonly used by the military in breaching charges with water backing. Experimental tests placed kicker charges at the base of a hanging steel column, modifying the ballistic mortar test used to determine explosive power. The study shows that water-casing effectively reduces air overpressure and enhances explosive performance. Among the tested explosives, HELIX showed the most substantial improvements with a 1.8 dB reduction in air overpressure and a 3.2 m/s (10.5 ft/s) increase in column velocity when water-cased. Dynamite and emulsion also benefited from water casing, with decreases in air overpressure (1.1 and 0.7 dB respectively) and increases in column velocity (1.1 and 0.7 m/s (3.6 and 2.3 ft/s) respectively). This research also shows that emulsion is a viable replacement for dynamite in demolition projects, performing similarly in both traditional use and water-cased charges.

Jan 21, 2025

By Reynold N. Hoover

The bombing of the Murrah Federal Building in Oklahoma City, Oklahoma, on April 19, 1995, has once again renewed public debate surrounding the availability and use of explosives in the United States. In the past, Congressional review of explosives regulation has generally followed tragic events such as the bombing of Pan American World Airways Flight 103 over Lockerbie, Scotland on December 21, 1988; the February 26, 1993, bombing of the World Trade Center in New York City; and the delivery of six package bombs to members of one family in several western New York communities, killing five people, on December 23, 1993.

Jan 1, 1996

By N. Powell, P. Hunt, A. Wetherelt

This paper considers the current methods of analysis employed, the validity of assumptions made and the reliability of results and predictions derived; where appropriate, alternative methods are proposed which are more accurate and can be applied with greater confidence. In regard to data collection, new local blasting data has been analysed and conclusions drawn but, due to the restricted amount of space available, reference to data set A only has been made in the text. The problem of mathematical model choice is considered and results for two and three parameter power laws are compared. The very important matter of parameter determination is discussed fully, with major emphasis being placed on the comparative merits of log-log linear, log-log planar and direct power law regression. Supporting data analysis examples are included. Assumptions regarding the normality of ‘best-fit’ regression model residual distributions are questioned and the reliability of associated safety limit determinations is discussed.

Jan 1, 2003

By Kunihisa Katsuyama, Yuji Ogata, Yuji Wada

The one free surface blasting of a concrete block was simulated by Discontinuous Deformation Analysis(DDA) method. Comparing the simulated results with the concrete block blasting experiment, the crack growth and the free surface displacement which were simulated by DDA were observed with a high speed camera.

Jan 1, 1996

By Svatopluk Zeman, Zbynek Akstein, Jiri Pachman, Ahmed Elbeih, Marcela Jungova

BCHMX (cis-1,3,4,6-tetranitro-octahydroimidazo-[4,5-d]imidazole or Bicyclo-HMX) was studied as an energetic component of three different plastic explosives based on three matrices: C4 matrix, semtex10 matrix and silicone matrix. The original plastic explosives, Composition C4 - based on RDX (1,3,5-trinitro-1,3,5-triazinane), Semtex 10 explosive based on PETN (pentaerythritoltetranitrate) and plastic RDX-silicone, were included for comparison. Sensitivity and performance parameters were studied.

Jan 1, 2011

By Steve Dillingham

There are some blasters and blasting companies that just seem to have better safety reputations than others. This is in spite of the fact that they are essentially doing the same type of work under similar conditions. To achieve that enviable safety reputation, it simply comes down to a strong safety culture prompted by a responsibility for others, as well as yourself and your company.

Jan 1, 2003

The VoD of non-ideal explosives depends on the charge diameter and the thickness, strength and sound velocity of the confiner. VoD measurements are made to evaluate explosives for development, quality control and prediction of field performance. In testing, the container is part of the explosive system and affects the measured VoD. Pipe testing in cardboard tubes delivers the best guide to unconfined critical diameter and minimum VoD range, but the thickness of the pipes affects the result close to critical diameter, even in emulsions. PVC pipes are not good for unconfined test work because they provide relatively strong confinement. Care must be taken to select pipes with constant relative pipe area across the range of diameters. Where pipes are used to evaluate the effect of confinement, the ratio of the wall thickness relative to the thickness of the detonation driving zone in the explosive needs to exceed 0.5 to create full confinement and the ratio of the detonation velocity to the confiner wave speed must be considered. Estimates for critical thicknesses are provided from Non-Ideal detonation models. The relationship between confinement modulus and VoD is discussed and indexes are suggested for quantifying the explosive performance.

Jan 1, 2007