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By Michael Burrell

This project involved the protection of an historic landfill located on the site. Construction blasting was for a permanent access road to carry traffic to and from a new metal processing plant being constructed nearby. The landfill contained materials disposed of during the closure of a Phosphorus plant that had previously occupied a portion of this site.

Jan 1, 2012

By S. Mandal, R. Singh

The demolition of structures with explosive though most rapid, safe and efficient requires planned blast design parameters with respect to geometric and strength properties of the structure to be demolished. The paper, here deals with successtil demolition of three old bridge piers by different blast designs. These piers were 11 m tall and very close to the existing bridge, The plan distance of the old piers from the existing bridge varied between 43 m and 14,25 m. The paper also deals with the mathematical concepts for the causes of such action of demolition/dismantling of structures.

Jan 1, 2001

By Ronald W. Roberts

For years, blasters have experienced near-misses, injuries, and yes, even fatalities as a result of the dangerous nature of our business. Yet, some blasters continue to portray the immortal attitude: nothing-would-or-could-ever-happened-to me syndrome. As we all know, that attitude can become disastrous to yourself or colleague(s).

Jan 1, 1996

By R W. Givens

This paper discusses emulsion performance and characteristics. Also presented are pattern design equations by a weight strength method, a "Q" factor method, and a coupled energy powder factor (CEPF) method. Pattern expansion by replacing ANFO with emulsion is presented along with quality control checks for emulsion products. The predicted performance of the calculated burden and the equivalent powder factor as a function of the emulsion percentage, as determined by the three methods, is compared. Field results indicate that of the three methods the weight strength is the moot conservative, the "Q" is overly optimistic, and the CEPF more accurately predicts the effect of coupling and is more consistent with a variety of emulsion and heavy ANFO products.

Jan 1, 1989

By Robert E. Miller

Mass blasting of open stopes and pillars is a normal operating practice at Isa Mine. Three main parameters are used to classify the types of mass blasts. These are type of explosive used, blasthole diameter and system of initiation. Both electric and non-electric initiating systems are currently employed. The advantages gained by large firings are many. More efficient utilization of manpower, due to the concentrated and continuous charging, is achieved. There is no requirement for men to re-enter areas where localised ground conditions may have deteriorated and exposure of ringfirers to stope voids is reduced.

Jan 1, 1980

By S A. Steyn, I P. Douglas

Duvha Opencast is a large South African dragline operation supplying coal to the Duvha Power Station which is operated by Eskom, the state power utility. For Duvha to remain competitive with other collieries, it has proved necessary to continuously examine and investigate methods of reducing costs. With explosives representing a major portion of the total working costs, blasting is an obvious area of investigation.

Jan 1, 1991

By Karl E. Burgher

Accidental explosions occur throughout the world. They can happen at chemical plants, fireworks plants, grain depots, or as a result of collisions involving volatile or hazardous chemicals. It is interesting, as we know as blasters, that we can take two very harmless products and mix them under certain conditions and produce a violent explosion. It is often very difficult for the investigator to determine the magnitudes of blasts after the fact. However, an estimate must be made to settle vibration and airblast damage claims. The blasting consultant or technical representative is often called upon to act as an expert to mitigate these claims.

Jan 1, 1993

By Dave I. McGregor

The Multiple Raise Round Blasting Technique (MRRBT) is a safe, efficient, cost effective method of blasting thee will use existing mine personnel. The MRRBT, developed from the conventional 'drop raise method' style of blasting, can be used for most raise mining applications. Current results using MRRBT indicate no upper limit for the maximum length that a raise can be blasted.

Jan 1, 1994

By Mark S. Stagg, Stephen A. Rholl

As part of its research program to evaluate efficient design criteria for improved blast fragmentation, the Bureau of Mines has developed two computer programs to facilitate data analysis. Results of these two programs are used to better understand the fundamental parameters of blasting for surface mine rock fragmentation.

Jan 1, 1990

By Catherine T. Aimone-Martin, Elena Oana Jacobs, Brent Meins

Accurate pressure measurements during underwater detonations are critical for the protection of structures and mitigating impacts to fish and marine mammals. Current guidelines that limit underwater pressures are based on past studies, many of which used sample rates of 48 and 65 kS/s (48,000 and 65,000 samples per second). These sample rates may be insufficient to accurately record high frequency, sharp rise time blast pressures. As such, pressure thresholds associated with fish and marine mammal injury or mortality may be underestimated, calling into question the pressure and sound pressure level guidelines that govern underwater blasting today.

Jan 1, 2019

By E. Contestabile, B. von Rosen

On August 5th, 1998, a tractor-trailer carrying approximately 18,000 kg of blasting explosives, struck a rock face on the side of the road near the town of Walden, Ontario. Eye-witness accounts of the incident state that there was an intense fire for approximately 30 minutes before the detonation. The detonation caused severe damage to the tractor-trailer, shifted the pavement and caused blast damage to the rock face. A rock fragment was recovered almost 2.5 km from ground zero and a 70 kg piece of an axle assembly was recovered over 1 km from the site. Windows were cracked at distances of almost 3 km.

Jan 1, 2001

Prepare ATF Report of Theft or Loss (ATF Form 5400.5). A Report of Theft or Loss - Explosives Materials must be prepared when it is discovered that explosive materials are missing from inventory. Submit the original to the U.S. Bomb Data Center and keep a copy for your records. The form can be obtained from the ATF Distribution Center or from www.atf.gov. Although the U.S. Bomb Data Center should be notified as soon as possible, Federal law requires notification within 24 hours of the discovery. A full inventory check is also highly recommended (but not required) to locate missing explosives and to prevent future losses.

Jan 1, 2008

By Bin Feng, Xiang Fang, Tao Guo, Fandong Lu

Abstract: Rough set theory (RS) can find useful information from a large number of data and generate decision rules without prior knowledge. Support vector machines (SVM) have good classification performances and good capabilities of fault-tolerance and generalization. To effectively control blasting vibration effect, prediction model of blasting vibration parameters based on rough sets and support vector machines are established. Particle swarm algorithm (PS) is used to dynamically discretize attributes. Then, according to the optimal particle calculated by the PS algorithm, the decision table is established. After eliminating less importance attributes and data, then SVM is trained and established for prediction. The model can deal with both quantitative and qualitative factors such as aperture and cast direction, and analyze their importance to peak vibration acceleration value. The improvement of prediction accuracy is verified by testing data.

Jan 1, 2014

By Jason Baird, Philip Mulligan, Caleb Baumgart

This report details the pressure variances, measured at four pressure sensors placed equidistant from the center of an airburst explosion, as the blast pressure from a single charge expands radially. Many of the empirically derived equations used for predicting the blast pressures of an explosion, assume a point source detonation and that the radial pressure expansion is equal. The authors understand that the equations used to approximate the blast pressure may not have 100 percent agreement with the observed pressure. However, during previous research at Missouri University of Science and Technology (Missouri S&T) the pressure variances had a range of 1,200 psi, between the four pressure sensors placed two feet from the center of a 1/2-pound (226.8 gram) of hand packed C4. The variances indicated that at the close distance from a suspended explosive charge the pressure does not behave as that observed from a point source.

Jan 1, 2014

By Kaushik Dey

Bord and pillar is the most predominant method of wining of coal in Indian underground coal mines. Development heading in coal mines often encounters roof stability problem and results in roof overbreak. Research on this reveals that the blast-induced ground vibration may have significant contribution in roof overbreak, especially, when solid blasting is carried out in the bord and pillar method. Solid blasting, in general, is associated with higher charge confinement due to lack of free face and generates higher ground vibration, which in turn results in excess overbreak.

Jan 1, 2008

By Andreas Gaich

A new 3D fragmentation analysis method for muck piles is presented. It works with aerial imagery from UAVs (drones) and handles entire muck piles with minimum user intervention.

Feb 1, 2020

By Stephen Mansfield, Nathan West, El Khalil Seyed

In October 2017, a multi-bench failure occurred in the east wall of the Guelb Moghrein copper and gold mine in Mauritania. The failure extended 100 m (328 ft) vertically and horizontally and resulted in the sterilisation of ore, but no equipment or personnel were put in danger. The remediation plan successfully removed the failed material and the cutback resumed to a modified pit design, leaving ore reserves behind. In 2021 after completion of mining in another part of the pit, a plan was formulated to develop a narrow cutback behind the failed wall and recover the sterilised ore. Infill drilling defined a resource of approximately 2.9 Mtonne (3.2 Mton) of ore at 0.78% Cu and 0.67 g/t Au at a strip ratio of 5.5:1. The high strip ratio meant that it was necessary to mine thirteen benches of waste, or 156 m (512 ft) vertically, over a two-year period before reaching the first ore, with the cutback only being economically viable if all ore could be depleted at the end of the third year. The high economic risk of the project required a holistic approach to mitigate the risk of another wall failure, by addressing the following areas: 1. Pit Design: with help from an external Geotechnical Consultant, the pit design was optimised to include increased factors of safety, reduced stress points, lower overall slope angles and straight lined walls were replaced with curved walls. 2. Geotechnical Management: the site Geotechnical Superintendent worked closely with an external Geotechnical Consultant to better understand the structural geology. Slope monitoring was improved through an expanded network of prisms, regular in field inspections and the use of a slope monitoring radar. 3. Drill and Blast: new drill and blast designs were developed from first principles, consisting of production, wall control and presplit designs. Blast master polygons and bench development sequences were developed with consideration of the structural geology and the influence of the initiation designs. 4. Mine Operations: improving operational discipline was a critical factor that ensured the accurate execution of drill and blast designs and excavation to bench levels and pit limits. This holistic approach has enabled the safe development of the cutback down to the 936 RL (relative level), two benches below the point at which the previous wall failure occurred. Extraction of ore has occurred from the 960 RL, and due to faster than planned excavation rates, the cutback is expected to be completed ahead of schedule.

Jan 21, 2025

By Robert Hopler

CHAPTER I. DEFINITIONS AND CLASSIFICATIONS. Definition of Explosives. SECTION 1. The term “Explosive” or “Explosives” whenever used in this ordinance, shall be held to mean and include any chemical compound or mechanical mixture that contains any oxidizing and combustible units, or other ingredients, in such proportions, quantities or packing that an ignition by fire, by friction, by concussion, by percussion or by detonator of any part of the compound or mixture may cause such a sudden generation of highly heated gases that the resultant gaseous pressures are capable of producing destructive effects on contiguous objects or of destroying life or limb, and includes all the articles specifically mentioned in Section 3 herein, and all other similar articles

Jan 1, 2013

By S. Hosein, W. Birch, C. Johnson

The widespread adoption of electronic detonators has given rise to the development of linear superposition to control the environmental impact on both third-party properties and residents resulting from blast induced vibrations. Linear superposition has become a very effective tool in the hands of blasting engineers and has enabled aggregate reserves to be accessed that once had to be abandoned. This in turn has resulted in more and more complex blasting pattern to be developed that contain multiple rows and multiple decks all with different maximum instantaneous charge weights of explosives. This is then made more complex by having to consider multiple sensitive locations often with different Peak Particle Velocity vibration limits. This paper is a case study of what did happen when a blast was designed that “pushed the boundaries” of environmental blast vibration design and control, without taking fully into account the fundamental geophysical properties of seismic waves. The resulting blast design caused a greatly enhanced s-wave to be created in a critical direction from the blast pattern. The root cause being the s-waves from earlier detonating decks in the blast pattern arriving within 2 milliseconds of decks detonating later in the blast pattern. 209 individual decks were fired in the blast pattern of which 41 pairs of decks arrived at the observation location less than 2 milliseconds apart when taking into account the s-wave speed and direction. The lesson to be learned when using electronic detonators to limit ground vibrations from complex blasting patterns, is that it is just not good enough to look at the planned firing times, a professional blasting engineer must also understand the likely interaction of the various seismic wave types created and their combined impact on any given monitoring location.

Jan 1, 2024

By Jesús V. Saccsa, Kenji B. Loayza, Erick M. Condori, Jorge A. Velásquez

This research investigates how to reduce manufacturing costs of a safety fuse composed of black powder, replacing its ingredient NO3K by NO3Na for processing, and contributing to minimize costs per blasting.

Jan 1, 2017