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By John Brulia

"Definition of On-Site Security: All mandatory and non-mandatory, deterrent and loss control measures undertaken by an authorized explosives business tokeep its stocks of explosive materials and precursors from: • (1) THEFT • (2) LOSS"

Jan 1, 2006

By Peter N. Calder, John N. Tuomi

The development of a successful control blasting program for an open pit iron mine in hard jointed rock is described. The objectives and mechanics of control blasting are discussed. Design and implementation procedures, which should have wide application, are given. Small diameter angle hole pre-split blasting, buffer blasting with production holes in front of pre-split lines and in front of strongly defined rock structures, and vibration control of production blasts are dealt with.

Jan 1, 1980

By Ian Bell

This paper investigates fragmentation in an aggregate quarry using the fragmentation-energy fan concept. Six blasts were monitored, located one behind the other in the same quarry area. The rock structure was blocky, the water level and the usage of explosives were variable within and between the blasts. The powder factor above grade was between 0.28 and 0.44 kg/m3 (0.47 and 0.74 lb/yd3). Fragmentation of the plant feed was measured using an online digital image analysis system and three belt scales. The oversize material that was not directly fed to the plant after the blast corresponds to 3‒9.3 % of the total. Data from image analysis was used to build the size distribution in the coarse range (fragments above 120 mm), and the passing fractions at 120 and 25 mm (4.72 and 0.98 in) obtained from belt scales data were used in the range 120‒25 mm (4.72 ‒ 0.98 in) . The non-dimensional percentile sizes between 10 and 90 % for each blast are described through power functions of the powder factor above grade; the model coefficients are statistically significant. From them, using the principles of the fragmentation-energy fan and the Swebrec distribution properties, the fragmentation can be expressed in terms of the powder factor by means of five parameters: the fan focus coordinates and the three parameters of a function of the exponents vs. the percentage passing. The model shows a good capability to describe fragmentation.

Jan 1, 2019

By Malcolm Mellor

Practical procedures that have been developed for pre-split blasting and smooth blasting in common rocks are reviewed systematically. Topics covered include shothole spacing, charge weight per unit length of shothole, decoupling ratio, adjustments for explosive type and rock type, and weight of explosive per unit face area. Relevant properties of frozen rocks, frozen soils, and ice are compared with those of common unfrozen rocks, and appropriate adjustment of blast design is discussed. Interim relationships for the design of controlled perimeter blasting in frozen soils and massive ice are put forward, recognizing that additional experimentation is required. Special problems in controlled blasting of ice are discussed. These include effects of wet holes, delayed removal of burden, and submerged burden. Special attention is given to the cutting of ice islands and icebergs. An Appendix describes an operation in which the face of an ice wharf at McMurdo Sound was trimmed by pre-split blasting.

Jan 1, 1976

By Jim Petrunyak, Conny Postpack

The authors describe in this paper a systematic approach toward reducing coal production costs up to 35% through the use of explosives energy for overburden removal. In this system, explosives are employed to blast as much as 65% of the overburden instantly from highwall to spoil pile, with only the lesser portion requiring removal by dragline, shovel, or loader.

Jan 1, 1983

By G. F. Revey

When rock blasting occurs near new concrete of varying age, engineers representing project owners often express concern that vibration from the blasting will crack nearby concrete. Regulations and/or specifications for civil construction projects usually include particle velocity vibration limits intended to protect concrete. In some cases specified limits are unreasonably low and needlessly restrict and increase the cost of excavation work. This paper discusses how methods of predicting resulting flexural strains caused by blast-motion can be used to develop safe and reasonable PPV limits to protect new concrete. Three case histories demonstrating how these evaluation techniques were used to establish higher PPV limits designed to protect concrete of various structural condition are also presented.

Jan 1, 2006

By Rob Lederer, Chris Batten

Traditionally coal model digital terrain models (DTM) are created from lithological information obtained from broad scale exploration holes. The grid layout and distance between holes means that models do not commonly display local variations of seam dip, faulting and shearing. Due to this, issues can often arise when designing the loading of blast patterns based on potential variances between model and actual coal seam locations. Many sites will often attempt to create more accurate models through the collection of data from coal edge pickups on highwalls and in blast faces, along with information recorded by drillers (touch coal holes) from both production and presplit holes for both the current and previous blasts.

Jan 1, 2012

By John Kemeny

There are many methods used to predict blast fragmentation, including empirical and numerical models, field trials, and experience from ongoing blasting. All of these methods require an accurate measurement or prediction of the rock mass properties. These properties include the characteristics of the rock fractures, including fracture density, friction angle, orientation, length, roughness, fill, etc. They also include the hardness of the intact rock, water content, and other parameters. This paper describes three new technologies that can be used to automatically or semi-automatically obtain rock mass properties: digital image processing, 3D laserscanners, and drill monitoring systems. Each of these technologies is described, including the current state of the art, current limitations, and their future potential. Each of these three technologies has advantages and disadvantages. These new technologies, however, have the potential for providing accurate rock mass information in an automated and real time fashion. This information can then form the basis for a new generation of real-time, database driven blast fragmentation models.

Jan 1, 2004

By Ken Tunnel

In the spring of 2005, the Lake Superior Chapter of the ISEE invited me to speak about raw materials used for blasting, anhydrous ammonia and the effect of this important feedstock on the cost of ammonium nitrate.The invitation was extended because our company is involved in trading ammonia and the production of ammonium nitrate. In a response to a request to update that presentation, it struck me how events such as hurricanes Katrina and Rita can change the landscape of our businesses.

Jan 1, 2007

By R E. Langston, S M. Gazioglu

A preconstruction inventory program was conducted to determine the existing conditions of residential, non-residential and all other structures within 2,000 feet of the blasting limits for a highway excavation site in Asheville, North Carolina. Prior to major production blasting, eleven test blasts were detonated to establish site specific propagation parameters in order to develop contours of maximum allowable explosive charge weights per delay. The method of scaling distance by the square root of charge weight per delay was utilized in developing the contours of allowable charge weights. The charge weight contours were revised during blasting operations as additional vibration data became available. The effects of blast induced vibrations on a nearby water storage reservoir, a nearby vehicular tunnel and other adjacent residential and non-residential structures were observed and monitored over a period of two years of blasting operations.

Jan 1, 1980

By Robert B. Hopler

The Hercudet ? Nonelectric Delay Blasting Cap System has undergone significant changes since the last paper on the subject was presented at the 1978 S.E.E. Conference. The changes have been made to improve reliability of the blasting machine at low temperatures, and to improve efficiency and economy in usage in surface mining. The paper includes examples of the blast design process, details of use of the new in-hole connected cap, and delay patterns which have found use in quarrying and coal stripping.

Jan 1, 1980

By Earl C. Hutchison, Wade C. Hutchison

To effectively evaluate property damage that is claimed to have been caused by blasting activities and in order to lay the proper foundation to build the best legal defense, identification of the actual causation for the damages are necessary. For the past twenty years, engineering personnel from VCE, Inc. (previously Vibration Control Engineering, Inc.) have been evaluating claimed blasting damages with pre and post blast inspections, with analysis of seismic levels, blasting amounts at given distances, and with other engineering considerations. In addition to these evaluations, they have also documented other causes for damages which are of the types that are often claimed as blasting damage.

Jan 1, 1995

By Thierry Bernard

Since the signature hole method principle has been described in the 80's, there has always been a lot of controversy about it. The theory is easy to understand but when it comes to apply it for predicting vibration level, optimizing timing to reduce PPV or shifting frequencies, it’s not always working as expected. Simulations show waveforms that don't make any sense or predictions that are far away from actual results.

Jan 1, 2012

By Julijan Bratun, Joze Kortnik

Production of technical stone is an important economic branch in Slovenia. In 2009, we had 95 dolomite quarries, 27 limestone and 6 silicates quarries, according to the Ministry of Economic Affairs. Together they produced nearly 15 million tons of aggregates. The production in quarries is mostly performed with drilling and blasting method and only a minor part with other method like mechanical mining method.

Jan 1, 2011

By Gungor Tuncer, Ali Kahriman, Abdulkadir Karadogan, Umit Ozer

The environmental problems such as vibration, and air blast are often faced, and discussed on mining, quarrying, civil constructions, shaft-tunnel, pipeline, and dam operations where blasting is inevitable. It is necessary to establish national standards towards to minimize the environmental problems induced by blasting and judicial matters in our country as it is in USA, EU countries and the other developed countries. This necessity and the obligatory of accepting the European Union criteria for Turkey that has started the procedure of joining to EU emphasize the importance of this study. In other words, the establishment of a particular national standard related with this subject is inevitable for Turkey. This will be possible only by studying, applying scientific methods and techniques by the experts.

Jan 1, 2010

By Paul Worsey, Seokbin Lim

In many high explosive applications, the explosives are covered or clad by a metal. This metal cover may serve a variety of purposes including: 1) to protect and prevent the disturbing or misshaping of the explosive during its transportation, handling and use, 2) in many military applications the cover material itself is used to provide a required effect, for example, the shrapnel from grenades, the metallic liner of shaped charges, and the confinement of explosives so they perform optimally, and, 3) in civilian applications in the use of well perforating shaped charges and linear shaped charges used for the demolition of steel structures such as bridges. For these reasons the interactions between the explosives and their covering materials are of great importance in understanding the performance of these devices.

Jan 1, 2005

By Andrew Ritter, Victor I. Montenyohl, Stephen R. Winzer

Thirty-seven open pit production blasting operations have been monitored using high-speed cameras running between 500 and 7000 frames per second. Analysis of the resulting films reveals irregularities in timing including sequencing errors and crowding (holes firing less than 8 ms apart), confirming results of laboratory testing of ms delay blasting caps (Winzer, 1978). Where blasting parameters are otherwise constant and within recommended guidelines (stemming, spacing, burden, etc.), timing problems dominate the overall performance of the blasting operation. Model tests in layered Homalite 100, designed to simulate joint or bedding planes in rock, indicate the importance of the stress waves generated by the explosive in developing the crack network which is ultimately responsible for the fragmentation seen in the resulting muckpile. These mechanisms are strongly supported by high-speed film studies at Pinesburg, Maryland. Experiments in controlling relief in deep shots (where depth approaches the lateral extent of the bench blasted) using borehole geometry and hybrid initiation systems (electronic timer and pyrotechnic delays) were carried out. The results suggest that the 1 me/ft. of burden guideline developed by Bergmann et aI., 1974 is too short, and that much longer times are necessary to optimize fragmentation and muck digability. Longer times are found to reduce noise, vibration, and flyrock.

Jan 1, 1979

By Richard J. Mainiero, Eric S. Weiss

This project investigates the behavior of blast waves from the detonation of high explosives in an underground mine. A series of explosive tests was conducted in the underground and surface facilities at the Bureau of Mines' Lake Lynn Laboratory to evaluate the potentially dangerous effects of blast waves produced by open shooting, blown out holes, or accidental detonations of explosives. Shots of C4 and TNT were fired at the dead end of a 6 ft high by 20ft wide entry, at the intersection of two entries, and on the surface. C4 and TNT were chosen for this research because they exhibit very consistent performance. Behavior of the blast wave was evaluated through recording of the pressure as a function of distance from the explosive detonation.

Jan 1, 1995

By Kevin Dunfield

The Deltadet System is composed of: The Deltadet II electronic Detonator. A Field Terminal to create, modify or simply execute an existing blasting sequence. The radio remote controlled option is composed of a Base Station to program, calibrate and initiate the EDDs plus a Blasting Box to send commands to the Base Station. Blasting lines to connect the EDDs to the Base Station (100m) and Visual Blast software to create or modify a blasting sequence.

Jan 1, 2004

By NA NA

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Feb 1, 2020