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By Mark Bosse

This is a paper demonstrating the use of a fixed wire and trolley system to deliver 2 or 5 lb cast primers (with 2 meter cap/fuse assemblies) deep into avalanche terrain. This avalanche terrain is mitigated using explosives prior to being opened to guests.

Feb 1, 2020

By Johan Svard

"Two years of field testing have shown that blasting results are improved both in surface and underground applications when Nitro Nobel electronic detonators are used. The delay times canbe chosen with an accuracy of 1 millisecond over the entire time range (1 to 6250 ms). Since ordinary.high explosives have detonation velocities of up to 6000 metres/second, these high velocities make accurate and flexible delay times very interesting."

Jan 1, 1992

By Harry L. Siebert

A major Arizona highway project is jeopardizing site safety and security because of the lane rental policy. One million cubic yards of rock must be fragmented to provide two additional lanes parallel to the existing roadway. Traffic is stopped during blasting operations.

Jan 1, 1997

By H. Rossmanith

This contribution introduces the fundamental concepts of wave propagation and fracture mechanics which form the basis of electronic blasting, i.e. precise initiation timing using electronic detonators. The concept of Lagrange diagrams will be frequently used for the calculation of the delay time between blast-holes in a row and rows of blast-holes. The effect of burden and structural geology will be briefly touched. It is found that the advanced blasting technology based on the use of electronic detonators introduces a change of paradigm. It will be shown that knowledge in wave propagation and fracture mechanics is essential for the successful application of the new blasting technique in industry. In particular, the delay time, the wave speeds in the rock mass, the shape of the wave pulse and the acoustic impedance mismatch have become decisive parameters in advanced blasting. Utilizing the wave speed and wave shapes of detonations, large scale tests Utilizing the wave speed and wave shapes of detonations, large scale tests in various countries (Australia, Chile, etc.) have shown that optimal delay timing requires shorter delay times in conjunction with allowing for a wider drilling pattern and the use of a reduced amount of explosives, i.e. a lower powder factor. This seemingly contradictory arrangement is fully justified by using scientific principles in blasting, and converting blasting from an art to a scientific discipline.

Jan 1, 2003

By Carlos Pañura, Michael Geldres, Alejandro Rojas

In this current era of production in large volumes of surface mining, which demands the realization of large-scale blasting, the mining industry must deal with the impact of the vibrations generated by the detonations that are carried out daily in the mines. In this context, the need arises to minimize and control the impact produced by vibrations by determining the interference times of each generated vibration waveform. The vibration waves are produced by the detonation of the explosive charges of each blasthole, analyzing the vibration waves produced by each blasthole, allow us to determine the optimal time between the detonation of each blasthole to reduce the vibrations of the production shot. Once the optimal time is found, it is possible also, to predict the vibration of the production shot (considering times and sequences) using predictive models. The waveform recorded includes information regarding the particle velocity and the dominant frequencies of the vibration. To determine the time between holes, a graph was constructed with the values of the vector Sum VPP (m / s) vs Time between blastholes (s), once the time between blastholes “t” was found, the simulation of the output sequences continued in such a way that, by adding the single waves generated by the blasthole, it gave us a record of vibrations with the lowest level of vibrations.

By Frank Chiappetta, Karl Zipf, Robert Hopler, Brian Stump, Francois Heuze, Bob Martin, Vindell Hsu, William Walter, Craig Pearson

The Comprehensive Test Ban Treaty (CTBT) was accepted for signature at the United ,Nations in September of 1996. It ‘now awaits ratification by its signatories, ~including the United States. After the Treaty is in force, the main concern of the international community twill be to verify that no nuclear test is performed.

Jan 1, 1998

By Cory Loukides, Cathy Aimone-Martin

Blaster training manuals used by the Office of Surface Mining (OSM) and others are outdated and cumbersome. A new approach has been developed using Microsoft PowerPoint with a Visual Basic overlay to produce modules on CD’s that present state of the art blasting techniques. The education modules contain enhanced information on topics such as explosives and initiation products, blast design, drilling, and vibration control. The content is based on safe practices and illustrated with numerous photographs and movies. Review questions, complete with explanations for incomplete answers, enhance the learning process and keep the blaster involved. The benefits of using an electronic format include the ability to continually change and update the training modules as new products, technology and applications become available. In addition, the blaster can work at home in preparation for class work and may reduce the time away from the job. This poster session presentation will allow potential users to view and take part in the evaluation of these modules.

Jan 1, 2004

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 Türker Hüdaverdi, Özge Akyildiz

"Efficiency of blast operations depends on fragmentation, overbreak, muckpile profile anddisplacement, vibration, airblast, flyrock and damage to wall or slope stability. To provide all these conditions at the optimal level, determination of rock mass properties (in-situ block size, joint spacing and orientation) is the very first step during design stage of rock blasting. Image analysis software is used not only to determine the fragmentation level of muckpile but also to characterize the bench face. In this study, an image analysis software was used to determine apparent block size of bench face and to measure blast fragmentation of muckpile. The source of errors and the vital points to be taken into consideration were explained for bench face characterization andfragmentation measurement. Since it provides much better results than previous techniques and it is not intrusive to production process, image analysis technique is considered as one of the most efficient and preferred way for fragmentation analysis. Besides these advantages, there are some weak points of image analysis software. Lighting is one of the most important factors for photographs captured for in-situ block size analysis and fragmentation analysis. Lighting determines shadow formation. In an ideal image, particles are clearly delineated by soft shadows. If shadows are too strong (dark), analysis suffers. Appropriate scale should be replaced onto blast muckpile during site measurements. The location of the scale in image affects the results of analysis. Also, the densityand orientation of discontinuities should be considered during application of image analysis technique to characterize bench faces. In this study, image analysis software was applied in thesandstone, limestone quarries of Istanbul region and an open pit boron mine. All image analysis, evaluations and results were made based on the site measurements."

Jan 1, 2017

By G K. Jorkenson

The SABREX Blast Modelling Program was developed joinlly by the companies of the ICI Explosives Group. of which C-I-L Inc. is a member. SABREX (Scientific Approach to Breaking Rock with Explosives) is a modular computer program which incorporates new technology with a number of tested programs that have been in use world wide.

Jan 1, 1989

By Dennis E. Mitchell

The need to develop and field explosive, pyrotechnic and propellant initiating systems that have high reliability and extraordinary safety requirements has led to the exploration and development of several materials and initiation systems at our laboratories. Our approach to initiating device development encompasses five main areas; energetic materials development , device physics, theoretical analysis and model development and experimental verifications

Jan 1, 1995

By Robert B. Hopler

To understand any technology it is necessary that a thorough background of how we got to the present stage is necessary. To do that with the subject of initiation devices we need to begin many hundreds of years ago.

Jan 1, 1990

By Donald F. Rapp, Thomas E. Brown

The application of commercial explosives in an underwater environment, sometimes referred to as submarine blasting, presents the blaster with a unique set of demanding conditions which require exacting detail in design and application. There are two basic methods for removing rock under water: 1) "the drill and blast method"; and 2) "the dobying method." Because it is a far less effective method of blasting, dobying will not be addressed in this 'paper but suggested criteria can be found in the 16th Edition of the **DuPont Blasters' Handbook" page 371. Some examples of submarine blasting utilizing the drill and blast method include channel expansions, harbor construction, bridge pier footer excavations, utility excavation and demolition work.

Jan 1, 1994

By Nick Lewis

Farce Mining of Texas is a surface coal mine located in Laredo, Texas. Farce mines and sells approximately 600,000 tons /year of bituminous coal. A map showing the location of Laredo is provided in Figure 1. As shown, Laredo is located on the border between the United States and Mexico. The mine property runs to the Rio Grande River, the border between the two countries. Farce pumps water from the Rio Grande for use in their coal preparation plant. Laredo’s climate is quite dry with annual rainfall averaging about 12” per year. Also, due to the southern location, Laredo is quite hot. It is common for the temperature to reach 100” F in March and maintain these temperatures through September.

Jan 1, 1994

By Allen Kinney, P. T. Freeport

This paper presents the methodology for final wall-controlled blasting utilized at the Grasberg Mine. The resulting optimized slopes representa14%and17% increase to bench face angle (BFA) and inter-ramp slope angle (ISA), respectively. The corresponding increase in both copper and gold recovery was more than 40% greater than forecast for each material. The Grasberg open pit mine is located in the remote jungle province of West Papua Indonesia, at an elevation of 4,200 meters(13,780 ft).With a diameter of approximately 3.5km(2.2 mi), anddepthover1.2km(0.7 mi),P.T. Freeport Indonesia (PTFI)has mined billions of tons of rock from one of the world’s largest gold and copper deposits. Grasberg Operation and Engineering implemented a quality driven slope optimization program for the final pushback, with the goal to safely increase recoverable metal through steeper slopes, while utilizing existing infrastructure and equipment. This paper focuses on controlled blasting initiatives, blast monitoring, and as-built slope measurement tracking, although many groups contributed to the success of Grasberg slope optimization. The potential slope optimization area was divided into two sections based on geologic assessment: Area A at radial 200°-270° and Area B at radial 270°-360°. Original slope designs for areas A and B specified ISAs of 51° and 52°, respectively, with all BFAs in the pit at 70°. Through continuous development, collaboration and achievement, the Grasberg final pit accomplished a BFA increase to 80°for all areas, and an ISA increase from 51° to 56°in Area A, and 52°to 60° in Area B.

By Greg Rappard, Francois Holowenczak, James Rickard

The King George V (KGV) Shaft forms part of MTR Corporation Limited (MTRCL) Works Contract 703 extension of the underground West Island Line on Hong Kong Island. The Shaft and the associated adit was the sole access to excavate the running tunnels. Originally during the Detailed Design stage, it was concluded that blasting was not feasible at the KGV Shaft due to the close proximity of sensitive receivers in the form of residential buildings, electrical cables and hospitals. As a result, the Contractor planned to excavate the Shaft using mechanical means with a programme time of seven months. The Contractor appointed a Sub-contractor to analyse the feasibility of excavating the Shaft by blasting. The Sub-contractor reviewed the proposal and recommended the use of an innovative blasting technique that had never been previously employed in Hong Kong. The Sub-contractor recommended the Shaft be blasted using DetNet electronic delay detonator technology, manufactured by AEL Mining Services in South Africa, with an initial 1.5m depth of water ballast covering the blast face. The electronic delay detonators provided initiation accuracy to ensure there would be no overlap between sequentially detonating blastholes. The water ballast makes use of the effect of energy lost through the shock front causing the water to break up into droplets creating a spray dome resulting in the attenuation of the energy imparted into the surrounding rock mass. Various tests have demonstrated that both the maximum overpressure and impulse density are significantly reduced when water of a minimum depth is in direct contact with detonating explosives. This innovative blasting technique reduced the excavation programme by three months, saved HK$5 million in direct costs and totally mitigated the impacts on the public and other stakeholders nearby the KGV Shaft. Peak Particle Velocities (vibrations) rarely exceeded 2-3mm/sec (0.08-0.12in/sec) at a distance of 30-40m (98-131ft) from the blast location and air overpressure levels were reduced below the Hong Kong target level of 120dBL. In total, 24 blasts were fired with an average advance of 1.6m (5.25ft) with an average powder factor of 2.03kg/m3 (0.127lb/ft3) to 1.84 kg/m3 (0.114lb/ft3). The initiation pattern had 5ms between sequentially detonating blastholes and 20ms between adjoining rings.

Jan 1, 2013

By Paulo Cesar Pavan

T&T or Traceability, is a concept of generating, storing and on demand providing information about all traceable items in the supply chain

Jan 1, 2019

By Dale S. Preece

A carefully designed and controlled in-place destruction experiment was performed on a concrete bunker buried in 4.27 m (14 ft.) of soil. The objective was to determine if the explosive charges would collapse the structure in-place without requiring mechanical excavation. Collapse of the buried structure was fi rst attempted by drilling holes in the soil and placing four 13.38 Kg (29.5 lb) Comp B explosive charges at a depth of 2.13 m (6.7 ft.). The confi guration of the charges when detonated was 2.13 m (6.7 ft.) off the top of the concrete roof and 3.66 m (12 ft.) apart in a square pattern. Detonation of these charges created a crater ~4.88 m (16 ft.) in diameter and 2.13 m (6.7 ft.) deep, leaving ~2.13 m (6.7 ft.) of soil covering. Very limited spalling occurred on the ceiling of the concrete structure as a result of detonating these four charges. The second attempt to collapse the structure consisted of placing another single 13.38 Kg (29.5 lb) charge, identical to the fi rst four, near the geometrical center of the bunker roof. This charge was detonated in the soil cover 100 to 200 mm (4 to 8 in.) above the reinforced concrete roof, collapsing it. Due to the collapsed roof and remaining soil cover, the structure had been collapsed in place, requiring no further demolition. A computer simulation of the above explosive destruction scenario was completed using the computer hydrocode AUTODYN with a granular material model to treat the soil and the RHT brittle material model to represent the concrete. AUTODYN accurately recreated the scenario including the slightly damaged response of the concrete structure to the initial four charges and the collapse of the structure resulting from the second single charge close to the roof.

Jan 1, 2007

By Michael D. McGill, Jeff Freadrich

There are many factors which affect the productivity of a front end loader. One of the most obvious is the characteristics of the material being mined. Characteristics such as size distribution, swell factor or heave, and material hardness / abrasiveness will all effect the efficiency of the mucking cycle. The focus of this paper is to look specifically at the size distribution of blasted material, and quantify the effects on loader productivity.

Jan 1, 1994

By Thomas Leonard, Philip R. Berger, Bryan E. Papillon

Bardon Trimount Inc., a large producer of aggregate, crushed stone, and concrete, was experiencing significant public opposition to its five quarries in the Boston area. It was believed by the authors that this opposition could be significantly lessened if the total number of blasts per week were reduced. Although the blasting company at these quarries, Austin Powder Company, contended that this could easily and safely be accomplished by increasing the size of the blasts, regulations precluded this alternative by limiting the total amount of explosives that could be used per blast.

Jan 1, 1996