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By John Vynne, John Hutchings

There have been a number of recent technological advances in instrumentation for blasthole drills, and more specifically in drill monitoring and HPGPS guidance systems. Likewise, great strides have been made in the development of drill and blast software systems which are user friendly, while providing far greater capability to accurately design and monitor drill and blast patterns.

Jan 1, 2011

By Sami Kara, Yunseok Park, Seung-Joong Lee, Namsun Hwang, Michael Laing

This study conducts a comparative analysis of construction efficiency. In the first part we compared electronic and non-electric initiation systems, focusing on tunnel contour holes. Field blasting operations were executed across a variety of delays to identify the optimal delay time. This delay for the in-situ rock mass was determined through regression analysis of blasting vibration in contour holes and for overbreak/underbreak. The blasting results with the electronic initiation system using the obtained optimal delay, applied to contour holes, were compared with the results of the non-electric initiation system. The overbreak and underbreak decreased by an average of 2.7 cm and 5.8 cm respectively, by using the electronic initiation system. Moreover, the vibration reduction rate in contour holes region was reduced by 11.9% based on the blasting vibration estimation equation proposed by the Ministry of Land, Infrastructure, and Transport (MOLIT). Underground construction projects have become increasing popular as cities grow in both size and density. This growth severely limits the amount of useable space for new project on the surface, resulting in the decision to build them underground. This new policy however brings into focus the challenge of managing and reducing blasting related vibration due to the proximity of these projects to sensitive structures, utilities and foundations often present in urban environments. For this purpose, we have been required to manage the vibration by reducing the quantity of explosives used per round. Inspired by surface blasting techniques, we applied a decking mode to address and work around this challenge. We present in this paper the first attempt to blast a tunnel face using a decking method and reduce the charging per hole from 6 kg to 3 kg per hole and keep the same advance rate for this tunnel. The results are presented in the third part of this paper. In the second part we present the results of the decking mode in shaft. The use of the electronic initiation system in tunnel construction provides the users an effective tool to improve the overbreak/underbreak and keep the vibration at a low level with a large gain on the overall project schedule and budget. This what we want to demonstrate in this paper.

Jan 21, 2025

By Wayne Rogers, Kell Monro, Arthur Pacunana

The Phu Kham Copper-Gold Operation (PKM) is a large-scale open pit mine located in northern Laos. It was developed and is operated by Phu Bia Mining Limited (PBM) a Lao-registered subsidiary company of Australian incorporated, PanAust Limited. Production commenced at Phu Kham in 2008. Since the second half of 2016, there has been a significant increase in ore hardness and this has negatively impacted the PKM concentrator and resulted in lower SAG mill throughput rates. Over the remaining life of mine, the changing ore body and increase in ore hardness is forecast to continue as the pit deepens and the availability of softer blending ores reduce. To manage this risk, PKM initiated a Hard Ores Management Program to determine the most effective way to improve the mill throughput of harder ores. This involved conducting a number of innovative and process control driven blasting trials to optimize run-of-mine (ROM) fragmentation and other blasting outcomes. From 2016 to 2017, the performance of high powder factor blasting, electronic detonators and fast timing, high velocity of detonation (VOD) explosives, double-priming, and deck blasting, were individually and systematically assessed. The success of each blasting trial was then based on a ‘value for money’ criteria. This criteria is a cost / benefit analysis that weighed-up the additional cost to implement the trial against the measured improvement in mill throughput. Electronic and high VOD 90:10 emulsion:ANFO blasts were determined to have the best value for money, achieving an increase in mill throughput of 54% compared to baseline. This paper discusses how the implementation of an innovative and process control driven blasting trial methodology was able to successfully manage the hard ore challenges at PKM. In addition, this success was achieved without any major cost implications, safety incidents or process plant set-backs.

Jan 1, 2018

By P A. Lang

Canada is constructing an Underground Research Laboratory as part of a comprehensive program to evaluate the concept of nuclear fuel waste disposal deep in stable rock formations. Careful blasting methods have been designed and quality control procedures have been used for the excavation of the access headings in the underground facilities. This paper describes the work done between 1984 December and 1986 December at the second level, 240 metres below surface.

Jan 1, 1987

By Jean-Guy Levaque, Robert Ethier, Ron J. Elliot

This paper presents data gathered during a comprehensive study on the impact of improvements to fragmentation in a major Limestone quarrying operation. The full impacts of gains in fragmentation are tracked through the mucking, crushing, and grinding phases of the operation.

Jan 1, 1999

By John Meuth, Brandon Fryman, P. E. Hoffman, Joshua Ph. D., P. E. Calnan, Josh Ph. D.

Quantitative Risk Assessment (QRA) can be specifically tailored for use by the commercial explosives industry to calculate risk to employees and the public from commercial explosives facilities and operations. This methodology has several advantages over the American Table of Distances (ATD) which is solely a Quantity Distance (Q/D) analysis. While the ATD has remained essentially the same for 100 years, the safety of commercial explosives in storage has increased immensely. However, the concepts behind QRA calculations are not as intuitive and even at the end of the calculations the values of risk must be compared to something. A few regimes for assessing an acceptable level of risk are discussed in this paper. Risk levels for various United States Federal entities and international agencies are highlighted and suggestions for acceptable risk criteria for individuals and groups are provided. Referencing risk levels from normal daily activities is also done in this paper to make relative the accepted risk criteria. This paper presents some relevant individual risks for everyday activities and some scenarios for group risk for comparison. Individual risk is a straightforward concept however group risk is more complicated. This paper aims to clarify these concepts and provide means to communicate them to the public.

Jan 1, 2019

By Jorge Cárdenas, José Luis Hurtado

The critical distance determination test through direct recording for the mine in Phase 03 was carried out in January 2024, and in it the vibration and pressure models were obtained for the Sedimentary breccia unit. The method of obtaining the records is based on the capture of individual pressure waves generated by distant loads, sequenced in periods of 600 ms for easy identification. The test set up corresponds to a variation of that used to obtain the vibration model, and uses 08 wells for loads and 04 for instrumentation. The results apply a safety factor of 1.2 and 1.5, being 16,000 PSI and 13,250 PSI respectively. The values are valid for any distance greater than 5.5 m, this being the minimum established between wells for loads according to the configuration defined in the field, also considering that in 5.0 m of instrumentation the section of the drill hole with the sensor called S1 collapsed. The results of the analysis of the test, generated with Heavy Anfo 82 explosive, with a final density of 1.15 g/cc, are presented. The results of the modeling and generation of the graphs and tables presented show behavior in line with the concept of scaled distance. It is important to consider that in water conditions there is a high impact by the condition, which causes the records to be higher than those expected in dry conditions and present less variability. It is for the above reason that the row corresponding to distance with safety factor 1.5 is declared valid. The results are only valid for the rock analyzed, whose medium is homogeneous and constant in terms of lithological composition and that present similar resistance characteristics, fracture frequency and water table levels. As future steps, the objective is to quantify the increase in pressure generated between wells by analyzing time and sequence factors. This analysis aims to explain the occurrence of dynamic pressure events in areas where critical safety distances are observed.

Jan 21, 2025

By Ron Ketterling

Donna Summer wrote and recorded a song in 1983 with Michael Omartian called, “She Works Hard for the Money.” The song was inspired by her encounter with an exhausted rest room attendant, Onetta Johnson, who is mentioned in the song by name, and featured on the album’s back cover. ISEE President James Daley, in the May/June 2019 in The Journal of Explosives Engineering discussed the Six Pillars related to the ISEE. We will use the Internal Processes pillar to frame this discussion. The Internal Process Pillar includes five separate sub-committees – we will see how this concept applies to both ATF Explosives record-keeping compliance and business process compliance in general. We will discuss electronic and paper record keeping, what works and what doesn’t. We’ll review record keeping in light of those five sub-committees: Audit, Awards, Constitution, Ethics and Planning. You’ll come away with concrete steps you can use to improve your record keeping processes. This paper will show you how to make the hard work of inventory management and ATF record keeping work hard for you.

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 J T. Patterson

The mining, quarrying and construction industries are often blamed for causing damage to residential-type structures when explosives are used. The claim experience for blasting vibration damage has been poor. This coverage is excluded from the Comprehensive General Liability (CGL) policy. To obtain this coverage, the policyholder must meet additional criteria and an additional premium must be paid. The risk management process offers the explosives user a technique for minimizing the risk of complaints and vibration damage claims on his insurance program and his cash flow. Case histories indicate that the vibration damage claims expense may be a lower risk than the risk of interference with production and cash flow. An annotated bibliography on risk management and defense of vibration damage claims is provided.

Jan 1, 1978

By Tristan Worsey, John Henchion, Nathan Rouse, Yannick Lauras

"This paper presents an approach used to plan and evaluate drill and blast trials for a mine that currently mechanically excavates in-situ rock. The document presents the approach used to plan the trials, the key performance indicators (KPIs) that were necessary to evaluate the mining methods, the test matrix used during the trials, and the results of the trials. The trials, which occurred as part of an overall drill to mill optimization project at this site, helped to evaluate various blast designs using fragmentation results,drilling and blasting costs, and downstream costs. This project was unique in that (1) drill and blast methods were trialed on multiple rock types and various bench heights using a range of blasthole diameters and powder factors and (2) the load and haul costs were evaluated using a range of loading equipment, from 66 tonne (73 ton) excavators up to 250 tonne (276 ton) excavators. A ten year net cost financial evaluation of the material extraction alternatives was also prepared for the site management. Ultimately, the process of evaluating the drill and blast trials helped the management decide whether to continue extracting using mechanical methods or to introduce drill and blast methods to extract the rock."

Jan 1, 2017

By Stanley L. Lippincott

A number of Federal and State agencies require formal training for blasters. Federal agencies often specify the need for initial training involving all job responsibilities as well as periodic refresher training to assure adherence to current operating procedures. failure to provide and document such training can result in substantial penalties.

Jan 1, 1995

By J L. Jethwa, A G. Gaithankar

The paper deals with a software method developed to design the optimum blast parameters for tunnels and mine roadways for a given set of geo-mining condition without any major discontinuity. The application of the software is presently limited to 8 D-ahaped excavation where inclined hole cut or four-section parallel cut is used with smooth blasting technique.

Jan 1, 1993

By Bob de Raadt

The main problem in blasting a fly-over spanning a main road is the brief time available for blasting and the removal of the debris, in order to minimize the ensuing traffic disruption in the public highway below. The blasting plan is consequently based on an extreme "time is money" concept, in which speed and public safety are predominant factors. This paper discusses reliable blasting parameters for this type of demolition.

Jan 1, 1984

By Michael Wieland

Three laboratory tests were developed for rating the wave-impact ruggedness of cap-sensitive explosives that are used for blasting in underground coal mines. Destructible pipe fixtures, called simulators, reproduce the shock wave or rift compression registered during the cross-hole wave interactions. The rift-compression fixture was modified to render quasi-static desensitization, when utilized with a remote air supply. Waves that were recorded near charge explosions show narrow pulses resembling underwater shock waves, followed by wide, weak humps, called rift compressions.

Jan 1, 1996

By Eduardo Lozano, Vilem Petr

This paper provides an overview of a new method for avalanche control using a high explosive charge placed at the avalanche runout zone: the case charge technique. This new avalanche control technique is well-suited to mountain roads presenting several advantages over the existing methods: minimum deployment time, low cost, reduced probability of misfires, and decreased operation time in the avalanche danger zone. The research work presented in this paper was conducted via large scale laboratory experiments where the detonation velocity and the blast physical properties were measured. During the charge design, several parameters were controlled: charge mass, diameter, geometry, density, and external confinement. In addition, the effective range of case charges was increased by the use of the Mach reflection for certain topographical situations. Finally, field test results collected by the Colorado Department of Transportation (CDOT) during the 2017 winter season are presented. The CDOT avalanche control crews have adopted the new case charge as the preferred technique in numerous avalanche locations along the Rocky Mountains roads.

Jan 1, 2018

By Eric Kelley

Having been retained as a legal expert for the fatality at the Canberra, Australia project, it made me aware of how good intended blasters profess to be implosion experts. Owners and contractors can be misled by these representations, seeing a video of Directionalized Structures constructed of reinforced concrete may be impressive to watch, but lack sound evidence of the true mechanics of an actual “implosion”; on steel structures more prevalently. If any well intended blaster comes to a determination that he can implode a structure, it should be not be construed he cannot. It should be well investigated that the specific blaster has verifiable experience. What happened in Australia reflects on all end users of explosives. I have heard a direct quote in our project in Alberta, “We don’t want to have what happened in Canberra”. Such a tragedy could have, and should have been avoided. Simple by using the “Right Tool for the Job”. We should sideline egos and economics. Would any competent blaster compromise his or her reputation, company or insurability? More importantly, have an honest conscience knowing that if the proper explosive is available, use it, don’t shortcut it. If possible expand the schedule. Better, yet, examine all avenues before the project, and last, cancel the project. A human life is our best asset and should not be compromised.

Jan 1, 1999

By Jhon J. Silva Castro

Blast vibration records used in mining contain unwanted information in the form of noise due to long-period drifts, background noise, and noise due to the conversion of the analogue signal to a digital signal. When recorded signals from blasting are used to find other physical variables, such as going from particle velocity to acceleration or displacement, the additional information in the vibration signal can result in inaccuracies in the estimation of the peak values and more dramatically, the results in displacement or acceleration can be nonzero near the end of the record. There are different proposed methods to clean or filter the unwanted information from the signal. All of the methods are based on finding the best fit of the record average value (baseline) and then subtracting from the record under analysis to produce the desirable adjustment. Different criteria and functions are used to define the best fit. The function to use will depend on the shape of the record average values. The main characteristic of the baseline function is that it represents a low frequency wave. Such a low frequency wave can be a periodic function or a polynomial expression of nth order. According to the order of the polynomial expression, the baseline correction can be linear, parabolic or high order. In this document the detailed procedure and the results for the baseline correction of a blast vibration record using a periodic function and a polynomial expression of different order is presented. The results show that the drift problem when displacement is calculate using velocity records increases with the increase of the distance from the blast.

Jan 1, 2015

By Tapan Goswami, Lloyd Hain, Geoff Brent

For many years Ramp 24 at Ensham mine in Queensland, Australia has suffered substantial coal loss and damage due to the fragile nature of the coal and problematic geological conditions, which have proved very challenging. In the past various blasting techniques were applied in attempts to improve coal recovery. One approach was to use a shallow throw (cast) blast followed by a separate post-strip blast underneath. Another method was the introduction of the practice known as “baby decking” with the addition of a large buffer of material in front of the coal. However, despite increasing mining costs, none of these techniques adequately reduced coal edge loss and damage.

Jan 1, 2008

By Richard Givens, Thomas Baginski

Technological advancements in warhead designs and implementations have driven the development of arrayed initiation networks of highly accurate, highly reliable, and extremely safe detonators. Recent development efforts have produced advanced Exploding Foil Initiator (EFI) based systems that have been adapted for civilian use in commercial blasting applications.1,2,3,4,5 This novel, high technology system promises multiple improvements and advantages over the manufacturing, transportation, tracking, storage, inventory and field operation of current detonator systems. Ultimately the insertion of this technology would result in fielding a Non-Energetics Based Detonator (NEBD). Insertion of complementary technologies into the detonator’s supporting systems would greatly advance current detonator hardware/software.

Jan 1, 2011