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By Ralph E. Burnham, J. Kelly Ratliff

"The words “dynamite,” “TNT,” “explosives,” and “blasting” typically cause the general public, andjurors, apprehension and fear. Although blasting operations conducted by well-trained, skilled, andexperienced blasters rarely cause damage or injury, the public’s perception of blasting is that it isdangerous, disruptive, and results in damage to nearby properties. As a result, blasting operations have always resulted in complaints, claims, and lawsuits. However, in recent years, the public perception combined with an increase in public opposition, social media, more stringent regulations, predatory plaintiffs’ attorneys, and the application of strict liability to blasting claims has resulted in an increased threat of litigation to blasting companies and individual blasters. Consequently, many blasting companies find themselves receiving more complaints, involved in more litigation, and facing an alarming number of frivolous claims, which can result in increased insurance costs and other financial tolls. Accordingly, today’s blasting companies must be prepared for litigation and take steps to eliminate accidents and claims before the first shot is detonated on a job. The best way to accomplish this is standard operating procedures that incorporate best management practices, industry standards, and regulations in daily operations. This paper outlines some of the considerations that a blasting company should incorporate into its standard operating procedures before, during, and after the shot."

Jan 1, 2016

By Lon Santis

This paper describes several applications of quantitative risk assessment in the management of commercial explosives operations. The Institute of Makers of Explosives’ (IME) quantitative risk assessment software modeling program IMESAFR was used for this analysis. Modeled activities include the unloading of a ship at port, locating a safe haven, and dealing with encroachment on a manufacturing facility. The layout of actual explosives sites were used for the analysis. The risk of fatality is analyzed and shown it can be used to make informed operational decisions for each activity. A study of the risks to individuals from activities involving commercial explosives compared to individual risks from other daily activities or exposures is also presented.

Jan 1, 2008

By S K. Mandal, S Dasgupta

"Damage is classifi ed as loss in the integrity or deterioration in the quality of rock massand is infl uenced by methodology of excavation on the geo-technical properties of rockmass. Overbreak, on the other hand, is the result of damage and is quantifi ed in either of the terms viz., extra mucking, shot-creting, application of extra support system and extension of scheduled completion time. Damage or overbreak in rock mass by the impact of blasting, is generally unavoidable but, the magnitude can be minimized so that it does not deteriorate the quality or integrity of structure. The paper, here, analyses magnitude of overbreak of a powerhouse cavern with respect to different blast patterns implemented at the site. The magnitude of overbreak was analyzed in terms of profi le measurement with the help of laser profi ler and percentage of halfcast markings observed on the periphery rock wall. The paper revealed the impact of decoupling ratio, blast pattern and geometry of blasting patch on the magnitude of overbreak. The authors observed that presence of un-favourable joint pattern or foliation plane along the periphery rock wall couldn’t contain magnitude of overbreak within allowable limit. The analyses revealed that percentage of half-cast markings on periphery rock wall was infl uenced by response of rock towards detonation of explosive and cannot be a single parameter to assess the effectiveness of a blast. The analyses also revealed that magnitude of overbreak for down-stream wall was more than that observed in up-stream wall."

Jan 1, 2008

By Gerald R. Coonan

Laboratory research is being conducted to substantiate suggested levels for voluntary standards on human response to transient vibration. The application of those findings to actual field conditions, however, will be limited because they will not include social and psychological factors existent in the real world. It is necessary, therefore, to examine available empirical information on complaints in an attempt to define the influence social and psychological factors might have on the laboratory results.

Jan 1, 1982

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 Richard A. Dick

Few topics in the blasting industry are more controversial than the proper riming procedure for large-diameter ammonium nitrate-fuel oil (AN-FO) charges, despite the considerable amount of research that has been done both in the laboratory and in the field. The January, April, and June 1975 issues of Emphasis on Blasting contain interesting discussions on priming (5). An ideal primer is one that will surely and efficiently initiate the AN-FO column at the correct location to assure optimum blasting performance. During the 20 years of AN-FO's existence, singlepoint priming, axial priming, multiple-point priming, thermal priming, and shock riming have all been advocated as the "optimum" method. This is not surprising because blasting specialists have often differed on even the most fundamental concepts. To define the optimum primer, we must know what detonation characteristics in the AN-FO column are most desirable. Again, authorities disagree. This paper will discuss conclusions of various studies in an attempt to clear up some of the confusion.

Jan 1, 1976

By W. J. Birch, R. Farnfield

All shock-tube based initiation systems have a time lag relating to the propagation velocity of the shock-tube itself. This paper examines the exploitation of this inherent time lag to achieve delay blasting with accuracies approaching that achievable with electronic systems albeit over a much shorter delay range. The system employed consists of a combination of standard shock-tube, plain detonators and various shock-tube branching components. The accuracy of the complete system depends on the scatter in delay time induced by each component. In order to quantify this scatter a series of trials were undertaken to determine the variability for each component. These trials are described along with a detail statistical summary of the data recorded.

Jan 1, 2009

By J J. F Smith

The application of pneumatically loaded ANFO for underground mining has continued to increase year by year since the technique was first developed and introduced underground during the early 1960's. Improvements in the manufacturing process for explosives grade prills, the design and construction of more efficient AN prill-fuel oil blending equipment, and the introduction of more durable and reliable pneumatic loaders have promoted the wide application of the relatively low cost blasting agent, ANFO.

Jan 1, 1982

By Fumihiko Sumiya, Kunihisa Katsuyama, Yuji Ogata, Yukio Kato, Yuji Wada, Yoshikazu Hirosaki

Smooth blasting technique is widely applied for tunneling road or railway construction in Japan. However, smooth blasting technique often causes problem related to detonation failure in explosive column due to channel effect. Channel effect is attributed to the precursor air shock wave (PAS), which propagates ahead of detonation front in an air channel of borehole. PAS precompresses and desensitizes the unreacted explosive column. The failure of detonation propagation occurs as a result. It was concluded in our previous work that reducing PAS velocity was one of the effective methods for the prevention of channel effect.

Jan 1, 2003

By Joshua Hoffman, Catherine Johnson, Braden Lusk

The practice of dual initiation using precise timing from electronic detonators in boreholes is thought to be beneficial for increasing fragmentation at a desired location in the rock strata. This increased capacity for fragmentation is understood to be a product of both the collision of detonation waves in the explosive column and an increased energy liberation rate, each resulting from dual initiation. In addition, the collision of shock waves from two adjacent blast holes is suggested to improve fragmentation at the location the two shock waves meet, which can be controlled with precise timing. This paper presents the results from scaled laboratory experiments where converging detonation waves and shock waves were studied.

Jan 1, 2014

It has been common practice for many years to predict and control underwater blasting effects on the basis of certain simplified theories related to the pressures generated by underwater detonations. Unfortunately, two of the most commonly applied concepts in many instances do not provide an accurate modeling of typical field conditions nor the potential for damage. One of these concepts is that the damage potential is related directly to the peak pressure generated by an underwater detonation, without regard to the time history of the pressure pulse. This belief has led to the widespread use of air bubble curtains to reduce peak pressures, without considering the effect that air curtains have on the time history of the pressure pulse. At times, this procedure can be unwise. The other concept is based on the premise that pressure pulses in solids (such as rock) will always be transmitted to nearby water bodies in agreement with the theories of the transmission of plane waves across normal (perpendicular) boundaries. In reality, such conditions are quite rare.

Jan 1, 1985

By Lina Lopez, Jose Sanchidrian, Manuel Lopez, Pablo Segarra

Previous work in which rock properties and blasting parameters (geometry, charging and timing) were reported together with truck filling times, is taken as a starting point for a thorough analysis of the influence of the former on the mucking velocity. The experimental set was composed by 11 blasts made in an open pit mine. Non-parametric, distribution-free statistics is applied. The mucking rates (in bank cubic meters per unit of bucket volume and per hour) appear to be clearly dependent on the explosive energy and powder factor, both magnitudes combined as energetic powder factor (energy per unit of rock volume). The mucking rate is a non-monotonic function of such factor in the range of the blasts analyzed. The determination of the function is optimum when the fraction of the explosive below grade is not considered and when the explosive energy is qualified as that delivered at a partial detonation regime. Different types of loaders seem appropriate for different energy levels. At low levels both front loaders and rope shovels obtain small productivities without a statistically significant difference in their performance. At high energy levels, front loaders qualify higher than rope shovels. Mucking velocities can be equally small at low energy powder factors and at high ones if rope shovels are involved.

Jan 1, 2008

By W. J. Birch

The dedicated documenting of blast design and vibration monitoring results forms part of the best practice methodology for today’s blasting operators. This allows regression curves to be constantly updated and in turn compatible charge weight determinations are based upon the most current data. The point can arise however when so much data becomes agglomerated that variations in blast design, geology or monitoring location response and their effects can pass unobserved and start to have an adverse effect on the forecasting capability of the regression due to a deterioration of the standard error statistic. The simple solution would be to only compile like-for-like blasting returns, but this prospect can quickly become unworkable due to the number of potential variables. In addition it is very difficult to spot subtle variations by simply examining a standard scaled-distance curve mainly due to the intrinsic data scatter that is always present together with the logarithmic nature of the regression curve. If indeed a variation is thought to be apparent, how can the degree and magnitude of its influence to be quantified? The Likelihood Ratio Test when applied to regression data can diagnose subtle variations between data sub-sets and provides a comparative statistic as to the degree of variation. By analysing datasets in such a way, levels of compatibility are obtained, indicating which sets can be combined in order to increase prediction capability.

Jan 1, 2004

By Jerry W. Schweiker

An extensive computer program has been developed which will store and analyze pertinent blast related parameters such as date, time, shot coordinates, charge, delay times, etc. In conjunction with these blast parameters, measured ground vibration information can be stored. In addition to actual seismograph data, predicted ground vibration in terms of velocity (inches/sec) can be generated for selected receiver locations. The magnitude of the blast generated ground vibration is based on scale distance relationships. The program can be used for planning blasts, to satisfy local environmental regulations and for insurance and/or legal purposes.

Jan 1, 1984

By Robert Slivinski, Kyle Hobbs, Michael Stern, John Willox, Brad Jewson

Prairie Mines & Royalty Ltd. produces over 12 million tonnes annually of thermal coal for TransAlta’s Sundance and Keephills power stations from the Highvale Mine. This opencast mine is next to a lake and is surrounded by cottages and farms, which means that blast vibrations and air overpressure have to be kept to a minimum.

Jan 1, 2008

By Travis Davidsavor, Stanley: Dong Vitton

Concrete is a common construction material used throughout the world, and with increasing demand of fast-track construction, blasting and concrete casting are occurring simultaneously at many sites where rock is being excavated for concrete placement. However, there has been significant disagreement in the construction industry as to what intensity of shock vibrations green, or fresh concrete can tolerate. Peak particle velocities are often arbitrarily chosen, or are simply based on materials such as plaster and drywall that have been more thoroughly studied in relation to damage. Previous research on green concrete has used the concrete’s static strength subjected to shockwaves at different ages as the primary damage criteria. In addition, the static strength tests have been based on curing time. However, changes in temperature or humidity can dramatically alter the hydration rate, which affects strength development of different cements. To account for temperature changes and humidity the concept of concrete maturity is commonly used and allows the researcher to see where the concrete was in terms of hydration progress. In general, static testing determines the failure stress that the concrete’s macrostructure can handle, and often failure occurs in the natural materials first or along large defects in casting techniques. Dynamic testing or high strain rate testing, on the other hand, loads materials at such a high rate that larger defects do not have time to react and instead the microstructure is more highly stressed leading to higher strength and stiffness values. This is known as the material’s strain rate sensitivity. Since dynamic testing better tests the microstructural strength, it is believed that it may provide a better way to assess damage to green concrete. Testing includes both static and dynamic compression as well as static and dynamic splitting tensile strength to assess whether damaged has occurred to the concrete. No significant statistical evidence was discovered that damage to the concrete occurred at five different “green” maturities from peak resultant velocities ranging from 10.66 in/s (271mm/s) to 4.40 in/s (112 mm/s) with average intensity of 6.7 in/s (170mm/s).

Jan 1, 2003

By Donald J. Moore

It has become more important today than ever before to reduce costs and improve equipment utilization. One area where such improvement can he achieved is in the use of explosives. Effective blast design for efficient use of explosives as well as optimum fragmentation can achieve this. Towards this end we must have available to us a practical design method in which experience and observation can be translated to engineering concepts. We must he able to communicate the design data to field blasting personnel as well as management in an understandable way.

Jan 1, 1975

By Split Engineering Chile Fernando Fernandez

Mathematical modeling in conjunction with mineral characterization is widely used as a method for design and optimization of comminution circuits, to simulate the processes of crushing, grinding and classification. An important input parameter to the simulation models is the Run-of-Mine Particle Size Distribution (ROM PSD). The run-of-mine size distributions due to blasting have a great influence on the performance of a semi-autogenous grinding (SAG) mill. In this paper, a mine case study was conducted where there are four primary geologic units and the material properties between the four units vary considerably. Also, the mixture of the four unit that will be mined at any given time also vary considerably. This presents a challenge in terms of optimizing the blasting for mill production throughout the mine life. As part of the case study, field rock mass characterization, laboratory rock mechanics tests, and laboratory breakage tests were conducted. The field characterization and rock mechanics tests provide material properties used to simulate the effect of different blast designs on run of mine particle size distributions (ROM PSD). The JKSimBlast software was used for these simulations. The rock breakage tests provide material properties used to simulate crushing and grinding performance. The JKSimMet software was used for these simulations.

Jan 1, 2015

By David Kosnik

This paper describes the technology and methods deployed in the continuous autonomous remote monitoring of cracks in interior and exterior walls of a residence near a limestone quarry. The objective is to quantitatively compare crack response due to blast-induced ground motion to that induced by diurnal temperature changes, weather fronts, occupant activity, and other phenomena. The remote monitoring and communication technology developed to obtain and disseminate crack response data for this study may provide the means to mitigate the effect of public concerns about potential impacts of ground vibrations inherent in construction and production of raw materials; it is critical to address these concerns because subsequent litigation may result in delays and increased costs.

Jan 1, 2009

By Walter Jr Duke

The security of explosive materials is a vital concern to every mine, quarry and contractor engaged in blasting. Proper construction of magazines and sufficient locking mechanisms are the fundamental means of maintaining secure storage. The object of this paper is to review the proper methods of construction of storage facilities for explosives as defined by the Alcohol, Tobacco, and Firearms regulations. Subpart K subsection 55.208 and the Institute of Makers of Explosives recommendations.

Jan 1, 1991