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By Mike McGill, Stephen Chung, Dale S. Preece

Cast blasting can be designed to utilize explosive energy effectively and economically for coal mining operations to remove overburden material. The more overburden removed by explosives, the less blasted material there is left to be transported with mechanical equipment, such as draglines and trucks. In order to optimize the percentage of rock that is cast, a higher powder factor than normal is required plus an initiation technique designed to produce a much greater degree of horizontal muck movement. This is a significant change from normal blasting practice where fine fragmentation and sufficient muck movement were the prime requirements to permit efficient excavation.

Jan 1, 1994

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 Shijie Qu, Paul N. Worsey

Pre-splitting has become widely adopted for the formation and protection of final surface rock excavation profiles in both large scale civil construction and highway rock cuts. Jointing has been shown to affect the success of pre-splitting and the smoothness of the resulting profile, however, only closed joints have been investigated. Frequently jointing that is closed at depth is open at and near the surface due to weathering, reduced stresses and ground water percolation. In many instances, problems are associated with surface rock layers whereas at depth these problems are either reduced or do not exist.

Jan 1, 1987

By S Burchell

During the past few years, high-speed cameras, laser surveying equipment and photogrammetry have become standard tools for recording blast geometry and results. While laser profiling yields accurate 3-D measurements, most cameras capture only two-dimensional images. Attempts to extract 3-D information from photographs have been unsatisfactory. Recent advances in electronic imaging and computer programming have made it possible to develop a 3-D computer based analysis system which can capture and measure 3-D images quickly and accurately. This paper describes the technology to create 3-D images and to analyze blast geometry before, during and after the blast.

Jan 1, 1992

By Donald H. Matthews

The Society of Explosives Engineers is an international organization of over four hundred members involved in the explosives industry, with most members being active in the United States. The regulations imposed by regulatory agencies on the explosives industry have drastic effects far beyond the industry. Since explosives are used in mining, manufacturing, construction, entertainment, and art, all phases of man's activities, including fundamental needs for survival, are affected by how efficient the industry uses explosives. We, as members of SEE, must be sincerely concerned with both the quantity and quality of government regulation, and this paper spells out some of the problems caused by regulations and offers a solution.

Jan 1, 1980

By Thomas M. Keevin, Gregory L. Hempen

Natural resource agencies, under various regulatory authorities, are challenged with permitting underwater explosive use while at the same time protecting aquatic resources. Deciding on whether or not to allow use of explosives requires striking a balance between development and aquatic resource protection. A company's goal in underwater explosive use is to select methods that are both expedient and cost effective. Use of explosives is often the best alternative for engineering reasons or economic considerations. Over and above legal requirements, indiscriminate destruction of fish and other aquatic resources is not in a company's best interests because of concerns relating to public image, as well as the need to secure future contracts.

Jan 1, 1995

By Lewis L. Oriard

Some two million cubic yards of sandstone and orthoquartzite were blasted and excavated at Upper Stillwater Dam, located high in the Uinta Mountains in northern Utah. The material was processed to produce concrete aggregate for the construction of the largest roller compacted concrete (RCC) dam ever constructed, and one of just a few in existence. The dam cross-section is shown in Figure 1. The aggregate was sound rock produced from required dam foundation excavation and from a quarry located about 1/2 mile from the dam site. Representative compressive strengths of the sandstones and quartzites were in the range of 20,000 to 30,000 psi.

Jan 1, 1993

By S. Nakamura, H. Taniguchi, K. Noguchi, H. Sugihara, T. Matsuzawa

It has been reported that expanded poIystyrene and ANFO prills ‘were mixed on a blasting site for controlled blasting (ISANOL). Although there seems to be few possibility of their segregation because mixing on a blasting site is done, there is a great possibility of segregation in packing, transportation and loading of the product due to the different densities of the two ingredients in Japan where mixing on a blasting site still remains inoperative. The fiee-flowing property of ANFO prills was lost with the passage of time because the Abel oil infiltrated into the expanded polystyrene and that gave the product high viscosity.

Jan 1, 2001

By Pierre Auger, Benoit Levesque, Richard Martel, Guy Sanfacon, Louis-Charles Boutin, Marc-Andre Lavigne, Patrick Brousseau, Luc Trepanier, Louise Galarneau

Explosives used for blasting operations in civil engineering works, like construction of piping systems under roads, of pools, of houses and buildings can generate large volumes of carbon monoxide (CO). Carbon monoxide can represent between 1 to 3% of the gases produced by usual explosives. The production of 10 to 24 1 of CO by kg of explosives blasted is theoretically anticipated. CO is a gas that has no characteristic colour, smell or taste. It can migrate in the fractured rock of the blasted areas on fair distances, and then infiltrate in closed spaces like sewage systems, manholes, but also in basements of houses. In Quebec, in the last 10 years, 7 people were poisoned by CO in their houses to the point that they had to be treated in hyperbaric chambers. In the USA, many accidents have occurred and one worker died in a manhole. From the review of intoxication cases, the distance of migration of CO may reach 55 m if a conduit is present underground. Underground conduits broken by blast, tilling around underground conduits in road or house trenches, or fractured rock created by blasts between houses or between a house and a road, are the different pathways identified in the Quebec incidents. Field tests were performed at sites close to CO intoxication locations in order to evaluate the behaviour of CO in fractured rock following blasting operations. From these tests, the following conclusions may be drawn. The structural geology of the rock formation (schistosity, family of joints, fractures) plays a role in the direction and extent of gas migration in fractures generated when rock is blasted with explosives. The confinement of the rock can affect the quantity of gas migrating in the fractured rock. Significant concentrations of CO may persist in the fractured rock even 7 days after a blast. Advection is the initial mechanism of CO migration in fractured rock generated by the blasts or naturally occurring before the blast. The distance of migration with this mechanism is short (5 to 8 m). In trenches of muck (equivalent to tills under roads) the distance of CO migration by advection is 12 to 20 m. In the 2 to 3 days following the blasts, further CO migration up to 15 m is made by diffusion in the induced fractures, or up to 30 m in the trenches. To minimise CO production and migration in the fractured rock during blasting, special procedures can be applied by the blasting contractors: (1) do the complete excavation of the overburden before drilling and put mats for each blast; (2) do the complete excavation of the muck after each blast; (3) the last blasting should be the one for the private services entrance of the house and the excavation of the muck should begin at the junction between the road trench and the services entrance trench. Another technique consists in the pumping of interstitial air in the muck with a vacuum truck immediately after each blast.

Jan 1, 2002

By Thomas P. Dowling

Historically, laws controlling the manufacture, sale, transportation and storage of high explosives and regulations governing the use of explosives were formulated to prevent accidents or eliminate incidents that might jeopardize public safety. Many of the original laws and regulations regarding classification of explosives and blasting materials, tables of distances for separation and/or isolation of explosives, construction of storage magazines and methods of blasting were based upon empirical data, field experiments or scientific facts. During the past few years, however, it appears that some of the explosive laws and blasting regulations introduced and/or enacted by federal, state and local agencies seem to be based more on political expediency than on factual information or technical data.

Jan 1, 1976

By Charles B. Ingram, Neil E. Gehrig

The development of water gel explosive products has been the single most important development in explosive research and development since the invention of nitroglycerine and dyne-mite many years ago. m e Explosives Department of Gulf Oil Chemicals Company has been engaged in the research, development, manufacturing an marketing of slurry explosives and blasting materials for over twenty years. Explosive research and development is being carried out at the Jayhawk Technical Laboratory and the Underwater Testing Facility near Pittsburg, Kansas. There are fourteen manufacturing facilities geographically located around the country to serve the mining, quarrying, and construction industries with a complete line of explosives, blasting agents, and accessories. This paper discusses the Gulf slurry products, their properties, and uses.

Jan 1, 1977

By Dale S. Preece, Stephen H. Chung

"In bench blasting, the distribution of loaded explosives with respect to the burden rock has strong effects on digging especially at the toe area. Blast design often focuses on other results such as percent-cast or fragmentation, sometimes leaving a diggability problem at the toe of the blast that is not discovered until excavation. A method for assessing the influence of blast design on diggability has been developed. This method relates the kinetic energy and rock displacement experienced by the material in the muckpile to its diggability. Simulation of the blast along with the calculation of kinetic energy and diggability is done with the discrete element computer program DMC_BLAST(DMC: Distinct Motion Code)."

Jan 1, 1999

By Rob Farnfield, Mike Kelly, Toby White

There are a variety of sources of dynamic stress which can affect a building and give rise to cracking. A two-storey house, situated in the middle of a surface coal mine was monitored for a period of 30 months to attempt to identify the major causes of cracking. The factors described as environmental include internal and external temperature, humidity, wind speed and direction, rainfall and water table level. These were monitored using a weather station and piezometer and recorded every 20 minutes. The other factors are vibratory and include normal household movement (walking, shutting doors etc.), vehicle vibration and blast vibration. All the significant vibrations in the house were recorded using four sets of velocity transducers and accelerometers.

Jan 1, 1993

By Kahmmelly Mathildes Pimenta Coelho, Felipe Dantas, Jaine Ribeiro de Souza, Augusto Ferraz, Carlos Roberto Campos Junior, Davi Bastos Martins de Oliveira

The Carajás Iron Mine, recognized as the largest iron ore province in the world, is notable for its continuous efforts to improve operational efficiency and safety. In response to these objectives, a QA/QC (Quality Assurance and Quality Control) Program was implemented and integrated with Blastscout Probe technology to optimize drilling and blasting processes. The program supports the standardization of operational parameters, the execution of regular audits, and real-time data analysis, facilitating precise and timely adjustments. The implementation led to significant improvements, including an 80% increase in operational compliance, a 49% reduction in drilling depth deviations, and a 30% enhancement in Jaspelite fragmentation. This study presents the methodology employed, the outcomes obtained, and the positive impacts observed in both operational performance and environmental management.

Jan 26, 2026

By Paul Ross, Harry Burchett, Lou Case, Calvin J. Konya

"The Cumberland River in Harlan, Kentucky has flooded the town for numerous years. TheU.S. Army Corps of Engineers funded a project to divert the river. The project consisted oftunneling through a mountain to divert the river. The approaches to the tunnels requiredcontrolled blasting to create noses to help channel the water and debris into the tunnels.The geologic structure was such that conventional presplitting techniques were notproducing the desired results and were causing severe backbreak. Replacement of the rocknoses with concrete would cost about a million dollars; and therefore it was important tosave them if at all possible. Blasting techniques were developed which allowed the projectto be successfully completed. This paper will discuss the case history of the controlledblasting procedures."

Jan 1, 1993

By S. J. Dillingham

One of the primary goals of every blaster is to achieve the optimum blast design. Too much focus on efficient design, however, can cloud certain issues and exposures that must be addressed if the entire project is to be considered .successful.. Due to the known human response to blast effects and inherent dangers present in the use of explosives, the potential for the project being delayed or shutdown, or the blaster and associated company being named as a defendant in a lawsuit, is always a possibility. Therefore, the blast design and associated project bid must incorporate sound safety contingences and procedures that address those .what-if. Scenarios that may arise as a result of vibration, flyrock, public relations, and job-site personal safety.

Jan 1, 2002

This paper presents a brief discussion of three case histories to illustrate several aspects of the question of blasting in or immediately adjacent to concrete. The results demonstrate a need to make dramatic upward revisions in previous criteria, whether it be the standard particle velocity criteria or damage response spectra bounds, - especially those which include conservative upper limits of constant acceleration for the high-frequency portion of the spectrum. It is demonstrated, also, that conventional off-the-shelf blast-monitoring instruments are not capable of monitoring small blasts at close range. Both the frequencies and the levels of effect are beyond the range of such instruments. These case histories suggest further that there is a need to review the applicability of certain wellknown equations of elasticity.

Jan 1, 1980

By Harry Verakis, Thomas Lobb

A great deal of information has been presented and published on the danger from flyrock created from blasting operations. The creation of flyrock is not specific to any one blasting operation. Flyrock is certainly not a stranger to blasting operations conducted in the mining industry and its effects are well known. Flyrock is among the leading causes of mine blasting injuries. Awareness and diligence is the message that must continue to be stressed and followed to reduce the potential for creating flyrock from blasting operations and to reduce the hazard it presents. A recent accident that resulted in a serious injury at a limestone mine in Pennsylvania bears witness to the ever-present danger of flyrock created from blasting operations.

Jan 1, 2007

By Michael E. Kovach

This discussion is an overview of an approach to drilling and blasting angle holes at Martin Marietta Aggregates. Method of determining burdens, hole depths, angle settings and explosive selection will be discussed in detail with an emphasis on safety and production. Such techniques and methods involve the use of hand-held surveying instruments such as the Abney level, pocket transit and inclinometer along with measuring tape and burden pole. An interesting method developed by Oscar Banfield a retired Martin Marietta and E. I. duPont engineer, for setting the proper angle on a drill will also be presented. This treatise is a discussion of the use of simple yet important tools and techniques a blaster should use to resolve both routine and complex problems encountered during quarry blasting operations.

Jan 1, 1992

By Qi Jingyue, Wang Zhongquian, Yang Nianhua

Qinling Tunnel is the longest tunnel in China. The rock stratum is very hard rock - intact mixed gneiss. At the beginning of the construction, drift-pilot excavation is very costly due to the use of regular drill and blasting methods. After tests on the acoustic impedance match between rock and explosive, watergel explosive, which has a high velocity of detonation and high brisance, has been used for hard rock blasting. In addition, different cut plans have been compared. It was found that four-large-hole cut is the most effective. And the number of drillholes and specific charge cut down and the average advance reaches more than 94% of the blastholes depth. Thus, the difficult problem of hard rock blasting in drift pilot is successfully solved, while safe and quick construction is guaranteed.

Jan 1, 1998