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By Conny Sjoberg, Finn Ouchterlony, Bjorn Jonsson

This contribution reports an investigation of the blasting damage in the contour of an access ramp to a Swedish underground laboratory for nuclear waste related studies. Near zone vibration measurements were made for 7 rounds and the results converted to a site specific scaling law. A simple engineering correction for the influence of the charge length wee developed and the resulting equations used to predict the damage zone depths of three different drilling and charging patterns.

Jan 1, 1993

By Tyler Acorn, Tristan Worsey

A dozer operator at a surface gold mine accidentally drove a D10 off the side of a highwall. The blade of the dozer caught on the lip of a catch bench 60 ft. (18.3 m), down stopping its descent. The operator scrambled to safety in fear that the dozer would not hold.

Jan 1, 2014

By Regina Rocha, Miguel Humpire

One of the challenges within unitary mining operations is blasting, which has a significant downstream impact on the following processes, which is why mining companies ensure the results of the blasting process through joint work with explosives specialists’ companies.

Feb 6, 2023

By Randall M. Wheeler

Computer analyses of single hole signatures are often used to help blasting operators predict the type of ground vibration effects that may be produced from production blasts incorporating various delay intervals. Frequency analyses of single hole waveforms and subsequent multi-hole waveform simulations can allow an operator to determine the best type of delay intervals to use in order to minimize low frequency ground vibrations.

Jan 1, 1989

By Michael Burrell

This project involved the protection of an historic landfill located on the site. Construction blasting was for a permanent access road to carry traffic to and from a new metal processing plant being constructed nearby. The landfill contained materials disposed of during the closure of a Phosphorus plant that had previously occupied a portion of this site.

Jan 1, 2012

By Brian Lewis, Reinhold Daykin Schnell

Blasting specifications and guidelines are very important aspects of detailed project specifications covering any scope of work (SOW) that involves explosives and blasting procedures. A lot of larger construction or tunneling projects require some degree of project specifications for the entire scope of work on such project, including blasting specifications. It is important that all blasting specifications effectively and accurately address all explosives and blasting concerns associated with the SOW for such project. This includes safety and security, required personnel and their associated responsibilities, procedures and applications involving explosives, blast design and planning, blast monitoring and reporting, quality assurance and quality control, and local, state, and federal regulations and limitations. With the of wide range of information required in blasting and overall project specifications along with the risks associated with work involving explosives, it is also important to ensure qualified personnel are involved in interpreting or compiling and approving any blasting specifications and guidelines. The purpose of the following paper is to explore and present the basic information, as summarized above, that should be included and considered in the creation of detailed blasting specifications and guidelines. Detailed information is presented in specific relation to a potential bid package that would be compiled for a construction or tunneling project requiring protective or high-profile blasting.

Feb 6, 2023

By William Nicoll

Those who use electric detonators in firing blasts will be interested in a new electrical testing instrument known as the ‘Blasters’ Friend’, recently devised by the New York Blasting Supply Co. of New York. Owing to the necessarily delicate construction of the platinum wire bridge in the shell of a detonator, it frequently happens that it becomes broken or disconnected; thus destroying the circuit and rendering the detonator worthless. In many cases, misfires and premature explosions are caused by defective detonators. Heretofore, to detect the deficiencies of a detonator before using has been an impossibility, owing to the absence of a testing instrument adapted to the purpose.

Jan 1, 2010

By D. Swanson

Cold Detonation Physics (CDP) is a patented new field of explosives and the name for the explosive that is produced when non-toxic dry ice (frozen carbon dioxide) is combined with powdered metals such as magnesium and aluminum, which are non-toxic and nitrogen-free. The explosive is detonator-sensitive and detonates according to the rapid reduction of carbon dioxide back to carbon, which produces solids comprised mainly of metal oxides and about 5% carbon. CDP was determined to produce a maximum of 300 liters of carbon dioxide per kilogram (4.81 ft3 /lb) and about 1.5 liters of carbon monoxide per kilogram (0.024 ft3 /lb). Both these figures shift according to metal content where higher metal produces less gases. According to theoretical modelling, the relationship between static pressure and metal content was determined to be an inverse parabolic curve with optimum pressure at 25% to 31% metal, depending on the type/s of metal/s used. Velocity of Detonation (VOD) was determined by measuring light at the wavefront with fiber-optic cable inserted into a series of holes drilled into the side of a 3-inch diameter (76 mm) schedule 40 steel pipe containing the mixture. The highest VOD was observed at 25% magnesium and measured between 2,500 to 4,500 m/s (8202 to 14,764 ft/s) when initiated by a 454-gram (1-pound) booster and an electric detonator. A 25% 50:50 alloy of magnesium and aluminum sample shot at a higher velocity than magnesium, according to how the alloy generated smaller pieces of shrapnel when compared with shrapnel from a magnesium test. CDP, using 25% alloy, was tested for blasting limestone by drilling 3.5-inch holes (89 mm) and inserting a 3-inch x 4-foot cardboard tube (76 mm x 1.22 m) with the mixture, packed to a density of 0.62 g/cm3 . The blast was initiated with an electric detonator, behaved like ANFO with more energy and fractured rock sufficiently across the entire length of the borehole. Seismic analysis determined that CDP produces lower ground vibrations than traditional explosives.

Jan 1, 2024

By D T. Froedge

Before this study was started, literature was searched and cases of alleged water well damage were investigated. Occurrence of ground water in Appalachia is primarily in low yield, fractured, water table aquifers. Four test sites were chosen based on geographic and geologic diversity. Test wells were drilled at each site and base line data on water quality, static water level, and drawdown characteristics were obtained before surface mining commenced. Blast-induced ground vibrations were measured at the surface by the wells at levels up to 5.44 inches per second maximum resultant particle velocity. Measurements made at the bottom of wells indicated that vibrations were considerably attenuated at depths of 140 to 160 feet.

Jan 1, 1983

By B Kniivila, A B. Andrews, T Lerick, Keith Jansen

Minntac Mine is a large, open pit taconite mine located at the center of the Mesabi Iron Range in northern Minnesota. The planned development of the Mine in the direction of nearby communities prompted a comprehensive study of off-site blast effects that resulted in numerous refinements in blasting practices.

Jan 1, 1984

By Mick Fritz, Ryan Gilmore

The Center for Disease Control [CDC] is in the midst of a twenty year project, part of which includes demolishing existing buildings and erecting taller, more modern structures within the same foundation foot print. Controlled Blasting Inc, a large and experienced construction drilling and blasting company in Metro Atlanta, was contracted to provide the drilling and blasting for the new building foundations. Working on a construction site, in this type of environment, creates many challenges for the drilling and blasting crews.

Jan 1, 2008

By R. Alford

In the modern world of demolition safety is paramount and unnecessary or unquantifiable risks are not accepted (FasterCapital, 2024) and all risks must be kept As Low As Reasonably Practicable (ALARP) (BSI, 2017). This principle has led to a huge reduction in deaths in the last 50 years and the statistics continue to improve although this is starting to plateau (Beal, 2007). Under normal circumstances, this is now simply part of the normal way work is done and systems are in place to ensure both safety and economic profits are assured. What happens when the environment is less controlled and risks are unknown, such as after a natural disaster, war, an accident or a stand-up from a failed demolition attempt? A dangerous structure cannot responsibly be left alone with a fence around it so some action must be taken, but how can this be done safely and responsibly? An incident in Didcot, England in which half of a power station’s boiler house being prepared for an explosive demolition collapsed suddenly, killing four men in 2016 provides a useful case study of how technology, creativity and planning can be used to conduct complex demolition fully remotely to avoid any further risk to life.

Jan 21, 2025

By Keith Best

It has been said that when a person does something right no one remembers but when they do something wrong no one forgets. This statement, when applied to the explosives industry, has never been truer. Think about it.How many times have you seen a news crew reporting on how well a blaster is doing his/her job? Normally, all you will see is how bad things are going and how much “damage” is being done.

Jan 1, 2008

By Scott G. Giltner, Terry Millar, Ben Bringhurst

"Kennecott Utah Copper (KUC) Smelter scheduled a rebuild of their flash smelting furnace forSeptember, 2014. KUC’s goal in this project was to reduce the rebuild time from 65 to 55 days by using explosives to break the matte and brick layers of the uptake shaft and hearth sections of the furnace. Previous rebuilds had employed the slower technique of mechanical breakers to remove the matte and brick layers which took 22 days. KUC has many years of experience in removing slag from the uptake shaft, but they had never used explosives to remove the hearth. As far as KUC was aware, no other smelter operation had attempted a hearth removal in this way."

Jan 1, 2016

By Robert Hopler

THE work that is being done by the Government to reduce the dangers of mining was brought out strikingly in the First National Mine-Safety Demonstration which occurred at Pittsburgh, Pa., on October 30th and 31st, under the auspices of the United States Bureau of Mines with the assistance of the American National Red Cross Society and the Pittsburgh Coal Operators’ Association.

Jan 1, 2012

By Lon Santis, Michael Swisdak, David Leidel, John Tatom

The Institute of Makers of Explosives (IME) and A-P-T Research, Inc (APT) have developed and released a quantitative risk management tool, IMESAFR (IME Safety Analysis For Risk), for the commercial explosives industry. Consequence algorithms in IMESAFR are considered state-of-the-art. Generally, they mirror those in SAFER (US Department of Defense Explosives Safety Board quantitative risk management software). The science behind the software has now been assessed for its maturity. Results have identified areas where additional test consequence data could improve predictions. To address these areas, full-scale testing programs to provide the needed data have been formulated. Proposed testing efforts include work to: (1) improve characterization of explosive articles now absent from SAFER, and (2) refine modeling of the Potential Explosion Site (PES) types, particularly small metal structures, also not found in SAFER. Goals of each program as well as requirements for conducting the tests have been established. Testing results are to be used to improve the algorithms and to further the state-of-the-art in risk-based explosives safety.

Jan 1, 2012

By Scott Stephenson

Making a tunnel through solid rock can sometimes be a dangerous task. Many things must be considered in order to complete such a task safely, and efficiently. Prior to starting things must be known such as, the type of rock, the purpose for the tunnel, the destination point, then angle of decent (or ascent). Once these things are known, the method to proceed must be considered. Factors such as cost, feasibility, and time to completion must be taken into account.

Jan 1, 2009

By Don Larson, Gordon Coleman

The United States Department of Energy, through its contractor Lawrence Livermore National Laboratory, has entered into a contract with Alpha-IRECO, Inc. for the emplacement of approximately 2.9 million pounds of a 50% RX-MD emulsion 50% ANFO blend into an underground chamber for initiation to produce the 12 trillion caloric equivalent of 1,000 metric tons of TNT. The detonation will be closely monitored to determine the characteristics of a large chemical explosion for comparison with data collected from previous like-sized nuclear events in the same location. This data will be shared with former Soviet block countries to facilitate enforcement of the various non-proliferation treaties currently being negotiated between the countries.

Jan 1, 1994

By Manuel Calderón

Chile is responsible for 30% of the global copper production; the world ́s largest. However, significant challenges are faced in this industry; declining grades (1.13% in 2002 to 0.61% in 2015), high cost of energy, scarcity of water, and environmental concerns. Mining trends suggest the future of the industry will be focused in the underground space, specifically due to the depletion of economically viable surface mineral deposits. For example, the largest block cave mineat Codelco ́s Chuquicamata mine is expected to reduce energy costs by 50% and dust emissions by 97%compared to the open cut mine. To access these underground deposits, critical infrastructure is required; horizontal tunnel developments, extraction levels, vertical raises, and ore passes with the on-time delivery of the highest quality outcomes being a requisite for successful project delivery (Lift 1 of 3 at Chuquicamata Underground has over 1000drawbells).One aspect that makes this scenario even more challenging for deeper underground operations is the increased risk profile (people, equipment, and geotechnical) that forms part of the general environment. Furthermore geotechnical risks should be considered and they include rock burst and windblast. The safe interaction with this environment must be sustainable throughout the full life of the project. This paper presents the Enaex group approach to addressing the blasting challenges and outlines the solutions created. Aspects such as rock mass damage occurrence as a function of blast vibration frequency content has been studied, as well as the development of blasting methodologies for guaranteeing the full 100% extraction of all infrastructure blasts, including the all-important draw bell volumes. The development of such infrastructure volumes in one single event using electronic detonators and the associated achievement of ambitious productivity goals, are described as a critical part of the successful construction of one of the most ambitious UG projects currently present on the world.

By Damien Bretall, William Fourney

Due to the changing face of warfare there is an ever growing need to protect the underside of combat vehicles from mine blasts. This paper presents a new method to better characterize the pressure profiles experienced by a plate as the blast develops. The explosive deformation of a small-scale plate was recorded using synchronized high-speed digital cameras, and then analyzed using 3D Digital Image Correlation software. Time-varying pressure profiles were input into an axisymmetric FEM simulation by fitting curves to data obtained from tests using Kolsky bars to measure pressures. These were then modified to find possible profiles that produce the measured deformations. It was discovered that the final deformation cannot be determined from only total impulse or peak pressures, and that it is very sensitive to the time and spatial decay of the pressures.

Jan 1, 2009