Search Documents

By John Dean Smith

In order to discuss problem solving techniques for the future. we must first review the past. This paper will discuss the drilling and blasting problems and techniques that were used by .Imax Coal in the past few years, tn those of today.

Jan 1, 1991

By Tristan Worsey

This work was performed during the summer of 2008 during the junior year of a BS in Mining Engineering. It was observed that the mine was having a problem with back break during the blasting of development drifts. The unwanted back break was causing the mine extra costs in ventilation, ore dilution, ground support, back fill, explosives and man-hours. The blasting practices were observed for four weeks and the problems and their solutions were defined. In this paper the reasons and causes of the problem are explained with the proposed solutions to eliminate back break.

Jan 1, 2010

By Inc. The HDH Group

The Alternative Risk Market is defined as the segment of the insurance market that is made up of self insurance, risk purchasing groups, risk retention groups and captives. It is commonly referred to as the alternative to the traditional market, even though more the majority of companies today are insured through the alternative risk market than the traditional market.

Jan 1, 2007

By Barend Botha, Trevor Davids

The presence of an extensive soft siltstone layer in the middle of the inter-burden sequence of rocks at Syferfontein Colliery in the Republic of South Africa prompted tests to determine the effect of different mid-column decks of inert material in the siltstone layer. The objective was to achieve significant cost savings in explosives use whilst not degrading dragline productivity. An important factor that had to be considered was that the initiation systems available in South Africa are not accurate enough to ensure simultaneous initiation of explosives decks in a blasthole. A number of inert materials were tested including ash, drill cuttings, river sand and crushed stone. It was found that the ash, drill cuttings and river sand did not effectively attenuate the shock wave and that the risks of sympathetic detonation or partial disruption of one or the other explosives deck in a blasthole was high. This became much worse when the inert material was saturated with water. Crushed rock was the most effective in attenuating the shock wave, but this material was very expensive to use because it had to be imported onto the mine.

Jan 1, 2000

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 Charles O'Connor, Ben Tisa

International Training Resources is a company consisting of personnel with extensive law enforcement and military special operations experience, The staff members are qualified to train and certify, assist and advise law enforcement officers and agencies, at any level, in critical incident policy, procedures and tactical resolutions. Successful critical incident resolution is comprised of many elements of professional skills and personnel. (Command staff, negotiators, snipers, tactical teams, uniform patrol, K-9, bomb squad, etc.) Recently, tactical teams have been developing the capability for the use of explosive methods for rapid entry into crisis locations. This document ‘will briefly describe the environment, operational issues and courses of action associated with developing a complete tactical breaching program for utilization by SWAT teams in response to operational conditions in critical incident situations. This topic is being presented to the I.S.E.E. evaluators under “Interesting Blasting Projects” and “Public Relations” categories. Tactical operations differ significantly from traditional industry practices and we appreciate the opportunity to show the industry other professional applications of explosive materials and techniques. Presently, of the few schools from which law enforcement officers can receive training with explosive breaching methods, International Training Resources is the only company currently teaching and certifying officers which has received total endorsement by the California Peace Officer’s Standards and Training Commission (P.O.S.T.) and the state blaster’s licensing commission. We have pioneered the combining of law enforcement needs and blasting industry technology to train tactical officers, nationwide, in the mission essential skills necessary for explosive breaching.

Jan 1, 2000

By Karl E. Burgher

Since World War II, the need for the use of explosives with testing, construction, demolition, mining and quarrying near urban areas has increased dramatically. Once remote, testing areas have been encroached upon by commercial and residential areas. Evidence has been found that overpressure levels near these areas can be estimated using meteorological conditions. This paper reviews a study where 205 test shots were fired, meteorological conditions recorded, and over-pressure levels estimated using multiple regression techniques.

Jan 1, 1988

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 Marcia Harris, Richard Mainiero, Michael Sapko

Since 1988, there have been 17 documented incidents in the United States and Canada in which carbon monoxide (CO) is suspected to have migrated through ground strata into occupied enclosed spaces as a result of proximate trench blasting or surface mine blasting. These incidents resulted in 39 suspected or medically verified carbon monoxide poisonings and one fatality. To better understand the factors contributing to this hazard, the National Institute for Occupational Safety and Health (NIOSH) carried out studies in a 12-foot diameter sphere to identify key factors that may enhance the levels of CO associated with the detonation of several commercial trenching explosives. The gaseous detonation products from emulsions, a watergel, and ANFO blasting agents as well as gelatin dynamite, TNT, and Pentolite boosters were measured in an argon atmosphere and compared with those for the same explosives detonated in air. Test variables included explosive formulation, wrapper, aluminum addition, oxygen balance, and density. Major contributing factors to CO production, under these laboratory test conditions, are presented. The main finding is the high CO production associated with the lack of afterburning in an oxygen poor atmosphere. Fumes measurements are compared with the manufacturer’s reported IME fume class and with the Federal Relative Toxicity Standard 30 CFR Part 15 in order to gain an understanding of the relative toxicity of some explosives used in trench blasting.

Jan 1, 2003

By Weiying Zeng, Shouwei Wang, Jinbei Zhong, Xiangdong Meng, Lingtian Meng

"Due to a drainage problem, the Lanzhou to Chongqing high-speed rail line had been out of service during the 2015 wet season, so a drainage tunnel is to be constructed for the line and required to be accomplished before the 2016 wet season. This drainage tunnel is only 5 meters below the line which is in service, therefore blasting vibration needs to be strictly controlled. This paper introduces all theapplied blasting methods, parameters and detonation throughout the entire project, finally bringing in the electronic detonator stagger phase technique and corresponding time difference for detonation."

Jan 1, 2017

By Ruilin Yan, Kameron Ray

This paper reports a simple approach to model the waveform change due to travel distances based on the field measurement. A linear interpolation is used to estimate the waveform at a distance from two vibration waveforms recorded at two different distances. The resulted waveforms are compared with actual recorded waveforms at the point in both time and frequency domains. It shows that the proposed method to estimate the waveform change yield reliable results. The advantages of the proposed method are that it does not require assumptions that a transfer function does and that it is based on purely the measured waveforms that are encoded with in-situ rock properties. The method could be more reliable for far field seismic waveforms and could be an approximation for near field waveform estimation.

Jan 1, 2014

By O. Cermak, F. Degonld

Although 3D fragmentation analysis is a relatively new technology, it is rapidly gaining popularity among mid-sized mining operations and quarries. The results provided by this technology are adequate, but like other picture analytic methods, it mainly focuses on the surface of the muck-pile. These results are incomplete or incorrect as falling rocks and boulders from the stemming zone are constantly influencing the muck-pile surface. This obstacle can be overcome by collecting a large amount of data and analyzing it over time. However, this is not always an ideal solution, as companies prefer to receive results immediately after the blast to make resource allocation decisions, production planning, and plan for the next blast. Over the past year and a half, we have conducted a study on various muck-pile fragmentation analysis results from 3D modeling in Central Europe, comparing the results between the surface and inside of the muck-pile. By analyzing multiple shot results, we were able to determine the percentage difference between the top and inside fragment sizes and calculate the range of correction coefficients for different rock types. Applying these coefficients to a single muck-pile surface fragmentation analysis allows us to determine the actual fragment sizes inside the muck-pile. This enables us to make informed decisions regarding loading, hauling, material mixing, and proper crushing or milling. By overcoming the limitation of surface-based analysis, we can now accurately evaluate blast performance, which leads to better processes optimization and increase efficiency. As 3D fragmentation analysis becomes more widespread, we expect to see even more benefits for the mining and quarrying industry

Jan 1, 2024

By Marcus Neves, Eventomar Junior, Adilson Castro, Leandro Silveira, Sérgio Augusto

The collapse of the Vale S.A. mining tailings dam in 2019, a tragic event that shook Brazil and the world, had consequences that transcended the immediate pain and devastation. Among them, the suspension of rock blasting activities in several mines in the Quadrilátero Ferrífero region of Minas Gerais, Brazil. This measure, taken as a precaution and with the aim of ensuring the safety of nearby geotechnical structures and the population, had a significant impact on the mining production chain. To overcome these challenges and resume blasting activities in a safe and sustainable manner, the mining industry has been dedicated to developing and improving solutions. One of the promising alternatives is the signature hole technique, used in conjunction with attenuation laws. The complex geology of the Quadrilátero Ferrífero, with lenses of compact ores immersed in friable materials, the presence of discontinuity families, and the emergence of geological faults, requires detailed analyses and specific adaptations of the signature hole technique and constant monitoring of the vibrations to calibrate the attenuation laws to ensure compliance with permissible limits and safety of the operations. To demonstrate the methodology, a case study in Abóboras Mine was described. Additionally, the challenge of achieving the desired level of production while controlling vibration and slope damage has driven the development of new charging and timing techniques. To address this challenge, a comprehensive approach was undertaken. A substantial database containing more than 4,000 registers of blasting-induced vibration events from 520 blasts was meticulously compiled from 2020 to 2023, 6 different attenuation laws were established and continuously calibrated with 99.3% of compliance regarding permissible limits of vibrations. The successful implementation of these actions allowed for the resumption of blasting, increasing production from 10 million metric tons to 43 million metric tons per year assuring sustainable operation.

Jan 21, 2025

By Rolf Schillinger

Blasting activities on the surface or underground necessarily involve the most sensitive aspect of environment remediation, human response or annoyance. Such effects are unavoidably characteristic of those activities. For this reason, blasting activities are governed by law and official regulations under surveillance of authorities, where companies and explosives engineers have to proceed within proper limits. Subject of the paper is a practical way of handling some necessary vibration standards being focused on blasting activities. The paper is based on the German Standard DIN 4150, Part 1 - 3, “Vibration in buildings”, Part 1: “Prediction of vibration parameters”, June 2001, Part 2: “Effects on persons in buildings”, June 1999 and Part 3: “Effects on structures”, February 1999.

Jan 1, 2006

By Anderson Meireles, Leonardo Soares Chaves, Raul Carretero Hoz, Carlos Eduardo Soares Feliciano, Renato Jacome Costa

The large iron deposits in the northern region of Brazil located in the Amazon Craton have in common the presence of natural cavities. These cavities primarily occur in the upper layer of the ore body, formed above hematite mineralization. Their origin remains a topic of debate, often associated with hydrothermal drainage processes and erosive evolution. Over time, these cavities have become integral to the local environment, each contributing to the regional ecosystem of fauna, flora, and the significance of speleothems found within them. Managing these cavities poses a significant challenge for iron mines in the area. On one hand, they must preserve the cavities from anthropogenic actions, while simultaneously handling heavy equipment and large volumes. In 2023, the development of the mine took place towards the cavity under study, revealing systematic deviations in vibrations recorded during nearby detonations as the blasting got nearer. To address this, a work plan was put in place, emphasizing a straightforward approach: constructing lithology-specific vibration models, defining charge abacuses, and optimizing timing to reduce charge amplification. Implementing this methodology significantly improved adherence to the vibration limit, resulting in an around 50% reduction in standard error. This paper presents the consolidated work that allowed mining activities to continue in the area through controlled blasting, effectively mitigating potential anthropogenic damage in sensitive areas.

Jan 21, 2025

By Gregory L. Hempen

"Pressure waves from submerged blasting can have adverse impacts on nearby structuresand on aquatic fauna. Underwater blasting is not allowed for some situations withoutmitigation of these adverse pressures. Two states currently require bubble-curtain, pressurereduction of underwater shooting for environmental concerns. St. Louis District hasconducted field monitoring of scaled testing and demolition shooting with air-screenmitigation. The deployment of compressed-air manifolds and air-entrained packagesheeting effectively reduces underwater blast pressure. St. Louis District is preparing areport on optimum use of underwater-blasting mitigation measures."

Jan 1, 1993

By Dennys Huaman, Carlos Rojas

Using the Levenberg-Marquardt algorithm to reparametrize the Kuz-Ram original model equation of the mean characteristic size and assess the errors of both models and their comparisson using different statistics measures like chi-squared or relative error with the usage of the Monte-Carlo algorithm.

Feb 1, 2020

By C Agreda

The Cushion Blasting Technique applied to solve the high risk case history represented by a 10,704 TM rock locate at 120 M from the hydroelectrical plants of 350 KV each, is described, analyzed and discussed. The generation and distribution of 700 KV produced by two hydroelectrical plants must not be interrupted by any reason, because the 26 district of the province of cajatambo, of the Lima department; would not have electrical power. The search of the best alternative and methodology, the drilling and blasting pattern calculations, charge design and loading, connections and initiations of the 50 blasts are described, analyzed and discussed. Finally, the excellent results from a technical, economical, enviromental and safety point of view of the 50 primary blasts are discussed and emphasized.

Jan 1, 2005

By Alastair Torrance, George Boucher, Roger Keller

An investigative blast programme has been carried out to provide information on the best blasting methods to excavate Chek Lap Kok island in Hong Kong for the new airport. The objectives of the programme included the assessment of a range of blast design parameters and their influence on fragmentation. This has been evaluated by physical assessment, photo digitising of the muckpile and computer predictions. In addition, a model to predict the three dimensional muckpile shape has been successfully calibrated.

Jan 1, 1992

By Deepesh Yadav, B. S. Choudhary

Underwater drilling and blasting is conducted for deepening of sea channels for port berths, lake or reservoirs for water supply etc. so that rock dredging becomes easier. During this process there are several associated unwanted effects having potential to cause damage to surrounding structures and the environment, flora and fauna. Though all these ill effects can’t be completely eliminated but adopting controlled blasting techniques can minimize these to tolerable levels. It is recognized that ground vibrations resulting from rock blasting below water near dam may endanger the safety of earthen dams. Therefore, controlled blasting technique was used to ensure the safety of dam and its efficacy was established by monitoring of blast vibrations. The usage of small quantity of explosives confined in blast holes, non-electrical delay detonators and initiating each hole with a separate delay helped to minimize the ground vibration effects on surrounding structures.

Jan 1, 2018