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By Larry Schneider

Are you one of the thousands of hunters, fisherman, or hikers who purchased handheld GPS systems over the past several years and then been disappointed in their accuracy and performance. Or maybe you are one of the hundreds of blasters who have attempted to use GPS as a method for locating the exact position of their blast and measure distances from the blast to nearby structures. If so, you may have found that the accuracy of the handheld GPS systems left much to be desired. It may be time to get the units back out of storage and give them another try. As of midnight, May 1, 2000, the federal government has turned off the “error” built into the system known as “selective availability.” Here is a brief explanation of what that means in a question and answer format.

Jan 1, 2001

By C. Sawmliana, P. Pal Roy

Near-field blast vibration response of restrained pipelines either buried or exposed was studied during rock excavations at sensitive locations for Stage-II (4x500 MW) commissioning work in a super thermal powerplant of the National Thermal Power Corporation Ltd. (NTPC) of India. The existing running plant of capacity 1000 MW has many important installations including pipelines of varying diameters. These pipelines were very close to the blasting locations (mostly within 12m). Blast optimization and consequent monitoring of vibrations were carried out simultaneously for more than 250 experimental blasts conducted by the authors. This paper emphasized, particularly, on the safety of pipelines and their responses due to repeated blasting impacts. A few guidelines supported by theoretical derivations are provided for futuristic research.

Jan 1, 2001

By Raymond Chenier

British Columbia (BC) is Canada’s most western province. The landscape in BC is amongst the most beautiful and pristine in the world. Along with its beauty come vast mountain ranges, coastal rain forests, swamplands, deep river valleys, and almost every type of landscape imaginable. These all have, or at one time had, logging roads constructed. Some of these areas should never have had roads constructed due to poor drainage and unstable slopes, but some of the roads could be considered engineering masterpieces. To navigate a vehicle the size of an off-road logging truck down the side of a mountain with an 80°h side slope or greater can be a hair-raising experience. Not to mention coastal rains and/or high elevation blizzards. These factors collectively make logging BC’s most hazardous occupation. People are seriously hurt, sometimes even killed everyday.

Jan 1, 2001

By Jean-Sébastien Lambert, Joseph Kabuya, Richard Simon

Managing a highwall failure risk in an open pit mine by controlling and mitigating the impact of vibrations produced by blasting operations is key to achieving safe and cost-effective operations. The impetus behind this study was the risk of multiple bench failures in an open pit mine that was detected by Slope Stability Radar (SSR) following blasting at the foot of a highwall. The unstable high wall was over 140 meters(459.3 ft)high and 200 meters(656.2 ft)wide. The quantity of associated material was estimated at 3,000,000 metric tons(3,306,934 US tons). The overall slope angle was 44 degrees. In order to continue mining without causing the highwall to fail, this study was initiated as part of a risk management plan to mitigate this major risk by identifying mitigation measures related to blasting operations and assessing the response of the rock mass to each blast. Identifying blasting mitigation measures consisted of optimizing blasting parameters to avoid failure of the highwall. First, a signature hole operation was carried out to obtain seismic records that were georeferenced and associated with known single charges. The method used made it possible to determine the propagation velocity of the P-waves associated with the various lithologies studied and to calculate, from the geomechanical properties of the rock masses, the maximum peak particle velocities to be respected. Subsequently, the targeted area of operation was modelled with the I-Blast software in order to optimize the firing sequences to be used according to the different lithologies present. The model also made it possible to optimally predict the particle velocities associated with each blast and ensure compliance with the previously determined peak particle velocity limits. The assessment of the rock mass’s response using SSR consisted of defining alarm thresholds and an intervention plan for various possible alarms as well as quantifying the damage to the highwall from blasting. Controlling the impact of blast vibrations on the highwall’s stability was successful, as the mitigation measures used during mining did not accelerate the highwall’s movement. No upward trend in the stabilization time of the rock mass was observed by the SSR after each blast. Post-blast geotechnical inspections and analysis of post-blast deformations in the highwall also did not reveal significant damage to the highwall as a direct consequence of the blasting.

By David Davison

Metafex®* is an inert material that is more energetic than explosives when activated. Because Metafex is inert until activated (a moment before use), it can profoundly change the logistics of systems and processes that require energetic materials. We have obtained positive test results for a Metafex configuration (called a flat pack) that operates at the practical voltage of ~20 kV. We describe the outcome of the testing and potential uses of the material.

Jan 1, 2006

By Roberto Folchi, Hans Wallin

Having so many norms and technical content of legislation to deal with is a problem that an explo-sives engineer has to face, especially when working at an international level. Each country has its own norms and legislation, sometimes even each other region or state, as if the physics of explo-sions, rock, concrete, and masonry characteristics would change across the borders. Both norms and laws are frequently out of date, being mainly developed at the beginning of the previous century and adjusted, piece by piece, to a technical and political context that is constantly changing, with adjustment being frequently adopted in a hurry, due to a problem arising such as that of internation-al terrorism. Sometime also, norms are not harmonized with those they intend to amend, so required explanations and new adjustments lead to a vicious circle that increases confusion, complexity and depresses the explosive industry.

Jan 1, 2015

By Ian Bell, Saman Nouranian, Shahram Tafazoli, Bahram Sameti, Mahdi Ramezani

"Image-based rock fragmentation sensing in mining and quarry applications includes an important rock boundary delineation step, which is commonly referred to as rock segmentation. This paper presents a novel approach to solve this problem, using artificial intelligence. In the proposed technique, priorknowledge of previously analyzed images is encoded into mathematical/statistical models. A set of human labeled images are used as training inputs. These images are used to train neural networksthrough an optimization process. The networks can then be used in real time for rock delineation. "

Jan 1, 2017

By Robert Hivick, Frank Sames

The control of environmental effects, especially blast vibration and airblast, has become a dominating planning criterion for most surface blasting operations. Compliance with existing regulations is generally achieved through constraints in the blast design, or monitoring programs. Commonly, blast vibration and airblast signals are rated and compared by their maximum amplitude and the associated principal frequency. However, this data reduction limits the interpretation of the influence of varying blast design parameters on the vibration and airblast.

Jan 1, 1999

By Robert Hopler

A detonator is a copper tube about a quarter of an inch in diameter and an inch and a half long, closed at one end and containing in the closed end a small charge of fulminate of mercury, which has been found to be the best explosive for detonating dynamite. The fulminate charge is a very powerful explosive very sensitive to friction, lows or heat and very poisonous. When exploded it has an intense local action, shattering things in its immediate vicinity, but not extending very far away from the explosion. This kind of detonator is intended to be exploded by a spark from burning fuse.

Jan 1, 2014

By Toby Forney, Joshua Schoonover

In typical surface quarry operations, productivity and efficiency related to pit development begin with drilling and blasting efforts. By embedding technology within drilling and blasting operations, blast results can be tailored to benefit the quarry by driving continuous improvement of production. This technical paper will focus on the continuous improvement efforts at a cement limestone quarry in Maryland and how those efforts have impacted mining production, safety, and efficiency with the application of specific blasting technologies.

Feb 6, 2023

By Charlie Brumbaugh

Antarctica with its diverse conditions such as severe cold, high winds, rock and ice structure and limited explosives available posed many obstacles. This paper will give an overall view of the methods used to overcome these obstacles on a daily basis on the highest, driest, coldest continent on earth.

Jan 1, 2000

By Dale Ramsey

During Phase IV of our Landfill Mine Stabilization project at a coal burning power generating station, it was determined that a coal barrier pillar separating two abandoned areas of the deep mine had to be breached prior to expansion of the ash disposal area. The proposed plan by the landfill design engineers involved using a high pressure jet cutting tool to cut a slot to allow water flow to an existing industrial waste water treatment facility. Our plan proposed using explosives to breach the pillar from the surface reducing earth disturbance in a high quality watershed while reducing the project cost and accelerating the project time schedule. Many issues surfaced with the proposed change of using explosives. There were a number of lessons learned from this case history and is the primary basis of this paper.

Jan 1, 2003

By Laurance A. Beck

Safety is the most important aspect of haul road design. Although other aspects of road installation enter decisions on design, the safety of persons using the road has to be foremost for the duration of haul road usage. Other aspects of mad design focus on minimizing truck cycle time and fitting haul roads to the long-term configuration of the mine/quarry or construction project. Roads are often installed at high gradients for a short-term goal, but the long-term benefits are easily shown with lower gradient haul roads which provide better cycle times and lower operating costs.

Jan 1, 1995

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 Nikolaos Petropoulos, Changping Yi, Daniel Johansson, Håkan Schunnesson

The effect of jointing on fragmentation by blasting was investigated experimentally and numerically. Firstly the experimental results were presented. Then the numerical modelling based on the experiments was performed. The same conclusions can be obtained based on both experiments and numerical modelling.

Feb 1, 2020

By Adrian Moore, John Wilson, Alan Richards, Emad Gad

Project C9040 – ‘Structure Response to Blast Vibration’, funded by the Australian Coal Association Research Program (ACARP), involved the investigation of the structural response from blast vibration of three houses of brick veneer construction subject to a wide range of ground vibration levels. This paper summarises the findings of a house subject to vibration levels up to 220 mm/s (8.7 in/s). Damage attributable to blast vibration was not observed until vibration levels exceeded 70 mm/s (2.8 in/s).

Jan 1, 2003

By F Ouchterlony

Soviet precursors to Cunningham’s Kuz-Ram model from 1983 are described. They are rooted in the mean fragment size and Rosin-Rammler (RR) fits to sieving data and rely on approximations. Three versions of Kuz-Ram model are presented and all three are de facto based on the median fragment size x50, even if the term mean is used in the papers. This discrepancy caused Spathis in 2004 to suggest a correction procedure for the Kuz-Ram rock factor A, which was said to explain some of the missing fines in the model. This correction, while applicable to Cunningham’s 1983 paper, does not apply to his 1987 paper in which he presents his own A factor. Common fixes of the Kuz-Ram model’s fines issue are fragmentation models where the fines are mainly generated in a crushed zone around a blast hole. This is contradicted by careful model blasting tests. The lack of a largest block size in the RR function may lead to spurious values of the uniformity coefficient n, e.g. in conjunction with image based fragmentation measurements or crusher modeling. These issues may be solved by using the transformed RR function, which has a largest block size xmax or its replacement by the Swebrec function such as in the KCO model.

Jan 1, 2016

By Richard J. Mainiero, Michael J. Sapko, Marcia L. Harris

Since 1988, there have been thirteen documented incidents in the United States and Canada in which carbon monoxide (CO) is suspected to have migrated through near surface strata into structures or other enclosed spaces as a result of nearby trench blasting or surface mine blasting. From these incidents, there are thirty suspected or medically verified CO poisonings and one fatality associated with these incidents. To better understand the variables contributing to this hazard, the National Institute for Occupational Safety and Health (NIOSH) carried out a small- scale field study to identify key factors that may contribute to the migration of CO through the ground. NIOSH conducted single- hole heavily confined experimental test shots to measure the radial pressure pulse as it propagated through surrounding monitoring holes to determine if a relationship existed between the pressure pulse and resulting CO measurements afterwards. NIOSH also monitored blasts at an airport construction site. Following the detonations, the concentrations of CO, nitric oxide (NO), and nitrogen dioxide (NO2) were monitored for several days in the surrounding satellite holes. The peak CO measurements relative to distances from the shots were compared. Pressure histories and peak particle velocities (PPV) were measured at monitoring boreholes. It was found that the differential pressures recorded within the boreholes give some indication as to the likelihood of CO appearing, whereas the PPV measurements do not seem to be as good an indicator for potential CO migration. In this limited study, changes in barometric pressure had very little influence on removing the trapped detonation products, whereas applying a vacuum to the monitoring holes was effective in reducing the entrapped CO concentration.

Jan 1, 2005

By Darren Thorton, David Sprott, Ian Brunton

Blasting causes movement of the rock and can be detrimental to the accurate delineation of the ore and waste regions within the resulting muck pile. The consequences can be ore loss and dilution. However, ore loss and dilution can be minimized and significant increases in profit can be realized if the movement can be accurately measured. Various methods have been used to measure muck pile movement including poly-pipe, chain and sandbags but these have been either inaccurate or impractical. The Julius Kruttschnitt Mineral Research Centre, JKMRC, has developed an electronic blast movement monitor that provides accurate three-dimensional movement vectors following a production blast. From this information, the ore block boundaries in the blasted bench can be adjusted to compensate for the measured movement and then ore recovery can be optimised. Following initial development of the prototype technology, the JKMRC further developed and demonstrated the system in actual production blasts at an open pit gold mine operated by Placer Dome Inc.

Jan 1, 2005

By William Hissem

The topics in the title line of this article are desirable and applicable to entire industries that exist outside the realm of the ISEE’s readership. But the issues I will discuss herein are specific to those who drill, blast, and excavate rock as part of their business. Civil and site construction projects, mines, and quarries specifically comprise the group who will benefit from this discussion.

Jan 1, 2014