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By Matias Suarez, Diego Zenteno

It is known that the introduction of electronic timing in the sequencing of blasting has changed the vision and way in which mining is developed. It is possible to deal with more complex and sophisticated drilling designs, without compromising productivity or safety. It has been shown in various studies, that a correct timing of the blasting provides an improvement in the improvement of the processes downstream, due to a decrease in the resistance of the resulting fragments coming from the interaction of the waves generated in the detonation of explosive loads. On the other hand, it has also been shown that variations in the composition of a same type of explosive, has a significant influence over the resistance of the blasted material, also the energy associated to break it, affecting directly its degree of fragmentation. This paper is aimed to display the new advancements of blasting engineering done in different mining sites throughout the country, associated to electronic sequencing, energy of the explosive and its impact on the fragmented rock. This document explains how to define and implement selective sequencing in the blasting in order to promote the propagation of cracks, therefore impacting positively the productivity through the use of the LaGrange diagram. The LaGrange diagram is a very convenient and illustrative method to present the dynamic behavior associated with wave and crack propagation (Rossmanith. H, 2002). This study focused on the methodology of the formation and measurement of seismic pulses, through the rock massif. For this purpose, seismic pulses were acquired in the field and then, the different dynamic phases of the wave were molded mathematically, with the purpose of favoring the coupling between them.

By Ryan Brogden

On the 5 September 2014 a road train (tractor-trailer) with two trailers carrying ammonium nitrate was involved in a single vehicle accident on the Mitchell Highway, 30 kilometers (18 miles) south of Charleville in Central Queensland, Australia. The ammonium nitrate was being transported to a mine site for use as a blasting explosive. The truck came to rest in the creek bed adjacent to a road bridge and caught fire. The vehicle burnt for over one hour before the load of ammonium nitrate exploded. Miraculously there were no fatalities; however eight people nearby sustained injuries, some seriously. The road and rail bridge over Angellala Creek were destroyed and vehicles in the nearby vicinity were seriously damaged. The truck carrying the ammonium nitrate was completely destroyed with over 2500 pieces of debris scattered up to one thousand yards (one kilometer) from the blast site.

Jan 1, 2018

By Luis Huaroc, Augusto Sotomayor, Erick Rodriguez, Paulo Fernández, José Ricaldi, Luis Alejandro

The application of the Kuz-Ram model for the prediction of fragmentation is used worldwide, in Coimolache Mine it was used to determine blast domains and optimize the process by obtaining drilling patterns that meet a required X80 and reducing the uncertainty of drilling.

Feb 1, 2020

By Donald Jonson

The Arlanda Link project is for the time being the most interesting project in Sweden, concerning rock and blasting technology. The total amount of rock excavated beneath Arlanda airport comprises 800 000 m³ divided in four parallel tunnels measuring a total length of 8,5 km, with a rock covering of only 5-15 m between the tunnel roof and existing terminal buildings.

Jan 1, 1997

By Amund Bruland, Vegard Olsen

This paper presents analytical assessments around unintended misfire detonation, within rock debris drilling and bench top cleaning, primarily in the quarrying and mining industry. The main purpose of the work has been to see which operation has the lowest fatal accident probability. To be able to do this a risk analysis model is developed and the basics of the model are described first in the paper. Further a practical approach of the model use is presented. This includes a summary of general fatal injury statistical data, which is used to establish input parameters in the model. The result of the work shows that the rock debris drilling operation has at least half the probability of fatal injury compared to bench top cleaning. The result of the work should bring along rewriting of the Norwegian explosives regulation. The statistical data also shows that the blasting industry generally has a high fatal injury rate compared to other industries and basic risk reference levels. Risk reduction efforts concerning the examined operations are described.

Jan 1, 2008

By Alastair Torrance, Braden T. Lusk, MinGi Seo, Gary Cavanough

Velocity of Detonation (VOD) is the most commonly used method to determine explosive performance as VOD is a function of the confinement (ground conditions) density and composition of the explosive. Techniques used to measure VOD include resistance wire, time domain reflectometry, simple start stop and fibre optic methods. All these approaches require a cable of some sort to be inserted into each blast hole being monitored and the holes to be fired in a specific sequence. It is time consuming and fairly technical to position the cables correctly to gather the data from each hole. It slows down the hole loading process and increases the number of people on a bench at that time. The equipment and cable limits the measurements to a few holes, typically 5 or less, that are in close proximity. These measurements can generate useful information about the monitored holes but does not provide a full picture of how the explosive is performing across the whole blast and whether any change in performance is noted with changing ground conditions or confinement.

Jan 1, 2019

By David Hersey

The Paseo Bridge was located at the I-29/I-35/US-71 Missouri River Highway Crossing. It was built between 1952 and 1954 by Massman Construction Company. The 1,232 foot long, self-anchored suspension bridge was the longest of its type when built. On Jan. 22, 2003, a connector pin designed to allow the bridge to expand and contract during temperature cycles seized and caused a portion of the bridge deck to raise up and block traffic. This marked the beginning of the end for the old Paseo Bridge.

Jan 1, 2013

"Recently, an effort was made to calibrate the Riedel-Hiermaier-Thoma (RHT) material model to reproducethe behavior of granite under impact and explosive loading conditions. The study concluded that the materialmodel captured the phenomenon of compressional damage in granite due to such loading conditionsfairly well. The present work uses hydrodynamic modeling with the calibrated RHT model to estimate thefines generated around a blasthole. This can improve the calibration of different size-distribution empiricalmodels and enhance the prediction of fines."

Jan 1, 2012

By B T. Lusk, Jhon J. Silva

"The original signature hole technique to predict vibration levels from blasting, is based on theassumption that each hole in a production blast, generates an identical vibration waveformarriving to the point of interest. When the same waveform is used to represent the vibrationproduced by each hole, the complete waveform for the whole blast is the convolution betweenthe waveform and the impulse sequence that represents the initiation timing of the blast. In thisresearch, several field tests were developed to establish the validity of the invariability of thewaveform hole-to-hole in a mining production blast. The results of the tests showed that thereare variations in amplitude and frequency content for the hole-to-hole waveforms. Thevariations can be explained due to the character of the parameters involved in a production blastbetween them: different vibration path for each hole, differences in the geometry of each hole,differences in the explosive charge for each hole (chemical and quantity), etc. This paperdescribes a methodology based on the main characteristics in both; time and frequency domainof any recorded signature waveform and uses Fourier series to approach one equation to generatedifferent random waveforms for each hole that can be used in the prediction of the completevibration record of the blast. The methodology is the base for signature hole analysis using aMonte Carlo scheme."

Jan 1, 2012

By Brian Hawkins, David Bradley, Rachel Gooding, Lucas Rodriguez, Patrick Wilson, Kevin Wegman, Dhruv Mittal

To better protect the nation and inform difficult defense and preparedness decisions, the Department of Homeland Security (DHS) is performing a probabilistic risk assessment of explosive terrorism risk to the US homeland. After assessing existing models against requirements, well-developed mathematical descriptions and algorithms associated with explosives hazards were combined with probabilistic modeling techniques used in DHS chemical, biological, radiological, and nuclear (CBRN) terrorism risk assessments to create a suitable interior explosive consequence model for assessing the impact to human health.

Jan 1, 2018

By P D. Katsabanis

Explosives malfunction due to shock waves is a serious concern for successful blasting results. Malfunction includes sympathetic detonation and desensitization of explosive charges as well as the modification of firing times of conventional pyrotechnic detonators.

Jan 1, 1995

By Thomas L. Barkley

This paper describes an unusual design for a 12 foot diameter, 30 foot deep circular shaft shot in a close in urban environment less than 100 feet from occupied structures. It uses diagrams, video footage, and vibration results to describe a 3 deck, 17 hole burn round used to pull 17 feet in one lift.

Jan 1, 1994

By Jeff Wachendorf

As the title "Cast Blasting Around Town" implies, this paper details the starting of a cast blasting program in and around the town of Colstrip, Montana. As strip ratios have increased, the need to adapt and find solutions to provide coal at a reasonable cost to the captive power plants has risen. Colstrip, Montana has a long history of coal mining which dates back to the early 1920's when Foley Brothers began supplying coal strictly for powering locomotive engines. Early mining days starting in the 1920's and the progression up through the 1970's when mine mouth power plants were built will be discussed. To accomplish the desired results, early mining techniques included steam and electric powered equipment as well as a lot of actual horse power.

Jan 1, 2009

By Dan McCutchen, Oettmeier

Kelly bar drilling and blasting is unique to Florida, the' Bahamas and other marine limestone areas in the world where blast holes are required but will not remain open for the loading of explosives. This type of rock formation usually yields 1.5 tons of recoverable rock compared to 2.2 tons per cubic yard for competent limestone. The loss of .7 tons per cubic yard is due to voids and sand in the formation. These deposits all contain water to the top of the blast holes which are collared only a few ft. above the ground water level. The working pit is a water filled lake which is excavated from the bank by draglines. These drills have been used in Florida for many years to depths of 65 ft or less.

Jan 1, 1991

By Richard G. Burdick

The use of explosive charges for generating seismic energy has been around for a long time. For oil-field work or crustal studies, when the target of interest is many thousands of feet deep, the surface waves and similar phenomena are of little consequence. In mining applications, however, when the target is a few tens or hundreds of feet deep, the return signals are often masked by these waves and an accurate interpretation is difficult or impossible.

Jan 1, 1981

By Tyler Ross, John Tatom, Lon Lantis

The Institute of Makers of Explosives (IME) began development of a Quantitative Risk Assessment (QRA) tool, IMESAFR (Institute of Makers of Explosives Safety Analysis for Risk), in 2005 as a technology transfer effort with the United States Department of Defense (US DoD). Version 2.0 of the software has been developed over the last two years and introduces many new features and upgrades. Key upgrades include a new map-based user interface, new debris density hazard models, a metric version, and additional user options referred to as “conservatism switches”.

Jan 1, 2014

By Saeed Karimifard, Saman Nouranian, Shahram Tafazoli, Bahram Sameti, Frank Chu, Caitlin McKinnon, Tetiana Konstantynivska, Glen Turner

We propose a particle size analysis solution for haul trucks that does not impact current operational workflows. Using artificial intelligence (AI) and 3D imaging technology, our solution reliably localizes and identifies haul trucks as they drive by, then accurately calculates the particle size distribution of the visible material in each truck load. In this paper, we identify the challenges of designing and implementing the proposed solution and explain the strategies we employ to overcome these. We also discuss a method for boulder detection that leverages the existing deep learning architecture to significantly reduce crusher downtime caused by oversized rocks

Feb 1, 2020

By D T. Froedge, Michael J. Nutting

A system consisting of an unlimited number of biaxial geophones that measure peak particle velocity and frequency has been developed and utilized at surface mines, quarries and construction sites. An ability to accurately measure ground vibrations completely surrounding a blast and to construct a vibration topograph has facilitated the study of blast design parameters and geologic factors on the resulting generation and propagation of the vibrations.

Jan 1, 1990

By Donald Jonson

Stockholm’s Northern Link, currently Europe’s largest urban road tunnel project, will be about 5 km long from west to east. Running through two separate, mostly parallel tunnels, each with 2-4 lanes, the complex will include numerous entries and exits, as well as a major branch to the north. The total length of tunnel will be 11 km, of which 9 km will be in rock. Over million m3 of rock will be blasted. The Northern Link will open to traffic in 2015. After a 10-year stop to deal with environmental questions regarding Ekoparken, Stockholm’s unique “national city park”, the Northern Link project in the Swedish capital was restarted in the autumn of 2006, with the construction of five works-access tunnels.

Jan 1, 2009

By Clive-Workman Davies, K K. Kabongo, Mensah Frimpong

Given the capital intensity of the dragline operation coupled with rising cost of explosives, the onus is on mine operators to make maximum use of explosives in blasting to assist dragline diggability. At a surface coal mine in South Africa large boulders necessitating secondary breakage and in some cases completely unfragmented sections of a blast resulting in low dragline diggability were encountered in the interburden blast. Twelve blasts were therefore closely monitored and dragline productivity evaluated. The ultimate aim was to improve the overall blasting performance and hence increase dragline productivity. Three areas were in focus; fragmentation assessment, dragline productivity assessment and cost analysis. The studies indicated unsatisfactory explosive and initiation performance, problematic blast design and questionable operators performance. It is established that dragline cost account for 60% of the total mining cost whereas the drilling and blasting cost account for the remaining 40% and that improvement in dragline productivity results in automatic cost saving.

Jan 1, 1996