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By B Mohanty, M Alam, F Gauthuer

A series of eleven full-scale production blasts has been earned out in a limestone quarry to study the effect of delay interval and its precision on overall blasting performance. The quarry employed ANFO and cartridged aluminized emulsion in 75 mm diameter boreholes with 2.6 m burden and 2.9 m spacing on a 6.7 m bench. Both V-cut and echelon designs were studied. The types of detonators tested were regular short period electric detonators with expanding delay intervals, a more precise pyrotechnic-based electric detonator (EXADET) with a fixed (25 ms) delay interval, and the ultra-high precision electronic delay detonator (EDD) with constant (but site-selectable) delay interval. The various techniques employed to assess the blast results are described, and the performance of the three types of detonators compared. The use of both EXADET and EDD lead to improved blast results in echelon design. Of the three delay intervals (25 ms, 38 ms, and 50 ms) studied, the best results were obtained with EDD with a 38 ms delay interval, which translates into a delay of 38 ms/m of effective burden. The results also show the need for modification of current V-cut delay designs to derive full benefits from these high precision detonators.

Jan 1, 1991

By Jianping Li, Ernesto Villaescusa, Kelly Fleetwood

During blasting, stress waves propagate through a rock mass, inducing stress and strain changes. This applied deformation affects intact rock, existing discontinuities, mine excavations, and engineered structures in the proximity of the blast. Traditionally in blasting, stress waves are quantified in terms of peak particle velocity (PPV) or peak particle acceleration (PPA), based on the method of measurement and the specified allowable tolerances. During analysis, the peak particle motion is coupled with an explosive source through various scaling laws to develop rock-specific attenuation relationships. Some studies have expanded this practice to the development of damage threshold values based on measured or predicted peak particle velocities. PPV-related thresholds are generally based on empirical models, where observation of overbreak, cracking, or fall-off are used to quantify damage. This method is often paired with the application of elastic plane wave equations to calculate the blast induced strain or the PPV threshold for tensile rock failure. Other factors that must be viewed critically in such models are the methods used to collect and analyse blast vibration data and the application of inappropriate vibration attenuation relationships.

Jan 1, 2009

By Orica

Unlicking the Possibilities ISEE Digital Detonator Workshop New Orleans, LA Wednesday, February 4, 2004

Jan 1, 2004

By Wang Xuguang, Tian Ruigi, Xiong Shangbin, Xiong Daiyu

Combining action features of explosive shock with those of natural lignocellulosic biomass structure, we have successfully developed a new explosive shock dilatation and separation technique for pretreatment of natural lignocellulosic materials in the laboratory. Based on a brief introduction to the technical background and experimental procedure of this new method, some preliminary experimental results are given and discussed: the scanning electron microscope (SEM) qualitative observation results show that for treated natural lignocellulosic sample such as corn cob etc., their length of fibre bundle shortens, fibre bundle arrange disorders, biomass appearance and structure of samples largely change to be dilatation and loose state. The dilute acid hydrolysis quantitative measure results show that for treated samples, the overall yield of the reducing sugar largely increases, hydrolysis rate of corn cob sample is over 80%, rate and speed of hydrolysis are increased by times.

Jan 1, 1998

By Julijan Bratun, Joze Kortnik

Production of technical stone is an important economic branch in Slovenia. In 2009, we had 95 dolomite quarries, 27 limestone and 6 silicates quarries, according to the Ministry of Economic Affairs. Together they produced nearly 15 million tons of aggregates. The production in quarries is mostly performed with drilling and blasting method and only a minor part with other method like mechanical mining method.

Jan 1, 2011

By Gordon Lovegrove, Jeffrey Leob, Dwayne Tannant

It has long been known that the combination of aluminum (AL) powder to ammonium nitrate (AN) / fuel oil (FO) can greatly enhance fragmentation or ultimately reduce the number of blast holes in a pattern. Decades of research have meticulously provided optimal AL:AN:FO ratios showing dramatic increases in energy output levels, yet widespread use of aluminized ANFO (ALANFO) has yet to replace the use of ANFO in the blasting world today. This may be due to the perception that the upfront, increased cost of materials deters the selection of this advantageously modified explosive. Researchers have explored this question and promote ALANFO by pledge of massive reductions in day-to-day operational costs. However, in these analyses there is a complete disregard for the external costs of the material; the environmental effects and sustainability considerations of the product. A holistic social cost-benefit analysis of ALANFO shows that an admittedly high-cost explosive does indeed provide an output which contains a wealth of operational savings in typical blast patterns. However, the immediate, on-site costs and savings do not define the limitations of this analysis. A complete comparison of the externalities including the environmental and sustainability considerations of the aluminum by-product life-cycle, and the environmental impacts of both the refinement of ammonium nitrate prills and the acquisition of sufficient fuel oil are also assessed. A savings of $216,000 / year through the use of ALANFO in one particular case study was recalculated to an increase in drilling and blasting costs of $188,000 when the external costs of aluminum, ammonium nitrate, and fuel oil are included analysis. The results of this analysis are intended to improve contractors? selection of explosives by providing additional societal and environmental factors into the equation, in preparation for an exponential global shift to greener business operations, while allowing them to remain competitive.

Jan 1, 2011

By T. G. Sitharam, P. B. Choudhury

Prediction of ground vibration (peak particle velocity, PPV) and frequency is an important task in geoscience. Till date, many empirical equations are derived from conducting trial blasts in the mines, to arrive at attenuation predictors. These predictors are usually site dependant and hold good for one particular type of rock/strata. These predictors cannot be used for geologically different rocks/strata. This paper presents the application of support vector machine (SVM) model, for predicting blast induced ground vibration and frequency, using a one comprehensive model for three different types of rock. Inputs to the SVM model formulation involve twenty one parameters consisting of geotechnical properties of the rock mass, blast design geometry and explosive properties, and the output of the formulated model is peak particle velocity and its associated frequency. The data has been acquired from eight limestone mine, five coal mine and two manganese mines. The comprehensive SVM model is formulated using 400 datasets and tested with 143 datasets. The performance indicators to the model not only justify its formulation but also the advantages it has over site specific predictor models. The SVM model not only predicts PPV, with higher correlation coefficients as compared to predictor equations, but also the associated frequency.

Jan 1, 2010

By Ali Kahriman, Abdulkadir Karadogan, Alper Celtikci, Ahmet Varol, Ertugrul Kaya, Turgay Ozat

This paper presents analysis of environmental effects induced by cautious blasting during the construction of the Istanbul Subway 4 Levent - Ayazaga Darulsafaka Metro Tunnel Project carried out by the contractor, located at Northern Istanbul in Turkey. Within the scope of the study, for the prediction of the peak particle velocity and to determine the slope of the attenuation curves together with the maximum charge per delay for the S6-7-8 shafts of this tunnel route, ground vibration components were measured carefully by using five vibration monitors during the construction of the tunnels which required blasting. The particle velocities and frequency values of all blast events are evaluated according to the United States Bureau of Mines (USBM) and German DIN 4150 Norms in order to predict, and compare the influence grades to the neighboring buildings, and structures. Also, data pairs of scaled distance and peak particle velocity obtained from 107 records belong to 51 shots were analyzed statistically. Empirical relationships with correlation at the 95 % confidence interval were established for these tunnel excavations and suggested for the test sites in order to estimate particle velocity of the ground vibrations. As a result of the studies, some practical charts are created in order to minimize the psychological effects of the shots, and simplify the authorities of shots’ job. And last but not least, make sure that the shots will be done in a controlled way.

Jan 1, 2011

By Thierry Bernard, Pierre M. Vuillaume, Michel Kiszlo

"In the context of its studies for the trench ministry of the environment and for the French national coal board, INERIS (the French institute for the industrial environment and hazards, formerly CERCHAR) has made a complete critical survey of the methods generally used to reduce the levels of blastingvibrations."

Jan 1, 1996

By C. Adcock, R. Farnfield, G. Adderley

The use of explosives to create special effects in the film industry is a well-known past time. A recent production required simulation of a large scale water splash from the effect of a statue falling from a cliff edge and impacting on an open body of water. This was to be achieved through the use of precisely delayed explosions detonated near the surface of the water. A survey of the area revealed a breeding farm for sea bass approximately 250 metres (273 yards) from the intended blast area. It was initially thought that the water pressures produced for the detonation of the explosives may cause harm to the fish. Much work has been carried out over the past few decades on the effect of open water blasting and its effects on aquatic wildlife; this includes water pressure modelling techniques which can be used as predictive tools.

Jan 1, 2010

By Steve Dillingham

The origin of the written blasting log or shot report can likely be traced back to the earliest annals of blasting and record keeping. These records were, for the most part, a way of checking inventory, production progress, or billing, and not necessarily designed with the intention of being used as a legal document in a court of law. As our litigious society has evolved to include far reaching regulatory requirements, however, the blasting log has developed to support and aid in the defense of the common blaster from blasting lawsuits by providing a comprehensive written report of his or her actions.

Jan 1, 2002

By S. Evans, J. Phillips-White, D. Morton

The partnership between Orica and MMG at the Dugald River Zinc mine in Australia has led to the first global field trials and deployment of Orica’s Subtek™ 4D™ (hereafter referred to as 4D) Bulk Systems underground bulk emulsion blasting technology. This technology offers advantages over conventional bulk explosives by extending the range of energy and length of explosive column that can be charged in underground production. 4D gives blast designers energy options between Relative Bulk Strength (RBS) 50 - 150, delivered uniformly along the entire column in most blasthole conditions along with the ability to instantaneously modify the energy within an individual blasthole. During Phases 1 – 3 of the project from October 2022 to January 2023, over 57 tonnes of the 4D Underground emulsion were loaded in 17 stopes. The primary objectives of this phase were to reduce hanging wall dilution and improve stope recovery. While drilling and other parameters remained unchanged, the energy selection was tailored for specific situations, guided by a revision to the site's drill and blast standard. The design used low energy (RBS 50 - 70) in holes adjacent to the hanging wall and high energy (RBS 130 - 150) where stope recovery had historically been challenging, such as at the toes of long downholes. Initial results of the project focused on five stopes selected for their similarity to those used for the baseline data set. Although the 4D data set was small, the post-blast scans indicated favourable results for recovery and dilution. This suggests that selecting and delivering bulk explosive with tailored energy levels can improve stope performance.

Jan 1, 2024

1974 The Society of Explosives Engineers officially formed to “advance the art and science of explosives engineering” on August 20, 1974 in Pittsburgh, Pennsylvania.

Jan 1, 2010

By Kush Patel

This paper presents methods currently available for the evaluation of bulk explosives and discusses the results of the evaluation of bulk explosives using each of the methods. Through the preliminary experimental analysis, wet chemistry and the Bulk Explosive Analyser were found as methods most suitable for the evaluation of bulk explosives. This paper also presents data obtained from the experimental comparison of the wet chemistry method and the Bulk Explosive Analyser.

Feb 1, 2020

By N. Skopak, C. Aimone-Martin, J. Redyke, B. O. Meins

PipeBlast is a spreadsheet-based calculator based on research conducted by Southwest Research Institute (SwRI), used by the pipeline industry to determine if proposed blasting planned near existing pipelines can be safely executed. The two factors determining “safe” are blast-induced pipe wall hoop stresses and predicted peak particle velocity (PPV) at the pipeline. Although methodology used to predict hoop stresses is somewhat sound, predicted PPV amplitudes are highly exaggerated based on inappropriate attenuation models developed using spherical explosive charges of limited charge weights, placed in soil adjacent to model pipelines that do not represent rock blasting. Hence, pipeline companies readily reject well-design blasts and limit scaled distances far beyond what is reasonable and cost-effective to pipeline owners. Full-scale trench blasting in rock was conducted near a 24in (711mm) diameter operating API 5L X70 grade steel pipeline in Texas to compare PipeBlast model predictions with a Ground Strain Model (GSM) based on field measurements of ground motions on the surface and at the pipeline springline. Results of the GSM were compared with pipeline strains measured using wire gauges mounted on the Springline. The comparative results showed that a site-specific velocity propagation model provided good estimates of ground strains that are replicated on the pipeline walls in terms of hoop and longitudinal strains. Trench blasting 28ft (8.5m) from the pipeline produced ground motions of 7.6in/s (193mm/s). At this ground motion amplitude, the factor of safety defined as the allowable stress divided by the combined operating and blasting hoop stresses was reduce from 3.04 in the absence of blasting to 2.98. This paper explains the research and findings on which PipeBlast is based and presents an alternative approach to predicting blast-induced pipe wall stresses based on site-specific velocity propagation measurements and a ground strain model.

Jan 1, 2024

By L D. Lawrence

Certain blasting applications are more prone to the generation of significant levels of nitrogen dioxide post blast fumes, more commonly referred to as after blast smoke, generally ranging in color from dark yellow to bright red. This paper reviews basic background chemistry defining the observed fumes and attempts to correlate geology, blast design, and explosive composition effects on the level of nitrogen dioxide that can be observed in various blasting conditions. Additionally, a test setting for evaluating the generation of post blast fumes is presented with pertinent test data detailing generic explosive formulation modifications which effect the overall level of post detonation generation of nitrogen dioxide.

Jan 1, 1996

By D. Fry, S. Hunsaker

Ammonium nitrate in explosives and sulfides in reactive ground have the potential to react at ambient and elevated temperatures resulting in premature detonations. The Australasian Explosives Industry Safety Group (AEISG) published, in 2006, a Code of Practice1 for elevated temperature and reactive ground. This paper reviews the chemistry, general reactivity of various ground types, elevated temperature hazards, and testing protocols contained in the code, that are industry best practices for managing ammonium nitrate-based explosives in elevated temperature and reactive ground conditions. In addition to reviewing the 5th edition AEISG Code of Practice, data is presented validating the recommended sampling guidelines within the code. Dyno Nobel has been screening reactive ground samples and performing sleep time testing since the code of practice was first released. Test results demonstrate the effects of samples that are allowed to oxidize before testing and are shown to be subsequently less reactive and not representative of the actual hazards facing mining blasting operations. Results also show that for a given reactive ground sample, reaction times decrease with increasing temperature. Data also quantify the delay in reaction time given by inhibited products. These results emphasize the importance of proper sampling and preparation of samples to accurately characterize elevated temperature and reactive ground hazards. They also demonstrate the efficacy of inhibited products in managing these hazards

Jan 1, 2024

By Hector O. Romero, Paulo C. Fernández A, Claudio C. Gajardo

Phase 06 of the Los Bronces mine, currently under extraction for development, has the particularity of being close to the installations and buildings of a neighboring copper mine. Therefore, the blasts must ensure the continuity of the operation without affecting the nearby structures of the neighboring district, which include Maintenance sheds and Warehouse. Specifically, the safeguards consider a scenario that includes: - Flyrock projections (<150m) - Edge profile studies - Vibrations according to the NCh3577 standard - Nitrous gases Additionally, Phase 06 is also within Los Bronces, so strict control over spillage into the pit is necessary to avoid blocking ramp access to this level. The challenge lies in protecting not only the operation and facilities of the neighboring mining district but also the operability of Los Bronces. Thus, addressing these considerations, blasting configurations are developed with prior simulation of vibration models, flyrock, and spillage in all blasts, with strict control of technical design and implementation to ensure the results. Currently, blasts are successfully executed with control of projections based on the proximity of the projects, vibration (<40mm/s) with decoupling of holes of 17 mm/s between holes, reactive rock tests for explosive selection (loading advancement), and spillage simulation inside the pit according to the loading design; thus, ensuring operational continuity and mine development.

Jan 21, 2025

By Wm. Reisz

There is no universal standard for Standard Operating Procedures (SOP’s). Every blasting operation has its own unique circumstances, its own methodologies and its own unique demands. It would be nearly impossible to create a one-size-fits-all document that would be totally appropriate for every blasting scenario. But there are universal objectives that should be adopted in any set of blasting SOP’s.

Jan 1, 2010

By Amos Bryant, Jesse Davis

This paper compares the predictions of the latest Institute of Makers of Explosives Safety Analysis for Risk (IMESAFR) model versus physical test data recovered from ISO-1 and ISO-2 tests in Woomera, SA. ISO-1 testing included placing 1054 kg (2324 lbs) of ANFO (ammonium nitrate-fuel oil) inside an ISO container on a flat bed truck. ISO-2 testing was identical except the NEW was 4000 kg (8818 lbs). The IMESAFR predictions are based on model runs using the best match available to the actual donor type involved in the test. This type of debris analysis is not the standard output of IMESAFR, as the program is designed to assess the probability of human fatality. However, all of the IMESAFR predictions presented were obtained from the use of the actual model equations and algorithms without adjustment. Test results from ISO-1 and ISO-2 will be presented as well as findings from the comparison between model results and actual explosive results from the ISO testing efforts.

Jan 1, 2010