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By Alan R. Gadberry

To resolve drilling and blasting problems, rather than treating symptoms and allowing problems to grow, the mine operator needs to change the way he operates. When a mine operator discovers a drilling and blasting result that he doesn't like, it is easy for him to think of that disappointing result as a problem. More often than not, however, that result is only a symptom of a problem, and the real, underlying problem cause can be seen when the operator looks in the mirror. Symptoms and problems relating to drilling and blasting are resolved when the mine operator makes appropriate changes in the way he manages his operations.

Jan 1, 1985

By Dr. Tristan Worsey, Dr. Jhon Silva-Castro

Confinement is an important aspect of blasting. Reducing and increasing confinement can determine whether a blast design performs properly. Over-confined shots usually have poor fragmentation, higher vibrations, and stemming ejection, and unconfined shots usually have a lot of air blast and fly rock. When talking about confinement in blasting, static confinement conditions are typically referenced. Static confinement conditions are ruled by free faces, shot muck, burden, spacing, stemming, hole depth, toe, etc. All these conditions exist in a static state. Static confinement conditions are generally analyzed before the shot takes place, but once the shot starts, the conditions will change according to the sequence and delay of the shot. Once the shot starts, Dynamic confinement takes place. For the authors, Dynamic confinement is the confinement conditions that exist for the charge when it fires and should account not only for the variables included for the static confinement but also for the time and sequence of the shot. The paper explores the theory of dynamic confinement and its role in influencing blast performance. Time and sequence are the main influencers of dynamic confinement and will be the focus of the paper. How to generate the appropriate timing based on blast design, dynamic confinement, static confinement, and geology will also be discussed.

Jan 21, 2025

By Remi Proulx, Ruilin Yang

The effectiveness of presplit in soft or fractured ground is hard to visualize or quantify. There have been many attempts by the blasting community to measure and quantify the effectiveness of presplit blasts. Various methods have been adapted by different researchers, and the results are debatable.

Jan 1, 2019

By Rhys Baker, Tim O’Brien, Joshua M. Hoffman

This paper discusses this division of power as it relates to the explosives industry. Each branch is responsive to the public and the processes through which each promulgates regulation and legislation require public input in different forms.

Feb 1, 2020

By Ran Tamir

"This document introduces the use of drone generated aerial photography to collect and analyze fragmentation data for both muck piles and post crusher stockpiles in order to support the continuousimprovement process. In tandem with photo analyses software, drone imaging gives mines and aggregate sites a fast, accurate and economical method of benchmarking and optimizing the process of size reduction to spec."

Jan 1, 2017

By Tie-jun Tao, Ming-sheng Zhao, En-an Chi

"Karst landform is a special kind of geomorphic unit which is often accompanied by a large number of geological defects: caves. In blasting engineering, if there are karst caves around the blast-holes, it may result in higher boulder yield and the generation of flying rocks due to the change of burden which is very hazardous for the safety of surroundings. The models of rocks with karst caves from blasting holewere built by the software of ANSYS/LS-DYNA. The results of computation simulation show that thecave can increase more free surface for blasting and leads to a broken zone around itself. Thus rockmass around the cave will fly toward inside and it will result in undesirable result of whole rock mass to be blasted. In addition, the models of rocks with karst caves in different shapes were simulated and thecomputation results show that the caves in round shape have higher load resistance capability than that the caves in rectangle shape. All the simulation results can offer effective guidance for blasting design. The models of rocks with karst caves were built in different distances and shapes from blasting hole by the software of ANSYS/LS-DYNA. The effect of different karst caves on blasting stress and blastingresult were studied."

Jan 1, 2017

By Visitor Makiyi, Chris Batten

Poor coal recovery due to coal damage or loss caused by blasting can have a significant impact on a mining operation. Increasing coal recovery by reducing blast damage can provide a significant opportunity for coal mines to maximise their revenue and reduce their operating costs. This paper provides details on advanced drilling and blasting techniques used throughout the coal industry globally to prevent coal damage and movement during blasting. Typical coal loss and damage mechanisms are explained, along with how each of the applied techniques works to minimise the impact of each mechanism. Key requirements for a coal loss reduction program are detailed with typical design parameters used for each of the methods discussed. The positives and negatives of each method are also provided to enable comparisons and help determine suitability for a particular coal mining operation.

Jan 21, 2025

By Adam T. Young

This paper will describe the process of using low density bulk emulsion as a means to maximize the production of an oversize or “rip rap” aggregate size range (8 inch to 72 inch) that the quarry customer has a market demand for. It will also discuss the pre-blast and post-blast metrics used during the product trials and evaluation.

Jan 1, 2017

By Michael Weaver, Dale Ramsey

Description of Project: The National Gateway Clearance Initiative is an improvement program to achieve a minimum of 21 feet of vertical clearance along CSX Transportation Inc’s (CSX) rail corridor so that double-stacked intermodal railcars can be transported between mid-Atlantic states and their ports to midwest markets.

Jan 1, 2014

By Hairong Zeng, Shahram Tafazoli, Edmond Chow

Blast fragmentation is one of the main parameters for optimizing mineral processing, but reliable data is difficult to acquire, resulting in unpredictable performance and efficiency. Crusher and grinder circuits are designed to process specific rock size ranges. Oversized rocks require extra energy to reduce before feeding into the process, and undersized rocks indicate that the process is not used to its full extent. Blast design is the key to controlling the blast fragmentation, so the ability to accurately monitor the particle sizes is imperative.

Jan 1, 2011

By Emily Johnson, Catherine Johnson, Ben Sonpon, Kelly Williams

The effect of length to diameter of the detonator is compared using Ansys/Autodyn 2-D simulations, the results of which are validated experimentally. It was found that higher pressure comes with a larger diameter, because it will result in more explosive energy being allocated out the end of the detonator.

Feb 1, 2020

By Joshua Hoffman, Braden Lusk, David McLane, John Rathbun

The research conducted previously on Shock-Tunnel Waveform Analysis gave a brief insight into the propagation of a shockwave within a shock-tunnel compared to that of an open air arena test. As a refresher, a shock-tunnel is an energy channeling device used to simulate the effects of a large scale detonation with significantly smaller charge weights; having the ability to conduct tests in this fashion can greatly reduce the costs of testing products.

Jan 1, 2012

By James H. Redyke

In August, 1980, while finishing construction of the new stack, one of the flues mysteriously collapsed, killing three people and injuring several others. Several months later a British international steeple-jack company was hired to demolish the remaining portion and make a detailed inspection of the balance of the chimney. During this contract almost one hundred core samples were taken from all parts of the structure including the 32-inch thick base. As the result of these tests and the investigation, the Power Company decided to demolish the complete structure. Because of the critical time element, the decision was made to use explosives in the removal of the structure. To give you some perspective as to the size and dimension of the stack, it was 900 feet tall, 80 feet in diameter at the base, and 70 feet in diameter at the top. The two remaining flues were 25 feet in diameter and extended 30 feet beyond the top slab of the chimney. The outside of the structure was referred to as a wind shield. The lower 120 feet were 32 inches thick and the remaining 780 feet were 12 inches thick. The decision was made to prepare and shoot the chimney at the 120-foot elevation because the debris from the collapsed flue was confined in the base section and could not be easily removed. After extensive and costly engineering, we determined it was necessary to construct steel columns to bear on the lower 120-foot section, which would act as a hinge and guide during the dropping of the structure.

Jan 1, 1982

By Midori Sakamoto, Nobuaki Sakuma, Tsuyoshi Murashita

Recently, tunnel blasting works near the residential area and existing building are increasing and environmental problems caused by vibration have become serious public concern. In order to solve these problems, blasting works have been conducted with segmented blasting and reduce advance per round. However, with these blasting, work efficiency is not obtained, and regrettably the cost and risk of accident tend to increase. We developed a new controlled tunnel blasting technique with electronic delay detonator. Electronic delay detonator can supply extremely large range of delay period which could not be achieved with conventional pyrotechnical delay detonators. We utilized advantages in initiating hole by hole over entire tunnel face at the same round. Much seismic data obtained from tunnel blasting with conventional detonator was statistically analyzed in order to find average duration time of vibration caused by a single hole initiation. Numerical simulation using sample waves from a single hole initiation was carried out in order to find an optimum delay time which can separate vibration in each hole initiation and without decreasing blast performance. Trial blasting was conducted to examine the correctness of optimum delay time obtained from numerical simulation. This blasting technique was applied to an actual tunnel construction. This tunnel is 2 lane automobile tunnel with a total length of 659 meters and internal cross section of 70 square meters. The purpose of the use of blasting technique on occasion, was the protection of fresh water reservoirs directly above the tunnel, and to keep the effect on local private houses to a minimum. The vibration level against this station was limited under 20 mm/see P.V.V. With this blasting, the tunnel construction was completed without exceeding the limited vibration level, with minimum cost and construction time.

Jan 1, 1998

By Stephen John Brace

Increasingly, electronic blast initiation systems are being made available to the mining and construction community, both in South Africa and internationally. Indeed, in some parts of the world, perhaps half a dozen electronic products are being used, with a choice also of shock tube, electric and fuse and igniter cord systems. As these developments have taken place, improvements have been made in safety, reliability and accuracy, so much so that high performances in all these areas are now expected. However, disadvantages often seen by customers, other than : higher price, are decreased user-friendliness and loss of flexibility.

Jan 1, 1998

By Carlos Neto

Traceability is the capacity to recover background, application or localization of an item, through a single, standard and registered identification. It is the identification process necessary to follow all events, occurrences, handlings and movements of a product. Generally speaking, companies and governments in the world are seeking ways for tracing the distribution of controlled products, such as food, medicines, firearms and explosives, within the supply chain as to increase safety of its consumers and the environment (ISO 14000).

Jan 1, 2007

By Jason Wilkinson

Drilling operations are a vital component of surface mining, directly influencing productivity, safety, and cost efficiency. This paper explores a multi-faceted approach to drill optimization, focusing on minimizing delays, and enhancing operational effectiveness. Key areas of inefficiency such as shift changes, fuel and water delays, and time lost between drilling holes are analyzed to identify actionable improvements. Equipment related factors, including the frequency of drill bit and drill steel changes, as well as the condition of deck bushings, are evaluated for their impact on downtime and performance consistency. Additionally, the integration of smooth drives and shock subs is examined for their role in reducing vibration related wear and improving drilling precision. Optimization of pattern approach strategies is highlighted as a means to reduce non-productive movement and align drilling with blast design more effectively. To support continuous improvement and accountability, the implementation of a driller scorecard is proposed. This tool enables the measurement of individual performance based on key operational metrics, fostering a culture of data driven management. Through a combination of field data analysis and best practice recommendations, this study provides a comprehensive framework for enhancing drilling productivity in mining operations. The findings aim to support mine operators in achieving higher efficiency, reducing operational costs, and extending equipment life through targeted optimization strategies.

Jan 26, 2026

By Ann Barron, Paul Downing

Those employed in the explosives industry must have a keen familiarity of the explosives products they handle, the safety pro c e d u res they must follow, and the increasing number of laws and regulations governing blasting operations in order to perform their duties satisfactorily. For this reason, companies must make certain that their employees have the necessary knowledge and full understanding of their blasting and non-blasting responsibilities. Consequently, training is one of the most important elements in any company’s safety program.

Jan 1, 2004

By Corry Goumans, Dan Agostino

Photo 1. Demolition work on the Pitt River Bridge. The drill crew is using the 3800 Gardner Denver Air Track to drill the holes on the Bridge turning dolphin. The barge in the background is used for support.

Jan 1, 2013

By Estefania Aramayo, Jhon Silva, Todor Petrov

Blasting is one of the most critical activities in a mining operation. Nowadays, many quarries have to follow a considerable quantity of environmental restrictions that drive the need to improve the conceptualization, design, procedures, and execution of the blast to comply with all regulations. Airblast is one of the variables required to control when blasting. Airblast is an unwanted side effect of blasting. Airblast is defined as an airborne shock wave resulting from the detonation of explosives. Traditional methodologies used for assessing the overpressure produced by the airblast are based on empirical approximations that require the collection of a series of produced airblasts before they can be used as a predicting tool. Once the data is available, regression analysis methodologies are used to find the constants of empirical laws that, in most cases, establish the relationship between the distance and the weight of explosives used in the shot (scaled distances laws). If using the traditional methodologies, the quality, and representativity of the scaled law established for a particular project are determined in terms of the correlation coefficient; in most cases, the models and their use as a predicting tool are questionable (very low correlation values).

Feb 6, 2023