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By Don Z. Painter, Gordon F. Revey

Frontier/Traylor Joint Venture is presently constructing a section of the Tri-County Metropolitan Transit District of Oregon's (TRI-MET) Westside Light Rail system. This new section will extend Portland's existing transit system to the western suburbs of Beaverton and Hillsboro. The drill-blast excavations at this project include 10,000 feet of 20 foot tunnel, 18 cross passages, three shafts, an underground railway station, and a U-wall open cut. From a blast designer's perspective, this job has been extremely challenging. Blast vibration is limited to 0.5 ips at 200 feet or at the nearest structure, and airblast is limited to 129 dB -- linear peak and 96 dB -- C scale. The tunnels pass under heavily built up areas and have top of tunnel to surface cover distances as low as 70 feet. Surface blasting in the 26,000 cubic yard U-wall excavation was limited to five short nighttime periods due to its proximity to the very busy highway 26.

Jan 1, 1995

By Tom Barry, Kameron Ray, Dr. Gavin Yuill

Imerys Talc, Yellowstone Mine in Montana faces significant geotechnical challenges such as poor wall quality and local instabilities. These instabilities are driven primarily by the characteristics of the rock mass, but are aggravated by drilling and blasting operations.

Jan 1, 2016

By Piotr Mertuszka

Many years of research on more effective and safer explosives have led to the development of emulsion explosives. They are the second most commonly used group of explosives worldwide, primarily because they are good alternatives to ANFO or dynamites. Their key advantage in underground applications is the lower content of toxic fumes in the detonation products. Emulsions are also characterized by high detonation velocity, high water resistance, low critical diameter, and mechanical loading capacity. Several factors affect the behavior of emulsion explosives. These factors are related to both manufacturing and applied mining methods. The most important factors include the charge diameter, type of sensitizer, density, hydrostatic pressure, ambient and charge temperatures, as well as the time elapsed between the charging of the explosive into the blast hole and its detonation. The selection of the type of explosive is based on the analysis of a number of parameters, including the density, critical diameter, volume of the post-blast fumes, detonation pressure, velocity of detonation, and sensitivity to external energy sources. In most cases, the conditions under which explosives are used differ significantly from those defined in standards. Such conditions cover, among others, the temperature of the rock mass and surroundings, humidity, rock strength parameters and the diameter of the blast holes. Consequently, the parameters of the explosives provided by the manufacturers may not correlate with those specified in-situ. Thus, within the framework of this study, the effects of the selected technological parameters on the detonation velocity of bulk emulsion explosives are presented. The analysis focused primarily on the factors directly influenced by the mine blasting services. The detonation velocity measured using the continuous wire resistance technique was used as the evaluation criterion. For this purpose, several underground in-situ tests were conducted, including the impact of the blast hole diameter, density, initiation method, sleeping time, and temperature on the detonation velocity. The results of in-situ tests have shown that the detonation velocity of bulk emulsion explosives depends strongly on the above factors, which may directly affect the effectiveness of blasting operations.

Jan 26, 2026

By William D. Hissem

For those blasthole applications which require the use of holes ranging from 1” to 5.5” in diameter, the use of top hammer drills has been the equipment of choice for several generations of drillers. Pneumatic compressed air and hydraulic compressed oil systems represent the primary technologies which are available to the drilling practitioner. While both employ the same operating principals, the characteristics of performance, cost, and reliability can be markedly different between technologies and manufacturers.

Jan 1, 1998

To meet the energy requirements, hydroelectric projects are planned and executed in many countries. Though these projects requires a high capital investment, the returns are regular with minimum maintenance after commissioning of the project and are ecofriendly. Bhutan is situated in the eastern Himalayas and covers an area of 38,394km2 (14824.01sq. miles. It is bordered by India in East, South and West and by Tibet in the North. The hydropower potential of the country is estimated at 30,000MW, out of which around 5% has been harnessed.

Jan 1, 2016

By O. Rielo, P. Katsabanis

Traditionally fine aluminum is not used in dry commercial explosives due to the hazard associated with aluminum dust explosions during mixing. An industrial process has been developed which enables the safe use of paint grade Aluminum with ANFO. The addition of fine aluminum particles resulted in increased velocity of detonation of ANFO compositions. Velocities of detonation, in 52mm (2 1/16 in.) diameter confined charges were 20% higher than velocities of detonation of straight ANFO. The detonation performance of fine grained ANFO was not benefited by Al at the diameter tested. Furthermore use of larger Al flakes resulted in decreased velocities of detonation. The results are compatible with the experience of Al addition to high explosives. Tests were also conducted using bio-diesel, finding no substantial difference in the performance of AN fuel explosive compositions which used bio-diesel.

Jan 1, 2009

By Milos Bila

The second half of 2008 and the first half of 2009 brought up important anniversaries. My old passport from Czechoslovakia has a stamp with date 10-10-1968 at 10:00 AM, the exact time I crossed the border between the former Czechoslovak Republic and Austria. This date has an important meaning because I could not come back to my country for the next 21 years. The 40th anniversary of Soviet led invasion, which took place on the 21st of August 2008, revealed some unknown and long time kept secret news.

Jan 1, 2010

By Randall M. Wheeler

Many of us have used a seismograph to measure peak particle velocity and frequency. But do we really understand why? Also, why do we measure particle velocity instead of displacement and/or acceleration? What is the vector sum? How do these items relate? Where does frequency fit in? This workshop will attempt to answer these and other questions. Some of the answers may surprise you, others may not.

Jan 1, 1997

By Derek T. Novotny

Blasting cap precision is of major importance to advanced blast design. New technologies have introduced the use of microchips within detonator casings in the hope that the electronic control of the timing element will increase the accuracy of the cap and therefore improve the results of perimeter control blasting applications. The electronic detonators have proven to be accurate in timing tests done to date. They boast cap scatter results to microsecond accuracy, but the question is, does this degree of accuracy actually prove to be beneficial during practical use in the industry, or are conventional technologies applicable.

Jan 1, 1998

By Wilfred G. Comeao

Close-in blasting occurs every time the use o f explosives for excavation or demolition requires the surpassing of the commonly accepted cosmetic damage criteriain order to arrive at reasonable and practical explosive weights per delay. One of the many effective blast design procedures consists in establishing a reasonable charge weight per delay with respect to scale, geometry, costs, requirements and constraints of the project. Once this reasonable charge weight per delay is determined, it’s environmental effects have to be estimated with respect to the surroundings.

Jan 1, 1991

By A Tawadrous, P D. Katsabanis, S Kim

A series of small scale tests, have been performed to establish the effect of powder factor and initiation timing on the grindability of rocks. The blasts were performed in high quality granite blocks, which were cut from stone prepared by dimensional stone quarry operations. Three different types of granite, Barre, Stanstead and Laurentian, were tested. The charge consisted of detonating cord placed in five holes with water as a coupling medium, or concentrated charges of equal mass of high exolosive, fully stemmed or air decked. Powder factor was varied from 0.39 to 1.17 kg/m3. Charges were detonated simultaneously or with a small delay and in some experiments, detonation waves collided in the middle of each borehole. All fragments were collected and screened, and drop weight impact tests were performed on selected size fractions, using different levels of impact energy, to calculate the resistance of the rock to impact breakage. The work index of some of the blasted samples was measured using standard Bond mill grindability tests. The experiments generally showed increased softening of the rock with powder factor, manifested by the increasing initial slope of the relationship between t10 and impact energy. The rate of change of the initial slope decreased with increasing powder factor. Changes in the work index were small and consistent in trend with the results of the single fragment impact characterization tests. Charge configuration, timing as well as in-hole collisions of detonation waves affected the initial fragmentation but had little effect on the impact breakage of the samples.

Jan 1, 2009

By John Meuth, Brandon Fryman, P. E. Hoffman, Joshua Ph. D., P. E. Calnan, Josh Ph. D.

Quantitative Risk Assessment (QRA) can be specifically tailored for use by the commercial explosives industry to calculate risk to employees and the public from commercial explosives facilities and operations. This methodology has several advantages over the American Table of Distances (ATD) which is solely a Quantity Distance (Q/D) analysis. While the ATD has remained essentially the same for 100 years, the safety of commercial explosives in storage has increased immensely. However, the concepts behind QRA calculations are not as intuitive and even at the end of the calculations the values of risk must be compared to something. A few regimes for assessing an acceptable level of risk are discussed in this paper. Risk levels for various United States Federal entities and international agencies are highlighted and suggestions for acceptable risk criteria for individuals and groups are provided. Referencing risk levels from normal daily activities is also done in this paper to make relative the accepted risk criteria. This paper presents some relevant individual risks for everyday activities and some scenarios for group risk for comparison. Individual risk is a straightforward concept however group risk is more complicated. This paper aims to clarify these concepts and provide means to communicate them to the public.

Jan 1, 2019

By Andrew Palangio, Blessing Taiwo

Understanding rock mass structural features is essential for optimizing blast design, highwall control, and evaluating post-blast performance in both surface and underground mining operations. This paper presents a comprehensive methodology utilizing image-based structural mapping to accurately characterize geological discontinuities including joints, faults, and lineations captured from both terrestrial and aerial imagery at varying scales. Key structural parameters such as joint orientation, spacing, and apparent in-situ block size are extracted to understand rock mass classification and enhance blast design inputs with greater geotechnical precision. The study introduces a significant enhancement to the existing discontinuity assessment algorithm by integrating a deep learning-assisted detection process. This improvement enables more accurate, quantitative and consistent identification of pre-existing cracks and surface features across complex bench free faces. The enhanced system facilitates better evaluation of how structural features influence blast fragmentation, energy distribution, and slope stability. A case study from a limestone quarry illustrates the use of a derived comminution factor based on the relationship between joint-controlled pre-blast block sizes and post-blast fragmentation to evaluate blast performance and optimize future design strategies. The results highlight the value of structural analysis in reducing overbreak, minimizing underbreak, and improving fragmentation predictability. This paper emphasizes the importance of integrating structural assessments into the blasting workflow to enable a more data-driven, geotechnically informed, and performance-optimized approach to modern blast design and evaluation.

Jan 26, 2026

By Randall M. Wheeler

"Fourier analysis is a very powerful frequency analysis tool. However, it is frequently misunderstood and sometimes used inappropriately. Part of this workshop will involve the basics of Fourier series, the Fourier integral and finally the Fourier transform. Included will be a brief discussion of analysiswindows, including the box and Hamring windows."

Jan 1, 1998

By Calvin Konya, Anthony Konya

State and Federal construction specifications require the Blasting Contractor to prepare a Master Blasting Plan which is reviewed by the Owner’s Representative. The Master Blasting Plan requires the Contractor to submit the design of a typical blast. Most blasting specifications also require the Blasting Contractor to submit Daily Blasting Plans. The Master Blasting Plan and the Daily Blasting Plan require that the Blasting Contractor also submit the types and quantities of explosives and initiators used. The specifications also request that the Blasting Contractor submit the pounds of explosive used per delay for both production and presplit blasts. The Blasting Contractor may also be required to predict the anticipated ground vibration and air overpressure levels for the proposed blasts. There are equations that can be used to predict the ground vibration. There are also equations that can be used to predict the air overpressure levels. The data for these equations were primarily derived from quarry and surface coal mine and some construction blasts. Data from major construction projects were analyzed in this study to determine new air overpressure propagation equations for construction blasting. These new prediction equations compare calculated results analyzed from field data with other existing air overpressure prediction equations. Production blasting air overpressure values are also compared to air overpressure from presplitting

Jan 1, 2015

By Billy Rosseau, Mike Cammack, Richard O’Meara, Gustavo Azpilcueta

During the summer of 2014, the U.S. Army Corps of Engineers (USACE) sought proposals to vastly improve and expand the small boat harbor in Valdez, Alaska. It would be a multi-year project, and construction was scheduled to begin in the spring of 2015. One aspect of the project was the construction of a 3,100 feet (1000 m) rubble-mound breakwater to protect a mooring basin. An estimated 208,500 tons (190,000 t) of rock, ranging in size from 160 to 3500 lbs (73 – 1600 kg), were needed to build the breakwater. The Glacier Point Quarry was selected as the rock source due to its proximity to the project and the quality of the rock meeting all of the USACE rock standards.

Jan 1, 2017

By C. Rutledge

The new mining method of multiple strata blasting, called StratablastTM, is described in a separate paper presented at this conference. The current paper presents three case studies where the technique was implemented in three different configurations in large-scale blasts in Australia. The first two blasts were in the Hunter Valley of NSW while the third was at Ensham Mine in Central Queensland. All blasts comprised multiple layers that were blasted in a single drill and blast cycle, with unique designs applied to each layer to achieve different blast outcomes from the various layers.

Jan 1, 2006

By Dale Preece, Stephen Chung, Qian Liu

Stoping is one of the widely adapted methods in underground mining. In this method, fanned or parallel holes are often drilled from a top sill down to a sub- level in the ore zone and blasted ring by ring into a stope for excavation. At Brunswick Mine of Canada, this technique has been used daily in conducting production blasts. However, when mining into the West Ore Zone, it has been identified strategically that a mass stope blast, involving the blasting of rock from the 3-sub level down to the 1-sub level, should be considered to ensure the safe operation and regaining of access to the trapped main ore zone. The challenge of this mass blast lies in the control of ground vibration and precise timing for blasting 800 holes drilled in six blocks from three different levels within 6.5 seconds, to allow sufficient void to be created in each level for the muck moving in order from the upper to the lower levels without bridging. This paper describes stope blast simulations using a discrete element computer code for modeling blast-induced rock displacement in conjunction with a precision electronic programmable delay timing system for various stope geometries including a drop raise blast at the start of the mass blast. The modeling concept is also described in the paper.

Jan 1, 2003

By Don McCarthy

Modern mining has been dominated by the drill-and-blast method for more than a century. There have been steady improvements in drilling technology, explosive products, methods of initiation and integration of the two techniques but the essential cyclical nature of drill-and-blast rock excavation naturally limits continuous improvements in cost and productivity. Dynamite and safety fuses, compressed-airdriven tools, and most of the crushing and grinding machinery in use today were all developed before 1900. Moreover, virtually every mechanized mining system used today was in use by the late 1950’s.

Jan 1, 1998

By Tom Palangio, Ralph M. Olmstead

Video inspection of boreholes with cameras developed specifically for the mining industry is now possible. These designs are reliable, cost effective, and have the flexibility to be used in other applications.

Jan 1, 1998