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By Robert Hopler

THIS paper deals specifically with heading-driving as distinguished from the broader term tunnel-driving. A heading is a pilot or path-finder for the main tunnel. Some headings are complete tunnels in themselves; that is, conditions at times warrant driving a heading the full diameter of the proposed tunnel. A tunnel 10 ft. in diameter might be driven to advantage through a single heading, provided the nature of the material admits, but it usually pays to drive rock tunnels of large diameter through the headingand-bench system. Much depends upon the material, as in soft ground tunnels of much larger diameter are driven in a single heading.

Jan 1, 2010

By Randall Head

The drilling at the Taum Sauk Reservoir was a unique compilation of the latest technology and everyday common sense. This site is comprised of rhyolite, which is 30 times harder than limestone in comparison. Using some of the most state of the art drills, coupled with GPS guidance, angular drilling systems, and an ordinary piece of string, some of the most amazing drilling feats were accomplished. By constructing the new dam on top of a mountain that had been blasted once before nearly 50 years ago treacherous conditions for the drills and crew were a challenge. The drills had to be flown in by cranes to get to their locations, where they then drilled anywhere from 2.5 to 6 inch (6.4 to 15.2 cm) holes at angles up to 24.4 degrees. Custom drill bits were designed by the drilling crew to tackle feats such as drilling holes up to 120 feet (36.6 m) deep. A main challenge was the shape of the reservoir, as it is not in a straight line, but rather round, so no technological way was readily available to use to drill. Common sense came in and an ordinary piece of string was used to aide in drilling the hole. A revolutionary step was that our drill was used to core our own samples. By using our own equipment, we were able to complete this task for one-third of the cost of having a third party contractor obtain the core samples. On this unmatched jobsite, it has been established that technology has come a long way, but when all else fails, a piece of string will do just fine.

Jan 1, 2010

By David Porter, Nathan Rouse

The implementation of presplit perimeter control in underground mining as a method to decrease dilution yields positive benefits throughout the current and future mining cycles. A case study to understand the benefits of reducing overbreak and underbreak in a cut and fill mining cycle was performed to quantify the reduction in backbreak. The study was performed in a control section of the mine where a presplit perimeter control design was utilized for a length of heading. This control heading was then compared to the existing standard blasting design within the same mining zone. The comparison included multiple aspects of the mining advance including overbreak, dilution of waste, dilution of Cemented Rock Fill, bolt counts, and cycle times. Once mining in the control section was completed and mining commenced in adjacent headings, blast damage due to blast design could be quantified.

Feb 6, 2023

By Natalie Zeleznik, Brian Hawkins, David Bradley, Rachel Gooding, Patrick Wilson, Brian Somes

"To perform a probabilistic risk assessment (PRA), a method of quantifying the risks associated withinfrequent, high consequence events, consequence models that generate representative estimates of human health consequences for a wide variety of representative scenarios are commonly used. Criteria that suitable models must possess include: (1) input requirements necessary to generate large volumes ofprobabilistic simulations; (2) the capability to output injuries with the necessary details and resolution;(3) the ability to capture the variety of different scenarios inherent in an assessment; (4) acceptablecomputational requirements; and (5) sufficient stakeholder buy-in for community acceptance."

Jan 1, 2017

By Clara Godoy, Paulo Couceiro, Juan Navarro

The continuous automatization and digitalization of the different stages involved in any underground construction bring new possibilities to optimize the operation. One of the most important requirements for the development of these projects consist of a proper rock mass characterization for optimizing the stages of the drilling, blasting and support cycle. In the last few years the road to digitalization has gone through data science and big data, showing the importance of data gathered to describe the geological and geotechnical environment that surrounds the operations. Since rock characteristics have an important influence in the drilling response, the technological advances in the sensorization of drilling machinery such as the Measurement While Drilling system (MWD) allow to gather the necessary amount of information to be applied in data science processes to evaluate changes in the rock mass with higher resolution than conventional methods. In this paper, Machine Learning techniques have been used to combine data monitored from the drill rigwith scanner profiles of the excavated sections to develop an automatic geotechnical rock mass characterization model able to estimate potential zones of over- or under-break of the remaining rock mass in underground blasting. By comparison of scanner profiles of the excavated sections with the blasthole positions, an Excavated Mean Distance (EMD) between the contour blastholes and the excavated profile has been obtained, which may be considered as damage measure. Considering blasting factors as constant, the model combines the rotary, percussive, hydraulic flushing and the rate of advance of the drilling, and the confinement of the rock mass by depth, to detect zones with different rock properties. This provide an early information of the rock mass condition around the blastholes and the prediction of expected overbreak generated after blasting, being possible to design more efficient bastings, in which each borehole is filled with the right and necessary explosive charge. The analysis comprises data from 57 blasts (around 1700 contour blastholes) and more than 4000 excavated sections.

By David Leidel

A revolution in hydrocarbon well completions within the last thirty years has enabled drillers to tap the resources of known gas plays in an economically viable manner and deliver to market natural gas supplies for industrial, transportation and domestic use without the importation of liquefied natural gas from verseas. An added benefit has been the convenient location of one of these gas plays, the Marcellus Shale, in the Northeastern states strategically close to a major natural gas market, namely the cities and towns of the New England and Mid-Atlantic states. As a sidelight, the development of the tight gas reservoirs and their subsequent production has created thousands of jobs in an otherwise lackluster economy.

Jan 1, 2014

By Clara Godoy, J. A. Sanchidrian

In this paper, Machine Learning techniques have been used to combine data monitored from the drill rig with scanner profiles of the excavated sections to develop an automatic geotechnical rock mass characterization model able to estimate potential zones of over- or under-break of the remaining rock mass in underground blasting. By comparison of scanner profiles of the excavated sections with the blasthole positions, an Excavated Mean Distance (EMD) between the contour blastholes and the excavated profile has been obtained, which may be considered as damage measure.

Feb 1, 2020

By Paulo Couceiro, Manuel Lopez Cano

"The Panama Canal is one of the most important engineering projects of the modern era and plays astrategic role in the global economy and international maritime trade since its inauguration in 1914. Now, a little more than one century later, the final phase of its expansion program, the largest infrastructure works undertaken since its inauguration, has concluded. This expansion program has created a new lane of traffic along the Canal with the construction of a new set of locks – one on the Pacific side and another one on the Atlantic side -, increasing the Canal’s capacity and its impact on the world’s economy even more."

Jan 1, 2017

By Neal Lee

Often the effects of wet boreholes are not taken into consideration when designing a blasting program to exhibit a certain amount of explosive energy per unit of rock such as design by powder factor, expressed in lbs./bcy (pounds explosives per bank cubic yard) or kg/bcm (kilograms per cubic meter), often the effects of wet holes are not considered. This paper examines different methods of loading wet holes and the effects they have on actual explosive quantities/unit of rock. In particular, we are looking at the amount of water trapped within the explosive column (bulk loading from the collar), or the annular space left void of explosives product around and between cartridges (wet-bags) with many of the current wet hole loading methods in use. We will focus on the effect this has on actual powder factor relative to “as designed” dry hole loading values, as well as the effect on performance of the explosives.

Jan 1, 2011

By D. Lee Petersen, Travis Davidsavor

The 2003-2004 expansion of a Duluth medical center required rock blasting adjacent to the existing structures, a Mn/DOT retaining wall and other urban structures. This case history describes the methods of a blast damage assessment, based on blast parameters, excavation locations, and critical vibration receptors (including surgical suites, a linear accelerator and a major retaining wall). The assessment concluded that blast vibrations could be controlled, by limiting charge weight, to eliminate impact at the critical receptors. Prior to construction, we conducted preconstruction surveys on structures susceptible to vibration damage. During construction, we reviewed submittals, observed test blasts, reviewed blasting logs and monitored blasting vibrations. Up to 13 seismographs were used simultaneously. Close coordination with medical center operations personnel was necessary to prevent impacts to critical medical procedures. Measured vibrations were clustered around the predicted values, and attenuated at the predicted rate. High-frequency blast induced ground vibrations induced low-frequency vibration of an adjacent MnDOT retaining wall. Medical center structures were observed to significantly attenuate the ground-borne vibrations. This paper was first published in the Proceedings of the 56th Annual Geotechnical Engineering Conference, 2008, at the University of Minnesota.

Jan 1, 2010

By Travis A. Davidson, Ralph E. Burnham, Cathy Aimone-Martin, J. Kelly Ratliff

Blasters face a long list of tasks to execute daily—from vehicle inspections to blast design and layout, hole loading and tie-in, securing the site, and finally, safely executing the blast. Good practices and, in most cases, regulations and requirements necessitate documenting their work, specifically their blast report. While some blasters use paper forms, others use electronic means to streamline the process. The authors have served as attorneys and expert witnesses in representing companies and individual blasters in numerous administrative and legal matters in which documentation of the blaster’s work was both critical and detrimental to the effectiveness of defending their work. This paper discusses in a case-study manner the authors' observations concerning good blast report format, specific observations around electronic and paper report completion, record-keeping, seismograph setup and recordkeeping, video and photo documentation, internal auditing, and other topics related to documenting the blast. The paper aims to serve as a discussion guide for blasters to improve their blast record-keeping process, develop better practices that effectively document their work, and allow them to defend their work should a claim arise concerning their operations.

Jan 21, 2025

By Tom Short, Bill Beam

Some of the weapons testing shafts at Mercury, Nevada require depths of 1000ft and diameters of 10 feet. The top 40 feet to 65 feet is drilled, blasted and excavated by Large caisson type augers in order to provide vertical working room for the placement of large, oil field type, drilling rigs and the required drill collar.

Jan 1, 1991

By Kerina Taylor

Due to their high amount of stored energy, explosives have been the cause of many serious injuries and fatalities over the last centuries. Despite safety advances and awareness in the last decades, injuries and fatalities continue to occur at mining operations due to blasting. According to the National Institute for Occupational Safety and Health, from 1978 to 2001, blasting incidents claimed 106 lives and were responsible for over 1000 injuries in mines in the US. The main causes of incidents found today are flyrock, blast area security and premature detonations. The concerted efforts of the mining and explosives industries and labour and government agencies have greatly improved the safety record of blasting in mines.

Jan 1, 2011

By J S. Brower

Disposing of the AMDP-1, Jackup drilling rig in the Arabian Gulf.

Jan 1, 1978

By Joe Atalla, Jesse Desrochers, Rodrigo Hayashida, Joseph Mukendi Kabuya

The Mont-Wright mine stands as a prominent open-pit operation in Canada, renowned for its vast iron-ore reserves. However, the efficacy of its blasting operations, crucial for efficient production, has encountered challenges due to the diverse lithological compositions across multiple pits. This study presents a comprehensive approach to optimize blasting practices at Mont-Wright mine, tailored to the specific lithological characteristics of each rock domain. Through systematic analysis and experimentation, blasting guidelines were meticulously developed, aiming to enhance grindability and equipment productivity. The implementation of these guidelines promises significant improvements in operational efficiency and resource utilization, positioning Mont-Wright mine at the forefront of sustainable iron-ore extraction.

Jan 21, 2025

By G. R. Adhikari

A major part of mineral production comes from surface mining and there has been a rapid growth in this sector with the deployment of high capacity equipment. The importance of blast design combining appropriately both theoretical methods and practical approach has been well recognized in the field of surface mining. It is known that blast design has a direct consequence on productivity, safety and economic viability of these mines. Blasting is the most common method of breaking rocks in mining, but it has to be cost-effective. In coal production, for instance, drilling and blasting account for 25 percent of the total procution cost. In hard rock mining, the cost of drilling and blasting is about 40 percent. Due to ever increasing concern for cost-effectiveness together with environmental consciousness, designing blasts for each application has now become a stringent requirement and indeed a challenging task as well.

Jan 1, 2002

By DuPont Magazine

RBH Note: as stated many times in these articles, frozen dynamite was one of the greatest hazards facing the blaster. It wasn’t until the late 1920s that it was solved for good, with the introduction of nitrated ethylene glycol as a partial replacement for nitroglycerin in dynamites. The du Pont low freezing dynamites contained TNT, DNT, or nitro-substitution compounds of various sorts.

Jan 1, 2015

By Daniel Scott

Mines have used explosives for economical fragmentation for many years. It can therefore be expected that the mining industry has thoroughly researched how to achieve the most efficient blast. However, there is still a large amount of iteration that must be undertaken before blasting at a mine site can be refined enough to allow for consecutively successful blast results. And then the geology changes. This paper will present an approach to blast design that considers production goals, geology, budget, and safety, and will contrast the proposed method with well established blasting theory.

Jan 1, 2012

By Paul Klaric, Nicholas Bodley

Every blasting engineer or professional can attest to the age-old conundrum of obtaining accurate hole information on a large scale prior to loading explosive charges in a blast hole. Even though the benefits of QA/QC are well known and documented and are becoming increasingly important when digitizing and automating mining operations, the QA/QC process itself has not changed significantly over generations. The current methods where operators deploy measuring tapes of variable standards recording their subjective assessment of hole length on a paper blast map or manually transcribing to a tablet, are unreliable and non-auditable. Additionally, the process in its current form is time intensive, obtaining only moderate results and benefits, making it difficult or impossible to resource in today’s tight labour markets. Often only two data points, depth, and water presence, are captured when visiting the hole resulting in a high cost per bit of data. For these reasons, the process is seldom done on a large scale, let alone integrated. The QA/QC process in its current shape is a gap that will need to be addressed if autonomous blasting and mining is to become a reality.

Feb 6, 2023

Controlled Blasting, Inc. (CBI) located in Norcross, Georgia recently teamed with the Dekalb county fire marshals office to stage a mock disaster to test new trainees of Community Emergency Response Team (CERT). It as an interesting example in which industry can help out the community and government through the use of explosives.

Jan 1, 2010