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By Tyler Rockley, Cara Rosen

Blasting at a granite quarry in eastern Maryland produces elevated air blast readings that can fall into the cautionary zone for the state of Maryland environmental regulations on a semi-regular basis. When designing blast patterns in this quarry, challenging geology creates rough and uneven blast faces that can be difficult to capture with 2D laser profiling fully. Utilizing several methods known to manage high air blast results like pattern adjustments, decking, and timing changes have not achieved consistent outcomes.

Feb 1, 2020

By NA NA

Copyright © 2020 International Society of Explosives Engineers

Feb 1, 2020

By Tom Watts

Bulk Security Best Practices

Jan 1, 2006

By Tapas Kumar Mukherjee, Sujit Kumar, Sanjay Kumar Singh

This paper dwells on the epic blast conducted at Tata Steel’s captive coal mine in India and the insights drawn from it. Optimal blast design parameters had to be ascertained for operating benches (6.56 yards (6 meters) to 16.40 yards (15 meters)) where shovels and mining pay-loaders are deployed. Better fragmentation and suitable muck profile with controlled vibration levels were the pre-requisites. The landmark blast was carried out at Quarry-AB, West Bokaro on 17th March 2017. The colossal blast was done with 275 US ton (250 tonnes) of explosives poured down 1074 drill holes of 6.5 inch (165 mm) diameter. This blast is unique from the perspective of vibration control as it was conducted near local villages situated beyond 546 yards (500 meters) but within 601 yards (550 meters)) from the blast site. The entire array of preparatory activities had been successfully and impeccably executed within the same day. The optimization was achieved through meticulous coordination between TSL team, M/s Solar and M/s IEL. When a rock is blasted, numerous interactions occur among granular particles which are impacted by rock mass properties, explosives properties, blasting geometry and the detonation timings. Optimized use of resources requires a better understanding of these interactions. Extensive field studies have shown that blast fragmentation and suitable muck profile influences the performance of downstream processes in a mine. Consequently, profitability of whole mining operation can be greatly improved through optimized fragmentation. For arriving at the best blast geometry, several blasts were conducted with differing ‘burden and spacing’ design and charging pattern at various loading benches of the mine. Eventually, the largest ever blast was successfully carried out. This accomplishment is the culmination of the insights derived, confidence built, and expertise evolved through a progression of larger blasts conducted earlier (202 US tons (184 tonnes) and 143 US tons (130 tonnes) respectively) by the same team. All blast parameters were within the recommended level and no adverse impact on nearby structures was evidenced. In-the hole VOD of different explosives was determined and placement of boosters was standardized. The signature blasts were conducted to optimize the delay interval between the holes in a row and between the rows. Blasting parameters were fine-tuned in alignment with the desired fragmentation level and muck pile profile conducive to smooth and expeditious loading and hauling by mining HEMM. Rock fragmentation analyses were carried out using photo-analysis system. The insights gained from this blast would serve as the cynosure for planning and carrying out more such blasts with highly optimized parameters in the future with the intent of improving mining efficiency and productivity

Jan 1, 2019

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 John Wall

The use of electronic detonators in civil tunnelling applications, to reduce vibration is small firings has been successfully utilised for a number of years. As part of the mining industry’s commitment to reducing blast damage during the development cycle in underground mining applications, a series of development blasts using eDevTM electronic detonators in typical mining applications was conducted in North Queensland, Australia.

Jan 1, 2012

By S. S. Jenkins Jr.

While the method is seldom used anymore, coyote blasting is an historically interesting way to blast large quantities of rock. It was used extensively in the days before modern fast drills were available and can be very effective in some formations that have a natural breakage pattern. This paper will cover the general principles, some blast design factors and point out several actual blasts including some very large ones.

Jan 1, 2005

By Catherine T. Aimone-Martin, Brent Meins

Blast vibration monitoring for buried pipelines is typically conducted at the ground surface with a shallowly buried geophone. In many jurisdictions across the U.S., blast-related vibration limits set for pipelines are dictated by surface measurements and do not consider the significant reduction of PPV amplitudes acting on the pipe at depth. This study involved a vertical array of geophones deployed in drilled holes at two blasting sites of the Loop 202 South Mountain Freeway construction project in Phoenix, Arizona. City of Phoenix pipeline engineers were concerned that blasting would damage an aged 48-inch (122 cm) prestressed concrete cylinder pipe (PCCP) that serviced water for South Phoenix

Jan 1, 2019

By Paul Worsey, Matthew Coy

In the blasting industry, many different techniques are used to estimate and examine the effects of varying explosives and blast designs on the breakage of a rock mass. The overall objective is to find a cost-minimized blasting solution that also conforms to the legal and environmental concerns related to blasting. A major drawback to current blasting methods is the inability to account for "caprock," or a thick overlying layer found in sedimentary rocks that creates large amounts of oversize blasted material, especially on the top of a muck pile. This can lead to underestimating oversize in shots with massive top layers. A better fundamental understanding of blasting processes with caprock is required.

Jan 1, 2018

By Joshua Hoffman, Braden Lusk, Kyle Perry

Despite its porous and lightweight characteristics, aluminum mesh is believed to have blast mitigation properties. The current use of the mesh includes fuel tanks for airplanes, boats, and fuel stations as well as light armored vehicles for the military. The mesh acts as an explosion suppressant by preventing fuel tanks from exploding when exposed to an ignition source. More recently, work has been performed to assess the ability of the mesh to mitigate blast pressures produced by high explosives.

Jan 1, 2009

By Luiz Felipe Mendonça de Amorim, Adimir Fernando Rezende, Gustavo Sampaio Lopes, Claudio Cesar Gajardo Arraño, Eltton de Sousa Veras, Manuel Villalobos Calderon

Many technical challenges were encountered while conducting near-field construction blasting between the critical intersection of Interstate 10 and multiple active railroad tracks in El Paso, Texas, for the Loop 375 Border West Expressway Project. Blasting was utilized for the removal of an andesite bedrock ridge in preparation for the construction of a new elevated super structure to be suspended over the existing railroad tracks. There was concern that the excessive vibrations and/or permanent rock deformation produced from the blasting within near proximity (20 feet, or 6.09 meters) of the railroad tracks would induce excessive stress and foul the tracks by shifting the alignment. This could result in a major loss of scheduling control between the two major railroad companies that operate in this area. There was also concern that the blasting may cause rock fragments to land on and interfere with critical interstate transportation. Blasts

Jan 1, 2019

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 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

By L. A. Heim, E. A. McCullough, N. J. Amiotte

The explosives industry is subject to the laws of multiple jurisdictions, which means that several regulatory agencies are responsible for governing different aspects of the commercial explosives industry. Among these regulators are the Mine Safety and Health Administration (MSHA) who implements codes that better ensure both occupational and public safety which is influenced by professional blasting projects and the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), who enforces commercial explosives storage and security, among other responsibilities.

Jan 1, 2014

By Quentin L. Rhoton

"The use of explosives in a surgical manner was approved to facilitate, due to time constraints, anextremely significant paleontological find in the Plunket Point area of the Dominion Range, Antarctica. The organic material revealed by surgical blasting techniques may have altered basic scientific dogma on Antarctic glaciation theory."

Jan 1, 1999

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 Rohan Stevens, Katsuhiro Kameyama, Osamu Iwata, Jinming Liao

In densely populated cities such as Hong Kong, where unoccupied space is becoming more valuable as the population grows, city planners are more often looking to underground space to meet the increasing need for transportation and services. Given the dense population of people, amenities and high-rise buildings above or near such underground space, it is essential to minimise any disturbance and potential damage during construction. Hence, the excavation of hard rock to develop such underground space can be highly restricted, expensive and time consuming. This is the case for many of the tunnels currently being excavated by drill and blast directly underneath Hong Kong’s busiest business districts and most popular residential areas.

Jan 1, 2013

By Steve Collinsworth

Sometimes, for those of us in the right place at the right time with the right product, necessity creates opportunity. Such is my case at a West Virginia coal mine where a mine manager was desperately seeking a way to eliminate coal damage on cast shots while maintaining cast percentage without the expensive process of secondary drilling. This paper will focus on how bottom hole air decking is solving the problem.

Jan 1, 2000

By Martin Schrier

This paper is an overview of a granite quarry cleanup near Kirkland Lake, Ontario, Canada. A combination of local geology and previous subpar blasting techniques led to the quarry needing significant rehabilitation before it could proceed with general operation. Advanced technologies were implemented into the blasting process, including laser profiling, bore-hole tracking, and geometric timing. The contract consisted of two floor shots and two 25,000 tonne (27,558 US ton) production shots.

Jan 1, 2018

By Thomas L. Barkley

My historic auditing of Underground Drilling and Blasting Practices has demonstrated to the author the need for reviews of many mines' procedures in these processes. Poor understanding of the basic principles and practices of the drilling and blasting science in Underground Development Mining has created significant costs to mining operations in many instances.

Jan 1, 2019