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By Robert Hopler

GEO. M. MOWBRAY’S REFRIGERATOR CAR FOR THE SAFE CONVEYANCE OF EXPLOSIVES. It is a fact well known to all miners who have used nitro-glycerin, or any of its adulterations, commonly known as dynamite, rendrock, Hercules’ powder, dualin, vigorite, etc., that when congealed, these compounds cannot be exploded, and in this congealed state — say at temperatures below 40° F. — they can be handled with no more danger than a box of soap or a can of lard. If, then, the atmosphere by which this class of explosives is surrounded, during transportation, be maintained below 40° F., explosion is practically annihilated. Therefore, I constructed a refrigerator car, with cells for every box of the explosive; and two years of railroad transportation confirms our ten years’ experience in teaming in wagons, that this class of explosives can be transported in perfect safety, as above described.

Jan 1, 2011

By Catherine T. Aimone-Martin, Kristen Kolden

In August of 2013 the USDA Forest Service (USFS) blasted bedrock at the base of a waterfall in Kanalku Creek within the Kootznoowoo Wilderness Area on Admiralty Island in the Tongass National Forest located in Southeast Alaska. The purpose of the blasting was to widen and deepen a plunge pool at the base of a waterfall complex considered to be a partial barrier to migrating sockeye salmon. Drilling and blasting to remove 12 to 15 cubic yards of rock occurred over a two day period.

Jan 1, 2015

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 Hae-Moon Choi, Sang-Don Lee, Hee Soon Shin, Choon Sunwo, Chang-Ha Ryu, Hyun-Koo Lee

Building tunnels means dealing with what rock is encountered. Relocation of the site of the underground structure is rarely possible. Tunneling engineers and miners have to cope with the quality of the rock mass as it is. Different tunneling philosophies and different rock classification methods have been developed in various countries. Most of the rock classification methods are based on the response of the rock mass to the excavation. Tunnel support requirements could be assessed analytically, supplemented by rock mass classification predictions, and verified by measurements during construction. Rock mass classifications on their own should only be used for preliminary, planning purposes and not for final tunnel support. Design of blast pattern in tunneling projects in Korea is also for the most part prepared according to the general rock classification methods such as RMR or Q. It, however, does not take into account the blast performance, and as a consequence, produce poor blasting results. In this paper, the methods of general rock classification and blast design for tunnel excavation in Korea are reviewed, and efforts to develop a new classification method, reflecting the blasting performance, are presented. Copyright ©

Jan 1, 2004

By Y Wada, Y Ogata, T Nishida

"Shaped charge is used for blast demolition of steel construction in general. It is important tocontrol movement of cutting part with shaped charge for the blast demolition of steel construction.Movement of cutting part was studied in the small scale experiment with steel bar. A numericalsimulation using the Discontinuous Deformation Analysis (DDA) was carried out. The DDAmethod was applied to the full scale blast demolition of steel construction. Results of thesenumerical simulation was compared with the blasting demolition work of steel tower."

Jan 1, 1999

By Clay McNail, Paul N. Worsey, John Schillie

"This paper is the result of undergraduate student research over the period of 2 semesters at UMR, which was focussed on developing a practical way to pneumatically stem horizontal boreholes, mostcommonly used underground. The majority of dry horizontal underground boreholes are pneumatically loaded with bulk ANFO. ANFO is preferred due to its low cost and the ease of pneumatic loading. However, stemming underground in the United States is a rare practice. In sharp contrast, stemming material (crushed stone or drill cuttings) is virtually always used in surface holes. The purpose of stemming is to increase blast efficiency by containing the explosive energy in the ground and to reduce environmental effects such as air-blast. The problem with stemming horizontal boreholes are; gravity cannot be used to load stemming material and the ANFO does not have a good interface due to problems with withdrawing the hose and the loading itself. This work follows on from Wilkins’ work on stemming angled boreholes."

Jan 1, 1999

By R. F. Favreau, Patrice Favreau

In many quarries and construction sites visited by the authors over the last 50 years, the latter have observed muck piles from blasting with explosives, which included numerous large blocks, in some cases of dimensions larger than the input to the crusher. The names of these sites cannot be given in the article because the owners insist that data obtained on such visits be kept confidential. Often the blasters felt that the natural fissures in the rock would compensate for the use of a low powder factor, and they asked the authors to explain why such blocks were present. A detailed analysis of the situation often indicated that the cause of the blocks is that explained by figures such as 6 and 7 below in the article.

Jan 1, 2018

By Braden Schmidt

The following full paper will go into the products, techniques and people who work in the avalanche control industry giving insight to the other members of the ISEE an overview of the niche blasting that is Avalanche Control.

Feb 1, 2020

By A T. Spathis

Corrections are given for “A three parameter rock fragmentation distribution” by A.T. Spathis (Measurement and Analysis of Blast Fragmentation, Workshop hosted by 10th International Symposium on Rock Fragmentation by Blasting, New Delhi, India, November 25-29, 2012 pp. 73-86). Typographical errors in two equations for the uniformity index in the two versions of the original and modified Kuz-Ram model are corrected. It is noted that the modified equation in the original published paper of Cunningham also had the same typographical error. A corrected plot of the dependence of the uniformity index versus the burden to diameter ratio is given. These corrections do not affect the rest of the original published paper.

Jan 1, 2013

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 James C. Irvine

Meramec Mining Company's Pea Ridge underground mine is presently involved in a large scale pillar recovery program and has made use of both rotary and down-the-hole drills for large diameter blastholes. Groups of pillars have been blasted with water gels in massive blasts which have broken in excess of one million tons of ore per blast. An outgrowth of the pillar recovery program is the combination of rotary and down-the-hole drills to develop vertical "raises" between mine levels. This paper outlines the Pea Ridge procedure for pillar blasting including the use of non-electric caps. Techniques and loading rates are discussed, and safeguards against blasting damage which were developed as a result of the program are presented.

Jan 1, 1976

By G Alan Foster

Many complaints generated from blasting operations result from the marked human response to ground transmitted vibrations and air blast effects and so many authorities have considered the regulation of blasting in terms of human response rather than, as previously, in terms of preventing damage to structures.

Jan 1, 1981

By D. Swanson

Cold Detonation Physics (CDP) is a patented new field of explosives and the name for the explosive that is produced when non-toxic dry ice (frozen carbon dioxide) is combined with powdered metals such as magnesium and aluminum, which are non-toxic and nitrogen-free. The explosive is detonator-sensitive and detonates according to the rapid reduction of carbon dioxide back to carbon, which produces solids comprised mainly of metal oxides and about 5% carbon. CDP was determined to produce a maximum of 300 liters of carbon dioxide per kilogram (4.81 ft3 /lb) and about 1.5 liters of carbon monoxide per kilogram (0.024 ft3 /lb). Both these figures shift according to metal content where higher metal produces less gases. According to theoretical modelling, the relationship between static pressure and metal content was determined to be an inverse parabolic curve with optimum pressure at 25% to 31% metal, depending on the type/s of metal/s used. Velocity of Detonation (VOD) was determined by measuring light at the wavefront with fiber-optic cable inserted into a series of holes drilled into the side of a 3-inch diameter (76 mm) schedule 40 steel pipe containing the mixture. The highest VOD was observed at 25% magnesium and measured between 2,500 to 4,500 m/s (8202 to 14,764 ft/s) when initiated by a 454-gram (1-pound) booster and an electric detonator. A 25% 50:50 alloy of magnesium and aluminum sample shot at a higher velocity than magnesium, according to how the alloy generated smaller pieces of shrapnel when compared with shrapnel from a magnesium test. CDP, using 25% alloy, was tested for blasting limestone by drilling 3.5-inch holes (89 mm) and inserting a 3-inch x 4-foot cardboard tube (76 mm x 1.22 m) with the mixture, packed to a density of 0.62 g/cm3 . The blast was initiated with an electric detonator, behaved like ANFO with more energy and fractured rock sufficiently across the entire length of the borehole. Seismic analysis determined that CDP produces lower ground vibrations than traditional explosives.

Jan 1, 2024

By Thomas Barkley

Until the recent past, blasters have provided good to excellent results with tools and processes that have an inherent error. These errors can be found in drilling, explosives delivery quality and consistency, explosives loading consistency, actual explosives performance, and pyrotechnic detonator initiator accuracy. My experience and data from several decades in the industry show the error is often times 10% or higher larger in the dimensions that measure the performance of each of these tools and processes.

Jan 1, 2011

By Matthew Hirsch, Jason Connot, Nathan Rouse, Srivatsan Jayaraman, Akash Adhikari, Brent Meins, Purushotham Tukkaraja

The Deep Underground Neutrino Experiment (DUNE) is a world-class particle physics research project currently being constructed 4,850 ft, 1,478 m underground at the Sanford Underground Research Facility (SURF), former site of the historic Homestake Gold Mine in Lead, SD. Construction for the project involves drill and blast excavation of 800,000 tons of rock to house neutrino detecting cryostats adjacent to on-going particle research and sensitive lab areas. To protect nearby labs during the planned 4 years of blasting operations, project specs required installation of six steel, heavily reinforced blast doors designed to withstand 20 psi blast loads. This research aimed to quantify the pressure reduction across the blast doors and more accurately model underground blast wave propagation. 827 blasts to date have been monitored at eight locations on the 4850 level of SURF with some locations behind blast doors and some in front. Additionally, pressure measurements directly in front of and behind one blast door were taken during 94 blasts.

Feb 6, 2023

By Sharkey Bowers

This study was undertaken in order to determine a conservative estimate of the attenuation rate of vibrations through the shallow limestone in South Florida due quarry blasting. The natural limestone bedrock in occurs at or near the surface in southeastern peninsular Florida. While the shallow overburden soils is advantageous for mining purposes, vibrations from blasting has been a contentious issue in South Florida due to the proximity of the mines to several residential communities. White Rock Quarries and Krome Quarries are two active mining facilities in South Florida which generate numerous complaints, insurance claims, and lawsuits from residents in nearby communities who claim that the vibrations cause damage to their houses. Both quarries are located on the eastern edge of the Everglades, with thousands of nearby residences at the western edge of development in Broward and Miami-Dade Counties. Data obtained from over 400 publicly available blast monitoring and associated seismograph reports from White Rock Quarries were reviewed and compiled. The data was used to emperically develop a conservative estimate of the ground attenuation rate based on the scaled distance from the blast origin, which can be compared to Figure B-1 from USBM RI 8507 to determine whether it is feasible if damage could have occurred at a given property.

By Derek Morris, Vito Saccheri

In the monitoring of seismic exploration (whether by explosive or vibratory energy sources), the intensity of shaking at neighboring structures can now be measured quite accurately and comprehensively with portable equipment. However, the interpretation of the results is open to considerable debate and mis-interpretation. One conventional approach is simply to compare the maximum measured peak particle velocity (PPV) with a permissible standard – usually 0.5 inches/sec (1.3 cm/sec) because this is the value generally referred to in the U.S. Bureau of Mines standard. This can be very conservative, both for surface structures, and especially for buried structures like pipes, for which absolute reliance on PPV obscures the true complexity of field problems. Quite apart from the fact that the full Bureau of Mines standard is actually a reasonably complex function of frequency (for the simple reason that in differing parts of the frequency spectrum, damage may be displacement or acceleration controlled), the effects of spatial direction and orientation are often ignored.

Jan 1, 2009

By C. Breeds, K. Jeremiah, E. Jennings

Washington State has a well developed set of blasting regulations which have been promulgated by the Department of Labor using extensive stakeholder input, not only from citizens but also from manufacturers and representatives of IME, blasters in charge, blasting engineers, blasting companies, local and federal law enforcement agencies, fire officials, and local and state government representatives. WAC 296-52 therefore provides a foundation or platform for developing city ordinances for Washington State cities should a City wish to do so. On the other hand, Oregon’s code is based on OSHA 1926, Subdivision U, Blasting and the Use of Explosives which provides scant direction regarding the modern use of explosives. Reference is also made to ODOT Section 00335 - Blasting Methods and Protection of Excavation Backslopes. This paper examines two separate programs that have been developed by two Cities, one in Washington State and one in Oregon to further regulate blasting inside City limits and discusses why the lack of a regulatory foundation made one approach more difficult than the other. One of the authors was retained by the City of Kennewick, WA to develop their ordinance and has more recently followed and reacted to a pending ordinance for the City of Redmond, Oregon. The paper will compare and contrast the different approaches and comment on the reaction from both Blasters and the public. We also present a case study that involved blasting in an urban area of Oregon to prepare a foundation for a water tank. Controlled Blasting was carried out within 70-ft of residencies and within a community that had expressed reservations regarding blasting even though the work would make a significant contribution to the betterment of the community. Pre-construction surveys of residencies located in a large area surrounding the site were performed and a well-planned blasting program was carried out. Residencies were subject to vibration levels that were monitored using six seismographs that surrounded the site and these units measured vibration levels that were significantly lower than allowed by statute. There were complaints triggered by individuals reactions to blast vibrations which validated commonly held models of human perception but no damage was caused by the Blasting.

Jan 1, 2024

By Guillermo Lazcano Ríos, Jorge Parvez Aguirre, Alejandro G. Díaz Berríos, Felipe Rodriguez Alveal

Codelco's Chuquicamata Underground Division (DCHS) faces issues due to collapses in its subsidence streets, which hinders the advancement of the subsidence front and leads to the loss of areas and reserves. To address these issues, DCHS and Orica have developed a new excavation methodology based on pre-loading explosives in high drawbell. This methodology involves creating a high drawbell extending from the floor of the production level to the ceiling of the subsidence level, divided into two phases: upper and lower. A resin stemming is used to separate these phases. The excavation strategy adjusts to variables such as reception volume, fluffing, and excavation geometry, involving vertical pre-loading of the explosive and the use of a separating element between the phases. The test aims to validate the new excavation methodology and the retaining element in the rock mass, evaluating aspects such as drawbell geometry, impact on the rock mass, damage to the retaining element, and fragmentation. Wireless electronic detonators are used in the upper phase to improve safety by eliminating the need for physical connections, while traditional electronic detonators are employed in the lower phase. Low-density bulk emulsion is applied to minimize the impact on the Crown pillar and extraction point, and higher-density explosives are used above the subsidence level to ensure good caving. Results showed that the blast achieved 86% conformity with the theoretical design. Resin stemming allowed for 100% effective detonation in the upper columns, and the fragmentation obtained was 5.44 inches, which was less than expected. No damage to the Crown pillar was observed, and the explosive quality met standards. This technique has proven to be effective and viable, suggesting the possibility of eliminating the subsidence level in future levels, resulting in savings, and providing greater stability to the rock mass.

Jan 21, 2025

By Juan Pablo Guevara, Victor Munoz, Rob Bush, Gonzalo Marias

Cerro Negro Mine, property of Goldcorp Inc., is in the process of developing four separate underground access ramps for the exploitation of high grade, narrow vein gold deposits with vertical to sub-vertical dips. The Mariana Central, Mariana Norte, and San Marcos accesses are primarily in the development stages, while the Eureka access began production stope blasting in April of 2013. Mariana Central will also begin production in May or June of 2014.

Jan 1, 2015