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By John Brulia

It has been said that the only thing that remains constant is change. After more than 33 years in the explosives industry, I do not take any exception to that adage. I have seen changes in people, changes in ownership of companies-both small and large, domestic and international; changes in products; changes in the way we use products; changes in the way we handle products; changes in regulations; and last, but not least, changes in our perceptions of threats to our industry.

Jan 1, 2008

By Steve Dillingham

Blasting crews, explosive product drivers, drillers, blasters, supervisors, and salespeople all arrive daily at customer blast sites in vehicles of every type whether passenger cars, pickup trucks, or bulk trucks. The majority of these vehicles are company owned and re p re s e n t a substantial investment and risk for the company. That may explain why the costs resulting from blasting incidents is often surpassed by those involving motor vehicle accidents.

Jan 1, 2003

By Elliott A. Pood, Ron Gilbert

Recent advances in digital recording technology have allowed frame rate increases in video recording equipment that provide the capability for super slow motion playback of commercial explosives shots. Such slow motion playback allows for the analysis of shot patterns, cap scatter, pattern failures, etc. In addition, the availability of such materials on video tape enables commercial blasters to provide a means for training current and future staff.

Jan 1, 1996

By James Rowland, Marcia Harris, Richard Mainiero

This paper reviews the potential hazards posed by the toxic fumes produced by detonating explosives in surface mining and construction operations. Blasting operations produce both toxic and nontoxic gaseous products; the toxic being mainly carbon monoxide (CO) and the oxides of nitrogen (NO x ). The quantity of toxic gases produced by an explosive is affected by formulation, confinement, age of the explosive, and contamination of the explosive with water or drill cuttings, among others. Techniques to protect workers and the public from the potential hazards of explosive-related toxic fumes are discussed.

Jan 1, 2007

By M S. Stern, R Aguila

To control direct blasting costs many open pit mines dewater and line wet blastholes before loading them with ANFO or Heavy ANFO blends of explosives. The plastic lay-flat tubing used for these liners can be punctured during loading and allow water to partly dissolve and desensitise the explosive column which reduces blasting performance.

Jan 1, 1997

By Gene Baker

A new Safety Library Publication (SLP), SLP-27, which is titled “Security in Manufacturing, Transportation, Storage and Use of Commercial Explosives” was recently released by the Institute of Makers of Explosives (IME). SLP-27 makes recommendations for both general security and enhanced security at explosives sites when security risk levels, declared by the Department of Homeland Security (DHS) using its Advisory System, have temporarily increased.

Jan 1, 2006

By John R. Holliday, William Marcum

Apogee Coal Company, DBA Arch of West Virginia, faced the challenge of drilling and blasting over one million cubic yards of high temperature overburden at its Ruffner surface operation near Logan, West Virginia. The overburden was removed above the Upper Five Block seam that was previously deep mined, abandoned, and later engulfed by fire. Borehole temperatures were measured above 700” F.

Jan 1, 1996

By Tianrui Xu, Chaohong Liu, Bangqing Ding

The authors were responsible for a series of large scale multiple chamber charge blasts conducted in the granite mountain area for making construction space on the southeast sea coast in China during 1993-1996. This paper describes the blast design and damage control of one mountain blast 320m in length and 280m in width in the vicinity of two wharfs and a dam. In order to obtain better rock fragmentation and muckpile, the explosive charge should be well-distributed in the mountain. The charge pattern, therefore, was designed with mainly 5 rows of tunnel charge in regular terrain in combination with a chamber charge in irregular topography area and the maximum burden was limited to be less than 38m. In order to protect the dam and wharfs the firing sequence was carefully arranged in 29 intervals and the distance between different charges of the same delay to the dam or wharf was taken into account as an additional delay interval based on the difference of p-wave propagating times. The maximum charge fired in an interval was also limited to less than 34t explosives through dividing the larger charge by a stemming deck.

Jan 1, 1998

By W. J. Birch, M. Kirke

Despite increasing competition from mechanical methods of tunnelling, the drill and blast method is often still the most viable method of excavating tunnels in strong and abrasive rock. To advance a tunnel using drill and blast, explosives are loaded into boreholes in the rock and detonated according to a prearranged sequence. On detonation of the explosive, the rock is fractured and displaced from its original position, leaving behind the desired void. Among the secondary effects of a tunnel blast are ground vibrations caused by elastic disturbances that propagate away from the blasted tunnel face. The possibility that such ground vibrations may cause permanent damage to property and substantial nuisance has generated significant opposition to the use of drill and blast, particularly in urban areas. It is therefore essential that the blasting engineer is able to predict Peak Particle Velocity (PPV) vibration levels at locations in the vicinity of the blast site. Such predictive capability enables the engineer to design blasts so as to ensure that ground vibrations can be kept within acceptable levels. The objective of this project was to analyse data obtained from the ground vibration monitoring program undertaken during the drill and blast excavation of a hard rock tunnel in Central England. Seismograph recordings of tunnel blasts contain a vast amount of information that cannot possibly be expressed using a single PPV value. The main focus of the study was to investigate whether predictive capability could be improved by using scaled distance models derived for selected PPV components relating to specific detonator timings in a given tunnel round. This study has established a method of analysis that can unlock this information for predictive purposes. By permitting the extraction of sub-event Peak Particle Velocity (PPV) values and allowing Scaled Distance (SD) models to be derived for individual period numbers or groups of period numbers, the method has the potential to vastly improve PPV prediction from tunnel blasting. The method established could also help diagnose blasting problems and help target blast design modifications, resulting in improved efficiency and excavation rates.

Jan 1, 2005

By Jack Eloranta

Optimization of blasting requires the comprehension of processes including drilling through milling. The author has previously considered the role of powder factor in relationship to downstream processing costs. Recent modeling done by Lownds provides improved prediction of fragmentation based on the distribution and level of blast energy. Many recent studies have indicated improved downstream costs due to higher powder factor. However, changes in powder factor are accompanied by changes in pattern. The purpose is to segregate the effects of higher powder factor from powder distribution. This paper will attempt to use typical Mesabi Range iron ore parameters and costs to illuminate the subject of total process optimization.

Jan 1, 2001

By Douglas A. Anderson

The US Bureau of Mines, in RI 8507, has shown that blast vibrations at low frequency are more likely to cause damage and complaints than those at higher frequency. Since that publication in 1980, the Office of Surface Mining and many state and local regulatory authorities have incorporated frequency in their regulations for acceptable ground vibration from blasting. Even when frequency is not explicitly stated in regulations, it may become an issue in hearings or in court.

Jan 1, 1992

By John Montgomery

This paper discusses the major changes to the Commissioners Rules and Regulations, Chapter 120-3-10 “Rules and Regulations for Explosives and Blasting Agents”; how the changes came about, and a summary of the status of the blasting industry in Georgia.

Jan 1, 2003

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 Jerry Wallace

Construction of a new grammar school required blasting within three meters of the existing school. Due to changes not anticipated at time of bid opening, blasting had to take place while approximately 200 children were in attendance inside the building. Blasting with children in such close proximity forced the blaster to review and revise a systematic approach to construction blasting and make changes to previous Rules of Thumb guidelines. The revised rules of thumb place Blaster-in-Charge at the top of the List. Other changes specific to the project included putting in place a blasting safety plan that included communicating the serious job hazards to teachers and students. The plan included stringent lockdown guidelines establishing school procedures for accounting for each student prior to the countdown-to-blast being implemented. Emergency communications channels were kept open so that any scheduled blast could be aborted at the last instance.

Jan 1, 2001

By Jeff Dean

As the Society celebrates its 35th year as an explosives industry association, it is clear that we are part of an industry that covers many sectors of economic activity. We are the voice of those who use, transport, store, manufacture, and dispose of commercial explosives products and others that serve the end user of explosives products. Along with other associations in this industry, we have a combined membership of hundreds of companies and tens of thousands of individuals in the U.S. and around the globe.

Jan 1, 2010

By Paul Downing

A typical day for a blasting company includes what seems to be an infinite list of tasks dealing with numbers. Whether determining the exact amount of explosives material in inventory, the number of holes in the shot, the exact distance from the blast site to the nearest exposure, or the capacity of bulk hoppers, the accuracy of numbers is key to ensuring the safety of the public, property and personnel.

Jan 1, 2008

By L. Trivino

Blast-induced damage criterion based on the peak particle velocity has worked reasonably well for estimating building damage. However, the same criterion cannot be used to estimate damage to rock and mine structures such as shaft and tunnel walls. It does not take into account the nature of seismic radiation pattern in the near-field, which is very different than what is obtained at far-off distances. To investigate this phenomenon, a systematic study has been carried out involving single-hole blasts and normal production blasts, with explosive source ranging from nearly point source charges to standard borehole sizes (6-7 m long explosive column), with charge weight varying from 0.5 kg to 30 kg. In the near-field, it is shown that, both P-wave and S-wave take a dominant position compared to the mainly surface waves measured in the far-field. These are shown to depend strongly not only on the length of the explosive column but also the way it is initiated in the borehole (i.e. direct vs. reverse initiation in the borehole) with respect to the target location. The seismic radiation patterns were recorded by high-frequency triaxial accelerometer stations grouted in the rock mass. This study describes the nature of seismic radiation in the near-field from long and short charges, the role of initiation direction and their effect on frequency with respect to sensor locations or target area of interest, and their implication in prediction of blast-induced damage in the near field.

Jan 1, 2009

By Ximing Yuan, Yongsheng Xu, Hongjie Li

A study of a static demolition agent that can be used underwater has been carried out. A new type of granulated static demolition agent with rapid reaction has been tested in several hundred experiments. It can be used conveniently and simply in the field. It demonstrates a fast reaction rate with high expansion pressures. The important characteristic of the new type of granulated static demolition agent is the ability to function underwater. It will destroy rock and the other brittle material without flyrock, vibration, shock wave, toxic gas or noise. The reaction rate can be controlled within 30-60 minutes. It is difficult to use these products when the reaction rate is less than 30 minutes and it is less efficient when the reaction rate is longer than 60 minutes. The reaction rate is slightly increased after the material is kept in storage for two years. A new type of the hydraulic device that is used to measure the expansion pressure of solid materials has been designed. The expansion pressure of the granulated static demolition agent has been tested with the device. It is shows that the expansion pressure of the granulated static demolition agent can get to 80~120MPa in 60 minutes. Also included is a discussion of the thermodynamics of the static demolition agent.

Jan 1, 2003

By Russell D. Melton, Gary A. Kanelos

A construction company performed blasting operations to break up limestone bedrock for excavation of residential basements. The owners of an existing residence located approximately 400 feet from the operation claimed that vibration damaged the structure and created foundation subsidence by lowering the moisture content of the foundation soils.

Jan 1, 1996

By Mark Abernathy

When most people think of a motor vehicle accident, the direct costs resulting from that accident, such as vehicle repair or towing charges, are generally easy to quantify. However, the indirect costs associated with an accident are often overlooked. These indirect costs can take a tremendous toll on a company in more ways than you might think.

Jan 1, 2006