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By Ali Kahriman, Abdulkadir Karadogan, Umit Ozer, Mehmet Aksoy, Kagan Ozdemir, Adiguzel Deniz

This paper presents the results of ground vibration measurements induced by blasting during the construction of the Istanbul Kadiköy-Kartal metro tunnel which has been driven at a depth of approximately 20-40 m deep under a highly urbanized region of Istanbul city in Turkey. This tunnel is being constructed by a joint venture group. The formation encountered during the construction is classified as hard and strong rock by laboratory and field tests performed by the joint venture group. Within the scope of the study, for the prediction of the peak particle velocity and to determine the slope of the attenuation curves together with the maximum charge per delay for the S4 shaft tunnels and S12 shaft tunnels of this tunnel route, ground vibration components were measured carefully by using four vibration monitors (Instantel Minimate Plus model) during the advancement of the tunnels which required blasting. The particle velocities and frequency values of all blast events are evaluated according to the United States Bureau of Mines (USBM) and German DIN 4150 Norms in order to predict, and compare the influence grades to the neighbouring buildings, and structures. Also, data pairs of scaled distance and peak particle velocity obtained from 114 records at S4 shaft tunnels and 79 records at S12 shaft tunnels were analysed statistically. Empirical relationships with correlation at the 95 % confidence interval were established for different rock units (diabase and arkose) and suggested for the test sites in order to estimate particle velocity of the ground vibrations.

Jan 1, 2007

By Gungor Tuncer, Ali Kahriman, Abdulkadir Karadogan, Umit Ozer, Kagan Ozdemir

In the condition that drilling and blasting technique is inevitable depending on the rock mass and material characteristics on mining activities, the fragmentation rate and particle size distribution of the muckpile after blasting has important influences on the performance of subsequent mining activities such as loading, hauling, crushing, grinding etc. and the total costs of that mine. Drilling and blasting is an important step in this process chain and it's results such as fragmentation, muckpile shape and looseness, dilution, damage and rock softening effect the efficiency of downstream processes. There is an increasing body of blasting research indicating significant impacts in these downstream processes.

Jan 1, 2007

By Robert McClure, Frederic Leclercq, Ricardo Chavez

With significant vibration control and fragmentation challenges facing them, the CBS quarry (department of the Nord) successfully integrated a technical partner and mine to mill optimisation to deal with a difficult environment. For the last three years, CBS has been conducting a global production monitoring program similar to the mine to mill concept used in the mining industry. This concept consists of optimising the drilling and blasting while monitoring the effects on the downstream chain (vibration control, loading, hauling, crushing, plant output). Blast optimization is ensured by systematic control of the blast geometry (volumes, patterns, bench and face anomalies, drill deviation) and by the use of constant specific energy blasting. Constant specific energy optimises the work of the explosive in a blasting operation and, when combined with a high accuracy programmable electronic blasting system, reduces the impact of blasting on the environment and enhances blast performance. These techniques ensure consistent blasting results and hence improved site productivity. The improvements achieved have been identified thanks to an effective system designed to monitor the key production parameters.

Jan 1, 2007

By Robert Hopler

In part four, the instrumentation used to detect the vibrations from the 1876 Hell Gate (East River, New York) reef-clearing blast was discussed. The apparatus consisted of cups of mercury and microscopes or other magnifying instruments to detect ripples or waves on the surface of the liquid metal.

Jan 1, 2007

By Robert Hopler

Although electrical instruments were being widely introduced into the study of seismic tremors, attempts to understand and quantify shocks from blasting continued to use rather primitive methods well into the 19th century.

Jan 1, 2007

By Terri Jordan, Kenneth Hollingshead, Mary Jo Barkaszi

The Port of Miami, Miami-Dade County, Florida (Port) is the largest container port in the State of Florida. However, it is located in the center of a diverse ecosystem. Biscayne Bay surrounds the Port and portions of the bay have been designated as a National Park, a Florida Aquatic Preserve and a state Critical Wildlife Area. The bay is home to many protected, threatened and endangered species including the Florida manatee, five sea turtle species, American crocodile and bottlenose dolphin, in addition to important recreational and commercial fish species.

Jan 1, 2007

By Robert Hopler

It is the nature of the initial detonation to the powder around the cap which governs the greater or less effect of the explosion of the whole charge. The cap communicates to the first particles of powder a disruptive impulse, which, according to the nature and strength of the cap, more or less completely overthrows their equilibrium and decomposes the powder with great energy, setting up sympathetic vibrations that explode the particles of powder in turn by the violent disturbances or friction between them in a regular succession of impulses and decompositions, which, if started with sufficient energy, are of such intense heat and velocity that the rupturing force of the explosive is developed practically instantaneously. This detonation has already been shown to be not only the result of mechanical force, but a combination of extremely sudden chemical and dynamical reactions which set up vibrations to which different powders are more or less susceptible, and these explosive reactions will be propagated through the mass of the powder according to the intensity of the vibrations and the resistance with which their motion is opposed by the nature and consistency of the powder, whether it be difficult or easy to oxidize, soft and plastic like dynamite, or hard. If the initial detonation of the powder surrounding the cap is of the highest degree, the vibrations will be most intense and will be propagated further through the mass than by a poorer detonation. Hence the different degrees of detonation. Unless the first particles of powder are so thoroughly decomposed by a detonation of high order, or first degree, as to convey the necessary heat and energy to detonate the whole charge, the greatest force of the powder will not be developed. There will frequently be unbottomed holes or pieces of unexploded powder scattered about, or both, and the air in the mine will be contaminated with some obnoxious gases that have not been completely oxidized.

Jan 1, 2007

By Rudi Toba

Several areas at the DOZ haulage were observed for the crusher’s location. Initially the new crusher designed position was west of the crusher 1, but due to concerns of the mine crack zone (deep MLZ) the crusher position moved to the south. The new crusher location is situated in a diorite rock massive between 3053 – 3079 levels, with the overall excavation of 2500 cum and dimension of 14m long, 14 m wide and 14 m high. Main Crusher chamber itself excavated by development jumbo in three lifts. Development of access to the bottom crusher was developing the same time as chambering the top crusher. The pocket of the crusher mined with vertical crater retreat system which is initiated in one time after middle slot raise. Collaboration between production and perimeter blast holes to be obtaining in control the actual cuts as per the design shape.

Jan 1, 2007

Explosive manufacture, handling and transportation is hazardous and special precautions should be taken while manufacture, handling and transportation. Various regulations and rules defined in explosive act and factories act of India are discussed in this communication. General process control measures during the manufacturing of different types of explosives are also dealt in detail. Various processes hazardous in manufacture of various explosives like slurry explosives, PETN, detonators, styphnic acid, lead azide and lead styphnate and special precautions to be taken during the manufacture of the above explosives are also discussed.

Jan 1, 2007

By Theirry Bernard

The era of non-electric systems as an initiating system has revolutionised the blasting world by introducing a very safe initiating system that is reliable, with initiation sequence possibilities that are superior to those of purely pyrotechnical or electric systems. Electronic initiation has brought with it accuracy, programming and controls that were lacking in the non-electric systems. However, it has also led to a certain degree of complexity, which works against user-friendliness, sometimes introducing a few constraints that are balancing out the intrinsic performance of electronic detonators. The introduction of a hybrid initiation system, Electronic and Non Electric, offers accuracy, and flexibility that were lacking in non-electric systems, whilst removing the inherent complexity of electronic systems. This paper endeavours to summarise the advantages and disadvantages of non-electric and electronic initiation systems that have been recorded after years of experience on site. The paper will then describe how a hybrid system only keeps the advantages whilst eradicating the disadvantages, via a case study.

Jan 1, 2007

By Fumihiko Sumiya, Hideki Hamashima, Shigeru Itoh, Shinya Tanaka

The detonation characteristics of non-ideal explosives, especially the emulsion explosives, are critically affected by the confinement of case. In this study, we focused the shock wave propagating in case as confinement factor. Therefore, the objective of this study was to obtain a better understanding of the influence of shock wave propagating in case on the detonation characteristics of explosives in laboratory scale.

Jan 1, 2007

By Lon Santis, David Leidel, John Tatom, Meredith Hardwick

This paper describes the development and methodology of the Institute of Makers of Explosives’ Safety Analysis for Risk (IMESAFR), a risk analysis software program for commercial explosives operations. IME is a nonprofit safety and security association devoted to the safe and secure manufacture, transportation, storage, and use or disposal of commercial explosives in the US and Canada since 1913. The software methodology’s basis is the U.S. Department of Defense Risk Based Explosives Safety Criteria Team’s Safety Assessment for Explosives Risk (SAFER) software. A diverse group of industry and government experts contributed to modifications to SAFER that reflect commercial operations. IMESAFR is intended to supplement the American Table of Distances (ATD) and offer standardized methods of managing risk from a wide variety of commercial explosives operations where the ATD does not apply. The modifications made to SAFER primarily involved the addition of commercial activities and potential explosives sites (PES). A review of commercial explosives accidents and operations over the last 20 years served as the basis for establishing probability of event values. An industry survey of commercial PES types in the U.S. and Canada was conducted to identify and address critical differences in commercial structures as compared to the military structures in SAFER. The paper concludes with discussion of the potential uses for quantitative risk analysis (QRA) and a description of other explosion effects software

Jan 1, 2007

By James Ludwiczak

This paper consists of the conduct of a forensic criminal investigation of the components, construction, use, and functioning of two suicide bombs. As the title states, the task was to form professional opinions as to whether the bombs would work, would cause property damage, and would injure or kill. The bombs were created and installed by a defendant in a Federal death penalty case where the defendant’s daughter was killed in a shootout with the West Virginia State Police. The two black powder bombs were placed under the front seats of the defendant’s automobile and were designed to function by the use of a toggle switch connected to the automobile’s cigarette lighter. The forensic work first consisted of an inspection of the remains of the wiring system and bombs at the Bureau of Alcohol, Tobacco, and Firearms Laboratory, in Ammendale, MD. This was necessary to determine and detail the wire diameter and lengths, the lengths and size of the wire used, the type of toggle switch used, the type of containers, the type of rocket motors used to initiate the black powder, the manufacturer and amount of black powder used in each bomb, and the type, wraps, and amount of duct tape used for the construction of each bomb. Using this data, tests were conducted by duplicating the wiring system and the two bombs to insure that the system functioned properly. Each bomb was duplicated and initiated to observe the violence produced when initiated in the open air. Duplicate bombs were placed under the seats of a similar type of automobile and initiated. The purposes of the tests were to duplicate the bombs, to observe the violence of the initiation, and to observe the damages to the automobile produced by the initiation.

Jan 1, 2007

The VoD of non-ideal explosives depends on the charge diameter and the thickness, strength and sound velocity of the confiner. VoD measurements are made to evaluate explosives for development, quality control and prediction of field performance. In testing, the container is part of the explosive system and affects the measured VoD. Pipe testing in cardboard tubes delivers the best guide to unconfined critical diameter and minimum VoD range, but the thickness of the pipes affects the result close to critical diameter, even in emulsions. PVC pipes are not good for unconfined test work because they provide relatively strong confinement. Care must be taken to select pipes with constant relative pipe area across the range of diameters. Where pipes are used to evaluate the effect of confinement, the ratio of the wall thickness relative to the thickness of the detonation driving zone in the explosive needs to exceed 0.5 to create full confinement and the ratio of the detonation velocity to the confiner wave speed must be considered. Estimates for critical thicknesses are provided from Non-Ideal detonation models. The relationship between confinement modulus and VoD is discussed and indexes are suggested for quantifying the explosive performance.

Jan 1, 2007

In the March/April 2006 issue of the Journal, we published an ethical dilemma called “Blowing the Whistle.” We received many interesting responses to the article as requested. Some of the responses are printed here. We’ve also included “Blowing the Whistle” again in this issue as a refresher on page 37. Dear Editor, It is in my own personal belief that it would be extremely important if I were the blaster to take the following steps. 1. Hold an immediate emergency meeting with the contractor to convince them to stop work at this point.2. This meeting would need to be held with all powers that be in this construction company. This helps eliminate the hearsay (excluding the farmer). 3. Explain the entire situation to the contractors as it has been presented to the blaster by the farmer. 4. Recommend calling in an engineering or geological firm with the expertise to investigate this matter immediately, and take all immediate action based on findings. 5. Follow up with farmer allow him to speak, (a.k.a. vent) and assure him proper steps are being taken to come to resolve this matter. 6. Be a good listener, and communicator with the farmer while investigation is being conducted. 7. Should the contractor not want, or take any of these recommendations, the blaster himself and his company should question even working for this company ever again. This in itself would not be the class of people we would want to be associated with EVER.

Jan 1, 2007

By Dale Preece

In the late 1970’s and early 1980’s substantial resources were devoted to research focused on producing oil from the vast oil shale reserves in the western United States. Since the oil is solidified in the pore space of the shale, extracting it in production level quantities presented monumental technical challenges. Major advances were made in the methods used to extract oil from the shale in large quantities. Extraction methods evolved to culminate in the underground in-situ retorting process. In-situ retorting relied on explosive blasting of the shale to fragment the rock and induce sufficient porosity and permeability for a burn front to propagate through the oil shale. That burn front consumes some of the oil and liberates a substantial portion of it (~30%) for collection and further processing. Oil shale retorting is a blasting intensive process where the entire retort is rubblized in one very large, delay timed blast. Retort 7 in Western Colorado consumed 540,857 lb of slurry explosive to rubblized 348,940 tons of oil shale. Current rock blasting fragmentation predictive capabilities have evolved substantially since these retorts were designed and tested. It is the purpose of this study to simulate the explosively induced fragmentation of oil shale using state-of-the-art computer codes and material models and to infer retort design implications for future development.

Jan 1, 2007

By W G. Szymczak, Leslie C. Taylor

The University of Maryland (UMD) has conducted a series of small-scale tests using explosive charges buried in saturated sand. Twelve different combinations of depth of burial of the charge and height of the target plate above the soil were tested. The target plates did not deform plastically. High-speed video was used to track the motion of the plate. The video data are analyzed to determine the position and velocity of the plate as a function of time. The results of this analysis are compared with computations performed at NRL using the BUB2D computer code. This code treats the saturated sand as an incompressible visco-plastic fluid which yields according to a Drucker-Prager (frictional-cohesive) yield surface. Comparisons of simulations with experiments are presented. In the cases examined so far, the velocity grows very quickly to a peak and then slows, first with a deceleration greater than one “g,” which then transitions to an approximately one “g” deceleration. An analysis of air drag on the plates has shown that its effect is negligible in the time span of interest. In all cases in which the BUB2D code can be applied, the computations compare favorably with the results of the data analysis. This suggests that the code and model used in the computation are properly capturing the physics of the interaction between the soil and a non-deforming plate.

Jan 1, 2007

By William Yutmeyer, Meredith Hardwick

Since 1996 there have been at least two teams formed within the U.S. Government to develop a consistent set of risk-based standards to be used to govern safety. The first of these was the Risk and Lethality Commonality Team which developed risk criteria associated with protecting personnel during launches at the national test ranges. The second team titled the Risk-Based Explosives Safety Criteria Team (RBESCT) is the subject of this paper.

Jan 1, 2007

By Jim Daly

The word “Enron” has taken on a totally different meaning since its leaders were caught juggling the books, President Clinton’s reputation was destroyed not by what he did but by how he tried to cover it up, Martha Stewart spent time in prison for not being honest. Our society is tolerant of mistakes we humans make but has become very critical about what we do following those mistakes. The blasting industry is in a similar position. We have all heard the stories of the tree stump that came down through someone’s roof, of the windows that were broken, of the casualties that occurred when a blast was not properly guarded. What was done following these incidents? In the mind of the public, not enough.

Jan 1, 2007

By Alton Dunaway, Kevin Sullivan, Charles Gray, Doug Hall, Kevin Grant, Kelly Thiel, John Paulson, Bruce Leland, Cole Boyd

Beaver (Castor canadensis) are responsible for economic losses exceeding $4 billion over the last 4 decades in the southeastern United States alone. A large portion of these damages occurs to public roads and highways, forests, agricultural resources, and other property from flooding caused by beaver dams. The United States Department of agriculture, Animal Plant Health Inspection Service, Wildlife Services (WS) program is a non-regulatory Federal program directed by Congress to assist resource owners with managing damage caused by wildlife.

Jan 1, 2007