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By Ann Barron

Commercial drivers have new guidelines regarding how long they can stay on the road without taking a break. Transportation officials say the new Hours of Service rule that took effect January 4th will reduce driver fatigue and prevent hundreds of injuroes, thousands of crashes and save the American economy about 628 million dollars a year.

Jan 1, 2004

By Randy Wheeler

The importance of having full wave form information for recorded blast events cannot be overstated. Knowing the peak particle velocity and the frequency at the peak are the tip of the iceberg. This presentation will focus primarily on using the FFT (fast Fourier transform) for detailed frequency analysis. Employing linear superposition to evaluate timing effects on amplitude and frequency will be discussed.

Jan 1, 2005

By R. Reed Skaggs, William Gault, Douglas Kooker

Both armored personnel carriers and light combat vehicles are increasingly vulnerable to a variety of highly lethal antitank land mines. As a result, there is a need for modeling and understanding the interaction of mine blast products with respect to the resulting loading and damage mechanisms inflicted by explosive blast and impact on vehicle structures. However, the mechanics of blast soil interactions are still poorly understood. The objective of this investigation is to computationally simulate a series of experimental buried mine explosions in saturated sand soil -- over a wide range of scale – and compare the predictions of blast loading to data. Small scale tests have recently been conducted at the University of Maryland with a few grams of RDX acting against an aluminum plate, while recent full-scale tests at ARL involve several kilograms of TNT against 12,500 kg of RHA. The ARL measurements reported here are based on the Vertical Impulse Measurement Fixture (VIMF) facility, a structural mechanical device that responds to blast loading by measuring the vertical displacement of a fixed mass vertical guide rail, which is a direct measure of the imparted impulse. CTH predictions for vertical momentum of the target plate are within 60 – 80 % of the reported impulse data for this wide ranging set of tests. One of the comparisons, however, suggests that the TNT charge in a particular VIMF test may not have fully reacted.

Jan 1, 2005

By D S. Preece

The aim of the present work is to investigate the effects of shooting multiple explosive charges, in the same borehole, on the amplitude and frequency content of the generated seismic wave. The work also investigates the effect of the coupling medium used in the borehole on the quality of the generated seismic wave. The delay period between the shots is on the order of months and up to a year. The investigation utilizes a numerical modeling approach which is capable of modeling the detonation of explosives as well as shock and stress wave propagation in solids.

Jan 1, 2012

By Robert Hopler

The use of electrical fuzes is rapidly superseding the old cap and fuse method of firing blasts. It is therefore desirable that the details of this kind of blasting should be more generally understood

Jan 1, 2006

By Taner Sumer, H Altay Guvenir

Fragmentation in rock quarries is tried to be achieved by changing the specific charge, drill pattern and bore hole diameters by different experts. This paper is a brief summary consisting of the utilization of practical experiences of the other group on cost optimization procedure that takes into account blasting, transportation and crushing as a whole process and optimize the cost by defining the optimum gelatin based explosives to be used as a main primer of anfo in three different limestone and granite quarries, with similar rock characteristics.

Jan 1, 1993

By D P. Yang, Yang R. G

The laws of throwing and heaping of engineering blast are important for making use of throwing and heaping of thrown body to form certain shape, such as building dams by directional blast. The article is to apply Ballistic theory of single thrown body to take the throwing course of thrown body as the movement of particle system, and then delimit the total of thrown body into units of thrown bodies, and regard the heaping shape of single thrown body as a perfect triangle, and found a quantitative relation between macro-geometry parameters of perfect triangle and designed parameters of explosives. The theory has been adopted in blast practice and gotten good effects.

Jan 1, 1999

By Jack Elorenta

We often hear that, "Blasting was an art, but now blasting is now a science". 'Scientific' blasting implies that we have quantified and reproducible measurements of the feedstock and product of the blasting process. However, the industry's reluctance to adopt two key technologies, drill monitoring and optical size analyzers, sheds doubt on the claims of scientific blasting.

Jan 1, 2003

By John Vynne

Too often, a mine’s operations, including drilling, blasting, loading, hauling, crushing, processing, etc., are considered independent steps, rather then a continuous process. In fact, these are interdependent operations with each step in the process having an impact on subsequent operations. If the effectiveness of the drilling and blasting operations can be improved, they will impact the entire mining process. Some of the resulting improvements include: level benches on grade; fragmentation and diggability with the result being reduced loading times; haul cycles improvements; and the crushing and milling operations will be more efficient and less energy consumed. Thunderbird refers to this as “Drill to Mill” information cycle or process. This paper focuses on two of the technological enhancements Thunderbird has added to its drill monitors that allow the mines to impact the “Drill to Mill” concept. These enhancements are: incorporating global positioning satellites into drill monitors; and radio off-loading of data.

Jan 1, 2001

By Stanton Johnson

Africa has a long history of mining and has been one’of the world’s greatest sources of gold and other mineral resources since the days of the Egyptian pharaohs. Mining in Africa has been dominated by South Africa since World War II. However, in the past 10 to 15 years, other African countries are beginning to slowly catch up with South Africa. Ghana, formerly called the “Gold Coast” is located on the West Coast of Africa. Ghana has been involved in mining activities for well over 100 years. Most of the mining activities centered on the mining of gold and were to a large extent limited to underground mining methods. With a more liberal economic policy regarding the exploration and exploitation of Ghana’s mineral resources, mining activities are beginning to evolve to a much larger scale. Drilling and blasting which is an important aspect of this evolution is also changing due to the involvement of foreign-based mining and explosives companies.

Jan 1, 1998

By Paul Downing

When was the last time the documents and paperwork were cleaned out of the glove boxes, door pockets, under the seats and above the visors in your company vehicles? Insurance cards that expired three years ago and vehicle registrations from 1999 through 2003, for instance, don’t do any good and just take up space

Jan 1, 2008

By Wes Bender

Considering the current interest in Global Positioning System (GPS) usage, it might be timely to look at a more efficient means of utilizing these instruments. The GPS system currently utilizes 28 satellites (4 are spares) circling the earth in an inclined orbit. Normally at least six satellites are within your area of reception at any given time. The satellites broadcast an extremely accurate time signal and an almanac containing all the satellites’ orbital data. This information is updated regularly as the satellites circle the earth. Your GPS receiver, once it has picked up one satellite’s broadcast, can then determine which other satellites should be available for plotting.

Jan 1, 2002

By Jerry Wallace

This project consisted of blasting for expansion of a major interstate natural gas transmission pipeline pump station. The pump station handled 400-500 million cubic feet (1 l- 14 million cubic meters) of gas per day.

Jan 1, 1996

By D T. Froedge

At the 1990 Symposium of the Society of Explosives Engineering, D.T. Froedge, President of GeoSonics Inc., presented a paper entitled "Differential Topographic Vibration Isomapping", which detailed the capabilities of GeoSonics' new Iso-Seismic Service. In this paper Mr. Froedge described how one hundred or &ore free-standing miniature seismographs called Micro-Seis Units, randomly positioned around a blast, could accurately reveal the effects of sub-strata geology on surface ground vibrations. The paper went on to note the "regression analysis of scaled distance versus recorded particle velocity" as being an inadequate predictor of peak particle velocity. This is due to the fact that the calculated "regression analysis" formula for any site is predicted on the wars; case assumption because of a homogeneous and symmetrical sub-strata geology, a condition that rarely, if ever, exists.

Jan 1, 1992

By T Davids, B J. J Botha

The presence of an extensive soft siltstone layer in the middle of the inter-burden sequence of rocks at Syferfontein Colliery in South Africa prompted tests to determine the effect of different mid-column decks of inert material in the siltstone layer. The objective was to achieve significant cost savings in explosives use whilst not degrading dragline productivity. An important factor that had to be considered was that the initiation systems available in South Africa are not accurate enough to ensure simultaneous initiation of explosives decks in a hole.

Jan 1, 1994

By Ronald L. Cocklin, Vivian Patz

Blasting techniques are becoming increasingly sophisticated as the need for improving mining efficiency grows. One of the areas of blasting that has never been fully exploited, due to a lack of a control and reliability, is the initiation of explosives. Expert Explosives have taken on the challenge to not only provide an initiation system that offers control and reliability, but also provide benefits that are critical to enhanced mining productivity. These benefits can only be delivered through the medium of electronics and computer controlled systems.

Jan 1, 1995

By Steve Dillingham

Whenever misfired holes or portions of misfired holes remain after a blast is fired, a hazardous situation exists until the unfired explosive materials have been disposed of properly. Yet, there are so many factors that can contribute to misfires that it is impossible to give blanket instructions on how to handle them. To complicate matters, misfires today are rare due to reliable blasting products. As such, it isn’t very surprising that many blasters have never had to deal with a misf i re condition. While the likelihood of a misfire occurrence is minimal, you should always be pre p a red to handle a misfire should you be involved in such an event. To begin, every blaster and blasting org a n i z a t i o n should develop a misfire policy which contains the company’s safe operating pro c e d u res, emergency contact list, as well as any regulatory compliance re q u i re m e n t s . Tailgate and/or company-wide safety meetings should communicate the company’s contingent misfire pro c ed u res and any special site-specific precautions BEFORE the start of any project.

Jan 1, 2004

By Shi Hongchao, Zou Zou Xinkuan, Zhang Jichun

As drilling and blasting is carried out in an urban tunnel, which is adjacent to an existing building or structure, the balance between blasting-induced vibration reduction and drivage efficiency is a most important issue that must be resolved properly. Therefore, a new cut blast method named Stepped V-cut millisecond blasting (SV-cut) was developed by optimizing the most common used Vertical V-cut blasting method (V-cut). The most significant features of SV-cut lie in the utilization of sublevel interval charging structure and millisecond delay blasting technology in cut hole and the cut-cavity formed from outside to inside sequentially. SV-cut provides advantages of high borehole using ratio, low vibration level, and satisfied advance per attack. Based on the principal of millisecond blasting, the rock fragmentation process and the vibration reduction mechanism of SV-cut are analyzed. Determining methods of blasting parameters, which do have significant effect on vibration intensity and cut-cavity formed quality, are proposed according to the forming requirement of both outer and inner cut-cavity and vibration reduction. In order to compare the performance between SV-cut and V-cut, field blasting experiments were performed in the blasting engineering of Yamalike twin-arc tunnel, which closely passes over aged parallel tunnels. Blasting results show that SV-cut blasting is proven as an effective tunnel blasting method for both increasing blasting effects and decreasing blasting vibration. Comparing SV-cut with V-cut, the SV-cut can increase blasting drivage about 8.5% and reduce the vibration intensity induced by cut hole blasting 30% at least.

Jan 1, 2015

By Steve Colburn

The new CRITERION Survey Systems utilize both theodolite mounted and hand held reflectorless distance meters. These are eye safe, easy-to-use, and specifically designed to endure the harsh environments characteristic to the mining, quarry and explosives industries. Survey data collected by the systems is digitally stored in a ruggedized data collector and then processed with a specialized, new Windows-based interactive software program, which can be run on any standard PC.

Jan 1, 1995

By Unknown

Threats to Industry Theft Potential

Jan 1, 2006