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By Thomas J. Snyder

Modern quarry management should be alert to every opportunity to improve productivity and reduce operating costs. In this paper, the author outlines areas in which explosives suppliers should be encouraged to propose changes. He also supplies guidelines for evaluating these proposals, suggests yardsticks for measurement, and stresses the need to be open-minded when dealing with imaginative, innovative concepts.

Jan 1, 1988

By Dale Preece, Stephen Chung

Mining and quarrying industries recognize blasting as the most effective method for breaking and removing large volumes of rock. However, the economics of blasting are often offset by the costly trial-and-error approach. Researchers in the field of blasting therefore design models to help eliminate the number of trials before finding the best feasible solution. Because of the complexity of blasting, a capable model would allow the designer to look at more than one variable at a time so that the most critical factor can be tackled.

Jan 1, 2002

By D E. Siskind

The Bureau of Mines performed a comparative study of nine sites at eight surface coal mines to determine if the presence of near-surfaced underground abandoned workings resulted in the generation of adverse long-duration, low-frequency blast vibrations. Six of the nine sites had underlying workings, and two had thick layers of low-velocity unconsolidated surface material.

Jan 1, 1990

By Shad M. Sargand, Manseok Chang, Glenn A. Hazen

Customarily, peak particle velocity of surface wave vibrations has been the recommended criterion for the prediction of blast damage to structures. Currently blast spectrum and natural frequencies of a structure have been also recognized as important for predicting damage potential. While others have considered the importance of structural frequencies, they have not analyzed the structural response spectrum when establishing damage criteria.

Jan 1, 1992

By H. Frank Murati, D. S. "Sax" Saxena

The presence of a mobile home park with drinking water wells created a unique geoenvironmental deterrent to the developer’s plans for effective rock blasting, excavation, and development of water management areas (lakes) in connection with the construction of Crown Colony Resort, a residential cum golf course community in southwest Fort Myers, Lee County, Florida, USA.

Jan 1, 2002

By Phil N. Bradbury

"During a routine belt tightening of all cost centers, the management at the Martin County Coal Surface Mines, located in Martin County Kentucky felt that a thorough investigation of the drilling and blasting program could possibly pinpoint areas where the cost could be cut without sacrificing production. Upon close inspection of the drill benches it was noted that the actual layout of burden,spacing and stemming varied a bit from the actual blast design that the management had outlined for the blasters. This paper will outline the method of reducing the drilling and blasting cost at the Martin County Coal Operation."

Jan 1, 1986

By Krishna Nand

For assessing the safety of structures during underground explosions, ground particle velocity gives the best damage criteria, and 100 mm/see of ground particle velocity has been internationally accepted as the threshold value of safety (no damage). Results of extensive controlled underground explosion experiments conducted by the author to study the effects of ground vibrations on specially prepared concrete blocks, and also on low rise buildings and dams showed that no damage normally occurred when ground particle velocities were less than 100 mm/sec. Analysis of a large number of accelerograms from a dam site in India also indicated that no damage occurred to normal structures when integrated ground particle velocities were less than 100 mm/sec. Major damage in well built structures like a dam was noticed for ground particle velocity as high as about 350 mm/sec. These results are also generally substantiated from damage data obtained for various structures during other earthquakes, including Elcentro (1940), Taft (1952), Parkfield (1965), and San Fernando (1971). These studies, therefore, suggest that the damage criteria during underground explosions and earthquakes are similar; and 100 mm/see of ground particle velocity seems to be the general threshold value of safety (no damage) against ground vibrations.

Jan 1, 1988

By Dean E. Albon

The author gives a brief resume of his observations of drilling and blasting supervision in surface coal mines during the past thirty years and recommendations for upgrading this supervision to the category of a professional.

Jan 1, 1979

By Douglas Anderson

In the early 1980s, a method for controlling blast vibrations other than by modifying the Scaled Distance came into use. Research studies had indicated that blast vibration could be simulated by detonating a signature hole with the vibration monitored at critical locations, and then using a computer to superpose the waveforms with varying delays. By choosing delay times that create destructive interference at frequencies that are favored by the local geology, the “ringing” vibration that excites structural elements in houses and annoys neighbors could be reduced.

Jan 1, 2008

By David Harrison, Edward J. Walter, Meitra Ferek

A pre-blast survey can be a great tool in the prevention of blasting complaints and subsequent damage claims. In today's highly competitive industry, we are always looking for ways to become more cost effective. This paper investigates the importance of pre-blast surveys not just for regulatory compliance, but as an overall long term cost cutting and public relations tool.

Jan 1, 1995

By Rolf Koenig

A fire aboard a vessel transporting explosives and detonators manufactured by Dynamit Nobel endangered the cargo. Due to the special safety properties of the detonators, no mass detonation occurred.

Jan 1, 1989

By Ettore Contestabile, Cameron Thomas

Implosive-type electrical/mechanical connectors such as XECONEX have been used extensively for joining electrical transmission lines. This implosive action of explosives has also been applied to other forms of high energy metal working with excellent results. However, as with many other products, the inherent blast energy of these units has caused some environmental concerns especially when used in proximity to inhabited areas.

Jan 1, 1995

By Donald Little, Larry Unger

This paper will give a detailed insight into hard rock, large diameter surface blasting including some practical tips to improve blasting practices. These tips will be non-technical, of the nuts and bolts type, intended to help the man in the boots. The paper will begin with the importance of communication between the engineering department and the blasters. What looks good on the mine development map might not blast very well. Tight inside corners, 90 degree outside corners, too few rows; are a few of these problems.

Jan 1, 2006

By Rob Farnfield

The control of vibration from surface mine blasting by the application of detonator (cap) delay techniques has been universally accepted for many years. For almost as long it has been known that, for delay techniques to be effective, a minimum of 8 milliseconds delay must exist between blast holes.

Jan 1, 1999

By Julio Cesar Barbosa de Freitas, Rafael Gonçalves Araujo, Túlio Soares, Jair Koppe, Augusto Ferraz Ribeiro, Pedro Barreto Garcia

This study thesis was motivated by the fact that it is of fundamental importance for open pit mining that the slopes initially have a geometry in accordance with what is proposed in the mining planning. This occurs because an inconsistency in this design can impact the operational safety and economic solutions of the mining project. These consequences can be explained by the fact that rock blasting close to mining limits requires specific study due to the attention required. Because, when this operation is not carried out properly, the mining plan in the mine may not be respected and may create risks to the operation due to the presence of unstable blocks on the slopes (Mackenzie). In this sense, Mackenzie (2004) cites pre-split, trim blasting and buffer as commonly used explosive blasting techniques that aim to limit damage beyond the projected wall. Therefore, Enaex Brazil realized the need to better understand the pre-split method. To do this, it is necessary to understand how the energy released during detonation is perpetuated in the rock mass when this technique is used and when it is absent. Thus, this analysis is based on a seismic study that allows the creation of vibration attenuation laws and an elementary wave damage model, which allows the local characterization of the rock. With this model it is possible to relate the peak levels of vibration during blasting and the extent of damage, but a critical level of vibration (PPVc) and its relationship with the Uniaxial Comprehension Resistance (UCS) are also defined for the start of fracturing and its level (McKenzie et al, 1995). And, mainly, this work aims to address a way to measure the pre-split filter potential by comparing the attenuation law with and without pre-split, ultimately knowing whether this finishing blasting is being effective, to understand the pre-split filter capacity.

Jan 21, 2025

By Larry Schneider

In the construction field and to a lesser degree in mining, flagman are often necessary to move traffic and or pedestrians through work zones. Everyone readily recognizes that they are essential for the safety of the general public and the employees on the job. What is not often considered is the safety of the flagmen themselves. Actually, let’s call these employees “flaggers” recognizing the fact that there are as many women as men doing this job. The first problem we need to overcome is the misperception that flagging is a low skill function that can be done by any untrained employee. The reality is that the flagger works in a very hazardous position with serious responsibility for the safety of his fellow employees and the public at large. And to do this job properly re q u i re s that the flagger receive sufficient training before being sent out to the highway. It is also necessary to convince the flagger of the value and importance of their job in order to motivate them to do a professional job.testing, documentation of both, and accurate re c o rdkeeping are key aspects of HM126F. Of course, training and documentation requirements will vary depending on the type of operation involved, and there may be some differences in the application of requirements depending on your jursdiction. Nonetheless, failure to train and properly document such training can result in heavy fines and/or penalties.

Jan 1, 2004

By Lina Lopez, Jose Sanchidrian, Manuel Lopez, Pablo Segarra

Previous work in which rock properties and blasting parameters (geometry, charging and timing) were reported together with truck filling times, is taken as a starting point for a thorough analysis of the influence of the former on the mucking velocity. The experimental set was composed by 11 blasts made in an open pit mine. Non-parametric, distribution-free statistics is applied. The mucking rates (in bank cubic meters per unit of bucket volume and per hour) appear to be clearly dependent on the explosive energy and powder factor, both magnitudes combined as energetic powder factor (energy per unit of rock volume). The mucking rate is a non-monotonic function of such factor in the range of the blasts analyzed. The determination of the function is optimum when the fraction of the explosive below grade is not considered and when the explosive energy is qualified as that delivered at a partial detonation regime. Different types of loaders seem appropriate for different energy levels. At low levels both front loaders and rope shovels obtain small productivities without a statistically significant difference in their performance. At high energy levels, front loaders qualify higher than rope shovels. Mucking velocities can be equally small at low energy powder factors and at high ones if rope shovels are involved.

Jan 1, 2008

Blastserve, ISEE’s Listserve is being replaced by our new Blasters Forum-online, an exclusive member benefit. Our goal is to provide an ISEE forum for you to network with your peers and exchange technical information and get answers to your technical questions. This forum is unique in the fact that only ISEE members are permitted to review or post on the site. Over time you will be able review the discussion history and use the archived discussion as a valuable resource for trends in the industry. The following are a sample of the discussions that too place recently on Blastserve

Jan 1, 2013

By Lyall Workman, Jack Eloranta

In this paper results of drill to mill research are examined. It is found that several descriptors of blasting results change when the powder factor is increased. Fragmentation shifts toward a finer distribution. The Bond work index decreases and the product of the t10 model breakage parameters increases. Both of these indicate more softening of fragments. There is research that found large differences in bond work index and other studies that find a much smaller decrease. Even at the lower decrease, however, some savings in energy cost can accrue in hard ores ground to small size.

Jan 1, 2009

By George E. Jackson

ANFO, as a blasting agent, is used in large quantities in coal surface mines. It can be purchased on the open market or through reliable suppliers. The blaster in the field must assume that his ANFO is homogeneous, consistent, and nearly identical on a daily basis. A quality control program will enable him to be assured of the correct product. Therefore, the material cost and operational efficiency can be better controlled.

Jan 1, 1978