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By Philip M. E Thomas

For over sixty years man has struggled to defeat the natural swamp lands known as the Florida Everglades as demand for land to support the burgeoning population growth in the state continued almost unchecked. Over the past ten years there has been a growing awareness that this land development could wipe out a whole ecosystem in a very short time unless steps were taken to reverse the trends. In 1991, a state law called the Marjory Stoneman Douglas Everglades Protection Act was enacted giving power to the South Florida Water Management Board to condemn certain lands for conversion to manmade swamp lands, designed to filter polluting run-off water from the agricultural lands around Lake Ockeechobee.

Jan 1, 1994

By Kenneth Medearis

The accurate prediction of possible damage to historic structures subjected to blasting-related ground motions is not infrequently the dominant factor in whether or not a mining or quarrying operation is allowed to proceed. A recent scenario involving an 1802 Pennsylvania Historic House was resolved satisfactorily, primarily because of the use of modern structural dynamics analysis techniques rather than simplistic peak particle velocity guidelines. One of the associated dominating factors was the truly significant agreement of the analysis results and the values obtained from actual on-site test shot blast motion recordings.

Jan 1, 1993

By Douglas Rudenko

When blasting complaints come, as an industry we often immediately look to the ground vibration as the source of the trouble. Often times we overlook or place less emphasis on the collected air overpressure data. Air blast like ground vibration is an undesirable side effect of blasting and can produce considerable structural response.

Jan 1, 2002

By John C. Didlinger, John L. Didlinger

As we begin the pre-blast survey we need to decide on the number of holes needed for production and a detailed highwall inspection. The survey consists of checking the highwall and placement of barrier cones. At the Elmhurst Chicago Stone Company, Barbers Corner Plant, we use 18-24" orange highway type safety cones. These cones are easily noticed because of their high visibility color in all weather conditions and are placed approximately 20-25 feet from the face and approximately 50 feet apart along the highwall, then the area is checked for back break, under cut, over hang, surface filled area and clay area. This deposit is unique because of the number of clay filled areas and slip seams that meanders through the deposit plus a fault that runs North-Northwest and South-Southeast. This particular limestone deposit is overlaid with glacial sand and gravel and the top weathered stone wanders plus or minus 10 feet in 1400 feet.

Jan 1, 1996

By Matthew Baumann, Bahram Sameti, Tafazoli Zeng Hairong, Edmond Chow

An automated, centralized, image-based rock fragmentation analysis system provides blast engineers with the benefit of minimizing tedious and mundane work, and allows them to focus on their expertise of blast optimization. In typical manually-operated image-based rock fragmentation analysis, much time is spent on collecting proper images, handling and transferring data, and processing for fragmentation.

Jan 1, 2013

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 John P. Ashby

Production blasting is a process of destruction of rock masses in order that ore may be extracted. Many open pit operations are faced with the apparently conflicting requirements of providing large quantities of fragmented rock for the processing plant and of minimizing the amount of damage inflicted upon the surrounding pit slopes. A reasonable compromise between these two conflicting demands may often be found by means of simple engineering of production blasts.

Jan 1, 1980

By Greg Mclellan, Mark Johnson, John Pepper

In this paper, the measured vibrations are plotted in terms of the individual PPV components versus Scaled Distance (SD) on logarithmic scales. The maximum PPV is pIotted on a separate graph and equations are presented to predict the maximum PPV based on sealed distance and prediction level usmg power fits. The prediction levels include a 99.9% curve, which encompasses the data points and provides an envelope formula for determining the maximum PPV at South Florida sites. The dominant frequency distribution is established for the PPV components.

Jan 1, 2001

By William H. Snyer, Hank Cox

A high explosive device using Linear Shaped Charge (LSC) (to rapidly cut vent and drain openings in a rail tank car) is described. In the event of damage to a tank car loaded with a pressurized flammable fluid, it may sometimes be necessary to perform controlled on-site vent, drain and burn operations. Existing techniques required refinement to achieve the desired safety and procedural reliability for use in emergency situations.

Jan 1, 1994

By Dennis Alan Clark

An increase in construction and quarry operations has necessitated blasting activities in areas once considered rural and in the close proximity of transmission pipelines. A method to determine the maximum allowable bending stress by the formulas outlined by the Battelle Memorial Institute report of October, 1962, and the assumed stress comparison with actual measured data is presented. A direct relationship between pipe stress and ground particle velocity is shown, and a method to predict stress by relating stress to charge weight and distance from the shot point is discussed.

Jan 1, 1976

By Alan Minchinton, Ian Kirby, Jim Chan

It has long been known that successful blasting in soft and hard rock can require the use of different explosives. While choosing an explosive of the right energy density is important, the dynamics associated with non-ideal detonation behaviour play an equally major role. Tuning the energy release rate of an explosive to optimise its blast efficiency can be likened to tuning an internal combustion engine to improve its performance.

Jan 1, 2014

By Dieter Froelich, Giles Turcotte

In the near future, Bong Mining Company (BMC) will start mining a new deposit known as Zaweah II which is a narrow iron orebody requiring multiple row blasts with the bench floor as a free face. This called for the development of a new blasting technique. The article delineates the problem and its restrictions related to blasting. It also describes the approach which was taken for developing this new blasting technique which is essentially an application of the cratering theory with near spherical charges. Basic crater tests were conducted using various combinations of hole sizes, explosive strengths and delay patterns. From the results obtained, several alternatives were considered for production blasts and the most promising ones were evaluated.

Jan 1, 1980

By Lawrence W. Hallanger

Anaheim Bay, located at Seal Beach, California, is the site of the Huntington Harbor development of waterfront homes and marine facilities. The main entrance to Anaheim Bay is a relatively narrow channel connecting the bay with the Pacific Ocean which runs under California State Highway One. During the development of Huntington Harbor the old highway bridge was replaced with a new, higher bridge to allow for boat passage through the channel. At that time only the main span decking of the old bridge was removed, leaving the support pillars and the approach ramps in place (see Figure 1). The narrowness of this channel, plus the increasing boat traffic created a situation in which public demand for the removal of the old bridge became significant. Because the bridge was located within the boundaries of the Seal Beach Naval Weapons Station (see Figure 2) the Navy became involved in the bridge removal. Eventually the task was assigned to the Naval Amphibious Construction Battalion One and work began in early 1974.

Jan 1, 1975

By Hu Wenjun

This paper changes the section of copper of copper to aluminum adapter bar into aluminum plate covered one face or double face with copper coat, and changes the conductor material of knife switch, fuse box, plug and socket into steel plate covered one face or double face with copper plate, and manufactures the composite (two layers or three layers) metal plates by means of explosion welding with the plates installed horizontally. Introduced in this paper are the blasting designing technique, manufacturing process and the electrical performances of the explosion bonded products. Besides, this paper presents the designing and manufacturing technique of cumulative charges and their time detonating units for cutting off the retired nuclear submarine pipes. Experiments on cutting off the stainless steel pipes by cumulative flow and on the time detonation are made. Keywords: explosive welding, electric, explosion bonded products, retired nuclear installation; pipe; blasting cutting; cumulative charge; time detonation

Jan 1, 2000

When CIL presented their new theory of the Breakage Process and Delay Blasting at the 74th Annual Meeting of the CIM in 1972(1), there was hardly any open pit operation in Canada that was using longer than 25 msec. delays. To the contrary, 10 and 15 msec. surface relays were common, which in our opinion were no delays at all for open pit blasting.

Jan 1, 1979

By Paul E. Thompson

Current magazine regulations are designed to avoid injury or property damage caused by accidental detonation as well as to store explosives securely. The primary emphasis appears to be the avoidance of unintended detonation or in the event such detonation occurs, the avoidance of damage to surrounding property. Adherence to these regulations largely serves the purpose intended but has caused difficulty in magazine sitting in built up areas. To the extent that magazine siting is too heavily restricted, other more significant dangers such as storage of explosives in more dangerous and less secure places may be encouraged. In summary, the regulations have served rural magazine locations well but may need further study for urban settings.

Jan 1, 1990

By Ken Tunnel

In the spring of 2005, the Lake Superior Chapter of the ISEE invited me to speak about raw materials used for blasting, anhydrous ammonia and the effect of this important feedstock on the cost of ammonium nitrate.The invitation was extended because our company is involved in trading ammonia and the production of ammonium nitrate. In a response to a request to update that presentation, it struck me how events such as hurricanes Katrina and Rita can change the landscape of our businesses.

Jan 1, 2007

By Ruilin Yan, Kameron Ray

This paper reports a simple approach to model the waveform change due to travel distances based on the field measurement. A linear interpolation is used to estimate the waveform at a distance from two vibration waveforms recorded at two different distances. The resulted waveforms are compared with actual recorded waveforms at the point in both time and frequency domains. It shows that the proposed method to estimate the waveform change yield reliable results. The advantages of the proposed method are that it does not require assumptions that a transfer function does and that it is based on purely the measured waveforms that are encoded with in-situ rock properties. The method could be more reliable for far field seismic waveforms and could be an approximation for near field waveform estimation.

Jan 1, 2014

By Shawn Kirkpatrick, Yang Ruilin, Tamara Whitaker

In order to manage blast vibration in soft ground containing large diameter holes and large charge weights, a number of issues must be considered. This paper describes techniques to control and reduce near-field blast vibrations absorbed by highwalls in soft ground. Sympathetic detonations need to be controlled. Sympathetic detonations can cause excessive vibration due to an unknown number of charge weights firing out of sequence. The excessive vibration can cause damage to the ground. Sympathetic detonations can be controlled through proper design of blast patterns and, in some cases, through the use of specialized electronic detonators.

Jan 1, 2009

By J R. "Dick" Daniel

Over the past several years, the Hercules Technical Service Group for the Explosives Department has produced a series of programs for the TI59 programmable calculator dealing with explosive application problems. These programs have been made available to both our internal staff and to the Hercules explosives distributor organization. Several of these programs have found good acceptance and wide usage.

Jan 1, 1984