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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 Corry Goumans, Dan Agostino

Photo 1. Demolition work on the Pitt River Bridge. The drill crew is using the 3800 Gardner Denver Air Track to drill the holes on the Bridge turning dolphin. The barge in the background is used for support.

Jan 1, 2013

By Thierry Bernard

Today, experimental measurement of the shock energy/gas energy pair, or pool test, has now become virtually standard. But pool" energy per m(exp 3) of bedrock has no significance for explosives used in any medium other than water.

Jan 1, 1994

By R Mancini

Explosive charge action on the medium is intrinsically dynamic (fast rising and fast vanishing). On the contrary, information available on rock strength is drawn from static behaviour, and it's commonly used to characterise the rock, even in blasting problems.

Jan 1, 1995

By Bonifacio Digay

Stawell Gold Mines (SGM) is an underground mining operation located in Victoria, Australia.The mining method employed is long hole retreat stoping, utilising up and downholes and artificial concrete pillars. Stawell is currently mining the Golden Gift and Magdala orebodies.

Jan 1, 2012

By Stephen A. Rholl

Computer software has been developed which uses fast Fourier Transform (FFT) techniques to analyze the frequency spectrum associated with peaks in ground vibration time histories. The procedure consists of filtering the FFT of a time history into individual frequency components.

Jan 1, 1996

By Jay P. Tobin

This paper will address the legal standards applicable to construction blasting lawsuits and offer best practices suggestions for pre-blast inspections, documenting the construction blasting work, recordkeeping, and effectively participating and partnering in the defense of a construction blasting lawsuit.

Jan 1, 2015

By Kfw Eick

The paper describes the use of the Nonel millisecond delay blasting system in narrow, deep, tabular ore bodies and briefly describes the standard stoping method as used on Harmony Gold Mine and compares this with the new Nonel short panel system.

Jan 1, 1990

By Edward Fitch

The DOE is evaluating Yucca Mountain, Nevada as a potential site for disposal of high level nuclear waste. Yucca Mountain is located approximately 160 km northwest of Las Vegas on the western edge of the Nevada Test Site and the Nellis Air Force Range. An exploratory tunnel has been constructed through Yucca Mountain for site characterization. A controlled drilling and blasting technique, smooth wall blasting, was used to excavate the TBM starter tunnel and alcoves off the main tunnel to provide areas for scientific investigation. Fundamental to the blasting program has been the use of two blast design equations used in concert to minimize blast damage to the surrounding rock mass. The first of these equations was developed by Roger Holmberg and estimates near-field peak particle velocity that is the basis for minimizing blast damage to the host rock. The second of these equations was developed by B. H. Sanden and provides bore hole pressure estimation which allows controls to minimize crushing of the rock mass along the perimeter yet allowing enough force to create tensile failure between perimeter bore holes. This is key to the smooth wall blasting technique. To date, essentially the same controlled drilling and blasting program has been in place for all excavation requiring controlled drilling and blasting at the ESF. The controlled drilling and blasting program uses an iterative process to achieve continuous improvement in the blast rounds. This involves interaction between Architect and Engineer (A/E), Constructor, and Testing Coordination O&e (TCO) to ensure each blast round successfully meets the expectations of affected participants. The A/E requested that the TCO provide validation of the near-field peak particle velocity estimation under the Construction Monitoring Program. Data gathered under this program were reduced by statistical analysis and used to verify blast design parameters and provide a site specific blast damage relationship.

Jan 1, 2000

By Thomas L. Barkley, Steve Salli

In the past, blasters have attempted to evaluate the results of their blast designs and make corrective adjustments to improve the blasts' productivity and value to the mining operation. The methods employed have nearly always been "eyeball" evaluations and "trial and error" corrections.

Jan 1, 1997

By R. Wharton, M. Bagley

Following a series of papers relating to the certification of explosives for sale in member states of the European Union presented at previous ISEE conferences, this poster paper has been prepared to stimulate discussion and debate on the recently published European Directive on Pyrotechnic Articles.

Jan 1, 2008

By Katherine L. Heineken, Timothy J. Tope, Kim David Murphy

One method for small arms disposal is the use of a deactivation furnace or explosive waste incinerator. There are numerous hurdles a facility typically encounters to get the furnace or incinerator fully operational and permitted. For example, one Department of Defense installation was in the permitting process 7 years, which included numerous facility upgrades and modifications. This paper will discuss the technical approach for proactively addressing permitting issues and requirements and will identify potential pitfalls to avoid as well as ways to reduce costs. For example, when determining the waste profile, the facility should forecast its treatment needs (taking into account the net explosive weight limits of the furnace/incinerator) and then classify the wastes into "chemical families" based on the type and composition of the wastes. One waste from each family should then be selected for potential inclusion in the trial burn. Modeling the waste disposal can help to narrow down the number of wastes requiring characterization during a trial burn, as well as the number of analyses.

Jan 1, 1997

By U. Prasad

This paper summarizes the investigation carried out on a wide range of rock types, subjected to high velocity impact to simulate explosive action. A Split- Hopkinson Bar apparatus was used to generate the high velocity impact. The rock samples included both homogeneous and isotropic, and anisotropic types. The strain rate achieved was between 600 and 12OO/sec, The respective measured dynamic compressive strengths were compared with their low strain-rate or static values. It was found that the ratio of the dynamic to static values ranged between 2.5 and 4.6. It was also determined that the high strain-rate loading produced finer fragment size distribution than the static loading. The fragment size distribution from the two strain-rate regimes has been further analyzed to establish correlation with rock types and the strength characteristics. The results also confirm that high strain-rate loading (i.e. high detonation pressure and high velocity of detonation in an explosive column) would significantly affect the degree of fineness in a blast.

Jan 1, 2001

By Michael S. Wieland

Delay detonators that are damaged by cross-hole wave interactions degrade blasting work and raise the risk of incidents. Damaged detonators impose risk, because they can retain sensitive explosives that respond to stray energy during recovery, inspection or disposal. Laboratory techniques were developed to rank the ruggedness of delay detonators under replicated field-shooting conditions. The hazards are tremendously magnified if trial detonators are installed directly in secondary explosives to rank initiation strength. Therefore indirect ranking techniques were sought that mitigate the risks without compromising the worthiness of the method. Four types of hardware fixtures, referred to as simulators, were developed to yield distinct forms of transient compression. The shock and rift versions generate compression pulses representative of in situ waveform components. The waiting time, until the trial detonator functions, duplicates typical delay periods. The trial detonator is mounted within water, which has a density and inertial resistance comparable to most blasting explosives. The work output from the trial detonator explosion is registered as fixture wall-expansion. This work output determines malfunction results, regardless of which type of simulator is used.

Jan 1, 1997

By Michael S. Wieland

Underground coal-mine explosives (permissibles) can be substantially degraded by the underground stress waves from the explosion of neighboring borehole charges. This cross-borehole interaction generally yields the worst receptor (impacted) charge performance when the borehole separations are too close. For explosives which recover, the receptor degradation is worst when the delay until firing is small. Except for a poor quality muck pile or unreacted cartridge fragments, degraded charge malfunctions of this type are difficult to detect in coal-mine delay blasting. A simulator which reproduces the underground wave/receptor charge interaction and special underwater donor/receptor tests were utilized to study this transient desensitization problem. Test results revealed reductions in receptor energy output, delayed transitions into detonation, inferior reaction rates, or sympathetic reaction responses from the impaction. Tests on detonators showed reduced tip-strength, abnormal functioning times, or sympathetic firing as a result of transient impaction. The cross-borehole desensitization and sympathetic reaction response problems warrant concern because they are logical mechanisms for raising the risk of hazardous mining conditions, including blown-out shots, flyrock, charge deflagration, and methane/coal dust ignitions.

Jan 1, 1987

By Salah A. Taqieddin

In an open pit, or a quarry blasting operation, a muck pile of broken material of given size and quantities suitable to a load/hauling system is normally created at the foot of a bench. Fragmentation can be used to evaluate the efficiency of that blast configuration.

Jan 1, 1987

By A N: Zditovetsky Shishov, M G. Menzhulin

At present in a building industry demand for products from granite, gabbro and other rocks, steady to erosion, natural and chemical weathering, was essentially increased. It has caused the enlargement of exploitation of stone block deposits and necessity of creation of new technologies of hard stone cut.

Jan 1, 1996

By Judy Konya Bowles, Calvin J. Konya

Blast vibration and air blast are commonly blamed for damages to residential as well as commercial structures. Mining and construction companies are often required to spend monies in court defending themselves even when vibration and air blast levels have been monitored by seismographs and are extremely low.

Jan 1, 1992

By Tom Donnelly, Roger C. Ilsley

Remote telecommunications seismographs were used to monitor blast vibrations at two historic structures in Cedarburg, Wisconsin during adjacent sewer line construction. The purpose of the vibration monitoring program at the historic structures was to maintain blast vibrations below limiting tolerances established by the Wisconsin State Historic Society.

Jan 1, 1991

By Yu Yalun, He Jun

Wavelet Analysis is very effective for processing the high-varying signals by its good localization properties. We studied its feasibility of application in the field of blasting seismic signals processing, found the basic representation wavelet for blasting seismic signals analysis, and analyzed a concrete engineering example with analyzing wavelet.

Jan 1, 1997