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By Jason Baird, Seokbin Lim

Run up is a factor in Linear Shaped Charge (LSC) cutting for which an account must be made. It occurs on the initiation segment of the charge, and the cutting performance during this period is significantly lower. Previous investigations by the UMR Explosives Group observed that similar effects occur not only with LSCs but a wide range of other explosives applications, including explosive-driven flux-compression generators. Prior to this investigation, it was believed that the main contributing factors to run up were from the combined effects of explosive run up (detonation pressure), lack of confinement at the free, initiation end of the charge, and penetrator transition from segmented pieces to a long-rod penetrator blade. As an initial step to understanding the mechanics of LSC run up, a series of investigations was performed in which the testing series was divided into several sub-categories (explosive detonation pressure run up, lack of confinement and long-rod penetrator concept) in order to reveal the effect of each on the run up. Predominantly, commercially manufactured LSCs were used for the investigation, and the entire testing was completed by the UMR Explosives Group.

Jan 1, 2006

Jan 1, 2002

By Carlos Agreda

The rock blasting environmental impacts such as: flyrock, groud vibrations,airblast,and/or noise, dust and fumes are identified and mentioned. Some comments on the correction factors that might be taken into consideration to calculate the initial velocity and the maximum projection of the rock fragments are mentioned as well.

Jan 1, 1995

By Beau Bryson, Tony Cooley

The following paper is a technical discussion depicting the type of blasting procedures used to control vibration levels. The blast vibration control criteria that was established and the type of monitoring program that was used. Also, the importance of good communication with the concerned neighbors.

Jan 1, 1985

By Gordon F. Revey

Hanging Lake Joint Venture recently excavated two conventional 42 foot diameter highway tunnels in the difficult ground conditions of Glenwood Canyon, Colorado. This paper outlines the type and success of the various Controlled Blasting Techniques that were used to minimize overbreak in the portal and tunnel excavations. The different Smoothwall and Cushion Charge loads used in the different ground types are described in detail. Delay Timing and Drilling Pattern variations are also discussed.

Jan 1, 1991

By Douglas Lindsey, Glenn Hazen, Shad Sargand

"With the innovation of computational equipment, an exact analysis of structures as dynamic systems is more approachable. Accordingly, the dynamic system can be established, if the natural characteristics such as the natural frequency and the damping fraction of a system are known. Through dynamic analysis, the response of a structure can be predicted from ground vibration, and it becomes possible to forecast the damage potential to the structure with reasonable accuracy. Most vibration will appear as single harmonic or superposition of waves that consists of several harmonics with different frequencies. A vibration signal can be expressed, therefore, as the function of sine waves. If a signal is periodic, the particular harmonic with the smallest frequency will befundamental and frequency of the others will be multiples of the fundamental frequency."

Jan 1, 1993

By Dennis A. Clark, Richard E. Calvin

As the scarcity of mineral resources increase and subsurface mining activities expand along with simultaneous surface mining in coal, industrial minerals and rocks, along with metals, the need to insure safe conditions is paramount.

Jan 1, 1981

By Richard J. Mainiero, James Q. Wheeler, Lewis H. Kopera, Yael Miron, Solin S. W Kwak

The research reported here was part of an effort to evaluate the safety of a process to recover TNT from MK-9 depth bombs by the autoclave meltout process. In this process the depth bombs are heated to 121oC so that the TNT will melt and run into a vat. Unfortunately, asphalt lining the inside surface of the bomb also melts and flows out with the TNT. Prior to this study, it was not known what effect the asphalt contamination and the higher than normal process temperatures (121oC) would have on the sensitivity of the TNT.

Jan 1, 1996

By Robert F. Dexter

This paper discusses the Federal requirements of this regulation for the importation, manufacture, distribution and storage of explosive materials. The interstate or foreign commerce in explosive materials, licensing of manufacturers, importers and dealers, issuance of permits, the conduct of business by licensees and operations of permit tees and the storage of explosive materials.

Jan 1, 1975

By Unknown

ATF has provided a Guide to Recording Suspicious Persons Description in the Safety & Security Brochure. This guide may be useful for recording descriptive information on any suspicious individual. Suspicious activities can be reported to ATF’s 24-hour hotline listed in the front of the Guide or to your local law enforcement authority.

Jan 1, 2009

By G Dean Barrett

Just one year ago at the 1986 Annual Meeting of the Society of Explosives Engineers, Dr. Calvin J. Konya presented a paper entitled "Presplitting Granite Using Pyrodex, A Propellant.'' Since that time more evidence has been developed to support the concept that "...gas energy can be the principal splitting force and that the stress wave or shock wave is not necessary to cause the presplitting action to occur." Work done in Vermont and Georgia is presented, and the ability to split granite without causing radial cracking of the bore holes is demonstrated.

Jan 1, 1987

By E Castelli, M Fomaro, R Mancini, M Cardu

The economic return of rock blasting is not provided by brute volume of broken rock, rather by the amount of marketable product. That is the case of the porphyry quarries of Trento district, whose output is mainly absorbed by road paving and building facing elements production.

Jan 1, 1995

By B. A. Cheeseman, R. Skaggs, C. F. Yen, S. Wolf

Shallow buried explosives pose a significant threat to lightweight vehicles and their onboard personnel. To date, designers of lightweight vehicles are limited in their knowledge of what occurs during the blast. The high intensity, short term loading imparted by the explosion is enormously complex and can be significantly affected by a number of parameters including the size, shape, type, detonation point and depth of burial (DOB) of the explosive and the type, density and water content of the soil. Recent advancements in numerical simulations have enabled the complex blast event to be accurately modeled by coupling Eulerian and Lagrangian analyses: the former is well suited to modeling the blast and while the latter, the structural response. Further validation of the modeling technique is considered in the current paper, which details simulations performed utilizing the coupled Eulerian-Lagrangian analysis to the study the blast output of explosives buried in saturated sand. These experiments varied explosive charge size, its depth of burial, the target stand-off (SO) distance and target plate dimension. The investigation concludes with a discussion of the accuracy of the numerical simulations when compared with the experimental observations.

Jan 1, 2005

By K. G. Holley

Blasting is usually required to produce easily-excavated broken rock, while leaving surrounding rock masses as undamaged and stable as possible. In mining applications, it is common to utilise production blasting in the centre of an open pit, and specially developed limits blast designs when blasting adjacent to the excavation perimeter. In open pit blasting, limits blast designs generally include pre-splitting, trim blasts, or buffer blasts, all of which are designed to limit, or eliminate, damage beyond the designed pit wall. This paper reports on the findings of a study of the profile of damage in rock masses surrounding blasts, determined by a combination of vibration monitoring, displacement monitoring using extensometers, and video inspection of open holes drilled at various distances behind blasts. The results obtained suggest that the profile of damage may extend for the full depth of the bench, for distances of up to 12 to 15 metres behind blasts. This suggests that entire berms may be affected by blasting, displaying loss of friction and cohesion along joint and fracture planes. The study has considered production blasts and trim blasts with small diameter blastholes and pre-splits.

Jan 1, 2004

Tracer blasting is commonly used in Canadian underground mines for overbreak control. It involves tracing a column of ANFO with a low strength detonating cord. In order to investigate the effectiveness of tracer blasting in perimeter control and to understand its mechanism, a field experimentation was conducted which involved drifting, benching and pipe tests.

Jan 1, 1994

By Brad Johnson

Homestake Mining Corporations' open cut operation at Lead SD. experienced a highwall failure in October of 1993. The failure released a 75' section of rock wall at the 5280' level. It came to rest on the 5200' safety bench. Since work was in progress below the failure, this rock had to be removed for safety.

Jan 1, 1995

By Tom Short, Bill Beam

Some of the weapons testing shafts at Mercury, Nevada require depths of 1000ft and diameters of 10 feet. The top 40 feet to 65 feet is drilled, blasted and excavated by Large caisson type augers in order to provide vertical working room for the placement of large, oil field type, drilling rigs and the required drill collar.

Jan 1, 1991

By Robert Hopler

In use, blasting powder is exploded by a spark from fuse, electric squib or miner’s squib, or by a primer of some high explosive, the last being employed only in heavy charges on open work. In mining, and sometimes in light charges on open work, blasting powder is made into cartridges by means of a paper tube or cylinder sealed at one end, which is known as the Du Pont tamping bag. Sometimes the paper cylinder is made by the miner by coiling a section of heavy paper, known as blasting paper, around a wooden pin, called a cartridge pin, and securing it with what is called blasting soap. The removal of the pin leaves a cylindrical cartridge open at one end, into which the powder is poured and the top folded and sealed with blasting soap.

Jan 1, 2014

By Steve Dillingham

In recent years, there has been a trend toward increasingly demanding blasting standards being enacted by local and regional regulatory authorities. The objective of this paper is to alert blasters of the difficulties that are created for blasting projects as a result of these restrictions, as well as the steps that can be taken to minimize future conflicts.

Jan 1, 1995

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