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By A. K. Sirveiya

A major concern with blasting at surface mines is generation of ground vibration, air blast, flyrock, dust & fume and their impact on nearby structures and environment. A study was conducted at a coal mine in India which produces 10 million tonne of coal and 27 million cubic meter of overburden per annum. Draglines and shovels with dumpers carry out the removal of overburden. Detonation of 100 tonnes of explosives in a blasting round is a common practice of the mine. These large sized blasts often led to complaints from the nearby inhabitants regarding ground vibrations and their affects on their houses.

Jan 1, 2005

By P D. Katsabanis, K Steeves, D Dombrowski

Accurate electronic detonators with firing time accuracy within 100 microseconds of the nominal have been used to control blast results in terms of fragmentation, vibrations and wall control. Axisymmetric experiments and experiments utilizing small benches have been conducted in order to calibrate a numerical model under development and examine the influence of delay interval on wall control, fragmentation and vibrations. The results obtained so far indicate definite advantages of precise timing in reducing back break and wall damage. Fragmentation is affected by the delay interval and high speed film observations and measurements indicate that the delay interval should allow the damage zone from each blasthole to be fully established prior to the detonation of the next borehole. Studies on vibration control demonstrated that vibration synthesis work using signature shots can only be of use if accurate delays are employed.

Jan 1, 1995

By George Young Mosteller

This paper is summary of the practical solutions developed in the excavation of drilled piers (caissons) at GPCo's Plant Scherer, Juliette, GA. Plant Scherer is a 3,245 Megawatt Fossil Fuel Powerhouse and, when completed, will be one of the largest fossil fuel plants in the Southeast.

Jan 1, 1980

By Thomas H. Kleine, Alan R. Cameron, William W. Forsyth

In general the software required by a blast designer includes tools that graphically present blast designs (surface & underground), can analyze a design or predict its result, and can assess blasting results. As computers develop and computer literacy continues to rise the development of and use of such tools will spread.

Jan 1, 1995

By R. Franfield, W. J. Birch, L. Bermingham

Previous researchers have put forward two different theories as to the origin of air overpressure from quarry blasting. In 1980, Siskind et al postulated that the initial face movement gave rise to the displacement of air and that this resulted in the air overpressure pulse. However in 1990 McKenzie et al carried out research that indicated that the air overpressure pulse came into being as consequence of the shock wave created by the detention of the explosive charge in a blast hole, rapidly propagating through the rock and then impacting on the quarry face.

Jan 1, 2013

By Michael K. Phang, Thomas A. Simpson

Field studies at an underground mine site were conducted to evaluate and monitor blast-induced vibrations on an underground coal mine roof. The vibration data were evaluated so that a suitable damage criteria or guidelines from which a safe operating distance between surface blasting and underground mine operations can be established.

Jan 1, 1984

By U Nyberg

Peak particle velocity (PPV) and distance measurements from a single-charge blast test conducted by Swedish researchers in iron ore at the Kiruna Mine in northern Sweden are presented. They are used along with theoretical PPVs calculated using an equation based on hydrodynamics to determine a damage distance range caused by a single charge. This equation, which relates PPV to explosive properties, charge geometry, and distance from a charge, was then applied to a charge of different geometry that was used in drift rounds. A comparison between calculated and measured PPVs suggests that the stoping holes likely damage the easer hole locations, and the easer holes produce damage to the perimeter hole locations. The practical effect is that typical damage limit predictions based on measurements conducted in fresh or undamaged rock are conservative. This suggests that even when perimeter control is not exercised in drifting (i.e., the perimeter holes are fully loaded), the resulting damage may be less than normally expected due to the wave damping effect of the pre-damaged rock. Due to the damping effect, poor perimeter blasting practices are somewhat self correcting. However, it must be strongly emphasized that well-engineered blast designs with perimeter control are highly beneficial in relation to both economic and safety aspects.

Jan 1, 2011

By Thomas Leonard, Philip R. Berger, Bryan E. Papillon

Bardon Trimount Inc., a large producer of aggregate, crushed stone, and concrete, was experiencing significant public opposition to its five quarries in the Boston area. It was believed by the authors that this opposition could be significantly lessened if the total number of blasts per week were reduced. Although the blasting company at these quarries, Austin Powder Company, contended that this could easily and safely be accomplished by increasing the size of the blasts, regulations precluded this alternative by limiting the total amount of explosives that could be used per blast.

Jan 1, 1996

By Gungor Tuncer, Ali Kahriman, Umit Ozer, Abdul Karadogan, Mehmet Aksoy, Ertugrul Kaya, Deniz Adiguzel

This research was performed on the quarry that will be opened to produce aggregates and rock filling material at Catalagzi region at Zonguldak providence. Excavations will be done by drilling and blasting. However, there are some structures which can be adversely affected by blasting at the quarry. These structures are a methane exploration drill hole and a house at the distances of 340 m and 390 m, respectively. The one of the main goals of this study is to perform a preliminary assessment of possible damage effect of ground vibrations induced by blasting on these structures by risk analysis based on ground vibration measurements.

Jan 1, 2009

By Dworzak, Andrzej Biessikirski, Jozef Pyra

During the detonation process 20-30% of the energy is being consumed only on the quarrying pro-cess. The remaining amount of the energy generates harmful effects such as: shock wave, acoustic wave, fly rocks and ground vibrations. The ground vibrations effect is the most dangerous especially to structures which are situated nearby an open pit mine.

Jan 1, 2015

By Edward J. Jr Walter, Edward J. Walter

The vibration problem is approximately fifty years old. The original investigation of the U.S. Bureau of Mines was begun in 1930. Significant investigation into the problem was done by Crandell, Langefors, et al, Edwards and Northwood, and again by the Bureau of Mines. This resulted in an effective Safe Limit standard expressed in particle velocity as 2.0 inches per second.

Jan 1, 1979

By Michael S. Wieland

This report discusses measurement techniques utilized in and trend results obtained from research on delay blasting malfunctions in underground coal shots at the U.S. Bureau of Mines. Charge malfunctions occur during delay blasting in underground or surface mines, rendering the explosive operations more hazardous and less productive. Modern instrumentation techniques reveal several types of reduced charge performance, resulting from cross-hole interactions. Two receptor (wave-target) charge malfunctions were detected in fourteen shots that were undeniable. There were other receptor charges that exhibited under-performance by registering out-of-tolerance or noticeably reduced detonation rates. Delay blasting generates tremendous shock waves and rifting forces that fracture and heave the surrounding stratum and unfortunately damage remaining unfired charges. This report contains two graphs, representing roughly 1% of total records, that show donor (wave-source) charge shock waves and rift (reaction-to-heave) compressions. These debilitating wave impacts precipitate modes of reduced charge performance ranging from weak detonations or misfires to sympathetic detonations. As recognized from previous research, impaired charges react poorly, perform less useful work, and yield fumes with atypical higher toxicity.

Jan 1, 1995

By Albert G. Funk, Gary M. Thornley

The available energy of aluminized ANFO and aluminized slurry blasting agents has been measured by seismic methods, calculated theoretically, and compared. With aluminized ANFO it is concluded that aluminum concentrations should be restricted to less than 10 percent because of diminished energy yields at high aluminum concentrations. However, with aluminized slurry it is concluded that efficient use of aluminum can be made at aluminum concert"rations up to 18 percent. It is further concluded that the difference in efficiency of use of aluminum by these two classes of blasting agents results from a higher contribution to useful work from the condensed detonation products of the relatively higher density aluminized slurry blasting agent.

Jan 1, 1981

By Corry Goumans

The job location is at Bear Lake Hydro Project located north of the town of Sechelt, British Columbia, Canada

Jan 1, 2013

By Yoshihiro Moriyama, Toshihiro Okitsu, Ryouichi Banno

The fracturing composition using the gas pressure generated by the thermit decomposition reaction gives the following performances.

Jan 1, 1995

By Chuck Kliche, Bill Clements

This paper relates some of the experiences, good and bad, of blasting adjacent to residences of the primary author during his 15+ years of field blasting in the Northern Great Plains region. During this highly-rewarding blasting career, the author has become aware of two major issues in residential blasting: 1) What we call “Risk/Reward Ratio.”Some questions that must be asked by the blaster prior to taking on any blasting job include: - Can we eliminate or minimize the risk? - Is the reward worth the risk? - Do I have a measure of “nervous confidence” about the shot? 2) Public Relations. Two key elements to public relations are: - Notification - Education All the education in the world to the adjacent populous of what’s happening, of blasting in general, or of what to expect from the blasting does little good without notification. Good public relations is a key to controlling the cost of liability in a litigious society.

Jan 1, 2009

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 B Mohanty, R Yang, M Leblanc

A total of 33 blasts in the pillar recovery program at INCO-Crean Hill has been investigated by means of an extensive set of diagnostic techniques. These included, borehole deviation measurements, stope cavity survey, near-field seismics in both rock and backfill, in-hole VOD and fragment size analysis. The 200 mm diameter VCR blasts employed a variety of explosives types (ANFO, slurry and ANFO/Polystyrene) and deck sizes. The objective of the investigation was to control dilution and backbreak through optimal choice of explosive type and charge weight, without exceeding vibration limits in the adjacent backfill or causing significant degradation in fragmentation.

Jan 1, 1995

By Robert L. Martin, Brian W. Stump, David P. Anderson, David Gross

In an attempt to better understand the impact that large mining shots will have on verifying compliance with the international, worldwide, Comprehensive Test Ban Treaty (CTBT, no nuclear explosion tests), a series of seismic and videographic experiments has been conducted during the past two years at the Black Thunder Coal Mine. Personnel from the mine and Los Alamos National Laboratory have cooperated closely to design and perform experiments to produce results with mutual benefit to both organizations. This paper will summarize our activities, highlighting the unique results of each.

Jan 1, 1997

By W. J. Birch, R. Farnfield, G. D. Rangel-Sharp

It is widely recognised that complaints from members of the public relating to blasting operations are related to both ground vibration and air overpressure. It is also known that a complaint is more likely to be generated if the person is inside of a structure at the time of the blast. Reports relating to such complaints often refer to ‘noise’ inside the structure with terms like ‘rattling’ commonly being employed. Such acoustic response is widely perceived within the blasting industry to be directly related to high levels of air overpressure although there appears to have been very little research carried out specifically related to this effect.

Jan 1, 2007