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By Abdel Rahman, M. Khaled, Abo Makarem

There are four large limestone quarries, located nearby Cairo metropolitan. Drilling and blasting operations are used to extract limestone for the cement industries. In these quarries, the blast vibration should be kept below a certain limit. One of these quarries is Tourah Portland Cement Company (TPCC) limestone quarry which, lies near important and historical large caves, within Tourah Mountain. Therefore, control of blast vibration level becomes very critical.

Jan 1, 2007

By T Michael LeBlanc

Drill trajectory deviation is a recurring problem in vertical retreat stoping operations. As a result of this deviation, 60 kilogram (165 millimetre diameter) and 103 kilogram (302 millimetre diameter) explosive charges are routinely detonated beyond ore/waste contact zones. Consequently, there follows a reduction in finished stope wall stability and an increase in ore dilution.

Jan 1, 1996

By Curtis Garner

Griesemer Stone located in Springfield, Missouri has supplied aggregate in Southwest Missouri since 1946. In 1954 the decision was made to mine the formation and utilize the mined out area for warehouse space. As advancement proceeded, entrances and small diameter air shafts for ventilation were needed and had to be added. It was decided in 1989 to sink an 8' diameter air shaft designed to move 200,000 cubic feet of air per minute with the help of (4) four 50,000 CFM Loren Cook Fans.

Jan 1, 1991

By S B. Richardson, N T. Moxon, A C. Torrance

In many mining situations the energy released by an explosive is far too high and results in over fragmentation and excessive damage to the surrounding strata. Laboratory experiments have demonstrated that the shock energy of an explosive can be significantly reduced by surrounding it with an attenuating material such as a foam. The effect of this reduction in shock energy on fragmentation has been determined using model materials. A four fold reduction in the amount of minus 8mm material relative to an air decoupled charge of the same weight was obtained for a foam attenuator.

Jan 1, 1989

By Paul Muehl, Roger Lawrence

The massive sculpture taking place on Crazy Horse Mountain in the Black Hills of South Dakota, may Be the most unique application of precision blasting techniques in the world today, It is certainly the largest sculpture in history. And it is being carved not by the usual artist implements, but by engineering of explosives. This paper presents a review of the blastingasting techniques and challenges of blast earring the largest sculpture in the world,

Jan 1, 1991

By Adrian J. Moore, Alan B. Richards, Rob Evans

Air and ground vibration from blasting is influenced by the delay pattern that is used. Wavefronts from blastholes fired in a blasting pattern can combine in certain circumstances to give increased blast vibration levels. A simple computer model has been developed which shows the combined effect of wavefronts from a multi-hole blast and identifies if wavefront reinforcement occurs, and permits delay patterns to be designed which will avoid or reduce wavefront reinforcement.

Jan 1, 1994

By L D. Lawrence, W B. Sudweeks, J Bailey

Modern era urbanization is presenting at least one category of explosive consumers with a growing concern for ecological and environmental problems associated with their blasting processes. The construction industry is now, more than ever, being closely monitored with regard to its use of high explosives. In particular, contractors excavating the countless thousands of miles of various trench lines required for virtually every major new construction development taking place in America are being more closely scrutinized by local, state, and federal authorities with regard to blasting practices.

Jan 1, 1988

By G E. Exedaktylos, Y Zhou

The complex and non-linear nature of blast fracturing has restricted common bract design primarily to empirical approaches. The code developed for this investigation simulates the pattern of interacting radial fractures from an array of blastholes, at various burdens and spacings, and in simultaneous and delayed modes. The resultant pattern is analyzed and a fragment adze distribution calculated.

Jan 1, 1989

By Michael E. Curtis

This paper outlines a study performed to analyze the advantages of utilizing a blasting agent with a velocity of detonation that is 1.3 to 1.4 times the P-wave velocity of sedimentary shales and sandstones at a major Midwest coal operation.

Jan 1, 1997

By William B. Lee, James J. Jurmu

The Cleveland-Cliffs Iron Company operates three open pit iron mines on the Marquette Iron Range of Michigan's Upper Peninsula. Open pit iron ore mining began in the area in the 1840's. Underground mining was predominant from 1860 through 1960. Large scale low grade-open pit iron ore mining began in the early 1950's with the establishment of the Humboldt Mine, concentrator and pelletizing plant. This pit operated until 1970, when the reserves were exhausted.

Jan 1, 1986

The use of angled shot holes can be extremely effective in blasting faces that either have a great deal of toe burden or where it is difficult to give a drill access to a face due to backbreak and face erosion. However many quarry operators are wary of using angled holes because of the perceived possibility of increased flyrock and uncertainty of the driller's abilities to drill at the designed angle.

Jan 1, 1994

By Lee W. Saperstien

Section 709 of Public Law 95-87, "Surface Mining Control and Reclamation Act of 1977," requests the National Academy of Sciences to determine if the standards of the act are applicable to minerals other than coal. The Academy has established the Committee on Surface Mining and Reclamation to respond to this charge. The committee is, itself, organized to be responsive to the varieties of minerals, environments, mining systems, and locations that are representative of U.S. mining systems. It is not the charge of the committee to write trial legislation, but to indicate whether or not technology, extant or proposed, is available to meet the standards of the law, and at what cost. It is within this set of conditions that the committee will examine blasting.

Jan 1, 1979

By Kazuyoshi Kawami, Fumihiko Sumiya, Kunihisa Katsuyama, Yuji Ogata, Koichi Kurokawa, Yuji Wada

When explosives are detonated in the borehole where there is an air gap between the explosive charge and the borehole of inner wall, the shock cave in an air gap travelling ahead of the detonation front sill be generated. This shock wave is called the precursor air shock wave (PAS). The explosive is precompressed by the PAS, and as a result of that the detonation failure occur on occasion. This phenomenon is well known as channel effect.

Jan 1, 1994

By Tom Hanke, Joe Strobbe

The 80 year old Theodore Roosevelt Dam built in a scenic canyon near Globe, Arizona is currently undergoing a major renovation. The old stone dam, built by hundreds of skilled stonemasons, is being covered with a new concrete face that will increase the dam height by 77 feet. The renovated dam will improve flood control and provide increased electrical power and recreation area. The contractor, J.A. Jones is constructing the new dam and powerhouse for the Bureau of Reclamation.

Jan 1, 1993

Blasting is a very cost effective method of rock fragmentation but its uncontrolled application often results in excessive damage to the perimeter of an excavation. Several perimeter control techniques are available but tracer blasting is commonly used in Canadian underground mines for overbreak control. This involves tracing a column of Ammonium Nitrate-Fuel Oil (ANFO) with a detonating cord. In order to investigate the techno-economic effectiveness of tracer blasting in perimeter control, a field experimentation was conducted which involved blasting in sublevel caving and sublevel sloping operations, experimental drifting, benching and pipe tests.

Jan 1, 1997

By Steven V. Crum, David E. Siskind

In response to its own concerns and those of the public, industry and regulatory agencies, the Bureau of Mines is studying the impacts of low-frequency blast vibrations on structures. Previous research has identified potential problems associated with low-frequency ground vibrations and also found that their existence was not particularly rare, given large surface mine blasts and certain geologic conditions. Only a limited amount of data existed in the blast vibration literature on structure response to ground-vibration frequencies below 6 Hz.

Jan 1, 1993

By Philip Barnhard, Lyman G. Bahr

By recording the arrival time of a pipe wall at evenly spaced intervals in a plane perpendicular to the pipe axis, application of the equations of motion permits calculation of the pressure of the explosive acting to accelerate the pipe wall. Data observed from various non-ideal explosives are presented, together with values of pressure to be expected from thermodynamic calculations.

Jan 1, 1981

By Kenneth K. Eltschlager, Richard R. Brochu

At the International Society of Explosives Engineers Annual Conference held in Nashville, Tennessee in February 1995, a Seismograph Standards Committee was established. The purpose of this committee was to develop objective performance specifications for vibration measurement instrumentation and field use practices. It was also understood that due to geology, temperature, and moisture in the soils, it is not possible to design and build an instrument to give results which are absolutely comparable for ground vibration. It was, however, considered essential to standardize instrumentation by which vibration can be measured under closely defined conditions so that results obtained by users of seismographs are always the same within stated tolerances.

Jan 1, 1999

By Dennis Dobson, Keith M. Henderson

Lone Star Industries, Inc. in Cape Girardeau, Missouri operates an open pit mine to produce limestone for its portland cement manufacturing plant. The present mining method, for safety and legal reasons, requires a set back from the property line, a berm, sloped overburden, and vertical rock walls with catch benches.

Jan 1, 1997

By Kaby K. Kabongo

The paper is drawn from a project intended to explore a technique of prediction, control and optimization of fracture in coal induced by blasting. It evaluates the fines generated in coal submitted to dynamic loading stresses in an impact stamp mortar. The aim is to analyze a complex phenomenon of coal response to blast-generated stresses from a series of discrete simulations of shock and gas actions in controllable processes.

Jan 1, 1995