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By Carl R. Peterson, Robert G. Lundquist

The development of a remotely-controlled drill and blast excavation system is desirable both because it is potentially more economical than mechanical tunneling in hard rock and for safety. A serious impediment to such development is the problem of relocating and reentering previously drilled blast holes to place the explosives.

Jan 1, 1983

By Abraham Lindo

Panama’s current economical growth demands an increase in electric power supply; projected energy supply for 2012 exceeds the demand by as little as 2%. In an effort to comply with the demand, several different hydroelectric projects, promoted by the government, are currently under construction and each of them vary in generating capacity, construction design and complexity.

Jan 1, 2013

By Richard J. Mainiero

Traditional techniques for the experimental determination of toxic fumes produced by the detonation of high explosives are not applicable to blasting agents. To detonate properly, blasting agents require confinement, a significant booster, charge diameters of 3 inches (7.5 cm) or greater, and charge lengths greater than two times the charge diameter. Without these conditions, blasting agents will not detonate at full order, leading to a misrepresentation of the gaseous products.

Jan 1, 1997

By Wang Zhong Qian, Liu Hui

The paper proposed a fractal and damage model for rock-breaking by blasting, which assumed that the process of rock-breaking results from intrincent fractal development and the accumulation of damage. Remarkably, the process is of fracture character. Based on the model, a computer program is compiled to calculate the 3-dimension damage distribution in blasting crater. Trial results agree well with the predicted results, showing the model set up in the paper is sound.

Jan 1, 1997

By Michael J. Sapko, Eric S. Weiss

The U.S. Bureau of Mines has been conducting research on the secondary explosion hazards associated with the mining of oil shale under gassy mine conditions. Explosive incendivity tests have been conducted in a 28 m~3 (1000 ft~3) gallery to evaluate the relative incendivity of experimental emulsion-ANFO blends. The incendivity was measured by determining the minimum inert stemming requirements for preventing the ignition of a methane-air atmosphere by the discharge of hot detonation products from a 5.7 cm (2.25 in) diameter borehole.

Jan 1, 1990

By Daniel Roy, Chris J. Preston, Ron J. Elliott

This paper discusses the use of pressure transducers in water filled boreholes in conjunction with surface mounted geophones to gather field data for in-situ dynamic rock properties determinations. A high speed collector is used to capture the data in the field. The calculated P and S wave velocities and rock density measurements are used as input into the Blastcalc program where the values of Young`s Modulus and Poissons Ratio are calculated. The rock properties information is used along with geological structural data and explosives properties in a 3-D blast modelling program to calculate predicted fragmentation distribution and other blast performance criteria based on the proposed blast design.

Jan 1, 1996

By M S. Sandhu

Singrauli area of Madhya Pradesh in India has been developed as the power capital expected to produce around 11000 MW in near future requiring 65 million tonnes of Coal per annum. Thermal power plants were installed considering the vicinity of coal reserves which are minable by open cast mining methods. Crisis of oil in seventies further expedited the process of planning big open-cast projects in the area varying from capacity of 3 million tonnes of coal to 14 million tonnes per annum. A separate company - Northern Coalfields Ltd. was formed to ensure meeting the rising demand of coal required for energy production. Northern Coalfields at present is producing 35 million tonnes of coal and will reach the capacity of peak demand of 65 million tonnes by the turn of the century.

Jan 1, 1998

By Pierre Allard, Wilfrid Comeau

Near-field and close-in blasting can be safe and efficient, near engineered structures, if the dynamic reaction of structural members to blasting vibrations are considered. Safe particle velocity criteria can be derived from allowable safe static flexural deflections and critical frequencies. Control of close-in blasting can be accomplished using low-pass filtering of the particle velocity signal at the critical frequency. The CETE Mediterranee laboratory at Aix-en-Provence, France, a branch of the Ministry of Roads and Bridges has -pioneered this approach and successfully applied it to major road cuts and tunnels in built-up areas, as well as a major powerhouse expansion project in Africa. This approach is presently being used for a spillway rehabilitation project in Quebec, Canada. This paper exposes- the theoretical aspects and gives case histories of its use. The SCS-15 an automated, peak reading, data acquisition device is described.

Jan 1, 1991

By Satish Kate

Mining of Iron Ore in India is done by Surface Mining methods and most of the deposits are massive and are occurring in Hills, surrounded by green forest cover. While majority of iron ore produced are from mechanized mining systems, some quantities are also produced from semimechanised mines. In mechanized mines, apart from state-of-the-art level of mechanization, the Run-off-Mine ore is subjected to multi-stage crushing, screening and washing/beneficiation, for improving the grade and ensure segregating of different size range. The steel plants within the country have been operating their own captive mines, where both lumps and fines are used in their furnaces. In case of mines, which exclusively supply ores to export market, the lumps produced yield very high price and thus efforts are being made to maximize lumps recovery. The mine, where the author had been associated, is an export-oriented mine which supplies iron-ore to Japanese steel plants.

Jan 1, 2004

By Catherine Johnson, Barbara Rutter

The shock tunnel located at the Missouri University of Science and Technology Experimental Mine is 65 feet 9 inches (20.0406 m) in length. The tests performed inside of this tunnel are either arena tests or shock interaction and transfer (SIT) tests. Arena tests simulate a large open air blast, with lower explosive weights, by elongating the impulse of the blast wave. SIT tests are conducted to determine how the produced shock wave interacts and transfers its energy into a target object located at the end of the tunnel. The target used in this research is multilayered, with each layer being a different material. The targets are 2 ft. by 4 ft. (0.6096m by 1.2192m) pieces of Medium Density Fiberboard (MDF), DOW polystyrene foam insulation, and gypsum drywall. The order of these materials varies with each test. This shock tunnel is unique, because the geometry changes along its length. To fully understand how the shock waves are affected by these changes, a working model was needed. The second purpose of this model is to confirm the maximum charge size of 400 grams (14.11 oz.) of C4 that can be detonated inside the tunnel without causing damage to or failure of the tunnel, thus reducing the amount of time needed in downtime and repair. The model predicts pressures in various locations both within the tunnel and the attached target, thus assisting in determining where failures would likely occur. In the process of generating this model, several problems were encountered, including filling the tunnel with air, meshing the complex geometry, and creating the tunnel in a CAD system. This paper will discuss how these problems were solved. A working model was created by using ANSYS Explicit Dynamics and ANSYS Autodyn. The tunnel geometry file was created using SolidWorks and includes the complex geometry changes along with the target and its mount located at the end of the tunnel. The results produced by the model were compared to the field SIT tests. The comparison of the results from both the model and the experimental testing showed a similar trend in the pressure traces.

Jan 1, 2018

By David E. Siskind

"This report describes recommended vibration monitoring and assessment practices at blasting sites.Intended is regular monitoring, tracking of trends, responding to complaints of alleged damage, and the technical and data aspects of addressing lawsuits."

Jan 1, 1999

By TH Kleine, AR Cameron

Size assessment of fragmentation is all about estimating the population of fragment sizes in the rock pile. A knowledge of the size distribution of particles can be used in applications from evaluating the stability of a waste dump, to optimizing a blast design to achieve a required fragmentation, to on-line control of a crushing and sieving operation.

Jan 1, 1997

By Kirstin Girdner, Vicki Seppala, Tom BoBo, John Kemeny, Mike Higgins

Optimal blast fragmentation is fundamental to all phases of comminution. Changes in blast design may affect efficiency and productivity of downstream processes such as crushing, milling and leaching, resulting in cost savings or losses.

Jan 1, 1999

By Surinder Singh, Vassilios Kazakidis, Damian Gregory

Safety, stability, and functionality of mine excavations depend on the structural integrity of the surrounding rock mass. Various explosives and perimeter control blasting techniques have been developed in order to minimize rock damage associated with the conventional drilling and blasting operations. The success of perimeter control blasting depends on many factors grouped in three categories: rock mass features, blast design and implementation, and explosive parameters.

Jan 1, 2008

By N L. Thomas

Hole size affects many factors which directly influence fragmentation in the muckpile and hence, the cost effectiveness of the entire operation. These factors include production capability, explosives and accessories efficiency and usage and drilling accuracy. In addition, hole size should be chosen to suit the geological conditions. The paper concludes that the optimum hole size is generally the largest that can be used commensurate with production and environmental considerations.

Jan 1, 1986

By Kevin Cole, Dennis A. Clark, F William Laslow

Since 1976, the Metropolitan Sanitary District of Greater Chicago, (MSDGC), has commissioned the excavation of a tunnel system in the Chicago area, hundreds of feet below the surface in solid limestone. This paper outlines the blasting patterns, explosive selections, and monitoring techniques used to assure a satisfactory job completion, following the specifications.

Jan 1, 1982

By Joshua Micah Hoffman, Catherine E. Johnson

The recruitment and retention of future talent into the explosives industry is becoming increasingly important. One potential area from which future talent can be recruited is local student chapters. Many of the student chapters are closely connected with engineering programs. While this makes sense and both entities benefit from these arrangements, there is a trend of job placement primarily in the engineering industry. Before the explosives industry can begin to compete with other industries, it should be determined what is drawing the students into these other fields. The work presented in this paper sought to better understand the collegiate student population from which a portion of future explosives professionals will emerge. This was done through the use of an anonymous online survey distributed to the student members of the International Society of Explosives Engineers, as well as, members of SEE student chapters. The survey contained questions about future job and career plans, ideal job placement, and expectations of salary. The purpose of the survey was to determine what these students expect or require from a career in the explosives industry. This information can help steer recruitment activities and job offers. Through understanding what is incentivizing these students who have accepted or plan to accept jobs in other industries the explosives industry can better posture itself to be more competitive in recruiting from the collegiate talent pool.

Jan 1, 2014

By Conny Postnpaok, Mark E. Hammele

"A major problem that has continued to plague the surface oil industry is blast induced damage to the coal seam. Atlas Powder Company has addressed this situation through several years of field research in full-scale production environments. Many operations across the United States havebeen evaluated ."

Jan 1, 1989

By Stephen Hamilton

This case history details the issues surrounding the rock drilling industry’s growing demand for straight holes, the importance of straight holes and the introduction of a new production drilling systems that can effectively and economically drill a true bore hole. Since the introduction of the hydraulic rock drill, the rock drilling industry has asked for a drilling system that would provide the fast penetration and low operating costs of Top Hammer drilling systems combined, with the directional control of Tube or DTH drilling techniques.

Jan 1, 1999

By Scott Gustfason, Richard N. Snyder

What is a safe stand-off distance? Recent mishaps using conventional blasting equipment have seen flyrock as distant as 3,750 feet from the blast area, or close to three-quarters of a mile, therefore, whether below ground, under water, in surface quarries or at a structural demolition site, data signals riding a radio wave promise a new horizon for the users of both electric and non electric blasting circuits.

Jan 1, 1987