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By Terry L. Cook

RAG Coal West, Inc., Belle Ayr Mine is located in the heart of Wyoming’s rich Powder River Basin coalfield. Belle Ayr utilizes an open pit, truck/shovel operation to strip the overburden off the 70’seam of sub bituminous coal. Our excavation capacities consist of a 301 Marion with a bucket size of 52 cubic yards, and a 4100 XPB P&H with a capacity of 76 cubic yards. Production levels on these machines are closely monitored utilizing the Modular Mining Dispatch system. RAG Coal West, Inc. is a coal mining business that utilizes the effectiveness of teams as one of their strategies. Technicians have a certain amount of control over their own Team Process. The Drilling & Blasting Team is an assortment of blasters with varying experience levels. We have been able to think outside of the box when it comes to certain “proven” methods of blasting.

Jan 1, 2004

By Frank Barker

Mining operations present a very different environment to the suppliers of explosives, initiating systems and services, both on surface and underground. Typical hazards include underground movement, air quality, ground stability, moving equipment, and the use of explosives. As contractors to the mining industry we do not have management control over the environment in which our people operate. The hazards and consequent level of risk that our people are exposed to in some mining operations are significantly higher by orders of magnitude than in a normal factory environment. Orica Explosives (and other Explosives suppliers) are continually and increasingly identifying opportunities to partner with customers by adding value through the provision of services leading to a reduction in total mining costs. These services include the provision of a bulk underground loading services, delivery of product into underground magazines, magazine management, value added blasting, conversions, rock-on-ground contracts, and blast management programs.

Jan 1, 2000

By Gungor Tuncer, Erhan Bakirci, Ali Kahriman, Atilla Ozmen, O. Nuri Ucan, Savas Gorgun

There are several methods for demolition of structures but most of them depend mostly on conventional ways of using machines for breaking and crushing structural elements. However the need for lots of work force, expense and extreme amount of time for demolition, made most of these methods non-popular nowadays. Therefore, trials to accomplish a more economic and less time taking method lasted with the use of blasting. By applying controlled blasting on a suitable structure, the structure can collapse and break down to pieces in very short period of time, with no extra work force and cost. In spite of advantages of explosive demolition, the potential danger of explosives and the damage that the blasting may cause to surrondings, if not controlled properly, made people timid to the method especially in urban areas. Therefore, the pre-assumption by computational analysis has become an essential matter in the process.

Jan 1, 2002

By Lawrence C. K Hu

The release of load mechanism during rock breakage by explosives was founded by Dr. T. N. Hagan & published at the Sixth International Colloquium on Gasdynamics of Explosions and Reactive Systems Stockholm, Sweden, 1977.

Jan 1, 1995

By Garfiansyah Rayes

In 2023, an Indonesian coal mine experienced significant contamination of an emulsion blend explosive by dynamic mud and water flow, triggered by flooding due to exceptionally high rainfall. This intrusion into explosive columns compromised the stability and efficiency of blasting operations, thereby impacting overall mining productivity. The extent and impact of these contaminants on the stability and performance of the emulsion blend explosive were rigorously analyzed through a robust assessment methodology that included comprehensive field measurements and controlled laboratory experiments designed to replicate the challenging site conditions. Utilizing a combination of theoretical calculations and Computational Fluid Dynamics (CFD) simulations, this study evaluates the kinetic interactions between dynamic mud flows and emulsion explosives within drill holes. The methodology integrates Torricelli’s theorem for velocity assessments and Darcy’s Law for understanding the penetration mechanics of mud into the emulsion blend. CFD simulations are further correlated with actual blast data to assess discrepancies between theoretical predictions and real-world outcomes. Results demonstrate a significant reduction in the velocity of detonation (VOD) of the explo-sives, traced directly to mud contamination levels, which align with the quantified penetration rates in the study. Practical measures for mitigating such contamination are proposed, including the reinforcement of water-ways, culverts, and bund walls at drilling locations based on validated simulation data. Additionally, rec-ommendations for operational adjustments during high rainfall events are discussed, aiming to enhance blasting safety and efficiency. The paper concludes by suggesting future research directions towards the development of more resilient emulsion formulations and enhanced predictive modeling techniques to better forecast the impacts of en-vironmental variables on explosive performance in mining operations

Jan 21, 2025

By Geff Gordon, Dale Nies

Small diameter borehole blasting can be very efficient and cost effective. As residential development continues to expand, many areas are now requiring blasting for site preparation and upgrading old utility systems or constructing new ones.

Jan 1, 1990

The underwater explosions have been used for several decades for the determination of energy content of explosives. This test method is the only one by which shock, fly rock and total energy can be measured separately. It enables to develop the energy content of explosives for different purposes; the military high explosives should contain more shock energy whereas the fly rock energy is very important feature for the blasting explosives. The purpose of this study was to establish a test place for the underwater experiments in an old water filled open pit, to estimate the repeatability of the energy measurements, to calculate the standard deviations and to compare the total energy content of commercial explosives to the theoretical values calculated by the thermo dynamical program. The test method seems to work quite well especially for the homogeneous explosives. The difference between the energy content of theoretically calculated and measured values for the homogeneous emulsion explosives was about -3% and for the dynamite about -5%. The energy difference for the unhomogeneous ANFO was detected to be -19%. The diameter of the charge was 15 cm and it was obviously too small for ANFO to detonate ideally. On the basis of the test results this test method seems to fit best for the cap sensitive, completely homogeneous, spherical charges whose masses are big enough and which are initiated from the centre of the charge. The underwater explosions as a test method is the only one which can separate shock, bubble and total energies from each other and therefore makes it possible to develop the properties of explosives for different purposes which is very important feature of this method.

Jan 1, 2005

By Martin Chenoweth

The Metropolitan Water District of Southern California (MWD) is undertaking one of the nations largest water management projects. The Eastside Reservoir Project is being built to insure a supply of water to Southern California in the event of earthquake damage to the aqueducts supplying the region. An 800,000-acre-ft lake will result from the three dams, closing off the valley between two parallel ridges. The single largest contract of the project, the West Dam, was awarded to the joint venture of Atkinson Construction Co., Washington Construction Co. (Morrison Knudsen Co.), and HB Zachry Co. Over 50 million bank cubic yards of rock must be drilled and shot on this contract alone. AWZ relies on the TechBASE database management system for documenting drilling and blasting. The database format of TechBASE allows all production parameters to be linked to the location of the activity. This allows parameters such as drill penetration or boulder production to be analyzed for geologic trends that can either be exploited or dealt with. Shot locations are stored as 3D polygons in a polygon table. Production and cost data are stored in flat tables. Shot names are unique and link the polygon table to the flat table. This allows typical database queries to be made by date, location, cost or any production parameter. The output from these queries can be presented in table, graph and as map formats. The map output is particularly helpful in quantifying geologic conditions and blast performance. The ability to transform the data into information has been very helpful. The ability to present this information graphically has been invaluable.

Jan 1, 2000

By Ed O'Connor, Per-Anders Persson, Manhong Zhou

This chapter deals with the concepts of shock waves and detonation waves together, because a detonation wave is really a shock wave, supported by the explosive reaction that the shock wave ignites and propagates as it travels through the explosive material. In the context of rock blasting, furthermore, there is justification for treating shock waves and detonation waves together, because the mechanical effect of the detonation in an explosive in a drillhole in rock is propagated and its effects are spread throughout the surrounding rock by means of a shock wave. The overall performance of an explosive in rock blasting or any other application is of course dependent on how much thermal energy is released in the chemical reaction that occurs when the material detonates, and on how much useful mechanical work the reaction products can do as they expand. A major portion of this chapter deals with the prediction and measurement of explosive performance, a subject which is now still in a process of rapid development.

Jan 1, 1997

By Tapan Goswami, Michael Croucher

At Bayswater Colliery various methods of controlling highwall stabii were investigated. The use of presplitting was trialled and its effectiveness measured. The presplit hole spacing and explosive charge were based on those succes& lly used in other coal mines in the Hunter Valley. The major presplit design parameter to be determined was the stand-off distance between the presplit line and the back row of the production blast. This could not be transfmed directly from other sites due to the difference between the Bayswater’s production blast geometry and geology to that of other sites. Using highwall face surveys and Orica’s SUR..YPlus@ software, the average back-break behind normal production blasts was determined. This was then used to select the stand-off distance between the back row production blastholes to the presplit line. While presplit designs are normally based on powder factor (kg/m2), the use of energy factor (MJ/m2) was also investigated as a possible design criteria.

Jan 1, 1999

By F O. Otuonye

Full-face blasts were fired in a 12 x 8 ft drift of an underground hardrock mine in a basalt formation with porphyry copper to study the effects of drill pattern and explosive type on the size distribution of the resulting muckpile. Each muckpile produced by five full-face blasts was sampled four times with a scooptram equipped with a 5-cu yd bucket and the size distribution of the broken rock in each bucket was determined by screen analysis. Results show a strong dependence of the fragment size distribution of muckpile on the blast pattern and explosive type for a given rock type. The mean fragment size of the broken rock was compared with the predictive equations of other investigators. Random sampling of the muckpile from full-scale blasts and screen analyses of the samples are recommended in assessing the size distribution of the broken rock because of scaling errors that are inherent in full-scale blasts when designed from results of small-scale tests.

Jan 1, 1985

By Sharon K. Reamer, Klaus G. Hinzen

A series of controlled seismic experiments was performed in a limestone quarry in southern Germany to study seismic effects of cylindrical charges fired in both a half space (HS) (burden 63 m) and quarter space (QS) (burdens of 3 and 3.5 m) geometry. Charge columns contained from 20-32 kg of explosives and initiated from the bottom. The explosives formed a cylinder 4 m (20 kg) and 5 m (32 kg) high and 90 mm in diameter at depths from 3-8 m below ground level. Prior to each of the larger explosions, small charges of 0.12 kg seismogelit were fired at 4 m and 8 m depths in the same boreholes. Seismograms were obtained from 23 three component surface stations and up to 10 three component borehole stations (6 m depth). For each experiment, stations were located on three linear profiles of length 72 m at different azimuths from the source and one semicircular profile at a constant range of 30 m.

Jan 1, 1991

By Alexander S. Escalante, Luis R. Ramirez, Nelson A. Arostegui

Research, analyze, discuss, design, and build an electric oven to perform one of the quality control tests the fanel or common fulminers to determine what temperatures they can detonate at. Give practical applications, conclusions, recommendations and bibliography.

Feb 1, 2020

By Jung-Hoon Ryu, Chang-Ha Ryu, Byung Hee Choi, Yang-Kyun Kim

Control of overbreak in tunnel blasting is one of the key factors affecting the construction expenses as well as safety. Overbreak causes an increase in the cost of construction by requiring an additional amount of shotcrete. In addition, blast damage to the final rock face may cause instability and rock fall hazards. For these reasons, controlled blasting is an indispensable routine in tunnel excavation in order to get a smooth face and to reduce damage to the final wall. We have experienced a very poor quality of excavation depending on the tunneling sites although a similar design of controlled blasting technique was applied. Field experiments over 40 rounds were carried out to investigate the cause of the poor results in tunnel blasting. In this paper, discussed are the parameters affecting the overbreak and some findings from the field experiments. Overbreak could be controlled considerably by adjusting some parameters before the efforts of developing a new blasting method.

Jan 1, 2004

There is an intuitive tendency to equate rock strength with rock stability, yet the two must be evaluated separately. A slope in strong hard rock is not necessarily stable, nor is a slope in weathered weak rock necessarily unstable. In some cases the reverse is true, depending on the geometry of joints and weak planes. The time element is a matter of special concern, that is how suddenly the failure begins and how rapidly it progresses. Sudden failures can be catastrophic, whereas creep usually is not. In soils and weathered rock, the process is usually incremental and is more likely to give some warning of impending failure. With careful observation, the failure process in these materials can be detected and monitored instrumentally or visually. In some cases, the slope may be stabilized, reinforced or modified. When that is not possible, there is usually enough time on this type of slope to remove men and equipment from the area before complete failure occurs.

Jan 1, 1996

By H Leonard Mangum, Victor C. Bryan, Dan McCutchen

Recently there has been an unprecedented marketing effort to promote the advantages of various non-electric initiation systems. This activity has probably been influenced by a major manufacturer's decision to discontinue electric detonator production. Subsequently, distributors of explosive materials, rather than introducing new electric detonator brands, are emphasizing the use of existing non-electric systems. In many cases, such methods fill the need of explosive users in the quarry industry. However, the use of any initiation system should be based on performance, rather than the bent of the market or convenience to the supplier. This analysis is an evaluation of the performance of non-electric systems with emphasis on double trunk line and loop (redundant), as compared to precise electric detonators in use by Martin Marietta. Redundant non-electric detonators, even though more costly, offer the most reliable method of non-electric initiation. However, state-of-the-art precise electric detonators give the best overall performance, except in an environment involving extraneous electricity.

Jan 1, 1990

By Bradley C. Paul

Similar rock formations exhibit great variability in resistance to fragmentation during crater blasting. This observation was made during an attempt to calibrate the Kuz-Ram blast fragmentation model for crater blast geometries used in a modified in situ mining method for copper. The KuzRam equation is used to predict the fragment size distribution from blasting and includes a term called the "rock factor" to account for the fragmentation characteristics of the material. A data base of field scale crater shots in oil shale was available to supplement more limited data on copper ores. First, the blast geometry terms of the Kuz-Ram formula were modified to fit field data with various crater blast geometries. Rock factors were chosen to center the predicted curve on the curve representing observed fragmentation. Next, five possible sources of variability in rock factor were investigated: the grade of the oil shale, the aspect ratio of the charge, the type of explosive, the charge depth, and the rock itself.

Jan 1, 1989

By John Wright

During June and July 1999 a United States Antarctic Program (USAP) team of three commercial divers and one blaster successMy removed an underwater rock obstruction which interfered with safe docking practices of research vessels that call at Palmer Station - the USAP research facility located on Anvers Island, Palmer Peninsula Area, Antarctica. Ordinarily, such a project might be considered routine. However, certain aspects of the project, particularly those dealing with logistics in a remote corner of the earth, sat3eguards for marine biota, and working underwater in the dark of the austral winter, conspired to make this project interesting. Even more challenging was ensuring the protection of the existing pier - a deeply corroded sheet pile structure backfilled with loose gravel and rock - which lay less than 50 feet away from the target obstruction, not to mention uncertainties at the outset as to the nature of the rock mass forming that obstruction.

Jan 1, 2001

By C M. Deosthale, V N. Pangal, M N. Rao

New Mangalore Port is the most important port in Karnataka State, on the west coast of India on Arabian Sea. It handles export of iron ore, granite, coffee, spices etc and imports of crude oil, fertilizers etc. Since 1991, after economic liberalisation by the Government of India, the exports and imports at this port got a boost. Hence the Port Trust felt the need to increase the draught by about 3 to 5 meters for access to bigger ships. In response to a global tender in 1995, the Dutch Dredging Company got the contract to remove 30,000 cu.m of hard granite bed rock, covering 28,000 sq.mtr. area for the Turning Circle and oil Jetty. The operations of drilling, blasting and dredging were to be carried out to deepen the area to about 15 m draught without affecting the normal trade at the Port. This was a time bound contract to avoid interruption by severe Monsoon rains.

Jan 1, 1999

By Claude Cunningham

Simple bulk energy rating of explosives obscures the realities of how these deliver their energy, and diverts attention from the key question of controlling blasting results. Explosive performance is directly related to the pressure pulse impacting on the blasthole wall. This is helpfully visualised by comparing the adiabatic expansion plots for explosives of interest on the right scales and axes. The simple comparison of a pure emulsion with pure ANFO illustrates the practical significance of the intrinsic behaviour of these opposed formulations, showing that the emulsion can be expected to work more by softening rock, while ANFO will tend more to crack it. The explanation for these differences lies in the high shock, low sustained pressure of the former relative to the latter. The technique is readily applied, if a good detonation code is available and able to swap data into a spreadsheet. Any differences between codes will emerge most strongly in comparing the gamma plots.

Jan 1, 2002