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By James Ballard, Charles H. Dowding

Recent Office of Surface Mining regulations have called for pre-blast surveys of residences within one-half mile of blasting. Unless lighting effects and the multiple origins of cracks are recognized, hurried (lowest bid price) pre-blast surveys may be more harmful than beneficial. Unrecorded, but pre-existent, cracks can be noticed by homeowners during blasting under special lighting conditions. This paper discusses important factors to note during pre-blast surveys, presents data collection forms and discusses the importance of photographic technique in recording cracks (both present and previously patched).

Jan 1, 1979

By Dale S. Preece

A discrete element computer program, DMC (Distinct Motion Code), has been used for several years to simulate blasting-induced rock motion. Recent enhancements of DMC's capabilities have included addition of an algorithm that couples together rock motion and gas flow. This allows the user to specify a particular explosive which also specifies equation-of-state and other parameters necessary to model explosive gas flow from the blastwell. Rock loading by the flowing gas is calculated automatically. The mechanism for calculating the rock loading is the subject of this paper. The rock motion effects the gas flow calculation by changing the porosity. DMC is currently being used on a SUN SPARCstation 2 computer workstation.

Jan 1, 1993

By V Krishna Mohan, J Edmund Hay

This paper discusses the results of the gap sensitivity measurements made on water-gel explosives, sensitized by monomethylamine nitrate (MMAN) and flake aluminium, and one emulsion explosive. This study specifically deals with the effect of the mode of initiation, end or center, on the measured L50 values with air gap and coal dust gap for the above explosives. Similar measurements have also been carried out on a nitroglycerine (NG) - based explosive. The results show that the mode of initiation plays an important role in determining the air-gap sensitivity of these explosives. However, in tests carried out with the coal dust gap, the L50 ( grams of coal dust ) values for these explosives are close in both the types of initiation. The results indicate that the sensitivities of these explosives may be ordered in the following manner: NG-explosive>> Aluminized explosive ~ MMAN-explosive > Emulsion explosive

Jan 1, 1982

By Lee Wehner, Daryl Kin, John Bolger

The Maumee Quarry, located in the city of Maumee, Ohio, has large in-situ cavities, ranging in size from 3 ft (.91 m) in diameter to over 15 ft (4.5 m). The drill/blast team challenge is to drill, load and shoot the geologically disturbed rock in a safe, cost efficient manner, while in close proximity to a commercial area. A continuous improvement process, managed by a Blast Optimization Team (BOT), was implemented to quantify the innovative explosive loading techniques that have been implemented. Borehole camera monitoring, modified loading practices, the need for accurate drill hole logging and open communications between the drill and blast crew proves critical to the success of the operation. Safe Standard Operating Procedures (SSOPs) have been developed and are strictly enforced for the drill/blast cycle. All blasts are monitored with seismographs and recorded on video to provide detailed information as part of the Blast Management Plan. Despite the geological challenges, the measurement of rock fragmentation index versus loader dig rates has provided near optimal crusher throughput.

Jan 1, 2007

By Andrew Ritter, Victor I. Montenyohl, Stephen R. Winzer

Thirty-seven open pit production blasting operations have been monitored using high-speed cameras running between 500 and 7000 frames per second. Analysis of the resulting films reveals irregularities in timing including sequencing errors and crowding (holes firing less than 8 ms apart), confirming results of laboratory testing of ms delay blasting caps (Winzer, 1978). Where blasting parameters are otherwise constant and within recommended guidelines (stemming, spacing, burden, etc.), timing problems dominate the overall performance of the blasting operation. Model tests in layered Homalite 100, designed to simulate joint or bedding planes in rock, indicate the importance of the stress waves generated by the explosive in developing the crack network which is ultimately responsible for the fragmentation seen in the resulting muckpile. These mechanisms are strongly supported by high-speed film studies at Pinesburg, Maryland. Experiments in controlling relief in deep shots (where depth approaches the lateral extent of the bench blasted) using borehole geometry and hybrid initiation systems (electronic timer and pyrotechnic delays) were carried out. The results suggest that the 1 me/ft. of burden guideline developed by Bergmann et aI., 1974 is too short, and that much longer times are necessary to optimize fragmentation and muck digability. Longer times are found to reduce noise, vibration, and flyrock.

Jan 1, 1979

By R Holmberg, C Sjoberg, B Larsson

This paper describes the excavation of an underground naphta storage facility at Stenungsund in Sweden. The main purpose with this paper is to give an overall view of how the excavation was carried out and in what type of bedrock the storage was built. Emphasis has been done to highlight the importance of using cautious blasting to avoid blast damage in the remaining rock. Attempts has also been done in order to evaluate what the degree of Swedish cautious blasting has meant for the rock support costs during the construction period.

Jan 1, 1984

By Chapman Young, William L. Fourney, Richard D. Dick

During 1981 and 1982, an extensive oil shale fragmentation research program was conducted at the Anvil Points Mine near Rifle, Colorado. The primary goals were to investigate factors involved for adequate fragmentation of oil shale and to evaluate the feasibility of using the modified in situ retort (MIS) method for recovery of oil from oil shale.

Jan 1, 1985

By A Lance McAnuff, Robert T. Booren

Construction of a dock facility for the Lake Erie Development Project of Stelco Steel involved underwater blasting in commercial fishing waters near Port Dover, Ontario. The most stringent environmental constraints were imposed and a monitoring program involving water overpressure recordings, using equipment developed specifically for this assignment, correlated with observation of caged fish specimens at various distances from the blast source, was undertaken to determine the effects on fish life and to establish whether a protective air-bubble curtain system should be installed around each blast area.

Jan 1, 1989

By Richard W. Watson, Julius Roth

The Bureau of Mines has recently completed a contract study of the hazards associated with surface mining.! Part of this effort involved an analysis of surface mining accidents associated with blasting activities. For this purpose, 71 reports of accidents investigated by the Bureau of Mines or the Mining Enforcement and Safety Administration (MESA), covering the period from 1962 to 1976, were collected and analyzed. In addition, blasting accident frequencies for the period 1973-1976 were extracted from the central computer files maintained by the Health and Safety Analysis Center (HSAC) in Denver, Colorado. This paper presents a preview of the findings, which are treated in more detail in the final report.

Jan 1, 1978

By H Fukui, K Ichikawa, K Aikou, E Suzuki

An electronic delay detonator (EDD) consisting of a digital-base electronic delay module and a conventional instantaneous detonator module, designed for series connections with a special adjustable-output blasting machine, is described and shown to provide a delay time accuracy some four to twelve times higher than that of pyrotechnic millisecond and decisecond delay detonators, together with the other performance characteristics necessary for practical use. Also described is a blasting design system which allows effective reduction of ground and air vibration, through the use of EDDs with optimum delay times as determined by accurate computer simulation based on wave form and other data obtained from an on-site single-shot test blast.

Jan 1, 1989

By Charles E. Joachim

Railroad and blast induced vibrations were measured in the vicinity of the proposed Big Bend Cutoff. Peak horizontal and vertical particle velocity relations were developed using least squares regression analysis. The dominant frequencies of these data are in the range of 30 to 50 hz. Therefore, allowable charge weight per 30 msec delay curves were generated for buildings (2 in./sec) and unlined tunnels (8 in./sec). A blasting contour map is presented for this site.

Jan 1, 1984

By Lina Lopez, Jose Sanchidrian, Manuel Lopez, Pablo Segarra

Previous work in which rock properties and blasting parameters (geometry, charging and timing) were reported together with truck filling times, is taken as a starting point for a thorough analysis of the influence of the former on the mucking velocity. The experimental set was composed by 11 blasts made in an open pit mine. Non-parametric, distribution-free statistics is applied. The mucking rates (in bank cubic meters per unit of bucket volume and per hour) appear to be clearly dependent on the explosive energy and powder factor, both magnitudes combined as energetic powder factor (energy per unit of rock volume). The mucking rate is a non-monotonic function of such factor in the range of the blasts analyzed. The determination of the function is optimum when the fraction of the explosive below grade is not considered and when the explosive energy is qualified as that delivered at a partial detonation regime. Different types of loaders seem appropriate for different energy levels. At low levels both front loaders and rope shovels obtain small productivities without a statistically significant difference in their performance. At high energy levels, front loaders qualify higher than rope shovels. Mucking velocities can be equally small at low energy powder factors and at high ones if rope shovels are involved.

Jan 1, 2008

By Evan Smart, Andrew Palangio, David Klingspor, Blessing Taiwo

This study presents a DMAIC-based approach to optimize blasting performance and achieve crusher-compatible fragmentation at the Walker-Severn Quarry in Ontario, Canada. By applying the Six Sigma DMAIC (Define, Measure, Analyze, Improve, Control) framework, the study aims to enhance the integration between blasting and primary crushing operations. Several representative blasts will be simulated and evaluated using both aerial and terrestrial image analysis technologies to assess fragmentation characteristics. The investigation was guided by quarry-specific Key Performance Indicators (KPIs), ensuring that blast design modifications were both practical and operationally relevant. Through structured analysis and data-driven refinement of blast parameters, the study reveals how this framework was used to address the quarry production demand for increased crusher throughput, and reduced processing costs. The existing quarry blast design was assessed as a baseline and compared against the crusher's inlet requirements and the acceptable fines level specified by the quarry. This evaluation aimed to identify and implement modifications to enhance blast performance. A drone (UAV) was employed to capture post-blast images and monitor blast pile displacement. These UAV images were used to generate an orthomosaic image, which was analyzed to assess fragmentation. The orthomosaic was overlaid onto a GIS platform using a 10m-by-10m grid to evaluate fragmentation distribution across the bench and identify areas requiring optimization. Additionally, drone imagery was utilized to monitor the impact of each blast on the subsequent blast's free face and to assess energy utilization for optimizing front-row holes to achieve improved fragmentation. The outcomes of this research offer a replicable methodology for continuous improvement in quarry blasting practices, with a focus on producing fragmentation that aligns with primary crusher requirements.

Jan 26, 2026

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 Navid Mojtabai, Jaak J. K Daemen

Some facilities require ground vibration limits that are far below typical vibration levels of interest in most blasting situations. A possibly extreme example of such a facility might be the proposed SSC (Supercollider Super Conductor) high energy particle study system. The applicability of conventional blast vibration predictors for such a low amplitude vibration is highly uncertain. For this preliminary study, a series of field measurements are made, and the results integrated in a set of vibration predictor equations. Ground vibrations induced by blasting operations at one proposed SSC site are monitored at close distances (hundreds of feet), intermediate distances (miles), and long distances (tens of miles) from the blasts. Peak particle velocities are recorded at short distances, ground displacements at other points, as well as frequencies. Theoretical analyses are performed by integrating all data in a variety of ground vibration predictors. From the statistical analysis of the data, ground motions at various points along the ring site are predicted for a given charge weight. The approach taken appears adequate for making tentative estimates of exceedingly low amplitude vibrations at great distances from mine blasts.

Jan 1, 1987

By Charles A. Kliche

The Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA) established a national program for responding to releases of hazardous substances into the environment. The funding mechanism for this program is the Hazardous Substance Response Trust Fund (commonly referred to as Superfund), which provides funding for the implementation of removal and remedial response actions.

Jan 1, 1997

By R Frank Chiappeta, Eduardo Nixon, John Dean Smith, Tom Treleaven

"The creation of the Panama Canal was far more than a vast, unprecedented feat of engineering. It was a profoundly important historic event and a sweeping human drama not unlike that of war. Apart from wars, it represented the largest, most costly single effort ever before mounted anywhere on earth. It held the world's attention over a span of forty years. It affected the lives of tens of thousands of people at every level of society and of virtually every race and nationality. Great reputations were made and destroyed. For numbers of men and women it was the adventure of a lifetime.

Jan 1, 1998

By R A. Farnfield

Measurement of the environmental impact of ground vibration from blasting operations is based almost exclusively on the peak vibration level generated. This measurement is known as the Peak Particle Velocity or PPV. The recorded PPV is used to assess the impact of the vibration both in terms of structural damage and human response. Limits for vibration are almost universally quoted in terms of PPV levels and, as a consequence, blast design for vibration control is centred around techniques for the control of this peak value.

Jan 1, 1996

By Donald D. Eilers, Pharis E. Williams, Thomas O. McKnown

The Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX) system was developed by the Los Alamos National Laboratory for determining the energy released in a nuclear explosion by measuring the position of its shock front as a function of time. The CORRTEX system, fielding techniques, and the methods and software for data reduction and analysis were developed over a 15 year period with hundreds of measurements made on nuclear tests and high explosive experiments. CORRTEX is a compact, portable, fast-sampling, microprocessor-controlled system, based on time domain reflectometry, requiring only a 24 volt power source and a sensing element. Only the sensing element (a length of 50 ohm coaxial cable) is expended during the detonation.

Jan 1, 1995

By Calvin Konya, Theodore R. Myers, Robert Lundquist

The design of a single, large mass blast using ring drilling may take two to three months. This time requirement inhibits the evaluation of multiple designs. It also reduces the flexibility to redesign a blast when a parameter affecting the blast changes. Manual preparation exposes the design of a ring blast to a greater probability of human error. The use of Computer Aided Design (CAD) can help to overcome the shortcomings of manual design preparation. High speed electronic calculation, as well as programming, allow for many designs to be considered before blasting. Parametric programming allows single or multiple parameter changes to be introduced into an existing design, such as changes in drilling equipment, variations in ore density or changes in explosive. Exposure to human error is reduced by programming that performs calculations and produces graphical displays for review by the designing engineer. The goal of achieving desirable fragmentation for the minimum cost, when using ring blasting, is obtainable using blasting design techniques and CAD. Multiple designs can quickly be generated and costed, producing cost curves that indicate an optimum design with respect to cost.

Jan 1, 1990