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By Thomas E. Ricketts

Limited void volume blasting (LVVB) occurs when rock is blasted into a volume that is not sufficient to let the rock expand to its free-bulking value. The freebulking value is obtained when the rock particles have enough space to separate, tumble and rotate to produce the maximum amount of void possible between the fragments when they finally come to rest. Although bulking value depends on particle size distribution and shape, a typical free-bulking value for uniform, finely broken shale is about 1.67. LVVB occurs in almost every type of blasting used in both surface and underground mining operations. For example, in multiple-row bench blasting for surface mining, the final delays that are designed to fragment the rock furthest from the free-face are generally confined by previously blasted rock which results in a LVVB situation. In underground mining, the blasting is automatically confined and is commonly done intentionally to limited void volume to reduce mining cost and improve safety. LVVB primarily affects rubble bulking and thus the excavation of the broken rock which is related to the productivity and economics of a mining operation.

Jan 1, 1989

By Leslie Taylor, R. Reed Skagga, William Gault

The ultimate aim of our overall task, of which the effort described in this paper is a part, is to be able to model the impulsive output of buried charges and the response of targets of interest. It is not practical or cost-effective to determine the response of all targets of interest to buried charges of all sizes by testing them. In order to have confidence in our models, however, they must be validated by a modest number of tests. A critical element in modeling the response of a target is the ability to model the loading function. The load a buried charge applies to a target above it when the charge detonates can be characterized in terms of the vertical impulse. The vertical impulse is a function of the size of the charge, its depth of burial, and the properties of the soil in which it is buried. The primary objective of the effort described in this paper is to determine the load a known charge places on a non-responding target so the data can be used to validate our models.

Jan 1, 2005

By Ray Jambakhsh, John Okell, Frank Cook

"In early 1988, an experimental study was carried out at the Inco's McCreedy West Mine inLevack, Ontario. The objective was to develop blasting techniques which would allow themine to maintain production targets and reduce blast induced vibrations and overpressure.Due to its close proximity to the town of Levack (approximately 900 feet), particularconcern was expressed as to the vibration and overpressure resulting from the undergroundblasting operations."

Jan 1, 1993

By William C. Lane

The Pacific Northwest has an abundance of seamy, coarse granite and basalt rock. It is used primarily for road construction. Small quarries are opened nearest the road work to cut the cost of hauling. The crushers are portable. Small diameter holes 2 1/2" to 3 1/2" are placed close together to insure proper fragmentation. It is not unusual to load and shoot 100 to 700 holes 40' deep.

Jan 1, 1986

By L. L. Oriard

he Metropolitan Water District of Southern California (MWD) supplies water to some 16 million people in a semi-arid region. Most of this water is imported. Some of the supply lines cross over the San Andreas fault, one of the most notorious and active faults in the U.S. There was a serious need for emergency water in case normal supplies should be interrupted. To fill that need, MWD had to find a reservoir site on the west side of the San Andreas fault, west of the mountains. Because of the distinctive nature of the location, it was necessary to construct a huge “bath tub” by building a dam at each end of a valley, requiring some 115 million cubic yards (88 million cu.m) of fill. In effect, two large-scale surface mining operations have been under way simultaneously. The $2.2 billion project is known as the Eastside Reservoir Project. Because of space limitations, this paper will be limited to those topics which are expected to be of primary interest to explosives engineers, principally related to large-scale rock fill production. There is not sufficient space to discuss the many diverse geotechnical questions related to site selection, geological and geophysical field testing, laboratory testing and design considerations. This brief overview may assist those who might be interested in making a tour of the project site following the ISEE conference.

Jan 1, 2000

By Raymond Hofstetter, Paul Worsey

The purpose of this paper is to investigate commonly used methods for mitigating the effects of shrapnel from linear shape charges (LSC) used in the demolition industry. Primarily the problem is not that shrapnel poses a threat to human bystanders, but rather it can affect the other charges in the demolition or damage to structures in close proximity to the charges. This research aims to determine what methods have success at stopping shrapnel, what methods do not, and to promote an awareness of the dangers of using the LSC without any protection. The project was carried out at the Experimental Mine site at the Missouri University of Science and Technology. This research is an undergraduate research project to fulfill the requirements for the Explosives Engineering minor program at MST.

Jan 1, 2008

By Dr. Anurag Agrawal, Steve Franklin, Clint Zimmerman, Elijah Williams

In a time when data has become a highly valued commodity within many mining and quarry operations, managing large amounts of current and historical information can be difficult. If not managed properly, trying to leverage the data to make informed operational decisions promotes another challenge. Geographic Information System (GIS) is an environment that uses computers and software to create, manage, analyze, and map all types of data. Currently, the mining industry is faced with a challenge to produce the demanded critical metals and minerals that drive our economies. GIS is leveraged in many large mining industries today to help drive decisions, save cost and plan for future operations. Specifically in the Drilling, Blasting and Quarrying industries, data is being captured at many different levels, whether it is a subsurface geological, blast performance, quarry surveys, loading and hauling, or crushing performance. Pen and paper logs and reports compiled lack the dimension that GIS can bring for extracting value from real-time or historical data. GIS connects data to maps, integrating location data with all types of descriptive information. Paired with Artificial Intelligence, additional analytical layers can be built on platforms to extract data and automate workflows. Having the ability to encompass several forms of collected data to drive operational decisions can bring huge savings to the bottom-line. This paper will dive into the areas where GIS data can drive value into operations by assisting in the management and analysis of the types of data being captured, specifically with Drill and Blast. Whether it is tracking haul road conditions, monitoring locations of equipment, environmental conditions, quantifying blast performance or developing a quarry plan based on geological models. GIS can collectively encompass all of this data to bring tremendous value to the operations, improving safety, efficiency and production.

Jan 21, 2025

By Dr. Kyle Perry, Ryan Sibley

Rock blasting is an inherently difficult field to quantify independent & dependent variables and the specifics of how the energy interacts with the material for a number of reasons. Independent variables such as geology are innumerable and stochastic, thus, on a laboratory and full-scale basis these variables are assumed to be homogenous across the desired rock boundary. Dependent variables are difficult to quantify in the laboratory based on the specific aspect of the fracture mechanisms that caused the fracturing. The same variables are difficult to quantify in the field because of the shear amount of material being blasted. The energy interactions with the material are difficult to quantify due to the rate of the reaction and the lack of quantification of independent variables. The second main issue with laboratory scaled rock blasting is the nature of the small form-factor explosives required for use in a scaled setting. These explosives that are utilized, traditionally PETN detonating cord, have a greater ratio of potential energy converted to shock energy rather than gas energy when compared to traditional field explosives, such as emulsion or ANFO. Research over the past decades has indicated that gas pressure has the greatest contribution to rock blasting performance, such as fragmentation and material throw. The factor of varying ratios of energy production has not been discussed in any of the reviewed publications. Publications discuss dimensionless scaling, dynamic similitude, and length-based scaling, however, none of these scaling methods discuss the ratio of energy production. The main focus will be correlation of energy production ratio of shock versus gas to dependent variables. This paper analyzes previous publications within rock blasting and related field as they pertain to scaling procedures and will highlight the similarities and differences in the various publications and detail the observed omitted variables that possibly lead to skewed data.

Jan 21, 2025

By Jorge Cardenas, David Martinez

Blasting-induced vibrations can be predicted with high precision, allowing for the optimization of sequence design, delay timing, and charge configurations to minimize their indirect impact on rock masses. This optimization leads to a reduction in peak particle velocity (PPV) and dominant frequency at monitoring points. However, a crucial aspect of slope safety is estimating the degree to which vibrations influence stability through numerical modeling of the dynamic response. Slope stability is closely linked to rock mass strength, the predominant failure mechanism based on discontinuity orientation relative to the slope face, and the pre-existing stability conditions before dynamic alterations occur. Blocks, wedges, and planar failures tend to slide under lower vibration levels and are more susceptible to resonance, particularly in fractured and low-strength rock masses. To evaluate the interaction between rock mass and vibrations, photogrammetry and artificial intelligence were employed to identify discontinuity families at vibration monitoring sites. This data facilitated the development of artificial discontinuity networks (DFN), which replicated a discontinuous medium within a numerical finite element model. The input signal was recorded at the slope base using triaxial geophones and incorporated into a discontinuous numerical model. The output signal was estimated through finite element analysis and subsequently compared with geophone measurements taken at the same location. Based on real-world output signals, damping parameters and the model’s natural frequency were adjusted to align both frequency spectra. Using the calibrated parameters, vibration records from various blasting projects at different distances were applied as input signals until slope failure was induced, thereby defining maximum allowable vibration limits in terms of PPV and frequency at the monitoring point. This approach provided a framework for optimizing sequence designs, charge configurations, and delay timings to enhance slope safety and prevent failure due to blasting-induced vibrations.

Jan 26, 2026

By Thomas E. Lobb, Harry C. Verakis

Blasting is a primary means of extracting minerals and ores at surface mining operations. The domestic consumption of explosives and blasting agents during the year 2001 was about 5.25 billion pounds. Flyrock is always a major concern for the blaster. Flyrock from surface blasting operations has caused serious injury and death to employees and other persons. Injuries due to flyrock and the lack of blast area security accounted for over two-thirds of all blasting-related injuries in surface coal, metal, and nonmetal mines during the period 1978-2002. Selected accidents due to flyrock and lack of blast area security in surface mining are presented in this paper. Incidents related to construction blasting are also described. Techniques to mitigate blasting accidents are discussed. These include proper blast design, driller-blaster communication, inspection prior to loading and firing the blast, removing employees from the blast area, controlling access to the blast area, and using a blasting shelter. An experienced driller could detect potential problem areas such as voids, mud seams, incompetent rocks, and other irregularities by observing the progress of drilling. The drill log should include the details of any unusual or exceptional circumstances noticed during drilling. A blaster may need to alter the loading configuration to alleviate potential problems. Basic blast design is sometimes taken for granted and assumed to be proper for the conditions encountered, but one size does not fit all. It is known from the physics of blasting that the explosive energy takes the path of least resistance. The path of least resistance could generate flyrock, depending on the blast site conditions. A combination of ‘borehole tracking’ and ‘laser profiling’ can assist in improving the design of a blast. The blaster can use these tools to adjust borehole loading to match site conditions.

Jan 1, 2004

By James Ludwiczak

This paper consists of the conduct of a forensic criminal investigation of the components, construction, use, and functioning of two suicide bombs. As the title states, the task was to form professional opinions as to whether the bombs would work, would cause property damage, and would injure or kill. The bombs were created and installed by a defendant in a Federal death penalty case where the defendant’s daughter was killed in a shootout with the West Virginia State Police. The two black powder bombs were placed under the front seats of the defendant’s automobile and were designed to function by the use of a toggle switch connected to the automobile’s cigarette lighter. The forensic work first consisted of an inspection of the remains of the wiring system and bombs at the Bureau of Alcohol, Tobacco, and Firearms Laboratory, in Ammendale, MD. This was necessary to determine and detail the wire diameter and lengths, the lengths and size of the wire used, the type of toggle switch used, the type of containers, the type of rocket motors used to initiate the black powder, the manufacturer and amount of black powder used in each bomb, and the type, wraps, and amount of duct tape used for the construction of each bomb. Using this data, tests were conducted by duplicating the wiring system and the two bombs to insure that the system functioned properly. Each bomb was duplicated and initiated to observe the violence produced when initiated in the open air. Duplicate bombs were placed under the seats of a similar type of automobile and initiated. The purposes of the tests were to duplicate the bombs, to observe the violence of the initiation, and to observe the damages to the automobile produced by the initiation.

Jan 1, 2007

By Pierre DePasquale, Ricardo Chavez

Lowering of quarry energy consumption participates to answer both environmental and financial issues. The “EE-Quarry” European project, supported by the European Commission (EE stands for Energy Efficient), develops a new and highly effective modelling and monitoring Energy Management System technique to improve Energy Efficiency and move to a low CO2 emission rate in the nonmetallic mineral industry. Within this global quarry project, blast design, as the first link in the chain, has to be optimized in order to satisfy requirements of downstream operations. The authors have been developing and implementing an operational methodology using continuous field measurements and field adaptation methods for blast design. It drives the drilling and blasting work, aiming at a more energy efficient and environmentally friendly operation. Based upon actual local conditions (rock-mass assessment, face geometry, borehole deviations, etc.), blast patterns are optimized through a specific hole-by-hole blast design software. It provides a better and more consistent energy distribution, to achieve a better rock fragmentation, while avoiding explosive overconsumption. The software also calculates total energy inputs and the drilling and blasting contribution to Greenhouse Effect. Coupled with methodical fieldwork and variable density explosives, it has been leading to a real reduction in energy costs and greenhouse gas emissions. As the project is now reaching its final stage, demonstrations were conducted in various quarries around Europe. Several simulations were carried out and compared to the site data, in order to propose enhancements for the different phases (extraction, loading, hauling, crushing and transport) while bearing in mind the environmental impact of the quarry. This blasting methodology allows to assess the carbon footprint of drilling and blasting in conjunction with the downstream operations, thus to evaluate the global carbon footprint of quarrying. Copyright ©

Jan 1, 2015

By Steven Townend, Don Wadden

In today's global economy the need to stay competitive is essential for commercial survival and growth. To this end Inco is committed to continuous improvement in its operations. Various aspects of the mining process have been examined to find ways of improvement.

Jan 1, 1994

By Gerald R. Coonan

Laboratory research is being conducted to substantiate suggested levels for voluntary standards on human response to transient vibration. The application of those findings to actual field conditions, however, will be limited because they will not include social and psychological factors existent in the real world. It is necessary, therefore, to examine available empirical information on complaints in an attempt to define the influence social and psychological factors might have on the laboratory results.

Jan 1, 1982

By Salah A. Taqieddin

The blast casting technique of removing overburden is an innovative technique which was successfully used in the mining of certain surface coal and quarries. This method was found to be efficient in minimizing the labor and equipment cost while accelerating mining operation with safety. This method was successfully applied to horizontal as well as to dipping coal seams. Also it was practically applied to single as well as to multiple ore bodies

Jan 1, 1992

By Scott G. Giltner, Alex Schwenk

An iron operation sought to extend the life of the mine by conducting a major pit pushback in an area close to several public structures and the neighboring town. The result of the pushback would make millions of tonnes of ore available for mining allowing many additional years of taconite mining. This paper discusses the initial development blasts conducted for the pit pushback. For the development blasts, it was determined that no fly rock should leave the mine site and that the blast vibrations should be as low as possible, but specifically under 19 mm/s (0.75 in/s) at a nearby sewage treatment plant. One issue complicating the blast design was the variation in hole depth within any given blast. For the initial sinking shot, the hole depths varied from 6.4 m (21 ft) to 12.5 m (41 ft). In the subsequent blasts the hole depths within each blast could vary up to 5.8 m (19 ft). Various tools were employed to design the blasts to ensure there was no fly rock and that the blast vibrations were as low as possible. UAV surveys of the blast areas were conducted to provide a 3-D representation of the free faces and bench surface. The 3-D point cloud produced from this was used to measure the shape of the free faces. Once the shape of the free faces was quantified, it was possible to establish proper placement of the crest holes and develop a custom explosive load for each blast hole. In addition, signature hole analysis was performed for each blast to determine the optimum delay time that balanced the need for minimal vibration, prevent fly rock, and a well fragmented muck pile. Electronic detonators were applied to achieve the necessary control of the blast that balances these three concerns. The results of the seven blasts conducted to date provided the desired results. The peak vibration level at the sewage treatment plant for the seven blasts was 10 mm/s (0.40 in/s). The only fly rock occurred when there was a miscommunication in the blast design resulting in under burdened holes on the front row. To date, the mine has been able to safely expand the pit into an area that will add many years to the mine life. The muck piles have been well fragmented with reports from the shovel that they have all dug well.

Jan 21, 2025

By Rob Grant, Manuel Lopez Cano, Mike Briggs, Ken Fletcher

The scorched desert sands and life giving waters of the River Nile in Egypt have been the back drop to awe inspiring engineering feats for over 4,700 years. The latest engineering marvel to grace the land of the Pharaohs is the Mubarak Pumping Station Project at Toshka. This ambitious project aims to open up an area of 607,000 hectares (1.5 million acres) of barren desert to irrigation based farming with the supply of 29 million tonnes (32 million tons) of water per day, drawn from Lake Nasser on the river Nile. It is anticipated that this currently unpopulated area of southern Egypt will soon flourish and become home to several million Egyptians who will conduct their lives around the water supplied by the 230 kilometers (144 miles) of concrete canals. An integral part of the pumping station is the intake canal. The canal was excavated in two sections – the dry excavation, and the wet excavation. The wet excavation comprised of some 5.5 million cubic meters (7.2 million cubic yards) of rock to be drilled, blasted, and excavated, from the surface of the lake. The challenge at hand was how to achieve this safely, quickly, and cost effectively, with water depths of up to 45 meters (148 feet), excavation depths of up to 47 meters (154 feet), blast production rate peaks of up to 30,000 bank cubic meters (39,200 bank cubic yards) per day, blistering summer air temperatures up to 60°C (140°F), and security concerns about the storage of large quantities of explosives in the Middle East region. The solutions to these challenges were engineered by UEE Explosives and centered around the use of a microgel bulk explosive called Rioflex™ and an international team of engineers and operators from three continents. The microgel and accompanying pumping system allowed pumping rates of up to 17,400 kg (38,400 lb) per day, and more importantly, enabled the bulk product to remain as an oxidizing matrix whilst in transport and storage, transforming into an explosive only moments before being pumped into the blastholes. This case study outlines the underwater drill and blast process employed at the Mubarak Pumping Station Project at Toshka, and the novel solutions to the unique challenges encountered.

Jan 1, 2004

By Yang Ruilin

Bulk gassing technology is a growing trend in the commercial explosive industry. The gassed bulk products produced differ from microballooned bulk products or cartridged products. It is easy to know the loaded or in-hole density for microballooned bulk products or cartridged products, whereas it is not as straight forward to know the m-hole density for gassed bulk emulsions. The loaded density is one of the key parameters affecting explosive performance and therefore it is important to have a field technique to monitor the in-hole properties of gassed bulk products in order to accurately predict the blast performance and to ensure efficient use of the products.

Jan 1, 1999

By Tristan Worsey, John Rathbun, Andres Malone

A run of mine, low grade gold heap leaching operation is currently looking to increase ounce recovery by decreasing run of mine fragmentation size. Current blasting practices have resulted in an average fragmentation size of 80% passing 7.05 inches (179 mm). It is estimated that a decrease of 2 inches (51 mm) in the 80% passing fragmentation size has the potential to yield up to a 2.5% increase in the overall life of mine recovery within this ore body. This potential recovery increase could lead to an increase in recoverable ounces which, in turn, would lead to a better profit margin. As this particular deposit is composed of predominantly low grade heap leach the capital investment in a crushing facility was cost prohibitive, it was therefore decided to look into the current blasting practices as a means to improve fragmentation.

Jan 1, 2015

By Tom Hale

Developers and blasters are faced with increasing public demand and regulatory restrictions to maintain the lowest possible levels of noise and vibration from blasting operations in populated urban areas. Pyrotechnic products have proven to be a low noise, low vibration alternative to conventional blasting for close-in rock excavation and concrete demolition applications. Pyrotechnic breaking charges often yield 1/10th the vibration and noise compared to traditional explosives, and have been demonstrated to increase public confidence and decreased damage potential where they have replaced explosives, thus allowing new opportunities for work and greater job profitability. This paper presents a practical approach to utilizing pyrotechnic products in various applications including trenching, mass excavation, demolition, and dimension stone production, providing methodology for pattern design, vibration probability and loading calculations. Field research data is reviewed and compared to conventional explosives.

Jan 1, 2008