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By M V. Van Bers, A L. McAnuff, A Curic

During the Summer of 1997, rock excavation was carried out for construction of the Centre Block Underground Services building (CBUS) abutting the most historically significant structural complex in Canada, the Parliament Buildings in Ottawa. Controlled blasting was required for the removal of 25,000 cubic metres of limestone bedrock within the ten week time window of Parliamentary recess. A test blast program carried out in 1996 had established that close blasting was viable even within the very restrictive limits considered necessary to preserve the structural and cosmetic integrity of these historic structures. In total 300 blasting operations were required to complete the excavation, including the 20 test blasts conducted in 1996. Based on attenuation characteristics established for the site during the trial blast phase, the blasting contractor proposed excavating the CBUS site in three zones. Each zone contained differing drill patterns, depths and explosive loads. Vibration intensities, air concussion levels and displacements across representative existing cracks were measured and recorded at numerous observation points within and around the Centre Block and the Library of Parliament, as well as on the grounds of the Parliamentary Precinct. The blasting portion of the excavation was completed within budget in less than eight weeks, well within the tune window available. Comparison of very extensive pre and post-blast condition surveys revealed no damage to the existing structures on Parliament Hill as a result of these operations.

Jan 1, 1999

By Daniel Castelo, Ben Potter

This paper will discuss the most efficient and effective way to use shape charges when considering standoff distances and the amount of an explosive to be used. For each shape charge test that was performed, a one inch diameter copper liner of 90o was used. Different standoffs for each shape charge were tested to see which one would penetrate the deepest into rolled homogenous armor steel (RHC 44). It was determined that a standoff of three cone diameters provides the deepest penetration. In addition to testing for optimal standoff distances, the effects of overfilling as well as under filling a shape charge with explosive was tested against a shape charge with the bare minimum amount of explosive for correct detonation. These “fill” tests were all performed at a standoff of three cone diameters. Overfilling has little to no effect towards penetrating deeper into a target while under filling a shape charge has an effect of shorter penetration. C-4 explosive was the main explosive for all shape charges.

Jan 1, 2011

By Vitor Fonseca de Barcelos, Jair Carlos Koppe

Our society is experiencing a digital revolution. Technology is demonstrating its significant potential for mining industry. In this paper are presented the measured and estimated impacts of applying new technologies on blasting operations in a copper mine.

Feb 1, 2020

By R. F. Favreau, Patrice Favreau

"Ever since we have started to assist those responsible for blasting with blast simulation studies, we havebecome aware of an interesting aspect, namely that in 90 % of cases we are asked ‘‘Can you seek ablasting method which gives better fragmentation than the method which we use now’’. But after a visit to the site, and the evaluation of the fragmentation obtained with their present blasting method, it very often becomes evident that it is the ease of mucking and not the fragmentation which requires improvement. Hence we then proceed to do a simulation study the results of which are improved mucking rather then more fragmentation, and those responsible for the blasting always become very satisfied."

Jan 1, 2017

By Thomas Pallua, William C. Gates

"Two major railroad companies have identified several segments along the railroad corridor betweenTehachapi and Bakersfield, Kern County in California that require construction of a second track to improve operations in this area. The total project proposes an upgrade of five segments along the Tehachapi-Bakersfield route. The authors focused on two segments: Walong to Marcel and Cliff Siding Extension. The second track project comprised design of a through-cut adjacent to an existing tunnel and up to 120-feet-high (36m) side-hill cuts (both in granitic rock). The authors characterized the geologic ground conditions and ground behavior, including rock mass quality and strength using a combination of rock core drilling and rock slope mapping. The rock mass is generally characterized as granitic tonalite with strong core stones surrounded by a matrix of decomposed granite (DG)."

Jan 1, 2017

By J. P. Proulx, Richard O’Meara, Ruilin Yang

A blast optimization project was carried out at an Open Pit Metal Mine using the Multiple Blasthole Fragmentation (MBF) Model and the Multiple Seed Waveform (MSW) blast vibration model. The aim of the project was to optimize rock fragmentation of the ore blasts to significantly increase metal recoveries while keeping the blast vibration levels at the highwall under control. The project also examined the blasts in the waste rock using the Fragmentation model to expand the blast pattern and select economical explosives for drill and blast cost savings while minimizing any adverse effect on the dig rates. Two sets of near field signature blasthole tests were conducted in both hard ore and relatively soft waste rock. The information from the near-field signature blasthole vibration was used as input to both the MBF and MSW models, as site specific geological information interacting with blasting. The implementation of the full blast design is also input to the MBF and MSW models. A production blast for each rock type was monitored for blast vibration and rock fragmentation. The full blast information and the blast results are used to calibrate and validate the models. The Fragmentation and Vibration model were established for the two rock types at the mine. At each site the Fragmentation modeling was conducted in parallel to the Vibration modeling to ensure blast vibrations were under control while the rock fragmentation was improved. The Fragmentation MBF and MSW are each an integral part of the blast optimization tool. Various scenarios using different explosives, hole delays and blast patterns were modeled for rock fragmentation and blast vibration. The recommendations from the modeling project were to be field trialed at the mine. The implementation of the recommendations was expected to help the mine significantly in terms of the mining economics, and high wall stability and safety.

By L D. Lawrence

Certain blasting applications are more prone to the generation of significant levels of nitrogen dioxide post blast fumes, more commonly referred to as after blast smoke, generally ranging in color from dark yellow to bright red. This paper reviews basic background chemistry defining the observed fumes and attempts to correlate geology, blast design, and explosive composition effects on the level of nitrogen dioxide that can be observed in various blasting conditions. Additionally, a test setting for evaluating the generation of post blast fumes is presented with pertinent test data detailing generic explosive formulation modifications which effect the overall level of post detonation generation of nitrogen dioxide.

Jan 1, 1996

By Brian Sandhuas, Robert McClure

All flyrock incidents have the potential to result in injuries or fatalities that can result in loss of company reputation, license to operate with clients, and bear the exposure to high cost liability. From 2007 to 2009, one North American Quarry and Construction Business experienced a series of flyrock incidents. In the spring of 2009, this business declared that the frequency and severity of Flyrock Incidents had reached an unacceptable level. A Flyrock Elimination Program was launched.

Jan 1, 2012

By Steve Kane

Lightning is a very real problem in the surface mining industry. Today, as adverse market conditions continue to influence the surface coal industry, it has become necessary that all functions of the surface mining process become as efficient as possible. High production with reduced manpower is the winning combination of staying competitive in the market place. We at AMAX Coal are committed to staying in the coal business, but we have always been committed to providing a safe work environment for our people and will continue to do so in the future. Approximately two years ago, our Midwest mines installed state of the art lightning detection and warning systems at our mines. This paper will cover its application at Delta Mine; the benefits and problems encountered, and the impact this system has had on Delta Mine.

Jan 1, 1992

By Eric Roller, Elliott Giles

All flyrock incidents have the potential to result in injuries or fatalities that can result in loss of company reputation, license to operate with clients, and bear the exposure to high cost liability. From 2007 to 2009,one NA Quarry and Construction Business experienced a series of flyrock incidents. In the spring of 2009, this business declared that the frequency and severity of Flyrock Incidents had reached an unacceptable level. A Flyrock Elimination Program was launched.

Jan 1, 2012

By Joshua Hoffman

The recruitment and retention of future talent into the explosives industry is becoming increasingly important. Student chapters help with this effort but what are they doing and are there things they could learn from each other? This paper discusses the University of Kentucky Student Chapter's efforts to grow membership, retain its recruits, and integrate them into the explosives industry. Several social and professional events during which the students are able to meet and network with members of their future industry are introduced. The special relationship that has been fostered between the University of Kentucky and Missouri University of Science and Technology is discussed. Professional development initiatives which are critical for a student to become vested in the industry are shared in this paper. These opportunities which range from internships to research positions allow a person to get a better understanding of the explosives industry and find the niche that best suits them. 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. By providing these students with the chance to learn more about the explosives industry and get hands on experience more of these future engineers and professionals can be retained after their graduation.

Jan 1, 2013

By Nathan Rouse

This blast mitigation study examined the effects of a barrier wall on explosively driven pressures. This area of blast mitigation is of interest due to the many different applications involved in protecting a target from an explosive attack.

Jan 1, 2012

By William Hissem

When we look out on our business landscape today, the words higher, faster, fdwther come to mind. Compliance issues, business integration, increasing production and profitability demands are converging in an age old industry and giving it a new twist. Not that the rock changes, rather that as the variables of our business change, the resulting “cut-off grade in business” turns ore into rock or rock into ore. The trick is to emphasize the latter. As with the miners of yore, what was recovered from the business enterprise had a lot to do with tools and skill. So it is today. When the casual observer looks at drilling and blasting operations today, many see the same basic offering in terms of equipment types and process. Looks, however, can be deceiving. As with the aviation sector, a given machine might took similar to previous generations of equipment, but in fact is radically different in terms of power, efficiency, accuracy, and range. So it is with hydraulic top-hammer drills today.

Jan 1, 2000

By Denis Rickman, Jon Windham, Stephen Akers, Byron Armstrong

The soil crater formed by detonation of an explosive charge is of considerable military interest because of the common use of explosives to create soil obstacles. The soil crater is also an important piece of forensic evidence for the investigation of terrorist bombings. With recent advances in numerical codes, modeling and simulation of explosively-formed soil craters is becoming an attractive means of analyzing this phenomenon. Consequently, the need exists to better understand the relationship between soil properties and the resultant soil crater. An extensive database has been developed for the case of explosives detonated in or above in-situ soils of various types. However, in most cases, the soil properties were either not adequately quantified or the soil materials themselves varied such that the gross properties were poorly understood. A research program is underway to improve methods of relating soil crater dimensions to soil identification properties such as USCS classification, particle-size distributions, and Atterberg limits, as well as to soil composition properties such as density, moisture content, and volumes of solids, water, and air. As part of this effort, both explosive detonations conducted over well-controlled and well-documented soil backfills and companion numerical simulations were studied. This paper presents an overview of the effort.

Jan 1, 2010

By Nikolaos Petropoulos, Ulf Nyberg, Daniel Johansson

A series of signature boreholes were blasted to observe any difference between confined and free face blasts. Four geophones were used to capture the compressive wave. The conventional approach, i.e. the calculation of vectorized peak particle velocity (vPPV) did not show any difference. Also a wavelet transform was tested.

Feb 1, 2020

By Mohammed Alkazimi, Katie Grantham

The purpose of this paper is to quantify the risk to both the environment and surrounding infrastructure from a pipe sealing implosion. Both accuracy and the precision in determining how a submerged infrastructure damaged by underwater explosions performs provide better decision-making capabilities for managers facing impending oil spills. This determination is vital, especially for both emergency and crisis management teams, as categorized consequences based on both the nature of the structural layout and the surrounding marine environment assist in identifying whether or not the utilization of this technique is applicable. Thus, the decision maker’s aim, in a crisis, is to minimize any associated risk that might result in aggravating the situation by endangering both the infrastructure and marine life. Therefore, the resulting risk matrices will enable technical personnel who are not experts in explosive technologies to be armed with the information necessary to determine if this mitigation technique is applicable to their situation.

Jan 1, 2013

By VIVEK KUMAR HIMANSHU, Murari Prasad Roy, Kaushik Dey, Rakesh Kumar Singh, Ashish Kumar Vishwakarma

Sublevel stoping is commonly adopted method in underground hard rock mining. Proper planning and its execution is the key requirement for stope extraction using this method. The stope extraction has been a challenging task since decades. The major reason being the unavailability of free faces as compared to open cast bench blasting. The geological and geotechnical parameters changes gradually even within the stope itself. So the blast design parameters should be planned according to the scenario of upcoming ring. Blast design parameters like burden, toe spacing, inclination of blast holes, diameter of blast holes, charge density of explosive etc plays an immense role in rock damage. For the proper breakage of rock, the movement of burden is prime objective. To study this, explicit dynamic based modeller of M/s Ansys was used. The burden values were varied from 20-65 times diameter to assess optimum burden value during the study. The models were simulated for the rock having 35 MPa uniaxial compressive strength and 102 mm blast hole diameter. Altogether three holes were blasted having hole depth 14-14.5m. The blast design parameters and respective blast induced ground vibration has been measured at the experimental site. Core sample of the rock of experimental site has been used for the evaluation of geotechnical parameters. These geotechnical parameters were inserted into the simulation model. The volume of rock excavated along free face has been calculated in each model. It has been found that the burden value can varies from 35-40 times blast hole diameter (3.6-4.1m) to achieve greater volume of rock along the free face for 102 mm blast hole diameter and rock of 35 MPa uniaxial compressive strength.

Feb 6, 2023

By Mark Bosse

This is a paper demonstrating the use of a fixed wire and trolley system to deliver 2 or 5 lb cast primers (with 2 meter cap/fuse assemblies) deep into avalanche terrain. This avalanche terrain is mitigated using explosives prior to being opened to guests.

Feb 1, 2020

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 Per-Anders Persson

TIGERWIN, now on CD, is a user-friendly personal computer code (running under Windows) which determines the detonation and expansion state of an explosive from its known chemical composition. TIGERWIN is intended for users in the mining and commercial explosives industry who do not routinely program or run Fortran codes. The code allows the user to open a window on the computer screen and enter the initial density and the weight percentage composition of an explosive, ingredient by ingredient. Alternatively, the code can balance the composition with one or more ingredient percentages fixed, while proportionally adjusting the others automatically to give a total of 100%. The equation of state and its parameters can be user-selected from several proven and tested versions of the BKW, the JCZ, and the ideal gas equations of state. TIGERWIN allows the user to select several options for different additional calculations, such as determining the constant volume explosion, the Chapman-Jouguet (C-J) point, the detonation Hugoniot, the expansion isentrope from the C-J point, and point calculations with selectable specific volume and temperature. Additional options include calculations of detonation data with one or more ingredients partially reacted, assuming either temperature equilibrium between reaction products and unreacted material, or keeping the unreacted material “cold” at the initial temperature. Thus the code can run both ideal and non-ideal detonation calculations. The code automatically saves the input and output files in a separate directory for future reference. The output from several calculations can be displayed and printed in the form of a comparison table. In it, the key results of up to five calculations with different explosive compositions can be compared. The results from an individual calculation can be displayed graphically and printed with expansion work, pressure, or temperature as functions of specific volume. A complete listing of the details of the calculation results, similar to those from the original Fortran Tiger calculations, can also be displayed and printed. No computer experience is required to run the code and workshop participants are encouraged to bring in their own formulations to try out on TIGERWIN

Jan 1, 2000