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By Paul Worsey, Braden Lusk

Differences exist between public perception of construction blasting and quarry blasting. In general, people are able to tolerate short term inconveniences much better than long term ones. The paper focuses on the public perception of quarry blasting in St. Charles County, MO. This expanding urban environment has seen new legislation targeting preexisting quarry operations that have been in place for many years. A survey was made comprising interviews conducted to gauge perceptions of persons with varying demographics. Interviews covered topics involved with quarry blasting and its reporting methods. The purpose of the interviews was to determine public perception of blasting and how best to report results of vibration measurements. The use of different, less technically complicated measurement scales for vibration and airblast was considered as an alternative reporting system. The question for the industry is, “Has our past haste in adopting complex scientific scales and units been detrimental to us?” In other words, are we reporting the correct things? For airblast, the decibel scale was evaluated against millibar in the public eye. Peak Particle Velocity was also compared to that for displacement. Current legislation in the county is based on complaint levels rather than damage criteria. The complaints most likely not only come from ignorance to the affects of blasting on structures, but also sparse understanding of the units used to report these affects. The past practice of treading softly as an industry has been proven to be a poor choice, and education of the public as well as lawmakers on all levels is necessary. The Mississippi Valley Chapter of ISEE has begun to conduct seminars to this end. One educational seminar has taken place for officials and lawmakers in the St. Louis area, and others are in the planning stages. The focus of this paper is to gauge perception of the damage criteria reported today, and locate focal points for future education of the public in rapidly expanding suburban environments.

Jan 1, 2005

By Robert Jacob Cefalo

In 2019, the Bingham Canyon Mine, owned by Rio Tinto Kennecott Utah Copper Company, mined through the active underground that dewaters the pit. The active underground required the limitation of vibrations to avoid catastrophic damage or damage that would require work to the shotcrete and additional roof support. The surface design of the current sector was mined next to and through portions of the active underground.

Feb 1, 2020

By Italo Onederra, Miguel Araos

"In order to characterize non-ideal explosives, the explosives industry rely on unconfined velocity ofdetonation tests and where possible underwater pond tests. The information obtained from such tests isquite helpful, however it cannot tell us much about the dynamics of the detonation reaction process. The detonation process has been studied for ideal explosives and the reaction zone length have been measured. However, for non-ideal explosives, that type of information is not available. Therefore, the primary aim of this work was to capture the detonation process of a non-ideal explosive using high speed video camera to determine the zone length."

Jan 1, 2017

By Tom Watts

This paper will focus on the design, manufacture and use of pump safety systems on MMUs (Mobile Manufacturing Units – Bulk Trucks) with progressive cavity pumps. The practice of pumping bulk blasting agents is highly regulated and the explosives manufactures have done an excellent job of hazard and operability studies allowing criteria to be established for the safe pumping.

Jan 1, 2009

By Lazar Kricak, Zoran Teodorovis, Dragan Bogunovic

Scattering of delay interval around nominal value is an important issue in blasting practice. The scatter interval, as becomes wider, increases a probability of time delay overlapping adjacent blastholes. An excessive flyrock, ground vibrations, air blast and poor fragmentation are the symptoms for scattering related problems. Utilization of the short delays in the blastholes and longer delays on the surface are recommended solution to overcome mentioned problems. In contrast to global trends manifested through the application of electronic detonators and non-electric shock tube systems, revitalization of inexpensive electric detonators in combination with an accurate initiation system may be an acceptable solution. An extensive work was carried out at the Blasting Center Laboratory at the College of Mining and Geology, University of Belgrade, to develop a precise initiation system. As a result, Sequential Blasting Initiation System – Radio Frequency (SBIS-RF) was developed. It is expected that this system will increase blasting productivity, and reduce negative environmental impacts and total blasting costs.

Jan 1, 2008

By Ronald Ticona

Generally, the drilling and blasting operation are managed independently to the processing plant outcomes. Therefore, the technical segmentation to determinate the ore drill and blast designs do not include processing plant rock properties such as Bond Work Index, Axb, Drop Weight Index or other. This work describes the case study of a copper mine in Peru, which, together with its strategic partner ORICA, have implemented projects focused on optimizing mine fragmentation. The year 2021, mine operation according to its mine plan would have a significantly increased SAG mill hardness, which would impact directly on copper concentrated production. An integrated strategy from mine to plant has become necessary to maintain the production levels.

Feb 6, 2023

By Ravi Sahu, Kris Jeremiah

This paper aims to study the benefits of using Post Processed Kinematics(PPK) surveying methodology combined with Drone photogrammetry to achieve highly precise positioning (X, Y, Z) of drill holes based on the drill pattern and to highlight innovative workflow of transmitting the drill plan to smart drills for accurate drilling.

Feb 1, 2020

By Jonathan D. Aubertin

The unique nature of rock salt blasting is compared to traditional hard rock practices. Rock salt geomechanical nature is discussed in the context of rock blasting events. A cratering mechanism prevalent in soft rocks is presented and exemplified through a series of single hole blast tests performed in salt deposits.

Feb 1, 2020

By Edward J. Walter

Our modern technology is provided with a unique but flexible power tool in the use of explosives. A by-product of explosives usage is vibration or elastic deformation of the earth which is annoying to the ordinary person and can be damaging to structures. The problem is not new, it is more than fifty years old. Adequate vibration standards have been developed so that blasting programs can be properly planned and safely executed. Changes in our social culture have somewhat changed the emphasis in blasting vibration from damage considerations to the much lower level of citizen annoyance. Vibration codes based on this level will be highly restrictive and prohibitively costly. Cooperation is urged between operators, community officials, agencies at all levels,and consultants to see to the development of sound realistic vibration codes.

Jan 1, 1975

By C. Zuniga, S. Combrinck, C. Peters

Agnico Eagle Gold have partnered with Enaex Australia at their Fosterville gold mine to leverage a combination of drill and blast technologies to optimise underground development mining. The mine is the first site globally to collaboratively develop and trial Enaex SWIFT electronic development detonators, which utilise a novel approach to the user interface, simplifying implementation and enabling the benefits of electronic initiation without the complexity of a conventional system. This has been combined with the use of a Sandvik 422i smart jumbo, and the Enaex underground emulsion charging unit with the capability to tailor the delivery of explosives as required and report on a hole-by-hole basis. The combination of these technologies enables full engineering oversight of the development cycle, in turn enabling optimisation of this process in a historically conservative application. The methodology for leveraging these technologies is to bore a controlled and defined blast pattern through using a smart jumbo, load the blast holes utilising lace loading to deliver a desired quantity of ammonium nitrate emulsion per hole, with the ability to reduce chargeweight for perimeter control, and utilising Enaex SWIFT electronic detonators with flexible template type pre-defined delays to initiate the blast holes. Subsequent to firing and excavation the performance of the blast in fragmentation, advance efficiency, and overbreak and underbreak is measured and reviewed. This is then used to optimise the development cycle and apply to other parts of the mine.

Feb 6, 2023

By Tristan Worsey

This work was performed during the summer of 2008 during the junior year of a BS in Mining Engineering. It was observed that the mine was having a problem with back break during the blasting of development drifts. The unwanted back break was causing the mine extra costs in ventilation, ore dilution, ground support, back fill, explosives and man-hours. The blasting practices were observed for four weeks and the problems and their solutions were defined. In this paper the reasons and causes of the problem are explained with the proposed solutions to eliminate back break.

Jan 1, 2010

By Bjoern R. Petterson, Lars Haakon Siem

The world's longest highway-tunnel -- the Aurland Tunnel in western Norway -- is scheduled to be opened in the year 2000. A project to build a main highway between Oslo and Bergen with no ferry connections was approved by the Norwegian Parliament in January 1995. Construction of the five-year blasting project was started by the Norwegian Highway Authority in mid-March 1995, with an expected completion date of November-December 1999.

Jan 1, 1996

By Jose A. Sanchidrián, Ricardo Castedo, Pablo Segarra, Juan Navarro

A study conducted at a mine site that used traditional field surveying and physical hole spot markings bench marked their combined drill and blast performance. The analysis of the operational expenditure (OPEX) improvement determined there were many measurable cost improvements. A primary factor that most operations have to deal with is over drilling of holes. This alone impacts the cost due to nonproductive labor allocations, excessive explosive costs, increased drill tool costs, increased drilling costs and has an impact on the downstream operation cost such as digging the shot material. Other related investigations also show a downstream impact of poor fragmentation on digging payload tonnes, cycle times, haulage payload tonnes, time to load a truck and the number of passes to load the tuck. The intent of this presentation is to draw attention to aspects of mining we understand but may be missing the big picture effects, such as the ability to reduce the operational expenditures consistently to impact the bottom line. The target audience is across the board from owner operators, drill and blast contractors to blasting contractors. Everyone can benefit from these improvements.

Jan 1, 2019

By W. L. Saunders

RBH Note: In the early days of drill & blast tunneling the jobs utilized large crews of drillers and muckers. Advance per round was limited (typically around four feet) but two rounds per 8-hour shift were expected, around the clock. The scene after a shot must have been chaos, with the muckers expected to quickly make space for the drill setup. Makes one wonder how much time was allowed for the smoke and fumes to clear. Note the headgear of the tunnelers.

Jan 1, 2011

By G. Walsh, L. Wolkovitch, A. Savage, V. Romero, T. Zimmerly, G. Imahara, J. Hyneman, K. Byron, D Tapster, S. Belleci, J. Metzger, M. Stanley

Testing was conducted at the Energetic Materials Research and Testing Center for the MythBusters on three separate occasions. This testing included (1) an experiment designed to create diamond from graphite using the shock and pressure of a detonation, (2) the flattening of a car using a steel plate driven by a rocket sled, and (3) the bifurcation of a car also using a rocket sled. All tests were successful; diamond was produced following the detonation of ANFO, and extracted from a graphite / cobalt matrix. A plate was accelerated to 646 mph (1040 km/hr) using a two-stage sled system loaded with 5” (12.7 cm) high velocity aircraft rockets (HVAR) into a car, which was subsequently demolished. Finally, a steel wedge was pushed to 541 mph (871 km/hr) by a one stage sled using HVAR rockets, and was able to cleanly cut a target car in half.

Jan 1, 2010

By Douglas R. Simms

O & G Industries, Inc. owns and operates a number of rock quarries within the State of Connecticut. These rock quarries are surrounded by residences and commercial neighbors who have concerns related to blasting. In addition, local commissions which issue the mining permits to O & G are required to hold public hearings, prior to issuing the annual permits each year.

Jan 1, 1994

By Robert B. Hopler

Hercules Incorporated has designed, developed, and begun introducing a new non-electric delay blasting cap system which is radically different from anything presently available. This system, called Hercudet™, utilizes no wires or detonating cord. Instead, each cap has two plastic tubes attached to it. These tubes contain no coating or other materials other than dry nitrogen to extend storage life. In use, after connecting the tubes together with external sleeve connectors, the circuit is checked with a specially designed tester. When the blast area is cleared, the circuit is filled with a gas consisting of an automatically proportioned mixture of fuel and oxidizer gases. When the circuit is fully charged the gas is initiated by special means within the Hercudet™ blaster. The reaction that then travels throughout the circuit has no distruptive effect on the tubing, and virtually no noise is produced.

Jan 1, 1975

By Cristian Castro, Patricio Gomez, Jason Furtney, Augusto Lucarelli

Understanding the effect of blast-induced damage on wall stability is critical to safe and economical operation of a large open pit mine. In this paper, a numerical modeling methodology is used to investigate damage to rock at distances of greater than 10 m (30 ft) from a blast. Two applications of the model are demonstrated. First, the method is applied at a zinc mine to investigate the effects of pit blasting on underground stopes. The model predictions are compared with the scaled distance formula. Next, the model is used to investigate a common problem in which unfavorable jointing creates a rock wedge on the bench above a blast. The numerical predictions of wedge stability are compared to the wedge energy model described by Wong & Pang (1992).

By Cristian Castro, Patricio Gomez, Jason Furtney, Augusto Lucarelli

Understanding the effect of blast-induced damage on wall stability is critical to safe and economical operation of a large open pit mine. In this paper, a numerical modeling methodology is used to investigate damage to rock at distances of greater than 10 m (30 ft) from a blast. Two applications of the model are demonstrated. First, the method is applied at a zinc mine to investigate the effects of pit blasting on underground stopes. The model predictions are compared with the scaled distance formula. Next, the model is used to investigate a common problem in which unfavorable jointing creates a rock wedge on the bench above a blast. The numerical predictions of wedge stability are compared to the wedge energy model described by Wong & Pang (1992).

Feb 1, 2020

By S. M. Geerts, M. T. Wild

In this paper the performance effects of various shaped charge liner designs will be discussed. Several different charges will be tested and the liner design will be reviewed based on the performance in testing. The first type of shaped charge to be tested is a conical charge with dual confinement. For the purpose of this paper, dual confinement is a shaped charge with two liners but containing one explosive charge. Several charges with different dual confinement designs will be tested. Variations in configuration include charges with similar angle and similar diameter. The second type is a double conical shaped charge configuration. A double shaped charge will be considered to be two complete charges formed into a single cone. The goal of the project is to determine if any of the designs increase the efficiency and/or effectiveness of the shaped charge in comparison to the standard conical shaped charge. A standard conical charge will be detonated against a witness plate to get a standard depth of penetration or a baseline. All charges will have a seven cone diameter standoff, allowing the data to be compared to the control charge. Computer modeling will be used to predict the results of the testing that will be conducted. The actual results will be compared to the computer simulation for validation.

Jan 1, 2010