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By Yang Jun, Qu Mei, Zheng Yao-wu, Chi Li-yuan

Due to the necessity of the prediction of blasting seismic effect around strip mine bench blasting area, the paper provides a method to predict the blasting seismic effect by employing the superposition of seed waveform at different monitoring points. The method assumes that blasting vibration waveform per hole is similar to seed waveform at monitoring point. Therefore seismic wave consists of the superposition of the waves from all of blast holes. Firstly, via sensors multiple seed waveforms can be achieved at different distances from signature hole. Then, by using the given dose and the distance, the vibration waveform of a certain blast hole can be calculated by the corresponding seed waveforms. Finally, the initiation delay time interval per hole is added to the propagation time to the predicting point. The predictive waveform at the whole blasting area can be obtained by superimposing all of the single waveforms. Considering the vibration waveform of a single blast hole changes greatly with the distance, under different distances condition the seed wave employed to superimpose is achieved from the similar distance. The experiments demonstrate that based on the method the predictive vibration waveform and spectrum are basically consistent with monitoring results around near-field blast. Compared with single seed wave method, the superposition method of multiple seed wave is more reliable to predict the duration of blasting vibration, the peak particle velocity, dominant frequency and frequency distribution.

Jan 1, 2015

By Cathy Aimone-Martin, Robert Brentar, Brent Meins, James Lauer

Vibration measurements of multi-story structures in an urban environment began 3 years ago in New York City during close-in blasting to adopt correct measurement procedures and recommend revised ground vibration limits that best characterize cracking potential in mid- to high-rise structures. Two broad categories of structures included non-engineered 4- to 6-story multi-family unreinforced brick masonry buildings, built from the late 1800s to around 1930, and post-WWII, high-rise structures of reinforced concrete and steel rising 12 to 40 stories. In-ground vibration limits similar to those recommended by the U.S. Bureau of Mines safe criteria, developed for 1- and 2-story residential structures, are imposed by the New York City Fire Code. However, these limits are often lowered by project engineers or New York Department of Buildings when blasting is planned near buildings designated Landmark or historic and classified as fragile or vibration-sensitive. Seismograph measurements to determine compliance with in-ground velocity limits currently employ geophones mounted to basement walls and on concrete slabs overlying rock. These measurements cannot be correlated with upper structure cracking potential and are often exceeded, resulting in excessive and costly downtime to allow post-blast damage investigations.

Jan 1, 2014

By Zach Ellis, Dusty Fisher

The Office of Surface Mining, Reclamation, and Enforcement (OSM) cited a large surface coal mine for a series of flyrock incidents that occurred when blasting close to the mining lease perimeter. The OSM placed the company on a pattern of violation status. It was determined through analysis of blasting practices that flyrock could be controlled at the mine by drilling a smaller diameter hole and stemming with crushed rock when blasting within 1,000’ (304 m) of the lease line. The procedure to install and remove the small diameter drill steel was cumbersome and dangerous because it was a manual transition. The drill carousel could only hold one diameter at the time the project was initiated. The process was very time consuming, involving a mechanic to transport the steel to the drill and spend up to 1.5 hours of downtime switching the steel. In addition, the hydraulically operated break-out wrench and break-out fork on the SKS Infinity Redrill® is only designed to work with one diameter, so these tools could not be used to disconnect subs and steels on the string. At the time, the mine’s breakdown was between 30-40% small diameter (6 ¾” (171 mm)) versus large diameter drilling (10 5/8” (270 mm)). The drill and blast group was challenged with the task to implement a 6s (Six Sigma) project that would reduce the amount of time spent on steel change-outs on the rotary drills while improving the safety of the task. A solution was proposed to carry the small diameter drill pipe, lower small diameter sub, and small diameter bit on board the drill at all times. The goal of the project was to carry the steel in the carousel after modification so that the driller could change the diameter himself on board the drill in less than 45 minutes without any assistance from a mechanic. The drill had to be modified so that the hydraulic operated break out wrench and deck fork could be utilized on both diameters. The drill accessory supplier and the mine worked together to design and implement design changes and new equipment onto two rotary drills, and new standard operating procedures (SOPs) were created for the new process. The project has been in the sustaining phase for approximately three months now and all steel diameter changes are completed by the operator under the allowable time limit.

Jan 1, 2015

I was lucky to land a job in the powder business. I was looking for some way to support my wife and first child to be when I saw an ad in the Hercules magazine, “Explosives Engineer” for technical representatives. I answered the ad in hopes that a geologist might find something else to do besides sit oil wells or “doodlebug” for oil. Both of these occupations I had tried and while the money was good the life was a bit erratic. The Army also wasn’t made for a guy who asked too many questions although my two plus years in uniform were interesting and in a few cases fun.

Jan 1, 2004

By SMF Hossaini

With the aim of a clearer understanding of the applicability of existing empirical equations for blast induced ground vibration, an investigation has been conducted on three mostly applied forms of such equations. The effect of explosive type on the applicability of these equations has been assessed by analysing 44 sets of data produced by using two types of explosives, namely ANFO and slurry explosive, in an open pit coal mine. The analysis of the data has revealed that the type of explosive affects the applicability of the criteria of the three equations. All three criteria have better correlation with the data of shots in which ANFO was used than the shots with slurry explosive. However, the applicability of one of the criteria is reduced, by far, only by replacing ANFO with slurry explosive for the same ground conditions. It was also found that one of the parameters of these criteria (i.e. “k”) is significantly sensitive to the type of explosive in all the three equations. The degree of influence to the values of “k” obtained by the variation of explosive from ANFO to slurry explosive in the three equations is 76.3%, 811% and 39%. This implies that “k” is not only dependant on ground conditions, as stated in most previous publications, but is also strongly a function of the type of explosive.

Jan 1, 2004

By D Vidyarthi

Blasting is the most important activity in the mining industry, the world over. It is a well known fact that only part of the explosive energy gets utilized in causing the actual rock fragmentation. The rest of it gets converted into blast-induced ground vibrations and noise. Though blast vibrations cannot be totally eliminated, it is possible to minimize them by optimization of blast parameters. This paper highlights various in-house efforts put forth by the author towards site specific blast optimization and the monitoring of blast vibrations. It also deals with the prediction curves developed by regular regression analysis for the prediction of ‘blast vibrations’, ‘peak particle velocity’, ‘safe charge’ for various blasts.

Jan 1, 2007

By Chris Uys, Johan Labuschagne

Sishen Iron Ore Mine, located in the Northern Cape, is an open cast mine excavating approximately 100 million tons rock to produce 25 million tons of high grade haematite ore per annum. The size of the pit is approximately 12 km ‘1.5 km ‘150 metres. The final depth is planned to be around 350 metres. It is hard rock mining operation employing the conventional truck and shovel method. Mining benches are twelve and a half metres in height and are divided into blasting blocks, each consisting of approximately 300 000 tons of material.

Jan 1, 1997

By Earl C. Hutchison, Wade C. Hutchison

T 0 effectively evaluate property damage that is claimed to have been caused by blasting activities and in order to lay the proper foundation to build the best legal defense, identification of the actual causation for the damages are necessary. For the past twenty years, engineering personnel from VCE, Inc. (previously Vibration Control Engineering, Inc.) have been evaluating claimed blasting damages with pre- and postblast inspections, with analysis of seismic levels, blasting amounts at given distances, and with other engineering considerations. In addition to these evaluations, they have also documented other causes for damages which are of the types that are often claimed as blasting damage.

Jan 1, 1995

By Ali Kahriman, Abdulkadir Karadogan, Deniz Adiquzel, Umit Ozer, Suat Bicer, Mehmet Aksoy

This paper presents the analysis and measurements of blast-induced ground vibrations during the construction of Istanbul Kagithane – Piyalepasa – Dolapdere – Dolmabahçe highway tunnels. These tunnels known as T1 and T2 are being constructed by a joint venture group. Within the scope of the study, the particle velocities and frequencies associated with 126 shots during the advancement of the tunnels were monitored and analyzed by vibration monitors at the test site. During the statistical analysis, three different predictor equations widely used in the literature were used to predict peak particle velocity (PPV) and the results and comparison of the predictor equations are presented in this paper. Finally, the particle velocities and frequency values of all blast events were evaluated according to USBM and German DIN 4150 Norms in order to determine the damage risks of the neighboring buildings and structures.

Jan 1, 2008

By Bruce Vandenberg, Andy Battfay, Don Lake, Steve Conway, Jeff Yorsz

"High-speed motion pictures are an invaluable resource for blasting analysis. Whether processed by the human eye or a computer, this imagery can provide important insight into a blast and its effects.While certainly popular, traditional high-speed film cameras hamper this process. Instant feedback is not available since film requires developing and, relevant in the case of automated analysis, film isnot immediately compatible with a computer. With these facts in mind, a new high-speed video camera system, the SVCSOO, has been developed. The SVC500 combines the capabilities of a high-speed film camera, the convenience of a solid-state digital video camcorder, and the computing power of a ‘486 PC to provide a complete, standalone platform for high-speed image acquisition and analysis. This paper will describe the design, features, and use of the SVCSOO andcompare these with the analogous aspects of film cameras."

Jan 1, 1994

By Randy Wheeler

The importance of having full wave form information for recorded blast events cannot be overstated. Knowing the peak particle velocity and the frequency at the peak are the tip of the iceberg. This presentation will focus primarily on using the FFT (fast Fourier transform) for detailed frequency analysis. Employing linear superposition to evaluate timing effects on amplitude and frequency will be discussed.

Jan 1, 2005

By Jeffrey L. Dean

Now in its twenty-fifth year, the ISEE has grown to more than 4000 members representing 75 countries. The Society and its 35 chapters in the US, Canada and Australia work to educate the public about our industry, provide forums for the exchange of explosives technology, serve as a repository of explosives information, offer expert help to governments, develop standardized methods and terminology, and promote research and education by, creating and conducting certificate and trainktg programs and encouraging the teaching of the safe and controlled use of commercial explosives.

Jan 1, 1998

By Kyle Wagner, William Joa, Colter Angell, Catherine Johnson, Marty Langenderfer, David Doucet

The goal of any business is to seek the maximum profitability for the organization through optimization the use of resources, processes and the application of new technologies. An analysis of various case studies demonstrate that blasting can have positive impacts on the crushing and milling processes resulting in increased profitability for the mining industry (Grundstrom, Kanchibotla, Jankovich & Thornton, 2001). This paper describes the case study of two copper mines in Peru producing Cu-Mo and Cu-Au concentrates, which together with their strategic partner, have implemented a project focused on the improvement of rock fragmentation. The project was based on techniques of pattern size reduction, the use of high energy explosives and the technology of electronic initiation. Combined, these techniques were shown to have significantly impacted the efficiency of downstream processes.

Jan 1, 2019

By Frank Hirthammer

Productivity, customer relations, and effectiveness of work depend to an ever-increasing extent on a functioning logistics system tailored to the needs of the user. Of course, it is not possible to cover and explain all aspects of the logistical requirements of even a small part of an industry, in a single article. The article speaks specifically about the particularities and differences in the logistical requirements in the explosives sector. Starting with questions of safety, handling and quality up to the legal basis, there are special requirements regarding the logistics in the explosives sector. The results of innovative logistics solutions are presented using three examples from daily work practice.

Jan 1, 2019

By Randall M. Wheeler

Many of us have used a seismograph to measure peak particle velocity and frequency. But do we really understand why? Also, why do we measure particle velocity instead of displacement and/or acceleration? What is the vector sum? How do these items relate? Where does frequency fit in? This workshop will attempt to answer these and other questions. Some of the answers may surprise you, others may not.

Jan 1, 1997

By Bruce Vandenberg

Two tests were set up as part of the course given by Blasting Analysis International. Both tests were performed using the prototype Velocity of Detonation Recorder (VODR). The prototype has several limitations, which have been rectified for the production units.

Jan 1, 1990

By U. Gorkhan Akkaya, N. Enver

Geographic information system (GIS) is one of the most accurate and useful tools to help decision – making for decision-makers. As to expert systems, it provides solutions to the problems faced by mimicking reasoning of the human experts. Blasting operations in mining include high risks for the vicinity of the operations. GIS having required mechanisms to take right decisions for the people who have to make right and precise decisions, while it is utilized as a integrated system with expert reasoning, is thought to be considered important tool that provides to take decisions with ease, and also to reduce the risks in the blasting operations. It is possible to find out both of the economic and optimum solutions to solve the various encountered problems in the mining activities such as blasting operations, only when GIS integrated expert systems is used. Managing the spatial data unified with expert reasoning is the one of the greatest advantages of the system. In the scope of the study, various scientific studies were investigated. The benefits of the system were figured out and the phases of a unified system were proposed in the blasting operations.

Jan 1, 2013

By MacDonald B. Johnson, Douglass P. Bacon

"W ith the advance of science, rise of public interest in environmental matters, and continuing erosion of air quality, federal and state regulators are demanding an increasing complex array of data concerning emissions produced by burning and detonating energetic materials. The U.S. Department of Defense, one of the world’s largest consumers of energetic materials, now must characterize combustion products resulting from open burning/open detonation disposal operations. The catch-all phrase “below detection limits” no longer satisfies the regulators who nowwant testing to delve into the ppt level for volatile organic compounds and ppt level for semivolatile organic compounds."

Jan 1, 1995

By W. J. Birch, L. Bermingham

Air overpressure is becoming an increasingly problematic issue within the quarrying industry. With blasting operations moving ever closer to residential properties, the number of complaints about air overpressure is beginning to increase. It is therefore important for operators not only to have a greater understanding of the blasting parameters that give rise to air overpressure but also the factors which have an effect on air overpressure levels as it attenuates with increasing distance from the location of the blast.

Jan 1, 2013

By Brent Blanchard

Dallas/Fort Worth Airport recently took a major step in its fiveyear expansion project with the explosive demolition of the Hyatt Regency Hotel West. Built in 1965, the Hyatt Regency held the distinction of hosting five U.S. Presidents over the years and was reportedly one of the first hotels in the world to be built within an airport’s boundaries.

Jan 1, 2003