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By Douglas Bartley, Jay Elkin

The state of Pennsylvania was at one time one of the leading coal producing states in the east. However, legislation and industry trends over the last 10 years have adversely affected the amount of bituminous coal mined in Pennsylvania and the whole eastern United States. The application for and approval of a new mining permit is a very costly and arduous task. When a new mining operation is established it is crucial that nothing within the operator’s control causes the operation to stop producing. This paper discusses the action taken by a small mine in Pennsylvania when their blast induced vibrations rose to levels that typically would have resulted in a total mine shut down by the regulatory body governing such operations.

Jan 1, 2003

By Sri C. Sawmliana, P. Pall Roy

Damage to underground roof and pillars in blasting gallery (BG) panels has been an increasingly important area of study in recent years due to the invention of new explosives and cord systems which has led to the modification and alteration of the design aspects developed by Charbonnage de France (CdF). According to extensive mine experiments conducted by Indian and foreign experts, it has been established that the induced peak particle velocity (PPV) is predominantly related to the emanated seismic energy of a source and the distance from the source. With that concept in mind, nearly 160 experimental blasts were carried out in four BG panels in India under varying geomining conditions. Based on the results obtained thus far, the authors have established predictor equations correlating explosive energy (in Joules) and distance from the shot to that of induced peak particle velocity received at the sensor point. Good correlation was obtained between the actual and the predicted values. It is realized that this equation may be used as an efficient tool to determine the size limit of blasts in BG panels so that the induced particle velocity does not create damage in underground workings as per the established Blast Damage Index (BDI) and other available safety norms.

Jan 1, 2004

By Gregory B. Poole

As part of a $3.5 billion program to improve the antiquated waste water system in the city of Atlanta, the Nancy Creek Tunnel is being constructed across the northwest portion of the city. This tunnel is over eight miles long and is being constructed using Tunnel Boring Machines (TBM) for the majority of the tunnel and conventional drilling and blasting for three shafts, starter and tail tunnels and four connecting tunnels, totaling 2400 feet in length. An extensive public relations program was developed for this project. A group effort by the owner, engineer and contractor produced a public relations program that both informed and educated the public of the anticipated perceptions and effects of the blasting and TBM activities.

Jan 1, 2005

By Rolf Schillinger

Blasting activities on the surface or underground necessarily involve the most sensitive aspect of environment remediation, human response or annoyance. Such effects are unavoidably characteristic of those activities. For this reason, blasting activities are governed by law and official regulations under surveillance of authorities, where companies and explosives engineers have to proceed within proper limits. Subject of the paper is a practical way of handling some necessary vibration standards being focused on blasting activities. The paper is based on the German Standard DIN 4150, Part 1 - 3, “Vibration in buildings”, Part 1: “Prediction of vibration parameters”, June 2001, Part 2: “Effects on persons in buildings”, June 1999 and Part 3: “Effects on structures”, February 1999.

Jan 1, 2006

By Agne Rustan

The 9th International Symposium on Rock Fragmentation by Blasting was held in the Granada Conference Centre, Granada, Spain from the 14th - 17th September 2009. The Symposium was preceded by a 1 ½ day Workshop on “Vibrations from Blasting” organized by the initiator Dr. Alex Spathis and his colleague M. J. Noy, both employed at Orica Mining, Australia. Prof. Josè Sanchidrian at the “Universidad Politécnic de Madrid” in Madrid, Spain was the main organizer for both the Workshop and the Symposium. A record number of participants came (292) from a record number of countries (41). There were a total of 14 papers in the Vibrations from Blasting Seminar and 96 papers and 2 Keynote Addresses in the Fragblast 9 Symposium itself. The aim with this paper is to present some results from Fragblast 9 which are of interest for a large target group. One very important result from the Fragblast 9 meeting was that it was decided there that Fragblast 10 will be held in November 2012 New Delhi India.

Jan 1, 2009

By Steven Putt

Seismic While Drilling (SWD) is a newly developed technology in the mining industry. Improving upon Measurement While Drilling (MWD) systems, SWD measures mechanical properties of the rock at incremental depths down a blast hole at a much higher resolution. SWD is also immune to common failures and inconsistencies of MWD such as operator and drill specific variation. Seismic While Drilling records the velocity and elastic modulus of the rock with centimeter accuracy in real-time. These properties measured while drilling blastholes are then used as a proxy for density which can be used for: • High resolution geologic modeling • 3D ore control • Drill and blast optimization • Drill to mill tracking One of the distinct challenges with SWD systems is the sheer volume of information acquired. With thousands of measurements per blasthole, the data can be overwhelming for even an experienced engineer. To overcome this complex challenge, the latest cloud computing and analytics models have been simplifying and organizing the data. These newer technologies can amplify an engineer’s capability by delivering actionable insights into their drilling and blasting workflows. The paper presents new results from Datacloud during recent Seismic While Drilling trials in iron ore, metallurgical coal, and hard rock mines around the world. The measurements are compared with wireline geophysical logs, core data, drill cuttings, and conventional measurement while drilling (MWD) systems to validate the technology and show how the data can be used.

By Patrice Favreau, R. F. Ph. D. Professor Emeritus Favreau

After Nobel invented dynamite, blasts were carried out by trial and error, without the use of equations based on the fundamental principles of Chemistry and Physics, although everyone accepted that shock waves were involved; but no equations were available to calculate their intensity. Around 1950 however, M.A. Cook proposed a procedure to calculate the thermochemistry of an explosive, and thus evaluate theenergy released during the explosion of a fully confined explosive. Some blasters then began to use theEnergy Factor; the latter, however, does not subdivide the energy into its three kinds of activities necessaryfor a successful blast, as demonstrated in 1968 by reference 2, namely i) the shock wave which weakensthe rock; ii) the stress field SS which fully fragments the rock; and iii) the release of the stress SS whichcauses the fully fragmented rock to burst out with the velocity necessary to move the rock into the muckpile. The article explains that the way to achieve a successful blast is by insuring that the explosive energy divides properly into the weakening action of the shock wave which is necessary to prevent large collar blocks and toe, and into adequate stress field intensity SS which is necessary to obtain good fragmentation size distribution at the crusher, as well as adequate burst out rock movement to achieve easy mucking.

By Robert Hopler

That some time in the year 1872 there was organized an association composed of practically all of the manufacturers of gunpowder and other high explosives in the United States, the members of which said association were as follows: E. I. du Pont de Nemours & Co., The Hazard Powder Company, Laflin & Rand Powder Company, Oriental Powder Mills, American Powder Company, The Miami Powder Company, and Austin Powder Company of Cleveland, all of which or their successors are defendants herein; that the object and purpose of said association was the elimination of all competition between the members thereof in the shipment and sale of gunpowder and other high explosives among the various States and Territories of the United States; that the only manufacturers of gunpowder and other high explosives which did not join such association at the time of its organization were the California Powder Works, The Sycamore Manufacturing Company, and The Lake Superior Powder Company, but your petitioner alleges that each of said three last named companies

Jan 1, 2008

By Joshua A. Bennett

"Lawsuits where owners allege their property has been damaged by nearby blasting routinely costblasting companies, explosives engineers, and others in the field both time and money. When ownersfeel the vibration of a blast, they immediately begin to look for damage and usually find cracking thatwas, in fact, present prior to the blasting occurring. When those owners begin to talk to their neighbors and legal counsel, blasting entities suddenly have multiple lawsuits being filed as a result of the same blast."

Jan 1, 2016

By Dale Preece, Steven Sobolik, Richard Jensen

Recent events demonstrate that civil and government facilities and structures face an ever-increasing need to be designed for protection against malevolent explosions. Modification of existing public structures and especially design of new ones increasingly includes provisions for explosive protection. ISEE members endorse and promote responsible application of explosives to benefit mankind and deplore any other use. However, our knowledge of explosive behavior and our ability to predict the results of explosive events puts us in a unique position to give guidance to designers of civil and public structures. Recent advances in computational methods have resulted in new computer codes with ALE (arbitrary lagrangian eulerian) simulation capabilities. Historically, lagrangian computational methods have been used for modeling solids because the mesh or discretization moves with the material. Rock breakage resulting from explosively induced shock-waves has been successfully modeled with lagrangian codes. Explosive detonation has traditionally been modeled with eulerian techniques. Eulerian methods have been used to model gases and fluids, tracking the material as it moves through the computational grid. ALE computational technology couples the two methods together in a manner never before possible. An ALE simulation can accurately treat the explosive detonation, interaction of explosive gases with air, and the impact of explosive event on nearby solid structures. ALEGRA (Budge et al. 1997 a & b) is an ALE code developed at Sandia National Laboratories. ALEGRA simulations accurately predict the explosively induced impulse on the structure to be protected. It has been applied to the analysis and design of blastwalls to protect structures and people from explosive events. The impulse calculated can be used by structural engineers to design a blastwall. ALEGRA has also been applied to predict the effect of a blastwall on explosion overpressure some distance behind the blastwall to assess the effect on people present during the event.

Jan 1, 2000

"Rock falls involving a relatively small amount of material are a leading cause ofinjuries in underground mines in the United States. A contributing factor is unwantedblast damage and over-break. A goal of the United States National Institute forOccupational Safety and Health is to reduce the number of ground fall-related accidents by improving drift driving practices through the introduction of perimeter control blast designs. This paper presents a blast design technique based on a hydrodynamic method. Using commonly available explosive and geometry data, the theoretical particle velocity is calculated as a function of distance away from a cylindrical charge. A calibration factor is introduced to account for actual conditions by comparing the predicted values to a set of field data. The calibrated curve can then be applied for design. The paper introduces modifications to account for different explosives from those used in a calibration test. The application of the approach is demonstrated with respect to a data set from a large-scale concrete block test."

Jan 1, 2009

By Michael Allen, Paul Worsey

In underground blasting, the pull of the initial cut is the limiting factor for the success of the rest of the round. By improving the pull of the first cut, a critical step is made towards improving the entire round. This project attempted to optimize a burn cut’s effective pull by varying the depths of the relief holes in the burn. The effect of varying the depths of the relief holes was investigated, including depths longer than that of the cut’s charged holes. The overall objective was to consistently achieve greater pull than in a standard burn, using an identical amount of explosives. Increased pull results in savings of both time and cost in underground heading advance.

Jan 1, 2015

By Rowan A' Murry Karstel

One way to ensure dragline productivity is by Increasing the size of the dragline bucket. In August 1994, Optimum Colliery in conjunction with Van Reenen Steel, Northwest Applied Technology, SSAB of Sweden and Barlows Equipment launched the new lightweight dragline buckets. Optimum built the first prototype bucket that was used for the deslgn for future buckets. After knowledge had been gained from measuring the input force of the bucket Northwest Technologies designed the new bucket with finite element analysis. Together with the knowledge of quenched and tempered steel from SSAB of Sweden and Barlow Equipment, the new Wrightech bucket was born.

Jan 1, 1998

By Choon Sunwoo, Chang-Ha Ryu

There are various methods available for the recovery of dimensional stone in open pit quarries. Explosive blasting has more advantages in the economic point of view over the other methods but was not widely used in Korea because owner was concerned about much economic loss when it failed. Several years of efforts have been made in order to develop more effective cutting methods and to spread to the quarries for strengthening the competitiveness in the market. Rock cutting by jet flame and black powder was generally used in the early stage. Black powder was applied to cut the last horizontal plane after forming other vertical planes using the jet flame. Jet flame operation, however, is time consuming and produces excessive noise, and as the result, brings adverse effects on the operator as well as the complaints from the residence adjacent to the quarry. Some mechanical methods such as the slot drill, diamond wire saw or in-situ scale of diamond saw cutting were introduced. Most effective cutting methods using the explosive blasting were developed and applied successfully. Black powder was replaced with the detonating cord. A new air decking technique where plug was not used was developed. This paper reviews the technology for dimensional stone cutting and case study in Korea.

Jan 1, 2003

By Alan: Moore Richards

Effective control of airblast requires that significant factors be identified and satisfied by blast design and careful implementation. Significant factors include charge mass, distance, face height and orientation, burden, spacing, and initiation sequence, stemming height and type, topographical shielding, and meteorological conditions. This paper utilizes case histories of blasting in Australian open pit mines to demonstrate techniques that have been used to control airblast to applicable limits.

Jan 1, 2006

By Neal Lee, Braden T. Lusk, Jhon Silva-Castro, Patrick J. Jenks

"Timing and charge sequence are very important for optimized blast design. Traditional nonelectricinitiation systems have moved the industry toward a system of delays consisting of hole-to-hole androw-to-row timing sequences that mimic the application of nonelectric surface delays or dual delayinitiator systems that have been prevalent in the blasting industry for many years. The increasedutilization of electronic detonators allows for the use of Regular Rhythmic Timing (RRT) utilizing onlyone delay between charges and a selected charge firing sequence. The hole to hole and row to row (HHRR) timing method has been utilized for blasting optimization and allows for simplistic changes to the tie in phase of the blasting sequence. When using this traditional timing methodology, for some specific cases related to the number holes and rows, crowding occurs in the delay between charges with subsequent increase in the peak particle velocity (PPV) produced by the blast. This is in contrast to RRT where the timing between the delays remains constant."

Jan 1, 2016

By Rapheal Trousselle

For over 5 years, Davey Bickford has been developing and testing an electronic detonator blasting system. These new-technology detonators provide more accurate timing than conventional systems that rely on the combustion speed of a pyrotechnic composition.

Jan 1, 1997

By Charlie Brumbaugh

Antarctica with its diverse conditions such as severe cold, high winds, rock and ice structure and limited explosives available posed many obstacles. This paper will give an overall view of the methods used to overcome these obstacles on a daily basis on the highest, driest, coldest continent on earth.

Jan 1, 2000

By Jim Mikelait

Overview ?? Why do we need security? ?? Needs assessment ?? Elements to any security system ?? Protect, Detect, Alert, esponse ?? Electronic Security System Criteria ?? Advantages and Limitations of Various Security Options ?? Internal measures to protect against potentially harmful employees ?? How can technology improve my business?

Jan 1, 2006

By M Scoble

This paper will report on the application of data collected through the performance monitoring of large diameter surface rotary blasthole drii and electric mining shovels, in an integrated approach to blast optimizatiion.

Jan 1, 1992