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By Roger Scarr, Richard A. Walker

Interactive video is the combination of computer and laser disc -technologies that allows for the storing of 54,000 single images or 30 minutes of video with the ability to access any segment or single image within a half a second. This capability combined with the use of a graphics overlay on the video and accessed through a keyboard or touchscreen creates a very powerful and versatile marketing or training tool.

Jan 1, 1990

By Wang Zhong Qian, Liu Hui

The paper proposed a fractal and damage model for rock-breaking by blasting, which assumed that the process of rock-breaking results from intrincent fractal development and the accumulation of damage. Remarkably, the process is of fracture character. Based on the model, a computer program is compiled to calculate the 3-dimension damage distribution in blasting crater. Trial results agree well with the predicted results, showing the model set up in the paper is sound.

Jan 1, 1997

By Dong-Hyun Kim Kim, Tai-Ro Lee, Young-Hwa Seo

Overbreak occurred inevitably in a tunnel excavation, is the main factor for increasing cost and period in tunnel projects. Furthermore the damage to the remaining rock mass related to the overbreak can give rise to a serious safety problem in tunnels. As a rule of thumb, causes for the overbreak are inaccuracy in drilling, the wrong design of blasting and selection of explosives, and heterogeneity in rock mass. Specially, the geological features of the rock mass around the periphery of an excavation are very important factors, so a lot of research has been conducted to describe this phenomena. But the geological rockmass classification for the overbreak and the method for decreasing the overbreak have not been fully established. Besides, the technical improvement of the charge method is needed as explosives for the smooth blasting have not functioned efficiently. In this study, the working face around periphery of an excavation has been continuously sectionalized to 5~ 6 parts, and the new Blastability Index for the overbreak based on 6 factors of RMD(Rock Mass Description), UCS(Uniaxial Compressive Strength) JPS(Joint Plane Spacing), JPO(Joint Plane Orientation), JPA(Joint Plane Aperture) and FM(Filling Material) is proposed to classify sections of the working face. On the basis of this classification, the distance between contour holes and the charging density are determined to minimize the overbreak. For controlling the charging density and improving the function of explosives, the New Deck Charge(N.D.C) method utilizing the deck charge effect and detonation transmission in hole has been developed.

Jan 1, 2003

By Larry Schneider

In the construction field and to a lesser degree in mining, flagman are often necessary to move traffic and or pedestrians through work zones. Everyone readily recognizes that they are essential for the safety of the general public and the employees on the job. What is not often considered is the safety of the flagmen themselves. Actually, let’s call these employees “flaggers” recognizing the fact that there are as many women as men doing this job. The first problem we need to overcome is the misperception that flagging is a low skill function that can be done by any untrained employee. The reality is that the flagger works in a very hazardous position with serious responsibility for the safety of his fellow employees and the public at large. And to do this job properly re q u i re s that the flagger receive sufficient training before being sent out to the highway. It is also necessary to convince the flagger of the value and importance of their job in order to motivate them to do a professional job.testing, documentation of both, and accurate re c o rdkeeping are key aspects of HM126F. Of course, training and documentation requirements will vary depending on the type of operation involved, and there may be some differences in the application of requirements depending on your jursdiction. Nonetheless, failure to train and properly document such training can result in heavy fines and/or penalties.

Jan 1, 2004

The objective in control blasting is to reduce overbreak to control the final pit wall slope, shaft, drift, ditch, bench, etc. to the final planned excavation limit.

Jan 1, 1990

By Theirry Bernard

The era of non-electric systems as an initiating system has revolutionised the blasting world by introducing a very safe initiating system that is reliable, with initiation sequence possibilities that are superior to those of purely pyrotechnical or electric systems. Electronic initiation has brought with it accuracy, programming and controls that were lacking in the non-electric systems. However, it has also led to a certain degree of complexity, which works against user-friendliness, sometimes introducing a few constraints that are balancing out the intrinsic performance of electronic detonators. The introduction of a hybrid initiation system, Electronic and Non Electric, offers accuracy, and flexibility that were lacking in non-electric systems, whilst removing the inherent complexity of electronic systems. This paper endeavours to summarise the advantages and disadvantages of non-electric and electronic initiation systems that have been recorded after years of experience on site. The paper will then describe how a hybrid system only keeps the advantages whilst eradicating the disadvantages, via a case study.

Jan 1, 2007

By Alan Minchinton, Ian Kirby, Jim Chan

It has long been known that successful blasting in soft and hard rock can require the use of different explosives. While choosing an explosive of the right energy density is important, the dynamics associated with non-ideal detonation behaviour play an equally major role. Tuning the energy release rate of an explosive to optimise its blast efficiency can be likened to tuning an internal combustion engine to improve its performance.

Jan 1, 2014

By Richard Hosley, James Daley

Every grey haired member of the explosive’s industry has said at least once, “We have to get some younger blood into our industry, I might want to retire someday.” And many a youngster who loves to see explosions has wondered how to get involved in such an exciting, yet intimidating, industry. While there are many answers to these questions, an internship program is a great answer to both

Jan 1, 2014

By J R. "Dick" Daniel

One of the more common tasks in blast management is the adjustment of: shot geometry, explosive energy, and shot timing parameters to achieve changes in blast outcomes and costs. Many of these shot parameters, once a delayed blast is initiated, are modified by the development of new free faces which change the original or static input values to dynamic values. These newly generated dynamic values are easily calculated and find use in fine tuning shot adjustments and in rationalizing blast outcomes in a systematic manner.

Jan 1, 1996

By Lewis L. Oriard

The purpose of this paper is to provide an overview of close-in blasting effects on various types of structures and building materials, as encountered in this writer's professional practice. Structures range from old, deteriorated historical monuments to new, heavily reinforced buildings. Materials range from clay adobe to concrete and steel. Site locations range from tropical to arctic. Blasting ranges from sculpture blasting inside buildings to "coyote" blasting and large surface blasting operations. Space limitations permit a brief discussion of only 25-30 specific cases, but they have been selected to be typical of conditions found on hundreds of similar cases. The writer was asked to present a discussion of representative cases where relatively high vibration intensities were experienced. Virtually all of these cases were free of damage, but the few damage cases provide valuable insight to the mechanisms involved. Observations of such damage and non-damage cases have served as the basis of this writer's criteria for various structures and materials, as well as the technology to conduct blasting operations within those criteria. A sampling of these experiences is gladly shared with the reader.

Jan 1, 1991

By Ann Barron

Even though you think your company’s safety program is the best it can be, equipment, processes, supplies, surroundings and people do not always behave or react as expected. Consequently, needless accidents occur each year at quarries, construction sites, surface mines, and other locations where explosives are used. While blasting accidents account for only a small portion of the total accidents reported, the severity rate for blasting accidents is higher than for any other accident category.

Jan 1, 2007

By Ettore Contestabile, Cameron Thomas

Implosive connectors such as XECONEXTn have been used extensively for joining electrical conductors. This implosive action of explosives has also been used in other forms of high-energy metal working with excellent results. However, the inherent blast energy of these units can cause environmental side effects (especially airblast) which may restrict their use around inhabited areas.

Jan 1, 1994

By A J. Rorke, U Chhika

"A series of tests was carried out on a dry blend of PPAN and LAN prills (LANFO). The objective of thetests was to determine detonation stability and VOD performance compared to ANFO. Heave andfragmentation results in the field were also evaluated visually. A number of factors were behind for.mulating this blend. A lower cost is combined with higher in-hole energies, but at slower reactionrates and lower peak borehole pressures. The resultant effect is improved heave characteristics andlower energy losses caused by inefficient crushing of the rock immediately around the borehole.The test results indicate that IANFO is ideally suited to blasting in softer midburden and overburdenrock types often encountered in coal strip mines."

Jan 1, 1995

By Francisco Sena Leite, Pedro Brito, Gean Frank, PhD Soeiro de Carvalho, Jose, Vinicius Miranda

The consequences of rock blasting with explosives are directly related to the accuracy of drilling and, because they have an effect on fragmentation and ground level, they should be controlled to ensure a problem free production, increase work safety and reduce environment impact. Safety control is one of the most important processes in detonation, since it can compromise the worker security on site and, eventually, neighboring communities. Due to the technology advancements, it is possible to build a hole deviation control device with “of the shelf” parts, and for that reason the authors decided to evaluate the possibility of measuring hole deviation by creating a portable prototype using an electronic sensor capable of measuring the acceleration on objects, that is, to measure the own acceleration of a system, known as "accelerometer" and a micro-controller to handle and treat data. The main idea behind this paper is to validate the power of the Euler method, given the stepping limitations of the sensor and micro controller in order to reproduce of the hole shape. A case study was carried out, comparing the measurements of borehole deviations made by a traditional equipment and the prototype. A mobile application was also created in order to recover and treat and display the data to the user. For validation of the prototype, several holes were measured using the two devices. A residue analysis was used to validate the data obtained. After analyzing and confirming the effectiveness of the new equipment, the normality tests prove a symmetric distribution with null expected residual mean and minimum variance. Consequently, the accuracy of the prototype is evidenced. Thus, the authors aspire to emphasize the potential of using these sensors allied to a traditional numerical method for analysis of hole deviation.

Jan 1, 2019

By Michael Swisdak, John Tatom, James Tancreto

In 2002, testing was proposed to generate needed data to assist in developing improved explosives safety standards within the US Department of Defense. This testing emphasizes two major areas: (1) full-scale donor/acceptor trials examining debris generation and acceptor response and (2) debris perforation testing of representative roof/wall materials. The full-scale donor/acceptor trials are referred to as the SciPan series. The first three tests in the SciPan series have been completed, as has the first phase of the SPIDER program. This paper describes the status and future of these testing programs, reasons for choosing specific tests, potential benefits, and planning for future phases.

Jan 1, 2006

By Scott Rosenthal, Logan Connolly

Butte, Montana holds a prestigious place in the history of mining, deemed “The Richest Hill on Earth,” containing a plethora of underground mines. The Orphan Boy/Orphan Girl underground mines, on the western side of Butte, operated from 1895-1956 producing zinc, lead, silver, and manganese. Today, the Orphan Boy mine is part of Montana Tech’s Underground Mine Education Center (UMEC) and the Orphan Girl mine houses the World Museum of Mining. Underground development in the Orphan Boy mine continues to progress as students from Montana Tech receive hands-on underground training; in addition, the UMEC is a multi-disciplinary research facility. Repeated underground blasting occurs in close proximity to old mine workings (wood supports installed circa 1950 or earlier). Research began to determine the impact of underground blasts on nearby pre-existing structures. Using the ISEE Field Practice Guidelines for Blasting Seismographs, one seismograph monitors the predominately-wooden structures to measure their response during each underground blast and one seismograph positioned on the surface to monitor surface structure response to the blast. This paper presents the findings of the research conducted to date for the project. The paper includes analysis of the research data, and conclusions determined from the research. Recommendations for the future work are included as well.

Jan 1, 2018

By Stephen H. Chung

The blasting performances identified above are considered to be the most practical ones for judging the effectiveness of a design combining explosives / rock / drill pattern. In a total blast design process, productivity relates closely to both fragmentation and heave / displacement of muck. In cast blasting, the more overburden displaced by explosives, the less blasted material there is left to be removed with mechanical equipment such as draglines or trucks. For wall protection and dilution control, estimates of the maximum extent of cracks / damage generated in situ due to blasting will help determine the location for drilling and loading perimeter blastholes.

Jan 1, 1994

By Douglas A. Bartley, Davey Bickford, Raphael Trousselle

The long awaited arrival of a high accuracy detonator to reach the explosives end user will provide new opportunities the blasting community to become better equipped and able to improve upon the current approaches and methodologies used in blast design as they apply to the mitigation of adverse effects from blasting. This paper will detail the approach and findings throughout a several month research project to quantify the high accuracy detonator benefits and to mitigate a long standing vibration problem at a hard rock stone quarry in the state of New York. The tests conducted in this study were designed to provide important information as to the relationship between the use of high accuracy detonators and overall blast performance in terms of ground vibration prediction, control and improved rock fragmentation.

Jan 1, 1998

By P D. Katsabanis, W Roberts

Commercial explosives exhibit non ideal behaviour which is very difficult to model. The fume spectrum produced by commercial explosives apart from its practical significance for underground mining is of great theoretical importance since it reveals information about the chemistry of the detonation process. Emulsions, watergels and dynamites were tested under various degrees of confinement in an one cubic metre closed chamber. Sand, concrete, steel and copper pipes were used to alter confinement. The degree of confinement was found to significantly influence the quantity (litres/kg of explosive) and the relative proportions of toxic and non-toxic fumes (percent of total fume measured). These results lead to further confinement testing using various rock materials. Fume results, and thus detonation performance were found to be dependent on the type of rock material used for confinement. Materials such as dolomite, limestone, and granite were found to result in a relatively high detonation efficiency of the subject explosive as shown by the distribution of detonation fume products. Conversely materials such as sandstone, talc and massive sulphide resulted in fumes suggesting low relative detonation efficiency. Fumes appear to be a sensitive indicator of the completeness of reactions occurring within the expansion zone of the composite emulsion explosive, while the detonation velocity is relatively insensitive to small variations in confinement. Estimates of sonic velocities of the confining rock materials were found to show no correlation with VOD results. However good correlation between fume results and sonic velocity suggests that the performance of an explosive as indicated by the resulting fume spectrum is affected by the degree of confinement.

Jan 1, 1992

By William Hustrulid

Pre-split blasting is a primary technique for creating slopes with a minimum amount of unwanted damage to the remaining rock mass. Rock slopes created in such a way have both safety-related and economic advantages. The applications extend from road cuts to rock quarries to large open pit mines. For example, as deep open pit mines approach the end of their operating lives, slope steepening is one option to be considered. To be able to safely achieve and maintain steepened final slopes, good blast design techniques must be available and applied together with close operational control. Pre-split blasting is an important element in this slope creation process.

Jan 1, 2007