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By Luis Valentim, John E. Wiegand

Highwall or face profiling has long been used to facilitate the design and placement of front row blastholes to ensure optimum burdens. Traditionally, a large number of laser measurement points obtained from the rock face or highwall, were input in profiling software packages. This method can be time consuming and requires access to the rock face with a complete view of the highwall, to be successful. Stereo photography has also been used to generate the rock face surface, but this method also requires access to the highwall (and pit floor in some instances) for measurement of reference targets or points.

Jan 1, 2016

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 Dale S. Preece

The computer program. DMC Qistinct Motion &de), which w&s developed for simulating the rock motion associated with blasting, has been used to study the intluence of row delay timing On rock mOtiOn. The munerical simulations correspond with field observations in that vmy short delays (< 5Oms) and vety long delays(> 3oOms) produce a lower percent-cast thao a medium delay (100 to ZOO ms). The DMC predicted relatio&lp between row delay timing and percent-cast is more complex than expected with a dip in the auve where the optimum timing might be expected. More study is required to gain a full undasranding of this phenomenoo.

Jan 1, 1994

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 Joshua Taylor Drake

This report answers specific questions concerning underwater blasting considerations, and blasting safety. The blasting considerations discussed consist of basic blasting principles, and new variables to be accounted for. Blasting safety will include the safety of personnel and structures. The environmental considerations will also be discussed with mitigation methods. To be most effective, this document requires the reader to be familiar with key fundamentals of explosive engineering. In order for a blasting professional to benefit from this report, the following questions will be asked:

Jan 1, 2015

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 Ali Kahriman, Abdulkadir Karadogan, Umit Ozer, Mehmet Aksoy, Kagan Ozdemir, Adiguzel Deniz

This paper presents the results of ground vibration measurements induced by blasting during the construction of the Istanbul Kadiköy-Kartal metro tunnel which has been driven at a depth of approximately 20-40 m deep under a highly urbanized region of Istanbul city in Turkey. This tunnel is being constructed by a joint venture group. The formation encountered during the construction is classified as hard and strong rock by laboratory and field tests performed by the joint venture group. Within the scope of the study, for the prediction of the peak particle velocity and to determine the slope of the attenuation curves together with the maximum charge per delay for the S4 shaft tunnels and S12 shaft tunnels of this tunnel route, ground vibration components were measured carefully by using four vibration monitors (Instantel Minimate Plus model) during the advancement of the tunnels which required blasting. The particle velocities and frequency values of all blast events are evaluated according to the United States Bureau of Mines (USBM) and German DIN 4150 Norms in order to predict, and compare the influence grades to the neighbouring buildings, and structures. Also, data pairs of scaled distance and peak particle velocity obtained from 114 records at S4 shaft tunnels and 79 records at S12 shaft tunnels were analysed statistically. Empirical relationships with correlation at the 95 % confidence interval were established for different rock units (diabase and arkose) and suggested for the test sites in order to estimate particle velocity of the ground vibrations.

Jan 1, 2007

By Eraldo Florêncio, Paulo Couceiro, Manuel Lopez Cano

Specialized marine blasting techniques were required to deepen and widen the access channel and turning basin of the Sudeste Port Terminal in Rio de Janeiro, Brazil. This terminal has been designed to handle the exports of iron ore and other bulk solid cargoes to international markets. The Sudeste Port Terminal is connected to the iron ore quadrangle in Minas Gerais State by a dedicated railway line, giving Brazil’s independent miners a seamless access to global markets. However, the Sudeste Port Project is located in a protected marine environment. Blasting in this area has required a comprehensive blast induced ground vibrations monitoring and analysis program to ensure the safety of the sensitive structures surrounding of the blast areas. Nevertheless, the risk of generating higher ground vibrations on nearby structures due to the combination of short distances, larger excavations layers and complex geology, increased the complexity of the blast due to the limitations imposed by the maximum instantaneous charge and a demanding project schedule. Site-specific test blast programs were planned and executed in order to obtain in-situ vibration data to establish the local attenuation law, and also to better understand the role of dominant frequencies before production blasting started. This paper summarizes the main findings and solutions applied during the marine blasting project in the Sudeste Port Project.

Jan 1, 2018

By Tom Treleaven, Andrew Williams

The town of Greenwich, CT, an exclusive suburb of New York City awarded several contracts for the installation of sanitary sewer in the North Mianus section of town. The Valley Road section was the most challenging from a rock excavation standpoint. The cut was up to 14 ft (4.25m), with adjacent utilities [20 in. (500mm) water, 6 in. (150mm) water and 8 in. (200mm) gas] located to within 5 ft. (1.5m) of the proposed sewer trench. Rock types varied but were ultra metamorphic in nature, ranging from quartzites, granite gneiss and various types of migmatities.

Jan 1, 2004

By B Brown, P J. Hommert, B J. Thorne

"Early attempts at estimation of stress wave damage in blasting by use of finite element analysis met with limited success due to numerical instabilities that prevented calculations from being carried to late times. A"" improved damage model based on microcrack growth in tension allows finite elementcalculations which remain stable at late times. Estimation of crater profiles for blasting experiments in granite demonstrate successful simulations with this model."

Jan 1, 1990

By Joshua Hoffman, Braden Lusk, Kyle Perry

This study explores how different geometries affect the shock tunnel’s performance and is broken down into three phases. Phase 1: Open arena testing in which theoretical energies produced by the detonation of small (<1.0 kg) charges are compared to actual experimental values. Phase 2: Shock Tunnel testing in which realized energies are experimentally recorded for the UK and S&T shock tunnels. Phase 3: Analysis of the data to begin building a pressure-forecasting tool for the UK shock tunnel given the explosive characteristics, sample size and desired pressure and impulse.

Jan 1, 2009

By Wawa Jaka Sungkawa, Slamet Rachman Jaka, Tom Dermody

Nowadays, with such a focus on environmental protection, surface mining activities have come under pressure to ensure their activities do not adversely affect the local surroundings. As part of the extractive process, blasting activities are an integral part of a mining company’s operational cycle. Consequently achieving beneficial blast results while complying with environmental requirements has become a key focus. This especially is the case when firing blasts within close proximity of residents where additional control measures need to be implemented to control vibration. One case where this occurs in Indonesia is in the Paringin Pit, one of the operational areas of the company's. The pit has complex geological conditions and is surrounded by several residential areas. Between 2014 to 2017 there were 12 cases of ground vibration exceedance due to blasting. As part of a continuous improvement project the company's targeted minimizing the vibration exceedance in this area. A project was undertaken to research and develop a method to confidently predict vibration. It was decided that the scaled distance formulas were not adequate to predict vibration when using non-electric detonators, as accurate wave propagation could not be achieved. The problem is how to manage of complex geology condition related with wave propagation in ground vibration control. Geological condition mapping with specific spatial range can and combine with Signature Hole Analysis be a solution to make wave propagation easier to accommodate in ground vibration control. With this new approach geological condition mapping with specific spatial range was produced that would minimize vibration while ensuring beneficial blast results. Introducing the new prediction produced nil cases of vibration exceedance in 2018 and beyond and proved that the Signature Hole Analysis in specific spatial range of geological condition is the preferred method to optimize blast result and maintain vibration control.

By Paul Downing

A typical day for a blasting company includes what seems to be an infinite list of tasks dealing with numbers. Whether determining the exact amount of explosives material in inventory, the number of holes in the shot, the exact distance from the blast site to the nearest exposure, or the capacity of bulk hoppers, the accuracy of numbers is key to ensuring the safety of the public, property and personnel.

Jan 1, 2008

By Kush Patel, Gary Cavanough

Mining operations consume over 2.5 Billion Australian dollars’ worth of bulk explosives annually (Richardson, 2018). Despite the large volume of product used, current practices only conduct a cup density test of the product being used. Explosive products are made up of a number of components, each with an effect on the performance of the explosive. This paper presents methods currently available for the evaluation of bulk explosives and discusses the results of the evaluation of bulk explosives using each of the methods. Through the preliminary experimental analysis, wet chemistry and the Bulk Explosive Analyser were found as methods most suitable for the evaluation of bulk explosives. This paper also presents data obtained from the experimental comparison of the wet chemistry method and the Bulk Explosive Analyser. Through a total of 60 tests carried out on 10 different bulk explosive products the average error of each method was determined, the BEA presented an average error of 0.11%, whereas, the wet chemistry method presented an average error of 1.90%. This is a significant difference when considering the importance of formulation of explosives. Further investigation into the capabilities of the BEA are also presented in this paper.

By Felix Torres

CVRD is one of the largest mining companies in the world. Adoption of new technology and improving operational efficiency are top company priorities. Initiatives in these areas have driven continuous company growth and an increased share price. During the first half of 2001, the company had a net profit of nearly US$ 500 M.

Jan 1, 2003

By Frank Hirthammer

"Nowadays, security in the lifecycle of explosives is more important than ever. Terror attacks all over theworld pushed the EU to decree a Commission Directive for the identification and traceability of explosives that set a series of requirements for involved manufacturers, distributors and end-users. The challenge was to find and implement a track and trace system for all concerned European companies byApril 5, 2015. Since then, countries worldwide have followed this example and implemented similarregulations."

Jan 1, 2017

By Vic Sterner

As cities and towns continue to grow, the need to install sewer, water, gas and other utilities becomes a necessity and the blasting of trenches for these service lines probably constitutes one of the most important forms of blasting in built-up areas. There f o re, understanding how explosives can be safely used in the most efficient manner is of prime importance. The need for protection against flyrock must be emphasized. The first consideration is that all explosive c h a rges should be located well down in the blastholes. The golden rule is to ensure that the depth of top stemming is never less than the burden on the hole. In the case of shallow holes, the minimum depth of stemming should not be less than 18 times the charge diameter, if airblast and flyrock are to be controlled. If there is a doubt, then additional cover and/or blasting mats should be used. Putting too much burden on blastholes is another possible cause of flyrock and raising ground vibration levels. Overburdening of explosive charges will also result in the blastholes not breaking to grade. This in t u rn re q u i res additional drilling of shallow holes down in the trench to achieve grade, thus further increasing the h a z a rd of flyrock .

Jan 1, 2004

By Jose a. Sanchidrian, Ramon G. Eguren, Javier L. Amigo

On December 2013 a MEMU exploded at a blasting site in Norway, after burning for more than two hours. This paper describes the analyses made to determine the actual yield of the explosion, the lessons learned from the event and the actions taken as a consequence. The conclusions of the analysis were the following: - The yield of the explosion was 650-1450 kg TNT. In terms of AN and ANE they correspond to 1300 – 3700 kg AN, or 950 – 2450 kg ANE or ANE/AN blend. These quantities are 8 to 31 % of the explosive precursors in the truck. The burning of the truck and its load for two and a half hours had consumed more than two thirds (perhaps up to 90 %) of the explosive precursor material.

Jan 1, 2016

By Nobel Insurance Service

[Executive Director’s note: ISEE is committed to continuing its efforts to ensure that blasters be made aware of the issue of migration of carbon monoxide resulting from blasting operations. In the July/August 2001 issue of the J o u rnal we printed excerpts from “Carbon Monoxide - The Silent Hazard,” an article from the Safety Update, published by Nobel Insurance Services. We also re minded readers of the text from the 17th edition of the ISEE Blasters Handbook in its section on trench blasting as follows: “...consideration must be given to the proper venting of gases generated from the blasting. Should those gases spread laterally rather than vent directly to the surface, the gases may travel underg round and finally vent well outside of the planned area. Such events may be caused by the strata, soil conditions or root systems, or existing and/or abandoned utilities or other man-made structures. In the worst situation, gases resulting from the detonation such as CO2, CO, and/or N Ox may travel through the strata and find their way into basements of nearby homes or businesses.” While incidents are rare, a number of cases in re c e n t years have resulted from outdoor blasting operations p roducing carbon monoxide gas that has migrated t h rough the earth and accumulated in nearby enclosed spaces. T h e re are steps that a blaster can take to be proactive in preventing incidents. These steps and studies of the occurrence have been expertly presented in several papers presented at ISEE conferences and included in the ISEE Conference Proceedings, available th rough the Blasters Library. In addition, Material Safety Data Sheets provided with explosives used in surf a c e blasting should provide additional information on gases p roduced by detonation. Below, we have reprinted the IME white paper, entitled “Fumes from Blasting Operations.” The paper underscores the unique set of circumstances that combine to contribute to high concentrations of CO measurements in underground, enclosed spaces following the detonation of explosive materials and provides recommendations to blasters

Jan 1, 2004

By Joseph A. Meyers

Explosives techniques and technology are constantly evolving and improving, yet basic communication and business skills are not being used regularly. Many potential blasting projects never occur due to simplistic, basic factors, such as a lack of communication. Articulate communication is the key component in the blast approval process, which has changed remarkably from how business was conducted fifty years ago. Imperative to the approval process is communication outlining the safety and benefits of the blasting project.

Feb 1, 2020