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By Robert Hopler

Although electrical instruments were being widely introduced into the study of seismic tremors, attempts to understand and quantify shocks from blasting continued to use rather primitive methods well into the 19th century.

Jan 1, 2007

By Nikolaos Petropoulos, Changping Yi, Daniel Johansson, Håkan Schunnesson

The effect of jointing on fragmentation by blasting was investigated experimentally and numerically. Firstly the experimental results were presented. Then the numerical modelling based on the experiments was performed. The same conclusions can be obtained based on both experiments and numerical modelling.

Feb 1, 2020

By Davey Bickford, Johan Hawinkel

Blasting and the use of civil explosives are a critical step in the mining process. Good decisions provide significant downstream benefits and create a safe and sustainable working environment, while poor decision making and judgement can have catastrophic consequences on workers safety, critical infrastructure or the security of the general public. An ever-tightening regulatory framework increasingly exposes manufacturers, transport companies and mining companies to the consequences of breaches resulting from erroneous or ill-informed decisions. In this context, new capabilities are required providing all actors in the explosive supply chain with tools to make better informed decisions allowing the individual to own up to his or her decision. Additionally, the traditional risk-control approach in the explosive supply chain up until usage and waste elimination, through administrative control procedures and processes, is becoming increasingly inadequate. In this era of digitalisation and automation, technology will play a pivotal role in ensuring safety and security in storage, transport and usage of civil explosives using the latest advances in electronics, communication technology and information technology. This paper explores the journey through time of technology in the civil explosives market to provide testing, measurement, analysis and control tools. This ultimately leads to better decision-making, ensures full accountability of the decision maker and uses the same technology to review decisions for process improvement, in the settlement of disputes or for the investigation of incidents. Additionally, the paper discusses the application and integration of electronic and digital technology in explosives and initiation systems as engineering controls for blasting associated risks. Finally, this paper reviews two practical cases of technology integration for risk management and improved decision making; the use of integrated GPS technology in initiation systems as an engineering control in the blast evacuation process and the use of RFID technology in explosive tracking from cradle to grave.

By Thomas E. Ricketts

Occidental Oil Shale Inc. has spent the last eight years at its Logan Wash. mine near DeBeque, Colorado, developing its modified in-situ oil shale process for obtaining oil from oil shale. Modified in-situ technology involves large underground chambers, or retorts, which are formed by mining out a minimal volume of rock to allow explosive expansion of the surrounding rock into tile mined void volumes. The resulting rubblized retort volume must contain a fairly uniform particle size distribution and void distribution to permit maximum oil recovery during subsequent in-situ processing operations. The more uniform the rubblized volume of particles, the more oil recovery obtained during processing. The processing involves first igniting the top of the retort and then. injecting air into the top of the retort to drive the combustion front downward through the entire rubblized volume. The oil is continuously collected at the bottom of the retort during the processing.

Jan 1, 1981

By Ali Kahriman, Olivio Angelini, Ibrahim Sefer, Burak Ekmen, Koray Arpak, Ertugrul Kaya, Yucel Karakus, Abdullah Sak, Aziz Ozdemir

In recent years, in order to bring solution to traffic intensity arising from transportation problems and facilitate public transportation in the modern world in paralel to urbanization and to the increase in population, it’s well known that, the construction of Access tunnels is inevitable. The driving of the tunnels is a subject of special interest in the technique of rock blasting. The essential factors in terms of tunnel driving and safety in tunnel blasting that is applied in metropolitan areas, an in depth knowledge of ground vibrations and the ways of reducing them to safer levels.

Jan 1, 2010

By Alan Hooper, James E. Mischler

Construction began in 1984 for a 5 megawatt hydroelectric power retrofit at the O'Shaughnessy Dam for the City of Columbus, Ohio. The construction necessitated excavation of limestone bedrock up to 27 feet below the normal water level of the river downstream of the dam. Proximity to the river and difficult terrain resulted in an interesting and challenging construction project.

Jan 1, 1986

By D. Rudenko, C. T. Aimone-Martin, J. K. Ratliff, I. G. Wong, J. Aiken, R. E. Burnham, T. A. Davidsavor

A small quarry blast was conducted with a maximum of 90 pounds per delay and shortly afterwards, area residents sensed ground motion and building shaking indicative of an earthquake. In addition, seismometers up to 500 miles (800 km) away recorded a magnitude 2.8 earthquake located in the area. Positioned in a seismically inactive area, southern Minnesota is not known for earthquakes. The earthquake was originally described by the USGS to be a surface blast at the quarry. Analysis showed that the earthquake occurred shortly (approximately seven seconds) after the quarry blast some distance away and well below the surface. This paper describes the evaluation of the “seismic events” including the blast, the following earthquake, initial governmental response, and provides the framework for assessing the relationship between the blast and the earthquake. The paper also discusses management of large volume claims from a complex event and presents a claims management strategy with best practices.

Feb 6, 2023

By Kia Riihioja, Mike Higgins

A major difference between electronic and pyrotechnic detonators is that, in almost all but the simplest of blast layouts, computer software is required to plan a blast using electronic detonators. While it may be possible to program delay times without software, using only the manufacturer’s control hardware, the full potential of electronic detonators can only be realized through software. Until recently, the only software available has been provided by the suppliers of the electronic detonators. These usually have just enough features to create a hole layout and to assign times to the detonators in the holes. The software is also able to communicate only with the manufacturer’s detonators. This means that the client may be compelled to change several parts of the blasting process when a different delay system is adopted, from design through to implementation and reporting, even though these may be sub-optimal at the client’s mine. While many authors have demonstrated improvements in blasting outcomes using electronic detonators, very few have discussed how the delay times were calculated. Where the calculations are discussed, it is also obvious that the delay times must be monitored and re-evaluated as conditions in the mine change. For example, the principles of superposition and scaled distance, burden relief and energy cooperation between holes should be checked constantly for different locations within the mine, changes in rock properties, or even for differences between design and actual hole positions. The most common methods in blast design software to calculate delay times are inter-hole interval, relief contour and direct editing. Although they are simple in concept, they can result in fundamental errors if they are not applied correctly. The software for electronic blast designs should be capable of not just a timing calculation, but also of showing, to some degree, the impact and interaction of the calculated times.

Jan 1, 2004

By M. S. Dotto

The knowledge of the explosive/ rock mass interaction process is important in predicting blast performance. It includes understanding rock properties, energy usage, and attenuation in the rock mass. The paper proposes a method to quantify blast-induced rock mass damage from the field measurements and apply it to modeling blast fragmentation.

Feb 1, 2020

By Steven Richardson, E A. Cameron, Reza "Ray" Jambakhsh

This paper outlines the design and implementation of a method to use Long hole Carbide drilling to blast an "Upper Blind Slot Raise" in the range of 12m (40 ft).

Jan 1, 1992

By Clara Godoy, Álvaro Dapía, Paulo Couceiro, Pablo Segarra, José Ángel Sanchidrián, Juan Navarro

This paper applies geostatistical tools in Measure While Drilling (MWD) data to estimate the probability distribution of values in all the points of the studied domain in order to assess the continuity of rock classes between boreholes. The analyses carried out by Ghosh et al. (2018) and Navarro et al. (2019) have been used as starting point of this work to classify the geotechnical rock condition in four classes: solid rock, fractured rock, cave- in rock and cavity. From it, an application for the geotechnical rock condition of orebodies have been developed, aiming at characterizing the rock before the charging the holes to minimize unexpected rock conditions and to address issues associated with charging and blasting operations. Such problems are closely related with non-optimal rock fragmentation after blasting.

Feb 1, 2020

By Denard Brandt, Isidro Martinez, Greg Baker, Laura Slattery, Teddy French

The Dos Pobres Mine is a copper oxide heap-leach mine located near Safford, Arizona. Mine production is 180,000 tons (163,293 tonnes) per day with a stripping ratio of 2:1. During the startup phase of the mine, the required fragmentation size was easy to achieve as the ore was highly weathered and fractured near the surface. As the mine depth increased, the proper fragmentation size became harder to achieve due to less weathering and different rock types. Because copper recovery increases as crusher product size decreases, achieving the appropriate product size at the crusher is the operating priority.

Jan 1, 2010

By Scott King, Norm Patterson, Ruilin Yang

The multiple blasthole fragmentation (MBF) model developed by Orica models the contributions from multiple blastholes to fragmentation at any given point in the rock and simulates a production blast with the actual geometry of the blasted overburden and free faces, explosive loading, multiple decking, and delay timing of each explosive charge. The model has been successfully applied to several open pit mines and quarries around the world, including Canada and the United States. The peak particle velocity (PPV) induced in the rock from the explosive detonation is used in the MBF model as the key parameter relating to the size distribution of the rock fragmentation. Relating the PPV to the rock fragmentation is based on earlier work relating the particle velocity to the dynamic strain in rock. A recent publication further revealed that the PPV is related to the maximum relative displacement that induces three dimensional strain at a point in the rock. The model can explicitly model most of the blast design parameters including explosive properties.

Jan 1, 2018

By Jacqueline Berendzen

Summer internships are a great way for students to explore different career paths in the industry and get first hand experiences with potential employers. As a junior in mining and explosive engineering, my 2009 summer internship gave me a behind the scenes view of the actual workings of an explosive company and the role they play in the mining industry.

Jan 1, 2010

By Tyler Rockley, Cara Rosen

Blasting at a granite quarry in eastern Maryland produces elevated air blast readings that can fall into the cautionary zone for the state of Maryland environmental regulations on a semi-regular basis. When designing blast patterns in this quarry, challenging geology creates rough and uneven blast faces that can be difficult to capture with 2D laser profiling fully. Utilizing several methods known to manage high air blast results like pattern adjustments, decking, and timing changes have not achieved consistent outcomes. Accurately capturing and modeling this geology is the key to controlling high air blast. 3D modeling and profiling by drone is the solution to understanding accurate face profiles and real minimum burdens. Using 18 months of blasting data and air blast results to establish a baseline, the comparisons between blasts designed with 2D profiling and blasts designed with drone 3D profiling show improvement in air blast levels. Additionally, shots with completed drilling were drone profiled to understand precise amounts of burden for each borehole. This 'audit' of a blast allows for custom loading of explosives, accommodating the amount of burden present on the blast face. 3Dprofiling is not a new tool in the blasting industry, but a drone alleviates some of the restrictions ground systems face. Controlling and managing air blast, as it pertains to face burdens, requires an understanding of those burdens from all angles. A drone provides that distinct level of insight. The results of this study indicate that drone profiling is managing the customer's air blast readings, allowing the customer to maintain their license to operate within the community.

By Tyler Rockley, J. P. Remi Proulx, Ruilin Yang

A highwall blast vibration project was carried out to quantify the level of blast vibrations produced from a trim blast in soft rock and a combined production and trim blast in hard rock. Combining production and trim blasts could be performed without exceeding the mine’s vibration limits.

Feb 1, 2020

By Auã Kiahla, Tomi Kouvonen, Vinicius Miranda

Through numerical mathematical processing (Taylor’s approach and numerical derivation) the original data supplied by the accelerometer’s sensors was transformed into velocity and, after the data mining, a statistics residue analysis was applied in order to evaluate if the data from the prototype and from the traditional seismographs were similar. The data from each system was used to estimate the attenuation law and the results are shown in this paper

Feb 1, 2020

By Walter Valery, Sarma Kanchibotla

Due to the global financial crisis, the world economy has turned upside down and most major economies in the world are facing severe recession for the past one and half year. During this period most commodity prices have tumbled by more than half from their peaks and such a sudden and severe economic downturn is not seen since the great depression. This sudden drop in commodity prices and lack of credit made many mining operations unviable and even those mines that are marginally viable at this point are operating under severe cost pressures and capital expenditure restrictions.

Jan 1, 2010

By Dale S. Preece

A new three dimensional (3D) mechanistic model of fragmentation, called the Fracture Density Model (FDM) is used to simulate full-scale bench blasts at the Bararp dimensional stone quarry in Sweden. The model uses several computational mechanics algorithms to simulate the effect of blasting in different rock types

Feb 1, 2020

By Jianping Li, Ernesto Villaescusa, Kelly Fleetwood

During blasting, stress waves propagate through a rock mass, inducing stress and strain changes. This applied deformation affects intact rock, existing discontinuities, mine excavations, and engineered structures in the proximity of the blast. Traditionally in blasting, stress waves are quantified in terms of peak particle velocity (PPV) or peak particle acceleration (PPA), based on the method of measurement and the specified allowable tolerances. During analysis, the peak particle motion is coupled with an explosive source through various scaling laws to develop rock-specific attenuation relationships. Some studies have expanded this practice to the development of damage threshold values based on measured or predicted peak particle velocities. PPV-related thresholds are generally based on empirical models, where observation of overbreak, cracking, or fall-off are used to quantify damage. This method is often paired with the application of elastic plane wave equations to calculate the blast induced strain or the PPV threshold for tensile rock failure. Other factors that must be viewed critically in such models are the methods used to collect and analyse blast vibration data and the application of inappropriate vibration attenuation relationships.

Jan 1, 2009