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By Gustavo Huerta Valer, Jorge Cárdenas Miranda, Johan Salas Flores

One of the challenges of mining is the optimization of the blasting process, which has an important impact downstream in the processing of crushed ore in the plant, that is why mining companies ensure the results of granulometry obtained from the blasting process through a joint work with companies specialized in the process of loading with explosives.

Feb 6, 2023

By Greg Shapiro, Paul Dr. Worsey

Mining, quarry, and construction blasts are becoming more and more dependent on bench profiling. The use of accurate profiling gives the blaster better data for the most efficient blast results. So, we ask the question: What is the best method for measuring and analyzing burden?

Jan 1, 2019

By Jeffrey Meissner, Mike Waldron, Charles Dowding

Most studies of crack response have focused on opening and closing of a crack in the plane of the wall in which the crack occurs. Crack movement also occurs perpendicular or normal to the plane of the wall. This paper will examine and compare the in-plane and out-of-plane (normal) response of cracks in two different residences near limestone quarries. In two locations, sensors that measure in-plane and normal displacement were installed side-by-side on the same crack, allowing direct comparison of the two modes of response. In a third location, a perpendicular pair of displacement sensors was installed in a corner of a room to observe the bidirectional response of the structure at a corner. Both long-term and dynamic data were recorded with the same sensors; temperature, humidity, and air over pressures were also recorded to compare blast and weather effects. Measurements show that ratios of out of plane to in plane response to dynamic events can vary. However, the ratios of out of plane (normal) response to vibratory events to that of climatological change is still as small as the ratio for in plane crack responses.

Jan 1, 2010

By T. G. Sitharam, P. B. Choudhury

Prediction of ground vibration (peak particle velocity, PPV) and frequency is an important task in geoscience. Till date, many empirical equations are derived from conducting trial blasts in the mines, to arrive at attenuation predictors. These predictors are usually site dependant and hold good for one particular type of rock/strata. These predictors cannot be used for geologically different rocks/strata. This paper presents the application of support vector machine (SVM) model, for predicting blast induced ground vibration and frequency, using a one comprehensive model for three different types of rock. Inputs to the SVM model formulation involve twenty one parameters consisting of geotechnical properties of the rock mass, blast design geometry and explosive properties, and the output of the formulated model is peak particle velocity and its associated frequency. The data has been acquired from eight limestone mine, five coal mine and two manganese mines. The comprehensive SVM model is formulated using 400 datasets and tested with 143 datasets. The performance indicators to the model not only justify its formulation but also the advantages it has over site specific predictor models. The SVM model not only predicts PPV, with higher correlation coefficients as compared to predictor equations, but also the associated frequency.

Jan 1, 2010

By Josee Boudreau

Transport Canada has regulatory requirements that pertain to the transportation of explosives. An important component includes the requirement for an approved Emergency Response Assistance Plan (ERAP). The ERAP may be traced to the recommendations made by Justice Grange following the enquiry into the Mississauga train derailment of December 1979. Justice Grange recommended that any shipper of dangerous goods must have a plan to control any release of dangerous goods in the event of an accident, and that the plan must be submitted to the Minister and approved by the Minister or by an organisation or person designated by the Minister. The right to ship could be withdrawn at any time if the plan is found inadequate either in its conception or in its operation.

Jan 1, 2010

By Sami Kara, Yunseok Park, Seung-Joong Lee, Namsun Hwang, Michael Laing

This study conducts a comparative analysis of construction efficiency. In the first part we compared electronic and non-electric initiation systems, focusing on tunnel contour holes. Field blasting operations were executed across a variety of delays to identify the optimal delay time. This delay for the in-situ rock mass was determined through regression analysis of blasting vibration in contour holes and for overbreak/underbreak. The blasting results with the electronic initiation system using the obtained optimal delay, applied to contour holes, were compared with the results of the non-electric initiation system. The overbreak and underbreak decreased by an average of 2.7 cm and 5.8 cm respectively, by using the electronic initiation system. Moreover, the vibration reduction rate in contour holes region was reduced by 11.9% based on the blasting vibration estimation equation proposed by the Ministry of Land, Infrastructure, and Transport (MOLIT). Underground construction projects have become increasing popular as cities grow in both size and density. This growth severely limits the amount of useable space for new project on the surface, resulting in the decision to build them underground. This new policy however brings into focus the challenge of managing and reducing blasting related vibration due to the proximity of these projects to sensitive structures, utilities and foundations often present in urban environments. For this purpose, we have been required to manage the vibration by reducing the quantity of explosives used per round. Inspired by surface blasting techniques, we applied a decking mode to address and work around this challenge. We present in this paper the first attempt to blast a tunnel face using a decking method and reduce the charging per hole from 6 kg to 3 kg per hole and keep the same advance rate for this tunnel. The results are presented in the third part of this paper. In the second part we present the results of the decking mode in shaft. The use of the electronic initiation system in tunnel construction provides the users an effective tool to improve the overbreak/underbreak and keep the vibration at a low level with a large gain on the overall project schedule and budget. This what we want to demonstrate in this paper.

Jan 21, 2025

By Jim Smith, Jeff Hudreth, John White

Jan 1, 2000

By Dale S. Preece, Ruilin Yang

Shock wave physics is an important part of air-deck behavior since the bulk explosives in the column impart a shock into the air-deck where the air shock then passes through the air-deck at a rapidly attenuating velocity. Through both high-fidelity modeling and shock physics theory it is shown that the resulting pressure in the air-deck is two orders of magnitude less than the detonation pressure of the explosive. The induced air blast reflects from the bottom of the borehole and this reflected pressure, even though doubled, is still approximately two orders of magnitude less than the detonation pressure. Air-shocks will ring back and forth in the air-deck for a few tens of milliseconds while the adjacent explosive column(s) are detonating. Transmission of the initial shock through the air along with reflections is an intensive energy consuming process. Energy balance results in shock heating of the air and a temperature increase. However, the increased temperature of the air is also orders of magnitude less than that of the explosive detonation products immediately behind the detonation front. Replacing high energy explosives with zero energy air-decks in a blasthole will always have a negative impact on the adjacent rock fragmentation and movement.

Jan 1, 2016

By Italo Onederra, Miguel Araos

"In order to characterize non-ideal explosives, the explosives industry rely on unconfined velocity ofdetonation tests and where possible underwater pond tests. The information obtained from such tests isquite helpful, however it cannot tell us much about the dynamics of the detonation reaction process. The detonation process has been studied for ideal explosives and the reaction zone length have been measured. However, for non-ideal explosives, that type of information is not available. Therefore, the primary aim of this work was to capture the detonation process of a non-ideal explosive using high speed video camera to determine the zone length."

Jan 1, 2017

By Shazad Hosein, William J. Birch, Robert Farnfield, David Jameson, Catherine E. Johnson

The current and consented quarry workings at a slate quarry in North Wales {UK} intersect old long abandoned underground slate mine workings. The old underground slate mine contains the remains of World War II buildings used to house artworks to protect them from war damage. Over the past 20 years, there have been a number of roof falls in the old underground slate mine, which have damaged the buildings and make general access unsafe. From observation of the timing of these falls, they occurred in the mid 2000’s. The purpose of the exercise was to determine the possible relationship between blast vibrations experienced on the surface and those experienced on the roof of the abandoned mine caverns. Thus preventing the need to regularly monitor in the old mine workings. In order to achieve this, a rigorous geotechnical assessment of the stability of the caverns was undertaken by a fully qualified Geotechnical Engineer. Once it had been determined that it was safe to do so, 3 “MEMs based” blasting seismographs were attached to the roof, in accordance with the instruction of the geotechnical engineer. In addition, 8 “MEMs based” blasting seismographs were deployed at various locations on the surface. The trial blast comprised of 51 blastholes, with charges varying between 46kg [101lbs] and 124kg [273lbs] of bulk emulsion explosive. The blastholes were in 4 rows of holes. The blast was connected using shock tube 25ms, 33ms and 65ms delay period relay detonators. The minimum distances from the blast to the surface and underground monitoring points were 78.1m [256 ft] and 114 m [374 ft] respectively. The results from the three underground monitoring locations in terms of resultant peak particle velocity was 4.42 mm/s [0.174in/s], 3.47 mm/s [0.137in/s], and 4.69 mm/s [0.185in/s]. In line with previous research, it was determined that the underground results [when compared on a “like for like” basis in terms of scaled distance] were lower in amplitude than the surface results. In this case by a factor between 0.47 and 0.87, averaging 0.68.

Jan 21, 2025

By H. Wallin, I. G. Wallace, J. Akhavan, E. Nilsson

Over the past three years the UK together with Sweden, Norway, Finland, Italy have been taking part in a EU funded Leonardo da Vinci programme. More recently EFEE have participated in the project known as the EU15/10/200715/10/2007Excert project which is aimed at addressing the perceived loss of explosives expertise in several EU nations. This could have implications for explosives safety and industrial competitiveness. The paper outlines the work that has so far been done in phase 1 and describes the work planned for the second phase of the project. The paper will describe work in the UK to develop competencies for all explosives workers in both the civil and defence sectors. These competencies in the form of National Occupational Standards have now been approved in the UK and are accompanied by a range of 24 new National Vocational Qualifications launched in May 2006. The paper will show how the standards define knowledge and skills and how these form the basis for vocational qualifications as well as higher education awards and professional qualifications. This UK initiative is now being considered in other EU countries and the project has now been extended to also include Germany, France, Portugal, Czech Republic, Lithuania and Estonia. To support the occupational standards and qualifications work is also being carried out to improve learning provision in the explosives area. In addition to formal educational and conventional training courses a series of workplace learning initiatives are being pursued as well as internet learning packages. Examples of these initiatives will be given.

Jan 1, 2008

By Erica Lorenzo García, Benjamín Cebrian Romo, Antonio Morato Medina

This paper presents the results of a preliminary study on blast-induced vibrations conducted at a Radioactive Waste Storage Facility, located in Spain. The study was undertaken as a preparatory step prior to the blasting operations required for the construction of a new platform located near critical infrastructure housing very-low, low and intermediate-level radioactive waste. The primary goal was to establish a site-specific vibration attenuation curve to safely determine allowable explosive charges based on their distance to sensitive structures. The study followed the criteria defined in the UNE 22.381-93 standard, which regulates permissible vibration levels for different structural typologies. In this case, the existing facilities were classified as Type III structures, given their heightened sensitivity to vibrations. Two experimental campaigns were conducted. Test 1 consisted of a series of 10 individual blasts with increasing charges, monitored by five strategically placed seismographs to record seismic wave propagation and determine the attenuation parameters via regression analysis. Test 2 simulated a production blast using operational charges of 41.7 kg (91.93 lb), applying different delay sequences (42 ms and 25 ms) between holes to assess wave interference, resonance, and constructive effects. Data analysis showed that the longitudinal component dominated vibration transmission, and the predominant frequencies in the most critical zone ranged between 18 and 20 Hz. Based on these values, a conservative peak particle velocity (PPV) limit of 4.75 mm/s (0.19 in/s) was established for blast design. The recorded vibration levels during the tests remained within regulatory limits, with maximum values of 2.35 mm/s (0.09 in/s) and 2.86 mm/s (0.11 in/s) for the sequenced blasts, and peak acceleration of 0.0464g.

Jan 26, 2026

By Jason Baird, Joshua Hoffman, Phillip Mulligan

The purpose of this report is to address the method of reducing the overall explosive weight of Explosively Formed Projectiles (EFPs) while still achieving satisfactory performance. This reduction is crucial in order to comply with outdoor explosives testing standards for Missouri University of Science and Technology’s (Missouri S&T’s) Experimental Mine. Initial EFP design testing exceeded given limitations, making reliable data difficult to ascertain. EFPs must be tested outdoors to allow for specific information recordings which aid in defending against them.

Jan 1, 2010

By Cesar Guerra, Alejandro Rojas, Dr. Jhon Silva, Luis Velasquez

The ANN method is applied to predict the P_80 size in one open pit gold mine in Peru. The ANN was implemented in Matlab programming language, and the results from the ANN are compared with data obtained using photo-fragmentation analysis software.

Feb 1, 2020

By Jaime Herrero, Santiago Gómez, Pablo Segarra, José Ángel Sanchidrián

This paper presents a mathematical model for the study of the 2D movement of blast bench faces based on the high-speed video analysis of three blasts at El Aljibe quarry (Spain) recorded at 2,000 frames per second. In these blasts, a set of bags of 0.75 × 0.75 m were placed in front of a selected blasthole defining a reference plane in which to study the kinematics of the movement. The burdens range from 3.86 m to 5.54 m, with a bench height of 12–13 m. An affine transformation system was calculated to convert coordinates from the video images into actual spatial coordinates. The problem is established from a multi-objective minimization approach in order to simultaneously optimize two defined objectives: trajectory fitting using Total Least Squares regression, and time–displacement regression using Ordinary Least Squares. Muti-objective minimization formulation produces Pareto plots of non-dominated solutions, i.e., optimal combinations of initial velocities and response times, (i.e. time between detonation and the onset of bench face motion). From the Pareto frontier, the most balanced solution is selected. Blast response time lasts only a few milliseconds and appears so brief at the frame rate used that it is difficult to detect visually. In this context, the bi-objective optimization-based approach proves to be a more robust tool than frame-by frame survey for quantifying such a rapid event while also maintaining a strong performance in the trajectory fitting task. Root Mean Square Error (RMSE) for the two minimizations average 0.22 m and 0.13 m, respectively. The initial velocities obtained range from 4 to 17 m/s, and the response times 0.7 ms to 21.7 ms. An analytical model is also presented for predicting fragments initial velocity and response time as functions of blast geometry and rock mass properties, explaining approximately 87% of the total variability.

Jan 26, 2026

By Rachel E. Gooding, George C. Emmett, David R. Bradley

The United States (U.S.) Department of Homeland Security (DHS) Directorate of Science and Technology (S&T) is using a probabilistic risk assessment (PRA) approach to evaluate the risks from terrorist use of explosive materials against the Homeland. A similar approach is currently being used to evaluate the risk from terrorist use of chemical, biological, radiological and nuclear materials.

Jan 1, 2017

By Kush Patel

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.

Feb 1, 2020

By Raúl Carretero de la Hoz, Leonardo Soares Chaves, João Paulo Soares Toneli, Francisco Felipe da Silva Dantas, Marcos Peres Lopes, Marcus Vinicius da Silva Gonçalves

The mining activity results in environmental impact and thus requires the adoption of techniques to minimize its effects. The rock blasting process is required to break up and move the rock enabling the haulage of the material, however, it might also cause undesirable effects such as flyrock, overbreak, excessive ground vibration or air-blast at the neighboring communities and damage to civil or geological structures located nearby. The Serra Sul mine, commonly referred to as S11D project, has obligations to preserve two natural tropical montane lakes and several maximum relevance natural cavities whose legal preservation radius represents constraints to the mine development and operation. Controlling measures are undertaken to ensure preservation of the cavities, especially during rock blasting stage, with limitations of the maximum instantaneous charge (MIC) and ground vibration control. The demand for high productivity and the large areas with hundreds of blastholes to charge are challenging factors to the charge control. This work presents the development and field application of a map for limiting explosive charges in the rock blasting process at the Serra Sul mine, used for the definition of maximum charges according to the blast location, ensuring the preservation and compliance with the defined ground vibration limits for each cavity. The map is applied at the mine for every blast and when there is a charge constraint, the map helps to define the areas with different charging profiles in the field contributing to higher charging productivity.

Jan 21, 2025

By Paulo C. Fernández A, Sergio Matamala V, Claudio C. Gajardo, Christian A. Rees P

In fragmentation processes in open-pit mining, it has been observed that there are many opportunities for improvement if greater control of ore displacement in blasting is achieved, reducing the percentage of mixing between ore and waste material (dilution) through the integration of new technologies that allow its quantification and optimization of extraction polygons. This work investigates the relevance of the initiation sequence and direction of displacement in blasting in relation to ore dilution and the potential benefits of process optimization. A three-dimensional modeling tool was used to evaluate movement control optimizing the extraction zone based on the maximization of ore recovery. The study was made by iterating different scenarios, by varying only the initiation sequence and inter-hole delays. To validate the displacement simulation, a total of 10 blasts were carried out for calibration, obtaining a level of agreement between the simulation surface and the actual topographic survey of 80% or higher. The analysis included horizontal and vertical displacement, quantification of swell and dilution within extraction polygons for different scenarios, and informed decision-making based on ore control. The results clearly indicate that by modifying the blast initiation sequence, greater control over dilution in ore/waste transition areas is achieved, thus optimizing the recovery of the planned material and maximizing the ore grade. The use of this type of simulation tools allows for the generation of extraction strategies based on the value of the polygon, unnecessary displacements in the free face, optimal loading fronts, etc., maximizing the recovery of ore and stockpile material, complying with the planned tonnage and ore grade for each extraction polygon, delivering added value to the chain and emphasizing the importance of adding new technologies to the mining industry that allow for the optimization of processes to maximize profits.

Jan 26, 2026

By Orica Peru, Pedro Lozada

Proper management of exclusion zones in blasting operations is essential to ensure safety without compromising operational efficiency. In Peru, mining regulations establish minimum exclusion distances specifically for personnel (500-meter radius / 1,640 feet), but do not define clear technical criteria for equipment. As a result, conservative distances such as 200 meters (656 feet) are often applied, negatively impacting productivity. This study proposes a technical-scientific methodology to reduce equipment exclusion zones, based on the use of advanced technologies such as drones, high-resolution cameras, and specialized software tools. The solutions used allow video recordings of blasts to be transformed into dynamic data through artificial intelligence and computer vision, as well as execute probabilistic simulations of the flyrock phenomenon using Monte Carlo algorithms and physical models calibrated to real operating conditions. Technological integration enabled the simulation of real operational scenarios, considering variations in critical blasting parameters that directly affect flyrock generation, such as drill diameter, explosive density, linear charge, and stemming height. Additionally, the Terrock methodology was incorporated, allowing the behavior of the rock mass to be included as a variable in risk assessment, improving analysis accuracy under different rock hardness conditions. The methodology was applied in four phases: diagnosis of the current design (15 blasts), modeling, validation of the calibrated model (6 blasts), and subsequent operational implementation. As a result, it was determined that the exclusion radius can be safely reduced from 656 to 492 feet (200 to 150 meters), maintaining as the main restriction the use of stemming lengths greater than 5.0 m. This optimization has the potential to generate tangible benefits, with estimated monthly savings exceeding USD 50,000, associated with reduced evacuation times, lower fuel consumption, less equipment wear, and increased productivity in drilling and hauling activities. The comprehensive approach presented here highlights the transformative potential of digital technologies applied to blast management, contributing to safer and more efficient mining operations.

Jan 26, 2026