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By Randall Wheeler

In early 2008 we were asked by a quarry to become involved in a conflict with a pipeline company concerning blasting near one of their underground high pressure gas lines. The pipeline company, without the quarry’s knowledge, had sought and obtained a temporary restraining order against the quarry forbidding them from blasting near the pipeline.

Jan 1, 2011

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 P A. Lang, J G. Ayotte, R W. Humphries

Atomic Energy of Canada Limited (AECL) has the responsibility for research, and development of technologies, for the safe and permanent disposal of Canada's nuclear fuel wastes. As part of this comprehensive program, AECL is constructing an Underground Research Laboratory (URL) near Lac du Bonnet, Manitoba, to evaluate aspects of the concept of waste disposal deep in stable geological formations. No nuclear wastes will be used in the URL program.

Jan 1, 1986

By Alexandra Yuyali

The objective of this research work is to increase the drilling ratio represented in tons per drilled meter (ton/m) to reduce mining costs. One of the key characteristics of this research is the use of the ITH (in-the-hole) drilling rig with a water-powered hammer, also known as Wassara™. The patented Wassara™ in-the-hole hammer is powered by high-pressure water instead of air. To reach the objective, a new design of the blast pattern was implemented considering the following: Burden from 1.7 m (5.6 ft) to 2.8 m (9.2 ft) Spacing from 1.7 m (5.6 ft) to 2.7 m (8.9 ft) Drill diameter from 89 mm (3.5”) to 102 mm (4”) Drilling length from 15 m (49 ft) to 30 m (98 ft) Borehole deviation < 2% The result of this new design is the optimization of the drilling ratio (ton/m); having as a baseline 5.2 ton/m with traditional equipment and obtaining 13.7 ton/m with the ITH drilling, which generates annual savings of $2.43M.

Jan 21, 2025

By Earl Cook

With all our power and hope, we are part of the natural system and subject to its laws. As Francis Bacon pointed out long ago, we must understand those laws and "obey" them if we wish to "conquer nature." Bacon was saying that if we plan and engineer in compliance with nature's laws, we'll get a lot more out of the natural system than if we don't, because then we can use the system instead of fighting it.

Jan 1, 1979

By G. A. Walsh, M. Timm, S. M. Geerts

This paper will discuss the effectiveness and the general use of improvised shaped charges. Testing was conducted by the New Mexico Tech Student Chapter of ISEE and held at EMRTC. The first series of tests conducted was to illustrate the performance of different features of the shaped charge. A PVC pipe filled with C4 with no cavity, PVC with an unlined conical cavity, PVC with a copper lined conical cavity and no standoff, and lastly a PVC pipe with a copper lined cavity and a 1.5 cone diameter standoff.

Jan 1, 2010

By Scott G. Giltner, Alex Schwenk

Blasting within 250 ft of a crusher was successfully executed through the application of electronic detonators, 3-D imagery, signature hole analysis, custom loading of blast holes. The blast was well contained, the vibrations were minimal, and there was no flyrock.

Feb 1, 2020

By Richard Turnbull, James Purssey

"The Northconnex Project is a twin nine kilometre tunnel in Sydney, Australia, linking the M1 PacificMotorway at Wahroonga to the Hills M2 Motorway at West Pennant Hills. Access to the tunnels will befrom portals at either end and from three vertical shafts spaced along the length of the motorway. These shafts will provide access for equipment, plant and personnel, removal of spoil during construction,ventilation, and emergency egress points during tunnel operation. The three shafts have a 12 m x 16 m (39 ft – 53 ft) cross sectional area and depths ranging from 45 m to 91 m (148 ft – 299 ft). The vibration limit for the shaft blasting was set at 10 mm/s ppv, with residential properties as close as 31 m (102 ft) and the existing M1 motorway 80 m (262 ft) away. The traffic volume for the M1 is 80,000 vehicles per day and Northconnex will provide an additional 100,000 vehicle capacity. "

Jan 1, 2017

By Javier Illanes Pizarro, Gustavo Huerta Valer, Jorge Cárdenas Miranda

Bench stability is the basis of sustainability in an open pit mining operation. Taking care of the pit walls while maintaining fragmentation results can prove a challenge. In this study, technical proposals have been developed for extra hard rock mass (UCS>175MPa) with presence of unfavorable structural planes in high copper grade zones. The base case shows low compliance of fragmentation results and a significant loss in berm width, with over size boulders causing low primary crushing rates. Paradigms in current drill and blast design were overcome to improve fragmentation results and achieve objectives.

Feb 6, 2023

By G. C. Naveen

Punatsangchu Hydroelectric Project Authority is constructing 1020 MW underground hydroelectric project in Bhutan. The project envisages construction of concrete dam, Desilting Chamber, Head Race Tunnel, Power House Complex and Tail Race Tunnel. Tunneling is one of the major activity in any underground projects as they are driven for multiple activities. By and large the tunnels are a major part of connecting networks from surface to caverns/underground working sites. Many tunnels in hydropower project are part of water conducting systems and one such important tunnel is the Tail Race Tunnel in this project and had to be excavated in thinly foliated rockmass conditions by D&B method. The rockmass is traversed by three to four joint sets and few minor shear seams. Rock Class “Q” values were between III and IV. Tunnel was excavated by full face parallel hole drilling blasting method. The adopted blasting method consisted of drilling 45mm (1.77 inch) diameter holes to a depth of 2m and the drilled holes were charged with 40mm (1.57 inch) diameter cartridge explosives and charges were initiated with half second non electric initiators. The perimeter holes were drilled at closer spacing of 30cm (1 feet) and alternate holes were charged using 32mm (1.23 inch) diameter cartridges explosive. Low dipping foliation joints present in the rockmass tend to slab in crown portion and erratic occurrence of intrusive bodies lead to unpredictable behavior of rock mass posing a major challenge for the safe excavation. Stability was a major issue through controlled blasting under constant supervision too could not limit the overbreak in certain weak rockmass conditions thereby exposing cavities of about 2.5m (8.2 feet). The stabilization of these cavities and handling the overbreak due to rockmass condition was time consuming and warranted additional supports. With systematic measurements and controlled blast designs the Horse Shoe Shaped Tail Race Tunnel of 9.1 m (29.85 feet) diameter and 304m (997.37 feet) length to connect with Downstream Surge Gallery of 314m (1030 feet) length, 18m (59 feet) wide and 58.8m (193 feet) height in thinly foliated and jointed biotite gneiss rockmass was successfully excavated.

By Douglas Rudenko PG, Jay Elkin, Siavash Mahvelati Ph. D.

Very little studies have investigated the behavior of cracks in unlined tunnels over long periods of time, especially when such flaws are subjected to blast-induced vibrations. Using a pool of 30+ blast events, a positive correlation was found between the peak particle velocity and peak crack movement.

Feb 1, 2020

By Al Romphf

Managing blasting-induced air overpressure levels is a key compliance requirement for most blasting operations. Regression analysis, plotting overpressure amplitude vs cube root scaled distance, will often present a level of scatter which should be considered unacceptable. Relying solely on regression-based predictions can lead to overly conservative restrictions that may negatively impact other key performance indicators. Improved methods are needed for accurate overpressure prediction. The Heelan-Blair wavelet has been shown to closely resemble the overpressure waveshape produced when a single charge is fired under typical confinement conditions. The amplitude of a single-hole overpressure wave is influenced by factors such as proximity to the receiver, charge mass, orientation, and confinement both at the collar and face. Additional factors, including timing sequence, barrier effects, wind direction and velocity, must also be considered. The linear superposition method, commonly applied for ground vibration prediction, can be adapted for air overpressure modelling. In blast design software, this approach can consider all relevant parameters and environmental interactions. Given the uniform nature of air compared to rock, linear superposition using realistic elemental wavelets may replace the need to fire a signature hole. Data from 38 single-hole blasts conducted at quarries and mines throughout North America were used to develop and calibrate a linear superposition model. This model reasonably reproduces air overpressure results from full-scale production blasts, offering a practical approach to overpressure compliance and prediction.

Jan 26, 2026

By Lazar Kricak, Vladislav Kecojevic, Dragan Bogunovic

In spite of many advantages explosives have, their usage may cause environmental problem such as seismic vibration. One of the solutions to this particular problem may be application of an artificial screen as a barrier to the seismic wave path. This paper presents the results of experimental research on the artificial screen concept, its characteristics and role in attenuation of seismic effects generated by blasting. More than 1,500 laboratory measurements were conducted with different combinations of screen sizes, positions of the screen to blasting source, and intensities of blasting impulses. The results of the study show a significant reduction of generated vibrations by employment of artificial screens.

Jan 1, 2007

By Braden Lusk

The problem of predicting damage in densely developed areas due to incidental or malicious explosions is one of considerable importance to local, state, and federal governmental bodies. The difficulty of making such a prediction is confounded by the urban canyon phenomenon as the shock wave intensifies or rarefies depending upon the particular arrangement of buildings. The specific method detailed herein used a Computational Fluid Dynamics solver, ANSYS AUTODYN, to operate on Geographic Information Systems data, ArcGIS, which captured the geospatial relationship between the various buildings in downtown Oklahoma City, prior to the Murrah Building bombing. The model of Oklahoma City was first developed using the building footprints and elevations provided by the ArcGIS database. Due to the sheer size of the problem, the model was then subdivided into annular zones of increasing distance from the center of the blast. Each subsection was then solved using an Euler model in a cascading fashion with the output of the preceding model forming the input of the present model. To further reduce computational time, the size of the Euler nodes was increased at each stage as the section area increased. Due to the loss of precision in capturing peak pressure values when using larger size nodes, it was necessary to perform a transformation on the results using one dimensional wedge calculations with higher precision. The Murrah Building bombing event was an excellent case study due to its available ArcGIS data and the level of documentation of damage to surrounding structures due to the blast. The results from the staged CFD calculation were then used to develop a damage potential contour map. The documented incidents of damage in the area surrounding the Murrah building were then compared to the model generated damage potential contour map. Copyright ©

Jan 1, 2010

By Luis Huaroc, Jorge Cardenas, José Salvador

One of the current challenges in mining is managing increasingly competent rock conditions within the mine-to-plant value chain, particularly when working with marginal ore grades. This study presents a case from a Peruvian open-pit operation where the mine plan projected a significant increase in rock hardness, as measured by the Axb index (parameters derived from the JK drop weight test). In response, the Drill and Blast Technical Team made efforts to increase the powder factor by reducing drill spacing and increasing the explosive charge, employing high-energy explosives (3,090 kJ/kg). However, this adjustment presented a challenge in achieving the fragmentation required to meet the target throughput of 97,500 tons/day, resulting in a shortfall of approximately 8.7% under the base case scenario. To overcome this technical challenge, the use of locally engineered ultra high-energy explosives was proposed, offering adjustable energy levels ranging from 3,210 to 3,570 kJ/kg. This solution enhanced ore blending strategies, calibrated to specific Axb ranges. The results also suggest that microfractures generated by the energetic blasting designs contributed significantly to downstream improvements. These outcomes demonstrate the value of a fully integrated mine-to-plant strategy, aligning blasting parameters with downstream processing performance to maximize operational efficiency. This solution led to a 10% increase in process plant efficiency, a 16% reduction in specific energy consumption during primary crushing, and a 13% reduction in the SAG mill. Additionally, shovel productivity rose by 18%, and the dig rate improved by up to 35%. Keywords: fragmentation, blending, high-energy explosive, power factor, microfractures, specific energy consumption and Axb model.

Jan 26, 2026

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 Santiago Gómez, Pablo Segarra, José A. Sanchidrián

In-hole detonation pressure measurements are unusual in the production environment of a mining operation, partly owing to the hostile conditions to which recording equipment and pertinent probes must be subjected and, partly by the constraints of the production cycle. In recent decades, detonation pressure measurement techniques have been developed using low carbon resistors (LCR)-based gauges. They are cheap, relatively easy-to-operate, robust and with a high percentage of success in both open-pit and underground mining. Detonation pressure measurements are extremely important when carrying out numerical modelling to simulate explosive induced vibrations, since simulation results are highly dependent on the pressure-time history applied on the blasthole wall. Analytical equations have typically been used to model the pressure-time history; however, they usually do not adequately represent the behaviour of the explosive in terms of: peak pressure reached, rise time, mean frequency, decay and shape of the signal. Experimental records may be directly used instead of utilizing synthetic signals if they are available. In this work, (LCR)-based gauges are used to measure detonation pressure inside a production blasthole. The operation principle of the gauges utilized and the instrumentation layout is described in detail. A flexible resolution USB oscilloscope with high sampling rate has been used to catch the elusive pressure peak event. Measurements were carried out in production blasts fired with ANFO (0.86 g/cm3) in an underground mine––this also includes velocity of detonation (VOD) records––. A procedure based on the shock impedance matching has been developed to calculate the detonation pressure due to the characteristics of the gauges prevent its direct measurement. Detonation pressures obtained range from 1.71 to 2.97 GPa (248.01 to 430.76 ksi) which are in line with pressures calculated from the VOD records. Mean frequency and rise time analysis shows that 2 of 3 signals cannot be described using typical analytical equations.

Feb 6, 2023

By Norman Paley

A blasting project was undertaken at the Teck Alaska Red Dog Mine to determine the extent that Semi-Autogenous Grinding (SAG) mill throughput could be increased by using electronic detonators. The Julius Kruttschnitt Mineral Research Centre (JKMRC) blast fragmentation, jaw crusher, and SAG mill breakage models were used to relate changes in the blast fragmentation measured with the SPLIT image analysis system to the SAG mill performance. For optimum performance a SAG mill requires a particular size distribution; a number of large rocks to facilitate breakage by impact, as few as possible middle size rocks that become critical size, and the maximum fines which will pass quickly through an open-circuit mill. Physical constraints of drill and charging equipment size limit the extent that pattern geometry can be changed, and the powder factor increased, to maximize fines. However, a growing number of studies have shown that the use of electronic detonators can lead to increased fragmentation and greater muckpile uniformity, providing an alternate means of increasing primary breakage by blasting. Unfortunately results in the literature rarely quantified the changes to the fragmentation distribution. The measured gyratory crusher fragmentation of 2,750,000t of ore was used to compare stockpiles constructed from shots using pyrotechnic detonators to those using Orica i-kon electronic detonators. In the first stage of the study, stockpiles shot using 25 ms inter-hole timing with pyrotechnic detonators were compared to stockpiles shot using the same inter-hole timing with electronic detonators. In the second stage of the study, stockpiles shot using 17 ms inter-hole timing with pyrotechnic detonators were compared to stockpiles shot using 8 ms inter-hole timing with electronic detonators. When electronic detonators were used with the inter-hole timing kept constant, fragmentation uniformity was slightly increased, but mean fragment size increased by 20%. When electronic detonators were used with faster inter-hole timing, fragmentation uniformity was slightly reduced, but mean fragment size decreased by 30%. Modeling was used to determine the SAG mill throughput which could be expected from this change in fragmentation to determine the pairs of pyrotechnic and electronic blast pattern geometries that would provide similar throughput. The economic benefit from the electronic detonator shots was calculated to assist in determining the optimum blast designs for their use.

Jan 1, 2010

By THOMAS BAMFORD, Dale S. Preece, Amir Behbahanian, Mick Lownds

An important aspect of blasting is rock movement and final muck configuration. Computer modeling of this process has been done in 2D for many years, revealing insights into the blasting process and enabling some design optimization. Since blasting is inherently a 3D process, 2D modeling misses the 3D aspects of blasting results and can lead to inaccurate conclusions. Software development environments in many fields are evolving in 3D, enabled by steadily increasing computer speed, memory, and software efficiency. These same environments are also available for modeling of many physical processes, including rock blasting. This paper documents the development of 3D blast movement modeling techniques that utilize 3D computational mechanics and modern computing environments to predict explosive induced movement of hundreds of thousands of distinct cubic elements representing the rock mass. Blast induced ore travel and final location can now be predicted with reasonable accuracy and acceptable run times. The importance of Energy Partitioning was documented and demonstrated by GEM-2D (Geologic Element Motion) at the ISEE conference in 2024. This software is titled GEM-3D and includes this Energy Partitioning capability. This paper documents a GEM-3D example of ore movement during rock blasting and demonstrates ore dilution as well as the final location of different rock types as influenced by the blast.

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