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By Tom Short

"Construction blasting covers a very extensive variety of explosive applications. I will discussseveral of these with you and then show slides from my collection, starting in 1956, which will betterillustrate the types of blasting under discussion."

Jan 1, 1991

By Ricardo Dr. Chavez, Mathieu Lachamp, Rob Dr. Farnfield

Pueblo Viejo is an open pit gold mine in the Dominican Republic which is always looking forward to implement the newest technology in the industry to improve all processes. Focusing on one of the pillars of the department and our company, digitalization, we’ve been looking for the technologies that allow us the automation of data generation, supervision and process innovation. That’s where a new Drill and Blast software takes place, helping to integrate the process from the beginning to end, right after the pattern is designed until it’s blasted, allowing us to track results like vibration, fragmentation, performance, cost and inventory of each blast in a single platform. The software helps engineers to generate back analysis by blast, bench, pit, month and many other ways, in a timely friendly manner. Therefore, we can catch business opportunities and improvement for the drilling and blasting process.

Jan 1, 2019

By Randal Martin

Recently, questions regarding the influence of atmospheric temperature and humidity levels on airblast levels have arisen at a number of blast sites. Humidity is alleged to have contributed to high levels of disturbance within communities surrounding blasting. In some cases, local regulatory agencies considered adopting guidelines to specify humidity and temperature ranges under which blasting cannot take place. However, it is normal blasting industry practice not to consider humidity or temperature effects, in the absence of inversions, on airblast levels. When blasting is conducted in the vicinity of residential structures, the influence of weather on the propagation and attenuation of airborne noise from the blasting site is always a concern. Sound naturally attenuates in air with distance from the source. A part of this attenuation is attributed to divergence at the airblast wave front, while the remainder of the attenuation is an accumulation of various factors that include temperature and barometric pressure, absorption in air due precipitation and vegetation, wind and temperature gradients, atmospheric turbulence and topography (Beranek, 1971). Wind speed and wind direction, as well as vertical and horizontal temperature gradients can cause airblasts to focus in local regions surrounding blasting operations and may result in air pressures greater than expected. In fact, wind and temperature inversions can actually increase sound levels with distance from the blast site. Close to the blast site, the effects of inversions may be negligible but may exceed 10 dB at 800 m or greater (Davis and Cornwell, 1991).

Jan 1, 2001

By N. Skopak, C. Aimone-Martin, J. Redyke, B. O. Meins

PipeBlast is a spreadsheet-based calculator based on research conducted by Southwest Research Institute (SwRI), used by the pipeline industry to determine if proposed blasting planned near existing pipelines can be safely executed. The two factors determining “safe” are blast-induced pipe wall hoop stresses and predicted peak particle velocity (PPV) at the pipeline. Although methodology used to predict hoop stresses is somewhat sound, predicted PPV amplitudes are highly exaggerated based on inappropriate attenuation models developed using spherical explosive charges of limited charge weights, placed in soil adjacent to model pipelines that do not represent rock blasting. Hence, pipeline companies readily reject well-design blasts and limit scaled distances far beyond what is reasonable and cost-effective to pipeline owners. Full-scale trench blasting in rock was conducted near a 24in (711mm) diameter operating API 5L X70 grade steel pipeline in Texas to compare PipeBlast model predictions with a Ground Strain Model (GSM) based on field measurements of ground motions on the surface and at the pipeline springline. Results of the GSM were compared with pipeline strains measured using wire gauges mounted on the Springline. The comparative results showed that a site-specific velocity propagation model provided good estimates of ground strains that are replicated on the pipeline walls in terms of hoop and longitudinal strains. Trench blasting 28ft (8.5m) from the pipeline produced ground motions of 7.6in/s (193mm/s). At this ground motion amplitude, the factor of safety defined as the allowable stress divided by the combined operating and blasting hoop stresses was reduce from 3.04 in the absence of blasting to 2.98. This paper explains the research and findings on which PipeBlast is based and presents an alternative approach to predicting blast-induced pipe wall stresses based on site-specific velocity propagation measurements and a ground strain model.

Jan 1, 2024

By Abigail Styer, Paul Holmgren, Josh Calnan

Detonating cord is a staple of the explosives industry, used widely in the civil and defense industries. Detonating cord is a thin, flexible plastic tube filled with pentaerythritol tetranitrate (PETN). It has many applications in mining, construction and military disciplines. For civil applications, it is used to connect and initiate a series of blastholes in a desired pattern. In the defense sector, it can be used as a detonating agent, a priming agent or alone as an explosive charge. Research has been done to understand the initiation and detonation physics on the detonating cord. However, its sympathetic detonation characteristics needed to be further analyzed. The sympathetic detonation of the detonating cord can lead to the poor performance of production shots in mining or civil applications and unsafe conditions in defense applications. This paper focuses on the analysis of different factors involved in the sympathetic detonation of various sizes (grain weights) of detonating cord. The variables analyzed include the minimum distance between segments of detonating cord and grain weights. These variables were analyzed by securing segments of detonating cord at measured distances apart on a steel plate and detonating them. The physical examination of the aftermath of this detonation included a qualitative recording of data. Applications of detonating cord that could be affected by this research include mining and construction blast initiation, explosives disposal, and breaching.

By David Ziegler

A formal blast plan is sometimes required for projects involving rock excavation. A written blast plan submitted with a bid proposal can also be an important sales tool. A blast plan will cover the basic elements of shot design: hole diameter, spacing, burden, loading, and so forth. Some suggestions are discussed here for additional items or topics to address, including: safety issues, ground control, traffic & site control, public relations, pre-blast inspections, seismic monitoring.

Jan 1, 2003

By Gregory Poole

With access to the World Wide Web, many resources are readily available for improving claim reports. With a little time spent on line, a more thorough report can be created. Claimants will accept the conclusions of a report more readily when they can view support information on their own computer, particularly when the support information is not just from blasting related web sites. Some suggested resources are discussed including aerial pictures, local tax maps, topographical maps and home repair web sites. This paper provides suggestions for tracking down support information on the web and information on how to properly reference this information. Case studies of several claim investigations are presented. These are some examples of how a little time spent online provided clear and convincing evidence to support the conclusions of the investigation.

Jan 1, 2006

By Enver Alan

This Research & Development (R&D) study was conducted in the field of applied blasting engineering in Ethiopia, within the AKH Railway Project, which was built in Girena, within the boundaries of the province of Mersa, in the Basalt Quarry at km 346, Ashangi Formation, occured in Eocene geological time in the aphanitic trachibasalt. Under the scope of the study, which has been performed to determine the effects of the artificial discontinuities at different depths and the effects of artificial discontinuities through structural damage risk, three test areas, at the same location and same formation, were considered. Six numbers of artificial discontinuities, each 10 m (32, 81 ft) transverse, were created by using pre-splitting and drilling-blasting technology. The number of sequential artificial discontinuities on each test area is two and they have the same length. The length of artificial discontinuities are; 6,80 m (22,31 ft) at the first test area, 13,60 m (44,62 ft) at the second test area and 17,00 m (55,77 ft) at the third test area respectively. The distance between sequential artificial discontinuities is 8 m (26,25ft) on each test area. Thirty-one shots were executed in order to produce vibration (10 shots on the first test area, 11 shots on the second area, 10 shots on the third test area). One hundred and twenty-three seismic recordings were obtained during the execution of the shots by using 4 seismographs. The closest distance between the shot points and the nearest measuring station is 5,30 m (17,39 ft). During the shots, the rock was cracked and there was no fragmentation and/or fly rock. At the first test area, measured PPV values are between 25,40-127,00 mm/s (1-5 inch/s) before the first artificial discontinuity and less than 50,80 mm/s (2 inch/s) after the second artificial discontinuity. At the second test area, measured PPV values are between 76,20-177,80 mm/s (3-7 inch/s) before the first artificial discontinuity and less than 76,20 mm/s (3 inch/s) after the second artificial discontinuity. At the third test area, measured PPV values are between 50,80-279,40 mm/s (2-11 inch/s) before the first artificial discontinuity and less than 50,80 mm/s (2 inch/s) after the second artificial discontinuity. Peak reduction rates in Peak Particle Velocity (PPV) values determined by measuring as follows: In the first test area 95,77% (106,00 mm/s to 4,48 mm/s) (4,17 in/s to 0,18 in/s), in the second test area 79,77% (176,00 mm/s to 35,60 mm/s) (6,93 in/s to 1,40 in/s), in the third test area 95,85% (from 205,00 mm/s to 8,55 mm/s) (from 8,07 in/s to 0,34 in/s). The arithmetic mean of the differences of PPV values (decrease rate) is 82,66% in the first test area, 69,37% in the second test area, and 92,03% in the third test area. The highest sound value is 138,50 dB and is defined as “noise”. When the measured parameter values are examined it was determined on the USBM norm graphs that these vibrations carry a risk of structural damage in the region before the first artificial discontinuity. While passing through artificial discontinuities the vibrations progress by losing energy and the vibrations passing through two artificial discontinuities do not carry structural damage risk under current conditions.

By Robert Hivick, Frank Sames

The control of environmental effects, especially blast vibration and airblast, has become a dominating planning criterion for most surface blasting operations. Compliance with existing regulations is generally achieved through constraints in the blast design, or monitoring programs. Commonly, blast vibration and airblast signals are rated and compared by their maximum amplitude and the associated principal frequency. However, this data reduction limits the interpretation of the influence of varying blast design parameters on the vibration and airblast.

Jan 1, 1999

By D. Swanson

Cold Detonation Physics (CDP) is a patented new field of explosives and the name for the explosive that is produced when non-toxic dry ice (frozen carbon dioxide) is combined with powdered metals such as magnesium and aluminum, which are non-toxic and nitrogen-free. The explosive is detonator-sensitive and detonates according to the rapid reduction of carbon dioxide back to carbon, which produces solids comprised mainly of metal oxides and about 5% carbon. CDP was determined to produce a maximum of 300 liters of carbon dioxide per kilogram (4.81 ft3 /lb) and about 1.5 liters of carbon monoxide per kilogram (0.024 ft3 /lb). Both these figures shift according to metal content where higher metal produces less gases. According to theoretical modelling, the relationship between static pressure and metal content was determined to be an inverse parabolic curve with optimum pressure at 25% to 31% metal, depending on the type/s of metal/s used. Velocity of Detonation (VOD) was determined by measuring light at the wavefront with fiber-optic cable inserted into a series of holes drilled into the side of a 3-inch diameter (76 mm) schedule 40 steel pipe containing the mixture. The highest VOD was observed at 25% magnesium and measured between 2,500 to 4,500 m/s (8202 to 14,764 ft/s) when initiated by a 454-gram (1-pound) booster and an electric detonator. A 25% 50:50 alloy of magnesium and aluminum sample shot at a higher velocity than magnesium, according to how the alloy generated smaller pieces of shrapnel when compared with shrapnel from a magnesium test. CDP, using 25% alloy, was tested for blasting limestone by drilling 3.5-inch holes (89 mm) and inserting a 3-inch x 4-foot cardboard tube (76 mm x 1.22 m) with the mixture, packed to a density of 0.62 g/cm3 . The blast was initiated with an electric detonator, behaved like ANFO with more energy and fractured rock sufficiently across the entire length of the borehole. Seismic analysis determined that CDP produces lower ground vibrations than traditional explosives.

Jan 1, 2024

By Constanza Bujes, Mark Jones, Graham Crook, Yansan Jamyanbaatar, Sedat Esen

Tracking ore characteristics such as grade and hardness from its original position into the material handling and processing stages remains one of the key challenges in open pit mining of hard rock deposits. The most efficient technique for rock fragmentation and separation of ore from waste is blasting, which induces changes in the grade distribution by displacing the in-situ ore into a diggable muck pile. Material movement defines the post-blast grade distribution, which is key to optimising the value of the ore and accounting for ore loss and dilution. Techniques to directly measure the displacement in open pit mining have been implemented routinely and have provided calibration and validation data for blast models to build upon. The JK Value-Based Ore Control blast movement model (JKVBOC) is the latest development of a series of research studies into blast movement and ore control at the Sustainable Minerals Institute of the University of Queensland. The blast model discretises the bench into blocks, defines the initial velocity of each block based on the blast design, confinement and explosive properties, and simulates the displacement using a physics engine. Calibration and validation of the model has been performed in open pit hard rock mines in Australasia in diverse confinement conditions. This paper describes the calibration and validation of the blast movement model against direct measurements of blast movement and final muck pile shape for a case study where the displacement of multiple shots was modelled for an open pit mine, with an analysis of the implications for ore loss and dilution. A key finding in this study is the need for further integration of this technology into the existing systems for ore control, and the potential for applications in tracking ore characteristics other than grade into process control.

By Mark A. Williams

"This paper was originally intended to be a presentation of a case study of two surface bituminouscoal mines in the southern Appalachian coal fields located within five miles of each other. These mines were nearly identical in every aspect from geologic setting to equipment application. Althoughrepresentatives from each mine desired to participate in the preparation of this paper through support in providing background information and in review and editing, it was later concluded that, due to the environmental sensitivity associated with each mine, it may not have been a good decision to present this case study in a public forum."

Jan 1, 1994

By Jorge Cardenas, David Martinez

Blasting-induced vibrations can be predicted with high precision, allowing for the optimization of sequence design, delay timing, and charge configurations to minimize their indirect impact on rock masses. This optimization leads to a reduction in peak particle velocity (PPV) and dominant frequency at monitoring points. However, a crucial aspect of slope safety is estimating the degree to which vibrations influence stability through numerical modeling of the dynamic response. Slope stability is closely linked to rock mass strength, the predominant failure mechanism based on discontinuity orientation relative to the slope face, and the pre-existing stability conditions before dynamic alterations occur. Blocks, wedges, and planar failures tend to slide under lower vibration levels and are more susceptible to resonance, particularly in fractured and low-strength rock masses. To evaluate the interaction between rock mass and vibrations, photogrammetry and artificial intelligence were employed to identify discontinuity families at vibration monitoring sites. This data facilitated the development of artificial discontinuity networks (DFN), which replicated a discontinuous medium within a numerical finite element model. The input signal was recorded at the slope base using triaxial geophones and incorporated into a discontinuous numerical model. The output signal was estimated through finite element analysis and subsequently compared with geophone measurements taken at the same location. Based on real-world output signals, damping parameters and the model’s natural frequency were adjusted to align both frequency spectra. Using the calibrated parameters, vibration records from various blasting projects at different distances were applied as input signals until slope failure was induced, thereby defining maximum allowable vibration limits in terms of PPV and frequency at the monitoring point. This approach provided a framework for optimizing sequence designs, charge configurations, and delay timings to enhance slope safety and prevent failure due to blasting-induced vibrations.

Jan 26, 2026

By Alexandre Passos, Giorgio De Tomi, Tatiane Marin, Dennis Cremonese, Jacopo Seccatore

"In the mining industry, rock excavation is the first phase of the comminution process. Downstreamoperations such as secondary breaking, crushing and milling terminate the process, reducing the size of the grains down to the desired particle distribution. In such a cascade process, every process upstream heavily influences all the downstream operations. When rock excavation is carried out by drilling and blasting, a very economic source of energy (the explosive) is used at the utmost upstream; a more expensive source of energy (electricity) is employed for all the downstream phases. This means that managing the correct employ of the explosive energy is a form of managing the whole process, controlling the operational costs and therefore the profitability of the whole business. We simulated this cascade behavior, using as a starting point the experimental data obtained from small-scale block blasting, evaluating the influence of blasting on the grindability of the blasted material. This study showed the reduction in visible (particle size) and invisible fracturing (micro-cracking, resulting in a reduction of the Work Index WI). The particle size distribution for full-scale blasts was estimated by means of algorithm simulation, then we simulated the behavior of the comminution plant fed with the material possessing the characteristics previously estimated. All the costs (drilling, blasting, electric energy for the engines of the crushers and mill) were calculated and charted. The results show a clear curve that allows to estimate the minimum operating expenditure (OPEX) for the whole mine+plant framework. Being the WI dependent on the output on the blast, one can manage the performance and the expenditure of the whole comminution process by adjusting drilling and blasting parameters For any given mine, it is possible to perform a simulation and encounter the minimum OPEX scenario for the comminution process and managerial choices can be oriented accordingly. In a cascade productive chain as mining is, responsible strategic choices must be taken looking at the entire production framework. Compartmentalized managerial staff and budgets for separated production areas are not acceptable anymore. Somehow higher costs upstream can lead to effective decrease in costs and increase in efficiency and productivity of the processes downstream."

Jan 1, 2016

By Ali Kahriman, Alper Celtikc, Serdar Celik, Tuncer Gungor

This paper presents the results of ground vibration measurements carried out in Gülyali Hisarcik Basalt open pit mine located on the north side of the Anatolia near Ordu province in Turkey. Within the scope of this study in order to predict peak particle velocity level for this site, ground vibration components were measured for 5 shots during bench blasting. In blasting operations; ANFO (blasting agent), gelatin dynamite (priming) and delay electric detonators (firing) were used as explosives. Parameters of scaled distance (charge quantity per delay and the distance between the source and the station) were recorded carefully and the ground vibration components were measured for all blast events using 5 different vibration monitors (4 White Mini-Seis and 1 Instantel Minimate Plus Models). The absolute distances between shot points and monitor stations were determined using GPS. The equation of square root scaled distance extensively used in the literature was taken into consideration for the prediction of peak particle velocity.

Jan 1, 2013

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 Benedicto Hadad Cintra

In an inflationary environment the need for reduced cost is a daily concern of all industries. The Du Pont do Brasil "Expanded Pattern" method has proven to be an extremely effective means of reducing costs in mining, quarrying and construction operations. Over the past years much emphasis was placed on rectangular drilling patterns where the burdens are less than the spacing. The Expanded Pattern method combining rectangular and staggered patterns, was implemented in 1971 in Brazil after extensive trials in close collaboration with numerous explosives users and Du Pont do Brasil Technical Services Engineers. The best multiple row spacing-to-burden ratio (S/B) was demonstrated to be in the 2 to 5 range and the effective spacing to burden ratio (Se/Be) was found to vary from 5 to 11. These ratios are for the interior of the blast pattern and do not hold true along the front row of holes. Geological rock properties, hole diameter and inclination, explosives energy and loading density, explosives characteristics, blast pattern geometry, bench height and delay patterns along with type and size of digging, hauling and crushing equipment must all be evaluated for each and every operation. The integration of these interrelated parameters, together with sound blasting practices are the basis for the Expanded Pattern method. Color slides and documented case histories will be presented.

Jan 1, 1985

By Roberto Folchi, Hans Wallin, Mara Battocchio

An understanding of explosives science and technology, and the competence to harness it is central to maintaining Explosives capability, national security, and in sustaining a competitive industry. A consequence of eroding this competence is the increased likelihood of explosives accidents. These are often catastrophic as demonstrated by accidents in Nigeria, Russia, Toulouse and Enschede. In addition to the serious loss of life there was the very significant damage to houses, domestic and industrial infrastructure and to the environment at a cost of many millions of Euros.

Jan 1, 2013

By Toby Forney, Joshua Schoonover

In typical surface quarry operations, productivity and efficiency related to pit development begin with drilling and blasting efforts. By embedding technology within drilling and blasting operations, blast results can be tailored to benefit the quarry by driving continuous improvement of production. This technical paper will focus on the continuous improvement efforts at a cement limestone quarry in Maryland and how those efforts have impacted mining production, safety, and efficiency with the application of specific blasting technologies.

Feb 6, 2023

By Patrice Favreau, R. F. Ph. D. Professor Emeritus Favreau

After Nobel invented dynamite, blasts were carried out by trial and error, without the use of equations based on the fundamental principles of Chemistry and Physics, although everyone accepted that shock waves were involved; but no equations were available to calculate their intensity. Around 1950 however, M.A. Cook proposed a procedure to calculate the thermochemistry of an explosive, and thus evaluate theenergy released during the explosion of a fully confined explosive. Some blasters then began to use theEnergy Factor; the latter, however, does not subdivide the energy into its three kinds of activities necessaryfor a successful blast, as demonstrated in 1968 by reference 2, namely i) the shock wave which weakensthe rock; ii) the stress field SS which fully fragments the rock; and iii) the release of the stress SS whichcauses the fully fragmented rock to burst out with the velocity necessary to move the rock into the muckpile. The article explains that the way to achieve a successful blast is by insuring that the explosive energy divides properly into the weakening action of the shock wave which is necessary to prevent large collar blocks and toe, and into adequate stress field intensity SS which is necessary to obtain good fragmentation size distribution at the crusher, as well as adequate burst out rock movement to achieve easy mucking.