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By Agus Sasmito, Akash Adhikari, Srivatsan Jayaraman Sridharan, Purushotham Tukkaraja

Previous studies on blast fumes(CO + NO2) clearance and workplace re-entry time have overlooked the effects of toxic gases entrapped in the muckpile. The currently available models forcalculatingthe mine re-entry times assume that all post-blast fumes are emitted upon detonation. However,recentstudies reportedthat as much as 60% to 70% of the fumes or gases produced during an underground development blasting couldremain entrapped in the adjacent rock mass or in the muckpile. Entrapped fumes are slowly released,and when disturbed, high concentrations are released, representing a possible risk during the digging and transportation of the muckpile. This study uses CFD, SC-Flow software to understandthe behaviorof the entrapped fumes and theireffect on mine re-entry time.

Feb 1, 2020

By Bjoern R. Petterson, Lars Haakon Siem

The world's longest highway-tunnel -- the Aurland Tunnel in western Norway -- is scheduled to be opened in the year 2000. A project to build a main highway between Oslo and Bergen with no ferry connections was approved by the Norwegian Parliament in January 1995. Construction of the five-year blasting project was started by the Norwegian Highway Authority in mid-March 1995, with an expected completion date of November-December 1999.

Jan 1, 1996

By John Wright

As part of the redevelopment of the Royal Brisbane Hospital complex in Australia, a number of antiquated buildings were to be demolished and replaced by newer, modem facilities. Aside from the decommissioning of the hospital buildings, the project called for the removal of approximateIy 24,000 bank cubic metres (bcm) of varying quality rock material. Given the sensitivity of the project, in particular the close proximity of the required excavation to the existing hospital structures (-3 metres at the closest point), and the requirement that these were to remain lily operational during the construction phase, it was initially proposed to use hydraulic rock hammers as the primary means of excavation. Poor production rates and unexpected dif3icuIt rock conditions led to a revision of the excavation methods and a feasibility study on drill and blast practices was undertaken. Subsequent to an initial series of trial blasts to illustrate that vibration and flyrock could be adequately controlled, drill and blast methods were used in conjunction with mechanical methods of rock breakage. This paper reviews the drU and blast processes and the practices which were necessary to comply with the multiple constraints imposed on the project. The project has highlighted that modified drill and blast practices remain a cost-effective method of excavation, even in sensitive areas which are commonly deemed inappropriate for such methods.

Jan 1, 2000

By Manuel Gutierrez, Roberto Gomez, Juan Aravena, Johan Gjoevad

The use of explosives in mining operations is a process that involves the search for an ideal explosive for the type of geological condition of the mineral to be extracted. For the explosives present on the market the majority are based on Ammonium Nitrate. This as it is an ideal balance of high energy efficiency achieved with low development of gas emission. The manufacturing and loading operation of the explosive requires multiple process stages and different raw materials, which, if is not correctly supervised and controlled may cause the development of harmful gases or, in the worst case, even toxic gases. The majority of mining operations are located at remote locations without the presence of communities, and hence individuals, which could be affected by emission of the harmful or even toxic gases. In these operations the protection is mainly to protect the employees of the operation. However, if the operation is located near communities, the effect of these gases becomes a serious problem. The communities' perception of post-blasting gases, according to interviews carried out in this project, describes these as smells of black gunpowder, damp soil with a volatile permanence and medium intensity, sometimes a stinking tone is added. The legislation in Chile that controls the exposure of “workers” to different gases is Supreme Decree 594, 2019 (Decreto Supremo 594). Currently the Chilean Ministry of Environment and Sernageomin (Servicio Nacional de Geología y Minería) are taking actions to reform and strengthen oversight, seeking through a short law to provide more tools to the government to decentralize decisions in case of non-compliance with the decree. This paper describes the development and implementation of a permanent and remote gas monitoring system, considering the reasons for choosing the gases to be included in the equipment, the types of sensors and their capabilities, the way to verify in the field the correct functioning of the technology throughout the project, and finally how the data collected in the field is meeting the government's expectations in terms of permanent and online reportability. Additionally, it addresses the continuity of gas monitoring in the community that will disappear in the short term due to the expansion of mining operations, thereby ensuring the protection of both workers and affected communities.

Jan 21, 2025

By Galetakis M., Deligiorgis B., Xiroudakis G.

Fragmentation prediction is important in surface mining to optimize downstream processes such as loading, hauling, comminution, and beneficiation processes. Traditional approaches, such as the Kuz-Ram model, image-based fragmentation analysis, and numerical simulations, rely heavily on large datasets acquired after blasting. Moreover, due to the inherent limitations in each method there is an underestimation of fine and coarse fragment sizes, when applying these models without prior knowledge regarding the fragmentation distribution. These drawbacks are restricting their use only in post-blast parameter prediction. In response to these inefficiencies, this study presents a deterministic fragmentation prediction methodology based on a single-blasthole model. The model simulates the formation of the damage zones around a blast hole based on the number of cracks within a distance from the centre of the blast-hole and correlates them with an estimated fragment size in each domain. A fragmentation distribution from the literature is employed to validate the proposed approach and the results are compared with those generated using a modified Kuznetsov model. This approach aims to enhance blast design decisions by enabling pre-blast fragmentation prediction. Based on this, blast designs could be estimated depending on the desired fragmentation before blasting, giving the opportunity for a tailored to local rock properties optimization.

Jan 26, 2026

By Roland Alford

The ballistic pendulum is a well-established piece of test equipment originally developed for estimating the velocity of bullets and projectiles. When trying to understand the effects of different tamping methods on explosive performance, the ballistic pendulum is an excellent tool allowing calculation of explosive charge impulse. Most ballistic pendula for this application are limited to narrow impulse ranges as the pendulum mass determines the angle of swing; and a mass capable of being moved by a small charge would be far too small for a larger charge. This paper describes a modular design (the Alford Modular Ballistic Pendulum) which overcomes this problem.

Feb 6, 2023

By S. Gajardo, E. Valdés Guerra

Together with Sociedad Punta del Cobre S.A. (Pucobre) and Orica, we are carrying out a study of alternatives for methodology of excavation in Slot Up Raises from actually built with Blind Hole (BH) to drilling and blasting (DB) methodology. The study is part of the permanent search for innovation, the use of technology and the reduction of mine operation costs. This application aims to optimize the Sub Level Stoping method, which has historically been exploited at Pucobre. Using a new variant of the method “Open Stoping”, through the initial development of ascending blind raises using a pilot drilling of a bore hole, with the objective of eliminating the upper level in order to excavate the free face opening. This industrial test aims to replace the mechanized BH Up Raise of 1.5m (4.9 ft.) in diameter and 30m (98.4 ft.) high, with a Up Slot Raise considering two separate blasting events, using different technological enablers, as detailed below: accuracy drilling with relief holes of 254mm (10 in.) diameter, high viscosity bulk emulsion, wireless initiation system and high-strength injectable bulk resin. Considering the importance of the success of this application, a DB diagram was defined to allow the opening of the up raise in two blasting events, separated by intermediate stemming deck located at the same level at a height of 15m (49.2 ft.) from the collar, using high-strength injectable resin. The first blasting event considers the first section from the collar to the first 15m (49.2 ft.), using wired electronic initiation that is detonated on the first day. A second event blasts the section from 16.5 to 30m (54.1 to 98.4 ft.), using a wireless initiation system, as, it has no physical connection, is blasted on the second day after the extraction of the material resulting from the first event. For greater precision, the design of the explosive charge configuration and initiation sequence is made, adjusted to the measurements of trajectory deviations of the actual ground drilling and is also considered for the control of the explosive charge configuration with high viscosity bulk emulsion. This application improves the profitability of the mining business by generating savings through the change of Blind Hole methodology, estimating a savings of more than 75% per Up Slot Raise

Jan 1, 2024

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 Natalie Zeleznik, Brian Hawkins, David Bradley, Rachel Gooding, Patrick Wilson

"An Event Tree Analysis (ETA) is an established approach for logically deconstructing and assessing scenarios for probabilistic risk assessment. This deconstruction into a series of understandable eventsfacilitates probability estimation for explicitly defined explosive terrorism scenarios with consideration of modes of possible failure during execution (a scenario is defined through selection of a target, selection of an explosive material, and interdiction prior to arriving at general target location, etc.). Further, each event is decomposed into a range of possible outcomes. The physical action or reality ofthe outcome is statistically represented by “branches” of the event tree (e.g., the terrorist may choose totarget a stadium, hotel, or subway; terrorists may be successful or unsuccessful in acquiring the material)."

Jan 1, 2017

By William Reisz

Managing the blast site at almost any operation can be a daunting task. There are so many details that must be observed, understood, and acted upon. It goes without saying that there are no two locations that have the exact same challenges and concerns. The level and the extent of these challenges can vary widely.

Jan 1, 2014

By Jhon Silva

"Signature Hole and Waveform Superposition techniques used to predict and control mine blast ground vibrations require a clearly defined information collection configuration. The collection of this information determines the scope and success of the ground vibration prediction. Application of the Improved Signature Hole technique using the Silva-Lusk equation requires the collection of at least two informational elements from any specific production shot. The first required element is a signature waveform, and the second element is the overall production blast waveform. The signature waveform depends on detonated charge variables such as the amount of explosive in use, use of decking, the possible detonation of several holes at the same delay, and many others. The production blast waveform is beneficial to the Improved Signature Hole methodology when used to calibrate the model, and toobtain accurate vibration predictions for different timing configurations."

Jan 1, 2017

By Mark S. Stagg, David E. Siskind, Stephen V. Crun, Willard E. Pierce

The USBM is studying the impacts of low-frequency blast vibrations on residences to assess both response and cracking potential. Complementing coal mining sites monitored in the midwest and east, vibrations were analyzed at a major construction site in southern Florida where potentially serious low-frequency blast vibrations were believed to exist.

Jan 1, 1996

By David E. Siskind

"This report describes recommended vibration monitoring and assessment practices at blasting sites.Intended is regular monitoring, tracking of trends, responding to complaints of alleged damage, and the technical and data aspects of addressing lawsuits."

Jan 1, 1999

By Harry Verakis, Thomas Lobb

Widespread use of ammonium nitrate compositions for mine blasting operations has led to various bulk transport vehicles designed especially for the explosives industry over the past half century or more. The advancements in explosives technology and continuing developments in bulk transportation have resulted in a variety of blasting agents and, more recently, oxidizers being transported and used from specially designed bulk transport vehicles. It is estimated that about 2000 bulk transport vehicles are used in mining operations. Many of the bulk vehicles carry about 15,000 to 33,000 pounds (6808 to 14,968 kilograms) of payload and some can carry up to 50,000 pounds (22,679 kilograms) for large open cast mines. Thus, it is imperative that detailed knowledge and safety instructions are available from the blasting personnel and mine management should an unplanned incident such as a fire occur with a bulk transport vehicle at a mine site.

Jan 1, 2008

By Jim Petrunyak, Conny Postpack

The authors describe in this paper a systematic approach toward reducing coal production costs up to 35% through the use of explosives energy for overburden removal. In this system, explosives are employed to blast as much as 65% of the overburden instantly from highwall to spoil pile, with only the lesser portion requiring removal by dragline, shovel, or loader.

Jan 1, 1983

By Ali Kahriman, D. Adiguzel, R. Ulger, U. Akkaya

The environmental problems arising from ground vibration has been faced and discussed frequently in various industries such as quarry, mining, civil works, shaft, tunneling, pipe line and dam construction etc. where the blasting operations are unavoidable. This paper presents the results of ground vibration analysis induced by blasting during the construction of the Istanbul Kadiköy-Kartal metro tunnel. Different rock formations in this tunnel route which is 21.6 km in length were encountered during the excavation process by blasting. As a first stage, Hoek’s Geological Strength Index (GSI) values of rock units were determined by using inverse distance weighting method. The GSI values which were obtained from boring data were used when evaluate the data. GSI values were estimated by inverse distance method (figure 3) along with the tunnel route. Afterwards, ground vibration parameters induced by 21 shots which were made in different locations was monitored and passing routes of vibration waves determined. Weighted averages of GSI values were calculated according to distance of the regions where vibration waves passed. Multi regression analyze were made with using frequency, charge per delay, GSI and the distance between the shot point and monitor station. The main goal of this study is to investigate the relationship between ground vibration frequency induced by blasting and GSI.

Jan 1, 2011

By Patrick D. McLaughlin, C Fordham

"The project outlined in the accompanying paper was to densify beach sands on the pond side ofa tailings dyke to the strength required for future dyke construction, This was to be achievedthrough the detonation of relatively small explosive charges in the sand to cause settlement intoa denser state."

Jan 1, 1992

By Gregory B. Poole

Data collected with 16K sampling at a variety of blasting sites (construction, quarry, trench, mine) and monitoring locations was analyzed to effectively show the 16 different 1K readings all based on the microsecond that the unit went into monitoring.

Feb 1, 2020

By Rob Lederer, Chris Batten

Traditionally coal model digital terrain models (DTM) are created from lithological information obtained from broad scale exploration holes. The grid layout and distance between holes means that models do not commonly display local variations of seam dip, faulting and shearing. Due to this, issues can often arise when designing the loading of blast patterns based on potential variances between model and actual coal seam locations. Many sites will often attempt to create more accurate models through the collection of data from coal edge pickups on highwalls and in blast faces, along with information recorded by drillers (touch coal holes) from both production and presplit holes for both the current and previous blasts.

Jan 1, 2012

By Nikolaos Petropoulos, Ulf Nyberg, Daniel Johansson

A series of signature boreholes were blasted to observe any difference between confined and free face blasts. Four geophones were used to capture the compressive wave. The conventional approach, i.e. the calculation of vectorized peak particle velocity (vPPV) did not show any difference. Also a wavelet transform was tested.

Feb 1, 2020