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By Matheson and Miller

Does anyone have any definitive information on vibration limits for damage to well casings near blasting? Also, are people using self-imposed limits when approaching cased wells? I can only tell you what I have personally done with success. Often in new construction in hard rock, the well is drilled before the foundation is excavated and before the ditch for the water line is excavated. These both require drilling and blasting. Under these circumstances when blasting for the ditch for the waterline we will drill right up to within 10 inches (not feet) of the well casing. We drill line holes the width of the ditch, then about a foot from this, another row of trim holes then as we move away from the casing holes for 1 1/4 inch stick powder for about three rows then as we get further still, we can load with ANFO. I do not have vibration data for this but my experience has been that as long as you are not displacing the material into the casing that no damage is done. These typically are steel casings for residential water service.

Jan 1, 2010

By Robert B. Hopler

Reefs, exposed rocks, and fast currents made the Hell Gate section of New York's East River a treacherous passage ever since man attempted to sail through the area. As the harbor's importance grew, attempts to improve the channel were made, starting in 1851. This paper discusses the first major organized effort to clear the area, which began in 1869 and culminated in a single large blast in September 1876.

Jan 1, 1981

By Benoît Pinier, Jason Furtney, Gustavo Sampaio Lopes, Jorge Valencia, Johan Hawinkel

This paper describes a numerical modeling study on the effect of airdecking on vibrations, fragmentation, and movement in mining-related rock blasting. Practice has shown that air gaps reduce blast vibrations and damage while maintaining the required fragmentation and movement, yielding similar blast outcomes with less explosive mass per hole. Given that the premise of “replacing explosives with air” for better blast results is counterintuitive, this paper aims to shed light on the physical mechanisms and processes occurring in a blast with airdecks. It is hypothesized that airdecks are effective and beneficial because they load the rock at pressures lower than what is required to crush the rock. In the airdeck, the explosive gasses directly fracture rock and avoid energy loss due to crushing. In essence, the airgap allows similar outcomes in fragmentation and throw with less total explosive product, as the lower pressure gasses in the airdeck are still effective at breaking and moving the rock. This is distinct from only having less explosive and more stemming, as the stemming reduces the pressure more than an airdeck at the same position. This study uses the blastFoam software (for modeling of single and multiphase flows) to accurately calculate the pressure history throughout a blasthole and air gap. The pressure and gas loading are coupled to numerical models of vibration, fragmentation, and blast movement. Using this modeling technique, a suite of blast scenarios for typical configurations in a range of commodities is assessed with and without airdecks. Rock blasting practitioners have a responsibility to protect communities, infrastructure, and heritage — demystifying airdecks through a better understanding of the physics provides another tool in the blasting engineering toolkit to serve this goal.

Jan 21, 2025

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 Rolf Schillinger

Transport of Small Quantities of Explosives Material on Public Roads The transport of dangerous goods on public roads is extensively regulated by EU and national law. The transport of explosive material is not only done by forwarders but also by small companies and private persons with the goal of their own use. The following article tries to explain what is allowed and what is not.

Jan 1, 2010

By Raden Haris Handayana, Jerri Mapanta, Eri Barlian, Milia Putri, Nasfryzal Carlo, Jihan Lubis

Waste oil is a growing problem throughout industries where environmentally responsible disposal ways are usually costly. There are many industries have developed process to reuse of waste oil as a source of energy on their own premises. Hanwha Mining Services Indonesia is one of blasting service that manufacturing explosive using waste oil. The usage of 60 % waste oil content in fuel solution already developed applied since 2020 at Petrosea-Kideco Site and will be increase until 100 % in 2022. The purpose of this research is to analyze the increasing of waste oil usage from 60 % to 100 % content at Petrosea Pit without reducing the emulsion quality and performance, and surely eliminate the fuel cost and reducing waste oil processing cost. Some trial conducted to determine the effect and quality of using 100 % waste oil content on emulsion at production blast. The method use to know the quality of 100% waste oil of emulsion is by direct application on bench blast. Using Microtrap VoD recorder, explosive energy will be recorded into m/s dimension, microtrap recorder the speed of explosive detonation in line with the speed of burning wire in the blast holes. The summarized of this research present that the using of 100 % waste oil content on emulsion can be applied on bench operation with the result of Velocity of Detonation (VoD) data is 4,559 mm/s, the mean of fragmentation size is in range 65.31 to 225.62 mm, the average of digging time on 1st layer is in range 10.2 to 11.6 s and on 2nd layer is in range 8.9 to 9.5 s, and the productivity still achieve on target. The result of all parameter quality still in the standard range of Hanwha and Petrosea.

Feb 6, 2023

By Raden Haris Handayana, Jihan Farhan Lubis, Milia Putri, Tengku Deli Hamonangan Hasibuan, Sani Salahudin

An environmental issue that must be controlled from coal overburden blasting near the structure is ground vibration. Damaging ground vibration is the effect exerted from residual energy from blasting that does not work to fracture the rocks. Sebuku Tanjung Coal is a coal mining that operates T3 Pit adjacent to the High Voltage Tower. This structure is included in the Class 5 building with a maximum Peak Particle Velocity (PPV) of 40 mm/s. The shortest distance from the blasting location to the structure is 105 m. The initiation system used is electronic detonators combinate with emulsion as an explosives type. In Indonesia, the government regulated vibration limitation on SNI 7571:2010. The blast outcomes targeted are PPV below 40 mm/s, fragmentation size <80 cm for Excavator Komatsu PC-2000, and digging time <12 seconds. In this paper, the blast design was engineered by conducting Signature Hole Analysis for optimizing delay timing configuration and Scale Distance regression analysis to determine optimum charge weight per delay at the blast site. PPV results from 30 blastings achieved 100% below 40 mm/s with the range of about 1.773-30.250 mm/s. The deviation between PPV prediction to PPV actual is less than ±18% which provides the blasting with electronic detonator resulting in good PPV prediction for controlling vibration. The average fragmentation size (D80) is 55.81 cm in the 1st layer and 54.81 cm in the 2nd layer. The average digging time is 10.30 seconds in the 1st layer and 10.12 seconds in the 2nd layer.

Feb 6, 2023

By Rodney Pinksen, Remi Proulx

The IOC Mining and Operations Departments expressed an interest in reducing the amount of oversize material (>1.0 m x 1.0 m x 1.0 m; 39 inches x 39 inches x 39 inches) being produced and its subsequent downstream effects including in-pit sorting and reduction, damage to mobile equipment, and significant delays in the loading pockets and the primary crushers. To achieve this goal an oversize reduction project was undertaken by the mine and to date has significantly improved upon baseline measures.

Jan 1, 2011

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 J. P. Remi Proulx, Areli Rodriguez, Ruilin Yang

Historically, presplitting has been considered effective in reducing the impact of blast vibrations on highwalls. However, it remains a debated topic: how significantly can it protect highwalls, and is it worth the cost and effort to implement presplit blasting techniques? In hard rock, presplit blasting can leave half-barrels on the highwalls, clearly demonstrating its usefulness. However, in a fractured rock mass, the half-barrels from presplit blasting may not appear in most cases, leading to questions about its role in protecting highwalls. Previous studies in the literature used geophones to measure blast vibrations at far distances and could not ascertain the significant benefit of presplit blasting in reducing the impact of blast vibrations on highwalls. Additionally, no studies in the literature address the role of presplitting in alleviating blasting-released gas pressure that could penetrate joints and open new fractures in highwalls. Yang & Proulx (2019) and Yang et al. (2022) using near-field blast vibration monitoring of signature hole blasts have revealed that the peak particle velocity (PPV) of blast vibrations at a scaled distance of 1 m/kg^0.5 can be reduced by 50% or more for presplit-filtered vibrations. These results have been confirmed for both hard rock and fractured ground. In addition to summarizing the reduction in blast vibrations due to presplitting for both hard rock and a fractured rock mass, this paper demonstrates the relief of subsequent blasting gases after the detonation of blastholes. This is shown through video recordings of gas ejections from a row of empty previously fired presplit blastholes located 6 to 9 meters away from the detonation edge or final buffer row of a blasthole pattern. The results clearly show that presplitting not only lowers blast vibration PPV’s but also reduces the entry of the gases produced by the detonation process into rock fractures and or open joints.

Jan 21, 2025

By Joshua Calnan, Braden Lusk, Kyle Perry

This paper presents detailed information and data regarding the load transfer characteristics of Blast Resistant Glazing Systems utilizing two different thicknesses of polycarbonate. A series of triaxial load cells, along with surrogates of identical stiffness characteristics, were placed around the glazing perimeter to directly measure the load transferred to the support system from explosions of varying degrees. The blast loads were developed using an explosive driven shock tube administered by the University of Kentucky Explosives Research Team (UKERT) in Georgetown, KY. Results presented include distribution of loading, maximum load transferred to connections, blast pressure-time data, glazing system deflection-time data, and final performance results of each system. The two glazing systems respond differently to the applied blast loading. Differences and similarities in the load transfer characteristics are discussed. The experimental results are then compared to a commonly used blast resistant glazing system analysis software tool utilizing a Single Degree of Freedom (SDOF) method of analysis for each system. Preliminary results show that currently used models do not correspond well with experimental data.

Jan 1, 2014

By Alan Diaz Butron, Eng. Thierry Bernard

"In tunnel blasting the most challenging objective is definitively obtaining the maximum advanceassociated to a minimum overbreak. Achieving 100% of advance with no overbreak is the targetchallenge by Chavimochic Consortium. Chavimochic Special Project is an irrigation system that extends throughout much of the coast of the La Libertad Region, on the north coast of Peru. In 2012, it began management for construction of the third and last stage of CHAVIMOCHIC to irrigate lands of Chicama Valley, North of Trujillo. This project of 13 Km (8 mi) of various tunnels, it's a combination of technology and daily optimization by experienced people, which allow to accomplish the objective. Achieving this advance with no overbreak provide a huge saving on time. This paper describes the method, technology used, and the results obtained on more than 600 blasts done with conventional initiation system on the first 3 km (1.86 mi)."

Jan 1, 2017

By John Manka

Emulsion explosives consist of an aqueous oxidizer phase, a fuel phase, and an emulsifier. The ability to use lower-cost sources for any of these raw materials presents an obvious economic advantage to emulsion manufacturers. This paper focuses on using low cost waste drain oils as the fuel phase in emulsion explosive applications. Laboratory studies showed that emulsions made from waste drain oils and agricultural ammonium nitrate prills were usable for emulsion explosives though their shear stability was weak. Customer field results proved that waste crankcase drain oil could replace half of the virgin diesel fuel in emulsion explosives to make an effective emulsion explosive product with a very low cost.

Jan 1, 2003

By R W. Thomas

This paper explores the possibilities of generating radical improvements in the drilling costs and productivity of blastholes through the efforts of integrated teams as opposed to traditional customer/vendor relationships.

Jan 1, 1996

By Sandy Tavelli, Thomas L. Barkley

This discussion will present a case study in developing solutions to a metropolitan quarry’s public relations, legal, environmental, and productivity problems. It details an extensive and detailed project to address the blasting practice in a medium sized quarry that is surrounded by residential and industrial zones. The principle work was done over a four-month duration during the normal production season. It included detailed drilling and blasting audits for baseline information. In addition, geologic characterization, seismic modeling, correction of deviations from best practices, and implementation and monitoring of precise electronic timing to provide dramatic solutions for the quarry. The quarry is in the near suburbs of a large metropolitan city. It is framed on two sides by residential municipalities and on two sides by industrial zones. At the start of the project, the quarry was in court as a result of the lawsuit by one of the neighboring towns that was suing to close the quarry. The lawsuit had progressed to the advanced stage where in the Judge had appointed an arbitrator to make the decision of continued operation. This arbitrator was to observe our progress and recommend to the Judge the disposition of the case.

Jan 1, 2004

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 Christopher Jon Preston, Troy Williams, Daniel Roy

There has been significant progress made with narrow vein gold mines in which a second option for crushing has begun to attract attention. To ensure the profitability of a mine that has based its economics on the absence of a crusher station, more than just best blasting practices are required. Using a blasting operation itself as a primary crusher would undoubtedly save enormous capital costs as well as eliminate some of the costs of crushing ore with the result that considerable savings might be realized. The challenge would be to define the conditions necessary to make this type of operation feasible by providing consistent blasting methods that result in a significant paradigm shift with respect to both blasting and current underground crushing methods. A break model has been developed and applied as a technique in designing blasting patterns based on a unit charge blasting geometry and stress reflection from free faces. There are four components to this model and these are 1) unit charge, 2) thermodynamic/energy, 3) stress reflection, and 4) radial break. Some important changes in timing between holes and rows based on rock properties and the percentage of burden moved were also used. On-site testing at a narrow vein gold mine in Quebec Canada, provided measured parameters for the model. No underground crusher was planned - relying only on the fragmentation profile generated by ring blasting. The specification for muck was that the fragmentation profile needed to be 100% < 400 mm (16 in) with no overbreak - with dilution less

Jan 1, 2019

By Mark Svinkin

To save time for construction of coal pits, the contractor decided to combine erection of the tower pitheads with digging of skip shafts to the depth necessary for placing proper coal pit equipment. It was obvious that blasts used in shaft faces and lifting machines installed at a lower part of the pithead could excite vibrations of an upper part of the pithead with curing concrete. The contractor was concerned about vibrations of pithead concrete structures and the disturbance of freshly poured concrete in forms at a top of the pithead as a consequence of structure vibrations. The results of a study of the tower pithead structure vibrations from blasting and operating machinery, and effects of structural vibrations on curing concrete are presented. Structural vibrations were measured at the tower pitheads of two coal pits from twelve blasts. Records of horizontal and vertical displacements were superposition of harmonic low-frequency damped vibrations and sporadic high-frequency damped vibrations with a variable frequency. Low frequency vibrations attenuated during 8-13 s after the last delayed blast. Measured values of the natural frequencies of pithead horizontal vibrations coincided with the calculated frequencies of horizontal bend vibrations. An increase of a face depth from 18 to 50 m diminished 16 times horizontal bending vibration displacements of concrete structures. Measurements of vertical structural vibrations from blasting demonstrated increasing of vertical pithead displacements with the rising of structure elevations. This is evidence of the pithead longitudinal tension. The holes with charges were not properly condensed for one blast. As a result of incompact stemming, the blast substantially increased the energy of airborne pressure waves, which triggered natural vertical vibrations of the pithead with high displacements.

Jan 1, 2004

By Vitor Barcelos, Eduardo Elói, Gabriella Vaz, Davi Oliveira, Leandro Silveira

Following a routine production blast at Vale S.A.'s Itabira Mine in the Quadrilátero Ferrífero region of Minas Gerais, Brazil, nearby residents registered complaints about blast-induced vibrations. Analysis of the blast footage revealed that multiple blastholes were detonated simultaneously, resulting in a higher-than-expected charge per delay, ground vibration and cratering even though the electronic delay timing was configured correctly. Subsequent blasts within the mine's soft schist region confirmed the occurrence of sympathetic detonation. Mitigating or eliminating this phenomenon is critical for the mine's operation. Two dynamic pressure tests were conducted using carbon resistors together with typical VOD monitor maintaining the standard booster, electronic detonator, and a blend of 70% emulsion with 30% ammonium nitrate explosive. The tests involved increasing the distance between the central hole (detonated first) and the four surrounding holes in a five-hole sequence. Unfortunately, sympathetic detonation occurred in all these tests. To address this issue, a new explosive with a lower density and detonation velocity was tested. This approach proved promising, as no sympathetic detonation occurred. By leveraging the data obtained from this study, engineers can now identify situations at risk of sympathetic detonation and implement preventive measures, such as selecting the appropriate explosive and recommending safe minimum burden and spacing settings as well as confinement level for each blast while maintaining the desired level of rock fragmentation.

Jan 21, 2025

By Dennis Wilzbacher, John Wiegand

In an effort to reduce the cost of bulk explosives, Vigo Coal Company found that the addition of coal mined at their Friendsville Mine, not only reduced explosive costs, but also appeared to actually enhance blasting performance. The Friendsville Coal lies at the base of the Mattoon geologic formation within the Mcleansboro Group of the Missourian Series of the Pennsylvanian Geologic System in Southern Illinois. Vigo Coal Company commissioned VIBRONICS, INC., an independent blasting consulting company to quantify actual blasting performance. Insitu sonic velocity testing of overburden was conducted to determine the P-wave velocity of the sandstone present at Vigo’s Cypress Creek Mine, where the initial testing was conducted. Numerous VOD (velocity of detonation) recordings were obtained for varying blends of ANFO/Coal (now named Carbo*Prill). Cast blast percentages were determined for both Carbo*Prill and non coal blended bulk explosive blasts. The VOD of the coal blended product was intentionally reduced so as to more closely match the P-wave velocity of the sandstone overburden. Explosive blends containing as much as 40-50 percent coal were tested. Explosive blends containing greater than 30 percent coal, have been used in Cypress Creek Mine overburden production blasts. The coal blends appear to produce better fragmentation and yield excellent cast blast performance. Safer mining conditions were also observed. Flyrock potential was reduced. The blasts produced less back break, producing a safer highwall. Stripping dozer and shovel production rose during the testing period and equipment repair costs were lowered due to an increase in overburden fragmentation. Blasting vibrations were reduced, in part due to the lowered detonation velocity of the ANFO/Coal mixture. The Friendsville Coal Seam appears to contain inherent chemical and physical properties that enhance blasting performance. The use of Carbo*Prill has been approved by MSHA, BATF, the State of Illinois, and the State of Indiana. This paper will provide details concerning testing procedures, blast performance analysis, recommendations and conclusions for using this alternative blasting mixture.

Jan 1, 2007