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By Thomas M. Keevin, Gregory L. Hempen

"Natural resource agencies, under various regulatory authorities, are challenged with permitting underwater explosive use while at the same time protecting aquatic resources. Deciding on whether or not to allow use of explosives requires striking a balance between development and aquatic resource protection. A company’s goal in underwater explosive use is to select methods that are both expedient and cost effective. The use of explosives is often the best alternative for engineering reasons or economic considerations. Over and above legal requirements, indiscriminate destructionof fish and other aquatic resources is not in a company’s best interests because of concerns relatingto public image, as well as the need to secure future contracts."

Jan 1, 1995

By Vasile Pop, Ovidiu Galca, Constantin Salajan

The paper comprises a brief presentation of the rock fracturing techniques applied in CNMPN “REMIN” Company’s mines in Baia Mare. Parallel are emphasized some shortcomings of this field. The second part of the paper includes our preoccupations and achievements, of the last period, in especially those linked to techno-economical indices improvement resulting from the development of relatively large section mining works and blasting applied with sublevel caving methods.

Jan 1, 2003

By Sam Ammermann, William Heasley

"The mining industry is on an ever accelerating path to complete mechanization. As companiesutilize more sophisticated and efficient methods of blasting, a more thorough look should begiven to the pros and cons of mechanized shaft sinking. Historically, Vertical Shaft SinkingMachines (VSSM) have been capital intensive, making it hard to enter lowest bidder marketssuch as the United States. As advances in safety and technology have occurred, VSSM methodsare becoming increasingly common in many countries outside the United States. Decreasedcapital requirements, a greater amount of competition within the VSSM market along withgreatly improved safety practices, have made it more competitive with traditional drill and blast(D&B) methods. However, VSSM technology has yet to be embraced by the United States. Alarge culture shift will have to occur before VSSM technology will become common in theUnited States. The history, and advent, of raised boring machines will be discussed and how itrelates to the current development of VSSM technology. The researchers will analyze the uniquerisks of D&B methods and how they compare with the unique risks of VSSM technology. Theresearchers will put an emphasis on risks directly affecting the safety of personnel working onthe shaft sinking operation. Many of these risks are identified by contracting companies withregards to geology, relative location of resources and the chosen shaft sinking method. Theresearchers will discuss specific risks a given shaft sinking company will want to consider whenchoosing between D&B and VSSM methods."

Jan 1, 2016

By Eduardo Lozano, Vilem Petr

This paper provides an overview of a new method for avalanche control using a high explosive charge placed at the avalanche runout zone: the case charge technique. This new avalanche control technique is well-suited to mountain roads presenting several advantages over the existing methods: minimum deployment time, low cost, reduced probability of misfires, and decreased operation time in the avalanche danger zone. The research work presented in this paper was conducted via large scale laboratory experiments where the detonation velocity and the blast physical properties were measured. During the charge design, several parameters were controlled: charge mass, diameter, geometry, density, and external confinement. In addition, the effective range of case charges was increased by the use of the Mach reflection for certain topographical situations. Finally, field test results collected by the Colorado Department of Transportation (CDOT) during the 2017 winter season are presented. The CDOT avalanche control crews have adopted the new case charge as the preferred technique in numerous avalanche locations along the Rocky Mountains roads.

Jan 1, 2018

By Daniel Mallette, Richard Goodridge, C M. Lownds

Despite a world of mobile devices that has many of us taking the ability to communicate wirelessly for granted, an in-hole wireless initiation system was thought to be not viable. The known and common wireless communication techniques are not suited to this application. To overcome this, we have developed cutting edge technology to communicate to our initiating devices more than 1km through solid rock.

Jan 1, 2016

By M. Ganster, H. Krenn

The mission of the project is the fast and cost-effective rehabilitation of decommissioned lignite mining and coal upgrading facilities. This is necessary to ensure the successful future utilization of these sites. On the one hand, for founding new industrial and commercial facilities and on the other hand for touristic activities.

Jan 1, 2013

By Charolett Hayes, A. L. Russell, Anthony J. Bednar, Jared Smith, Valentine A. Nzengung, Stephen L. Pilcher

The manufacture of Energetics Materials (EM), including maintenance and demilitarization of munitions causes dangerously high levels of explosives residues to be harbored in building features. The two commonly approved methods of decontaminating energetics contaminated equipment and building features are thermal treatment and steam washing. The current regulatory environment is generally becoming more stringent and unfavorable to thermal and steam decontamination because of their adverse impact on air, soil, and water and their ineffectiveness to completely remove accumulated energetics from foundation cracks, internal and external piping, voids in walls and ventilation systems, and internal cavities of fixed equipment. However, chemical destruction of energetics, especially high explosives, is gaining acceptance as a safer, cost-effective and environmental friendly alternative to thermal and steam decontamination. Organic explosives, including nitramines and nitrate esters are oxidized organic compounds that are susceptible to chemical oxidation and reduction reactions. Under suitable conditions, a chemical reagent consisting of sulfur-based bulk reductants (neutralent) commercialized as MuniRem generates highly reactive free radicals that very rapidly degrade many energetic compounds to innocuous end products while stabilizing metals as the insoluble metal sulfides.

Jan 1, 2016

By William D. Hissem

For those blasthole applications which require the use of holes ranging from 1” to 5.5” in diameter, the use of top hammer drills has been the equipment of choice for several generations of drillers. Pneumatic compressed air and hydraulic compressed oil systems represent the primary technologies which are available to the drilling practitioner. While both employ the same operating principals, the characteristics of performance, cost, and reliability can be markedly different between technologies and manufacturers.

Jan 1, 1998

By Pierre L. Labelle

Non electric Dual Delay initiators have revolutionized many aspects of underground mining. The units are used in all types of underground blasting operations. Some operations, due to the complexity and variety of their blasts, have extremely large inventories of conventional non electric products. The Dual Delay system has drastically reduced these inventories and has added an important element of versatility to blast designs.

Jan 1, 1994

By P. O'Connell, J. Lever, C. Clemence

The Bulyanhulu Mine, Tanzania is constantly trialing ideas for improvements in the drill and blast process. The project work has resulted in a large number of choices in explosive type and charging methods being available for blast design. Interestingly, though booster sensitive bulk emulsion had been introduced to the site to reduce dilution, better results were being obtained from reduced charge columns (decoupled columns of poured anfo in 50mm pvc pipe) and pneumatically loaded anfo upholes, which had been traced. In order to compare the explosive type and charge up-methods, an explosives comparison trial was performed.

Jan 1, 2006

By Shi Hongchao, Zou Zou Xinkuan, Zhang Jichun

As drilling and blasting is carried out in an urban tunnel, which is adjacent to an existing building or structure, the balance between blasting-induced vibration reduction and drivage efficiency is a most important issue that must be resolved properly. Therefore, a new cut blast method named Stepped V-cut millisecond blasting (SV-cut) was developed by optimizing the most common used Vertical V-cut blasting method (V-cut). The most significant features of SV-cut lie in the utilization of sublevel interval charging structure and millisecond delay blasting technology in cut hole and the cut-cavity formed from outside to inside sequentially. SV-cut provides advantages of high borehole using ratio, low vibration level, and satisfied advance per attack. Based on the principal of millisecond blasting, the rock fragmentation process and the vibration reduction mechanism of SV-cut are analyzed. Determining methods of blasting parameters, which do have significant effect on vibration intensity and cut-cavity formed quality, are proposed according to the forming requirement of both outer and inner cut-cavity and vibration reduction. In order to compare the performance between SV-cut and V-cut, field blasting experiments were performed in the blasting engineering of Yamalike twin-arc tunnel, which closely passes over aged parallel tunnels. Blasting results show that SV-cut blasting is proven as an effective tunnel blasting method for both increasing blasting effects and decreasing blasting vibration. Comparing SV-cut with V-cut, the SV-cut can increase blasting drivage about 8.5% and reduce the vibration intensity induced by cut hole blasting 30% at least.

Jan 1, 2015

By V. A. Akinbinua

This work is intended to examine the relationship between rock fragments produced during compression tests using a soft testing machine, e.g. hydraulic press (the machine used in this work is Amlser rock testing machine), and the rock fragments size distribution produced by fragmentation of the same rock through application of explosive. The rocks tested are fine grained marble, medium grained tonalite and fine-medium grained granite, medium grained norite and medium grained gabbro. The rocks types are prepared according to ISRM methods to be tested for strength determination. The rocks are loaded at constant load until failure. The fragments resulting from the failure of each of the rocks types are collected for size characterization by sieve analysis. The same rocks tested under soft testing machine are also prepared into blocks of dimension 150 mm length x 100 mm width x 100 mm height for blasting by explosive application. Each block of the different rocks are drilled through with an 8 mm diameter drill to a depth of 80 mm. Each of the holes on the blocks is spaced from each other at 44.7 mm and with a burden of 28 mm. The holes therefore formed a rectangular blasting pattern. Each of the holes was charged with a 720 mg electronic detonator and fired instantaneously inside a cylindrical blasting chamber. After each shot, the fragments are collected for size characterization. The sizes distributions from blasting are compared with sizes distributions resulting from rock testing using the parameter Xc of the Rosin-Rammler distribution function (RR) and 75% cumulative percentage passing. The analysis and finding from this work is presented in this paper.

Jan 1, 2014

By Dale S. Preece, Stephen H. Chung

Explosives energy can be used effectively in breaking and displacing large volumes of rock in mining and quarrying industries in both open pit and underground. The blast result, however, may not be economical if the applied explosives energy distribution is not properly applied to match a given set of geometries. However, this engineering problem can be resolved by using a modeling approach in the blast design process. Starting with a given set of blast design parameters that include explosive, elastic properties of rock, geometry of the blast pattern as well as the delay firing time, this paper shows how a discrete element blast model can be set up to allow the examination of the effect of critical design input parameters on blast results. Examples are given in this paper to help visualize the value and application of blast simulations. They are (1) regular and terrace bench blasting models for throw control, (2) underground blasting including a drop raise opening and (3) collapsing of a multiple room-pillar structure with proper firing sequence to control the mixing of blasted materials.

Jan 1, 2005

By Türker Hüdaverdi, Özge Akyildiz

"In this research, image analysis technique, Kuz-Ram and KCO Models were used to examineefficiency of the quarry blasts. Investigations were performed in Cendere region, Istanbul. As a firststep, image analysis software was used to determine particle size distribution of muckpiles.Additionally, the results of KuzRam and KCO fragmentation models were compared to the results ofthe image analysis technique. The efficiency of KuzRam and KCO models was investigated and theimportant points to be considered were explained. Additionally, the effect of the rock factor valueson the size distribution curves was investigated. The blasthole diameter is 89 mm. (3.5 in) in thestudied quarry. Each measured blast has a different burden, spacing and stemming length. Blastholes was drilled in a staggered pattern. It is concluded that, KuzRam and KCO models can be successfully used to determine fragment size distribution in Cendere Region Quarries, Istanbul. Site engineers can predict blast fragmentation using the theoretical fragmentation models and they may change blast design parameters before blasting operation if necessary. It is possible to calibrate the Kuz-Ram and KCO fragmentation models using the measurements obtained by image analysis technique."

Jan 1, 2016

By Dale Preece, Stephen Chung, Qian Liu

Stoping is one of the widely adapted methods in underground mining. In this method, fanned or parallel holes are often drilled from a top sill down to a sub- level in the ore zone and blasted ring by ring into a stope for excavation. At Brunswick Mine of Canada, this technique has been used daily in conducting production blasts. However, when mining into the West Ore Zone, it has been identified strategically that a mass stope blast, involving the blasting of rock from the 3-sub level down to the 1-sub level, should be considered to ensure the safe operation and regaining of access to the trapped main ore zone. The challenge of this mass blast lies in the control of ground vibration and precise timing for blasting 800 holes drilled in six blocks from three different levels within 6.5 seconds, to allow sufficient void to be created in each level for the muck moving in order from the upper to the lower levels without bridging. This paper describes stope blast simulations using a discrete element computer code for modeling blast-induced rock displacement in conjunction with a precision electronic programmable delay timing system for various stope geometries including a drop raise blast at the start of the mass blast. The modeling concept is also described in the paper.

Jan 1, 2003

By E. McCullough, D. Preece, M. Ortel

Geophysical explosive charges are used in mineral resource exploration. They are detonated subsurface and radiate sonic waves into ground monitors, which detect the vibration waves and their interaction with underlying geologic strata. Geophysicists perform computer analyses of the waves reflected from the strata to determine their depth and thickness (Strobel, Berger & Schaefer, 2012). The purpose of this research is to determine how the detonating explosive charge interacts with the adjacent ground and how the induced waves propagate through the surrounding medium. Furthermore, it is necessary to optimize the location of the initiation point within the charge. Establishing both the direction and intensity of the waves will allow geoscientists to refine and optimize geophysical studies that employ explosive charges.

Jan 1, 2013

By George P. Jr Schivley

Looking at the process of drilling rock from the standpoint of the power required, yields an equation that relates Force-on-the-Bit; Torque, to rotate the bit; and bit Angular Speed to the Penetration Rate of the bit; the Area of the hole being drilled and the Specific Fracture Energy of the rock. Specific Fracture Energy and the Compressive Strength of the rock are related.

Jan 1, 1994

By Jarrod Bonsmann

"This paper presents the results of small scale testing to examine the effect of various importantparameters on the response of a vehicle due to the detonation of an explosive charge buried inthe soil below the vehicle. In particular, we were interested in examining what effect change instandoff distance, change in mass, and change in surface area would have on the loading applied.We examined the impulse delivered to the target in all cases and for the change in mass andchange in stand-off distance we examined impulse, kinetic energy, and acceleration."

Jan 1, 2012

By David Harrison, Edward J. Walter, Meitra Ferek

Agreat tool in the prevention of blasting complaints and subsequent damage claims. In today’s highly competitive industry, we are always looking for ways to become more cost effective. This article investigates the importance of pre-blast surveys-not just for regulatory compliance, but as an overall long term cost cutting and public relations tool.

Jan 1, 1995

By Wayne A. Charlie

An experimental test program being conducted at Colorado State University and involves the study of the behavior of water saturated sands under shock and explosive loadings. The study is being conducted to evaluate potential blast induced changes in dynamic soil properties, soil shear strength loss (liquefaction) and densification of water saturated sands under single and multishock loadings. This paper presents testing and measurement objectives, and the equipment and instrumentation developed to load, measure, record and analyze the transient and long term soil behavior. The laboratory shock facility is capable of generating multi-shock pulses with milli-second rise time, peak stress amplitudes of up to 35,000 KPa (5000 psi), peak particle velocity of 5000 cm/set and peak acceleration of 10,000 g. The field explosive facility subjects saturated soil to controlled explosive loadings. Of major interest is the soil strain and water pressure, both during and after the passage of the stress wave, as a function of peak particle velocity, peak strain, loading rate, soil density, initial confining stress and the number of loadings. Based on data obtained to date, soil densification is due to consolidation following liquefaction.

Jan 1, 1991