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By David Harrison

The Charleroi Locks and Dam (Figure 1) was completed in 1932 and is located on the Monongahela River, approximately 22 miles (35 km) south of Pittsburgh, in Charleroi, Pennsylvania. It is comprised of a 420 foot (128 m) gated dam, and a 720 foot (219 m) by 56 foot (17 m) land side lock which provides for a 16.6 foot (5 m) vertical lift.

Jan 1, 2015

By Rolf Koenig

After the Dynatronic firing system was demonstrated for the first time at the SEE conference in Miami in 1987, it was officially approved in Germany at the beginning of 1993. Dynatronic has now been on the market for 5 years. At present, it is used in several European countries and successful test series have been running in Australia.

Jan 1, 1998

By Ruilin Yang

This paper provides a theoretical analysis of shockwaves in an air-deck induced by detonation of an explosive charge and shows that the initial shock pressure in the air-deck at the interface with the explosive charge is only about 1% of the detonation pressure. A rarefaction wave with the low pressure travels back into the explosion detonation products greatly reducing the post-CJ detonation pressure. Additionally, AUTODYN modelling shows that the pressure attenuates further during shockwave propagation along the air-deck. Although the pressure increases at the bottom of the blasthole due to shock reflection, the overall pressure in an air-deck does not increase and is still around 1% of the detonation pressure which is too low to break most rock.

Jan 1, 2016

By David Harrison, Brian Harrison

The Army Corps of Engineers completed the Charleroi Lock and Dam in 1932. It is located on the Monongahela river approximately 22 miles (35k) south of Pittsburgh in Charleroi, Pennsylvania. It is comprised of a 420-foot (128m) gated dam, and a 720-foot (219m) by 56-foot (17m) land side lock, which provides for a 16.6 foot (5m) vertical lift.

Jan 1, 2018

By Paul Worsey, Seokbin Lim

In many high explosive applications, the explosives are covered or clad by a metal. This metal cover may serve a variety of purposes including: 1) to protect and prevent the disturbing or misshaping of the explosive during its transportation, handling and use, 2) in many military applications the cover material itself is used to provide a required effect, for example, the shrapnel from grenades, the metallic liner of shaped charges, and the confinement of explosives so they perform optimally, and, 3) in civilian applications in the use of well perforating shaped charges and linear shaped charges used for the demolition of steel structures such as bridges. For these reasons the interactions between the explosives and their covering materials are of great importance in understanding the performance of these devices.

Jan 1, 2005

By Jhon Silva-Castro, Russell Lamont

Understanding the behavior of materials subjected to high strain rate conditions is of fundamental importance to the mining industry. Several stages of the mining process involve high speed loading rates including blasting, scraping, comminution, etc. Technical comprehension of how rocks deform, fracture, and fail under these loads is a fundamental first step required prior to any serious attempts at optimization of the energy utilized for pertinent activities in the mining process. A Split-Hopkinson Pressure Bar (SHPB) was designed and constructed at the University of Kentucky to study the dynamic properties of various types of rocks.

Jan 1, 2017

By John W. Kopp, David E. Siskind

Over 4 billion pounds of commercial explosives are used by the U.S. mining industry every year with an excellent and improving safety record. However, accidents involving explosives are seldom minor. They produce a disproportionate amount of fatalities compared to other mining activities, as reflected in the relatively high severity rates. The U.S. Bureau of Mines (USBM) has been analyzing blasting accident data obtained from the Mine Safety and Health Administration (MSHA) to determine the most frequent causes of mine blasting accidents, examining trends in these accidents, and identifying areas of needed research. This paper is an update of three previous blasting accident studies conducted on 4-year intervals by the USBM and published in 1983, 1987, and 1991, and is based on a total of 869 blasting accidents.

Jan 1, 1995

By Kamal Wadhwa

Liquid oxygen explosives have been used in India for well over 5 decades now. These are being extensively used both for shallow and deep hole blasting in the various opencast mines and quarries for mining of coal, limestone, ironore, bauxite, magnesite etc. IOL Ltd., are the pioneers in the introduction of these explosives in India and are marketing these under the brand name 'LOXITE'.

Jan 1, 1991

By P Wapner, C Lo Edwards, S CO Schmidt, J N. Johnson, R Oliver

Shale oil recovery rates that can be achieved in underground in situ retorts can be strongly influenced by the shale breakage and fragment-size distribution achieved during rubblization. Since the fragmentation pattern in the retort is a direct result of the blast design used for rubblization, the characterizing blast parameters should be carefully selected. Explosives should be matched to the host material and blast geometries properly chosen so that the required fragmentation results are achieved at optimum costs. Special attention must be directed to selecting blast parameters that produce uniform bed permeability, suppression of fines, proper fragment size distribution, and minimal damage to the retort walls and ceiling. The influence of joints and natural fractures should also be known. In instances where the requisite blasting parameters are unknown, they should be determined from test blasts.

Jan 1, 1979

By Y Nagendra, A. Ravi Kumar

A breakwater is a construction for protecting the marine structures like port, harbor, or anchorage-basin and berthed marine vessels from the destructive influence of the sea waves. The breakwater is constructed by using geologically competent, heavy, massive rock like granite, basalt etc having physical and mechanical properties within the limits specified by the designers. The construction requires boulders in varying sizes ranging from 0.5 kg to 20,000 kg. The stones from 0.5 to 1000 kg are called as core fill and boulders greater than 1000 kg are termed as armor blocks. These armor blocks cover and protect the core fill and prevent it from escaping. The requirement of armor blocks ranges between 25 to 35 %. The rest is core fill. However, the actual requirement depends on the breakwater design. In this context, the task of the mining engineer is to economically produce armor blocks and core from the designated quarry in right proportion with minimal losses. The whole bunch of engineering ingenuities should be put forth for obtaining the required armor blocks. The armor block production from any blast depends chiefly on geological conditions, bench dimensions and blast design. This paper is an attempt to bring out the various parameters affecting the performance of the blasting for armor block production using a case study.

Jan 1, 2005

By Richard J. Mainiero, Eric S. Weiss

This project investigates the behavior of blast waves from the detonation of high explosives in an underground mine. A series of explosive tests was conducted in the underground and surface facilities at the Bureau of Mines' Lake Lynn Laboratory to evaluate the potentially dangerous effects of blast waves produced by open shooting, blown out holes, or accidental detonations of explosives. Shots of C4 and TNT were fired at the dead end of a 6 ft high by 20ft wide entry, at the intersection of two entries, and on the surface. C4 and TNT were chosen for this research because they exhibit very consistent performance. Behavior of the blast wave was evaluated through recording of the pressure as a function of distance from the explosive detonation.

Jan 1, 1995

By Robert Hopler

Accidents associated with the storage of explosives prompted regulating the locations of such storage at least as early as 1719, when an act was passed in Great Britain. During the following years various refinements to the regulations were made, but a major explosion in 1864 in which there was destruction and loss of life as far away as 10 miles, led to the landmark Explosives Act of 1875. This act certainly had influence on regulators in the United States: when Massachusetts established an explosives distance/weight table in 1904 they referred to the prior British work. Later, Colonel Dunn of The American Railway Association convened a conference of explosives manufacturers to discuss safe storage. From this conference the American Table of Distances was established in December, 1910.

Jan 1, 2007

By Tom Hale

Developers and blasters are faced with increasing public demand and regulatory restrictions to maintain the lowest possible levels of noise and vibration from blasting operations in populated urban areas. Pyrotechnic products have proven to be a low noise, low vibration alternative to conventional blasting for close-in rock excavation and concrete demolition applications. Pyrotechnic breaking charges often yield 1/10th the vibration and noise compared to traditional explosives, and have been demonstrated to increase public confidence and decreased damage potential where they have replaced explosives, thus allowing new opportunities for work and greater job profitability. This paper presents a practical approach to utilizing pyrotechnic products in various applications including trenching, mass excavation, demolition, and dimension stone production, providing methodology for pattern design, vibration probability and loading calculations. Field research data is reviewed and compared to conventional explosives.

Jan 1, 2008

By Gungor Tuncer, Ali Kahriman, A. Kadir Karadogan, Savas Gorgun

The environmental problems arisen from ground vibration and air blast have been faced and discussed frequently in various industries such as mining, construction, quarry, pipe line etc. where blasting is unavoidable operation. Structural damage due to ground vibrations creates great socio-economic problems for mine and quarry management as well as for the people residing in its vicinity, therefore in bench blast design, not only the technical and economical aspects, such as block size, uniformity and cost, but also the elimination of environmental problems resulting from ground vibration and air blast should be taken into consideration. With the general trend towards larger blasts in mining and infrastructure excavation, ground vibration and air blast problems and complaints have significantly increased. With increasing environmental constraints on the levels of disturbance induced by blasting operations upon nearby residents, there is an increasing need to be able to design cautious blasting with greater precision, therefore determination of maximum amount of explosive per delay for a certain distance especially in large blasts is of great importance for the elimination of these environmental problems. In another word, prediction of ground vibration components is extremely important for the minimisation of the environmental complaints. Estimating of particle velocity and other components of ground vibration with reliable approaches will give important facilities to the blasters. Although many studies had been carried out to isolate environmental problems induced by blasting in the past, a general reliable formulae has not been established yet. Due to restrictions on the complexity of ground motion, blasting and test site factors, experimental studies are still necessary for each site to minimise environmental issues. This paper presents the results of ground vibration measurements carried out during the excavation activity for contruction of an organised industrial region located nearby Istanbul in Turkey. The major rock type is granite that is encountered at this site. Within the scope of this study, in order to predict peak particle velocity level and produce a site-specific propagation curve for this site, ground vibration components were measured for blast events during bench blast optimization studies over a long period. In blasting operations; ANFO (blasting agent), gelatine dynamite (priming) and delay detonators (firing) were used as explosives. While the parameters of scaled distance (charge quantity per delay and the distance between the shot and the station) were recorded carefully, the ground vibration components were measured by means of two different vibration monitors for every event. Then, the data pairs of scaled distance and particle velocity were analyzed. The equation of scaled distance extensively used in the literature was taken into consideration for the prediction of peak particle velocity. At the end of statical analysis and evaluations an empirical relationship with good correlation was established between peak particle velocity and scale distance for this site.

Jan 1, 2000

By David Yanez

The hydroelectric project "El Cajón" is currently under construction in the state of Nayarit, on the Santiago River, in western Mexico. This project is comprised of a Concrete Face Rockfill Dam (CFRD) with a rockfill necessity of 10,5 million cubic meters and it reaches a height of 188 m. The generation equipment includes two turbines with a total installed capacity of 750 MW.

Jan 1, 2006

By LaRay Collyer

San Juan Mine began pre-splitting the highwall prior to cast blasting in August 1986. The first pre-split shot used six inch PVC (polyvinylcloride) pipe inside a 10 5/8 inch hole, drilled at a 74 degree angle. The powder factor was about .90 pounds per cubic yard.

Jan 1, 1990

By P Albert

A wedge-shaped underwater rock plug has to be blasted in order to tap the reservoir and furnish water to a new underground powerhouse at Manicouagan-5. The paper deals with the design and engineering aspects of drilling and blasting of this plug where the topographical configuration is extremely difficult. In this study small diameter vertical holes are considered with the OD-method and a fixed platform is recommended for drilling and loading operations.

Jan 1, 1984

By Finn Ouchterlony

"Recently detailed fragmentation data from blasts fired with electronic delay detonators (EDDs) in the Red Dog mine in Alaska were presented. They include a comparison with pyrotechnic detonators fordifferent in-­-row delays in a standard pattern and EDDs in an expanded pattern. Fragmentation was measured on the belt after the primary crusher. The Rosin-­-Rammler function (RR, two parameters) was used to describe the crusher product. This was combined with the JK SimMet crusher model and the CZM blast model (Crushed Zone Model, three to five parameters) to estimate a reasonable crusher feed (muck pile fragmentation or run of mine, ROM) for each fitted product. In this way the effect of delay timing and electronic detonators on the median fragment size x50 and uniformity coefficient n for both crusher product and the blasted rock was determined. "

Jan 1, 2012

By Rob Grant, Manuel Lopez Cano, Mike Briggs, Ken Fletcher

The scorched desert sands and life giving waters of the River Nile in Egypt have been the back drop to awe inspiring engineering feats for over 4,700 years. The latest engineering marvel to grace the land of the Pharaohs is the Mubarak Pumping Station Project at Toshka. This ambitious project aims to open up an area of 607,000 hectares (1.5 million acres) of barren desert to irrigation based farming with the supply of 29 million tonnes (32 million tons) of water per day, drawn from Lake Nasser on the river Nile. It is anticipated that this currently unpopulated area of southern Egypt will soon flourish and become home to several million Egyptians who will conduct their lives around the water supplied by the 230 kilometers (144 miles) of concrete canals. An integral part of the pumping station is the intake canal. The canal was excavated in two sections – the dry excavation, and the wet excavation. The wet excavation comprised of some 5.5 million cubic meters (7.2 million cubic yards) of rock to be drilled, blasted, and excavated, from the surface of the lake. The challenge at hand was how to achieve this safely, quickly, and cost effectively, with water depths of up to 45 meters (148 feet), excavation depths of up to 47 meters (154 feet), blast production rate peaks of up to 30,000 bank cubic meters (39,200 bank cubic yards) per day, blistering summer air temperatures up to 60°C (140°F), and security concerns about the storage of large quantities of explosives in the Middle East region. The solutions to these challenges were engineered by UEE Explosives and centered around the use of a microgel bulk explosive called Rioflex™ and an international team of engineers and operators from three continents. The microgel and accompanying pumping system allowed pumping rates of up to 17,400 kg (38,400 lb) per day, and more importantly, enabled the bulk product to remain as an oxidizing matrix whilst in transport and storage, transforming into an explosive only moments before being pumped into the blastholes. This case study outlines the underwater drill and blast process employed at the Mubarak Pumping Station Project at Toshka, and the novel solutions to the unique challenges encountered.

Jan 1, 2004

By D. Mason, W. J. Birch

Blasting operations are arguably one of the most contentious areas of surface mining.Many operators carry out outine monitoring as required by Mineral Planning Authorities. However in so doing they only concentrate on the observed Maximum Peak Particle Velocity (PPV) being below the statutory limit and pay little or no attention to the measurable parameters that determine this value (e.g. scaled distance, burden, detonator type, blast type or rock type). Such practice is “monitoring to comply”. What is needed is for the operators to adopt a methodology that clearly demonstrates to the appropriate regulators that the operator is “planning to comply”. The aim of the exercise being to deliver a process that is seen to be transparent, accountable, and quantifiable, which seeks to minimise environmental impact whilst not compromising the efficiency of the blasting operations mine.

Jan 1, 2011