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By Norman Kramer, Roger Keller

The authors would like to thank Austin Powder Company for their technical support and input, specifically Stephen Harris, Jason Ryan, and John Capers of Austin Powder, without whose support this paper would not have been possible. Thanks are also extended to Nick Francis of Sandia National Laboratories and Jim Houseworth of Duke Engineering for their input regarding Performance Assessment.

Jan 1, 2000

By Stephen P. Case, Stephen Castellucci, William Parsons

In this paper, the authors present a step-by-step discussion of dimension stone production at a New England granite quarry. The quarry mines a rare pink granite which is used for facings and panels in the construction of high rise buildings around the world. The discussion includes geological considerations, block layout, drilling, explosives loading, block handling, and mobile equipment utilization.

Jan 1, 1990

By Max Pena Woolcott, Winfried Rosenstock, Maria Chappuis, Walther Hennig

"In a Peruvian-German Technical Cooperation project for the Mining Sector the ""Milpo-cut"" along with the electric initiation system has been successfully implemented in a Peruvian metal-ore mine.Specific savings in drill work and explosives consumption up to 50 % have been achieved in headings and slopes. The positive results have motivated further Peruvian mining companies to introduce the new technique."

Jan 1, 1994

By N K. Jain

"The idea of writing this article is to give correct picture about the technique in blastingindustries based on the safety aspect, basically without effecting the results thereof.Like many other sciences, blasting is rapidly advancing and research scientists are dailycreating new devices which are very reliable and efficient.The theory of explosion and all the respective changes caused by the explosives takingplace during the detonation has been brought up to the level enabling a mathematicalexpression of detonation characteristics even in comparative complex cases."

Jan 1, 1993

By Sam Oaks, David A. Smith

The new Corridor "G" Federal Highway Project in Logan County, West Virginia is the largest mass excavation highway project currently being built in the United States. Seven sections covering 14 miles of four lane highway and two connector roads will require over 30 million cubic yards of excavation. Construction is on a fast track schedule requiring the contractors to complete excavation and pavement placement in a little over 19 months. The two different general contractors have implemented several innovative Blasting and Excavation Programs to complete this project within the tight completion schedule. The paper expands on some of these unique programs that made the project a reality.

Jan 1, 1994

By Fred C. Drury

The introduction and growth of modern chemical explosives based upon prilled ammonium nitrate has been the most significant development in the explosives industry during the 20th century. These modern chemical explosives have been of incalculable value to our society. Their use has permitted a reduction of blasting costs, improved safety, and the development of new resource sources which would not have been accessible without this new technology.

Jan 1, 1980

By William C. Lane

The Pacific Northwest has an abundance of seamy, coarse granite and basalt rock. It is used primarily for road construction. Small quarries are opened nearest the road work to cut the cost of hauling. The crushers are portable. Small diameter holes 2 1/2" to 3 1/2" are placed close together to insure proper fragmentation. It is not unusual to load and shoot 100 to 700 holes 40' deep.

Jan 1, 1986

By Natalie Zeleznik, Brian Hawkins, David Bradley, Rachel Gooding, Patrick Wilson, Brian Somes, Kevin Wegman

"To perform a probabilistic risk assessment (PRA), a method of quantifying the risks associated withinfrequent high consequence events, consequence models that generate representative estimates of human health consequences for a wide variety of representative scenarios are commonly used. Criteria that suitable models must possess include: (1) input requirements necessary to generate large volumes ofprobabilistic simulations; (2) the capability to output injuries with the necessary details and resolution;(3) the ability to capture the variety of different scenarios inherent in an assessment; (4) acceptable cost and computational requirements; and (5) sufficient stakeholder buy-in for community acceptance."

Jan 1, 2017

By Eric Reale

The New York City Department of Environmental Protection (DEP) is currently building City Water Tunnel #3 beneath the city. The purpose of this tunnel is to improve water distribution to the city and to allow the DEP to inspect the older tunnels and make the necessary repairs. These older tunnels have been in continuous operation since the early 1900's. Construction on the Third Tunnel is planned in four stages. The Nelson Street Shaft, which is the focus of this paper, is part of the second stage.

Jan 1, 1989

By Richard Turnbull

Maules Creek mine is an open cut coal near Boggabri in the Gunnedah Basin of New South Wales, Australia. The mine is currently operating at an annualised run rate of 9.5Mt of saleable coal. The plan is to ramp up production to 13Mtpa. Maules Creek has multiple seams each with varying depths; the inter-burden ranges from a few metres thick to greater than 30m (98ft). Due to this, Maules Creek mine is utilising truck shovel operations rather than a cast/dozer push operation.

Jan 1, 2018

By S D. Cummings

"CRACKS CONCERN CORPORATION" Was the headline on the front page of the Terre Haute Tribune Star, March 1994. Having spent several years following up on blast-induced damage allegations made this article especially interesting. Knowing that there were no operating mines within 30 miles of this newly built, yet to be occupied building, also made the reading more enjoyable. The article went on to read, "Vigo County school officials have asked architects to find out whether some cracks in walls at the new school are due to NORMAL settling or if they indicate serious structural problems." It is obvious that if there were a mine within "Feeling" distance, blasting and the operator would have immediately become suspect as at least one of the potential causes. More alarming is that the investigation may have stopped there.

Jan 1, 1995

By Robert B. Hopler

The Hercudet ? Nonelectric Delay Blasting Cap System has undergone significant changes since the last paper on the subject was presented at the 1978 S.E.E. Conference. The changes have been made to improve reliability of the blasting machine at low temperatures, and to improve efficiency and economy in usage in surface mining. The paper includes examples of the blast design process, details of use of the new in-hole connected cap, and delay patterns which have found use in quarrying and coal stripping.

Jan 1, 1980

By J R. "Dick" Daniel

One of the more common tasks in blast management is the adjustment of: shot geometry, explosive energy, and shot timing parameters to achieve changes in blast outcomes and costs. Many of these shot parameters, once a delayed blast is initiated, are modified by the development of new free faces which change the original or static input values to dynamic values. These newly generated dynamic values are easily calculated and find use in fine tuning shot adjustments and in rationalizing blast outcomes in a systematic manner.

Jan 1, 1996

By J R. "Dick" Daniel

One of the more common tasks in blast management is the adjustment of: shot geometry, explosive energy, and shot timing parameters to achieve changes in blast outcomes and costs. Many of these shot parameters, once a delayed blast is initiated, are modified by the development of new free faces which change the original or static input values to dynamic values. These newly generated dynamic values are easily calculated and find use in fine tuning shot adjustments and in rationalizing blast outcomes in a systematic manner.

Jan 1, 1996

By J. Silva, T. Worsey

The Worsey-Silva equation determines the optimal row timing for the smallest fragmentation and allows fragmentation models to be adjusted due to row timing. The equation utilizes the concept of dynamic confinement to determine when the best time to fire the next row or sequence series would be if the smallest fragmentation is desired. Full-scale testing was conducted at an aggregate quarry in Ontario to support the theory and equation. The full-scale testing comprised six (6) blasts, two (2) different contractors, and three (3) different sequences. The test parameters were kept consistent, besides changing the timing between sequential charges to explore the timing sequence’s influences on fragmentation. From this research, the theory of dynamic confinement relating to row timing was discovered, and the equation to determine the optimal timing for the smallest fragmentation was derived. An equation to adjust fragmentation based on row timing was derived from the full-scale testing and literature review. The Worsey-Silva equation can be used with other fragmentation models as it takes the fragmentation results from the other models and adjusts them based on the row timing used. The paper explains the theory behind the equation, the research supporting the findings, and the developed Worsey-Silva equation for row timing

Jan 1, 2024

By Koichi Kurokawa, Takeo Ueda, Yoji Tasaki, Masashi Nakano

We have developed a new firing system which simplifies the handling and extensively increases the safety in electric blasting operations. Based on the principle of the transformer, this system is operated as follows: When a high frequency alternating current pulse (70-110 kHz) is applied to the lead wire and connecting wire (primary circuit), magnetic flux is generated in the transcore, and an induced current flows through the looped leg wire of the detonator (secondary circuit). Then the detonators are ignited by the induced current.

Jan 1, 1986

By Michael J. Sapko, Eric S. Weiss

The U.S. Bureau of Mines has been conducting research on the secondary explosion hazards associated with the mining of oil shale under gassy mine conditions. Explosive incendivity tests have been conducted in a 28 m~3 (1000 ft~3) gallery to evaluate the relative incendivity of experimental emulsion-ANFO blends. The incendivity was measured by determining the minimum inert stemming requirements for preventing the ignition of a methane-air atmosphere by the discharge of hot detonation products from a 5.7 cm (2.25 in) diameter borehole.

Jan 1, 1990

By S. Behera, K. Dey

This paper presents a methodology for finite element (FE) modelling to analyse the total deformation of rockmass under blast-load, with a focus on predicting backbreak that may occur during surface blasting operations. Backbreak can result from improper use of explosive energy, leading to damage beyond the excavation zone and jeopardizing operational safety and productivity. The paper highlights the impacts of backbreak on bench stability, excavator operation, drilling operation, flyrock generation, and improper fragmentation and boulder formation in surface blasting. However, prior estimation of extent of rock breakage zone can provide an idea to formulate the blast design to control the backbreak. While vibration-based prediction models are commonly used to estimate backbreak, they require physical blasting experimentation. To overcome this limitation, the paper describes the development of a FE model using ANSYS Explicit dynamics, which simulates rock blasting and calculates the total deformation of the rockmass. The rockmass deformation is modelled using Drucker-Prager (D-P) strength model with the Jones-Wilkins-Lee (JWL) equation of state for the explosives. The accuracy of the FE model is evaluated through physical experiments, and the results are compared with the vibration models. The FE model demonstrates close proximity to physical observations as well as vibration model result in predicting backbreak, thereby offering a promising alternative to vibration-based prediction models. The primary objective of the study is to predict the response of the insitu rockmass to explosive blast loading and determine the effective rock breakage zone.

Jan 1, 2024

When CIL presented their new theory of the Breakage Process and Delay Blasting at the 74th Annual Meeting of the CIM in 1972(1), there was hardly any open pit operation in Canada that was using longer than 25 msec. delays. To the contrary, 10 and 15 msec. surface relays were common, which in our opinion were no delays at all for open pit blasting.

Jan 1, 1979

By D O. Doehring, W A. Charlie, W A. Lewis

The detonation of explosive charges releases large quantities of energy that can produce rock and soil deformations far from the detonation point Extensive data are available on blasting in general and on the performance of certain structures subjected to blast vibrations. However, only limited information is available on the performance of earthfill dams and other hydraulic structures subjected to blasting. The limited data indicate that, whatever the cause, one or several cycles of repeated strains in earthfill dams may cause residual porewater pressure increases. Limiting the peak particle velocity to less than 2.5 cm/s for operating dams constructed of or having foundations consisting of saturated, loose sands or silts and to less than 5 cm/s for other earthfill dams, should keep strains below the threshold strains required for residual porewater pressure increases to occur. Porewater pressures should be monitored throughout a blasting operation, and they should be allowed to dissipate, if necessary, before subsequent charges are detonated.

Jan 1, 1987