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By J Lyall Workman, Peter N. Calder

"Presplitting is a technique mines and quarries may use to produce high quality final pitwalls. Damage from backbreak can be minimized, thereby insuring the final pit walls standat the designed angle. Thus costly excess waste removal is avoided. Safety in the pit isenhanced. Control blasting is an essential component of procedures to maintain the stabilityof final pit walls prone to failure."

Jan 1, 1993

By Baron Fidler, Dave Lilly, Matt Budin

Cumulative sum (CUSUM) statistical process control methods have been used in many industries to monitor quality control results. CUSUM charts are a method to determine when small changes in data indicate a major change in results. E.S. Page at AT&T developed the method in 1954. In many blasting situations, vibration and air blast readings vary slightly from blast to blast. Whether the change is significant or not can be hard to interpret from the raw data. CUSUM charts can assist in determining whether a major change is taking place and when the change began.

Jan 1, 2009

By Mark S. Stagg, Rolfe E. Otterness, Stephen Rholl

The Bureau of Mines is engaged in research to develop and test high explosive fracturing and rubblization techniques that will enhance ore body permeability and thus increase recovery during in situ mining. The natural permeability of many ore bodies is too low to allow successful in-place leaching. These deposits could be profitably mined if flow rates of leach solutions could be increased. Blasting represents a potentially low-cost and effective permeability enhancement technique.

Jan 1, 1991

By L M. Stodart

In the increasingly competitive environment of the 1990's, there is a need to provide the users of explosives with accurate and immediate information. Research has shown that information technology alone will not provide companies with a sustainable competitive advantage. However, where information technology is used to assist the development and enhance the performance, of the employee sustainable competitive advantage can occur. A Performance Support System is a tool that combines explosive's theory, government regulations, and site specific knowledge in an easily accessible computer program. In this paper five areas are addressed where a Performance Support System can assist the user: as a reference source, in an assistant or advisory role, as a instruction aid, in regulatory compliance, and as an operations monitor.

Jan 1, 1993

By Vaughn Bowns, Allen Stanley, Brian Redeker

"Running casing in drilling operations is often complicated by boulders or large cobbles.Past practices of dealing with these have included use of drop hammers, attempts to drillthrough or around the boulder, contact explosive charges and even pulling the casing andrepositioning the hole. All these methods are time consuming, expensive and offer noguarantee of success. In this paper a different method of dealing with these boulders ispresented that promises to be faster and less expensive with a much higher success rate.This involves using a light plastic conduit pipe to place a shaped explosive against theboulder. It requires no special tools or techniques not commonly in use in the drilling andblasting industry."

Jan 1, 1993

By C A. "Hawk" Hanger

"The paper that will be presented is an in-depth study of sequential blasting using standardnon-electric shock tube down hole timing along with surface M.S. connector timing.Included also will be a discussion on the advantages in fragmentation, digability, oredilution' and ground vibration versus the common practice of row by row blasting. Alongwith the written presentation, several visual illustrations will be included. The visuals willrefine the actual direction and predicted movement of the shot involved."

Jan 1, 1993

By Kenichiro Yamamoto, Masaharu Murakami, Toshio Matsuzawa, Yoshiyuki Ikeda

In a series of tests, we examined the dynamic shock resistance of Emulsion Explosive in water and compared it with that of Dynamite and Slurry Explosives. Both the distance between donor and acceptor charges and the delay initiation timing of the acceptor charges were varied. The resistance to dynamic shock varied with the properties of the explosive. In the case of emulsion explosives, there seems to be a certain proportional relationship between the critical detonation distance and the delay initiation timing. Some blasting results with emulsion explosives are described.

Jan 1, 1983

By William H. Snyer

A relatively inexpensive, very fast response photo-optic/fiberoptic system has been conceived, constructed and employed by Denver Research Institute (DRI) to measure charge breakout uniformity on the surface of a very large ANFO detonation. The new equipment and technique was coined OWL (observation without leads). Its unique design provides the ability to monitor or measure detonation velocities and/or detonation breakout characteristics without fiberoptic or any other direct contact with the explosive. This system has proven to be versatile and has been used to measure surface breakout simultaneity on large ANFO detonations, munition case breakout times and velocity of detonation (VOD).

Jan 1, 1990

By Catherine T. Aimone-Martin, Kristen Kolden

In August of 2013 the USDA Forest Service (USFS) blasted bedrock at the base of a waterfall in Kanalku Creek within the Kootznoowoo Wilderness Area on Admiralty Island in the Tongass National Forest located in Southeast Alaska. The purpose of the blasting was to widen and deepen a plunge pool at the base of a waterfall complex considered to be a partial barrier to migrating sockeye salmon. Drilling and blasting to remove 12 to 15 cubic yards of rock occurred over a two day period.

Jan 1, 2015

By P. Ross, O. Rielo, P. Katsabanis

Selection of delay times to optimize fragmentation has been a controversial topic among researchers and blasting practitioners. The paper reviews all available experimental information, ranging from small and medium scale tests in geologic materials to small scale tests at the laboratory and synthetic materials, simulating rock. Tests have been re-analyzed and discussed in terms of the information they present and the limitation of the testing environment in representing actual conditions. New results obtained from blasting experiments in specimens made of a grout have provided a clear picture of the effect of delay on fragmentation. The grout used has a strength of 60 MPa (8700 psi), density of 2.5 g/cm3 and P-wave velocity of 4000 m/s (13100 ft/s). Each block was placed in a yoke to eliminate unwanted reflections and the desired delay was obtained using the appropriate length of detonating cord between holes or sub-millisecond electronic detonators. Delays ranged from 0.1 ms/m (0.03 ms/ft) of burden to 16 ms/m (4.9 ms/ft) of burden. Fragmentation was obtained using screen analysis of the collected fragments. Delay time has been shown to be a significant parameter affecting fragmentation and back break. Generally larger fragments and less back break was observed at short values, while fragmentation somewhat deteriorated at significant delay times, compared to what was observed at intermediate delay times. The work is now extended to include the effect of energy partition on fragmentation as well as the effect of initiation point and coupling ratio.

Jan 1, 2014

By Pat McLaughlin

Blast design in the construction industry has often been based on past practice or powder factors. This is to some extent understandable, since construction projects do not have the longevity of mining or quarrying operations and therefore have less opportunity to pursue potential improvements. The main concern of the operator is whether or not the technique will work, and at what cost to the downstream processes. Time, not long term savings, is of the essence.

Jan 1, 1994

A simple and cost effective technique to increase fragmentation and burden velocities without making major modification to the overall blast design is with ALTERNATE VELOCITY LOADING OR BOOSTERING OF ANFO. The technique requires the placement of a cartridge or slug of explosive, having higher density and detonation velocity than ANFO, every few feet in an ANFO column. The greater the difference in density and detonation velocity of the Alternate Velocity Load to ANFO, the more pronounced are the results. Emulsions were selected as the Alternate Velocity test explosives because they detonate closer to ideal conditions than most other commercial explosives.

Jan 1, 1989

By Richard Curtis

Optimum Colliery is presently experiencing a shortfall of stripping capacity in order to meet its production requirements. Due to the long dragline procurement times, several alternative stripping methods were evaluated in order to alleviate this shortfall in the interim period. Based on the experience gained at the mine. The writer will discuss some of the important factors which influence dragline performance and show how these factors may by used in a theoretical approach to analyse various dragline applications.

Jan 1, 1990

By Jorge Cardenas, David Martinez

Blasting-induced vibrations can be predicted with high precision, allowing for the optimization of sequence design, delay timing, and charge configurations to minimize their indirect impact on rock masses. This optimization leads to a reduction in peak particle velocity (PPV) and dominant frequency at monitoring points. However, a crucial aspect of slope safety is estimating the degree to which vibrations influence stability through numerical modeling of the dynamic response. Slope stability is closely linked to rock mass strength, the predominant failure mechanism based on discontinuity orientation relative to the slope face, and the pre-existing stability conditions before dynamic alterations occur. Blocks, wedges, and planar failures tend to slide under lower vibration levels and are more susceptible to resonance, particularly in fractured and low-strength rock masses. To evaluate the interaction between rock mass and vibrations, photogrammetry and artificial intelligence were employed to identify discontinuity families at vibration monitoring sites. This data facilitated the development of artificial discontinuity networks (DFN), which replicated a discontinuous medium within a numerical finite element model. The input signal was recorded at the slope base using triaxial geophones and incorporated into a discontinuous numerical model. The output signal was estimated through finite element analysis and subsequently compared with geophone measurements taken at the same location. Based on real-world output signals, damping parameters and the model’s natural frequency were adjusted to align both frequency spectra. Using the calibrated parameters, vibration records from various blasting projects at different distances were applied as input signals until slope failure was induced, thereby defining maximum allowable vibration limits in terms of PPV and frequency at the monitoring point. This approach provided a framework for optimizing sequence designs, charge configurations, and delay timings to enhance slope safety and prevent failure due to blasting-induced vibrations.

Jan 26, 2026

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 Bruce Vandenberg

A 3D, PC based computer program is currently under development by Blasting Analysis International, Inc., to analyze the kinetics of full scale blasts with two or more high-speed motion picture cameras.

Jan 1, 1990

Since the ecrly 1970's several factcrs have changed. In the East the larger tracts of coal mined with large eauipment are being dePleted, The cost of moving the larger equipment from small tract to small tract becomes eccnomicallv unattractive, Conseauently, the tracts are being mined with smal!er draglines or with loader/truck haulage combination, This has resulted in a major increase in the cost of moving a cubic yard of overburden,

Jan 1, 1989

By Michael Peterson, Robert Davinroy, Robert Rapp, Gregory Hempen, David Herzog, Thomas Keevin

Fish sampling in a deep-water, high velocity, environment is extremely difficult. Conventional techniques such as electro-fishing and netting have been limited to depths generally less than 7 meters (m) and velocities below 1 meter per second (mps). The goal of our study was to sample a bendway weir field on the Mississippi River to assess the effects of the weir field on the fishery. In a bendway weir field, depths can exceed 20 m, and velocities can exceed 3 mps, making conventional sampling techniques inefficient.

Jan 1, 2002

By Joseph Daly

An investigation into inaccurate scatter of pyrotechnic detonators led to the innovation of utilising existing (every day) equipment in a manner to accurately determine the true scatter of detonators. This can then be utilised to determine the accuracy of a particular batch of detonators.

Jan 1, 2014

By Dale Preece, Ayman Tawadrous

This paper presents a number of examples of three-dimensional blast modeling in both surface and underground environments that include time-delay explosive decking. These examples include: 1) quarry blasting, 2) coal seam protection blasting, 3) mineral mine blasting with high energy time delayed decks, and, 4) underground single-level/single-shot drawbell blasting.

Jan 1, 2014