Search Documents

By S Burchell

During the past few years, high-speed cameras, laser surveying equipment and photogrammetry have become standard tools for recording blast geometry and results. While laser profiling yields accurate 3-D measurements, most cameras capture only two-dimensional images. Attempts to extract 3-D information from photographs have been unsatisfactory. Recent advances in electronic imaging and computer programming have made it possible to develop a 3-D computer based analysis system which can capture and measure 3-D images quickly and accurately. This paper describes the technology to create 3-D images and to analyze blast geometry before, during and after the blast.

Jan 1, 1992

By Virgil J. Stachura, Calvin L. Cumerlato

The U. S. Bureau of Mines is conducting research on blasting methods that reduce highwall overbreak and the associated rockfall hazards. This paper presents the results of tests using a low-density water gel to improve the quality of air-decked presplit blasts at a surface coal mine in New Mexico. The explosive's specific gravity averaged 0.50 and was bulk loaded using a modified truck which injected the gassing agent. Reductions in overbreak and resulting rockfall were achieved in comparison to a highwall presplit with ANFO. The test sections used 15° angled blast holes and resulted in 1,119 m (3,672 ft) of air deck presplit highwall using a low-density water gel which was then compared to 894 m (2,934 ft) of highwall shot with an ANFO air decked presplit design. The total quantity of explosives per hole ranged from 68 to 113 kg (150 to 250 lbs) and the 27 cm (10-5/8in) holes were 19- to 33-m (62- to 108-ft) deep on 5.5 m (18-ft) centers. Periodic visual examination and photographic surveys of the highwall test areas were used to document the amount of rockfall. In addition, laser profiles of selected sections were conducted to further delineate the damage and highwall contour differences.

Jan 1, 1995

By E Emery Gray, Gary Ard

Each year when hundreds of Engineers and Specialists in the explosives industry meet for the SEE Annual Conference, new ideas are exchanged and new business relationships formed. Harbert Construction Corp. and EGA, Inc., a company specializing in drilling and bIasting, formed such a relationship through mutual interest in such a manner.

Jan 1, 1981

By Joshua Hoffman, Braden Lusk, Perry Kyle

With the advent of any new technology comes the necessity of fully understanding the mechanics of that technology. The Shock Tunnel is one such technology that provides a cost effective means of simulating large-scale explosions while requiring a fraction of the explosive and space. Although the technique is known and practiced, the dynamics and mechanics of this technology has yet to be fully understood. A relationship between the energy potential of a given explosive and the energy realized at a set of distances was determined. This data was then compared to the energies realized from the same explosive when utilized in conjunction with a shock tunnel. A relationship between potential and realized energy outputs from explosive based shock tunnels exists and the understanding of this relationship would allow all for predictions to be made to forecast a specific amount of explosive required to produce a desired energy output. This energy output should then be relatable to peak pressures produced via the shock tunnel. Two shock tunnels are currently accessible for this study, the first under the direction of the University of Kentucky, and a second under the direction of the Missouri University of Science and Technology. The two shock tunnels differ in dimensions but share common construction materials. Energy realized from a shock tunnel is hypothesized to be a function of the shock tunnel’s dimensions. This study explores how different geometries affect the shock tunnel’s performance; this exploration is broken down into three phases. Phase 1: Open arena testing in which theoretical energies produced by the detonation of small (<1.0 kg) charges are compared to actual experimental values. Phase 2: Shock Tunnel testing in which realized energies are experimentally recorded for the UK shock tunnel. Phase 3: Analysis of the data to lay down the ground work for producing a pressure-forecasting tool given shock tunnel dimensions and explosive characteristics with the possible detection of avenues for optimization of shock tunnels.

Jan 1, 2009

By Lina Lopez, Jose Sanchidrian, Jean Du Mouza, Essaieb Hamdi

This paper evaluates the actual energy delivered by the explosives used in the fragmentation of rock during blasting vs. the available theoretical explosive energy. The evaluation of the fragmentation energy of the blast is first done. Fragmentation by blasting can be seen as a process in which creation of new surfaces within the rock mass is made by generation of new cracks or extension of pre-existing ones. From this idea, the fragmentation blast efficiency can be assessed as the fraction of the available explosive energy used for creation of new surfaces. The evaluation of new cracks area created by the blast is based on the SIMBLOC methodology and the corresponding fragmentation energy is then obtained by the Griffith theory. Secondly, the amount of energy delivered down to a certain pressure or volume along the detonation product expansion process, given by the useful work, is calculated. This is done by first determining the CJ state of the reacted explosive and subsequently performing an adiabatic expansion calculation of the detonation products from that state. W-Detcom code has been used for the calculations using the BKW equation of state with the Sandia parameter set. The fragmentation energy and the useful work are calculated for blasts performed in two mines in Spain. Multiple regression is applied to the results in order to give an assessment of the better description of the explosive energy .

Jan 1, 2002

By Goran Cirkovic, Zvonimir Ester, Josip Krsnik

During the reconstruction of the motorway Zagreb-Krapina three reinforced concrete bridges were demolished, for their width was not adequate for the new motorway. Demolition of the three bridges was carried out by blasting as duration of the traffic cut on the motorway and the railway was limited to maximally 4 hours. During that period of time the demolished bridges had to be removed. Therefore, very tiny granulation was requested suitable for loading and not endangering the surrounding structures. Before each of three main blasting, trial blasting were carried out including the seismic measurements registering the seismic effects. The nearest residential building was at the distance of less than 30 m from the place of blasting. Additional difficulty was the fact that by each of the three bridges there is a new bridge, with minimal distance between the old and the new bridge being 30 cm. As each of the bridges is of different construction and of various thickness, particular blasting technique has been prepared for each one of the bridges.

Jan 1, 1997

By Michael A. Barbaglia, Mark William Withey

The lift shot is an essential blast design in the execution of mine creation and expansion plans. Whether it be opening a new quarry, creating a new level in an existing operation, or for control of water, lift shots are utilized to create the desired results. Lift shots by their nature differ from conventional production blasts because they have no free faces for relief of the blast. Due to this fully confined state, the primary direction of the rock movement is vertical, and the potential for excessive vibration and fly rock generation is great.

Jan 1, 1994

By S Lukovic, Vishwa Bhushan, Calvin J. Konya

Effect of each of these variables has been well characterized for ANFO. This paper presents results of underwater energy measurements for one watergel and one emulsion type of slurry explosive which were initiated by 3 types of initiators (one electric and two cords of different strength) in 2 and 3 inch diameter steel pipes. Results of this 2 x 3 x 2 factorial experiment show the effects of detonating cord on energy released by the watergel and the emulsion explosive. Effect of diameter and its interaction with cord strength have also been characterized for the two explosives.

Jan 1, 1986

By Ronald Thomas

The scope of this paper is to examine the growth of safety in an individual and offer new goals in that development. The paper will examine the individual's natural growth and show how it parallels the individual in a safety environment. An individual's new goals for safety include more than the standard accident-free conditions. The new goal strives for a safer working environment where unsafe acts are eliminated through independent knowledge and an individual's growth of interdependency in safety related areas of concern. It will explain how this goal cannot be reached unless driven from the top down in an organization but empowered from the bottom up. Various reference or support organizations will be covered. These organizations deal with safety in mining and explosive use of manufacturing. Other support organizations exist but since this paper is "Back to Basics" only a few major groups will be covered.

Jan 1, 2001

By Thomas C. Jones

The purpose of this paper is to disseminate new information for nonelectric blasting in trenching and construction work. The presentation is not designed or intended to discredit conventional electric detonators or use of MS connectors and cord. Its sole purpose is to inform the S.E.E. of new and exciting benefits realized by the use of the Hercudet non-electric system in the construction industry.

Jan 1, 1984

By Larry Schneider

In 1998, the Blast Vibration and Seismograph Section of the International Society of Explosives Engineers formed a working group to collect and compile a list of regulations limiting ground vibrations from blasting. The goal was to locate those countries, states, provinces, and cities that have such regulations, identify which governmental body enforces them, and determine what limits on ground vibrations are imposed upon the blasting operations. In the course of this study, data was collected from over 60 jurisdictions where peak particle velocity restrictions range from non-existent to very stringent. Some of the regulations were found to be based upon standards grounded in good science, while others possess little or no technical justification. This presentation will summarize the findings of the subcommittee, focusing primarily on what the limits are, which type of blasting operations must adhere to them, and to what structures they apply. The degree to which these regulations are based upon valid scientific and engineering research will be discussed. A listing of specific locations having such regulations and information about those regulations will be provide

Jan 1, 2000

By Paul Worsey, Robert Sickler

Today, America's mining and construction industries are faced with operating under a condition of reduced profit margins. This makes the implementation of new technology far more sensitive to investment return than ever before. For this reason it is imperative that every effort be made to insure that new equipment and processes be designed to maximize their impact on improved quality, reduction in production cost and enhancement of safety. Using these principles as a foundation, a study was made to evaluate potential automation techniques for the blasting industry.

Jan 1, 1987

By Duane A. Houkom

Down time in the Oil Refining and Petro Chemical Industry is extremely expensive. Each day of non-production may easily cost several million dollars. Explosives have been accepted by this industry to solve many of its problems. Explosives offer a solution which is faster, more economical and most important, safer than many of their methods. Our specialties for these industries include: Refractory removal, industrial cleaning, metal cutting and concrete removal. This report does not include information on concrete removal.

Jan 1, 1982

By Joseph Trocino, John Anderson, Stephen Murray

This paper describes the development of LEXFOAM® (Liquid EXplosive FOAM) as a unique low density explosive, and its successful application as an effective tool for "in-place" demolition of landmines and unexploded ordnance. Explosives research using aerosol technology led to the development of LEXFOAM whose components are safely transported and stored as flammable liquids. These components are mixed on site to produce an explosive foam, which enhances safety and minimizes logistical problems. Hand-held, Backpack and Palletized Delivery Systems form a versatile family of dispensing systems to suit any application.

Jan 1, 1998

By James E. Jr Hargroves

With the ever-increasing population growth and modern trend to urban development, the expansion of utilities is a stable, mad or, and constant source of income for many. Blasting is a "necessary evil" to the utility contractor. It can make or break even the most solvent. Housing development expansion and higher treatment of effluents are causing utilities to appear in more congested areas. This paper discusses some of the aspects of utility blasting in the State of Virginia. Consideration is given to bid procedures, pre-blast surveys, record-keeping and practical application.

Jan 1, 1977

By Marcus Neves, Eventomar Junior, Adilson Castro, Leandro Silveira, Sérgio Augusto

The collapse of the Vale S.A. mining tailings dam in 2019, a tragic event that shook Brazil and the world, had consequences that transcended the immediate pain and devastation. Among them, the suspension of rock blasting activities in several mines in the Quadrilátero Ferrífero region of Minas Gerais, Brazil. This measure, taken as a precaution and with the aim of ensuring the safety of nearby geotechnical structures and the population, had a significant impact on the mining production chain. To overcome these challenges and resume blasting activities in a safe and sustainable manner, the mining industry has been dedicated to developing and improving solutions. One of the promising alternatives is the signature hole technique, used in conjunction with attenuation laws. The complex geology of the Quadrilátero Ferrífero, with lenses of compact ores immersed in friable materials, the presence of discontinuity families, and the emergence of geological faults, requires detailed analyses and specific adaptations of the signature hole technique and constant monitoring of the vibrations to calibrate the attenuation laws to ensure compliance with permissible limits and safety of the operations. To demonstrate the methodology, a case study in Abóboras Mine was described. Additionally, the challenge of achieving the desired level of production while controlling vibration and slope damage has driven the development of new charging and timing techniques. To address this challenge, a comprehensive approach was undertaken. A substantial database containing more than 4,000 registers of blasting-induced vibration events from 520 blasts was meticulously compiled from 2020 to 2023, 6 different attenuation laws were established and continuously calibrated with 99.3% of compliance regarding permissible limits of vibrations. The successful implementation of these actions allowed for the resumption of blasting, increasing production from 10 million metric tons to 43 million metric tons per year assuring sustainable operation.

Jan 21, 2025

By Jesús V. Saccsa, Kenji B. Loayza, Erick M. Condori, Jorge A. Velásquez

This research investigates how to reduce manufacturing costs of a safety fuse composed of black powder, replacing its ingredient NO3K by NO3Na for processing, and contributing to minimize costs per blasting.

Jan 1, 2017

By Jeffrey N. Deisher, H Y. Fang, Richard P. Scheller, Robert M. Koerner

The need to adequately quantify cracking in structures in the vicinity of blasting activity becomes more important each year. This urgency comes about through a growing number of complaints and lawsuits between the various parties involved, i.e., operator/owner, government, and complaintant. It is felt that existing rules and regulations (mainly based on peak particle velocity of the soil or rock adjacent to the structure in question) fall short of such quantification and lead to confusion in adequately assessing structural damage.

Jan 1, 1977

By S. Klerkx, R Battulwar, J Valencia, J Sattarvand, E Emami, M. Soleymani Shishvan

A new technology for energy distribution optimization, supported by NIOSH.

Feb 1, 2020

By Francisco Sena Leite, Vinicius Miranda

Mine blasting is directly associated with ground vibration. If these affect critical structures (buildings pit walls, etc.) they must be mitigated to reduce the environment and social impacts. Vibration monitoring and control is one of the most important procedures in blasting because it will impact short and long term incidents associated with this blast effect. Technology moves ever forward, and today we have personal devices that are equipped with an array of sensors, for that reason the authors decided to investigate the possibility of using a personal device to do vibration control. This case study compares the same blast measured with a traditional seismograph and a smartphone. To validate this new methodology, attenuation laws were built with data from a traditional seismograph and a smartphone application. Predictions were also made prior to a set of blasts. Residual analysis was used for data validation from the two different sources. From the performed analysis, to prove the validity of this new methodology, the normality tests for statistics residues analysis proves that it is possible to infer that the model has a null residual mean and a small residual error. The achieved results show the accuracy of these devices, the authors pretend to show the potential of this equipment and open a completely new door for vibration analysis.

Jan 1, 2018