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By Kevin Cole, Dennis A. Clark, F William Laslow

Since 1976, the Metropolitan Sanitary District of Greater Chicago, (MSDGC), has commissioned the excavation of a tunnel system in the Chicago area, hundreds of feet below the surface in solid limestone. This paper outlines the blasting patterns, explosive selections, and monitoring techniques used to assure a satisfactory job completion, following the specifications.

Jan 1, 1982

By Joshua Micah Hoffman, Catherine E. Johnson

The recruitment and retention of future talent into the explosives industry is becoming increasingly important. One potential area from which future talent can be recruited is local student chapters. Many of the student chapters are closely connected with engineering programs. While this makes sense and both entities benefit from these arrangements, there is a trend of job placement primarily in the engineering industry. Before the explosives industry can begin to compete with other industries, it should be determined what is drawing the students into these other fields. The work presented in this paper sought to better understand the collegiate student population from which a portion of future explosives professionals will emerge. This was done through the use of an anonymous online survey distributed to the student members of the International Society of Explosives Engineers, as well as, members of SEE student chapters. The survey contained questions about future job and career plans, ideal job placement, and expectations of salary. The purpose of the survey was to determine what these students expect or require from a career in the explosives industry. This information can help steer recruitment activities and job offers. Through understanding what is incentivizing these students who have accepted or plan to accept jobs in other industries the explosives industry can better posture itself to be more competitive in recruiting from the collegiate talent pool.

Jan 1, 2014

By Pierre Allard, Wilfrid Comeau

Near-field and close-in blasting can be safe and efficient, near engineered structures, if the dynamic reaction of structural members to blasting vibrations are considered. Safe particle velocity criteria can be derived from allowable safe static flexural deflections and critical frequencies. Control of close-in blasting can be accomplished using low-pass filtering of the particle velocity signal at the critical frequency. The CETE Mediterranee laboratory at Aix-en-Provence, France, a branch of the Ministry of Roads and Bridges has -pioneered this approach and successfully applied it to major road cuts and tunnels in built-up areas, as well as a major powerhouse expansion project in Africa. This approach is presently being used for a spillway rehabilitation project in Quebec, Canada. This paper exposes- the theoretical aspects and gives case histories of its use. The SCS-15 an automated, peak reading, data acquisition device is described.

Jan 1, 1991

By John L. Floyd

A personal computer is a valuable tool for blast design and analysis. Programs designed for the personal computer, such as the electronic spreadsheet, can be used for a wide range of applications. The spreadsheet formats discussed in this paper are used for explosive comparison, inventory/shot records, and timing design analysis. Each template can be adapted to fit the individual needs of the end user. An example of a graphically orientated blast design program, written in the BASIC programming language, is also discussed.

Jan 1, 1987

By Kirstin Girdner, Vicki Seppala, Tom BoBo, John Kemeny, Mike Higgins

Optimal blast fragmentation is fundamental to all phases of comminution. Changes in blast design may affect efficiency and productivity of downstream processes such as crushing, milling and leaching, resulting in cost savings or losses.

Jan 1, 1999

By N L. Thomas

Hole size affects many factors which directly influence fragmentation in the muckpile and hence, the cost effectiveness of the entire operation. These factors include production capability, explosives and accessories efficiency and usage and drilling accuracy. In addition, hole size should be chosen to suit the geological conditions. The paper concludes that the optimum hole size is generally the largest that can be used commensurate with production and environmental considerations.

Jan 1, 1986

By Ankit Jha, Sudarshan Rajagopal, Purushotham Tukkaraja

Geologic structures are one of the crucial parameters in blast design. Structural geology and rock properties influence drilling patterns, blast layout, and initiation systems. A comprehensive understanding of structural characteristics is essential to achieve the desired blasting objectives. This paper aims to identify geologic features in a bench using images obtained from the drone. Images obtained from mine site are annotated for geological features such as faults and joints. Semantic segmentation of images is achieved using an encoder and decoder structure available in the machine-learning pipeline. The encoder consists of initial convolution and pooling layers to capture essential features of the geology and rock patterns from two-dimensional RGB images. Batch normalization is used to put all the features on the same scale. These images are then inputted as training data for the machine-learning algorithm. Machine learning model is trained on sub-section of interest to achieve reasonable accuracy. Initially, 1000 best annotations were used to train the model and additional samples were added later to achieve more accuracy and avoid iteration of machine learning model in wrong convergence. After the model achieves reasonable accuracy, it is used to recognize geological features on new data. Geological features identified on the new data can be used by the blasting crew in blast design and keeps the geological maps updated that can help the geotechnical team.

By Frank Hammelmann, Peter Reinders

This paper briefly describes the past history of blast management. A modern blast management suite is then presented which demonstrates the current capability of the functional link between an electronic blasting system and blast design software. Finally, we look at the potential of tomorrow’s fully integrated blast management systems. From the first time blasting was introduced in mining as part of the production process, blasting technology and blast management have been interconnected. Over the past decades we have gained more recent experience with the new electronic blasting systems in mining, quarrying and construction. To start, the primary focus of electronic blasting was to increase timing accuracy. However, since then the technology has gradually developed, broadened and opened up new possibilities, including impressive flexibility in blast design and full in-situ verification of system functionality. To support this capability, modern electronic blasting systems are specifically designed to facilitate full two-way transfer of information between the office-based blast management software and field-hardened equipment. Blast management systems now comprise a suite of expert systems for planning, documentation, analysis, measurement and prediction of blasts. Within this blast management suite, the blast design software allows the transfer of the blast design information from a PC directly to the hardware of the electronic blasting system. The future development of this technology holds huge potential for the blasting industry.

Jan 1, 2004

By TH Kleine, AR Cameron

Size assessment of fragmentation is all about estimating the population of fragment sizes in the rock pile. A knowledge of the size distribution of particles can be used in applications from evaluating the stability of a waste dump, to optimizing a blast design to achieve a required fragmentation, to on-line control of a crushing and sieving operation.

Jan 1, 1997

By David E. Siskind

"This report describes recommended vibration monitoring and assessment practices at blasting sites.Intended is regular monitoring, tracking of trends, responding to complaints of alleged damage, and the technical and data aspects of addressing lawsuits."

Jan 1, 1999

By Stephen Hamilton

This case history details the issues surrounding the rock drilling industry’s growing demand for straight holes, the importance of straight holes and the introduction of a new production drilling systems that can effectively and economically drill a true bore hole. Since the introduction of the hydraulic rock drill, the rock drilling industry has asked for a drilling system that would provide the fast penetration and low operating costs of Top Hammer drilling systems combined, with the directional control of Tube or DTH drilling techniques.

Jan 1, 1999

By Calvin Konya, Anthony Konya

Presplitting is a form of blasting that when executed properly will create a smooth wall that will minimize secondary conditioning. In recent years, presplitting has become a popular technique to be used in both the mining and construction industries, however, presplitting fails on many occasions because of ‘geologic conditions’. This is typically because of improper explosive loads consisting of overloading and underloading blastholes. In this paper the authors introduce new factors such as a presplit factor which varies for different rock types, selection criteria for the spacing of presplits, and the optimization of explosive load for the technique of Precision Presplitting.

Jan 1, 2017

By Francisco Sena Leite, Raquel Sobral, Vinicius Gouveia de Miranda, Céu Jesus

"This document investigates a newly developed technique with the objective of improving terrain triangulation models (horizontal/sub-horizontal and vertical/sub-vertical terrains), mainly blast free faces. The algorithm uses multi-linear regressions to generate the best point cloud projection plane by applying the residues modulus minimization so as to create the finest 3D triangulation model. A change of base is required to create a new set of coordinate axis and generate completely new projection planes. The projection plane residue analysis is inferred in order to avoid or reduce the outlier points. The dataset is composed of 12 terrain models obtained from photogrammetry and a 3D Laser equipment thatgenerates georeferenced cloud points. This new technique is validated by the analysis of the obtainedcritical burden by the improvement of the general aspect view of the terrains and the capacity of outlier’s detection. The result and the quality of the algorithm demonstrates the improvement in the triangulation mesh, reducing errors in the calculation of over/under burden, free face volumes, cavities and, therefore, in the estimations of clearance/safety distances."

Jan 1, 2017

"Large scale open pit mining and quarrying operations dictate safe and reliable pit wall stability. The current approach of employing the particle velocity-scaled charge distance approach to estimate and minimize damage to residential structures is considered inadequate to protect rock slopes. This study utilizes close-in blasting vibration data as input to an advanced 2D numerical code to study its applicability to serve as a predictive tool in terms of blast-induced rock slope failure. Two tri-axial accelerometer stations, consisting of high-frequency and high-amplitude (20 kHz, 100g) sensors, located within ~100m of the blast, but at two different bench levels, were used to monitor a production blasting in a quarry. The production blast consisted of double-decked explosive loads in 155 mm (6 in) diameter holes, with an inter-deck delay of 42 ms, and each deck consisting of 130 kg (285 lb) of emulsionexplosive. The blasting vibration data obtained at the two bench levels were critically analyzed, and thevibration results served as input to the numerical model consisting of a single rock block with a 45 degree persistent joint plane but with specified strength properties, significantly different from that of the intact rock. The model was able to characterise progressive accumulation of damage in the form of micro-cracks along the joint surface as a function of the vibration load from successive explosive decks. The results showed that such a numerical model can serve as a very good diagnostic and predictive tool, when backed up by careful vibration monitoring and further supported by detailed slope monitoring."

Jan 1, 2017

By Frank Lucca

This study is based on a six month study performed for Lee County, Florida. The study was based on blasting for land development and how this type of blasting affects structures. The study is investigates peak particle velocities and the relationship to other environmental and manmade forces that affect structures. The study also explores the effect of geology on blast vibration. After completion in Lee County, the study was then continued in the quarry environment in Vermont and extremely tight blasting environment of New York City. Charge diameters were 127mm (5 inches) or less.

Jan 1, 2006

By Nadir Plasencia, Rogerio: Neves Mota

The evaluation of vibrations induced to build structures is one of the main concerns when dealing with blast works. EDP, the main Portuguese producer of electricity is presently incrementing energy production in some old hydropower dams by installing new production plants. The need for not disrupting production during the upgrading works causes some concerns related with vibrations induced to the production engines. Vibration estimation was performed in two of these dams, constructed in a granite environment, by performing controlled blasts. For each dam site, some vibration transmissivity laws were developed with the fitting process.

Jan 1, 2008

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 Alastair Torrance, George Boucher, Roger Keller

An investigative blast programme has been carried out to provide information on the best blasting methods to excavate Chek Lap Kok island in Hong Kong for the new airport. The objectives of the programme included the assessment of a range of blast design parameters and their influence on fragmentation. This has been evaluated by physical assessment, photo digitising of the muckpile and computer predictions. In addition, a model to predict the three dimensional muckpile shape has been successfully calibrated.

Jan 1, 1992

By Jim Breedlove, Stephen P. Case

When a major ground subsidence occurred in the AKZO Salt mine at Retsof New York, the company was forced to pick up their production from a lower mine level. Before full production on the lower level was possible, an escapeway and ventilation shaft would have to be constructed. Construction of a shaft under emergency conditions required some special techniques. Dynatec Mine Construction, Inc. of Lakewood Colorado was awarded a contract for the project.

Jan 1, 1995

By He Guangyi

During rock blasting in extending deep cutting from Jiu Li Mountain to Dong Zhuang Village in Jiao Zhi Railway line, we have drilled deep hole with large scale diving drilling machine and successfully carried on controlled blasting. This has provided new experiences for rock blasting in extending existing cutting. The aim of this article is to provide an introduction to bench height, blast holes arrangement, powder charge calculation, and detonating technique during blasting.

Jan 1, 1997