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By Selamawit Asfaw, Mohamad Sharif

In recent years, the use of modal analysis has increased to include many different aspects of the construction industry. Computer modal analysis can be used in determining the dynamic properties of a structure by mathematical equations and knowledge of the structure’s physical properties. This technique can now be used to predict the level of vibration induced by blasting on adjacent structures. Ground vibration induced by buried explosives is a major concern for contractors when excavating near utility pipelines such as gas and water lines. The size limitations placed on easements causes the necessity of additional utility lines to be placed in close proximity to existing lines. Through the development of computer models of the pipe, stress analysis can be performed prior to blasting. Based on the calculated dynamic properties (natural frequencies and modal shapes) and the maximum allowable displacements and stress levels (which are established by the pipe manufacturer) the allowable maximum charge weight per delay can be selected for the blast. The selected maximum charge weight per delay will ensure that the resulting pipe peak particle velocity level is within 95% confidence. This means, statistically, there exists a 95% probability that the actual pipe peak particle velocity would be less than the predicted value. The pipe is then instrumented with vibration measuring sensors to ensure that vibration levels are within the allowable maximum pipe strength. In conclusion, this technique can assist the engineers and blasters, to establish the proper blast design. It allows for safe and efficient installation of additional utility lines adjacent to existing lines. This technique can also be applied to predict the structural response to blasting induced vibration for a variety of complex structures. A detailed explanation of this technique, as well as an example of application including formulas used for this technique will be provided in this paper.

Jan 1, 2000

By Lawson J. Taylor, Paul N. Worsey

Recent reputable evidence conclusively indicates that conventional chemical delay elements in delay detonators are notoriously inaccurate and can thus seriously affect blasting efficiency.

Jan 1, 1983

By Chris Breeds, Larry Leone, Jerry Wallace

One of the Authors was recently retained to provide a professional engineering analysis of the potential impacts from underwater blasts used to enlarge intake tunnels at the Cheesman Dam near Denver in Colorado and to design Blast Protection Bags that could be installed in each tunnel to protect the 100- year old downstream valve structures.

Jan 1, 2012

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 Tom Watts

This paper will focus on the design, manufacture and use of pump safety systems on MMUs (Mobile Manufacturing Units – Bulk Trucks) with progressive cavity pumps. The practice of pumping bulk blasting agents is highly regulated and the explosives manufactures have done an excellent job of hazard and operability studies allowing criteria to be established for the safe pumping.

Jan 1, 2009

"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 Joshua Hoffman, Braden Lusk, David McLane, John Rathbun

The research conducted previously on Shock-Tunnel Waveform Analysis gave a brief insight into the propagation of a shockwave within a shock-tunnel compared to that of an open air arena test. As a refresher, a shock-tunnel is an energy channeling device used to simulate the effects of a large scale detonation with significantly smaller charge weights; having the ability to conduct tests in this fashion can greatly reduce the costs of testing products.

Jan 1, 2012

By Tamara Wiseman, David Stewart

"A Quarry located in Georgia is a green-field site established in 2011. The quarry lies in the eastern part of the Georgia Piedmont area. It is within a distinctive, northeast-trending belt of relatively high-rank metamorphic rocks known as the Kiokee Belt, a poorly mapped sequence of units that largely consists ofamphibolite and various schists and gneiss that are host for relatively young granite bodies andassociated pegmatite and aplite dikes."

Jan 1, 2017

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 Paul N. Worsey

Disturbed zones of rock have been measured for blasted highway rock cuttings by Matheson and Swindells of the Transport and Road Research Laboratory (TRRL) of Great Britain. These zones have been shown to be directly attributable to the blasting process and accordingly vary in depth depending on blasting technique. Perimeter blasting such as smoothwalling and pre-splitting has been shown to be effective in reducing the depth of disturbed rock. Although extensive work has been carried out on surface excavations for medium diameter (l00mm) blast holes, none has been undertaken for underground excavations.

Jan 1, 1985

By L. L. Oriard

he Metropolitan Water District of Southern California (MWD) supplies water to some 16 million people in a semi-arid region. Most of this water is imported. Some of the supply lines cross over the San Andreas fault, one of the most notorious and active faults in the U.S. There was a serious need for emergency water in case normal supplies should be interrupted. To fill that need, MWD had to find a reservoir site on the west side of the San Andreas fault, west of the mountains. Because of the distinctive nature of the location, it was necessary to construct a huge “bath tub” by building a dam at each end of a valley, requiring some 115 million cubic yards (88 million cu.m) of fill. In effect, two large-scale surface mining operations have been under way simultaneously. The $2.2 billion project is known as the Eastside Reservoir Project. Because of space limitations, this paper will be limited to those topics which are expected to be of primary interest to explosives engineers, principally related to large-scale rock fill production. There is not sufficient space to discuss the many diverse geotechnical questions related to site selection, geological and geophysical field testing, laboratory testing and design considerations. This brief overview may assist those who might be interested in making a tour of the project site following the ISEE conference.

Jan 1, 2000

By Carlyle F. Bunn

The source of the standards adopted by the Occupational Safety and Health Administration are outlined. Preplanning to eliminate violation of the standards and improve overall job efficiency are discussed.

Jan 1, 1975

By L D. Lawrence, R S. Day, Gordon Coleman

Commercial emulsion explosives are typically characterized by their relatively high detonation velocities due to the intimacy of oxidizer and fuel and to their sensitization with glass microballoons. However, numerous blasting operations in softer, more porous rock formations are better fragmented with slower shooting explosives. Although mixtures of emulsions with large amounts of ANFO (60-80%) can considerably reduce the high velocities, little water resistance is achieved with low levels of emulsion blended with ANFO. "Water proof" blends containing typically 50 percent of emulsion become quite costly due to escalating powder factors in ANFO patterns. Blends of sensitized emulsions with 20-30 percent ANFO retain the high velocity characteristics of the emulsions as well as increased densities which can also adversely affect blasting results in softer rock formations. The introduction of a reliable and predictable on-site gassing process for sensitization and density control of repumpable emulsions, with or without added ANFO, offers the end user the option of supplying a final product more suited to his blasting needs. The capability to widely vary final product loading densities and consequently product detonation rates better tailors the final explosive to different rock characteristics. The beneficial advantages of this system in softer rock formations have been well documented. Overall comparison between these variable density products with typical repump emulsions containing solid density control will be reviewed. Besides the obvious cost advantages and safety advantages of these systems the end user is provided more definitive control of his blasting operation.

Jan 1, 1990

By Lawrence Mirabelli, Wayne Lidkea, Mario Paventi

On Januarv 1, 1996, INCO Limited, Tamrock OY, Dyno Nobel and CANMET formed a consortium for the development of robotic mining equipment called the Mining Automation Program (MAP). This project was a tive- [5] year research and development program that combined the talents of the above organizations to facilitate the development of mining equipment and systems for tele-remote mining. The year 2000 brings MAP to conclusion with actual production process trial testing of the developed prototype equipment and systems during the period between May and October. MAP consisted of multiple projects all of which are based on the communication system developed by INCO Mines Research and currently sold and marketed by Automated Mining Systems Limited. The main projects include the development of a positioning and navigation module (including a software mapping system that will be inherent to each piece of equipment), robotic systems for underground development and stoping operations, as well as software systems to support the use of this equipment. Included in the program was the establishment of a Research Mine, at INCO’s 175 orebody, Copper Cliff, Ontario, Canada. This facility allowed for the on-site collaboration between the companies and research organization in the design and testing of techniques and equipment to mine with TeleminingTM. Some of the prototype equipment developed through the program are: a tele-operated drilling jumbo, a tele-operated load-haul-and-dump [LHD] tram, a tele-operated production drill, a remote initiation system for programming and detonation of electronic detonators, and the development of a vatiable energy bulk emulsion explosive system, including loading equipment, to deliver the explosives to boreholes. Use of tele-operated and automated equipment for mining mandates a dramatic change in the traditional drill/blast/muck/support cycles in the underground mining process.

Jan 1, 2001

By R M. Bhatawdekar, A I. Theresraj, H S. Venkatesh

Wadi Limestone Quarry is one of the largest captive mines of Associated Cement Companies Ltd, India. The mine management wanted to extend the excavation as close to the plant as possible for maximum exploitation of the deposit. The National Institute of Rock Mechanics and the management of Wadi Limestone Quarry carried out comprehensive investigations to evolve a methodology to control vibration and flyrock within safe limits.

Jan 1, 1999

By Kenneth Faroni, Catherine Aimone-Martin, Thomas Gelormino

A blasting improvement program began in 1985 at two traprock quarries in Connecticut to reduce the levels of ground motions and airblast measured at residential structures surrounding the operations. The quarries are situated within town limits, adjacent to a number of historical and other structures. Although blasting vibration amplitudes were found to be far below those that could produce cosmetic defects in structures, they were perceived to be the cause of structural defects observed by homeowners. Based on a comprehensive * review of blasting practices in place during1985, an extensive vibration monitoring program was implemented. The initial study included the instrumentation of selected residential structures to record and analyze strains imposed within structures from quarry blasting, environmental changes, and from daily household activities. A comparison of the results was made with the results reported by the U.S. Bureau of Mines in 1980. The highest strain imposed in drywall from blasting (13 J_I strain) was 12% and 1% of the highest strain levels recorded for normal household activities and temperature changes, respectively. The present philosophy in production blasting is to attempt to keep vibration amplitudes as low as practical by implementing state-of-art blasting control techniques. Currently, blasting seismographs are placed in a circular manner around each quarry, providing production blast vibration records for 360 degrees of coverage at distances of 2500 to 4000 ft. from blasting operations. Seismograph and production blast records are analyzed each year and become part of a Blasting Improvement Plan submitted to the local zoning commission as part of the annual operating permit process. This paper summarizes the results of previous vibration monitoring programs and outlines the modifications made to blasting practices to minimize the levels of ground motions and airblasts. The public relations efforts and standard corporate procedures used by company personnel to address all blast related complaints and alleged damage claims since 1985 are also discussed.

Jan 1, 2000

By Justus Deen, Paul Sterk

Overbreak into the wall rock of a development drift leads to the inevitable need to rehabilitate a drift. Moreover, overbreak in a production heading can lead to external dilution and lower ore grades. Both of these factors are critical to bottom line costs of underground operations today. The geology of the Homestake orebody makes this an even more complex problem. For over fifteen years the Homestake Mine has attempted to implement perimeter blasting techniques that are both safe and cost effective. Many practical perimeter methods and products have been tested including air decking; low density emulsions; various types of stick powder; various decoupling media including rope, low density ANFO, polystyrene ANFO, salt based ANFO, and various grain detonating cords up to 200 grain.

Jan 1, 1997

By Dennis Dobson, Keith M. Henderson

Lone Star Industries, Inc. in Cape Girardeau, Missouri operates an open pit mine to produce limestone for its portland cement manufacturing plant. The present mining method, for safety and legal reasons, requires a set back from the property line, a berm, sloped overburden, and vertical rock walls with catch benches.

Jan 1, 1997

By David Leidel, James Stuart

The 50 ohm resistorized electric detonator is commonly used in the oilfield for initiation of wireline conveyed perforating guns and other downhole explosive tools. This type of electric detonator provides some degree of safety above that of the conventional one ohm electric detonator, since a higher current level is required to initiate the device. In order to obtain the necessary data to develop safe distance tables from RF sources for the 50 ohm electric detonator, laboratory tests were conducted to determine the detonator’s “no-fire” current, AC impedance, and its susceptibility to ESD. The results were surprising as two types of failure modes were observed. The “no-fire’ current levels determined from Langlie “One-Shot” Test Methods were determined for the devices tested providing values for the 0.999 probability “no-fire” power level at a 95% confidence level. This data will serve as the basis for sets of safe distance tables from RF sources that will appear in the forthcoming edition of the Institute of Makers of Explosives Safety Library Publication 20, “Safety Guide for the Prevention of Radio Frequency Radiation Hazards in the Use of Commercial Electric Detonators, (Blasting Caps)”.

Jan 1, 2010

By Blenda Lopes, Rodolfo Matias, Vagner Paixão, Vinicius Leão VALE, Edivarde Sousa

Seismography is an extremely important subject in the context of rock blasting, especially in the current scenario, which involves the need for increased controls due to the growth of urban areas near open-pit mining operations. Worldwide, communities are becoming increasingly aware of the environmental and social impacts associated with mining activities. Therefore, maintaining good relationships with these stakeholders is essential to preserve the social license to operate and to comply with current legislation. This situation is exemplified in an open-pit iron mine near the capital of Minas Gerais, Brazil, where the community is located less than 40 meters from the pit boundaries. Blasting activities within the mining area occur at distances less than 500 meters from the nearest community, making continuous seismograph monitoring necessary to ensure that operational conditions are maintained without compromising exploitation efficiency. The threshold for peak particle velocity, according to Brazilian Standard 9653:2018 by ABNT, is 15 mm/s at frequencies around 4 Hz. However, even though the peak particle velocity commonly registered was inferior to 3 mm/s, there were still complaints from nearby residents regarding human discomfort. To further reduce vibration levels, a study was conducted to implement a new blast design, considering factors such as reducing bench height, altering the hole delays, maintaining the maximum charge per delay, and adjusting the drilling pattern without negatively affecting rock fragmentation quality. Following the implementation of the revised blasting parameters, seismographic measurements in the region decreased to below 0.6 mm/s. This significant reduction in ground vibrations contributed to minimizing community disturbances and fostering a more positive relationship between the company and its surrounding residents.

Jan 26, 2026