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By Enver Alan, MerkeziYapı

People are migrating because of economic, social, natural and political reasons. These natural and humane factors effects the distribution of populations. The need for tunnels has grown in order to provide a comfortable life and reduce losses such as waste of time, labor, energy, efficiency and so on. It is inevitable to carry out excavations in rock tunnels (shears, platforms, lines, connections, wastewater, distribution, energy, transportation etc.), that will be built by excavating with conventional method, by controlled blasting regarding with constrains. In this study of applied explosives engineering the blasting applications are evaluated, which were carried out for research and development purposes at Yenisahra Station tunnels in Kartal Formation which was built with the aim of solving İstanbul's transportation problem within the framework of the Kadıköy-Kartal Metro Project. Twenty-four shots were made by using explosives in 60 blastholes that were drilled in the tunnel faces, which were located between and outside of two different faults. Six microphones were used to measure the air shock and eight geophones were used to measure the parameter values of the vibrations (particle velocity, frequency, displacement, acceleration, amplitude, wavelength etc.), which were placed at predetermined points of the surface, occurred during the blasting applications. Data from the geophone and microphones were recorded on six seismographs. The coordinates and the distances between the shot points and the measurement stations are determined by an electronic theodolite. The total number of seismic records, recorded in seismographs, is 118. The number of records of vibrations that crossed the faults is 42 and the number of records of vibrations that did not cross the fault is 76. The particle velocity, frequency, amplitude, acceleration, displacement and wavelength were measured in transverse, longitudinal and vertical directions. The total number of measurements is 354. By evaluating all seismic records, the effect of delay intervals, faults and scaled distances on the particle velocity, frequency, amplitude, displacement, acceleration, wavelength and air shock were investigated. When the vibrations formed during the Research & Development (R&D) blasts were examined, it was determined that the parameter values of vibrations that crossed the faults are lower than the ones that did not cross the faults. In addition, when the particle velocity values of all vibrations are examined according to the present circumstances, it is determined that the waves did not cross the fault in all delay intervals are superposed in all directions, and that the least superposing occurred in the 50 ms delay range.

By Dr. Tristan Worsey, Dr. Jhon Silva-Castro

Confinement is an important aspect of blasting. Reducing and increasing confinement can determine whether a blast design performs properly. Over-confined shots usually have poor fragmentation, higher vibrations, and stemming ejection, and unconfined shots usually have a lot of air blast and fly rock. When talking about confinement in blasting, static confinement conditions are typically referenced. Static confinement conditions are ruled by free faces, shot muck, burden, spacing, stemming, hole depth, toe, etc. All these conditions exist in a static state. Static confinement conditions are generally analyzed before the shot takes place, but once the shot starts, the conditions will change according to the sequence and delay of the shot. Once the shot starts, Dynamic confinement takes place. For the authors, Dynamic confinement is the confinement conditions that exist for the charge when it fires and should account not only for the variables included for the static confinement but also for the time and sequence of the shot. The paper explores the theory of dynamic confinement and its role in influencing blast performance. Time and sequence are the main influencers of dynamic confinement and will be the focus of the paper. How to generate the appropriate timing based on blast design, dynamic confinement, static confinement, and geology will also be discussed.

Jan 21, 2025

By Auã Kiahla, Tomi Kouvonen, Vinicius Miranda

Through numerical mathematical processing (Taylor’s approach and numerical derivation) the original data supplied by the accelerometer’s sensors was transformed into velocity and, after the data mining, a statistics residue analysis was applied in order to evaluate if the data from the prototype and from the traditional seismographs were similar. The data from each system was used to estimate the attenuation law and the results are shown in this paper

Feb 1, 2020

By R Tom Watts

The blasting industry has changed more in the last five years than in any period to date. The equipment utilized to load boreholes has changed in response to more precise blasting products and programs, and the need to maintain tighter control over product formulations produced by bulk loading equipment. Tread Corporation has built over 1,300 heavy ANFO type bulk loading units currently operating in over 40 countries worldwide. These units have been designed to meet almost every possible loading scenario but there are always new situations that require special designs and configurations to meet the challenge. The focus of this presentation is to make you aware of the process that should be used to determine the equipment best suited for your application. We will discuss loading cycle times, delivery rates, multiple product mixing capability, capacities, manpower utilization, regulatory compliance, and where and when to use automation in the loading process. We will also discuss the suitability of chassis with regard to ground pressure, turning radius, terrain, weather conditions as well as highway suitability. The US Bridge Law as well as laws that cover the concept of axle loading and spacing will be covered. Through new computer aided design and modular design capabilities, you can now have almost any configuration required to meet your bulk loading objectives. We will also review the range of equipment currently available in the market place and discuss tradeoffs between price, capacity, and complexity.

Jan 1, 2000

By Jeffrey Meissner, Charles Dowding

Cracking is one of the concerns cited by owners of structures adjacent to construction or mine blasting. During the past decade a large number of measurements have documented the low level of crack response produced by typical, ground motions compared to those produced by climatological effects. These data support the observation that there is a level below which ground motions do not cause even cosmetic cracking. As with all new findings, these crack response measurements need to be thoroughly investigated for all possible alternative interpretations. Among these alternatives is that uncracked locations are more affected than cracked locations. This paper presents measurements to shed light on the influence of existing cracks and the response of uncracked, but weak locations. Blast and weather induced responses of cracked and uncracked areas of gypsum wall board are compared in two structures: one near a surface coal mine in Indiana, the other near a limestone quarry in Florida. The ground motions that excited one of the structures were unusual in that the dominant excitation frequencies of 5 Hz were near the structure’s natural frequency and amplitudes exceeded 0.7 ips (18mm/s).

Jan 1, 2011

By John Heilig, Patrick Andrieux

"Near-field monitoring of blast induced seismic vibrations is a practical and useful way of assessing blast field behaviour for diagnosis and optimization purposes. It is also necessary in order to provide the information from which empirical vibration prediction equations, such as the one proposed by Holmberg (11 for example, can be derived. (Strictly speaking, the “near field” extends from the blasthole itself to about one charge length away from it; however, throughout this article, “near field”will.most often refer to the outer limit of this zone, from roughly 0.75 to 1.50 charge length away.) In order to obtain reliable data, proper field monitoring techniques are of paramount importance. Once the data are properly recorded, analysis can be done either in the time domain (describing vibration amplitude vs. time) or in the frequency domain (usually describing vibration amplitude vs. frequency)."

Jan 1, 1995

By Shi Hongchao, Zou Zou Xinkuan, Zhang Jichun

As drilling and blasting is carried out in an urban tunnel, which is adjacent to an existing building or structure, the balance between blasting-induced vibration reduction and drivage efficiency is a most important issue that must be resolved properly. Therefore, a new cut blast method named Stepped V-cut millisecond blasting (SV-cut) was developed by optimizing the most common used Vertical V-cut blasting method (V-cut). The most significant features of SV-cut lie in the utilization of sublevel interval charging structure and millisecond delay blasting technology in cut hole and the cut-cavity formed from outside to inside sequentially. SV-cut provides advantages of high borehole using ratio, low vibration level, and satisfied advance per attack. Based on the principal of millisecond blasting, the rock fragmentation process and the vibration reduction mechanism of SV-cut are analyzed. Determining methods of blasting parameters, which do have significant effect on vibration intensity and cut-cavity formed quality, are proposed according to the forming requirement of both outer and inner cut-cavity and vibration reduction. In order to compare the performance between SV-cut and V-cut, field blasting experiments were performed in the blasting engineering of Yamalike twin-arc tunnel, which closely passes over aged parallel tunnels. Blasting results show that SV-cut blasting is proven as an effective tunnel blasting method for both increasing blasting effects and decreasing blasting vibration. Comparing SV-cut with V-cut, the SV-cut can increase blasting drivage about 8.5% and reduce the vibration intensity induced by cut hole blasting 30% at least.

Jan 1, 2015

By Gene Baker

A new Safety Library Publication (SLP), SLP-27, which is titled “Security in Manufacturing, Transportation, Storage and Use of Commercial Explosives” was recently released by the Institute of Makers of Explosives (IME). SLP-27 makes recommendations for both general security and enhanced security at explosives sites when security risk levels, declared by the Department of Homeland Security (DHS) using its Advisory System, have temporarily increased.

Jan 1, 2006

By Pr-Anders Persson

This chapter deals with the concepts of shock waves and detonation waves together, because a detonation wave is really a shock wave, supported by the explosive reaction that the shock wave ignites and propagates as it travels through the explosive material. In the c.ootext of rock blasting, furthermore, there is justification for treating shock waves and detonation waves together, because the mechanical effect of the detonation in an explosive in a drillhole in rock is propagated and its effects are spread throughout the surrounding rock by means of a shock wave. The overall performance of sn explosive in rock blasting or any other application is of course dependent on how much thermal energy is released in the chemical reaction that occurs when the material detonates, and on how much useful mechanical work the reaction products can do as they expand. A major portion of this chapter deals with the prediction and measurement of explosive performance, a subject which is now still in a process of rapid development.

Jan 1, 1995

By Benjamin Cebrian

Wall control blasting is an expensive and labor intensive operation. Obtaining a good design is a first step that is not enough to ensure desired results. Experience shows that designs are not always well implemented, not only in the contour blast itself, but also in surrounding production blasts that can affect the final pit wall. In this paper techniques and reference indicators are described in order to audit and evaluate if correct implementation of designs have been done.

Jan 1, 2013

By Phillip R. Mulligan, Kevin Gantz, Aaron J. Ward, allen shirley, Sean Treadway

Understanding the impulse transferred into a structure by the coupled two-phase loading produced by an explosive charge buried in soil is of interest for various applications. The most common impulse measurement technique involves a buried explosive charge and a steel plate/test structure suspended above the charge. Upon detonation of the charge, the soil and overpressure heave the plate into the air. The plate’s trajectory and velocity provide the necessary information to calculate the total impulse transferred from the charge configuration.

Jan 1, 2016

By Thierry Bernard, Phillipe Cappello, Jean Marc Laboz

"The main reasons of the emergence of electronic detonators are linked to:-Local urban development close to mining operation sites-Environment regulations"

Jan 1, 1995

By BernardThierry

To be able to precisely predict the result of a mine blast before pressing the button is a goal for many blasters due to the environmental and economic constraints of our century. Based on the fundamental fracturing of the mechanism of rocks by explosives, the most recent research in digital modeling, the power of present computers, and the possibilities offered by drones, we have designed a realistic digital 3D simulation model for mine blasts. This new type of model enables us to concurrently simulate the fragmentation of the rock, its movement and the associated seismic levels, all within a few minutes, which is a time compatible with a production cycle. Due to the complexity of the model, this article reveals the main principles and compares the results of simulations with on-site measurements in various sectors, i.e. quarries, mines and tunnels.

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 R J. Johnson

The development of "SANFO" has provided the Mining Industry with a LOW COST HIGH GAS VOLUME, VARIABLE DENSITY, Blasting Agent which can be blended "On Site" in a simple Agitator mixing and charging system by mine site employees.

Jan 1, 1996

By Neal Lee, Braden T. Lusk, Brendan McCray

Determining the minimum amount of inert material that can be used between explosive columns is a complex problem. Using too little inert material can result in detonator/primer failure, either by sympathetic detonation of or failure to fire of the subsequent explosive column(s). Propagation type failure results when inert material length between charges is small enough that the subsequent (delayed) deck fires more or less instantly. In this situation, the primer, detonator, or bulk product is initiated by the shock wave from the earlier firing deck. This type of failure may be un-noticed until the vibration/airblast report is examined.

Jan 1, 2016

By Brandon Fryman, Josh Hoffman, Rhys Baker

A post-detonation debris collection project was led in conjunction with a large ammonium nitrate (AN) railcar detonation conducted by the Department of Homeland Security-Transportation Security Administration, Department of Defense-Combating Terrorism Technical Support Office, Sandia National Laboratories, and the U.S. Army Dugway Proving Grounds. This important work will aid in underpinning algorithms used in a Quantitative Risk Assessment (QRA) tool.

Feb 1, 2020

By Pefer F. Stacey

This paper considers some of the trends in slope design technology that are emerging as we approach the 21st Century. While the ability to design stable slopes has unproved greatly over the past 20 years, trends towards steep short-term slopes for small highgrade orebodies, and very high slopes for mega-pits centered on low grade deposits are starting to indicate limitations in available technology.

Jan 1, 1994

To meet the energy requirements, hydroelectric projects are planned and executed in many countries. Though these projects requires a high capital investment, the returns are regular with minimum maintenance after commissioning of the project and are ecofriendly. Bhutan is situated in the eastern Himalayas and covers an area of 38,394km2 (14824.01sq. miles. It is bordered by India in East, South and West and by Tibet in the North. The hydropower potential of the country is estimated at 30,000MW, out of which around 5% has been harnessed.

Jan 1, 2016

By R. F. Favreau, Patrice Favreau

"A blast with explosives creates vibration waves in the zone around the blast.The prediction of the intensity of vibrations is important because people in the cinity demand that the vibrations do not disturb them, and society imposes limits on the vibrations. The U. S. Bureau of Mines (USBM) showed that the easurement of the particle velocity U predicts the risk of damage from vibrations. A currentapproach of blasters to monitor vibrations is to measure them with a seismograph at several distances S, and create a graph of U vs. S and the explosive charge “W” according to the equation U = K / (S / W)N where K and N are constants that depend on the blast method and the nature of the ground over the distance S. Though useful, this equation is empirical, and the results predicted from it are very variable, as shown by figure 1 which indicates that a prediction of U can deviate significantly from the actual value. Moreover, a minimum of two seismograph measurements at two values of S are required to establish the curve. However, here now exists another very convenient method to predict U; it is with the simulator Vibmas, which is based on the fundamental principles of how a blast reates vibrations. This simulator takes into account not only W but rather all the blast parameters, the type of explosive and the properties of the rock. Moreover, to establish the calculation of U as a function of S, only one seismograph measurement is required rather than two as for the USBM method. This last difference is important because it makes it easy to predict U not only as a function of S, but also as a function of the orientation of S. On the site this allows much safer control of the vibrations, and the use of larger explosive charges which reduce excavation costs. The article presents results from a field case at a hydroelectric project in Canada, where the deviation was very moderate. Use of this vibration simulator on the Web is very easy."

Jan 1, 2015