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Full-Text Articles in Engineering

The Effect Of Delay And Sequence On Blasting Fragmentation Results, Tristan Worsey Jan 2020

The Effect Of Delay And Sequence On Blasting Fragmentation Results, Tristan Worsey

Theses and Dissertations--Mining Engineering

Blasters use the delay between charges and the firing sequence of the explosive charges to help reduce vibrations and achieve the desired fragmentation. Although delay and sequence are recognized as very important for vibrations and fragmentation, only vibration models consider timing as a variable in the prediction tool, without any known model for fragmentation prediction based on the delay sequence. Of the few fragmentation models available, very few take delay into account and do not give guidance on row delay and/or sequence selections. With the invention of electronic detonators in 1984, there are new avenues to explore with sequence ...


Seepage-Coupled Finite Element Analysis Of Stress Driven Rock Slope Failures For Bothnatural And Induced Failures, Thomas Becket Anyintuo Mar 2019

Seepage-Coupled Finite Element Analysis Of Stress Driven Rock Slope Failures For Bothnatural And Induced Failures, Thomas Becket Anyintuo

Graduate Theses and Dissertations

Rock slope failures leading to rock falls and rock slides are caused by a multitude of factors, including seismic activity, weathering, frost wedging, groundwater and thermal stressing. Although these causes are generally attributed as separate causes, some of them will often act together to cause rock slope failures. In this work, two of the above factors, seepage of water through cracks and crack propagation due to the after effects of blasting are considered. Their combined impact on the development of rock falls and rock slides is modeled on ANSYS workbench using the Bingham Canyon mine slope failure of 2013 as ...


A New Shock-Wave Test Apparatus For Liquid Co2 Blasting And Measurement Analysis, Ying Chen, Hongwei Zhang, Zhijie Zhu, Ting X. Ren, Chen Cao, Feng Zhu, Yunpeng Li Jan 2019

A New Shock-Wave Test Apparatus For Liquid Co2 Blasting And Measurement Analysis, Ying Chen, Hongwei Zhang, Zhijie Zhu, Ting X. Ren, Chen Cao, Feng Zhu, Yunpeng Li

Faculty of Engineering and Information Sciences - Papers: Part B

Liquid CO 2 blasting of coal or rock body technology is widely used for improving permeability, pressure relief, cutting proof, and roadway development. Due to the lack of proper apparatus for blasting measurement, the determination of blasting parameters is often not under scientific basis. A newly designed experimental apparatus is developed to monitor shock-wave pressure of liquid CO 2 blasting. The apparatus mainly consists of testing tube and base bracket. The testing tube is fixed on the base bracket by fixed ring. The base bracket is fixed to the ground by expansion bolts to ensure the stability of the apparatus ...


Understanding The Connection Between Blasting And Highwall Stability, Robert Quentin Eades, Kyle A. Perry Jan 2019

Understanding The Connection Between Blasting And Highwall Stability, Robert Quentin Eades, Kyle A. Perry

Mining Engineering Faculty Research & Creative Works

Surface mines continue to implement highwalls for several reasons, such as increasing recovery, improving margins, and justifying higher stripping ratios. Highwall stability is a complex issue that is dependent upon a variety of mining and geologic factors, and a safe design is necessary for a successful surface operation. To improve highwall stability, it is important to understand the connection between local geology and blasting. Explosives are employed throughout the mining industry for primary rock breakage. There are a number of controlled blasting techniques that can be implemented to improve highwall stability. These include line drilling, smooth wall blasting, trim blasting ...


The Mechanics Of Precision Presplitting, Anthony Joseph Konya Jan 2019

The Mechanics Of Precision Presplitting, Anthony Joseph Konya

Doctoral Dissertations

"Precision Presplitting is a widely used method of presplit blasting for the mining and construction industries. In recent years considerable effort has gone into the development of empirical equations based on field data to be able to better design the Precision Presplit for various rock types and structural environments. However, the most widely discussed theory about the mechanics of the presplit formation, that of shockwave collisions, does not appear to be applicable for this method of presplitting.

This research has disproven this theory based on insufficient magnitude of the shockwave from modeling with basic wave mechanics. Other authors have suggested ...


Investigating Blast Fume Propagation, Concentration And Clearance In Underground Mines Using Computational Fluid Dynamics (Cfd), Raymond Ninnang Tiile Jan 2019

Investigating Blast Fume Propagation, Concentration And Clearance In Underground Mines Using Computational Fluid Dynamics (Cfd), Raymond Ninnang Tiile

Doctoral Dissertations

"Blasting activities using standard industry explosives is an essential component of underground hard rock mining operations. Blasting operations result in the release of noxious gases, presenting both safety and productivity threats. Overestimation of post-blast re-entry time results in production losses, while underestimation leads to injuries and fatalities. Research shows that most underground mines simply standardize post-blast re-entry times based on experiences and observations. Few underground mines use theoretical methods for calculating post-blast re-entry time. These theoretical methods, however, are unable to account for the variations in the blasting conditions. Literature review shows that: (i) there is currently no means of ...


Optimization Of Drilling And Blasting Practices At A Western Us Open Pit Copper Mine, Joel Gadikor Apr 2018

Optimization Of Drilling And Blasting Practices At A Western Us Open Pit Copper Mine, Joel Gadikor

Graduate Theses & Non-Theses

The mining process begins with drilling and blasting activities. The efficiency of blasting affects all downstream operations such as loading, hauling, crushing and milling. Therefore drilling and blasting activities should be designed to ensure that designed parameters produce the desired fragmentation. The Kuz-Ram model is a fragmentation prediction model and is widely used for predicting the fragmentation distribution from blasting in the mining industry. This research evaluates the performance of the Kuz-Ram and Modified Kuz-Ram models to determine the most accurate models applicable to a Western US open pit copper mine’s fragmentation data. The performance assessment was done using ...


The Effects Of Underground Blasting On Nearby Pre-Existing Structures, Logan Connolly Apr 2018

The Effects Of Underground Blasting On Nearby Pre-Existing Structures, Logan Connolly

Graduate Theses & Non-Theses

Butte, Montana holds a prestigious place in the history of mining, deemed “The Richest Hill on Earth,” containing a plethora of underground mines. The Orphan Boy/Orphan Girl underground mines, on the western side of Butte, operated from 1895-1956 producing zinc, lead, silver, and manganese. Today, the Orphan Boy mine is part of Montana Tech’s Underground Mine Education Center (UMEC) and the Orphan Girl mine houses the World Museum of Mining. Underground development in the Orphan Boy mine continues to progress as students from Montana Tech receive hands-on underground training; in addition, the UMEC is a multi-disciplinary research facility ...


Determine The Potential Drill Utilization Improvements And Rock Fragmentation Requirements Using Directional Drilling In A Coal Mining Overburden Highwall Application, K. D. Dill, S. D. Rosenthal Feb 2017

Determine The Potential Drill Utilization Improvements And Rock Fragmentation Requirements Using Directional Drilling In A Coal Mining Overburden Highwall Application, K. D. Dill, S. D. Rosenthal

Mining Engineering

This project analyzed the efficiency of incorporating the use of directional drilling technology into coal overburden blasting. Directional drilling is currently in use in the petroleum industry and it is believed that it will be a valuable asset in the mining industry. This project has shown that directional drilling can be a viable technology for use in the coal overburden removal process resulting in increased drill utilization and potential for cost savings. Future work regarding blasting and geotechnical evaluation should be performed to solidify the concept.


The Influence Of Caprock On Blast Fragmentation Distribution, Matthew Kurtis Coy Jan 2017

The Influence Of Caprock On Blast Fragmentation Distribution, Matthew Kurtis Coy

Doctoral Dissertations

"This dissertation describes the development of a small-scale model of a caprock-laden quarry blast and discusses the results from that testing. The purpose of this testing was to provide insight into the reasons for poor caprock breakage during blasting.

Small-scale test blocks were poured using a weak mortar mix to represent a limestone formation at a small scale. A cold joint was created in the upper portion of the test specimens to represent the bedding plane that separates caprock and substrate layers in a caprock-laden limestone bench. The scale-model test blocks were blasted using detonating cord. The primary configuration for ...


Pore Pressure Measurement Instrumentation Response To Blasting, Kylie M. Larson-Robl Jan 2016

Pore Pressure Measurement Instrumentation Response To Blasting, Kylie M. Larson-Robl

Theses and Dissertations--Mining Engineering

Coal mine impoundment failures have been well documented to occur due to an increase in excess pore pressure from sustained monotonic loads. Very few failures have ever occurred from dynamic loading events, such as earthquakes, and research has been done regarding the stability of these impoundment structures under such natural seismic loading events. To date no failures or damage have been reported from dynamic loading events caused by near-by production blasting, however little research has been done considering these conditions. Taking into account that current environmental restrictions oblige to increase the capacity of coal impoundments, thus increasing the hazard of ...


Impact Mechanics And High-Energy Absorbing Materials: Review, Pizhong Qiao, Mijia Yang, Florin Bobaru Jul 2013

Impact Mechanics And High-Energy Absorbing Materials: Review, Pizhong Qiao, Mijia Yang, Florin Bobaru

Florin Bobaru Ph.D.

In this paper a review of impact mechanics and high-energy absorbing materials is presented. We review different theoretical models (rigid-body dynamics, elastic, shock, and plastic wave propagation, and nonclassical or nonlocal models. and computational methods (finite-element, finite-difference, and mesh-free methods. used in impact mechanics. Some recent developments in numerical simulation of impact (e.g., peridynamics) and new design concepts proposed as high energy absorbing materials (lattice and truss structures, hybrid sandwich composites, metal foams, magnetorheological fluids, porous shape memory alloys. are discussed. Recent studies on experimental evaluation and constitutive modeling of strain rate-dependent polymer matrix composites are also presented. Impact ...


Impact Mechanics And High-Energy Absorbing Materials: Review, Pizhong Qiao, Mijia Yang, Florin Bobaru Oct 2008

Impact Mechanics And High-Energy Absorbing Materials: Review, Pizhong Qiao, Mijia Yang, Florin Bobaru

Faculty Publications from the Department of Engineering Mechanics

In this paper a review of impact mechanics and high-energy absorbing materials is presented. We review different theoretical models (rigid-body dynamics, elastic, shock, and plastic wave propagation, and nonclassical or nonlocal models. and computational methods (finite-element, finite-difference, and mesh-free methods. used in impact mechanics. Some recent developments in numerical simulation of impact (e.g., peridynamics) and new design concepts proposed as high energy absorbing materials (lattice and truss structures, hybrid sandwich composites, metal foams, magnetorheological fluids, porous shape memory alloys. are discussed. Recent studies on experimental evaluation and constitutive modeling of strain rate-dependent polymer matrix composites are also presented. Impact ...


Calibration Of Optical Digital Fragmentation Measuring Systems, Norbert H. Maerz, Wei Zhou Jun 2000

Calibration Of Optical Digital Fragmentation Measuring Systems, Norbert H. Maerz, Wei Zhou

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Optical granulometry systems like WipFrag are required to measure fragments in situ. That is to say, the fragments are in piles where sorting takes place, where fragments are partially overlapped, and where fines may not be seen because they fall in and behind the coarser fragments, or where the fines are simply too small to be seen. As a result, optical systems tend typically to overestimate the size of the distribution, and underestimate the variability of the distribution. The wider the size distribution being measured, the more severe the problem is. This paper presents the results of a study that ...


Optical Digital Fragmentation Measuring Systems -- Inherent Sources Of Error, Norbert H. Maerz, Wei Zhou Jan 1998

Optical Digital Fragmentation Measuring Systems -- Inherent Sources Of Error, Norbert H. Maerz, Wei Zhou

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Automated optical imaging systems of measuring fragmentation are increasingly being used in the mining, comminution, and materials handling industries. These methods have been well received in many of the industries involved. Considering that in many of these applications there are no alternative ways of sizing material, having even a rudimentary measurement of size distributions allows evaluations of explosive, blast design, detonator performance, crusher and milling performance, and material degradation due to transport.

Optical methods have inherent limitations, which reflect on accuracy, precision, and reproducibility of measurement results. This stems from the fact that there are myriads of variables, which affect ...


Open Pit Mining Operations, James A. Simon May 1957

Open Pit Mining Operations, James A. Simon

Bachelors Theses and Reports, 1928 - 1970

This report on open pit mining operations will discuss: the history of open pit mining, factors important in the selection of open pit mining and in the development of an open pit, and the various mining and operational methods used in this type of an operation. Stripping coal mining operations will be discussed but the majority of the report will be on open pit metal mines.