Explosives Engineering Commons^™

The Dynamic Material Response Of Csa Cement Using A Split Hopkinson Bar, Elliott L. Morgan

Theses and Dissertations--Mining Engineering

The University of Kentucky Center for Applied Energy Research (CAER) Cementitious Materials Group is developing a pourable Calcium Sulphoaluminate (CSA) cement-based concrete for rapid repair applications. Due to dynamic events like vehicle strikes, ballistic events, or other dynamic loading events, the dynamic material characteristics are important for understanding how the material will respond. A large diameter Split Hopkinson Pressure Bar (SHPB) was used to test samples of the pourable CSA cement and determine its dynamic material properties in the early strength development phase. 24 samples were tested in 7 day intervals for 28 days. Samples were prepared targeting a length …

Underground Blast Fragmentation Modeling For Use In The Mine-To-Mill Strategy, Lauren Shields

Theses and Dissertations--Mining Engineering

More than 40 years ago, the mine-to-mill concept was introduced in the mining industry by establishing a relationship or link between processing and mining activities. To date, many successful case studies have documented the evident benefits of the mine-to-mill approach. In most cases, the basis of the mine-to-mill approach is to tailor the details of a blast design and its proper execution in order to satisfy specific mineral processing requirements downstream. Most of the available literature and case studies deal with surface mine operations. Due to the relative simplicity of surface mining, the relationship between the powder factor, defined as …

Discrete Element Modeling To Predict Muckpile Profiles From Cast Blasting, Russell Lamont

Theses and Dissertations--Mining Engineering

Movement of overburden or ore from one location to another may be considered the primary physical process of mining. The means by which it is transported is then of primary concern both to economic production and cost control. The geologic characteristics of some mineral deposits, especially coal and phosphates, lend themselves to overburden transport by means of cast blasting, which when efficiently designed has proven itself to be a cheaper method than traditional truck/shovel, dragline, or even dozer push transport. Simultaneously, this movement of a significant portion of overburden using explosives may enable an operation to increase mineral production, as …

Prediction Of Blast-Induced Ground Vibrations: A Comparison Between Empirical And Artificial-Neural-Network Approaches, Luis F. Velasquez

Theses and Dissertations--Mining Engineering

Ground vibrations are a critical factor in the rock blasting process. The instantaneous load application exerted by the gas pressure during the detonation process acts on the blasthole walls creating dynamic stresses in the adjacent rock. This triggers different sorts of stress waves, mainly divided into two categories: body and surface waves. The first comprises the P and the S waves, while the second comprises Rayleigh waves. These waves spread concentrically starting at the blast location and move along the ground surface and its interior, being attenuated as they reach further distances.

In most cases, and accepting the hypothesis that …

Predicting Fracture Extension Around A Borehole Using The Numerical Displacement Discontinuity Method, Nathaniel Schaefer

Theses and Dissertations--Mining Engineering

Prediction of blast damage radius is integral in the optimization of mining safety and production. The damage radius can be related to blasting variables such as fragmentation size as well as overbreak in hard rock. Various methods have been developed to predict and assess damage radius extension for individual holes to aid in blast design. These methods range from experimental and observational techniques to theoretical applications. Some of these methods have been used with a degree of success. However, many of them lack a comprehensive combination of experimental and theoretical contributions. Since post-blast environments are not conducive to assessing whether …

Proof Of Concept For The Development Of A Ground Vibration Sensor System For Future Research In Blasting, John Meuth

Theses and Dissertations--Mining Engineering

Ground vibrations from blasting are one of the leading limitations to mining (underground and surface). There is a need for a low-cost scalable vibration monitoring system to conduct large scale ground vibration projects in the mining industry. Studies conducted on ground vibrations use any number of different sensors to obtain their data, the different sensor capabilities and methods for data processing lead to uncertainties in the research and regulations set for ground vibrations. Commercial Systems do not allow researchers to obtain raw output data, and the data processing procedures are not provided or disclosed for these systems. In order to …

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 and …

Simplifying Techniques Applied To Computational Fluid Dynamics Modeling Of Methane Explosions, Laura Steeves

Theses and Dissertations--Mining Engineering

Traditional methods of studying underground coal mine explosions are limited to observations and data collected during experimental explosions. These experiments are expensive, time-consuming, and require major facilities, such as the Lake Lynn Experimental Mine. The development of computational fluid dynamics (CFD) modeling of explosions can help minimize the need for large-scale testing. This thesis utilized the commercial CFD software, SC/Tetra, to examine three case studies. The first case study modeled the combustion of methane in a scaled shock tube, measuring approximately 1 foot by 1 foot, by 20.5 feet long, with a methane cloud of 2.5 feet in length, at …

Analysis Of Underground Coal Mine Structures Subjected To Dynamic Events, Brooklynn Yonts

Theses and Dissertations--Mining Engineering

Underground coal mine explosions pose a significant threat to infrastructure such as mine seals and refuge alternative chambers. After a mine seal failed in the Sago mine disaster, which took the life of 12 miners, design requirements were reexamined and improved. However, most research being completed on the analysis of mine structures during an explosive event focuses solely on peak pressure values, while ignoring the impact of pressure duration. This study investigates the impact pressure duration, waveform shape, and impulse have on structural displacement, while also exploring what pressures and duration can be expected during a mine explosion. Additionally, the …