Ground vibrations from blasting are acoustic waves that propagate through the earth. They are also termed seismic waves because their propagation characteristics are similar to the ground motions produced by earthquakes. Amplitude of ground vibration induced by blasting may vary significantly at or around an open pit mine depending on parameters such as the maximum amount of explosive detonating at a time interval and the physical distance between the shot and the location of concern, whereas the frequency of vibration mainly vary depending on the geology and blast delay intervals. Therefore evaluation and assessment of ground vibration condition at or around an open pit mine is necessary. The objective of the proposed research study is to monitor and record the ground vibration and to investigate and assess the vibration conditions at neighbouring districts that are induced by production blasting operations at Usak KiSladag Gold Mine. In this research study, several parameters such as the ground vibration velocity, the amount of charge per delay, the physical distance to the location of monitoring device or residential structures are recorded, analyzed and evaluated together with the frequencies of the seismic waves. The determined ground vibration velocities are compared with the allowable limits given in Turkish Regulation and US Federal Regulation. Thus, the compliance of the ground vibrations with the above mentioned regulations are discussed and assessed. Furthermore, the parameters which affect the ground vibration are discussed and determined. In this study, the monitored and the recorded ground vibrations are evaluated from structural damage potential and human disturbance points of views. It is determined that the ground vibration levels recorded during this study and analyzed from the past records comply with Turkish and US Federal regulations. It is concluded that no damage has been occurred in structures at surrounding settlements and the occupants were not disturbed by the direct effect of vibrations in the past and at present. The analysis proved that the blasting operations to be conducted in the future will not create any damage and disturbance provided that the charge detonated per delay is kept less than 155 kg&amp / #8217 / s.

The aim of the study was to investigate the crystallization kinetics and solidification behaviour of Fe60Co8Mo5Zr10W2B15 bulk glass forming alloy. The solidification behaviour in near-equilibrium and non-equilibrium cooling conditions was studied. The eutectic and peritectic reactions were found to exist in the solidification sequence of the alloy. The bulk metallic glass formation was achieved by using two methods: quenching from the liquid state and quenching from the semi-state. Scanning electron microscopy, x-ray diffraction and thermal analysis techniques were utilized in the characterization of the samples produced throughout the study. The choice of the starting material and the alloy preparation method was found to be effective in the amorphous phase formation. The critical cooling rate was calculated as 5.35 K/s by using the so-called Barandiaran and Colmenero method which was found to be comparable to the best glass former known to date. The isothermal crystallization kinetics of the alloy was studied at temperatures chosen in the supercooled liquid region and above the first crystallization temperature. The activation energies for glass transition and crystallization events were determined by using different analytical methods such as Kissinger and Ozawa methods. The magnetic properties of the alloy in the annealed, amorphous and as-cast states were characterized by using a vibrating sample magnetometer. The alloy was found to have soft magnetic properties in all states, however the annealed specimen was found to have less magnetic energy loss as compared to the others.

The aim of this study was to produce zirconium diboride (ZrB2) and other metal borides such as lanthanum hexaboride (LaB6) and cerium hexaboride (CeB6) by magnesiothermic reduction (reaction of metal oxide, boron oxide and magnesium) using volume combustion synthesis (VCS) and mechanochemical process (MCP). Production of ZrB2 by VCS in air occurred with the formation of side products, Zr2ON2 and Mg3B2O6 in addition to MgO. Formation of Zr2ON2 was prevented by conducting VCS experiments under argon atmosphere. Wet ball milling was applied before leaching for easier removal of Mg3B2O6. Leaching in 5 M HCl for 2.5 hours was found to be sufficient for removal of MgO and Mg3B2O6. By MCP, 30 hours of ball milling was enough to produce ZrB2 where 10% of excess Mg and B2O3 were used. MgO was easily removed when MCP products were leached in 1 M HCl for 30 minutes. Complete reduction of ZrO2 could not be achieved in either production method because of the stability of ZrO2. Hence, after leaching VCS or MCP products, final product was composed of ZrB2 and ZrO2. Formation of LaB6 and CeB6 were very similar to each other via both methods. Mg3B2O6 appeared as a side product in the formation of both borides by VCS. After wet ball milling, products were leached in 1 M HCl for 15 hours and pure LaB6 or CeB6 was obtained. As in ZrB2 production, 30 hours of ball milling was sufficient to form these hexaborides by MCP. MgO was removed after leaching in 1 M HCl for 30 minutes and the desired hexaboride was obtained in pure form.

Semi-circular specimens (SCB) under three point-bending which are commonly used for fracture testing of rocks were used here for fracture mechanics tests. A total of 65 specimens were tested by using Ankara andesite rock. Investigations including the effects of initial notch thickness, different loading span ratios (S/R), flattened loading end, and little dimensional variations when preparing the specimens were carried out. Stress intensity factors for specimens with different geometries were computed individually by using a 3D finite element program ABAQUS. Specimens with a preliminary notch thickness varying from 0.84 to 3.66 mm were tested under three point bending. For a second group of specimens loading span was changed and fracture toughness variation was studied. Another change in the specimen geometry was made by machining a flat loading end at the upper load application point. Fracture toughness values were computed using the stress intensity values computed from numerical modeling and failure loads from the experiments. It was found that up to 2 mm fracture toughness was not affected by variations in the thickness of preliminary notches. Fracture toughness was not affected by changing the loading span. For specimens with flat loading ends, fracture toughness was about 16% lower than the value found from regular SCB type specimens loaded at a point at the top by a steel roller. As a result of about 46 experiments average fracture toughness of Ankara G&ouml / lbasi andesite was found as 1.36 MPa .

Most of the coal properties depend on carbon content and vitrinite reflectance, which are rank dependent parameters. In this study, a new approach was followed by constructing a simulation input database with rank-dependent coal properties published in the literature which are namely cleat spacing, coal porosity, density, and parameters related to strength of coal, shrinkage, swelling, and sorption. Simulations related to enhanced coalbed methane (ECBM) recovery, which is the displacement of adsorbed CH4 in coal matrix with CO2 or CO2/N2 gas injection, were run with respect to different coal properties, operational parameters, shrinkage and swelling effects by using a compositional reservoir simulator of CMG (Computer Modeling Group) /GEM module. Sorption-controlled behavior of coalbeds and interaction of coal media with injected gas mixture, which is called shrinkage and swelling, alter the coal properties controlling gas flow with respect to injection time. Multicomponent shrinkage and swelling effects were modeled with extended Palmer and Mansoori equation. In conclusion, medium-volatile bituminous coal rank, dry coal reservoir type, inverted 5-spot pattern, 100 acre drainage area, cleat permeability from 10 to 25 md, CO2/N2 molar composition between 50/50 % and 75/25 %, and drilling horizontal wells rather than vertical ones are better selections for ECBM recovery. In addition, low-rank coals and dry coal reservoirs are affected more negatively by shrinkage and swelling. Mixing CO2 with N2 prior to its injection leads to a reduction in swelling effect. It has been understood that elastic modulus is the most important parameter controlling shrinkage and swelling with a sensitivity analysis.

Shear strength characterization of discontinuities is an important concept for slope design in discontinuous rocks. This study presents the development of a methodology for implementing Barton-Bandis empirical shear strength failure criterion in three dimensional distinct element code, 3DEC, and verification of this methodology. Normal and shear deformation characteristics of discontinuities and their relations to the discontinuity surface characteristics have been reviewed in detail. First, a C++ dynamic link library (DLL) file was coded and embedded into 3DEC for modelling the Barton-Bandis shear strength criterion. Then, a numerically developed direct shear test model was used to verify the normal and shear deformation behaviour with respect to empirical results of the Barton-Bandis shear strength criterion. A three dimensional simple discontinuous rock slope was modelled in 3DEC based on Barton-Bandis shear strength criterion. The slope model was first utilized by Mohr-Coulomb failure criterion. Then, with the use of the new model developed here, the effects of the discontinuity surface properties on shear strength were introduced to the slope problem. Applicability of the developed model was verified by three large scale real case studies from different open pit lignite mines of Turkish Coal Enterprises (TKi), namely Bursa Lignites Establishment (BLi) &ndash / 2 cases and &Ccedil / an Lignite Establishment (&Ccedil / Li). The results with the new model option, which allows users to use important discontinuity surface properties like joint roughness coefficient and joint wall compressive strength, compared well with results of previous studies using Mohr-Coulomb failure criterion.

The profitability of a mineral deposit can be concluded by the comparison of net present values (NPV) of all revenues and expenditures. In the estimation of NPV of a mineral deposit, many parameters are used. The parameters are uncertain. More accurate and reliable NPV estimation can be done with considering the related uncertainties. This study investigates the probability distributions of uncertain variables in estimation of NPV and evaluation of NPV using Monte Carlo simulation. @Risk 4.5.7 software package is used to apply Monte Carlo simulation method. At the end of the study, all possible net present values and their probabilities are given as a probability distribution. Derek&ouml / y copper ore reserve is selected to apply uncertainty assessment in NPV of ore reserves. The reserve is evaluated using both conventional polygonal method and a mining software which is Micromine. The southeastern part of the reserve was selected as a study area because average grade of the reserve is relatively low and the reserve extends to a larger area. At the end of the assessment, NPV of the southeastern part of Derek&ouml / y ore reserve was found to be between $77.97&times / 106 and $318.78&times / 106 with 68.27% (x&plusmn / &amp / #963 / ) probability and between &ndash / $45.37&times / 106 and $443.54&times / 106 with 95.45% probability (x&plusmn / 2&amp / #963 / ).

In the recent years, ongoing debates in the mineral sector has shown that efficient use of natural resources is of vital importance as the use of minerals is essential for modern living. Especially, in the context of sustainable development, it is required that mineral resources should be exploited to maximize the contribution to the well being of current generation without depriving the potential for future generations to meet their own needs. The aim of this thesis is to develop a decision support system using system dynamics methodology where

Groundwater can be a critical issue to be considered in civil engineering, mining engineering and interdisciplinary fields. Karstic structures and aquifers enclosing groundwater are potential risks in case they are not studied in detail. Enclosed groundwater can result in floods at pit bottom or can cause instabilities of permanent pit slopes. This study is about analyses of flooding possibility at the pit bottom and possible instabilities of pit slopes in the Elbistan-&Ccedil / &ouml / llolar open cast coal mine due to the presence of a karstic aquifer under the lignite formation. Thickness and permeability of the bottom clay formation under the lignite bed are necessary critical parameters for investigating a possible water rush from a confined aquifer in limestone formation underneath the bottom clay. These parameters were changed, and water flow quantities towards the pit bottom were determined by finite element models. Critical values of these parameters were investigated considering the lack of accurate site investigation information regarding the thickness and permeability of bottom clay. Possible strength loss, fracturing, and thus permeability increase in bottom clay due to a confined aquifer were studied. In flooding and slope stability analyses Phase2 software based on finite element method is used. Results of analyses showed that as reported thickness of bottom clay is around 120 m at the pit bottom and permeability values are in orders of magnitudes of 10-8 m/s, no serious flooding problems are expected to occur unless the thickness of bottom clay layer drops down to around 20 m, and the permeability of this layer reaches an order of magnitude of 10-5 m/s. Mechanical effects of confined aquifer on slopes and bottom clay displacements were investigated, and thus fracturing and failure possibilities of bottom clay and permanent slope were assessed. Slope and pit bottom displacements increased to meter levels for less than 60 m bottom clay thicknesses. Whereas 50-60 m bottom clay thickness can be critical for cracking, 20 m bottom clay thickness was found to be critical for water rush to the pit bottom. With reported bottom clay thickness of 120 m and with 25o slope angle permanent slope factor of safety was found to be 1.2, and this value was not effected unless clay layer thickness drops below 70 m levels. Higher than 32o overall slope angle there will be a risk of slope failure for permanent and production slopes, reflected by safety factors less than one, in the stability analyses.

Real-time optimization of drilling parameters during drilling operations aims to optimize weight on bit, bit rotation speed for obtaining maximum drilling rate as well as minimizing the drilling cost. The process is considered to be formation specific. A statistical method such as multiple linear regression technique has been used for the drilling optimization. An extensive literature survey on drilling optimization was conducted for this research study. A model is developed for this purpose using actual field data collected through modern well monitoring and data recording systems, which predicts the rate of drilling penetration as a function of available parameters. The rate of penetration general equation is optimized for effective functions at each data point. In order to optimize the parameters in the field, a computer network is required to be developed. The computer network will keep the piped data directly from the data source, and continuously be collecting the new data to be fed. A database present at the central computer will be continuously calculating the developed model parameters by means of multiple regression technique and inform the team at the field. The field engineer will transmit the current drilling parameters back to the central computer, and the headquarters will determine the new model parameters and optimum drilling parameters by including the recently received information. Therefore, there will be a real-time-optimization process. It is considered that this technique is going to be widely used in future drilling activities since it could reduce drilling costs and minimize probability of encountering problems due to working with optimized parameters. It has been found that drilling rate of penetration could be modelled in real-time environment as a function of independent drilling variables such as weight on bit, rotation speed of the string, drilling fluid weight, and formation characteristics. The ability to have the drilling rate of penetration with respect to depth characteristically with certain parameters for specific formations on real-time basis could bring new insights to the nature of drilling optimization studies. Any significant departure of the actual rate of penetration from the predicted rate of penetration trend could have important indications which could be detected beforehand in real-time. The study has also achieved one of its objectives, giving the optimized independent drilling parameters found following statistical synthesis.