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Kinematic Assessment of Rock Slope Stability at Obajana and Ewekoro Quarries
Saliu Muyideen Alade,
Shehu Shaib Abdulazeez
Issue:
Volume 3, Issue 2, April 2014
Pages:
34-41
Received:
18 February 2014
Accepted:
8 April 2014
Published:
10 April 2014
Abstract: The research work assessed the stability of rock slopes for optimum exploitation of limestone deposits at Obajana in Kogi State and Ewekoro in Ogun state. Geological mapping was carried out to measure the orientations of discontinuities. The orientation data obtained were plotted on stereonets to determine pole concentration and major joint sets using Dips 5.0 software from Rocscience. Two joint sets were identified in Obajana with orientations of 720/0890 and 880/2210 while three joint sets with orientations of 610/0480, 160/2800 and 900/1400 were identified in Ewekoro quarry face. The Dips software was further used to perform kinematic analyses for toppling, planar and wedge failures for each of the faces investigated. The friction angles for the kinematic analyses were obtained using Roclab 1.0 software (Rocscience, 2002). The results of the analyses show that toppling failure cannot occur in Obajana while planar and wedge failures may occur. The three failure modes (toppling, planar and wedge) were identified in Ewekoro.
Abstract: The research work assessed the stability of rock slopes for optimum exploitation of limestone deposits at Obajana in Kogi State and Ewekoro in Ogun state. Geological mapping was carried out to measure the orientations of discontinuities. The orientation data obtained were plotted on stereonets to determine pole concentration and major joint sets us...
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Assessment of Excavation Method of Obajana and Ewekoro Limestone Deposits
SALIU Muyideen Alade,
SHEHU Shaib Abdulazeez
Issue:
Volume 3, Issue 2, April 2014
Pages:
42-49
Received:
19 February 2014
Accepted:
8 April 2014
Published:
10 April 2014
Abstract: The research work assessed the optimum excavation method of limestone deposits at Obajana in Kogi State and Ewekoro in Ogun state. Geological mapping was carried out to measure the orientations of discontinuities. The orientation data obtained were plotted on stereonets to determine pole concentration and major joint sets using Dips 5.0 software from Rocscience. Two joint sets were identified in Obajana with orientations of 720/0890 and 880/2210 while three joint sets with orientations of 610/0480, 160/2800 and 900/1400 were identified in Ewekoro quarry face. Schmidt hammer hardness and Unit weight tests were performed. The results obtained were used to evaluate the Uniaxial Compressive Strength (UCS) and consequently, the Point load index (Is) of the rock studied. The excavation method was assessed using Discontinuity Spacing Index (If), the Point load index (Is) and the Geological Strength Index (GSI). The discontinuity spacing index was evaluated from the major joint sets identified and the determination of the volumetric joint count (Jv).The geological strength index was estimated using an inbuilt chart of RocLab 1.0 from Rocscience. Excavation assessments revealed that “Very Hard Ripping” is a possible method of excavating Obajana and Ewekoro Type III deposits while the less dense Type I deposit of Ewekoro can be “Ripped”. The only feasible excavation method for Ewekoro type II deposit is “Blasting”.
Abstract: The research work assessed the optimum excavation method of limestone deposits at Obajana in Kogi State and Ewekoro in Ogun state. Geological mapping was carried out to measure the orientations of discontinuities. The orientation data obtained were plotted on stereonets to determine pole concentration and major joint sets using Dips 5.0 software fr...
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Surface and Subsurface Temperature Variations during 2009 El Niño Manifestation over Central and Tropical Pacific Ocean
Issue:
Volume 3, Issue 2, April 2014
Pages:
50-57
Received:
28 February 2014
Accepted:
10 April 2014
Published:
20 April 2014
Abstract: Tropical Pacific Ocean is an important to study for identifying the influence on Global circulation. El Niño /La Nina even occurs over the tropical Pacific Ocean, with temperatures oscillations. With respect to increase in temperatures, the intensity of El Niño can be divided into strong, moderate and weak. As per the intensity, the year 2009 is a moderate El Niño, but is peculiar due to delay in formation. In this article, TAO/TRITON data is used for analysis between November 2008 and December 2009 to check the variations in the surface and sub-surface temperatures during the manifestation of El Niño. Actually El Niño manifest during December, but during 2009 El Niño it manifested in January. There is a clear evidence in surface and sub-surface temperatures as they are increasing from January 2009, which can explains the manifestation of El Niño
Abstract: Tropical Pacific Ocean is an important to study for identifying the influence on Global circulation. El Niño /La Nina even occurs over the tropical Pacific Ocean, with temperatures oscillations. With respect to increase in temperatures, the intensity of El Niño can be divided into strong, moderate and weak. As per the intensity, the year 2009 is a ...
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Future Trend of Mineral Industries Development in Indonesia
Ukar Wijaya Soelistijo,
La Ode Aswandi
Issue:
Volume 3, Issue 2, April 2014
Pages:
58-67
Received:
15 April 2014
Accepted:
26 April 2014
Published:
10 May 2014
Abstract: The aim of this study is to figure out the vision of effort of utilizing the remainder of the available mineral asset in the country, where Indonesia is necessarily seeking new opportunity toward developing mineral industry (hydro-carbon, metal, and non-metal) such as fine chemical industry, alloy (stainless/tool steel), fibre, ceramic block, super/semiconductor in the purpose of supporting super downstream industry that could produce massive mineral products containing high added value. Moreover, those downstream industries require high quantity and quality of minerals as raw material. The methodology applied in this study is based on a descriptive analytical method combined with dynamic commodity models to find the problems encountered in the effort to gain highest added value in mineral utilization.
Abstract: The aim of this study is to figure out the vision of effort of utilizing the remainder of the available mineral asset in the country, where Indonesia is necessarily seeking new opportunity toward developing mineral industry (hydro-carbon, metal, and non-metal) such as fine chemical industry, alloy (stainless/tool steel), fibre, ceramic block, super...
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