The Experts below are selected from a list of 1965 Experts worldwide ranked by ideXlab platform
V.r. Sastry - One of the best experts on this subject based on the ideXlab platform.
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A numerical modelling approach to assess the behaviour of underground cavern subjected to blast loads
International Journal of Mining Science and Technology, 2018Co-Authors: Saikat Kuili, V.r. SastryAbstract:Abstract The paper gives an insight into the behaviour of large underground caverns which are subjected to blast loads. Caverns are generally constructed in Hard Rock Formation which compels us to use blasting methods for the excavation works. Comparative study was done between models with intact Rock mass and discontinuities to assess the stability of cavern as a result of blast loads. Numerical modelling was performed with 3 dimensional distinct element code (3DEC) to analyse the performance of cavern walls in terms of displacement and to compute peak particle velocities (PPV) both around the cavern periphery and at surface of models. Results showed that the velocity wave with higher frequency exhibited large displacements around the periphery of cavern. Computation of PPV showed that model with horizontal joint sets showed lower PPV in comparison to model with intact Rock mass. PPV values were also analysed on the surface for model consisting vertical joints spaced at 4 m intervals. Comparative study of PPV on surface vertically above the blast location between models with horizontal joints spaced at 4 m and vertical joints at 4 m intervals were conducted. Results depicted higher magnitudes of PPV for model with vertical joints in comparison to model with horizontal joints.
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Rippability assessment of a limestone deposit
2013Co-Authors: V.r. Sastry, K. Ram ChandarAbstract:In the planning stage of a mining project or any excavation project, it is important to select a method of excavation based on the nature of Rock mass. In case of very Hard Rock Formation, drilling and blasting is the only method of extraction but in medium Hard and soft Formations ripping can be adopted, which reduces environmental problems of Rock blasting. For the assessment of rippability of a Rock, various researchers have proposed different Rock mass classifications. In most of the classifications, seismic velocity of the Rock was considered as one of the important parameter. Some others expressed the relation between the seismic velocity of Rock with some physico-mechanical properties of Rock. In this paper an attempt is made to discuss the different Rock mass classifications for rippability assessment and a case study is presented involving assessment of rippability of a limestone deposit.
Jian Tang - One of the best experts on this subject based on the ideXlab platform.
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Matrix material for a new 3D-printed diamond-impregnated bit with grid-shaped matrix
International Journal of Refractory Metals & Hard Materials, 2019Co-Authors: Jingjing Wu, Shaohe Zhang, Feilong Qu, Hou Zhou, Jian TangAbstract:Abstract In order to improve the efficiency of drilling Hard Rock Formation, the matrix structure of diamond-impregnated bit is designed as grid shape, and the basic parameters of this diamond-impregnated bit with grid-shaped matrix is theoretical analyzed. Two kinds of test samples, made by two selected 3D printing materials (Inconel 718 and CoCrMo alloy), are prepared by using powder metallurgy, and the optimum sintering parameter is determined by studying the effect of sintering temperature on three-main mechanical properties, Hardness, abrasive resistance and bending strength. Also the mechanical properties of Inconel 718 and cobalt chromium alloy fetal bodies sintered at the optimum sintering temperature are compared with traditional WC matrix composite. It shows that the Inconel718 and the CoCrMo alloy can possess the optimal mechanical properties when the sintering temperature is 1050 °C. Meanwhile, CoCrMo alloy indicates to be more suitable for the matrix material of DIBGM due to its similar mechanical properties with WC matrix. The 3D printing working layer test and the Rock cutting test confirmed the feasibility of the CoCrMo alloy acting as a matrix material, and the 3D-printed grid pieces that suitable for the Hard Rock with different strength are summarized as well.
Sailesh Samanta - One of the best experts on this subject based on the ideXlab platform.
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GIS, remote sensing and MCE approach for identifying groundwater prospective zones in mountainous region of PNG
Applied Geomatics, 2019Co-Authors: Nebare Poi, Sailesh SamantaAbstract:Water is the most precious resource available for mankind. Due to the rapid increase in population, urbanisation and agricultural expansion place additional demand for water. Groundwater is an alternative source of fresh water available to support a human. However, Papua New Guinea’s (PNG) difficult geography and excessive Hard Rock Formation make it challenging for authorities to carry out groundwater development programs. To combat this complexity, an integrated approach based on remote sensing (RS) and geographic inFormation system (GIS) application through multi-criteria evaluation (MCE) technique was adopted for exploration and delineation of groundwater potential zones. A range of influential factors including geomorphology, lithology, soil, rainfall, drainage, slope, elevation, land use/land cover and inundation were analysed and integrated in ArcGIS10 through weighted overlay index techniques. A detail data evaluation criteria were developed with suitability rankings and weightings applied to each parameter. Weightage were assigned based on probability influence, i.e., geomorphology—16%, soil—16%, lithology—15%, drainage—15%, rainfall—10%, topographic slope—9%, elevation—9%, land use/land cover—5% and inundation—5%. After weighted overlay operations, a groundwater prospective zonal map layer was generated and classified in terms of very poor, poor, moderate, good and very good. The area occupied are poor—2.38%, very poor—11.21%, moderate—60.75%, good—16.47% and very good—9.19% respectively.
Saikat Kuili - One of the best experts on this subject based on the ideXlab platform.
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A numerical modelling approach to assess the behaviour of underground cavern subjected to blast loads
Elsevier, 2018Co-Authors: Saikat Kuili, Vedala Rama SastryAbstract:The paper gives an insight into the behaviour of large underground caverns which are subjected to blast loads. Caverns are generally constructed in Hard Rock Formation which compels us to use blasting methods for the excavation works. Comparative study was done between models with intact Rock mass and discontinuities to assess the stability of cavern as a result of blast loads. Numerical modelling was performed with 3 dimensional distinct element code (3DEC) to analyse the performance of cavern walls in terms of displacement and to compute peak particle velocities (PPV) both around the cavern periphery and at surface of models. Results showed that the velocity wave with higher frequency exhibited large displacements around the periphery of cavern. Computation of PPV showed that model with horizontal joint sets showed lower PPV in comparison to model with intact Rock mass. PPV values were also analysed on the surface for model consisting vertical joints spaced at 4 m intervals. Comparative study of PPV on surface vertically above the blast location between models with horizontal joints spaced at 4 m and vertical joints at 4 m intervals were conducted. Results depicted higher magnitudes of PPV for model with vertical joints in comparison to model with horizontal joints. Keywords: Large underground caverns, Hard Rock Formation, Numerical modelling, 3 dimenssional distinct element code, Peak particle velocitie
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A numerical modelling approach to assess the behaviour of underground cavern subjected to blast loads
International Journal of Mining Science and Technology, 2018Co-Authors: Saikat Kuili, V.r. SastryAbstract:Abstract The paper gives an insight into the behaviour of large underground caverns which are subjected to blast loads. Caverns are generally constructed in Hard Rock Formation which compels us to use blasting methods for the excavation works. Comparative study was done between models with intact Rock mass and discontinuities to assess the stability of cavern as a result of blast loads. Numerical modelling was performed with 3 dimensional distinct element code (3DEC) to analyse the performance of cavern walls in terms of displacement and to compute peak particle velocities (PPV) both around the cavern periphery and at surface of models. Results showed that the velocity wave with higher frequency exhibited large displacements around the periphery of cavern. Computation of PPV showed that model with horizontal joint sets showed lower PPV in comparison to model with intact Rock mass. PPV values were also analysed on the surface for model consisting vertical joints spaced at 4 m intervals. Comparative study of PPV on surface vertically above the blast location between models with horizontal joints spaced at 4 m and vertical joints at 4 m intervals were conducted. Results depicted higher magnitudes of PPV for model with vertical joints in comparison to model with horizontal joints.
Jingjing Wu - One of the best experts on this subject based on the ideXlab platform.
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Matrix material for a new 3D-printed diamond-impregnated bit with grid-shaped matrix
International Journal of Refractory Metals & Hard Materials, 2019Co-Authors: Jingjing Wu, Shaohe Zhang, Feilong Qu, Hou Zhou, Jian TangAbstract:Abstract In order to improve the efficiency of drilling Hard Rock Formation, the matrix structure of diamond-impregnated bit is designed as grid shape, and the basic parameters of this diamond-impregnated bit with grid-shaped matrix is theoretical analyzed. Two kinds of test samples, made by two selected 3D printing materials (Inconel 718 and CoCrMo alloy), are prepared by using powder metallurgy, and the optimum sintering parameter is determined by studying the effect of sintering temperature on three-main mechanical properties, Hardness, abrasive resistance and bending strength. Also the mechanical properties of Inconel 718 and cobalt chromium alloy fetal bodies sintered at the optimum sintering temperature are compared with traditional WC matrix composite. It shows that the Inconel718 and the CoCrMo alloy can possess the optimal mechanical properties when the sintering temperature is 1050 °C. Meanwhile, CoCrMo alloy indicates to be more suitable for the matrix material of DIBGM due to its similar mechanical properties with WC matrix. The 3D printing working layer test and the Rock cutting test confirmed the feasibility of the CoCrMo alloy acting as a matrix material, and the 3D-printed grid pieces that suitable for the Hard Rock with different strength are summarized as well.
