The Experts below are selected from a list of 12 Experts worldwide ranked by ideXlab platform
Radford B. Langston - One of the best experts on this subject based on the ideXlab platform.
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Modeling of Geotechnical Parameters for Mine Planning Purposes at the Stillwater Pt - Pd Mine, Nye, Montana.
1998Co-Authors: Radford B. LangstonAbstract:At the Stillwater Mine, geotechnical parameters determining rockmass quality are estimated using inverse distance modeling. Plots produced for mine-planning purposes are constructed in both block and contour format. Unconfined compressive strength, block size, friction angle, stress reduction factor and rockmass quality are displayed in this manner. Production and exploration core drilling is logged for RQD, Joint set Number (Jn), Joint Roughness Number (Jr), Joint alteration Number (Ja), and point load index. The point load index is converted to a UCS value by the use of a correlation curve. Drill runs are flagged in relative stratigraphic assemblages as footwall below the zone of interest, zone of interest and hanging wall above the zone of interest. These flagged zones are then length weight composited. Subsequent modeling of the composite intervals using an inverse distance algorithm with a weighting exponent of one produces output displayed as posted cell values and contour plots in longitudinal section on the plane of the ore zone. Use of this data allows more optimal planning of mining methods, planning of ancillary excavations and prediction of potential ground conditions within a given stoping block. Optimization of the estimation technique and validation of results are currently ongoing.
R. Bhasin - One of the best experts on this subject based on the ideXlab platform.
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Rock mass characterization for large caverns in India and Norway using a new method of recording and presenting engineering geological data
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1994Co-Authors: R. BhasinAbstract:This paper presents some applications of a new method of recording and presenting key geotechnical parameters, including the data required for rock mass classification using the Q-system. It describes geotechnical logging work, performed during the benching operations at two sites. The first site is the 200m long, 23m wide, 56m high underground powerhouse of the Sarsar Sarovar hydroelectric project in Gujarat, India. The second site is the 91m long, 61m wide, 24m high underground Winter Olympics stadium at Lillehammer, Norway. The geotechnical data at both sites were recorded on logging charts displaying histograms, and then punched into a personal computer running a spreadsheet, allowing the data to be combined and manipulated according to users' wishes. The six Q-method parameters, estimated from these data, were: (1) rock quality designation; (2) Joint set Number; (3) Joint Roughness Number; (4) Joint alteration Number; (5) Joint water reduction factor; and (6) stress reduction factor. They are essential to the process of predicting rock mass behaviour. All parameters, considered important when performing field mapping and core drilling, are described briefly. Some examples of the graphical logging results for both sites are displayed.
Ruwan Rajapakse - One of the best experts on this subject based on the ideXlab platform.
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Rock Mechanics and Foundation Design in Rock
Geotechnical Engineering Calculations and Rules of Thumb, 2020Co-Authors: Ruwan RajapakseAbstract:Very high load foundations, caissons, and piles are carried down to the rock layer to increase the bearing capacity. Rock can provide a much higher bearing capacity than soil. Unweathered rock can have a bearing capacity in excess of 60 tsf. On the other hand, weathered rock or rocks subjected to chemical attack could be unsuitable for foundation use. This chapter provides a brief overview of rocks and types with a focus on volcanic eruption and lava flow. The identification of rock type is important to the foundation or tunneling engineer. The suitability of a rock for foundation use is dependent upon rock Joints. A rock Joint is basically a fracture in the rock mass. Most rocks consist of Joints. Joints could occur in the rock mass due to many reasons. Information regarding rock formations is obtained through rock coring—a process whereby a rotating diamond cutter is pressed to the bedrock. Core loss information is more important than rock core information. The coring rate, the color of the return water, and the arrangement of the core in the box can be used to identify the location of core loss. Finally, this chapter explains the procedure to obtain the Joint Roughness Number.
K. S. Krishna Murthy - One of the best experts on this subject based on the ideXlab platform.
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Geological and geotechnical investigations of Loharinag-Pala Hydroelectric Project, Garhwal Himalaya, Uttarakhand
Journal of the Geological Society of India, 2009Co-Authors: Ajay K. Naithani, A. K. Bhatt, K. S. Krishna MurthyAbstract:The project area, forming a part of Bhagirathi valley, exposed rocks classed as central Himalayan crystallines and are medium to high grade metamorphics. The rock types exposed are feldspathic gneisses, quartz-biotite schists, garnet-biotite schist, biotite gneisses, migmatites and amphibolites. To design the rock support for the underground structures of desilting chambers, HRT, surge shaft, pressure shafts, power house, TRT and for the foundations of barrage and intake of desilting chambers, rock mass classifications was attempted following the methods of Bieniawski Rock Mass Rating (RMR) Classification and Tunnelling Quality Index (Q) of Barton et al. RMR technique involves collection of data on rock strength, RQD (%), spacing of discontinuities, condition of discontinuities and groundwater condition, while the ‘Q’ involves collection of data on RQD (%), Joint set Numbers (Jn), Joint Roughness Number (Jr), Joint alternation Number (Ja), Joint water reduction factor (Jw) and stress reduction factors (SRF). The permeability test in the overburden was done by the constant head method, while in the bed rock portion conducted by packer test. The result indicates that the rock masses of the area fall under the good, fair and poor rock quality. Augen gneiss of power house area is coming under the category of moderately strong rock as proved by deformability characteristics and strength parameter. On the basis of above study recommendations have been made for the proper and safe construction of the project components.
Ajay K. Naithani - One of the best experts on this subject based on the ideXlab platform.
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Geological and geotechnical investigations of Loharinag-Pala Hydroelectric Project, Garhwal Himalaya, Uttarakhand
Journal of the Geological Society of India, 2009Co-Authors: Ajay K. Naithani, A. K. Bhatt, K. S. Krishna MurthyAbstract:The project area, forming a part of Bhagirathi valley, exposed rocks classed as central Himalayan crystallines and are medium to high grade metamorphics. The rock types exposed are feldspathic gneisses, quartz-biotite schists, garnet-biotite schist, biotite gneisses, migmatites and amphibolites. To design the rock support for the underground structures of desilting chambers, HRT, surge shaft, pressure shafts, power house, TRT and for the foundations of barrage and intake of desilting chambers, rock mass classifications was attempted following the methods of Bieniawski Rock Mass Rating (RMR) Classification and Tunnelling Quality Index (Q) of Barton et al. RMR technique involves collection of data on rock strength, RQD (%), spacing of discontinuities, condition of discontinuities and groundwater condition, while the ‘Q’ involves collection of data on RQD (%), Joint set Numbers (Jn), Joint Roughness Number (Jr), Joint alternation Number (Ja), Joint water reduction factor (Jw) and stress reduction factors (SRF). The permeability test in the overburden was done by the constant head method, while in the bed rock portion conducted by packer test. The result indicates that the rock masses of the area fall under the good, fair and poor rock quality. Augen gneiss of power house area is coming under the category of moderately strong rock as proved by deformability characteristics and strength parameter. On the basis of above study recommendations have been made for the proper and safe construction of the project components.
