C. Fairhurst - Academia.edu (original) (raw)
Papers by C. Fairhurst
International Journal of Rock Mechanics and Mining Sciences, 1997
The stability of a circular tunnel in an elasto-plastic (brittle) material subjected to gravitati... more The stability of a circular tunnel in an elasto-plastic (brittle) material subjected to gravitational loading is studied by considering the occurrence of a minimum in the ground reaction curve (i.e. the characteristic load-deformation curve for the opening). The relations between the gravitational load and the post-peak load strength of the material are expressed in the form of limit-depth charts, i.e. dimensionless graphical representations that allow a direct assessment of the stability conditions. The analysis is extended to the face of the tunnel where the 3-D problem is treated analytically under certain restrictive assumptions. Practical examples illustrating the use of the charts for shallow tunnels in weak material and for deep tunnels in hard rock are presented.
Geo-Science and Geo-Engineering Research at DUSEL ii Illustration of Possible Experiments in DUSE... more Geo-Science and Geo-Engineering Research at DUSEL ii Illustration of Possible Experiments in DUSEL. Most of the caverns excavated in DUSEL, both at intermediate and deep levels, will be designed to accommodate physics experiments. Excavation of these caverns provides excellent research opportunities for geoscience and geoengineering and geomicrobiology. Development of roadways to the underground facilities provides access to large volumes of rock and further opportunities for research e.g. in ‘niches ’ excavated from the main access drifts This diagram, which is illustrative only, shows examples of the types of geo-experiments that are possible in DUSEL. These are discussed in detail in this report. Actual layout of the underground and design of the experiments will depend on the geology of the site selected for DUSEL. Note: Although a specific location is indicated for experiments on ‘Transparent Earth’, most of the experiments also will involve measurement and observation techniqu...
Proceedings of Conference on Drilling and Rock Mechanics, 1965
Engineering Geology, 1972
Testing machines have become increasingly sophisticated and versatile since they were first intro... more Testing machines have become increasingly sophisticated and versatile since they were first introduced in the early eighteenth century. Two recent advances in testing machine technology are of particular importance for laboratory studies of rock failure: the development of machines with stiff frames and the use of feedback control systems. Force has been traditionally regarded as the independent variable in materials testing but the inevitable outcome of a rock mechanics test with a constant loading rate is violent uncontrolled failure at the peak of the force-displacement curve. Rock failure can be controlled if displacement is regarded as the independent variable and a constant displacement rate can be achieved in a testing machine with a stiff frame or a feedback control system. This review contains a brief history of testing machines and a detailed discussion of the principles involved in controlling rock failure with stiff and servtycontrolled testing machines. The development of stiff testing machines is followed from 1935 to the present day and the rock specimen stiffness and testing machine stiffness (factors that are neither fixed nor independent) are discussed in detail. In a closed-loop servo-controlled testing machine, the ability to control rock failure is governed by the fast response time and correct choice of feedback signal. These factors are explained and examples are given of the precise control that can now be achieved in experimental studies of rock failure that were impractical or impossible several years ago.
Rock Mechanics Felsmechanik Mecanique des Roches, 1972
Controlled Failure of Hollow Rock Cylinders in Uniaxial Compression. Detailed consideration is gi... more Controlled Failure of Hollow Rock Cylinders in Uniaxial Compression. Detailed consideration is given to the behavior of hollow rock cylinders loaded in uniaxial compression. Elastic stress distributions calculated by the finite element method show that radial stresses are considerably lower in hollow than in solid cylinders, and that the uniformity of the stresses can be improved considerably by using loading platens having the same cross-section as the specimen. Servo-controlled uniaxial compression tests carried out on solid and thick-walled cylinders of white Tennessee marble show no essential differences in the behavior of the two specimen types with similar strengths and fracture phenomena being observed. In tests carried out in servo-controlled, stiff, and conventional machines, the progressive formation of large numbers of short subaxial cracks is followed by the development of macrofractures such as slabbing and shearing well past the peak of the stress-strain curve. Der gesteuerte Bruch hohler Gesteinszylinder unter einachsigem Druck. Das Verhalten hohler Gesteinszylinder unter einachsigem Druck ist eingehend beschrieben. Die Methode der endlichen Elemente erm6glicht die Berechnung der elastischen Spannungsverteilung und zeigt, dat~ die radialen Spannungen im Hohlzylinder bedeutend geringer sind als im massiven. Der Gebrauch von Druckplatten yore gleichen Querschnitt wie dem der Probe verbessert die Gleichf6rmigkeit der Spsnnungen wesentlich. Servo-gesteuerte einachsige Druckversuche an dichtwandigen hohlen und an massiven Proben yon weif~em Tennessee-Marmot lassen keine wesentlichen Unterschiede zwischen dem Verhalten der beiden Probenarten erkennen. Abnliche Festigkeiten und Brucherscheinungen sind im hohlen und massiven Zylinder beobachtet worden. In Versuchen mit servo-gesteuerten starren und in konventionellen
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1984
The theoretical background of the method is outlined for both the porous-permeable and nonporous ... more The theoretical background of the method is outlined for both the porous-permeable and nonporous cases in isotropic rocks. It is found that, whereas no parameters of the rocks are required for the nonporous case, 3 poro-elastic constants must be known in dealing with porous formations. Laboratory tests on isotropic materials show that the method is reliable for determining both the exact orientation of the principal stresses and their magnitude. Whereas the method may be used successfully in elastic isotropic rock where the largest principal compressive stress is parallel to the axis of the borehole, it may prove less informative when this is not the case. If the method is employed in a mine tunnel, the necessary boreholes could be drilled in both horizontal and vertical directions and the principal stresses determined in all cases.
Journal of the Japanese Association for Petroleum Technology
Tunnelling and Underground Space Technology
Fall Meeting of the Society of Petroleum Engineers of AIME, 1970
Journal of Petroleum Technology, 1969
... The platen also served as a chan-nel for the pressurizing fluid flowingtoward the verti-cal c... more ... The platen also served as a chan-nel for the pressurizing fluid flowingtoward the verti-cal central hole. The loading system for the cylindrical samples was a pressure jacket shnilar to that described by Obert.'z The specimen (5.0 in. in diameter, 6.0 in. ...
A summary of the Earth Science Workshop, Lead, South Dakota, October 4-7 2001, on the planned dev... more A summary of the Earth Science Workshop, Lead, South Dakota, October 4-7 2001, on the planned development of earth science research at the proposed National Underground Science Laboratory (NUSL) will be presented. The Homestake Mine in South Dakota will cease gold production in 2002. The Mine has been recommended for conversion into a NUSL by a national underground science committee and is the focus of a major (physics) proposal to the National Science Foundation. The Earth Science Workshop, associated with the Conference on Underground Science, was held to discuss the type of studies that could be conducted in the Mine and associated practical aspects such as space and time requirements. Construction of the NUSL (estimated to take approximately five years) will involve a variety of rock mechanics and geotechnical studies necessary for the design and excavation of large test chambers at depth for physics experiments, extension of access drifts, and enlargement and deepening of the Y...
One of the main functions of rock mechanics research has been to find ways of determining in situ... more One of the main functions of rock mechanics research has been to find ways of determining in situ stresses. Most methods usually employ some instrumentation for the purpose of measuring hole deformation. The method of hydraulic fracturing has been suggested, because it has been shown that the recorded pressures can be theoretically related to magnitudes of the principal in situ stresses; the orientation of the fracture can often be used to determine the direction of the principal stresses. The advantage of hydraulic fracturing over the present in situ stress determination methods is simplicity: no sophisticated instrumentation is required inside the borehole; hence, the stresses can be measured at any depth. If the formation is impermeable to the fracturing fluid, no elastic constants of the rock are required in calculating the stresses, a factor that not only simplifies the problem, but renders the results more reliable. The theoretical considerations are discussed. A laboratory ex...
Trends in Rock Mechanics, 2000
SPE Drilling and Rock Mechanics Conference, 1973
International Journal of Rock Mechanics and Mining Sciences, 1997
The stability of a circular tunnel in an elasto-plastic (brittle) material subjected to gravitati... more The stability of a circular tunnel in an elasto-plastic (brittle) material subjected to gravitational loading is studied by considering the occurrence of a minimum in the ground reaction curve (i.e. the characteristic load-deformation curve for the opening). The relations between the gravitational load and the post-peak load strength of the material are expressed in the form of limit-depth charts, i.e. dimensionless graphical representations that allow a direct assessment of the stability conditions. The analysis is extended to the face of the tunnel where the 3-D problem is treated analytically under certain restrictive assumptions. Practical examples illustrating the use of the charts for shallow tunnels in weak material and for deep tunnels in hard rock are presented.
Geo-Science and Geo-Engineering Research at DUSEL ii Illustration of Possible Experiments in DUSE... more Geo-Science and Geo-Engineering Research at DUSEL ii Illustration of Possible Experiments in DUSEL. Most of the caverns excavated in DUSEL, both at intermediate and deep levels, will be designed to accommodate physics experiments. Excavation of these caverns provides excellent research opportunities for geoscience and geoengineering and geomicrobiology. Development of roadways to the underground facilities provides access to large volumes of rock and further opportunities for research e.g. in ‘niches ’ excavated from the main access drifts This diagram, which is illustrative only, shows examples of the types of geo-experiments that are possible in DUSEL. These are discussed in detail in this report. Actual layout of the underground and design of the experiments will depend on the geology of the site selected for DUSEL. Note: Although a specific location is indicated for experiments on ‘Transparent Earth’, most of the experiments also will involve measurement and observation techniqu...
Proceedings of Conference on Drilling and Rock Mechanics, 1965
Engineering Geology, 1972
Testing machines have become increasingly sophisticated and versatile since they were first intro... more Testing machines have become increasingly sophisticated and versatile since they were first introduced in the early eighteenth century. Two recent advances in testing machine technology are of particular importance for laboratory studies of rock failure: the development of machines with stiff frames and the use of feedback control systems. Force has been traditionally regarded as the independent variable in materials testing but the inevitable outcome of a rock mechanics test with a constant loading rate is violent uncontrolled failure at the peak of the force-displacement curve. Rock failure can be controlled if displacement is regarded as the independent variable and a constant displacement rate can be achieved in a testing machine with a stiff frame or a feedback control system. This review contains a brief history of testing machines and a detailed discussion of the principles involved in controlling rock failure with stiff and servtycontrolled testing machines. The development of stiff testing machines is followed from 1935 to the present day and the rock specimen stiffness and testing machine stiffness (factors that are neither fixed nor independent) are discussed in detail. In a closed-loop servo-controlled testing machine, the ability to control rock failure is governed by the fast response time and correct choice of feedback signal. These factors are explained and examples are given of the precise control that can now be achieved in experimental studies of rock failure that were impractical or impossible several years ago.
Rock Mechanics Felsmechanik Mecanique des Roches, 1972
Controlled Failure of Hollow Rock Cylinders in Uniaxial Compression. Detailed consideration is gi... more Controlled Failure of Hollow Rock Cylinders in Uniaxial Compression. Detailed consideration is given to the behavior of hollow rock cylinders loaded in uniaxial compression. Elastic stress distributions calculated by the finite element method show that radial stresses are considerably lower in hollow than in solid cylinders, and that the uniformity of the stresses can be improved considerably by using loading platens having the same cross-section as the specimen. Servo-controlled uniaxial compression tests carried out on solid and thick-walled cylinders of white Tennessee marble show no essential differences in the behavior of the two specimen types with similar strengths and fracture phenomena being observed. In tests carried out in servo-controlled, stiff, and conventional machines, the progressive formation of large numbers of short subaxial cracks is followed by the development of macrofractures such as slabbing and shearing well past the peak of the stress-strain curve. Der gesteuerte Bruch hohler Gesteinszylinder unter einachsigem Druck. Das Verhalten hohler Gesteinszylinder unter einachsigem Druck ist eingehend beschrieben. Die Methode der endlichen Elemente erm6glicht die Berechnung der elastischen Spannungsverteilung und zeigt, dat~ die radialen Spannungen im Hohlzylinder bedeutend geringer sind als im massiven. Der Gebrauch von Druckplatten yore gleichen Querschnitt wie dem der Probe verbessert die Gleichf6rmigkeit der Spsnnungen wesentlich. Servo-gesteuerte einachsige Druckversuche an dichtwandigen hohlen und an massiven Proben yon weif~em Tennessee-Marmot lassen keine wesentlichen Unterschiede zwischen dem Verhalten der beiden Probenarten erkennen. Abnliche Festigkeiten und Brucherscheinungen sind im hohlen und massiven Zylinder beobachtet worden. In Versuchen mit servo-gesteuerten starren und in konventionellen
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1984
The theoretical background of the method is outlined for both the porous-permeable and nonporous ... more The theoretical background of the method is outlined for both the porous-permeable and nonporous cases in isotropic rocks. It is found that, whereas no parameters of the rocks are required for the nonporous case, 3 poro-elastic constants must be known in dealing with porous formations. Laboratory tests on isotropic materials show that the method is reliable for determining both the exact orientation of the principal stresses and their magnitude. Whereas the method may be used successfully in elastic isotropic rock where the largest principal compressive stress is parallel to the axis of the borehole, it may prove less informative when this is not the case. If the method is employed in a mine tunnel, the necessary boreholes could be drilled in both horizontal and vertical directions and the principal stresses determined in all cases.
Journal of the Japanese Association for Petroleum Technology
Tunnelling and Underground Space Technology
Fall Meeting of the Society of Petroleum Engineers of AIME, 1970
Journal of Petroleum Technology, 1969
... The platen also served as a chan-nel for the pressurizing fluid flowingtoward the verti-cal c... more ... The platen also served as a chan-nel for the pressurizing fluid flowingtoward the verti-cal central hole. The loading system for the cylindrical samples was a pressure jacket shnilar to that described by Obert.'z The specimen (5.0 in. in diameter, 6.0 in. ...
A summary of the Earth Science Workshop, Lead, South Dakota, October 4-7 2001, on the planned dev... more A summary of the Earth Science Workshop, Lead, South Dakota, October 4-7 2001, on the planned development of earth science research at the proposed National Underground Science Laboratory (NUSL) will be presented. The Homestake Mine in South Dakota will cease gold production in 2002. The Mine has been recommended for conversion into a NUSL by a national underground science committee and is the focus of a major (physics) proposal to the National Science Foundation. The Earth Science Workshop, associated with the Conference on Underground Science, was held to discuss the type of studies that could be conducted in the Mine and associated practical aspects such as space and time requirements. Construction of the NUSL (estimated to take approximately five years) will involve a variety of rock mechanics and geotechnical studies necessary for the design and excavation of large test chambers at depth for physics experiments, extension of access drifts, and enlargement and deepening of the Y...
One of the main functions of rock mechanics research has been to find ways of determining in situ... more One of the main functions of rock mechanics research has been to find ways of determining in situ stresses. Most methods usually employ some instrumentation for the purpose of measuring hole deformation. The method of hydraulic fracturing has been suggested, because it has been shown that the recorded pressures can be theoretically related to magnitudes of the principal in situ stresses; the orientation of the fracture can often be used to determine the direction of the principal stresses. The advantage of hydraulic fracturing over the present in situ stress determination methods is simplicity: no sophisticated instrumentation is required inside the borehole; hence, the stresses can be measured at any depth. If the formation is impermeable to the fracturing fluid, no elastic constants of the rock are required in calculating the stresses, a factor that not only simplifies the problem, but renders the results more reliable. The theoretical considerations are discussed. A laboratory ex...
Trends in Rock Mechanics, 2000
SPE Drilling and Rock Mechanics Conference, 1973