Download or read book Measurement of in situ stress in salt and rock using NQR techniques Department of Energy Washington D C written by E. Schempp and published by . This book was released on 1980 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of In situ Stress in Salt and Rock Using NQR Techniques written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A discussion of how stress and strain affect the quantities which can be measured in an NQR experiment shows that, for stresses of the magnitude to be expected at depths up to about 10,000 feet, quadrupole coupling constants will fall in the range of 1 to 10 kHz for both the sodium and chloride ions in NaCl. The most promising system involves pulsed nuclear double resonance detection; and alterative is to observe the quadrupolar splitting of the NMR signal. Choices to be made in the measurement and mapping techniques are discussed. The well-known perturbation of the homogenous stress field in the neighborhood of a borehole is shown to be advantageous from the point of view of obtaining directional information on the stress. Construction and operation of a borehole stress sensor are considered. The NQR technique seems feasible for measuring the magnitude and direction of underground stress with a resolution of about 25 psi, or 2.5% at 1000 psi. Downhole instrumentation suitable for in-situ determinations of stress appears within the state of the art. Additional tasks required on the project are identified.
Download or read book The Measurement of In situ Stress in Salt and Rock Using NQR Techniques written by Ellery Frank Schempp and published by . This book was released on 1980 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of in situ stress in rock using NQR techniques written by E. Schempp and published by . This book was released on 1982 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1982 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rock Stress and Its Measurement written by B. Amadei and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rock masses are initially stressed in their current in situ state of stress and to a lesser natural state. Whether one is interested in the extent on the monitoring of stress change. formation of geological structures (folds, faults, The subject of paleostresses is only briefly intrusions, etc. ), the stability of artificial struc discussed. tures (tunnels, caverns, mines, surface excava The last 30 years have seen a major advance our knowledge and understanding of rock tions, etc. ), or the stability of boreholes, a in the in situ or virgin stress field, stress. A large body of data is now available on knowledge of along with other rock mass properties, is the state of stress in the near surface of the needed in order to predict the response of rock Earth's crust (upper 3-4km of the crust). masses to the disturbance associated with those Various theories have been proposed regarding structures. Stress in rock is usually described the origin of in situ stresses and how gravity, within the context of continuum mechanics. It is tectonics, erosion, lateral straining, rock fabric, defined at a point and is represented by a glaciation and deglaciation, topography, curva second-order Cartesian tensor with six compo ture of the Earth and other active geological nents. Because of its definition, rock stress is an features and processes contribute to the current enigmatic and fictitious quantity creating chal in situ stress field.
Download or read book Electronic Measurement of Rock Stress written by John C. Cook and published by . This book was released on 1973 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the program was to evaluate feasibility of non-destructive electronic measurement (and logging) of rock stress in situ, using atomic resonances that are pressure-sensitive. Nuclear quadrupole resonance (NQR) appeared clearly applicable, since no magnetic aligning field is needed, there are several common NQR-active nuclear species in major rock-forming minerals, and rf magnetic fields between 0.3 and 3 megahertz (the resonant frequencies) propagate well through many rocks. There are also alternative resonance methods which may be applicable, including NMR, EPR, and EFR. A comprehensive literature search has been completed on NQR in minerals, which shows that aluminum-27 and a few other elements in feldspars are promising for NQR measurement of rock stress. Efforts to detect these resonances in mineral specimens were mostly unsuccessful because of their extreme weakness. The outlook for NQR is now considered marginal. Short studies of other rf spectrographic methods showed that ferromagnetic effects cannot be used, but that electron paramagnetic resonance (EPR) holds some promise as a means of measuring rock stress, since strong EPR signals are readily obtained from most rocks. (Author).
Download or read book In situ Rock Stress written by Ming Lu and published by CRC Press. This book was released on 2006 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding in-situ rock stress is important in the exploration and engineering involving rock masses for mining, hydropower, tunneling, oil and gas production, and stone quarrying. Traditional methods of determining these stresses have not developed substantially to keep pace with the increasing utilization of rock masses. Contributed by a group of leading experts, this book addresses new developments in numerical modeling and advanced measuring techniques. The papers in In-Situ Rock Stress: Measurement, Interpretation and Application reflect the development in this field, covering measuring techniques, interpretation methods, and application of the in-situ stress in engineering practice.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1983 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Spectroscopic Properties of Inorganic and Organometallic Compounds written by G Davidson and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spectroscopic Properties of Inorganic and Organometallic Compounds provides a unique source of information on an important area of chemistry. Divided into sections mainly according to the particular spectroscopic technique used, coverage in each volume includes: NMR (with reference to stereochemistry, dynamic systems, paramagnetic complexes, solid state NMR and Groups 13-18); nuclear quadrupole resonance spectroscopy; vibrational spectroscopy of main group and transition element compounds and coordinated ligands; and electron diffraction. Reflecting the growing volume of published work in this field, researchers will find this Specialist Periodical Report an invaluable source of information on current methods and applications. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading experts in their specialist fields, this series is designed to help the chemistry community keep current with the latest developments in their field. Each volume in the series is published either annually or biennially and is a superb reference point for researchers. www.rsc.org/spr
Download or read book In Situ Rock Stress Measurement Interpretation and Application written by Abhinav Mishra and published by . This book was released on 2015-08 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding in-situ rock stress is important in the exploration and engineering involving rock masses for mining, hydropower, tunneling, oil and gas production, and stone quarrying. Traditional methods of determining these stresses have not developed substantially to keep pace with the increasing utilization of rock masses. Contributed by a group of leading experts, this book addresses new developments in numerical modeling and advanced measuring techniques. In-Situ Rock Stress: Measurement, Interpretation and Application reflect the development in this field, covering measuring techniques, interpretation methods, and application of the in-situ stress in engineering practice. Estimate of the in-situ rock stress state can be realized by direct or indirect methods. Although the indirect method has developed rapidly in recent years, the direct field measurement is still by far dominating. Great improvements have been achieved with the 'traditional' field tests by overcoring and hydraulic fracturing, whilst the recently developed methods become matured. In addition, ideas of new methods and new instruments will make the stress estimate easier, less expensive and more reliable.
Download or read book Technical Progress Report for the Quarter written by and published by . This book was released on 1981 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rock Anisotropy and the Theory of Stress Measurements written by Bernard Amadei and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: Any undisturbed rock mass is subject to natural stresses inclu ding gravitational stresses due to the mass of the overburden and possibly tectonic stresses due to the straining of the earth's crust and remanent stresses due to past tectonism. Knowledge of the in situ stress field must be integrated into any rock engineering design along with general rock mass characteristics such as de for mability, strength, permeability and time dependent behavior. For example, the choice of optimum orientation and shape of deep underground caverns or complex underground works will be controlled by the orientation and the magnitude of the in situ stress @ield if it is necessary to minimize stress concentration problems. Long term variation of the in situ stress field may also help to evaluate the potential hazard of earthquake occurences. The magnitude and orientation of the stress field ata point within a rock mass can be measured but there is no known method by which the state of stress at a point can be accurately determined by instruments located remotely. In general, measurements are made inside boreholes, on outcrops or on the internal surfaces of under ground cavities. Most of the measuring techniques intentionally disturb the state of stress in the rock and then measure consequent strains and displacements. Measured strains or displacements are then related to the stresses through assumptions of material behavior. A common procedure is to assume that the rock mass is linearly elastic, isotropic, continuous and homogeneous.
Download or read book A Short Course In modern in Situ Stress Measurement Methods written by and published by . This book was released on 1993 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In Situ Stress Determination in Rock Using the Acoustic Emission Technique written by John Joseph McElroy and published by . This book was released on 1985 with total page 698 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Field Tests of Stress Measurement Techniques in Rock Salt written by John C. Stormont and published by . This book was released on 1984 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comparison of Stress measuring Techniques at the DNA UTP Site Rodgers Hollow Kentucky written by R. E. Finley and published by . This book was released on 1994 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Defense Nuclear Agency (DNA) is developing explosives technology through its Underground Technology Program (UTP). Sandia National Laboratories (SNL) has supported the DNA by conducting research to characterize the in situ stress and rock mass deformability at one of the UTP underground sites at Rodgers Hollow, near Louisville, Kentucky on the Fort Knox Military Reservation. The purpose of SNL's testing was to determine the in situ stress using three different measurement techniques and, if possible, to estimate the rock mass modulus near the underground opening. The three stress-measuring techniques are (1) borehole deformation measurements using overcoring, (2) Anelastic Strain Recovery (ASR) complemented by laboratory ultrasonic and mechanical properties testing, and (3) the in situ flatjack technique using cancellation pressure. Rock mass modulus around the underground opening was estimated using the load deformation history of the flatjack and surrounding rock. Borehole deformation measurements using the overcoring technique probably represent the most reliable method for in situ stress determination in boreholes up to 50 ft (15 m) deep in competent rock around an isolated excavation. The technique is used extensively by the tunneling and mining industries. The ASR technique is also a core-based technique and is used in the petroleum and natural gas industries for characterization of in situ stress from deep boreholes. The flatjack technique has also been used in the tunneling and mining industries, and until recently has been limited to measurement of the stress immediately around the excavation. Results from the flatjack technique must be further analyzed to calculate the in situ stress in the far field.
