Overcoring Equipment and Techniques

Overcoring Equipment and Techniques

Author: Verne E. Hooker

Publisher:

Published: 1974

Total Pages: 0

ISBN-13:

DOWNLOAD EBOOK

The U.S. Bureau of Mines' three-component borehole deformation gage that has all elements in the same plane is designed to measure diametral deformations of a 1-1/2 inch borehole during stress relief from overcoring with a 6-inch overcoring diamond drill bit. Each overcore provides sufficient information to calculate the secondary principal stresses and orientation for the plane of measurement. If measurements are obtained from at least three holes, a three-dimensional representation of the average ground stress components can be determined.


Rock Stress and Its Measurement

Rock Stress and Its Measurement

Author: B. Amadei

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 524

ISBN-13: 9401153469

DOWNLOAD EBOOK

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.