In Situ Strength Measurements of Weak Rocks
Publication: Journal of Geotechnical Engineering
Volume 117, Issue 9
Abstract
There is a lack of strength data on weak rocks where cores for conventional testing can only be obtained with difficulty. In recent investigations, strengths are obtained over a 300-ft (91-m) vertical section for calcareous fanglomerates, typical of the Southwestern United States, by plate testing and correlation with seismic velocity measurements. A 240-ton (213-metric ton) ore truck is used to provide the large reaction load necessary to induce failure. Values for the compressive strength are computed from Boussinesq stresses, Mohr circle analysis, and by correlation with P-wave velocity, and range from 451 psi (3.1 MPa) at a depth of 100 ft (61 m) to 863 psi (5.6 MPa) at a depth of 300 ft (122 m). Interpretation of the results of the plate tests provides an interesting example of the different engineering approaches sometimes needed in rock and soil mechanics. Both the plate tests and seismic correlations give similar results and, when used with care, represent simple and reliable methods for strength estimation.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Beckwith, G. H., and Hansen, L. A. (1982). “Calcareous soils of the southwestern United States.” Special Technical Publication 777, ASTM, Philadelphia, Penn., 16–35.
2.
Burmister, D. (1963). “Prototype load‐bearing tests for foundations of structures and pavements.” Special Technical Publication 322, ASTM, 98–119.
3.
Cummings, R., Salhaney, L., Zeihen, G., Armstrong, R., Daemen, J., Farmer, I., Glynn, M., Mojtabai, N., Sternberg, B., DeNatale, J., Nowatzki, E., Reynolds, S., Welty, J., and Brooks, S. (1987). “Summary report of geotechnical investigations; 9/86 through 2/88; Maricopa Superconducting Super Collider Site; Maricopa County, Arizona.” Open File Report 87‐6, Arizona Bureau of Geology and Mineral Technology, Arizona.
4.
Deere, D. U., and Miller, R. P. (1966). “Engineering classification and index properties for intact rock.” AFWL‐TR‐65‐16, Air Force Weapons Lab., Kirkland, N.M.
5.
Hobbs, N. (1974). “The prediction of settlement of structure on rock.” Conference on settlement of structures, Pentech Press, London, England, 579–610.
6.
Jaeger, J. C., and Cook, N. G. W. (1979). Fundamentals of rock mechanics, 3rd Ed., Chapman and Hall, London, England.
7.
Judd, W. R., and Huber, C. (1961). “Correlation of rock properties by statistical methods.” Int. Symp. on Mining Res., Pergamon, Oxford, England.
8.
Nelson, C. R., Peterson, D. L., and Nelson, B. K. (1987). “Tunnel construction in very weak sandstone.” Proc. Rapid Excavation and Tunnelling Conference, New Orleans, v. 1, 21–27.
9.
Osterberg, J. (1947). “Load tests of bearing capacity of soils, discussion.” Special Technical Publication 79, American Soc. for Testing and Materials.
10.
Seegmiller, B. (1970). “Twin Buttes slope stability: Slope design analysis and recommendations for the alluvium in the northeast pit area.” Mining Res. Dept. Report, Anaconda Co., Tucson, Ariz.
11.
Singh, A. (1981). “Soil engineering in theory and practice.” Geotechnical testing and instrumentation, II, APT Books, Inc., New York, N.Y.
12.
“Standard test method for bearing capacity of soil for static load on spread footings.” (1972). ASTM D1194, American Soc. for Testing and Materials, 257–259.
13.
Terzaghi, K. (1943). Theoretical soil mechanics. John Wiley and Sons, Inc., New York, N.Y.
14.
Timoshenko, S., and Goodier, J. (1951). Theory of elasticity. McGraw‐Hill Book Co., New York, N.Y.
Information & Authors
Information
Published In
Copyright
Copyright © 1991 ASCE.
History
Published online: Sep 1, 1991
Published in print: Sep 1991
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.