Masters Theses


"Uniaxial compression tests were performed on nine rock types to study the different methods of determining their modulus of elasticity. Variations of the standard tangent and secant methods were used to determine moduli. An analysis of the repeatability of these moduli was conducted.

Six methods of determining moduli are presented in this study. The methods used for analysis are: the tangent modulus taken along the straight line portion of the plot; the tangent modulus at 50% of maximum stress; the secant modulus taken at maximum stress; and the secant modulus at 50% of maximum stress. In addition, the abovementioned secant methods were modified to account for initial system compliance and fissure closing.

For the rocks tested, the most consistent modulus technique was the modified secant modulus, followed by the modified secant modulus at 50% of maximum stress. The secant modulus at 50% maximum stress was the least repeatable method.

Brittle samples experienced less variation in their moduli values. As rock strength decreased, the coefficient of variation of the moduli of a given rock type increased. For example, the two strongest rocks under uniaxial compression also had the lowest coefficient of variation in their moduli values. In contrast, the weakest rock in the study had the highest coefficient of variation--slightly over 17%"--Abstract, page iii.


Stephenson, Richard Wesley
Santi, Paul M. (Paul Michael), 1964-

Committee Member(s)

Lentz, Rodney


Civil, Architectural and Environmental Engineering

Degree Name

M.S. in Civil Engineering


University of Missouri--Rolla

Publication Date

Spring 1998


x, 95 pages

Note about bibliography

Includes bibliographical references (pages 92-94).


© 1998 Jason Edward Holschen, All rights reserved.

Document Type

Thesis - Restricted Access

File Type




Subject Headings

Rock pressure -- Testing
Strains and stresses

Thesis Number

T 7483

Print OCLC #


Electronic OCLC #


Link to Catalog Record

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