Masters Theses

Abstract

"Stress distribution around a pilot hole during overcoring was investigated. A study of axial strain on the borehole surface was undertaken. Two-dimensional epoxy resin models were prepared and stress frozen in a centrifuge. The stress-frozen models were examined under a direct-viewing polariscope. The magnitude of axial strain and the effect of strain relaxation on the pilot hole were measured on blocks of brittle materials. Factors contributing to discing of core during the overcoring operation were investigated and a mechanism of failure postulated. The loading conditions simulating in situ, core and bit pressures were applied individually to the brittle models and axial strain readings were noted. Axial strain was found to be at a significant value and radical differences in stress levels were found within the overcored zone"--Abstract, page i.

Advisor(s)

Scott, James J.

Committee Member(s)

Beveridge, Thomas R. (Thomas Robinson), 1918-1978
Spokes, Ernest M., 1916-1995
Parry, Myron G.

Department(s)

Mining Engineering

Degree Name

M.S. in Mining Engineering

Publisher

University of Missouri at Rolla

Publication Date

1966

Pagination

vi, 75 pages

Note about bibliography

Includes bibliographical references (pages 56-60).

Rights

© 1966 Varakantham Sreedhar Reddy, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Stress concentrationStrain gagesCore drillingRock mechanics -- Mathematical models

Thesis Number

T 1870

Print OCLC #

5973520

Electronic OCLC #

896879057

Download

Share

 
COinS