Masters Theses

Abstract

"When coal is extracted by the long wall mining method, two gate-roads on either side of the working face are driven with the advancing operation. In the surroundings of these openings the state of stress which existed prior to mining is not only disturbed by the drifting process of the gate-roads but also by the coal extraction in the long wall, resulting in an "unsymmetrical" stress distribution. Varying incremental pressure components and the high complexity of strata movements make it extremely difficult to control the rock behavior under unsymmetrical conditions by conventional support. Application of roof bolts as an auxiliary support can improve the control of the strata surrounding long wall gate-roads.

To indicate the qualitative effect of roof bolts on the stress distribution around underground openings in stratified rock under unsymmetrical loading conditions, composite models made of photo-elastic material were tested in a 6 ft. diameter centrifuge, providing proper loading conditions. Stress distributions were permanently "frozen" into the models while under load.

Test results indicate that the high shearing stresses which occur near the rigid abutment of the long wall gate-road and the bending stresses in the roof beams can be reduced considerably by the application of roof bolts in proper pattern arrangements.

Since this study was concerned with the development of an experimental technique and simple structural conditions were chosen, an extension of this investigation to more complicated conditions is possible"--Abstract, page i.

Advisor(s)

Caudle, Rodney D.

Committee Member(s)

Morgan, Ray E., 1908-1997
Davidson, Robert F., 1911-1971
Clark, George Bromley, 1912-

Department(s)

Mining Engineering

Degree Name

M.S. in Mining Engineering

Comments

In the original manuscript, some pages are out of order. The order has been corrected in the pdf included here.

Publisher

Missouri School of Mines and Metallurgy

Publication Date

1962

Pagination

xi, 102, R6 pages

Note about bibliography

Includes bibliographical references (pages R1-R5)

Rights

© 1962 Friedrich H. K. Esser, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 1419

Print OCLC #

5948882

Electronic OCLC #

1048008189

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