Compressive strength and failure modes of lithophysae-rich Topopah Spring tuff specimens and analog models containing cavities

Authors

Nick Hudyma, University of North FloridaFollow
B. Burcin Avar, MACTEC Engineering and ConsultingFollow
Moses Karakouzian, University of Nevada, Las VegasFollow

Document Type

Article

Publication Date

5-2004

Publication Title

Engineering Geology

Volume

73

Issue

1-2

First page number:

179

Last page number:

190

Abstract

The presence of lithophysae in some units of Topopah Spring Tuff at Yucca Mountain, Nevada, the U.S. high level nuclear waste repository, have a detrimental effect on the engineering properties of the rock mass and its performance. The lithophysae were formed by pockets of gas trapped within the falling volcanic ash that formed the tuff units. The porosity associated with the lithophysae is termed macroporosity because of the large pore size as compared with traditional rock pores. In this paper, lithophysae-rich tuff and analog models (both cylindrical and cubic) made of plaster of Paris containing artificially created cavities were tested to assess the effect of macroporosity on both the uniaxial compressive strength and failure modes of the specimens. As expected, compressive strength decreases with increasing porosity due to lithophysae in tuff and cavities in plaster analog specimens. Failure modes of cylindrical specimens were also investigated. The failure modes observed were grouped into four distinct categories: spalling, axial splitting, shear failure and web failure. The failure modes transition from spalling through web failure as the percentage of macroporosity within the specimen increased.

Keywords

Failure mode and effects analysis; Materials--Compression testing; Porosity; Volcanic ash; tuff; etc.

Disciplines

Civil and Environmental Engineering | Environmental Engineering | Environmental Sciences | Geotechnical Engineering | Mechanics of Materials | Other Materials Science and Engineering | Sedimentology

Language

English

Permissions

Use Find in Your Library, contact the author, or interlibrary loan to garner a copy of the item. Publisher policy does not allow archiving the final published version. If a post-print (author's peer-reviewed manuscript) is allowed and available, or publisher policy changes, the item will be deposited.

Repository Citation

Hudyma, N., Avar, B. B., Karakouzian, M. (2004). Compressive strength and failure modes of lithophysae-rich Topopah Spring tuff specimens and analog models containing cavities. Engineering Geology, 73(1-2), 179-190.
http://dx.doi.org/10.1016/j.enggeo.2004.01.004