Masters Theses

Keywords and Phrases

Consolidated undrained triaxial compression test for cohesive soils (CU test)


"A considerable amount of research has been conducted on the strength of both clays and sands while the research conducted on low plasticity silt has been very limited. The objective of this study was to evaluate the undrained behavior of monotonically loaded low plasticity silt. The well understood stress-strain behavior of sand-like and clay-like soils was compared to the behavior of low plasticity silts. In particular, failure conditions and the steady state behavior of low plasticity silt were compared to the conditions seen in sand-like and clay-like soils.

The soil used in the study program was obtained from the Mississippi River Valley and consisted of modified loessial silt deposits with a plasticity index of about 6. In order to achieve a soil fabric similar to its natural deposition samples were consolidated from slurry using a consolidometer. To ensure minimum sample disturbance, special thin-walled shelby tubes were designed and constructed.

The effects of the initial density, confinement pressure, and overconsolidation ratio were evaluated in a triaxial testing program. A strong dilative behavior similar to that of sandy soils was observed. This dilative behavior continued until the silt specimens exited their saturation state, which caused the pore water pressure to be constant and show apparent steady state behavior due to the compressibility of air.

Although steady state was not observed in the tested silt, the limit between the initial contraction and dilation was clearly located and quantified. Phase transformation of the low plasticity silt was observed at an overconsolidation ratio of about 2"--Abstract, page iii.


Stephenson, Richard Wesley

Committee Member(s)

Luna, Ronaldo
Rogers, J. David


Civil, Architectural and Environmental Engineering

Degree Name

M.S. in Civil Engineering


United States. Bureau of Reclamation


University of Missouri--Rolla

Publication Date

Fall 2006


xii, 82 pages

Note about bibliography

Includes bibliographical references (pages 80-81).

Geographic Coverage

Mississippi River Valley


© 2006 Ali Mohammad Izadi, All rights reserved.

Document Type

Thesis - Restricted Access

File Type




Subject Headings

Materials -- Compression testing
Shear strength of soils -- Testing

Thesis Number

T 9099

Print OCLC #


Electronic OCLC #


Link to Catalog Record

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