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Anisotropy and Stress Path Effects in Clays.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Anisotropy and Stress Path Effects in Clays./
Author:	Sivakugan, Nagaratnam.
Description:	1 online resource (222 pages)
Notes:	Source: Dissertations Abstracts International, Volume: 48-07, Section: B.
Contained By:	Dissertations Abstracts International48-07B.
Subject:	Civil engineering. -
Online resource:	click for full text (PQDT)
ISBN:	9798207149639

Anisotropy and Stress Path Effects in Clays.
Sivakugan, Nagaratnam.

Anisotropy and Stress Path Effects in Clays. - 1 online resource (222 pages)

Source: Dissertations Abstracts International, Volume: 48-07, Section: B.

Thesis (Ph.D.)--Purdue University, 1987.

Includes bibliographical references

Anisotropy and stress path are two major factors requiring attention in laboratory and in situ testing. In the research reported herein, experimental and theoretical studies were made on these two factors. Experiments were performed in a servo-controlled cuboidal shear device, and analytical studies were based on the Cam Clay and the modified Cam Clay models. When implications of the findings made in this dissertation are discussed, emphasis is given to pressuremeter testing where anisotropy and stress path play a role. However, the results are of a general nature, and apply to other problems as well. Stress anisotropy in consolidation was studied analytically. A simple procedure was developed to predict the in situ or Ko undrained shear strength from the results of ordinary CIUC tests. The procedure was validated with published experimental data on 24 different soils. To model the in situ behavior of clays, the critical state models, Cam Clay and modified Cam Clay models, were extended to consider the Ko consolidated initial state. A new state parameter, spacing ratio, was introduced to simplify the analysis. Expressions were developed for undrained shear strength and for Skempton's A-parameter at failure. Plane strain conditions are often assumed in the interpretation of pressuremeter test results in clays. Variation of principal stresses during plane strain compression were studied using the modified Cam Clay model. It was shown that σ2/(σ1+σ3) steadily increases, but only slightly, during plane strain compression, which is in agreement with previous experimental results. For practical purposes it is a good approximation to assume that σ2/(σ1+σ3) is a constant throughout plane strain compression loading. A cuboidal shear device with automatic data acquisition system and servo control, a slurry consolidometer, and appurtenent components were developed. Isotropically or anisotropically consolidated cubical specimens were loaded horizontally or vertically under undrained conditions. A significantly larger Φ1 was observed when the loading was horizontal in direction. Thus, in practice it is necessary to use the value of Φ1 appropriate to the direction of field loading.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2024

Mode of access: World Wide Web

ISBN: 9798207149639Subjects--Topical Terms:

561339
Civil engineering.
Index Terms--Genre/Form:

554714
Electronic books.

Anisotropy and Stress Path Effects in Clays.
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100 1 $a Sivakugan, Nagaratnam. $3 1104146
245 1 0 $a Anisotropy and Stress Path Effects in Clays.
264 0 $c 1987
300 $a 1 online resource (222 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
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500 $a Source: Dissertations Abstracts International, Volume: 48-07, Section: B.
500 $a Publisher info.: Dissertation/Thesis.
502 $a Thesis (Ph.D.)--Purdue University, 1987.
504 $a Includes bibliographical references
520 $a Anisotropy and stress path are two major factors requiring attention in laboratory and in situ testing. In the research reported herein, experimental and theoretical studies were made on these two factors. Experiments were performed in a servo-controlled cuboidal shear device, and analytical studies were based on the Cam Clay and the modified Cam Clay models. When implications of the findings made in this dissertation are discussed, emphasis is given to pressuremeter testing where anisotropy and stress path play a role. However, the results are of a general nature, and apply to other problems as well. Stress anisotropy in consolidation was studied analytically. A simple procedure was developed to predict the in situ or Ko undrained shear strength from the results of ordinary CIUC tests. The procedure was validated with published experimental data on 24 different soils. To model the in situ behavior of clays, the critical state models, Cam Clay and modified Cam Clay models, were extended to consider the Ko consolidated initial state. A new state parameter, spacing ratio, was introduced to simplify the analysis. Expressions were developed for undrained shear strength and for Skempton's A-parameter at failure. Plane strain conditions are often assumed in the interpretation of pressuremeter test results in clays. Variation of principal stresses during plane strain compression were studied using the modified Cam Clay model. It was shown that σ2/(σ1+σ3) steadily increases, but only slightly, during plane strain compression, which is in agreement with previous experimental results. For practical purposes it is a good approximation to assume that σ2/(σ1+σ3) is a constant throughout plane strain compression loading. A cuboidal shear device with automatic data acquisition system and servo control, a slurry consolidometer, and appurtenent components were developed. Isotropically or anisotropically consolidated cubical specimens were loaded horizontally or vertically under undrained conditions. A significantly larger Φ1 was observed when the loading was horizontal in direction. Thus, in practice it is necessary to use the value of Φ1 appropriate to the direction of field loading.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2024
538 $a Mode of access: World Wide Web
650 4 $a Civil engineering. $3 561339
655 7 $a Electronic books. $2 local $3 554714
690 $a 0543
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a Purdue University. $3 1184550
773 0 $t Dissertations Abstracts International $g 48-07B.
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=8729797 $z click for full text (PQDT)