Analysis of the Oedometer Test Results using a New Method


The oedometer test, which represents the in situ stress conditions (typically called k0 conditions), is one of the most important geotechnical engineering laboratory tests. For any geotechnical engineering application, k0 is often used to calculate the lateral stress of the at-rest stress state. Most of the existing analytical expressions for k0 suffer one or more of the following limitations: (1) they have unrealistic assumptions; (2) k0 was derived as a constant value for the very high stress state, but implicitly applied to the whole stress range; (3) k0 equation is often implicit and complicated. In this paper, a new method is used for the data analysis and prediction of k0 value, which overcomes all of these limitations and was derived upon the definition of k0 condition without any additional assumption. In addition, the expression can be adopted for any critical state constitutive model for saturated soils. The modified Cam clay model was used to demonstrate the application of the proposed expression. Using this new method, the lateral stresses can be calculated for the oedometer test, and therefore, the stress paths are predicted and compared with the available methods. For verification purposes, the lateral strain increments are predicted and compared to zero. Finally, to check the accuracy of the new method, the predicted void ratio using the new method are compared to the experimental results in the v-logσv′ plane. A good agreement is reached between the measured and predicted specific volumes. Calculations indicated that a coefficient of determination greater than 99% is reached between the measured and predicted void ratios.

Meeting Name

Geo-Congress 2020: Modeling, Geomaterials, and Site Characterization (2020: Feb. 25-28, Minneapolis, MN)


Civil, Architectural and Environmental Engineering

Research Center/Lab(s)

Center for Research in Energy and Environment (CREE)

Keywords and Phrases

At-Rest Coefficient; Constitutive Modeling; Elastoplastic; Modified Cam Clay Model; Oedometer Test; Stress Path

International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version


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© 2020 American Society of Civil Engineers (ASCE), All rights reserved.

Publication Date

01 Feb 2020