Location

St. Louis, Missouri

Session Start Date

4-26-1981

Session End Date

5-3-1981

Abstract

Cylindrical cyclic loading tests were used to study the effects of time dependent stress path on the plastic and elastic deformations of sand and clay soil samples. The test materials were obtained from the subgrade of existing highway pavements located throughout the state of Michigan. Approximately, 25 cylindrical soil samples (13.5 cm long, 5.5 cm in diameter) were tested under repeated loading conditions using different hydrostatic confining pressures and several time dependent stress-paths. In all tests, the first invariant of the stress tensor was cycled between two constant values and the first invariant of the stress deviator tensor was increased incremently and cycled such that its minimum value was kept greater than 6.895 kPa. at all times. Analysis of the test results indicated several findings, these include: 1) Increasing the first invariant of the stress deviator tensor with time,for sand samples, decreased the average rate and magnitude of the plastic deformation of the samples. 2) For clay samples, the rate and magnitude of the plastic and elastic deformations were found to be dependent on the first invariants of the stress tensor and stress deviator tensor, on the stresspath and on the sample parameters. For example, the elastic strains of two duplicate soil samples tested under the same stress conditions (same invariants of stress tensor and stress deviator tensor) were different by a factor of 2 to 100. The value of this factor was found to be a function of the time dependent stress path.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Meeting Name

First Conference

Publisher

University of Missouri--Rolla

Publication Date

4-26-1981

Document Version

Final Version

Rights

© 1981 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Apr 26th, 12:00 AM May 3rd, 12:00 AM

The Effects of Time Dependent Stress-Path on The Plastic and Elastic Deformation of Sand and Clay Soils Subjected to Dynamic Loading

St. Louis, Missouri

Cylindrical cyclic loading tests were used to study the effects of time dependent stress path on the plastic and elastic deformations of sand and clay soil samples. The test materials were obtained from the subgrade of existing highway pavements located throughout the state of Michigan. Approximately, 25 cylindrical soil samples (13.5 cm long, 5.5 cm in diameter) were tested under repeated loading conditions using different hydrostatic confining pressures and several time dependent stress-paths. In all tests, the first invariant of the stress tensor was cycled between two constant values and the first invariant of the stress deviator tensor was increased incremently and cycled such that its minimum value was kept greater than 6.895 kPa. at all times. Analysis of the test results indicated several findings, these include: 1) Increasing the first invariant of the stress deviator tensor with time,for sand samples, decreased the average rate and magnitude of the plastic deformation of the samples. 2) For clay samples, the rate and magnitude of the plastic and elastic deformations were found to be dependent on the first invariants of the stress tensor and stress deviator tensor, on the stresspath and on the sample parameters. For example, the elastic strains of two duplicate soil samples tested under the same stress conditions (same invariants of stress tensor and stress deviator tensor) were different by a factor of 2 to 100. The value of this factor was found to be a function of the time dependent stress path.