Journal of Seismology and Earthquake Engineering

Journal of Seismology and Earthquake Engineering

Effects of Specimen Saturation on Strength Reduction in Triaxial Tests: Monotonic and Cyclic Case Studies

Document Type : Research Article

Authors
Javad Jalili 1
Mojtaba Moosavi 1
Hossein Jahankhah 1
Mohammad Kazem Jafari 2
1 Assistant Professor, Geotechnical Research Center, International Institute of Earthquake Engineering and Seismology(IIEES), Tehran, Iran
2 Professor, Earthquake Risk Management Research Center, International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, Iran
10.48303/jsee.2022.1973963.1037
Abstract
Degree of saturation of soil is an important factor in preparing specimens of soil in the laboratory. The moisture content of the specimen affects its behavior, especially in undrained loading, either by change of the structure of soil or by change of effective stress path. Even though special equipment is required to measure the change of unsaturated specimen’s geometry, they are not provided in many engineering laboratories due to economic and technical reasons. One alternative for a precise measurement is to saturate the specimens. We show herein that apart from such expensive measurements and saturating the specimens even though it is not saturated in the field, estimating the change of specimen size by simplifying the relevant assumptions and resembling the degree of saturation of the field in the laboratory is to be preferred. Two case studies of monotonic and cyclic triaxial tests are reported herein to show this priority based on field tests and image processing results. It is concluded that given the variation of the degree of saturation of the soil in the field, as well as its volumetric behavior while being sheared, that is, either being compressional or dilative, are essential to make the optimal decision on the selection of the proper degree of saturation at the laboratory.
Keywords
Degree of Saturation
UU Triaxial Tests
Unsaturated Specimen
Cyclic Loading
Compressional Behavior
Dilative Behavior

Subjects

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Journal of Seismology and Earthquake Engineering
Volume 23, Issue 1
Winter 2021
Pages 9-18

  • Receive Date 21 November 2022
  • Revise Date 18 December 2022
  • Accept Date 20 December 2022
  • Publish Date 01 January 2021