Techno Press
You logged in as Techno Press

Geomechanics and Engineering
  Volume 32, Number 1, January10 2023 , pages 97-110
DOI: https://doi.org/10.12989/gae.2023.32.1.097
 


Measurement of Ko and Ko' during loading and unloading of loose sand
Shay Nachum, Mark Talesnick and Sam Frydman

 
Abstract
    The coefficient of lateral earth pressure at rest in loose sand during virgin loading, Ko, and during unloading, Ko, have been determined from laterally confined load-unload tests. The tests included measurement of lateral pressure with null pressure gauges, side wall friction with newly designed friction meters and applied pressure and base pressure with load cells. The importance of accounting for side-wall friction when evaluating the distribution of vertical pressure over the height of the soil specimen was demonstrated. Relatively uniform friction was observed during loading, but this was not the case during unloading unless friction reduction measures were employed. While the measured value of Ko was found to be close to, if slightly higher than the value commonly estimated on the basis of friction angle, o, the ratio of Ko, to Ko was found to reasonably fit an expression of the form Ko Ko⁄=1+C∙log (OCR), with C equal to 1 in the present tests.
 
Key Words
    𝐾0; confined loading; confined unloading; loose sand; side-wall friction
 
Address
Shay Nachum, Mark Talesnick and Sam Frydman: Faculty of Civil & Environmental Engineering, Technion – Israel Institute of Technology, Haifa, 32000, Israel
 

Techno-Press: Publishers of international journals and conference proceedings.       Copyright © 2024 Techno Press
P.O. Box 33, Yuseong, Daejeon 305-600 Korea, Tel: +82-42-828-7996, Fax : +82-42-828-7997, Email: admin@techno-press.com