CUED Publications database

Strength mobilization in clays and silts

Vardanega, PJ and Bolton, MD (2011) Strength mobilization in clays and silts. Canadian Geotechnical Journal, 48. pp. 1485-1503. ISSN 0008-3674

Full text not available from this repository.

Abstract

A large database of 115 triaxial, direct simple shear, and cyclic tests on 19 clays and silts is presented and analysed to develop an empirical framework for the prediction of the mobilization of the undrained shear strength, c u, of natural clays tested from an initially isotropic state of stress. The strain at half the peak undrained strength (γM=2) is used to normalize the shear strain data between mobilized strengths of 0.2c u and 0.8c u. A power law with an exponent of 0.6 is found to describe all the normalized data within a strain factor of 1.75 when a representative sample provides a value for γM=2. Multi-linear regression analysis shows that γM=2 is a function of c u, plasticity index I p, and initial mean effective stress p′ 0. Of the 97 stress-strain curves for which c u, I p, and p′ 0 were available, the observed values of γM=2 fell within a factor of three of the regression; this additional uncertainty should be acknowledged if a designer wished to limit immediate foundation settlements on the basis of an undrained strength profile and the plasticity index of the clay. The influence of stress history is also discussed. The application of these stress-strain relations to serviceability design calculations is portrayed through a worked example. The implications for geotechnical decision-making and codes of practice are considered.

Item Type: Article
Uncontrolled Keywords: Clays Correlation and normalization Mobilized strength Silts
Subjects: UNSPECIFIED
Divisions: Div D > Geotechnical and Environmental
Div D > Construction Engineering
Depositing User: Cron Job
Date Deposited: 07 Mar 2014 11:26
Last Modified: 08 Dec 2014 02:33
DOI: 10.1139/t11-052