Rainfall-induced differential settlements of foundations on heterogeneous unsaturated soils

Le, T.M.H., Gallipoli, D., Sanchez, M. and Wheeler, S. (2013) Rainfall-induced differential settlements of foundations on heterogeneous unsaturated soils. Geotechnique, 63(15), pp. 1346-1355. (doi: 10.1680/geot.12.P.181)

Abstract

This study stochastically investigates the rainfall-induced differential settlement of a centrally loaded, rigid strip foundation on an unsaturated soil with spatially varying values of either preconsolidation stress or porosity. The differential settlement (between the two foundation ends) is calculated at various times during rainfall by way of a coupled, hydro-mechanical, finite-element analysis. The Barcelona basic model describes the mechanical behaviour of the soil, and the van Genuchten relationships describe water retention and permeability. The variability of soil properties is modelled by means of random fields with spatial correlation in the framework of a Monte Carlo simulation. The study demonstrates that the occurrence of rainfall-induced differential settlements can be consistently analysed using concepts of unsaturated soil mechanics and random field theory. Results show that differential settlements can be vastly underpredicted (or even completely missed) if random heterogeneity and partial saturation are not simultaneously considered. The variation of differential settlements and their statistics during the rainfall depend on the magnitude of the applied load and the statistics of soil variability. Moreover, the transient phase of infiltration and a spatial correlation length equal to the width of the foundation pose the highest risk of differential settlement.

• Item Type: Articles
• Additional Information: Permission is granted by ICE Publishing to print one copy for personal use. Any other use of these PDF files is subject to reprint fees. http://www.icevirtuallibrary.com/content/serial/geot
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Wheeler, Professor Simon
• Authors: Le, T.M.H., Gallipoli, D., Sanchez, M., and Wheeler, S.
• College/School: College of Science and Engineering > School of Engineering > Infrastructure and Environment
• Journal Name: Geotechnique
• Publisher: ICE Publishing
• ISSN: 0016-8505
• ISSN (Online): 1751-7656
• Copyright Holders: Copyright © 2013 ICE Publishing
• First Published: First published in Geotechnique 63(15):1346-1355
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher.