A Flexible Model for Moisture-Suction Relationship for Unsaturated Soils and Its Application

Nadarajah Ravichandran, Shada H. Krishnapillai

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DOI: 10.4236/ijg.2011.23022                

Abstract

The mathematical equation for the moisture-suction relationship also known as soil water characteristic curve (SWCC) is one of the constitutive relations necessary for the computational modeling of deformation and flow problems of unsaturated soil using the finite element method. In this paper, a new empirical equa-tion for the SWCC is developed that incorporates the actual airentry suction and the maximum possible suction of the soil as input parameters. The capability of the new model is investigated by fitting the experimental data for twelve different soils that includes sands, silts, and clays. The model fits the experimental data well including in high suction range which is one of the difficulties observed in other commonly used models such as the Brooks and Corey, van Genuchten, and Fredlund and Xing models. The numerical stability and the performance of the new model at low and high degrees of saturations in finite element simulation are investigated by simulating the dynamic response of a compacted embankment and the results are compared with similar predictions made using widely used SWCC models.

Keywords

Soil-Water Characteristic Curve, Unsaturated Soils, SWCC for Low Degree of Saturation, Moisture-Suction Relationship, Comparison of Soil-Water Characteristic Curves

Conflicts of Interest

The authors declare no conflicts of interest.

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