Abstract
Porosity change is a common characteristic of natural soils in fluid-solid interaction problems, which can lead to an obvious change of the soil-water retention curve (SWRC). The influence of porosity on soil water retention phenomena is investigated by a theoretical model and an experimental test in this study. A model expressing the change in suction with porosity and effective saturation is put forward theoretically. The model is based on an idealization of three-phase porous materials, the pore structures of which are homogeneous and isotropic. It accounts for the porosity effect on soil water retention, using four parameters with clear physical meanings. The presented model can obtain the SWRC at any porosity, which will reduce the test number required in characterizing the hydraulic behavior of soil. A laboratory experiment for loamy sand with different porosities is performed. The test results show that suction has a significant variation with changes in porosity and decreases with the increase of porosity. The formulation is verified by both the test data and the literature data for FEBEX bentonite and Boom clay. The very good agreements between measured and predicted results show that the SWRC model is reliable and feasible for various soils.
Highlights
The soil-water retention curve (SWRC) is defined as the relationship between matric suction and the degree of saturation in unsaturated soils
The unit of d1 is N/m2, and the other parameters are dimensionless. d2 is connected to pore density and related to porosity. d3 represents the combined effect of temperature, hysteresis effects, and other factors, and d4 is only related to porosity
A SWRC model is proposed, where suction is expressed as a function of porosity and effective saturation
Summary
The soil-water retention curve (SWRC) is defined as the relationship between matric suction and the degree of saturation in unsaturated soils. A variation in soil porosity is common in fluid-solid interaction problems [3, 4], and this change will result in an obvious change of SWRC [5] Sometimes, it needs to predict the SWRCs for soil with different porosities. Various SWRC models have been proposed to take the influence of porosity into account by relating suction and/or the pore size distribution index to void ratio or density. A SWRC model accounting for the effect of porosity is presented, assuming the unsaturated soil as a continuous, isotropic, and homogeneous three-phase pore mixture. This equation is expressed by a law of effective saturation, suction, and porosity, with only four parameters. The proposed model is verified by the test data for loamy sand with different porosities, as well as the literature data for FEBEX bentonite and Boom clay
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
