A Unified Model for Soil Shrinkage, Subsidence, and Cracking. Issue 3 (23rd March 2016)

• Record Type: Journal Article
• Authors: Stewart, Ryan D.; Rupp, David E.; Abou Najm, Majdi R.; Selker, John S.
• Is Part Of: Vadose zone journal. Volume 15:Issue 3(2016)
• Page Start: 1
• Page End: 15
• Publication Date: 2016-03-23
• Subjects: Soil science -- Periodicals; Zone of aeration -- Periodicals; Groundwater flow -- Periodicals; Groundwater flow; Zone of aeration; Periodicals; Electronic journals; 631.4
• DOI: 10.2136/vzj2015.11.0146
• Languages: English
• ISSNs: 1539-1663

Abstract

Abstract : Many clayey soils shrink as they dry, causing a shift of porosity from inside to outside the soil aggregates and leading to the formation of shrinkage cracks and/or surface subsidence. During swelling, shrinkage cracks begin to seal and/or the soil surface rises. Previous models have focused on describing shrinkage at the aggregate level, with little success in predicting soil cracking and subsidence. To remedy this shortcoming, we provide a unified, physically based set of governing equations for these three pore domains (aggregates, cracks, and subsidence) and predict the porosity distribution among domains as a function of soil water content and minimal (up to six) additional parameters. Examples collected from a variety of soils show how these functions describe shrinkage of soil samples in the laboratory; quantify the relationships among soil suction, soil shrinkage, and water content using the same set of parameters; and predict sealing of soil cracks in the field. This approach provides the framework for accurate and unified hydromechanical modeling of swelling soils.