Unsaturated Soil Mechanics in Engineering Practice

Arizona State University, Scottsdale AZ

Investigators

Abstract

It is recognized that our infrastructure to a very large extent is founded on unsaturated soils. In fact, construction in unsaturated soils is typically preferred when practical, due to reduced costs and effort. However, the geotechnical research community has not yet solved all of the issues of implementation of unsaturated soil theory. One of the primary difficulties in bringing the relatively new fundamental theories of unsaturated soil mechanics into engineering design, analysis, and construction is the difficulty, time, and cost associated with unsaturated soil characterization. Two major elements are needed to bring unsaturated soil mechanics and fundamental analyses into practice: (1) estimates or measurements of soil suction, and (2) moduli or coefficients relating soil suction to performance parameters such as soil shear strength and compressibility. In this research, a range in sophistication of approach will be employed for unsaturated soil characterization. Hierarchical Level 1 will be developed for extremely high-level, large budget projects for which significant expenditures are likely. Hierarchical Level 4 will be developed for lower budget, routine projects for which very limited testing and analysis are common. This research is an important step in bringing unsaturated soil mechanics into present day geotechnical engineering and construction practice. The implementation of unsaturated soils theory would result in more fundamentally sound analyses and design and would lead to substantial savings in construction costs for many applications.