A Numerical Study on The Depth of Active Zone in Shirnk-Swell Soil Problem

Abstract

The damage triggered by shrink-swell soil movements (SSSM) on structures built on top of them continues being a source of problems for the construction industry worldwide that can be measured in millions of dollars annually. In order to maintain the serviceability of the structure, special concerns on the SSSM are required during the design process. This research focuses on the estimation of the depth of active zone (DAZ), as one of the key parameters in when dealing with shrink-swell soils. A fully coupled hydro-mechanical finite element program CODE_BRIGHT is adopted to investigate the extent of the DAZ numerically. The analyses focused on the estimation of the DAZ under different conditions, such as, position of the water table, soil permeability and environmental conditions. Besides, a survey involving geotechnical consultants was conducted to learn about the local knowledge and practice about the determination of the DAZ in different cities in Texas. The DAZ values collected from the survey agree well with the DAZ results obtained from numerical models that replicated the local conditions reported in the survey. The simulation results also show a good correlation between the permeability, ground water table, weather history and the depth of the active zone.