Fast Determination of Soil Behavior in the Capillary Zone Using Simple Lab Tests

AUTC project number: 410025

PI(s):

Xiong Zhang (UAF)

Funding:
  • US Department of Transportation (RITA)
  • Texas A&M University
  • Start Date: Jul 20, 2010
  • End Date: Aug 15, 2012

Project Summary

Frost heave and thaw weakening are typical problems for engineers building in northern regions. These unsaturated-soil behaviors are caused by water flowing through the capillary zone to a freezing front, where it forms ice lenses. Although suction-controlled tests are the standard for characterizing unsaturated soils, such testing is too laborious, time-consuming, and costly for routine engineering projects. Characterizing the stress/strain behavior for only one unsaturated soil can take up to three years, and moisture content measurements are unreliable. This research team seeks to develop a method for rapidly determining and analyzing unsaturated soil behavior through a new approach, the Modified A shake table model of a single pipe embedded in a frozen silt layer overlying a liquefiable sand layer adjacent to a river channel. In these experiments, the loads induced on the bridge foundations by unfrozen and frozen ground crust will be measured from two shake table tests by means of strain gauges. State Surface Approach. The MSSA can potentially reduce the time required to characterize unsaturated soils to a few weeks, as well as provide more reliable measurements and more representative soil behavior. If successful, this research will produce a useful tool for geotechnical engineers, allowing fast, practical, and more comprehensive soil characterization for more complicated soil behavior problems.