Preliminary Laboratory Calibration of Cone Penetration in Unsaturated Silt

摘要

Cone penetration testing is an excellent way to determine soil stratigraphy and estimate soil properties. Quite often penetration occurs through a zone of unsaturated soil prior to encountering saturated soils below the water table. However, methods for interpreting cone penetration test results are largely based on assumptions appropriate for saturated or dry soils. At the University of Oklahoma, cone penetration testing is being conducted in a calibration chamber containing unsaturated silt beds prepared to achieve different target matric suction. The goal is to determine the influence of matric suction on the results of cone penetration tests and ultimately to develop methods of interpretation that encompass unsaturated soil mechanics. In addition to the calibration chamber testing, suction controlled laboratory testing of unsaturated soil and numerical modeling is being conducted to extend the usefulness of experimental observations from chamber testing. This paper presents results of cone penetration tests in unsaturated soil from the calibration chamber and discusses preliminary work with regard to improved methods of interpretation.