Development, adaptation, and interpretation of cone penetrometer sensors for geoenvironmental subsurface characterization.

摘要

This thesis focuses on the development and application of improved methods of geoenvironmental site characterization using cone penetrometers. Specifically, the study examines the operation of a newly developed integrated optic sensor for the quantitative detection of benzene, toluene, ethylbenzene, and xylene contamination. Bench-scale evaluation of the sensor, miniaturized for integration into a cone penetrometer, was performed in a silica sand and aqueous matrix.; Additionally, a methodology based on cavity expansion theory, critical state soil mechanics, and an analytical solution to the consolidation equation was developed in order to evaluate the coefficient of consolidation of a soil deposit from piezocone dissipation testing. The method evaluated the coefficient of consolidation from monotonically decreasing dissipation tests in soft clays and the dilatory dissipation behavior observed in stiff clays.; Finally, a method for the in-situ determination of soil permeability was developed based on seismic piezocone dissipation testing and one-dimensional consolidation theory. Using the previously mentioned estimation of the coefficient of consolidation in combination with three alternate methodologies for the evaluation of the constrained modulus, predictions of the soil permeability were performed.