, Professor, Civil, Environmental and Geo-Engineering
Andrew Drescher, Former Professor, Civil, Environmental and Geo-Engineering
Joseph Labuz, Professor & Department Head, Civil, Environmental and Geo-Engineering
Mechanistic-empirical design, quality assurance, and quality control testing require the stiffness and strength -properties of base and subgrade soils to be measured reliably. It is well known that both stiffness and strength are -greatly affected by the soil moisture. There is currently no reliable method to measure the in-situ stiffness and -strength during construction and then relate these to their laboratory-measured counterparts and seasonal values used in-the design process. To bridge such a gap, the proposed experimental program is focused on understanding and quantifying -the relationship between the field and laboratory estimates of the soil stiffness and strength under varying moisture -conditions. This is the second and major phase of an ongoing project aimed at quantifying the effects of moisture on -portable vibratory deflectometer (PVD) and dynamic cone penetrometer (DCP) measurements. The key benefits of this -investigation (Phase II) will be: (i) the development of a novel high-frequency field testing device, termed Portable -Vibratory Deflectometer, for accurate measurement of the in-situ stiffness (namely seismic shear modulus) of granular -base and subgrade soils; (ii) the development of a comprehensive laboratory setup and procedure for simultaneous testing-of the resilient modulus and seismic shear modulus of partially saturated soil specimens; (iii) the performance of -reduced-scale DCP and PVD tests on representative soil volumes aimed at correlating the field- and laboratory-measured -stiffness and strength values; (iv) systematic application of the above developments to a testing matrix spanning four -soils, two density conditions, and three moisture levels.