Soheil Nazarian

Comparison of Laboratory and Field Moduli of Compacted Geo-Materials

The moduli of compacted geo-materials are estimated in the laboratory or in the field. Laboratory tests are essential to obtain the parameters that affect the behavior of the materials. Field tests, especially nondestructive field tests, are more practical and desirable because they are rapid to perform, and because they test a volume of material in its natural state. Empirical relations between the resilient modulus and the modulus from in-situ test are sometimes used in the preliminary stages of design and planning. Unlike in situ methods, these relations do not take into account the site-dependent variation in material properties. This paper represents an alternative process based on seismic nondestructive testing technology for relating the results from laboratory and field moduli from a number of chemically or mechanically stabilized geo-materials. Attention is also paid to understanding of the results from seismic tests and incorporating them in the existing design methods, specifications and common practices.

Evaluation of Pavement Layers and Foundation Sites with Seismic Surface Wave Method

This paper provides the fundamentals, capabilities and limitations of the seismic surface-wave method as applied to in-situ testing of pavement and foundation and represents the results obtained from its recent applications in a number of projects. These applications include characterization of flexible pavement layers during construction, monitoring of early-age strength development of Portland cement concrete and evaluation of soil foundations. The issues on understanding the results from surface-wave tests and how to incorporate them in those requirements adopted in most existing specifications or common practices are discussed.