An Automatic Portable Near Surface Soil Characterization System

Soil strength, type, and moisture content are needed for site characterization applications and to assess the load carrying capacity of soil in construction control applications. Currently, no portable, automatic, easy-to-use field methods exist to measure the required soil parameters. In this paper, we describe a new instrument that integrates and extends two proven technologies, the cone penetrometer (CPT) and dynamic cone penetrometer (DCP). A portable Rapid Soil Characterization System is under development to perform near surface assessments to determine trafficability for heavy vehicles and aircraft. In the construction control context, the new device has the potential to eliminate errors in the measurement of soil strength due to soil type and moisture effects. A fully automatic prototype system has undergone limited field demonstration at the USACE facility in Vicksburg, MS. Preliminary laboratory and field test results indicate that the required soil geotechnical parameters can be extracted from dynamic penetration data, providing a near surface instrument that can provide accurate soil strength assessment to a depth of one meter.