Field Calibration and Spatial Analysis of Compaction-Monitoring Technology Measurements

To implement compaction-monitoring technologies (i.e., continuous compaction control and intelligent compaction), robust and versatile specifications are needed. These specifications require field calibration of the various machine sensor outputs to in situ soil compaction measurements. The goal of this study was to provide insights into (a) the nature of compaction-monitoring measurements, (b) how the measurements are related to soil properties determined from in situ compaction control tests, and (c) how compaction-monitoring technology may be addressed in specifications for using the technology in practice. To accomplish this goal, testing was conducted on one-dimensional test strips with several nominal moisture contents for developing statistical regression models that relate machine drive power and compaction meter value data to engineering and index properties of soil. In addition, a two-dimensional test area with variable lift thickness and moisture content was constructed and tested by using both compaction-monitoring technology and in situ devices (e.g., nuclear moisture-density gauge, portable falling weight deflectometer). The spatial distribution of the data was investigated. The significance of this research is that it represents the first documented field calibration of both one-dimensional and two-dimensional tests areas on similar soils and introduces a new approach to generating pass-fail criteria based on compaction-monitoring technology.