A Moisture‐Insensitive Mechanical Index for Intelligent Soil Compaction: Theory, Development, and Field Validation

ABSTRACT In this study, a new intelligent compaction (IC) mechanical index, intelligent compaction vibration modulus E ICV, was established by considering the influence of the subgrade moisture content. The field test was designed with varying moisture content sections to investigate the influence of moisture content on the E ICV and compaction meter value ( CMV ). The results suggest that the E ICV had better performance in evaluating the compaction quality of the subgrade than the CMV . It may be due to the similar trend of E ICV and in‐situ test results with the change of moisture content, while the CMV was adverse. Then, E ICV and CMV were performed to regression analyses with the in‐situ test results collected in the respective moisture content sections. The correlation of the in‐situ test results with both E ICV and CMV was strengthened compared with ignoring the influence of moisture content. It suggested that the different IC control standards for different moisture content ranges should be applied, rather than using a single standard in IC technology. Based on it, an IC project verification was conducted to validate the robustness of E ICV by comparing it with other intelligent compaction measurement values (ICMVs). The results demonstrate that E ICV has a stronger ability to reflect the compaction quality of subgrade compared with other ICMVs due to a better mechanical basis and considering the influence of moisture content difference. This study is conducive to improving the accuracy of IC evaluation and promoting the application of IC technology in subgrade construction.