Initial Characterization of Subgrade Soils and Granular Base Materials at theMinnesota Road Research Project

摘要

This research was conducted on the behavior of materials at the Minnesota RoadResearch Project (Mn/ROAD), the construction of which was completed in 1994. Falling-Weight Deflectometer (FWD) tests were conducted on the test sections at all stages of pavement construction (pre-base, post-base, and post pavement). Deflection values were highly variable due to variability in surface condition, soil moisture content, density, and stress-dependent effects. In general, backcalculated subgrade moduli tended to increase with increasing FWD sensor offset (decreasing stress). Post-base and post-pavement testing also indicated an apparent increase in subgrade modulus relative to pre-base values. Moduli values were also determined for granular base results. The results of this testing will provide a baseline for future analysis of the test sections at Mn/ROAD.