Field Measurements for the Effectiveness of Compaction of Coarse-grained Soils

摘要

Most earthwork construction specifications recommend a lift thickness of 0.2 m for subgrade soils during road construction. These limits were originally implemented to ensure uniform compaction across the entire depth of the soil lifts. However, it has also been argued that the larger footprints and weight available in modern compaction equipment could potentially compact thicker layers without sacrificing the mechanical performance of subbases. This paper describes a field study on the effects of the lift thickness and compactors on the quality of compacted subbases. The effectiveness of two compactors was evaluated on coarse-grained soils. Different types of geotechnical instruments were used to determine variations in the mechanical properties of soils under applied compaction energy. The main goal was to combine the information of different testing types to determine whether it is possible to use a thicker lift of coarse-grained subgrade soils during compaction. The field test results show that compaction energy propagates up to the 0.3-m depth into the soil lift. Therefore, the conventional 0.2-m lift thickness specification for road construction may be updated to potentially save construction costs without compromising mechanical performance.