Compaction of Subgrade by High-Energy Impact Rollers on an Airport Runway

High-energy impact rollers (IR) have been increasingly used for earthworks by compacting on-site soils. The IR applies high energy to the ground and densifies deeper soils than conventional rollers and plate-type compactors. A trial program was implemented on the third runway of the Shanghai Pudong International Airport in China to validate the performance of the IR technology. Field monitoring and in-situ testing were undertaken during or after the IR compaction. The cone penetration data indicated that significant improvement in soil properties was measured up to a depth of 4 m after 20 to 25 passes of compaction. However, the improvement of the properties of the very soft silty clay at the depth of 1–2 m was limited. The vibration monitoring data suggested that the IR compaction with 12-t impact module would not cause damage to buildings at a distance of 9.5 m away from the boundary of the compaction path.