A Study on the Design Parameters of Subgrade Soil by Different Compaction Methods

It has been widely used the proctor compaction and laboratory tests for evaluation of its design properties and compaction characteristics for subgrade soils. However, the compaction roller with static load has been used for compaction of subgrade soils. The purpose of this research was to evaluate the design properties of subgrade soil, which was compacted by Servopac gyratory compactor to simulate the field compaction. Field compaction data and couple of properties were collected from road construction site. Disturbed soils was used for laboratory compaction and gyratory compaction. For the comparison, block sampling was conducted on the subgrade after finishing the final compaction. Uniaxial compression strengths for field specimen from block sampling and specimen by Servopac gyratory compactor are almost same. But, those of specimen by D-method and A-method using proctor showed a little big difference for those of field specimen. This means that evaluation for design properties for subgrade soil by proctor compaction is not proper and gives the higher values than that of field compaction-soil. Judging from the un confined creep test, the trend of settlement is very closed between field compaction soil and gyratory compaction soil.