Sheepsfoot roller Compaction Equipment

This photo was taken during a visit in a construction site of PATHE highway in Greece (Patras-Athens-Thesallonica-Euzonoi National Road). It is used to compact soil layers and is typically called sheepsfoot roller. There are many techniques and equipment used for the compaction of soils and the sheepsfoot roller is one of those. It is particularly applicable for fine-grained soils or "dirty" coarse-grained soils with more than 20 percent passing No.200 sieve. It is also particularly appropriate for compaction of the impervious zone of an earth dam. It is not however suitable for clean coarse-grained soils. Compaction is the procedure for increasing the specific weight of the soil which is achieved by decreasing the volume of the air which exists in the soil's pores (between the grains). Based on the results drawn by the Proctor test, it is determined the optimum water content and the dry maximum unit weight. Then it is calculated how many times the equipment (of a known weight) must roll on the soil layer to achieve the specifications of the soil layer.

References

• G.A. Athanasopoulos, Theory and problems in Soil Mechanics, University of Patras editions.
• Foundations and Earth Structures, Naval Facilities Engineering Command