INVESTIGATING THE EFFECT OF COMPACTION DEGREE AND THE PARTICLE SIZE DISTRIBUTION OF THE FILLING MATERIAL ON THE PULL-OUT CAPACITY OF GRANULAR PILE ANCHOR FOUNDATION

A Granular Pile Anchored Foundation (GPAF) is a technique that was used as a ground improvement technique for the soils that experience significant volumetric strain. The efficiency of GPAF is affected by the type of filling material that is responsible to develop the frictional resistance along the surrounding soil interface. Two types of filling materials were employed in this study; sand and crushed stone. GPAF was investigated by using sand material at different compaction degrees, and by using crushed stone at different particle size distributions. The results showed the variations in pull-out capacity which increased as the compaction degree increase. Similarly, the GPAF with filling material of coarse particles of crushed stone showed higher pull-out capacity compared to that for filling material with fine particles of crushed stone. This behaviour was attributed to the frictional resistance that was increased due to the increase of friction degree caused by high compaction degree for sand, and coarse materials for crushed stone samples. Therefore, this study is emphasizing the importance of selecting appropriate filling material used in GPAF in increasing the pull-out capacity of GPAF.