Piling on alluvial land requires a special approach. Alluvial soil typically consists of water-saturated sand with a very loose structure, obtained by hydraulic flushing from quarries or dredging. Specifics of Working with Alluvial Soil Alluvial soil differs from conventional backfill in the way it is formed. With hydraulic filling, sand is added with a large amount of water, settles in a designated area, and gradually dehydrates. This type of soil has certain characteristics. Characteristics of alluvial soil: • High initial moisture content (30–40% or more) • Very loose structure—porosity coefficient of 0.7–0.9 • Unevenness across the surface—in some areas, more large particles have settled, while in others, more small ones have settled. • Continued shrinkage under its own weight for 1–3 years. ...