What is the typical compaction outcome for lifts of clay soils?

The typical compaction outcome for lifts of clay soils involves achieving a compacted depth of about 6 inches. Clay soils tend to undergo significant changes in density when compacted, primarily due to their fine particle size and the moisture content they retain.

When using conventional compaction methods, each lift of clay is usually compacted to a thickness that allows for adequate densification without overloading the underlying layers. The 6-inch lift is a standard practice that ensures efficient compaction while avoiding excessive pore pressure and potential failure of the soil structure. Adequate moisture content during compaction also plays a crucial role in successfully achieving the desired density in clay soils.

Other thicknesses like 8 inches are more typical for granular soils, where larger particle sizes require deeper lifts for effective compaction. Additionally, saying that clay does not compact overlooks the nature of these soils; they do compact, but the process and effectiveness are highly dependent on moisture content, lift thickness, and compaction technique used. The distinction of the correct answer lies in understanding the appropriate practices for compaction in clay specifically.