How can moisture influence the compaction of sandy soils?

Moisture plays a crucial role in the compaction of sandy soils. Insufficient moisture can lead to poor compaction because sandy soils have large, individual particles that need a certain level of cohesion to effectively bond during compaction. When the moisture content is too low, the particles do not stick together as well, resulting in voids and lower density, which ultimately diminish the soil's stability and load-bearing capacity.

Conversely, excessive moisture can lead to instability in sandy soils. While some moisture is necessary to facilitate the compaction process, too much water can create a condition known as "liquefaction," where the soil loses its strength and behaves more like a liquid than a solid. This can lead to the particles being displaced, thus undermining the intended density and structural integrity of the compacted layer.

This balance of moisture is particularly important in sandy soils, making the first choice the most accurate one in understanding how moisture influences compaction.