In Orange California, the alluvial soils from the Santa Ana River create a varied subgrade that demands careful attention. We often see projects where the top few feet are silty sands with occasional clay lenses, which behave differently under moisture changes. Before committing to a pavement section, we run a series of lab and field tests to establish the actual support conditions. A common first step is a CBR test to gauge bearing capacity, and if the soil is expansive, we also check Atterberg limits to avoid long-term pavement heave. The key is to match the design to the specific soil found on each lot, not just to assume a standard value from a nearby street.
A wet winter can turn a marginal subgrade into a soft base, so we always test after the rainy season in Orange.
