One of the most important factors in any construction design is the correct estimation of the water content of in situ soil. Soil’s moisture at the time of construction plays a large role in its mechanical response to loading and construction activities. Excessive water content within a site’s soil leads to low strength and constructability problems. By analyzing and testing soil moisture on-site, engineers and contractors are able to limit future structural complications.

Although a site’s soil water content is tested in a laboratory setting during site investigation, oftentimes initial estimates are no longer applicable by the construction phase. Engineers must use on-site tests to ensure that the moisture content of the soil is near its optimal value when compacted.