The Constant Head Test is primarily used for which type of soil?

The Constant Head Test is primarily used for coarse-grained soils, such as gravels and sands, because these types of soils exhibit higher permeability, allowing water to flow through them faster than fine-grained soils. In this test, water flows at a constant rate through a soil sample, and the hydraulic conductivity can be calculated based on the flow rate and the gradient of the head (water level).

Coarse-grained soils are typically characterized by larger particle sizes, which create larger void spaces, leading to quicker drainage and flow of water. This method is effective for measuring the permeability of soils that do not retain water and allow for continuous flow under a constant head of water. The test provides a straightforward means of assessing the drainage characteristics and hydraulic conductivity, crucial for various engineering applications, including foundation design and slope stability.