Sand drainage is a radial consolidation process that increases the rate of drainage in the drainage rate on the embankment by driving a casing into the embankment and making vertical orifices. These holes are filled again with the proper grade of sand. To speed up the consolidation settlement process for the construction of some structure, the useful technique of building sand drains can be used. Sand drains are built by pushing down gutters or hollow mandrels on the floor. The holes are then filled with sand, after which the guts are parallel outwards. When an overhead is applied to the soil surface, the water pressure in the pores will increase and drainage will occur in the vertical and horizontal directions (Figure 5.48). Horizontal drainage is induced by sand drainage.