Drilled Shafts

Drilled Shafts are typically installed by drilling a large diameter (3- to 8-ft) casing to design depth. The casing is cleaned of soil cutting prior to a steel reinforcing cage placed to the bottom of the borehole. A high slump concrete is tremied from the bottom of the borehole to the top of the casing. The casing is withdrawn to design elevation exposing the competent soils to form a bond between the soil and the grout. Where the overburden soils are not loose or the groundwater level is not sufficiently high, drilling mud can be used in lieu of casing.