A drilled-shaft foundation having a total length of 12 m is constructed in an area underlain by clay soil having the following properties: From the ground surface to a depth of 7 m, the soil cohesion...

A drilled-shaft foundation having a total length of 12 m is constructed in an area underlain by clay soil having the following properties: From the ground surface to a depth of 7 m, the soil cohesion is 45 kPa and the unit weight is 16.5 kN/m³; below 7 m, the soil cohesion is 110 kPa and the unit weight is 19 kN/m³. This foundation unit will have a belled (underreamed) bottom; the shaft section has a 1 m diameter, and the base of the bottom section has a 2 m diameter. The bell forms a 60° angle with the horizontal plane. Compute the design downward capacity using the empirical design method, Table 14.