ABSTRACT
Which Method to Use There are wide variations in the values of Qb' Qp Qu and Qa between the different methods. The relative proportions of loads carried by skin friction and base resistance also vary between the methods. The order of preference of the methods may be listed as follows;
Example 15.11 A concrete pile 18 in. in diameter and 50 ft long is driven into a homogeneous mass of clay soil of medium consistency. The water table is at the ground surface. The unit cohesion of the soil under undrained condition is 1050 Ib/ft2 and the adhesion factor a = 0.75. Compute Q
u and Q
a with
F s = 2.5.
