Upper-bound and load–displacement solutions for laterally loaded piles in clays based on energy minimisation

An important part of any foundation design procedure is the evaluation of the ultimate capacity and displacements under working loads. The most widely used solution for ultimate loads of laterally loaded piles in clays is that of Broms (1964). Broms ignored the soil resistance down to a depth of one and a half diameters, and used a constant resistance value of 9s_ud along the remainder of the pile, where s_u is the undrained shear strength, and d is the pile diameter.

While the value of 9s_ud closely corresponds to the best-known lower-...