The available ductility of prestressed concrete piles when subjected to large inelastic deformations due to severe earthquake loading is considered. The results of tests and analyses of five pretensioned prestressed concrete piles with a 400 mm (15.7 in.) octagonal cross section are reported. The results showed that when a satisfactory quantity of spiral reinforcement is present, the piles were capable of undergoing large post-elastic deformations when subjected to cyclic lateral loading without significant loss in load carrying ability.
