The Behaviour of Low Confinement Spun Pile to Pile Cap Connection

An experimental and numerical study of the low confinement spun pile to pile cap connection typically used in Indonesia was performed. A cyclic loading test on two spun pile connections was performed. One was an empty spun pile (SPPC01) and another was filled with reinforced concrete (SPPC02). No shear failure was observed during the test. Filling the reinforced concrete into the spun pile increase the capacity by 54% and also improve the ductility from 4.26 to 4.70. A numerical study was performed to simulate the effect of the soil. A similar spun pile with a fixed connection to the pile cap was embedded in clay. Soil affects the strength and ductility of the connection, but it is not significant. Stiffer soil results in higher bending capacity. The capacity could be approximated based on the P-M interaction. To conclude, the connection of the spun pile to pile cap perform well though the spun pile has insufficient confinement.