Load Transfer and Factor of Safety of Lali Bridge Caisson Foundation

The load transfer and factor of safety of Lali Bridge caisson foundations is discussed. The bridge is on Karoon River at elevation of 240 m after Gotvand Dam impoundment and the river level is at 110 meter now. This cable stay bridge has two piers each having two caissons foundations. The deck of the caissons is 16 by 32 meter and has a thickness of 5 meters. The caissons are of 10 meter diameter and have a depth of 20 meter in the rock. The submergence of the caissons after bridge operation necessitated a detailed study of load transfer and factor of safety and extreme care during construction to prevent disturbance of the surrounding rock interface.