What is the function of caissons in bridge construction?

Answer: B — To carry substructure loads to sound soil or rock

The primary function of caissons in bridge construction is to carry substructure loads to sound soil or rock. Caissons are large, watertight structures that are sunk into the ground to create a stable foundation for the bridge's support. They are particularly useful in situations where the surface soil is not strong enough to support the weight of the bridge, requiring the loads to be transferred deeper into more stable geological formations. By using caissons, engineers ensure that the bridge has a solid and reliable base, which is essential for the overall structural integrity and longevity of the bridge. This capability makes them crucial in bridge design, especially in areas with challenging soil conditions or where the bridge spans a body of water.