Shallow water bridges are often supported by a pile foundation. This foundation is created by hammering large poles, generally made of concrete or steel, into the submerged soil with pile drivers. Getting the large pile drivers over the target often requires floating platforms above the surface. Once the piles hit a hard layer of soil, they turn inward or outward at an angle, allowing them to support the lateral load. The final step of this process is to install pile caps to distribute the bridge’s weight and load under the surface.
Cofferdams can be used in shallow water to make foundation building easier. First developed by the Romans, cofferdams are watertight enclosures with water pumped out of them, giving workers solid ground. Today, most cofferdams are made of sheet piles and steel plates. Getting the components into the ground requires a large hammering device. Once the structure is complete, the cofferdams are usually removed.
