Driven Steel Piles

Driven steel piles are used to make up the abutments and/or piers of short span modular steel bridges. These piles are driven to the required depth in order to support the required loads, and a pile bent is installed along the top of the piles to support the bridge superstructure.

Steel piles are driven to the required depth to support the structure. The portion above ground is braced and topped with a pier cap to create a pile bent that supports the superstructure on.

Driven Steel Piles. Photo Credit: Nucor Skyline Steel

Some states connect the steel piles to the pier cap through welds that connect the tops of the piles to steel plates. Other states have used piles that are hollow with precast pier caps; an anchor system is established between the cap and piles with a closure pour used to finalize the connection.

This system provides a driven pile instead of a cast-in-place concrete pile. Cast-in-place piles require more time and preparation.

Photo Credit: LB Foster

Where is the substructure and/or foundation on a bridge?

Substructure

The substructure consists of the portion of the bridge that supports the entire structure on the given surrounding soil. There are varying designs due to the different soil conditions for each bridge site and the different weights of the structures for each project.

Foundation

The role of the foundation of a bridge structure is to create a smooth transition allowing the internal forces to flow between the bridge and the ground. Foundations are the ‘bridges’ or links between the bridge and the ground.

There are really only two types of bridge foundations – although each has many variations – ‘spread’ foundations and ‘piled’ foundations. Both types must transfer forces into the soil beneath the bridge.

Spread Foundation

Piles Foundation

Photo Credit: Bridges