Geosynthetic Reinforced Soil-Integrated Bridge System

Geosynthetically Confined Soil Wall Abutment

Geosynthetically confined soil wall abutments are systems that connect the wall and the soil to create a composite structure. To keep the structure internally stable, fabric sheets are used to connect the wall with the soil behind it in the form of a friction connection. Similar to mechanically stabilized earth systems, these walls are assembled with fabrics placed within the soil while the backfill material is placed in layers.

Geosynthetically confined soil bridge abutments attach to the adjacent soil to support the soil and the bridge superstructure.

Geosynthetic Reinforced Soil–Integrated Bridge System. Photo Credit: ASCE

The blocks of the geosynthetically confined soil abutments were stacked in rows while the fabric is applied between the blocks and the soil. This binding to the soil helps connect and stabilize the wall as a whole.

This system is more stable and has a higher safety factor than mechanically stabilized earth systems. The fabric inclusions are lightweight and the installation process is not difficult.

Deseret News, “UDOT using faster, cheaper technique in bridge building on I-84,” by Jed Boal, July 2, 2013. UDOT is the first in the U.S. to use the reinforced soil technique at the abutment of an interstate bridge. Read more here.

Photo Credit: Wisconsin DOT

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