State Transportation Innovation Council (STIC)

What are the Benefits?

Geosynthetic Reinforced SoilIntegrated Bridge System (GRS-IBS)

Geosnythetic Reinforced Soil or GRS is a very old conceptthat is being modernized with today’s technology. Today,GRS uses alternating layers of geotextile and compactedstone to create bridge substructure units. Those units canbe combined with beams and a deck to create anIntegrated Bridge System (IBS).The concept of reinforced soil has been used throughouthistory, including sections of the Great Wall of China thatare still visible today, which affirms the durability of theGRS concept in the right application.GRS-IBS is a form of accelerated bridge construction thatlowers costs and reduces construction time, minimizing theimpact to the traveling public.Using the reinforced soil method for the foundation of thebridge allows the bridge to be built much faster and in anenvironmentally friendly manner. The GRS-IBS bridge canbe built by local labor or maintenance friendly forces withreadily available materials. This design concept uses lessheavy equipment and does not require intricateconstruction concepts.Overall, GRS-IBS can reduce costs by 25-60 percentcompared to conventional construction methods. GRS-IBSuses common equipment and materials and requires fewerparts which lend itself to easier maintenance. In addition,GRS-IBS also utilizes a flexible design that can be easilymodified to adjust to unforeseen circumstances or weatherevents.GRS-IBS is a great solution to address either structurallydeficient bridges on low volume roadways or over lowvelocity streams. In addition, studies have found GRS-IBSable to withstand scour testing up to 15 feet per second.PennDOT encourages the use of GRS-IBS technologythrough its inclusion in Publication 447, New Products forLow Volume Roads. This publication provides approval tolocal governments to utilize innovative products for theirlocal roadways.

PUB 752 GRS (8-13)

Reduced construction time andcosts, with costs reduced 25 to 60percent from conventionalconstruction methods

Easy to build with commonequipment and materials; easy tomaintain because of fewer parts

Flexible design that is easilymodified in the field forunforeseen site conditions

State Transportation Innovation CouncilPennsylvania Department of Transportation | Federal Highway Administration

For more information, visit www.ModernDOT.pa.gov.

U.S. Department of TransportationFederal Highway Administration

The Pennsylvania STIC is a cross-section of stakeholders, state and federal agencies, local governments, research organizationsand industry partners that work together to forge an environment of innovation, imagination and ingenuity to pursue specific

initiatives and their rapid implementation to deliver a modern and high-quality transportation system.

Interested in learning more?For more information, please contact Michael Bonini at 717-772-4664 or via email atRA-pdPennDOTSTIC@pa.gov.

Facts on GRS-IBS:• Reduces construction costs by 25 to 60 percent compared to conventional

construction methods

• When integrated into the construction of a bridge, the use of GRS makes bridgeabutments that are easier and faster to build

• GRS-IBS uses common, readily available materials and equipment

• Easier to maintain as they contain fewer parts

• Documented to shorten project delivery (in FHWA research studies)

• Scour tested up to 15 feet per second

GRS-IBS Adoption in Pennsylvania:• More than 10 PennDOT bridges are programmed to be completed in the 2013 and

2014 construction seasons

• Two GRS-IBS bridges have been constructed in Clearfield County (Huston Townshipand Sandy Township)

• Local governments are also installing GRS-IBS bridges all throughout Pennsylvania

• Included in PennDOT Publication 447, New Products for Low Volume Roads