Ancient civilizations understood the concept, but the idea got lost in the dusts of architectural time, until recently that is.
Although the concept of geosynthetic reinforced soil-integrated bridge systems has its roots in antiquity, the idea has re-emerged as a way to build bridges faster, cheaper and safer. One such bridge may be coming to Barton County.
“This would be the first one of these in Kansas,” said Barton County Engineer Clark Rusco.
What is this method? The words are a mouthful, but picture a layer cake, Rusco said.
Rather than drilling a deep foundation and using pilings, the reinforced soil method builds up layers of compressed rock separated by a membrane of high-tech synthetic fabric. Once these are done, the bridge deck is lowered into place.
The idea was first revisited in the 1970s, but serious research didn’t take place until the 1990s. The first GRS bridge in the United States was built in 2005 in Defiance, Ohio, and they are now common in many states.
In fact, a skeptical Rusco and other local officials recently visited Ohio and came back convinced this system will work here.
Rusco has prepared a grant application for a GRS system from the Kansas Department of Transportation’s  off-system bridge replacement funds. The application has been sent to KDOT for its review.
The target of this project is a bridge 2.7 miles east of Great Bend. This grant is an 80-20-percent match, Rusco said.
For this project, the state would pay $396,000 and the county $79,000. However, after the state pays the county back for engineering services, the total local cost would be around $40,000.
The GRS method works on shorter, single-span bridges. The longest GRS bridge in the country is 140 feet.
However, most bridges are 50 feet or less, Rusco said. That is the case in Barton County, as well.

Benefits
A GRS bridge provides a smooth transition from the bridge onto the roadway, and alleviates the “bump at the bridge” problem caused by uneven settlement between the bridge and approaching roadway.
This process reduces construction time from weeks to days, Rusco said. There is no need to wait for cast-in-place concrete to dry since the substructure is immediately ready for the bridge. In addition, on-site changes are easy to accommodate and weather is rarely a problem.
Bridges built with GRS IBS are stronger, more durable, stronger and flexible than bridges built using traditional methods, Rusco said. They can even withstand an earthquake.
They are also less expensive to build, information from the Federal Highway Administration notes. Bridges constructed with the GRS IBS cost 25 to 60 percent less than bridges built with traditional method.
Shortened construction time means fewer labor hours. In Defiance County, one bridge abutment was built in just three days. Using traditional techniques such as cast-in-place construction, that same abutment would have required two to three weeks.
This lower-tech option also reduces material costs and there are fewer parts. Inexpensive, common materials and equipment are used.
Some ancient buildings remain standing because their builders understood an important concept: reinforcing mud building blocks with woven reeds greatly increases a structure’s strength and durability. When the Federal Highway Administration launched its “Bridge of the Future” initiative, its engineers applied modern technologies to this old concept.
According to the FHA, approximately 44 bridges have been built on GRS abutments in the United States, 27 of those using GRS IBS.