SALT LAKE CITY — The Utah Department of Transportation is pioneering another bridge-building technique to save taxpayers time and money.
They are using one of the oldest construction materials known to man to build the bridge — soil, and lots of it.
UDOT is the first in the country to use a reinforced soil technique at the abutment of the bridge. As I-84 traffic speeds over a bridge near Echo Junction, construction crews lay the foundation for the replacement bridge below.
"Basically what we are doing here, is just building a bridge abutment out of soil and reinforcement, instead of concrete," said Tim Rose, UDOT Region 2 deputy director.
Typically, massive steel pylons driven into the ground surrounded by concrete form the bridge abutment. Crews are building the footing for a 58-feet-wide span of multiple layers of compressed dirt separated by a tarp-like fabric. It's called a geosynthetic reinforced soil integrated bridge system.
"Right here is your geosynthetic fabric, then right here is your Geoblock wall facing," Rose said.
Each of the layers is constructed essentially the same way. The dirt is piled in on top of the material and then it's compacted. After that, crews put a geosynthetic material layer on top and start over again.
"Layer upon layer upon layer, all held together by the geosynthetic and the gravity," Rose said.
"We're in here, and out of here. (It's) better for the traveling public because the construction timeframe is shortened."
UDOT said the technique saves a couple hundred thousand dollars on the $3.2 million price tag because concrete is more expensive and time consuming.
"The real advantage here is ease of construction and quickness of construction," Rose said.
Builders will slide the bridge deck into place when the abutment is finished sometime in late summer.
"We're in here, and out of here," Rose said. "(It's) better for the traveling public because the construction timeframe is shortened."