Geosynthetic reinforced soil-integrated bridge system technology – part of all three rounds of Every Day Counts – is developing a track record.

“Before GRS-IBS was named an EDC technology in 2010, we had a few projects in a few counties,” said Daniel Alzamora, Federal Highway Administration geotechnical engineer and leader of the EDC-3 GRS-IBS Innovation Deployment Team.

Now the number of GRS-IBS structures nationwide is approaching 300 and Idaho is among those who are using this technology.

GRS-IBS uses alternating layers of compacted granular fill material and layers of geosynthetic reinforcement to support bridges. The technology integrates the roadway approach to the bridge, eliminating the bump drivers commonly feel between the road and bridge.

Turner Road Penstock Bridge

This project is administered by the Local Highway Technical Assistance Council and is being built using GRS-IBS technology.

See a time-lapse progression of this GRS-IBS bridge – HERE.

The project is located on Turner Road, a farm to market road approximately 0.2 miles west of Grace, Idaho. The Turner Road Penstock Bridge carries Turner Road over an eleven foot diameter wooden penstock enclosed pipe that feeds a PacifiCorp owned power generation plant. The penstock is four and one half miles long beginning at the Grace Dam Complex on the Bear River and ending at the Grace Power Plant.

The Turner Road Penstock Bridge was closed to all traffic due to structural deficiencies. The bridge consisted of two arch pipes founded on concrete and pile foundations with concrete wing walls containing the roadway fill over the arch pipes. The concrete wing walls were pushed out of alignment and severely deteriorated with large open working cracks. If a large portion of the wings had broken off and landed on the wooden penstock, it was expected the penstock would crush. The result of this damage would have been very costly and may have resulted in the total loss of the entire penstock.

Status: The project is currently in construction and about 90% complete. The anticipated completion date is spring 2016.

Project Manager: Matt Koster – mkoster@lhtac.org

Sponsor: Caribou County Road and Bridge Department