Steel Expedites Replacement of Washed Out Bridge in South Dakota
Mother Nature was relentless on South Dakota in 2019, bringing rain at unprecedented levels throughout the year. That rain led to the washing out of an old multiplate structure on the Baptist Creek in Clay County South Dakota.
TrueNorth Steel was asked to help expedite the production of twin 120″ x 86′ long 5 x 1 galvanized culverts with two 30 degree skewed headwalls. The system was made up of two, 43′ long pieces.
The county chose corrugated steel pipe (CSP) over other alternate products due to its ease of installation, fewer joints and the manufacturing period of the culvert was significantly shorter than concrete pipe or a precast concrete box culvert.
Delivery and installation came off without a hitch and both the contractor and county were extremely pleased with the timeliness of the project from start to finish.
To find designs similar to the multiplate structure in Clay County, the SSSBA develop a a free web-based tool that provides preliminary simple-span and modular designs for steel bridges up to 140 feet, allowing bridge owners and designers to compare steel and concrete structures and make informed choices.
The tool, eSPAN140, provides customized standard designs in less than 5-minutes.
“I have confidence in these bridge designs and details, as they were developed by university researchers who are national experts,” says Brian P. Keierleber, PE, county engineer for Buchanan County, Iowa. “eSPAN140 gives me a design I can take to a fabricator, which saves time for me and precious funds for our county.”
What are buried steel bridges?
Buried steel bridges provide an economical choices for bridge replacement or bridge rehabilitation.
They essentially are a corrugated steel pipe or structural plate pipe systems that is “buried” with backfill to carry loads through soil-structure interaction. This means the bridge structure itself and the backfill soils surrounding the structure interact with each other to support the loads. In effect, the backfill material is part of the bridge.
Because of this interaction, the bridge structure is typically lighter, and there can be significant savings in structure costs.
There are also many cases where buried bridges can carry heavier loads than traditional bridges because of the benefits of spreading vehicle loads through the fill. Buried bridges do not require abutments; and unless foundation soil conditions are poor, do not typically
require deep foundations.
An additional benefit with buried bridges is that they can be tailored to site conditions and geometric requirements. The design includes inputs for site soils and backfill, meaning that locally available materials can often be used in construction and the structure can be tailored to fit the needs of the site and the owner’s requirements.
The 9’-0” x 3’-10½” single- radius steel structural plate arch was assembled by the contractor and installed in only two days.
A 75 ft span x 15 ft rise buried steel bridge was constructed over a creek crossing in Alaska.