steel buried bridge Captain William Henry Moore Bridge

Project Spotlight: Captain William Henry Moore Bridge

Topics: Buried Bridge

Article provided by the National Corrugated Steel Pipe Association

The Captain William Henry Moore Bridge is an historic suspension bridge on the Klondike Highway, crossing Captain William Moore Creek about 10 miles north of Skagway, Alaska. The existing 110 ft span suspension bridge was constructed in 1976 and connects Skagway to the Yukon highway network.

Throughout its history the bridge has carried a lot of traffic, including many heavy trucks loaded with ore. The heavier ore trucks have been causing significant deflection, reportedly causing distress in some of the foundation ties. The Alaska Department of Transportation and Public Facilities (ADOT&PF) engaged DOWL Engineers of Juneau, AK to evaluate potential replacement structures.

Buried Bridge Corrugated Steel Pipe

A large span deep corrugated structural plate was used to provide a hydraulic opening for the fast moving Captain William Moore Creek.

After evaluating several potential options, DOWL and ADOT&PF elected to use a large span deep corrugated structural plate Buried Bridge to provide a hydraulic opening for the fast moving Captain William Moore Creek while filling in the rest of the gorge with roller compacted concrete. The 75 ft span x 15 ft rise Buried Bridge bears on foundations over 100 ft below the Klondike Highway and was design to act as a stay in place form for placement of the concrete in the gorge.

The structure had to be built on a 16 degree skew to the highway because of the rough terrain and site limitations.

Hamilton Construction, LLC also requested that the structure be fabricated so that it could be built in place completely from the outside because of insufficient space to operate equipment on the inside of the structure during construction. Contech/Big R Bridge worked with Hamilton to design an external bracing system to allow for the support of the skewed ends of the structure without a concrete collar.

The structure was also manufactured with special splicing hardware to allow it to be pre-assembled in a staging area in three large sections, lowered into its place on the footing, and each of the large sections connected completely from the outside. This helped to speed up assembly in an area where the construction weather window is short as well as improve the quality and safety of the installation since much of the assembly could be completed in a more controlled setting. After the sections were connected, the external bracing to support the skewed ends was attached.

The backfill material consisted of concrete placed in lifts up to a height of about 5 ft above the crown of the structure. Roller compacted concrete (RCC) was placed above that level up to the road subgrade 75+ ft above. One key component to the success of the project was that DOWL and ADOT&PF involved manufacturers in evaluating the feasibility of the project early on and allowed for flexibility in means and methods for construction as the installation details were being developed. The original bridge remains in place for recreation uses.

Learn More

For More Information:

Michael McGough
14070 Proton Road, Suite 100 LB9
Dallas, TX 75244
 972.850.1907
Joel Hahm
CONTECH Engineered Solutions LLC
9025 Centre Pointe Drive
West Chester, Ohio 45069
970.347.2208

Click on thumbnails below to view the full image.

Captain William Henry Moore Bridge

Captain William Henry Moore Bridge

Captain William Henry Moore Bridge

Captain William Henry Moore Bridge

Captain William Henry Moore Bridge

Captain William Henry Moore Bridge

Captain William Henry Moore Bridge

 

 

 

 

 

 

 

 

 

 

 

Related Resources: Buried Bridges

Iowa County Saves Costs by Choosing Buried Steel Bridge for Replacement Project

Buried steel bridge is constructed with local crews in Buchanan County Iowa.

Contech - Buried Bridge - California

What You Should Know About Buried Bridges

Joel Hahm, Contech Engineered Solutions, provides an expert Q&A on buried bridges.

Steel Buried Bridge

Hidden in Plain Sight–the Design, Cost and Maintenance Advantages of Steel Buried Bridges

Steel buried bridges are durable and resilient, with the ability to support very heavy loads.