CTH M over S. Fork Eau Claire River, Clark County
Transportation | Structure Design
This rural design project completely replaced the existing three-span steel deck girder bridge that carries CTH M over the S Fork Eau Claire River. The new bridge is a 7-span continuous haunched slab structure, and with an overall project length of approximately 1,365 feet, is now the longest bridge in Clark County!
When CTH M would close several times a year due to roadway overtopping during heavy rain events, motorists were required to take a 24-mile detour route. In order to alleviate the overtopping frequency to every 25 years (or a 4% annual recurrence interval), CORRE prepared plans to raise the profile by 5.3 feet and construct a new 7-span continuous haunched slab bridge.
Significant hydraulic modeling during preliminary design determined that the approved project length would need to be significantly longer than the 750 feet approved in the original funding application. CORRE prepared a Bridge Length Justification Report and submitted a Change Management Request, securing more than $1M in additional funding for the increased project length.
At the request of the Bureau of Structures, CORRE also performed a complex structural Finite Element Analysis to confirm the design and load-carrying capacity of the bridge.
The new 7-span structure is skewed 30 degrees and features a 30-ft clear width between Type M open steel railings.
Location
Clark County
Client
Clark County Highway DeparTMENT
Construction Cost
$3 Million
Fast Facts
- Rural bridge replacement
- Longest bridge in Clark County
- New 7-span continuous haunched slab structure
- Profile raised to reduce the frequency of overtopping from heavy rain events
