PROJECT

Route 86 Bridge Over Table Rock Lake

We designed a 1,815-foot-long bridge on Route 86 over Table Rock Lake in Southwestern Missouri. The structure has two prestressed concrete girders and a three-span plate girder with a maximum span of 350 feet. Our team prepared the conceptual study, National Environmental Policy Act (NEPA) environmental documentation, and preliminary and final plans for the project.

The structure incorporates two lanes with shoulders and a 10-foot shared-use path to enhance safety and accessibility for road users. The substructure consists of deep-water drilled shafts that are 11.5 feet in diameter and reach 130 feet above the stream bed, enhancing resiliency.

The bridge replaces a structure built in 1956, before Table Rock Lake was created by the U.S. Army Corps of Engineers. Structural deficiencies in the truss bridge structure over the Long Arm Creek section of the lake prompted safety concerns and the eventual plan for replacement.

Minimizing impacts to the public while accelerating the project schedule was a key priority for MoDOT. Our staff identified an alignment that not only reduced impacts to surrounding property owners but also allowed construction to occur on an offset alignment to maintain traffic on the existing bridge while the new structure was constructed. 

Client

Missouri Department of Transportation (MoDOT)

Location

Ridgedale, Missouri

Region

Midwest

Services

Bridges

Environmental Studies & Permitting

National Environmental Policy Act (NEPA)

Industry

Transportation

"The work Burns & McDonnell performed on the preliminary and NEPA phase at the Route 86 Table Rock Lake Bridge was outstanding. ... It was an easy decision to continue this major bridge project into final design.”

Kristi Bachman, PE

Route 86 Project Manager, MoDOT Southwest District

The project team determined cost-effective solutions to design challenges, including frequent lake level changes and the presence of superelevation. The proposed bridge included a 7-foot change in profile grade from the existing truss. To accommodate the new grade and lake level elevation, our team designed large-diameter drilled shafts 115 feet deep.

Our design also incorporated a superelevation transition in both the east and west approach units. The horizontal and vertical curvature, in conjunction with the superelevation in Unit 1, required stepped and sloped top flanges in the Type 6 prestressed concrete girders. Bearings were offset on the expansion bents so that a large dead load movement would not be induced into the drilled shafts from the corresponding vertical load from each of the adjacent units. Steel plate girders in Unit 2 incorporated 10.5-foot deep webs, and the steel sections over the interior bents were hybrid sections using Grade 50W steel for the web and Grade HPS 70W for the flanges.

We also supported MoDOT in evaluating project delivery options. The selected design-bid-build option includes alternative technical concepts (ATCs) in project development and bidding processes, which allows contractors to present alternative construction options for the intermediate bents located within the lake at nearly 140 feet in depth. We are supporting the ATC evaluation process and preparation of alternate plan sets needed to bid approved ATCs.