Interstate 40 Crosstown Expressway
Oklahoma City, Oklahoma
Bridgefarmer provided plans, specifications and estimate documents for all of the railroad design of this controlled access freeway project including a 3,265-foot shoofly, a 766-foot shoofly bridge, a 777-foot permanent bridge, and a new BNSF-WATCO rail connection.
This project was an award-winning effort, with Bridgefarmer recieving the National ACEC Award of 2009 and the Texas CEC Award of 2008. To create this very busy bridge, we employed the tallest girters used at 16' tall.
Original or Innovative Application of New or Existing Techniques:Bridgefarmer was selected to design a temporary shoofly and permanent structure for the BNSF railway and the Oklahoma Department of Transportation (ODOT). The main objective was to keep the BNSF railway, Union Pacific Railroad, Cottonseed Mill and several other short-line railroads in operation while the existing rail line and bridges were removed and replaced with new structures. The current tracks are extremely busy and carry a train every 30 minutes from various railroad carriers. An innovative design was required to address these constraints. Bridgefarmer’s engineers decided to use identical concrete spans (Quick Built beams) that could be manufactured elsewhere and trucked onto the job site. These spans would be laid end to end for several hundred feet to quickly form the shoofly bridge without compromising the short-line railroads, UPRR or BNSF train schedules.
Future Value to the Engineering Profession:By selecting this repeat process of separate identical simple spans of double box girders directly connected to tracks, Bridgefarmer’s design engineers set a precedent for other engineering teams to follow on future projects. This makes it possible for these double box beams and the steel HP piles to be removed and reused at other locations for years to come. Since this bridge was used temporarily and was not destroyed, it saved $10 million of capital cost due to high salvage value and NO train delays. This process reduced the capital cost to ODOT and produced salvage value of material, making the railroad agreement a convenient process.
Social, Economic and Substantial Design Considerations:The old and new tracks are elevated due to roadways and other rail tracks running beneath them. In order to complete this project in a timely manner, the new shoofly was built using solid repeat spans. Due to the geometric constraints and skew angles of the shoofly bridge, the design required three different types of spans. For this 2000-foot long bridge only two types of concrete double box girders were used and one skewed steel span was used. Looking at the construction pictures, one can see starting from the first stages of the project that steel sheet pile walls were driven into the ground to retain the elevated earth embankment. To control the deflections at the top of these walls, a 2-inch diameter rod was used every few feet to work within the constraints of the right-of-way. This gave the engineers room to operate in a very confined area. The biggest challenge on the project was to keep the existing railroad and roadways in service and make room for the proposed I-40 at a new alignment. In order to make this happen, several railroad bridges were rebuilt and a complex railroad traffic control plan was developed to keep the rail traffic and highway traffic open at all times. The new shoofly bridge had to accommodate the traffic underneath on existing streets and railways.
Complexity:This project was very complex due to the railroad traffic control plan developed to keep rail traffic, highway traffic, local roads emergency vehicles and construction area traffic operating at all times during construction. The construction workers had to work in close proximity to the present railroad tracks and an adjacent high-speed arterial roadway (Shields Blvd.). The construction of the shoofly was completed and the first train used the shoofly on June 4, 2007. Now the original tracks and bridges can be removed and a new set of permanent bridges and tracks can be built. This shoofly construction required the demolition and removal of two existing BNSF concrete underpasses and approximately 40,000 cubic yards of dirt, and the relocation of several railroad turnouts, storage tracks and loop tracks for switching purposes.
Exceeding Client/Owner Needs:Bridgefarmer was the lead bridge and track engineer for this project. The unique application of similar concrete double box girders on steel H – piles is an old idea that saw an innovative application on this project.
This project is unique because the structure was designed and built in less than six months and saved taxpayers millions of dollars. It included complex railroad coordination, traffic control, final alignment, grading and drainage, steel and concrete bridge layout, a shoofly design, track work and retaining wall design and construction, with a high overall salvage value.