In Hempfield County Pennsylvania there stands a dual span composite steel I-beam bridge, located on the Pennsylvania Turnpike on Route 66. The twenty year old bridge according to the Federal Highway Administration (FHWA) is structurally obsolete and outdated. The Civil Engineering project design team of Tim Walkowich, Allison Pollio, Dave Wysocki, Kathleen Evangelista, Jacob Gulko, and Kadijah Thomas set out to redesign this bridge using the latest and most current Load Resistance Factor Design (LRFD).
Using LRFD Specification and design methods allowed the team to determine that the bridge could be redesigned with the support of only four steel members instead of the current five which adorn the bridge’s superstructure. Improving the bridge required a complete geotechnical, hydrological, and structural evaluation. The soil around the bridge was found to be layered sand and clay with a bedrock composed mainly of shale sandstone at a depth of approximately 23 feet. Current methods along with topographical maps were used to determine and improve the bridge’s design against storm cycles occurring over 50, 100, and even 500 year time cycles. All structural members were designed in accordance with the latest American Association of State Highway and Transportation Officials (AASHTO) LRFD Bridge Design Manual, and the New Jersey Department of Transportation (NJDOT) Bridge and Highway Superstructure Design Manual.
The bridge consists of two spans, both 160 feet. One span overpasses Route 6066, and the other passes over the Brush Creek. Steel composite bridges are contrasted of two separate building materials fashioned together by steel girders and reinforced by concrete. This allows for a product of unified material that holds the bridge as one piece instead of two separate materials which could have the potential to move independently from one another due to vehicle and bridge dynamics. The TCNJ team worked hard on the bridge project showing great pride in their work and care in considering all the natural and human factors which could affect the structural integrity of their design.
Learn More
- Federal Highway Administration
- American Association of State Highway and Transportation Officials
- LRFD Bridge Design Manual
- New Jersey Department of Transportation
- Bridge and Highway Superstructure Design Manual