SAI was responsible for the preliminary engineering, final design, and services during construction for the replacement of a structurally deficient bridge carrying S.R. 0053 over five tracks of the Norfolk and Southern Railroad Mainline in Cambria County, Pennsylvania.
Physical features:
- 324′, three-span, continuous steel multi-girder bridge over the Norfolk and Southern Mainline.
- Minimal amount of roadway approach (25′ approach slabs at each end) on a two-lane rural minor arterial with an ADT of 4,389.
- Deck consists of two 11′ lanes with 5′ shoulders for a deck area of 10,368 sq. ft.
Other features:
- 77 trains per day, steep rock slopes, and high-voltage overhead lines constrained site access and mobility.
- Significant coordination with Norfolk and Southern during design reduced issues during construction and during demolition to accommodate a high volume of rail traffic.
- Roadway profile and the structure depth were set to maximize the underclearance without compromising the structure or the sight distance.
- Maintained S.R. 0053 on its existing alignment and eliminated property takes, utility relocation, and additional earthwork.
- Traffic maintained via detour to expedite construction.
- Precast approach slabs were used to expedite construction.
- Abutment spread footing on soil to reduce construction time and cost.
- Bridge superstructure materials selected for reduced maintenance/repair and future impacts to railroad.
- Three-dimensional analysis of sharply skewed bridge performed for cross-frame design.
- Innovative erection method to expedite schedule.
- Successful project completion on time in 6 months with complete stakeholder satisfaction.
Client Owner: Pennsylvania Department of Transportation, District 9-0
Completion: 2014
Construction Cost: $3,400,000