2019 APWA of Southern Arizona – Project of the Year
2018 ACEC Arizona – Engineering Excellence Clifford Sawyer Award
2018 ACEC Arizona – Engineering Excellence Grand Award
Structural Design Dudleyville, Pinal County, Arizona
In 1957, ADOT had abandoned Valentine Road in the unincorporated community of Dudleyville to Pinal County. Due to the size of the structure, a 60-year-old single-span wooden bridge went uninspected and neither ADOT nor the County had plans or as-builts on file.
Upon recent rediscovery of the bridge in 2015 by Pinal County, it contracted with Structural Grace to perform a load rating analysis of the wooden Valentine Road Bridge, prepare a bridge alternative cost analysis, and provide PS&E documents for the superstructure replacement. After determining an existing load rating of five tons, SGI evaluated bridge replacement alternatives considering the scour, environmental impacts, traffic impacts, schedule, and overall cost for the three alternatives: multi-cell precast box culvert, conspan structure with wingwalls, and superstructure replacement. Ultimately, the superstructure was replaced with a new precast pre-stressed voided slab superstructure utilizing the innovative Geosynthetic Reinforced Soil-Integrated Bridge System (GRS-IBS) generated from FHWA’s “Every Day Counts” initiative. GRS-IBS is a fast, cost-effective method of bridge support that blends the roadway into the superstructure to create a jointless interface between the bridge and approach. As a result, the bridge was completed without having to satisfy additional environmental, biological, or historical requirements, saving nearly nine months in the design schedule and reducing design costs. The new design utilized the existing concrete abutments and grouted stone wingwalls, thus reducing removal costs, adding additional scour protection, and preserving the aesthetic history. Bearings and deck joints were eliminated, thereby reducing future maintenance costs, and the new structure provided a larger hydraulic opening to slow the flows and reduce potential scour. The existing bridge was removed and replaced in 30 days.
“Structural Grace, Inc. and its project team worked diligently with Pinal County staff and affected agencies throughout the duration of this project. Their multi-disciplinary approach and adaptive strategies for tackling the issues that surfaced during the course of the design allowed this project to meet all of our expectations. Structural Grace, Inc. exhibited professionalism and competence throughout the life of this project and repeatedly met or exceeded our professional needs.” — Scott Bender, Pinal County Engineer