The third model incorporated another innovative design in the piers. Similar to the previous models, the bridge was supported on three, two-column piers. Two innovative ideas were studied in the bridge:
- All three piers in Model 3 incorporated round reinforced concrete columns with FRP jackets
- Accelerated bridge construction techniques and details were utilized.
A different detail was used in each pier. In pier 1 the columns consisted of cast-in-place concrete-filled glass FRP tubes in which the tubes served as the formwork and provided a part of the flexural and shear capacity and the entire required confinement. The fibers were in the +/- 55-degree angles. Longitudinal steel bars were anchored into the cast-in-place footing. In pier 3 similar columns were used but they were precast and placed into a precast footing. In both piers 1 and 3 the connection to the superstructure consisted of steel pipe pins. Pier 2 was made with segmental reinforced concrete columns wrapped with carbon FRP to provide confinement and shear capacity, with fibers in the transverse direction of the column. The earthquake loading protocol was similar to those used in bridge models 1 and 2.
Data and documentation
The final test in the 4-Span Bridge project received media coverage from outlets including ScienceDaily and Science Newsline, as well as local media such as the Reno Gazette Journal and KTVN News.