Federal Highway Administration State Transportation Innovation Council (STIC) Incentive funding
Iowa Department of Transportation
Iowa Highway Research Board
About the research
The use of prefabricated components has been continuously gaining momentum in bridge construction because of its numerous advantages over conventional cast-in-place construction methods. However, there are few, if any, projects that have utilized prefabricated components to construct the entire bridge column/footing/pile system because the sufficiency of suitable connections has not been adequately studied to ensure satisfactory performance at the system level. Therefore, this study was conducted to investigate a prefabricated bridge pier system suitable for accelerated bridge construction (ABC). The proposed system consists of a precast column, a precast pile cap, and steel H-piles. These components are integrally connected utilizing a column socket connection and pile socket connections that are preformed in the pile cap with corrugated steel pipes.
An experimental study was performed using eight specimens that modeled the full-scale connection interfaces, demonstrating that side shear strength in the column socket connection is sufficient to transfer large vertical loads from the column to the pile cap. Using a recently built bridge as the prototype, an outdoor test was subsequently conducted at half-scale, modeling a column/footing/pile system at a cohesive soil site. The footing in the test unit was supported by four vertical steel H-piles and four battered steel H-piles. To evaluate the system performance as well as the behavior of various connections and pile foundation, the test unit was subjected to different combinations of vertical and lateral loads. Throughout the test, the socket connections maintained fixity, confirming that the proposed system is an excellent alternative for routine use in accelerated bridge construction.