Bridge Engineering Center

About the research

This study investigated the structural performance of fully encased steel H-piles used in bridge foundations, with a specific focus on the effects of unbraced pile height resulting from scour conditions. While concrete encasement is widely used to protect piles, its structural contribution is often excluded from axial capacity calculations in current design practice. This research aimed to evaluate the effectiveness of fully encased pile bents in enhancing pile stability and to refine an existing assessment tool for more accurate capacity estimations.

The project combined full-scale laboratory testing and finite element (FE) modeling. Two major tests were performed: a three-pile fully encased bent subjected to service-level loads and a single encased pile tested to failure. Results showed increased stiffness, increased load-sharing behavior, and a significant gain in axial capacity due to encasement.

Validated FE models were used to conduct parametric studies assessing the effects of encasement length, pile length, and axis orientation. Findings confirmed that full encasement and weak-axis restraint significantly improve axial performance.

This research supports the inclusion of concrete encasement in pile capacity evaluations and provides engineers with a validated tool for more resilient and cost-effective bridge foundation design.