Montana Department of Transportation

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Research

Concrete-Filled Steel Tube to Concrete Pile Cap Connections – Further Evaluation/Improvement of Analysis/Design Methodologies

The Montana Department of Transportation has found concrete-filled steel tube (CFT) piles connected at the top by a concrete pile cap to be a very cost-effective support system for short and medium span bridges. This type of system offers low initial cost, short construction time, low maintenance requirements, and a long service life. While the gravity load performance of these systems is well understood, their strength and ductility under extreme lateral loads (e.g., seismic events) is more difficult to reliably predict using conventional design procedures. The proposed research aims to further develop newly established design and analysis methodologies, and to ultimately ensure the desired bridge performance.

The primary objective of this project is to further validate/improve MDT’s CFT to concrete pile cap connection design/analysis methodologies, and to ensure the efficacy of these methodologies for a wide variety of potential design configurations. This research will include physical tests of scaled specimens, which may include specimens with variations in cap dimensions, CFT diameter, or number of embedded piles. Additionally, the use of battered piles or precast concrete pile caps in this system may be explored experimentally. The exact scope of this project will be further developed through collaboration with the technical panel at the next stage of the proposal.

Please contact Sue Sillick ( or 406-444-7693) for more information.