CTRE is an Iowa State University center, administered by the Institute for Transportation.

Address: 2711 S. Loop Drive, Suite 4700, Ames, IA 50010-8664

Phone: 515-294-8103
FAX: 515-294-0467

Website: www.ctre.iastate.edu/

Iowa State University--Becoming the Best

Testing and Long-Term Monitoring of 9th Street Bridge Over I-235 in Des Moines: Integral Abutments Supported on Steel Pile/Concrete Drilled Shaft in Glacial Clay


Principal investigators:

Co-principal investigators:

Project status


Start date: 04/15/06
End date: 04/30/10


Sponsor(s): Iowa Department of Transportation

About the research


The 9th Street Bridge in Des Moines is the first bridge in Iowa that uses a unique integral abutment design. The integral abutments are supported on steel H-piles that are embedded into concrete drilled shafts, which are seated in glacial clay. This unique design was developed in an effort to address environemental concerns--namely vibrations from pile driving--while also providing a long-lasting stucture in the form of a jointless bridge. Although this innovative work is promising, it is unproven and will not become a common option unless adequate testing and monitoring are performed to validate design and behavior assumptions. A total of three pile/shaft elements will be instrumented and monitored over a minimum two-year period.