Modified Sheet Pile Abutment for Low-Volume Road Bridge

Steel sheet piling, typically used for retaining structures in the United States, is a potential alternative for use as the primary component in low-volume road (LVR) bridge substructures. To investigate the viability of sheet pile abutments, a demonstration project was performed in Black Hawk County, Iowa. The project involved construction of a 40 ft single-span bridge utilizing axially loaded steel sheet piling as the primary foundation component. The site selected for the project had primarily silty clays underlain by shallow bedrock into which the sheet piling was driven. An instrumentation system (consisting of strain gages, deflection transducers, earth pressure cells, and piezometers) was installed on the bridge for obtaining service load test data as well as long-term performance data. This paper presents documentation of the design and construction of the demonstration bridge in Black Hawk County as well as an analysis of the design procedures used through information collected during load testing. Preliminary results indicate that steel sheet piling is an effective alternative for LVR substructures, and future demonstration projects are planned to investigate different sheet pile abutment alternatives for varying site conditions.