Analysis and Testing of a Buried Composite Arch Bridge

A new hybrid composite bridge system was recently used to rebuild a bridge in Pittsfield, Maine. The 34' span Neal Bridge replacement uses a rigidified FRP concrete tube arch filled with concrete and buried, forming a concrete culvert-type structure with neither time consuming formwork construction nor expensive delivery of large pre-cast components. This first-of-its-kind bridge was installed under the auspices of the Maine Department of Transportation. Design and load testing was performed by the University of Maine's AEWC Advanced Structures and Composites Lab. The bridge was built for a cost comparable to precast concrete structures in similar environments and the load test showed large amounts of reserve capacity. Also discussed are current designs that reduce the installed cost and future plans to allow for alternate geometries including longer spans and girder and moment frame construction.