Project Summary

The Stimson Bridge carries State Route 5 over the Little Ossipee River, connecting the towns of Waterboro and Limerick. This project included design of a new 168′ long two-span horizontally curved steel plate girder structure to replace the structurally deficient existing 3-span, 135′ long concrete tee-beam bridge. Replacement substructure units consist of a mass concrete center pier and integral H-pile abutments. Design considerations for the integral abutment structure included variable depths to bedrock between the abutments, a 5% roadway superelevation across the bridge, and the horizontal curvature of the bridge (centerline of roadway radius of approximately 1,000’). Shallow depth to bedrock at the Limerick abutment required over-coring of the bedrock sockets for those piles, effectively increasing the unbraced pile lengths to match those of the Waterboro abutment to create uniform pile stiffness and behavior between the two abutments. This project also included final design of improvements to approximately 500’ of approach roadway, including improvements to the adjacent Beaver Brook Road intersection. This project was completed for MaineDOT as an assignment under a Bridge Design General Consultant Agreement (GCA).