INNOVATIVE DESIGN OF INTEGRAL PIERS PROVE COST-EFFECTIVE FOR THE MARTIN’S POINT BRIDGE

摘要

Stretching from Falmouth to Portland, Maine, Martin’s Point Bridge serves an important role in connecting these two communities. A Design-Build effort focused on cost-efficiency and multimodal safety has transformed the structure into the first multi-integral pier bridge in the state to use large precast/prestressed concrete girders. This accomplishment required supporting the 1,286-foot-long concrete girder bridge with eight integral piers and one traditional pier, located at the only deck expansion joint. Iterative designs and sensitivity analyses of materials and foundation conditions allowed the team to confidently construct these piers before the superstructure design was finalized. This paper explores the design considerations for the AASHTO Strength Limit States, the differing site conditions, varying pier heights, specific project requirements, and the constructability challenges anticipated and encountered during construction. Additionally, the paper discusses the challenges associated with designing for seismic and ice loads, the flexibility behavior and interactions at the integral connections, and the variation in material properties and stiffness. The innovative design of multiple integral piers with precast/prestressed girders at the Martin’s Point Bridge proved to be an economical structure for the Maine Department of Transportation and may serve as a model for future projects.