Three sister bridges

-- Presentation by AAron Colorito

Dinner Meeting - Thursday January 30^th – Earn 1 PDH

Cefalo’s Banquet & Event Center 428 Washington Avenue in Carnegie

Social 5:00pm, Dinner 6:00pm, Presentation 7:00pm

Members $55, Non-Members $65, Government/Student $25

For more information contact SEI.Pittsburgh@gmail.com

The Roberto Clemente (6^th Street), Andy Warhol (7^th Street), and Rachel Carson (9^th Street) Bridges cross the Allegheny River in downtown Pittsburgh, Pennsylvania. Collectively known as the Three Sisters Bridges, the eyebar-chain self-anchored suspension bridges comprise the only trio of identical, side-by-side bridges in the world and were the first self-anchored suspension bridges in the United States. Constructed in the mid-1920s, the Three Sisters Bridges are essentially identical in design and detailing; however, they have experienced different types of deterioration and structural issues over their lifetimes. The bridges were rehabilitated over the course of three sequential projects. This presentation presents lessons learned over the course of the projects that can be useful for future rehabilitations and repairs of riveted steel bridges. Types of repairs included deck replacement, steel framing repair and replacement, tie-down system replacement, eyebar and pin nut replacement, making stringers composite through a buckle plate floor, and general rivet replacement.