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Approaches to Historic Bridge Rehabilitation Case Study #1. Hays Street Bridge Rehabilitation Patrick Sparks, P.E. Case Study #1. Hays Street Bridge Rehabilitation. San Antonio, Texas - viaduct over railroad, connecting historic neighborhood to downtown
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Approaches to Historic Bridge RehabilitationCase Study #1 Hays Street Bridge Rehabilitation Patrick Sparks, P.E.
Case Study #1 Hays Street Bridge Rehabilitation • San Antonio, Texas - viaduct over railroad, connecting historic neighborhood to downtown • Length: 1400-LF (1000-LF approach + 355-LF trusses) • Date and Truss Spans: • 1881 Whipple w/ Phoenix patent – 225-ft • 1881 Pratt through - 130-ft
San Antonio River Hays Street Bridge East side historic neighborhood Downtown Union Pacific RR
Case Study #1 Hays Street Bridge Rehabilitation • Completed: 2010 • Construction Cost: $3.2 M • Design Team: • Sparks Engineering, Inc. - Prime • Bender Wells Clark – Landscape Architects • Garcia & Wright – Civil • Joshua Engineering - Electrical • Client/Owner: City of San Antonio • Contractor: Jay-Reese Contractors
Case Study #1 Significant Issues Associated With Project • Deteriorated and obstructive concrete approaches • Iron truss evaluation using nondestructive methods • Corrosion of floor beams, U-bolts, stiffeners, pins, lateral struts built-up columns.
Case Study #1 Deteriorated and Obstructive Concrete Approaches • Obstruction • High level of deterioration • Major cost item • Street clearances • Accessibility compliance • Historic significance? • 30-ft width
Case Study #1 How the Deterioration & Obstruction Issue was Resolved • New Concrete Approaches: Cast-in-place concrete • Reduced width to 15-ft • Single piers, 40-ft spacing • Concrete through girder
Case Study #1 Evaluation and Rehabilitation of Iron Trusses 1881 Pratt and Whipple designs Phoenix wrought iron columns Cast-iron joint blocks Wrought iron eyebars Early laminated steel pins “Pneumatic Impact” method by Vern Mesler
Case Study #1 Floor beams, u-bolts, stiffeners, pins, lateral struts, built-up columns
Case Study #1 Lessons Learned/Conclusions • Sensitive and appropriate reconstruction of 1910 approaches saved money, made the project feasible, and improved the outcome for all stakeholders • Nondestructive evaluation was essential for unique 1881 cast-iron/wrought iron trusses. • Appropriate repair and preservation techniques were targeted, cost effective, not overly conservative, and durable.