Hays Street Bridge Rehabilitation Patrick Sparks, P.E. Approaches to Historic Bridge Rehabilitation Case Study #1 1

Hays Street Bridge Rehabilitation San Antonio, Texas - viaduct over railroad, connecting historic neighborhood to downtown Length: 1400-LF (1000-LF approach LF trusses) Date and Truss Spans: 1881 Whipple w/ Phoenix patent – 225-ft 1881 Pratt through ft Case Study #1 2

San Antonio River East side historic neighborhood Downtown Hays Street Bridge Union Pacific RR 3

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 4

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 5

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 6

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 7

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 8

Floor beams, u-bolts, stiffeners, pins, lateral struts, built-up columns Case Study #1 9

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. Case Study #1 10