Transcript Document
Client: City of Pittsburgh, Brighton Heights Community Objectives: Develop a pedestrian/bicycle bridge reconnecting Brighton Pier Design: 14’x4’ with 2’ radius rounded edges. #6 reinforcement bars and #4 tie bars placed 4” from pier edges. There will be four total piers. The two piers on the West side of the bridge will be 20’ high while the piers on the East side will be 10’ and 5’ high. Heights to Riverview park. Location: Brighton Heights, Pittsburgh, Pennsylvania. Will connect Davis Avenue to Riverview Park spanning 396’ over Woods Run Avenue at approximately 80’ high. Recommended soil testing: • • • • • • Scope of Work: Structural Design Geotechnical preliminary designs and recommendations Project management plan Cost estimate Project Schedule Bridge History: Originally constructed in 1898, the Davis Avenue Bridge would be rehabilitated in 1986 before Aerial view of the site showing the proposed being closed to traffic in 2001 and bridge site. eventually demolished in 2009. • • • • • AutoCAD profile view of proposed bridge design. AutoCAD cross sectional view of design. AutoCAD plan view of pier design Estimate: Carried out a detailed estimate for each part of the project. Top- Detailed estimate of steel superstructure Bottom- Detailed superstructure of pier and abutment work Overview: Steel arch bridge consisting primarily of double angles. The two sides of the arch will be connected creating an 11’ width between them. Loading guidelines: ASHTO LRFD 2012 Bridge Design Specifications 6th edition along with ASHTO LRFD Guide Specifications for Pedestrian Bridges (2009) Truss member design: Using a STAAD model of the bridge, load cases were entered and axial forces were found in each member. Girders and wind columns were treated as beam columns. Bracing design: Again using the STAAD model wind loading was applied to the bridge. Axial loads were found and members were selected. All diagonal members were treated as pure axial loaded members while all other members were treated as beam columns. Transverse bottom cord design: Designed in order to provide adequate stability and force transfer between the two arches and into the foundation. Connections: Typical connections were designed for bolt strength, block shear, hole bearing, and slip. Eight connections commonly used in the bridge design were created. Floor beams: Floor beams were designed to carry the moment from the combined live, dead, and snow load. Atterberg limits Triaxial testing Unconfined compression Consolidation Direct Shear Hydraulic Conductivity Background: Supplied by Composite Advantage in Dayton, Ohio, the fiberglass decking provides the necessary structural stability while provided numerous benefits over a concrete decking. Benefits: • Light Weight- Weighing anywhere between 5 to 10 psf, the fiberglass deck weighs only 10 to 20 percent of an equivalent concrete deck. • Durability- The wearing surface can protect against corrosion for over 50 years with minimal maintenance. • Accelerated construction- The prefabricated panels can be placed using lightweight machinery at a much quicker rate than that of a concrete deck. Our Design: The Brighton Heights Pedestrian Bridge will utilize a 4” deep fiberglass decking. There will be 12 panels 8’x32’ and the final panel will be 8’x12’. The deck will include a wearing surface along with prefabricated curbs. Connections will be bolted to the bottom and clip onto the floor beams spaced every 8 feet. The use of fiberglass will enable the decking to be placed in a matter of days, speeding up construction time, decreasing the labor cost, and allowing Woods Run Avenue to reopen quickly. Top- Picture of Composite Advantage fiberglass deck Bottom- Diagram of typical deck to floor beam connection Below- Full project schedule Members of Allegheny Bridge Consultants would like to thank the following people who aided in our design . process: Dr. John Oyler, Mr. Patrick Miner, Dr. Kent Harries, Professor Joseph Beck, Dr. Dan Budny, Dr. Karl Lewis, Andrew Loff and associates at Composite Advantage, community members of the Brighton Heights Community Forum