Disraeli Bridges Rehabilitation Project Description City of Winnipeg Public Works Department
Introduction Overview - Project Limits - Description of Bridges - Current Condition Assessment - Conceptual Design - Structural Evaluation - Traffic Management During Construction - Public Consultation to Date - Construction Schedule
Project Background & Limits • Opened in 1960 • Roughly 2 km of Road & Bridge • Red River Bridge – 320 m (1050 feet) • CPR Overpass – 390 m (1280 feet)
Disraeli Aerial Overview
Overpass Bridge Elevation
Overpass Cross Section
River Bridge Elevation
River Bridge River Spans
River Bridge Land Spans
Original Construction
Disraeli Bridges Rehabilitation Condition Assessment
Maintenance History • Early 1970’s – Open Grid Deck Infilled with Concrete & Asphalt Wearing Surface Installed. Girders were Painted. • 1979 – Concrete Median Barrier Installed • 1984 – Asphalt Wearing Surface Replaced with other Repairs to Structure • 2004 – Concrete Pier Repairs • 2004 – 2008 Structural Steel Deck Repairs
Condition Assessment Components • • • Bridge / Overpass Structures Roadways Geometry Structural Evaluation Road & Structure Safety Pedestrian Safety & Accessibility
Piers / Abutments
Bearings
Girders
Bridge Deck
Sidewalk & Barriers
Geometry • Insufficient Radii on Roadway North of the Bridge and South of the Overpass • Existing On/Off Ramps Do Not Meet Current Geometric Requirements
Geometry
Road & Structure Safety
Pedestrian Safety & Accessibility • Steep, Narrow Sidewalks with Potential Risk of Tripping Hazards • Limited Bicycle Facilities • Lack of Separation from Traffic
Pedestrian Safety & Accessibility
Summary of Deficiencies • Piers/Abutments and Bridge Deck are Severely Deteriorated • Limited Girder Corrosion • Bridge and Roadway Geometry • Universal Design and Overall Accessibility
Disraeli Bridges Rehabilitation Conceptual Design
Design Criteria • Structural Design – CSA-S 6 – CL 625 Loading & 62. 5 T where possible • Geometric Design – TAC Geometric Design Guide – City of Winnipeg Standard Practice • Universal Design – City of Winnipeg Accessible Design Standards
Maintenance Considerations • Zinc-Metallize Girders • Chloride Extraction of Piers & Abutments • Possible Replacement of Select Piers & Abutments • Automated Anti-Icing System
Concept A - Minimum
Concept B Two Sidewalks
Concept C One Wide Sidewalk
Geometry North of Bridge
Red River Bridge
Between Bridges
CPR Overpass
Main Street to Overpass
Structural Evaluation • Original Design Based on 1950’s Codes and Standard Practice • Previous Load Ratings and Load Testing in Late 1970’s and Early 1980’s • Update to Current Design Codes and Truck Loading Where Possible.
Structural Evaluation
Over Height Damage 2006
Physical Testing • Steel Coupons Taken From Damaged Girder and Three Other Locations. • Verify the Steel Properties: – Meets all requirements of ASTM A 373 -58 T – Does not meet current notch toughness requirements for new construction. – Modern notch tough steel did not exist until the 1970’s.
Girder Rehabilitation Considerations • 36. 5 T posting governed by stress in River Bridge plate girder spans. • Girders have infinite fatigue life at 36. 5 T. • Very low ADTT at about 1% of ADT • Structures not fracture critical. • Brittle fracture affected by: – Triaxial state of stress (bad detailing) – Low temperature – Rapid rate of loading
Preliminary Design Findings • Wide flange girder spans can be rehabilitated & strengthened to CL-625 • Not feasible to strengthen river span plate girders to CL-625 or 62. 5 T. Options are: – Rehabilitate plate girders and post bridge between 36. 5 T and 62. 5 T. – Replace plate girder spans. Allows for profile and cross section enhancements.
Disraeli Bridges Rehabilitation Traffic Management During Construction
Impacts on Traffic During Construction • • • Vehicular Traffic Capacity Pedestrian & Cyclist Accessibility Transit & Emergency Services Trucking Industry Local Business Rail and Marine Traffic
Traffic Management Options • Partially Open • Full Closure
Risks Associated With Partially Open Option • • Staged Construction Longer Construction Schedule Delays Vibration-Induced Cracking Due to Traffic
Traffic Management Conclusions • Partially Open option is not practical. • Full Closure option is recommended for traffic management during rehabilitation of the Disraeli Facility. • Further work on a full closure traffic management plan is being undertaken to deal with community access, traffic management, and transit.
Disraeli Bridges Rehabilitation Public Consultation
Public Consultation Process • • • Key Stakeholder Advisory Committee (SAC) News Letters Phone and Mail-in Surveys Public Open Houses Report on Findings
Construction Schedule • Construction period estimated at 16 to 24 months. • Limit total bridge closure to 12 to 16 months.
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