This spectacular Post-Tensioned Precast Concrete Bridge is a replacement for the I35W Mississippi River Bridge that collapsed in August 2007. A total of 54 Disktron Bearings were installed, 5 of which were designed for uplift, with a vertical capacity of 1,200 to 5,800 kips. The project was completed in April 2008.
New Bridge Design:
General Contractor: Flatiron Constructors/Manson Construction, Joint Venture
Consulting Engineer: Figg Bridge Engineers, Inc.
Cost of new bridge: $234M
Schedule: October 2007 – December 24, 2008 (437 Days)
New Bridge Facts:
Segmental Concrete Bridge, 189’ wide-10 lanes (old bridge was 113’-8 lanes). 13’ and 14’ wide shoulders (no shoulders on old bridge). Light Rail Transit ready. 1,223 foot span (old bridge was 1,907 foot span).
Bridge Bearings:
R.J. Watson, Inc. manufactured 54 disc bearings.
Fabrication time for I-35W bridge: Nov. 27 – Apr. 4
Quantity/Type/Size of bearings:
- Vertical Load ranged from 1,200 kips to 5,800 kips
- Horizontal Load ranged from 8% to 14% of vertical load
- Longitudinal Movement = 20”
- Transverse Movement ranged from 0.125” to 2”
- Service Rotation = 0.02 radians
8 of the disc bearings are designed to resist uplift forces during a factored load case however a positive reaction was noted for all service cases.
Disc Bearing Advantages:
Low Maintenance, Easy to Inspect, Low Profile, Excellent Performance History, Excellent Low Temperature Performance, Simple Design, can accommodate very high vertical and horizontal loads, can restrict uplift forces, can accommodate high rotation, modified for seismic isolation, and force distribution.