Steel Bridge Research, Inspection, Training, and Engineering Center
15. I-90 Mississippi River Dresbach Bridge
Donated by: Ames Construction in cooperation with Minnesota Department of Transportation (MnDOT)
Original Location: Over Mississippi River between La Crosse, WI, and Dresbach, MN
Opened in: October 1967
Replaced in: 2016
Donated to SBRITE: 2016
Structure Type: Welded Plate Girder (Two-Girder)
Total Bridge Length: 2,490 ft
Longest Span: 450 ft
Deck Width: 67.3 ft
Under Clearance: 62 ft
Deepest Section: 21 ft 10 in
Although the existing bridge had no weight restrictions and operated at an acceptable level of service, there were several issues with the bridge and surrounding roadways that motivated its replacement. These included the current interchange geometry, which created difficult and unsafe traffic movements for commuters, as well as structural deficiencies in the bridge—there was no structural redundancy (as per current guidelines), portions were beyond their useful life, and fatigue cracking had occurred. Other concerns included narrow bridge shoulders that did not meet state/federal standards, a lack of emergency vehicle bypassing or stalled vehicle storage, traffic buildup during parts of the day, and traffic safety issues, such as a higher crash rate on the I-90 curve and a pattern of crashes on the northbound Hwy 61 to eastbound I-90 ramp. Riverfront access was also a problem, with no access from southbound Hwy 61 or eastbound I-90. Additionally, I-90 serves as a regional river crossing, with the nearest crossings being five miles south and 24 miles north. The bridge was replaced in 2016.
The girders on the bridge were very deep and included longitudinal welded CJP web splices. The bridge specimens donated to S-BRITE showcase simple and effective retrofits, particularly at the intersection of welds on the lateral gusset plate details. This retrofit was most likely performed after the fracture of a girder on the Lafayette St. Bridge near St. Paul, Minnesota, in 1975. Other components obtained from the bridge include a pin and hanger assembly, as well as fixed and rocker bearings.
