Background information
This Section of the Website is intended to provide relevant information resources relating to past studies, engineering, and corrective actions pertaining to the bridge structure. Please provide comments in the "INPUT" section of the website if you are aware of other past factual information related to Cascade Bridge.
Cascade Bridge, constructed in 1896, was listed to the National Register in 1998 under Criterion C. The bridge is described as a combination of pinned Pratt trusses and a pinned Baltimore truss. The bridge has also been the subject of Historic American Engineering Record (HAER) documentation completed in 1995. While not evaluated as a contributing property to the Crapo Park and Arboretum Historic District, Cascade Bridge was constructed to allow access to the park, and therefore, it has associations to the historic district. The bridge was deemed structurally deficient for vehicles and it was closed for vehicular use in 2008. In its idleness, the bridge deteriorated further and was closed to pedestrian traffic in 2019. The most recent engineering study of the structure, conducted in 2012 by Shuck-Bitson, Inc., concluded that the bridge is in poor/critical condition.
Cascade Bridge, constructed in 1896, was listed to the National Register in 1998 under Criterion C. The bridge is described as a combination of pinned Pratt trusses and a pinned Baltimore truss. The bridge has also been the subject of Historic American Engineering Record (HAER) documentation completed in 1995. While not evaluated as a contributing property to the Crapo Park and Arboretum Historic District, Cascade Bridge was constructed to allow access to the park, and therefore, it has associations to the historic district. The bridge was deemed structurally deficient for vehicles and it was closed for vehicular use in 2008. In its idleness, the bridge deteriorated further and was closed to pedestrian traffic in 2019. The most recent engineering study of the structure, conducted in 2012 by Shuck-Bitson, Inc., concluded that the bridge is in poor/critical condition.
Cascade Bridge underwent repairs in 1953 including new truss bearing shoes, new horizontal bracing, reinforcing of steel piers, and reinforcing of some diagonal eyebars. From 1960 to 1984 numerous other repairs occurred including the following:
- The 5” steel roadway deck grating was installed in 1964;
- Replacement of roadway deck joints;
- North abutment bearing seat repairs and reinforcement of southeast abutment wing;
- Installation of lateral bracing stiffener plates at panel points, reinforcing of some diagonal eyebars, seal welding of eyebar ends at panel points;
- Cutting of holes in truss members to drain water;
- Replacement of missing steel lacing with plates;
- Clean and paint entire bridge;
- Pier 2 steel repairs and concrete retaining wall at Pier 2;
- Removal of existing sidewalk and exterior rail, and replacement with concrete sidewalk on corrugated steel deck, new sidewalk expansion joints, new exterior sidewalk rail;
- Removal of laminated wood deck, and replacement with 5” open steel deck;
- Removal of steel floorbeam bolsters, replacement with new steel wide-flange beams on tops of existing floorbeams;
- Removal of shallow stringers, replacement with new steel wide-flange stringers;
- New roller bearings at Piers 1 and 3;
- New jacking posts at Pier 1 for bearing replacement;
- New floorbeam at north abutment; and
- Floorbeam repairs at south abutment.
Downloadable information provided by the City of Burlington is available by clicking on the file links below.
2006_bridge_inspection_report.pdf | |
File Size: | 606 kb |
File Type: |
2012_cascade_bridge_rehabilitation_evaluation__including_appendix__-_shuck-britson_inc.pdf | |
File Size: | 6669 kb |
File Type: |
Summary Points from Cascade Bridge Rehabilitation Evaluation, September 2012, by Shuck-Britson Inc.
-With federal funding planning and design timeframe: Estimated 24 Months
-Due to the limited scope of the 2012 evaluation, the report noted that there would be additional repairs required to the piers, abutments, and truss compression members that were not accounted for in the estimate.
-The evaluation was based on the last in-depth inspection conducted in 2008. It is likely that there has been substantial deterioration in the last 12 years.
- Prepared by Iowa Registered Professional Engineer
- Purpose: Evaluation for Rehabilitation
- Site Visit Observations by Iowa Registered Professional Engineer
- 5-inch Steel Roadway Deck Grating Appeared to be in Generally Good Condition
- Recommendation: "Because of the advanced age and deteriorated condition of the Cascade Bridge noted previously in this report, as well as the unknown fatigue cycle history, the structure should be closed until repairs can be implemented, as it is susceptible to sudden, catastrophic failure of the tension members."
- Cleaned and Painted as Part of Previous Repairs (Previous Paint Layer Removal Unknown)
- Sampling of Paint Topcoat and Primer Coats Needed to Determine Lead and Chromium Content
- Recommends Full Paint Removal and Repainting of Entire Bridge Framing: Cost of $2,056,000 (Existing Paint Hazardous); Cost of $1,645,000 (Existing Paint non-Hazardous)
- Rehabilitation Cost in 2012 Dollars: $6,105,000 (Load Limit of 20 Tons with Life Expectancy of 50 Years); Adjusted for Inflation to 2020 Dollars Based on Consumer Price Index: $7,204,072
- Rehabilitation Cost Plus Future Maintenance: $8,588,000 (Net Present Cost); Adjusted for Inflation to 2020 Dollars Based on Consumer Price Index: $10,133,887
- Rehabilitation Preliminary and Final Design Timeframe: 12-18 Months at Fee Range Between 8 and 12 Percent of Rehab Cost
-With federal funding planning and design timeframe: Estimated 24 Months
-Due to the limited scope of the 2012 evaluation, the report noted that there would be additional repairs required to the piers, abutments, and truss compression members that were not accounted for in the estimate.
-The evaluation was based on the last in-depth inspection conducted in 2008. It is likely that there has been substantial deterioration in the last 12 years.