SH–3 POTLATCH RIVER BRIDGE REPLACEMENT
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/d7943cf0ff5b83a8908096223ba13410.jpeg)
CROSSING THAT BRIDGE INC.
ANTHONY DAVIS, PETER OSTERBERG, MATT THOMPSON, ZIXIANG YU
Introduction
• Built in 1955 north of Bovill
• Rebuild necessary to handle modern truck loads
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/9b6ec745637ffb1c3a819fd3a1ccde37.jpeg)
• Existing bridge was cast in place concrete tee-beam
• Supported by untreated timber piles of unknown condition
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/82208a08b41398d40ba5f36ac1e870d8.jpeg)
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/388b3ed575fffab72f48da6375c92330.jpeg)
• Rural location is heavily used by logging industry
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/efc0a6469625314dbef8e4aa3e07c6cd.jpeg)
Hydrology & Hydraulics
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/7056e62ea7cb21b389b205dd22dd77a9.jpeg)
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/ef1a63abffd026eafa0865b93d1bfb53.jpeg)
The analysis for the Potlach River Bridge was conducted using the Surface-water Model System (SMS).
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/4f71353f890f48da95f5dcb3068caba4.jpeg)
• Q1.5 Surface Water Elevation - 2895ft (71 cfs)
• Q50 Surface Water Elevation - 2896 ft (275 cfs)
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/8e6c363cb6378285d6ec0779ece70a98.jpeg)
• Q100 Surface Water Elevation - 2897 ft (325 cfs)
• Design Low Cord Elevation – 2899.45 ft
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/42418ff6da0acc3516adbde9309bedfc.jpeg)
• Riprap Design – Class IV, D50 = 15”, 30” Thick, 40 yd^3
Structural Design
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/4c24d8b3636168deb6302808a88849c3.jpeg)
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/9db923140d28a8549215228e0e259f6f.jpeg)
Cost Estimation
Transportation
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/2370581fe0886f4895310a05b6e7d648.jpeg)
• Bridge elevation raised by 1 ft
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/70d12e3afcfc4787d93e1a0769eb12ed.jpeg)
• Replaced 800 feet of road in order to taper from bridge width to road width (between green lines)
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/3d45a1f0eaaaab1181ee9577df01a4e4.jpeg)
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/8912119d78e4c9e5c86522bb97294f5e.jpeg)
• Vertical realignment within 80 ft of either side (between red lines)
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/de5b6299cee0916f85b13edb9d219910.jpeg)
• Fixed timing TTC signal Overview
• Reinforced Concrete
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/31128662259a9b4fef9e74be9f4caddf.jpeg)
• Width: 40 feet 10 inches
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/78e6d82fedc8be285000a251b6e7fc27.jpeg)
![](https://assets.isu.pub/document-structure/230420205720-5fed11fb372463a5e1fc76602ee65975/v1/c5af158beb303324d51951cbaf588cd9.jpeg)
• Span: 37 feet
• Deck thickness: 8 inches