1. Trail Bridges – A Common Sense Approach to Selecting Bridge Sites Presenter: James Scott Groenier, P.E. Project Leader, MTDC, WIT Prepared for: NOHVCC Conference Ontario, CA Ontario, CA March 17, 2005 March 17, 2005

2. Technology & Development 2 Introduction Site Reconnaissance Site Reconnaissance Geomorphology Concerns Geomorphology Concerns Hydrology and Hydraulics Hydrology and Hydraulics Alignment Alignment Environmental Concerns Environmental Concerns Design Loads Design Loads Trail Bridge Website Trail Bridge Website Summary Summary

3. Technology & Development 3 Site Reconnaissance Site Investigation - simple Site Investigation - simple

4. Technology & Development 4 Site Reconnaissance Site Investigation - Complex Site Investigation - Complex Streambed strata Floodplain widths Soil types Logs in stream Ice Damage Drift locations Etc

5. Technology & Development 5 Site Reconnaissance Site Survey Site Survey Center of Stream Edge of water Bottom of Bank Top of Bank Floodplains Trail Utilities Roads Drift / Ice damage Etc Survey upstream and downstream for 300 ft Survey approaches on both sides 150 ft Survey top of banks for 30 ft

6. Technology & Development 6 Site Reconnaissance Geotechnical Investigation Geotechnical Investigation BedrockLoam

7. Technology & Development 7 Geomorphology Concerns From Rosgens Field Guide for Stream Classification

8. Technology & Development 8 Geomorphology Concerns Stream Stability Stream Stability Bedrock - Type A Channel Stable Banks – Type B Channel Deposition Area – Type C Channel

9. Technology & Development 9 Geomorphology Concerns Bank Stability Bank Stability

10. Technology & Development 10 Hydrology and Hydraulics Waterway Adequacy Waterway Adequacy Hydrology Hydrology + Regression Equations from USGS Reports on Estimating Frequency and Magnitude of Floods = Flow (CFS)

11. Technology & Development 11 Hydrology and Hydraulics Waterway Adequacy Waterway Adequacy Hydraulics Hydraulics 1) Take CFS from Hydrology 2) Take Site Investigation info 3) Take Site Survey And Use a computer model such as HEC-RAS (River Analysis System) Or WinXSPRO And you get this….. HEC-RAS Example

12. Technology & Development 12 Hydrology and Hydraulics Flooding –Spring, Fall or rain on snow Flooding –Spring, Fall or rain on snow Good or Bad Location?

13. Technology & Development 13 Hydrology and Hydraulics Scour Scour

14. Technology & Development 14 Hydrology and Hydraulics Navigational Clearance Navigational Clearance 5 ft Minimum Required

15. Technology & Development 15 Alignment Horizontal Horizontal Straight 90 degree Bend

16. Technology & Development 16 Alignment Vertical Vertical Slight Grade Bottom of Sag Curve

17. Technology & Development 17 Environmental Concerns Fisheries Fisheries Spawning Areas, Fish passage Spawning Areas, Fish passage TES - Closures TES - Closures Salmon Salmon Bull Trout Bull Trout Cutthroat Trout Cutthroat Trout etc etc Wildlife Wildlife Nesting Trees, Rearing areas, etc Nesting Trees, Rearing areas, etc TES - Closures TES - Closures Indiana Bat Indiana Bat Bald Eagles Bald Eagles Northern Goshawk Northern Goshawk etc etc

18. Technology & Development 18 Environmental Concerns Ice Flow Ice Flow Floating Debris Floating Debris Falling Trees Falling Trees Falling Rocks Falling Rocks Excessive Snow Loads Excessive Snow Loads Avalanche Chutes Avalanche Chutes Springs/Seeps Springs/Seeps Wetlands Wetlands Others Others

19. Technology & Development 19 Design Loads Dead Loads Dead Loads Superstructure Superstructure Decking Decking Railing Railing Wearing Surface Wearing Surface Miscellaneous Miscellaneous Utility Lines Utility Lines Covers Covers

20. Technology & Development 20 Design Loads Live Load Live Load Pedestrian – 85 psf Pedestrian – 85 psf Equestrian Equestrian OHVs OHVs Snowmobiles Snowmobiles Mountain Bikes Mountain Bikes Vehicles Vehicles 5,000 width <6 ft 5,000 width <6 ft 10,000 6 ft<width<10 ft 10,000 6 ft<width<10 ft

21. Technology & Development 21 Design Loads Snow Loads – 0 psf to over 350 psf Snow Loads – 0 psf to over 350 psf SNOTEL sites – 550 to 600 in the West SNOTEL sites – 550 to 600 in the West Local Building Officials Local Building Officials http://fsweb.mtdc.wo.fs.fed.us/snow_load/ http://fsweb.mtdc.wo.fs.fed.us/snow_load/ Wind Loads Wind Loads Overloads Overloads Groomers Groomers 7600# - 18,000# 7600# - 18,000#

22. Technology & Development 22 Bridge Types Trail Bridge Catalog Trail Bridge Catalog Forest Service Intranet - http://fsweb.mtdc.wo.fs.fed.us/bridges/ Forest Service Intranet - http://fsweb.mtdc.wo.fs.fed.us/bridges/ http://fsweb.mtdc.wo.fs.fed.us/bridges/ Forest Service Internet - http://www.fs.fed.us/na/wit/WITPages/bridgecatalog/ Forest Service Internet - http://www.fs.fed.us/na/wit/WITPages/bridgecatalog/ http://www.fs.fed.us/na/wit/WITPages/bridgecatalog/

23. Technology & Development 23 Bridge Fabrication/Supply Structure produced by a certified Manufacturer for the type of material being used. Structure produced by a certified Manufacturer for the type of material being used. - See Contact Information For Wood and Steel Pedestrian and Trail Bridges at National Wood In Transportation Website

24. Technology & Development 24 Summary Site Reconnaissance Site Reconnaissance Geomorphology Concerns Geomorphology Concerns Hydrology and Hydraulics Hydrology and Hydraulics Alignment Alignment Environmental Concerns Environmental Concerns Design Loads Design Loads Trail Bridge Website Trail Bridge Website Questions? Questions?