1. Dennis L. Edwards Tunnel
Constructability Review
February 5, 2010
East Portal looking west circa 2001
Nathan K. Potter, PE
Project Manager
Oregon Department of Transportation
Randy G. Hinderer, PE
Senior Project Manager
LOCHNER
East Portal looking west circa 1940

2. Agenda
Introduction
Project Overview
Constructability Review Agenda

3. Dennis L. Edwards Tunnel
Originally called the Sunset Tunnel, construction was completed by the Works Progress Administration (WPA) in 1940.
The tunnel was renamed after Dennis Edwards, a member of the District 2A staff who was killed during inspection activities in January 1999 when part of the tunnel collapsed. Closure and detour duration was approximately 5 weeks.
Technical Data
US26 (Sunset) (Highway No. 047)
Mile point: 40.9
Bridge No
Posted Speed: 55 MPH
Average Daily Traffic (ADT): 6,700
Average Daily Truck Traffic (ADTT): 12% (804)

4. Dennis Edwards Tunnel
(MP 40.90)

5. Project Objectives Reline the tunnel Lighting Improvements
Drainage Improvements
Freight industry has asked to ODOT to consider vertical improvements
Bicycle/Pedestrian Improvements

6. Historic Considerations
The completed masonry portal
Model of the West Portal
The builders
East Portal looking west

7. Local Tunnel Detour Timber Road Oregon 47 Columbia County
Washington County
Oregon 47
Length Restricted
65’ Truck-tractor and Semi-trailer
Total Detour Route = 26 Miles
Distance on US 26 = 11 Miles
Additional Distance = 15 Miles
Timber Road
10 miles
16 Miles
OR 47 1
11 Miles 2
Dennis Edwards
Tunnel
(MP 40.90) 1
Tillamook Railroad
Over Crossing
(MP 42.50) 2

8. Regional Detours (Seaside to I-405)
US 30 = 115 Miles
US 26 = 79 Miles
Difference 36 Miles

9. Tunnel Profile

10. Edwards Tunnel, West Portal, March 2000

11. Edwards Tunnel, STA 0+00 Looking East, March 2000

12. Edwards Tunnel, STA 0+50 Looking East, March 2000

13. Edwards Tunnel, STA 1+00 Looking East, March 2000

14. Edwards Tunnel, STA 1+50 Looking East, March 2000

15. Edwards Tunnel, STA 2+00 Looking East, March 2000

16. Edwards Tunnel, STA 2+50 Looking East, March 2000

17. Edwards Tunnel, STA 3+00 Looking East, March 2000

18. Edwards Tunnel, STA 3+50 Looking East, March 2000

19. Edwards Tunnel, STA 4+00 Looking East, March 2000

20. Edwards Tunnel, STA 4+50 Looking East, March 2000

21. Edwards Tunnel, STA 5+00 Looking East, March 2000

22. Edwards Tunnel, STA 5+50 Looking East, March 2000

23. Edwards Tunnel, STA 6+00 Looking East, March 2000

24. Edwards Tunnel, STA 6+50 Looking East, March 2000

25. Edwards Tunnel, STA 7+00 Looking East, March 2000

26. Edwards Tunnel, STA 7+71.5 North Side, March 2000

27. Edwards Tunnel, East Portal, March 2000

28. Edwards Tunnel, Looking East from East Portal, March 2000

29. Edwards Tunnel, North Side of East Portal, March 2000

30. System Drainage

31. Alternative 1: Lining Only
Replaces the tunnel lining
Replaces / rehabilitates the tunnel PCC floor and drainage system
Installs new lighting system
Existing portals and stone masonry will remain untouched.

32. Alternative 2: Floor Lowering
Clearance achieved by removing the existing lining consisting of steel and timber sets, removing the rubble and gravel behind the existing liner, and replacing the liner with rock bolted shotcrete directly to the exposed siltstone bedrock.
Roadway elevation will be lowered throughout the tunnel approximately 2.5 feet to achieve vertical clearance, transitioning back to existing grade approximately 700 feet on both tunnel approach sections.
Existing portals and stone masonry will remain intact, however underpinning the portal masonry and associated concrete wall structure with new footings will be necessary.

33. Alternative 3: Portal Raising
Clearance achieved by removing the existing lining consisting of steel and timber sets, removing the rubble and gravel behind the existing liner, and replacing the liner with rock bolted shotcrete directly to the exposed siltstone bedrock.
Existing portals will be raised approximately 2.5 feet to achieve vertical clearance.
RequireS specialized work for the historic portal stone masonry, which will be removed and replaced on a new portal wall structure at a higher elevation.

34. Constructability Review Agenda GOAL: What is the highway closure duration?
Equipment
Dimensions
Location
What equipment will be required to raise the portals, excavate, etc., will it fit in the tunnel
Methods
Contingency plans for unknowns
Roadway undercutting
What protection / shoring methods will be required for the portals?
Lowering the tunnel floor and roadway:
Historic Stone Portal Removal and Reconstruction
Specialty work required to maintain material integrity during removal and reconstruction
Timber Lining Demolition
Shotcrete Lining Demolition
Materials
Concrete
Masonry materials
Historic Stone Portal Underpinning
Staging
Raising Portals
Re-Lining
Is it feasible to lower the tunnel floor, construct temporary ties into existing roadway, and stage approach roadway construction with single lane closures?
Is there any methodology to keep the highway partially open?
Durations
Existing lining removal
Roadway lowering
Rising portals: reconstruction verses lifting
Full closure versus partials

35. Tunnel Profile