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DevilDevils Slide Tunnelss Slide Tunnels
The 20th ICTPA Annual MeetingThe 20th ICTPA Annual Meeting
Creating New Era for TransportationCreating New Era for
Transportation
May 26 May 26 -- 28 , 200728 , 2007
Yung-Nien (Nien) Wang, HNTB Corporation
Along Route 1 in San Mateo County, from Half Moon Bay Airport to
Linda
Mar Blvd.
Project Location
ProjectLocation
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Project Site
NORTH PORTAL
SOUTH PORTAL
Double-bore, 4000 feet each in length, 30 feet in diameter
Tunnels will cut through San Pedro Mountain
Rejoins Route 1, north of Devils Slide
Devils Slide Potential Problem
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BEFOREBEFORE AFTER
March 16, 1995 June 30, 1995
Devils Slide Restoration - 1995
CALTRANS Blasted the Loose Rocks
April 2, 2006 - Road Closed again
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Devil`s Slide Tunnels Project Elements
Local Fault Map
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Project Plan
Core storage
2130 m in length
Tunnel Segment, North & South Portals, South Rock Cut
17 borings, 3 m to 350 m in length
Inclinations from vertical ranges from 0 to 90+ degrees
Helicopter Access
Geological Investigation Program
California Red-Legged Frog
Frog Pond Peregrine Falcon
Aesthetics Portal features Retaining wall OMC site and disposal
area Air quality
Natural Environment California red-legged frog Peregrine
falcon
Environmental Issues
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Portal Alternatives Ballot
Segmental cast-in place box girder bridge type
Curved alignment
No falsework required
Keeping out of environmentally sensitive area
Bridge width 7800 mm
Traffic lane width 2400 mm
Bridge length 300 m SB, 275 m NB
Devils Slide Bridge
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Looking west, toward the North Portal area
Minimal excavation
Located in area of existing small slide masses
Requires additional support
Tunnel portal is skewed relative to the existing ridge
North Portal
NORTH PORTAL
North Portal Remove Vegetation
NORTH PORTAL
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North Portal- Side View
North Portal Close up View
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North Portal Design & Textures
South Bound North Bound
Tunnel Typical Cross Section
Traffic lane widths 3600 mm
Shoulders 2,400 mm and 600 mm wide
Sidewalk 1,200 mm wide (each side)
Vertical clearance envelope 4,750 mm
Cross passages -total 10
Tunnel Layout
Tunnels
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3-D Analysis
The NATM Sequence
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Sample of NATM Tunnel Construction
8 pairs of jet fans per tunnel bore = 32 fans total
Reversible type jet fans
1250mm in diameter
Each row of fans will be spaced approximately 135m
Ventilation System
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South Portal Top View
South Portal Front View
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South Portal - Overview
South Portal Design & Textures
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Early Contract Construction Overview
DISPOSAL AREA
OMC SITE
SOUTH PORTAL
Early Contract Construction
SOUTH PORTAL
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SRC Wall Texture
Proposed OMC Site
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Tunnel construction method (NATM, TBM, etc.) Hauling / disposal
Environment ( Red-Legged Frog) Traffic maintenance
Tunnel Construction Consideration
2001 2002 2006 2011
ROD
Construction
Overall Project Schedule
Final PS&E Design
Preliminary
Early Contract(June 2005 to April 2006)
South Rock Cut OMC building Area
Bridge Contract(September 2006 to December
2007)
Tunnel & OMC Building Contract(September 2006 to
December
2011) North and South Portal
structures Equipment Chambers
between Portals NATM tunnel Tunnel operation systems
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Tunnel w/ north and south portal structures Power supply
Lighting Tunnel systems OMC building Others
Low Bid Low Bid 11/14/06 (Kiewit Pacific)11/14/06 (Kiewit
Pacific)A. A. $ 272.366 Million$ 272.366 MillionB. 1,500 day x
$16,900B. 1,500 day x $16,900
Total = $ 297,716,000Total = $ 297,716,000
Second Low Bid = $ 353,204,075Second Low Bid = $ 353,204,075
Estimated Major Cost Elements
The 20The 20thth ICTPA Annual MeetingICTPA Annual Meeting
Creating New Era for TransportationCreating New Era for
Transportation
May 26 May 26 -- 28 , 200728 , 2007
Questions !!!
DevilDevils Slide Tunnelss Slide Tunnels
Yung-Nien (Nien) Wang, HNTB Corporation
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Community involvement
Stay on schedule
Keep within budget $$$
Safety
Final Product = DevilFinal Product = Devils Slide Tunnelss Slide
Tunnels
Success in Our Goal
