Coastal Highway E39 – technological solutions

Coastal Highway E39
National start-up conference, Stavanger 25 March 2011
Coastal Highway E39 –
technological solutions
Lidvard Skorpa
Norwegian Public Roads Administration,
Western Region
Why a dedicated technology project
for fjord crossings ?
Characteristic features of ”extreme” fjord crossings:
– Width: 2-6 km
– Depth: 300-600 m
– Varying degree of exposure to natural loads
(waves, current, wind)
– Considerable amount of shipping
Changing technology
New technology has given us modern ferries,
but we cannot stop at that!
Development of technology for Norwegian
fjord crossings, status as of spring 2009
Undersea rock tunnels – continuous development
– current records are 7888 m length, 287 m depth.
Fixed bridges – suspension bridge with a planned main span of
1310 m.
Pontoon bridges – little activity since the Nordhordland bridge
was opened in 1994.
Floating tunnels – little activity since the Høgsfjord project was
shelved in 2000.
Immersed tunnels – the Bjørvika tunnel under construction.
Development of offshore structures, fixed and floating, at
increasing depths.
If the remaining ground breaking fjord crossings
are to be solved, we will need to:
– Develop new technology
– Acquire new competencies
Dedicated technology development project
essential
This will require long-term focused work
efforts
Feasibility study
– crossing the Sognefjord
Lavik
Oppedal
E39
”Extreme” fjord crossing:
Width: approx. 3.7 km
Depth: over 1250 m,
sudden deep waters
approx. 1500 m to rock
Screened from ocean waves
- Navigation channel required for
large cruise ships
Objectives for the feasibility study
Provide an answer, at concept level, to whether it will be
technically possible to build a fixed link across the Sognefjord.
Point out the most realistic solutions based on expected
technological developments.
Part of a wider project concerned with the development of fjord
crossing technology in connection with a Coastal Highway E39.
Carve out a position ahead of potential specific projects with
respect to the development of appropriate technology.
Framework for the feasibility study
Launched in the spring of 2009 on the initiative of the
regional public roads director, Western Region.
Project team formed, made up of experts from the
Norwegian Public Roads Administration as well as external
consultants.
Established as a major project under the Project Section,
Western Region in 2010.
Focus on technical expertise and previous experience of
relevant major projects (bridges and offshore).
Fixed link options:
The Sognefjord
• Suspension bridge
• Pontoon bridge
w. combinations
• Floating tunnel
(Rock tunnel not an option
here)
Fjord crossings, KVU E39 Aksdal-Bergen
Fjord crossings,
CCS E39 SkeiÅlesund
Undersea rock tunnels for road traffic:
- The Bømlafjord tunnel:
length 7888 m
- The Eiksund tunnel:
depth 287 m
- The Rogaland fixed link:
length approx. 25 km (dual bore), depth
approx. 380 m
- The Sognefjord:
depth over 1500 m
Hareid and Festøya fixed links
Depths of more than 600 m, length 20-25 km, dual bore
Longest suspension bridge main
spans:
The Hardanger bridge
The Great Belt
The Akashi-Kaikyo Bridge
Strait of Messina Bridge
The Sognefjord
1310 m
1624 m
1991 m
3300 m
3700 m
Development of new technology for
no-ferry fjord crossings
Suspension bridge across the
Hardangerfjord
The Sognefjord
Suspension bridge
solution:
• Main span almost three
times as long as the
Hardanger bridge, and
almost twice as long as
the current longest span
in the world!
• Is it possible to reduce
the span by building the
bridge tower foundations
on floating pontoons?
Facts about the Hardanger Bridge
Length of main span: 1310 m
Tower height: 201.5 m
Bridge beam: 18.3m x 3.25 m
Akashi-Kaikyo Bridge
The world’s longest suspension bridge span
Bridge across the Strait of Messina and
Golden Gate
Challenges for long suspension bridges
New ”Norwegian” suspension bridge concept for
long spans (over approx. 1500 m):
Requires slim-line construction
Avoid aerodynamic instability by means of
– cable configuration
– split lanes
Suspension bridge across the Sognefjord
Suspension bridge across the Sognefjord
Alternative involving pontoon
foundations
Suspension bridge across the Korsfjord
Long pontoon bridges:
The Nordhordland bridge: (floating section)
1246 m
(separate pontoons, end anchors)
Evergreen Point Floating Bridge:
2300 m
(continuous pontoon structure, side anchors)
William R. Bennet Bridge:
The Sognefjord:
approx. 700 m
3700 m
Evergreen Point Floating Bridge
Lake Washington, USA
Limited amount of shipping on the lake.
Development of new technology for no-ferry
fjord crossings
The Nordhordland bridge
End anchors, length of floating section 1246 m
The Sognefjord
Pontoon bridge
solution:
• Difficult to find
appropriate foundations for
end anchors due to sudden
extremely deep waters.
• Floating section will be
approx. three times as long.
Pontoon bridge options:
Navigation channel:
– Mid-fjord or close to shore
Anchoring the pontoon bridge section:
– End anchors or side anchors
Traffic solution for crossing the navigation
channel:
– Fixed or moveable bridge above the navigation channel,
or floating tunnel underneath the navigation channel
Curved designs with end anchors require a widened
cross section to ensure the appropriate rigidity.
Pontoon bridge across the Sognefjord
(mid-fjord navigation channel)
Pontoon bridge across the Sognefjord
(mid-fjord navigation channel)
Some – of many - pontoon bridge
design options assessed
Combined with a bascule
bridge across the mid-fjord
navigation channel
Combined with a floating
tunnel underneath the midfjord navigation channel
Pontoon bridge across the Sognefjord
(mid-fjord navigation channel)
Pontoon bridge across the Sognefjord
(navigation channel close to shore)
Pontoon bridge across the Sognefjord
(navigation channel close to shore)
Pontoon bridge combined with floating
tunnel close to shore:
Pontoon bridge with end anchors,
the Storfjord
Floating tunnel with side anchors,
across the Bjørnafjord
Submerged floating tunnel:
(None built so far)
–
–
–
–
The Høgsfjord bridge:
Strait of Messina:
Prototype China:
The Sognefjord:
1400 m
approx. 5 km
100 m
3700 m
Development of new technology for no-ferry
fjord crossings
Planned floating tunnel across the Høgsfjord
Approved as preferred link design (1998), but not built
The Sognefjord
floating tunnel solution:
• Separate escape tunnel required.
• Anchor problems due to extreme
depth!
• Possible solution involving
pontoons on the surface.
Floating tunnels:
Absorption of vertical forces:
– anchored to pontoons on the surface
– anchored to the sea bed by cable stays
Absorption of horizontal forces:
– end anchors, curved shape
– vertical or diagonal cable stays
Floating tunnel made from two curved tubes
anchored to surface pontoons.
Parallel twin tubes
(one-way traffic, escape route)
Floating tunnel across the Sognefjord
Floating tunnel across the Sognefjord
Floating tunnel with diagonal cable
stay anchorage:
Floating tunnel with diagonal
cable stay anchorage:
The fjord crossing project
The feasibility study for crossing the
Sognefjord:
Idea phase completed, we have embarked on the
documentation phase.
We have reason to believe it would be technically feasible
to cross the Sognefjord by means of a suspension bridge,
a pontoon bridge or a floating tunnel.
We have acquired knowledge for other fjord crossings.
Conclusion: there is a basis on which to continue our
work to develop new technology for crossing fjords
The fjord crossing project
Specific fjord crossings investigated in
connection with the Concept Choice
Study:
It appears feasible to build fixed links across all the fjords
assessed
Not all crossing options are suitable for all locations
There is significant uncertainty associated with the
estimated costs
More detailed pilot projects must be implemented
before a final choice of crossing solution can be made
Pure fantasy …. or ??
- Progressing from idea to
implementation requires long-term
focused work efforts!
Who would have
believed in the 1960s
that it would be
possible for
structures to be
standing in the
middle of the North
Sea?
The Ekofisk Tank:
70 m depth (1973)
The Troll platform:
303 m depth
(1995)
Buoyant platforms
(TLP) moored at
depths of more
than 1500 m
The Millau viaduct (mast summit at 324 m)
270 m from valley floor to roadway!
Further work
Completing the feasibility study
Document the feasibility of the various solutions
emerging from the idea phase
Health and safety clarifications
(construction phase, road users, shipping,
structural collapse etc.)
Other factors such as costs, environmental
impact, etc.
The fjord crossing project
Fjord crossings which were previously considered
”impossible” without a ferry service now appear
to be possible candidates for a fixed link in the
reasonably near future.
Progressing the project will depend on the
enthusiastic involvement and conscious effort put
in by experts as well as councillors and
politicians.
The fact that the region’s political representatives
have expressed a clear long-term objective of
securing an uninterrupted Coastal Highway E39
between Kristiansand and Trondheim, is a strong
encouragement for our future work!
- Thanks for listening!