Post on 26-Jun-2020
transcript
20.09.2016
Floating bridgeE39 Bjørnafjorden
Øyvind NedrebøDesign Manager
Ferjefri E39 – Teknologi for morgendagens samfunn
1
Floating Bridge, E39 Bjørnafjorden
20.09.2016
Improved design - Ship channel moved south: - Only one pylon required- Pylon on land, safe from ship collision
• Ship channel centre
• Two pylons on floating pontoons
Previously:
Ferjefri E39 – Teknologi for morgendagens samfunn
2
Floating Bridge, E39 Bjørnafjorden
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Status May 2016; Conceptual design developed for:
• Curved bridge. Bridge supported at each end, similar to the existing floating bridges in Norway,Bergsøysundet bru (1992) and Nordhordlandsbrua (1994)
• Straight bridge. Bridge supported each end,and additionally through pre-tensioned mooring lines
Curved bridge: Straight bridge:
3
Curved Bridge:
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
• Length (overall): 4659 m
• Number of pontoons: 19
• Steel: 119 000 T
• Concrete: 146 000 m3
• Steel cables (cable-stayed bridge ): 1900 T
4
Curved Bridge, Ship Channel: Cable-Stay Part, Space: 45 m x 400 m
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Source: bruer.no
Comparison Sotrabrua:- Ship channel: 49 m x 415 m
- Main ship route to Bergen from south
5
Curved Bridge. Box Girder
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Transverse beams spacing: 49,25 m
Double box girder connected through transverse box beams
6
Curved Bridge Abutment at North End ( “Flua”, -40 m)
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Bridge girder connection
7
Concrete Gravity Base (GBS) StructureSolid ballast placed in insidecompartments
Curved Bridge Abutment at South End
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
8
Curved Bridge. Pontoons
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
9
Side Anchored Bridge
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
• Length (overall): 4506 m
• Number of pontoons: 18
• Steel: 80 100 T
• Concrete: 130 000 m3
• Cables (cable-stayed bridge): 1050 T
• Mooring lines: 24 10
Side Anchored Bridge. Bridge Girder
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
11
1. Introduction
2. Bridge Anchoring. Conditions at Site
3. Bridge Construction
4. Ship Collision
5. Pontoon Optimisation
Floating Bridge, E39 Bjørnafjorden
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
12
Acoustic survey, March-April 2016
Bjørnafjorden Seabed Mapping
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Seabed: 0.5 m resolution
Detailed depth mappingusing ROV (multibeamechosounder)
Detailed image of theseabed and the depthvariability
13
Subsea Slides, Soft Clay
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Depth data (xyz) clearly reveal manyhistorical slide scars and debris lobes
14
Side Anchored Bridge. Reveal Feasible Anchor Locations
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
WE
Slope stability: Portion of slope that fails
15
Bathymetry map. Bridge lines West (W) and East (E). Bridge tower marked by yellow star
-550 m
-50 m
Side anchored bridge. Preliminary Anchor Locations
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Shown left:Suggested anchor locations (2016)(NGI)
Analysis model
W
16
Remaining work to confirm preferredanchor locations to be continued in next design phase (2017)
An iterative procedure which alsoinvolves global dynamic analyses ofmoored bridge system
1. Introduction
2. Bridge Anchoring. Conditions at Site
3. Bridge Construction
4. Ship Collision
5. Pontoon Optimisation
Floating Bridge, E39 Bjørnafjorden
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
17
Construction. Part 1: Cable-stayed Bridge
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Side span assembly:
Similar to Höga Kusten bridge (Sweden)
Crane vessel lift bridge girderelements onto tempory columnsupports
18
Construction. Part 1: Cable-stayed Bridge
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Ship channel span assembly
Bridge girder elements (20 m) liftedfrom barge using strand jacks
Similar to 3rd Bosphorous bridge, Turkey
19
Construction. Part 2: Pontoons and Abutment at Flua
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
In dry-dock and/or on barge (pontoon)
20
Simple installation ofabutment at Flua (-40 m):
Construction. Part 3: Floating Bridge Assembly
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Site assumed: Eikelandsfjorden, Fusa:
21
Construction. Part 3: Floating Bridge Assembly
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
The elevated south end (interfacing high bridge) requires crane for assembly. Construction similar to Sundsvall bridge (Sweden)
22
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Construction. Part 4: Bridge Towing Operation
Total required towing capacity: 1300 T(Storm condition, holding criteria according to Rules)
Selected: 14 vessels each 125 T pull capacityTowing speed 1.0-1.5 knots
23
Troll A GBSNordhordlandsbrua
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Construction. Part 5: Bridge Installation
Weater criteria:• Wind: 10 m/s• Wave: 0.5 m
(significant wave height)
Weather window required:• Planned duration: 48 hrs• Contingency: 48 hrs• Total: 96 hrs
Pre-installed abutment and bridge segment at north end (“Flua”)
24
Nordhordlandsbrua
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Construction. Part 5: Bridge Installation
1. Winches located on cable stayed bridge and bridge element at north end.
2. Winches pull the bridge gently towardsbridge ends. Vessels assist in holding as needed.
3. Prior to connection a guide system at each end is used
25
1. Introduction
2. Bridge Anchoring. Conditions at Site
3. Bridge Construction
4. Ship Collision
5. Pontoon Optimisation
Floating Bridge, E39 Bjørnafjorden
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
26
Part A: Relevant Collision Energy
20.09.2016
Automatic Identification System (AIS): Mandatory system used to avoid ship collisions.
Ship data such as ship registration number, position, speed, heading, etc. are exchangedthrough the VHF channel.
Collision risk analyses
Simulate one million year ofship traffic based on AIS recorded traffic data from the area
Ferjefri E39 – Teknologi for morgendagens samfunn
Failure modes considered:
1. Rudder failure
2. Propulsion failure
3. Rudder and propulsion failure
4. Human error
27
Part A: Determine Collision Energy for Design
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Ship channel
28
100 MJ
Pontoon collision
Girder collision
Part B: Ship impact. Structural resistance
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Cruise ship:• Mass: 24 344 T• Length 195.8 m• Width: 22.5 m
29
100 MJ 150 MJ 200 MJ
250 MJ 300 MJ
Part B: Ship impact. Structural resistance
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Wall thickness 110 cm
30
Maritime Safety. Collaboration NCA
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Objective:
• Establish representative input for the ship collision risk analyses
• Develop rule proposal for future traffic regulations in Bjørnafjorden
NCA: • Agency of the Norwegian
Ministry of Transport and Communications
• Responsible for services related to maritime safety
NCA pilots to run navigation simulator: Curved floating bridge modelled and imported into data base, ref.:«Den Virtuelle Sjøveien»,http://dvs.hials.no/
NTNU - Senter for simulering og visualisering
31
VTS
1. Introduction
2. Bridge Anchoring. Conditions at Site
3. Bridge Construction
4. Ship Collision
5. Pontoon Optimisation
Floating Bridge, E39 Bjørnafjorden
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
32
Pontoon Optimisation (case: Curved Bridge)
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Each pontoon shall:• Carry superstructure = 6000 T• Carry self-weight (concrete) = 12000 T • Resist large ship impact Thick wall• Have displacement adequate for ship impact
Other criteria applicable:
Motions and deflections Load condition Limit
Vertical deflection70% of characteristic
traffic load
1.0 m
Rotation about longitudinal axisdue to traffic
1.0 deg
Rotation about longitudinal axisdue to environmental loads
1 year storm
1.5 deg
Vertical acceleration 0.5 m/s2
Horizontal acceleration 0.5 m/s2
33
Wind Waves
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Fetch distances, NW: 19.0 km, E: 21.5 km
34
Hs, significant wave height (ref. Wikipedia):
The mean wave height (trough to crest) of the highest third of the waves
Tp, wave period
Ocean Waves (Swell)
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
35
Wave Load Spectrum used
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
36
Pontoon Optimisation. Part 1: Heave Response
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Flange
WestNorth
1
4
2
5
3
6
37
Pontoon Optimisation. Part 2: Sway/Surge Pendulum Effect
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Flange
WestNorth
1
4
2
5
3
6
Ongoing work - Objective:Improve pontoon geometry to limit the amount of additionalsteel required for the south elevated part of the bridge girder
38
Review and Verification
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
39
Floating Bridge, E39 Bjørnafjorden
20.09.2016 Ferjefri E39 – Teknologi for morgendagens samfunn
Takk for oppmerksomheten!40