PowerPointPrsentation

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Replacing Stay-Cables of the Rhine River
Crossing without Traffic Interruption
Rheinbrücke Düsseldorf Flehe, Autobahn
46 Built 1975 1979
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The Bridge Structure
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Germany
Location
Düsseldorf
Neuss

• South of Düsseldorf, state capital of North
  Rhine-Westphalia
• Carries the German Autobahn A46 across the Rhine
  river
• Daily traffic volume 75,000 cars
• Important link between Ruhr River region and the
  Netherlands

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Elevation
Pylon Height 145 m
Material interfaceconcrete to steel placed into
pylon section

Cable supported steel bridge (main span) Length
368 m
Prestressed concrete approach spans Length 780 m
Total length 1,165 m
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Cross Section
Main Span three cell box girder
Orthotropic bridge deck
Inspection equipment
Prestressed concrete as counterweight for gying
bachward cables
Approach Bridge
Inspection equipment
Width 42 m ? in total 6 lanes shoulders
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Pylon the most striking part of the bridge
Pylon Height 145 m
Pylon shaped like an inverted Y
Stayed-cables in the median
Bridge deck
Caisson foundation
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Staying Cables

• Main opening suspended by 96 cables
• Arranged in 7 groups at each side to form a harp
  and a fan
• Two cable planes in the median
• Each group consists of 2 x 3 6, the highest
  group of 2 x 6 12 staying cables
• Cable length varies, longest cable streches up to
  320 m
• Cable diameter 93 111 mm, up to 300 wires

Harp
Fan
320 m
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Staying Cables locked coil ropes

• Cross section of the cables (assembled as locked
  coil ropes)
• inside core of 61 round wires
• outside 4 6 layers of Z-shaped wires twisted
  around (selfsealing the surface)
• Up to 325 single wires per cable

• Outermost layers are hot galvanized
• Red lead (stranding) used as sliding agent(tend
  to squeeze out)
• Corrosion protection by a polyurethane-zinc-chrom
  atic agent(weak bond properties)

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Cable Damage
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Cable damage
Sommer 2002
Alte Kabelhaube entfernen
Highest cable group R100 ? 7 unconstrained
broken wires hanging down
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Cable damage
Immediate investigation wire fractures due to
stress-induced corrosion cracking (primary
cause) In general exterior corrosion protection
layer in bad condition
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Cable damage inspection report 2003

• In total 88 broken wires in 77 cables within the
  cable groupsR100 R700(data sheets from visual
  and magnet-inductive tests)
• 24 broken wires in cable group R100 7 new
  fractures
• Moisture underneath the corrosion protection layer

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Repair and Reconditioning
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Repair and reconditioning

• 1) Replacement of stayed-cables
• Several repair methods were discussed
• Most damaged cables had to be replaced
• 9 out of 96 cables (most damaged)
• Open fractures within the exterior wires
• Numerous broken wires inside the cable
• Minor damaged cables neednt to be replaced
  (redundancy)
• Due to high traffic use, replacement of cables
  without interruption of traffic flow, avoiding
  major delays, or restrictions
• Keeping the entire bridge under full
  service(requiring skills and experiences of
  engineers and craftsmen each step deliberately
  pondered)

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Repair and reconditioning
Cables to be replaced

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Repair and reconditioning

• 2 ) Reconditioning of corrosion protection
• New cables alle wires are hot dipped the 2
  outermost layers were galvanized using GALFAN dip
  (according to current standards)
• GALFAN a very corrosion-resistant zinc layer
  with up to 5 aluminum content
• All cables got new corrosion protection
• 4 layers with technical approval
• Applying the corrosions layers under sheltered
  condition

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Replacement 1) Removal of broken cables
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Anchoring positions of cables
Approach span
Steel-box girder
Bridge deck
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Release from tension
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Threading out and lowering the cables
still fixed at the pylon
held by moveable chairs rolling on top of other
cables like scooters
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Cutting into Handy pieces
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Replacement 2) Assembly of new cables(reverse
order of cable removing )
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Supplying the new cables
Length 320 m Weight 25 t (80 kg/m)
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Pulling up the cables by winches, threading in,
and anchoring at the pylon
Seilkopf
incorporation of new cables in reverse order as
they were removed
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Threading in the cables and assembling the upper
anchorage position at the pylon
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Threading in and assembling the lower anchoring
position at the bridge deck
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Stressing the cables
Prestressing force 4000 KN
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Finally fixed anchorags at the pylon
replacement procedure has been repeated 9 times
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Replacement 3) Corrosion protection after cables
were applied
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Suspended scaffolding sheltering from wind and
rain for quality reasons of corrosion protectiv
work
first element
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Carriages devices
held by moveable chairs rolling on top other
cables like scooters
Carriages
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Sweeping the cable surfaces
light brushing to remove rost and old coatings
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Applying the corrosion protection layers
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Thank you for your attention