millenium dome case
TRANSCRIPT
MILLENIUM DOME,GREENWICH
INTRODUCTION
Vision of the project
Built to celebrate the arrival of new millennium in 2000
•Architect-Richard Rogers
•Structural Engineer-Buro Happold
Period of construction-1996-2000
Project cost-758 million pounds
Building Category-Exhibition and assembly
LAYOUT
Diameter-320 meters
Central height-48 m
Enclosed area-80,000 sqm
(20 acres)
Capacity-40,000 ppl
Main design challenges:
•Long span
•Lighting for the enclosed
spaces
Development of tensioned straight cables -History
•The elimination of one set of cables brings with it
the removal of cross clamps and anchorages
•Whether the load is acting downwards or upwards,
the cable is tensioned in the same direction, which
can be a great advantage if this tension is taken
by a funicular arch or ring beam
•With just one set of cable, connections between
the fabric cladding and cable can be greatly
simplified which results in easier roof installation
Simply Suspended Cables
Pre Tensioned Cable beams
Pre Tensioned Cable net
Tensioned Straight Cables-Advantages
LOAD TRANSFER
CABLE RING
CIRCUMFERENTIAL
CACLE
UPPER HANGER
LOWER
TIE
DOWN
STRINGERSCATENARY CABLE
DETAILING-MASTS
•Pyramidal base to suit space planning•Inclination (17 deg) provided on the basis of equilibrium conditions•Rubber pot bearing with a single locating joint to allow rotation
DETAILS-CLADDING MATERIAL
PTFE (polytetrafluoroethylene) coated glass fiber
•Flame resistant•Unaffected by UV light•Water proof and dirt resistant
Needed a translucent fabric roof with insulation
To achieve a light spectrum as close to daylightTo avoid condensation of air within the building
Double layered fabric roofing provided
•To provide a layer of air as insulation•To avoid risks
•The stiffening in the cables is provided by highly pretensioned cables(Each radial cable is subjected to 400 kn-2/3 of the tension capacity)
•Needed because of the long span of the radial cable-150m
•Tapering segments provided due to the reduced stiffness and excessive
deflection under rain and snow loads
•Slope increases with the span of fabric panels.
DETAILS-CABLES
DETAILS-CABLES-”WISH BONES”
Circumferential cables on the fabric roof can lead to water accumulation
Rigid members introduced to keep cablesOff the roof
CONSTRUCTION PROCESS-MAST ERECTION
CONSTRUCTION PROCESS
CONSTRUCTION PROCESS
Arrangement of lifting equipmentin the masthead
Assemble concentric rings of cables on the ground andInstall the individual radial cables between the rings at ground level
Use temporary extension cables attached to the permanent hangers, the rings were pulled up Using three separate cable jacks of each of the 12 masts.
The separate infill radial cables between the circumferential rings were than installed
Finally the cable net was post tensioned.
CONSTRUCTION PROCESS-CLADDING