I am working on studying the design of CK Center footbridge, The bridge is generate from the CK Center and to complete the circulation, and it may have certain feng shui principle as CK Center itself. I am finding another bridge complete by Cesar Pelli to find out if there is any common technique normally use by him.
Example – Foot bridge between Petrona Towers by Cesar Pelli
By similar elements/ layout
By material use.
Beside I also try make comparison with other footbridge.
By similar material – steel
By similar condition:
– long span
– vehicle transportation beside
Example – Japan Bridge
Research Part 1
Part 1: General Information of Cladding System
A: Introduction of Cladding System
Type of Cladding:
- Precast Concrete
- Curtain Wall
- Precast Concrete
Precast concrete is better than other materials for cladding because:
- its good strength-to-weight ratio
- its mobility
- its fire performance
Precast concrete is better than in situ concrete because:
- Speed of erection
- Freedom from shuttering support on site and
- Better quality control.
The precast concrete is cast on the moulds, which and be standardization or special-made. The standardization can :
- Reduce the producing and erection costs
- Shorten the erection time
- The time for detailing.
Size of Panels
The size of the unit is affected by:
- Ease of manufacture
- Method of transportation
- Weight of lifting.
Method of Joints
- Open-drained joints
- Gasket joints
- Surface cast direct fro the mould, eg. Smooth centre, board- marked concrete, grooved or serrated, including reconstructed stone finishes;
- finishes in which the cement surface is removed to expose the aggregate in the concrete;
- applied finishes, such as tiles, stone facings and bricks;
- surface textured by tamping or shaping
The metal cladding can be categorized in two types:
- Form metal
- Sheet Metal Panel
Forming of sheet metal can be carried out in four different ways:
- brake pressing
- deep drawing
Profile metal cladding and roof decking
According to Steel Construction Institute, cladding is the envelope of the building which normally carries no loading beyond its own weight plus the loads imposed by snow, wind and during maintenance. It is the term used when the steel sheet is exposed to the elements.
Profiled steel and aluminum sheets are available in :
- Symmetrical trapezoidal
- asymmetrical trapezoidal
Method of manufacture:
- For aluminum, it has its own built-in protective surface coating of aluminum oxide, which form immediately on exposure to the atmosphere.
Method of Joints
- Nut and bolt
There are four types of sheet metal and composite panel system:
- rolled flat sheet panels mounted onto a supporting framework
- box-type panels(including proprietary panels), usually with foamed cores
- laminated panels
- rain screen panel
Composite Metal panels
Composite construction is the bonding together of layers of materials to form a rigid structure due to their different thermal and structural performance.
Some composite panels, particularly those with a foamed insulation core, failed in the past because of delamination of the outer skin from the insulation to which they were bounded.
To prevent delamination:
- Use light colors on the outer ski to reduce the heat gain on the skin.
- The size of the panel should be taken into consideration. Large panels will deflect more than small one.
- Fixings in the centre of panels should be avoided.
- The adhesive and type of insulation core should be selected to take account of stresses set up by thermal movement
- If the inner skin has a higher coefficient of expansion than the outer, then the effect of thermal movement will be reduced
- electrostatic powder coating;
- thin premium paint coatings;
- vitreous enameling
- stainless steel
- Curtain Wall
Curtain wall may be defined as being non bearing wall, usually suspended in front of a structural frame, their own deadweight and wind loadings being transferred to the structural frame through anchorage points. Usually they consist of a rectangular grid of vertical or horizontal framing with in fill panels of glass or some other lightweight panel.
Four Type of Curtain Wall System:
- patent glazing;
- pressed or extruded metal box framing;
- suspended glass assemblies;
- silicone-bonded glazing
Metal Box Framing
There are two basic approaches to assembling a box framed curtain wall:
- the component parts of the system are assembled on site, with panels being offered up to a frame, also called stick system
- the panel system is bolted together, the panels themselves becoming the frame
Reference: Cladding of Buildings by Alan J. Brookes
Next Research: Cladding on Footbridge
Here is some research of the CK Center design principle, by this we can also understand the design of the bridge as a extend of the main building with the same language. And we may also know the reason of material choosing by the architect.
Here is a PDF file attached, please click the follow image to open.
Here are some images of an indoor footbridge located in Tai Koo Plaza Oxford House(indoor)
which I would like to compare with the Cheung Kong Centre Footbridge(outdoor)
in order to understand what are the differences in fitting the building services between an indoor and outdoor footbridge.
Here are my observations from my first visit.
Overall view from ground
Underneath with metal cladding
The only staircase which collect to the ground level from bridge, unlike Cheung Kong Centre with a few more nodes.
Some drainage installed on each landing
View from staircase
View from inside, the only fire escape
An overall view of the interior
This is a highly transparent bridge with trusses and bracing system, but for the installation of sprinklers, a false ceiling is needed. For better appearance the ceiling is centralized, in order to keep the transparency of bridge.
Fire shutter can be found on one side of the bridge to prevent spread of fire
Fire shutter control panel
Fire Reels are installed on both ends
Smoke detectors are installed on both ends as well
Air-conditioning and lighting are all installed on both sides of floor, which can reduce the construction on ceiling. Power supply is installed in the slab.
Water drainage on the edge of bridge with perforated metal covering on top
With water , sprinkler and drencher inlet.
The plant probably is not only for the bridge but the whole building.