1. Foundation
Foundation is required to support the
bridge towers, portal frames or piers. Usual foundation methods such as
H-pile, pipe-pile, borepile or precast concrete pile can be used for
such purpose.
2. Bridge Tower
This is the vertical supporting
structure only for cable suspension or cable-stayed bridges. The tower
is usually construction in high-strength concrete using in-situ method.
Mechanical climb form is most efficient for casting the bridge tower. In
some cases, the tower can be constructed in a structural frame type.
3. Pier
Pier is the vertical supporting
structure for usual spanned bridges. Pier is more suitable for bridge
with maximum width of deck up to about 8m (2 traffic lanes). Usually
bridge pier is constructed using in-situ method with large panel
formwork.
4. Portal frame
A portal usually consists on two piers
on each side with cross beam in between to support the deck. In this
case the width of deck can be up to 20m (6 traffic lanes). In some
situations the height of a portal frame can be up to 50m from ground.
Climb form can be used in this high headroom cases. The erection of a
complicated falsework system to support the portal construction is
usually involved.
5. Bridge deck
Bridge deck is the horizontal part of a bridge that support pedestrian or traffic activities.
6. Bridge anchor
Bridge anchor is required only for
suspension or cable-stay bridges to resist the pull from the suspension
cable or counter-span of the bridge. Bridge anchor can be of gravity
type using great mass for the counter-balancing, or using ground anchors
for the same purpose.
7. Suspension cable
Suspension cable is applicable for
suspension and cable-stayed bridges for the hanging, support or
counter-balancing of the bridge deck.
Different methods to form the deck of bridges
- Balanced cantilever method
- Construct in-situ
- Construct using precast beam
- Construct using precast girder section and erected by a launching machine (viaduct)
- Construct using incremental launching method
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