Types of bridge(theory.explanation)

Types of Bridge(Theory/Explanation)

Data Collected By:KUSHAL PATEL

CLASSIFICATION OF BRIDGES

TYPES OF BRIDGE

BEAM BRIDGE ARCH BRIDGEMOVABLE

BRIDGE/CANTILEVER BRIDGE

CABLE SUPPORTED

BRIDGESTRUSS BRIDGE

CLASSIFICATION OF BRIDGES (BEAM BRIDGES)

Beam Bridges

• Beams are made of different materials of which the most common are concrete, steel, timber or aluminum.

• Beams may be used in different parts of a structure, but in this context, as main carrying elements, they normally support the bridge deck.

Bridges with T - Beams

• For T-Beams, the beams and the deck are rigidly connected to each other in one type, while in others, the beam itself is shaped like a T.

CLASSIFICATION OF BRIDGES (ARCH BRIDGE)

ARCH BRIDGES

• The main elements of these types of bridges are respectively the arches. The arch of an arch bridge is a curved beam.

• Arch bridges take normally longer span lengths than vault bridges because the ribs are designed to resist a load combination of axial compression and bending moment.


• The type of structure termed arch includes open and closed spandrel arch bridges as well as earth filled arch bridges.

• The bridge deck can be either above, between or underneath the arches. So far as new arch bridges are concerned, the arch ribs are usually made of concrete or steel.


• An open spandrel arch bridge is usually constructed of reinforced concrete or in combination with steel.


• A closed spandrel arch rib bridge has its side walls connected to the arch ribs where the walls are usually made of reinforced concrete.

CLASSIFICATION OF BRIDGES (TRUSS BRIDGE)

• For this type of bridge the main load carrying element is the truss, and it is the truss that transfer the loads to the substructure.

• The bridge deck may be above, between or underneath the trusses. If the deck is above the trusses, it means that the deck is above the top chord of the trusses. If the deck is underneath the trusses, it means that the deck is situated at the same level as the bottom chord of the trusses. If the deck is between the trusses, this means that the deck is situated somewhere between the bottom and top chord of the trusses.

CLASSIFICATION OF BRIDGES (TRUSS BRIDGE)

CLASSIFICATION OF BRIDGES (CABLE SUPPORTED BRIDGES)

• A Cable Bridge is a bridge in which the superstructure is directly or indirectly supported by cables, and where the cables pass over or are attached to the towers.

• The Static System of a Cable Supported Bridge is dependent on how the Stiffening Structure is supported on the towers. It can be either simply supported or continuously.


Suspension Bridges

• Suspension Bridges have normally two towers on which the cables rest, and the tensile forces of the cables are transmitted to the anchoring at the extreme ends of the cables.. If there is more than one main span, a suspension bridge might have more than two towers.

• The hangers are connected to the cables at one end and to the cross beams or the stiffening structure at the other.


VIADUCT: SEPERATELY SUPPORTED SPANS


Cable Stayed Bridges

• Cable Stayed Bridges must have at least one tower, but if there are more than two main spans, two or more towers have to be provided.

• In the case of Cable Stayed Bridges, the bridge deck is carried by cables anchored to the upper part of the tower(s) at one end and to the bridge deck at the other. Normally the tensile forces of the cables are transmitted to the tower(s) with anchoring only in the bridge deck at each side of the tower. Sometimes, however, the cables can be anchored to the deck at one side of the tower and in the ground or rock at the other side.


CLASSIFICATION OF BRIDGES (MOVEVABLE BRIDGES)

• A Moveable bridge is a bridge having one or more spans capable of being raised, turned, lifted, or slid from its closed position in order to provide passage to navigable traffic.

• A Moveable Bridge is in most cases an ordinary beam/girder bridge equipped with machinery which allows the bridge to move in the desired direction.


Bascule Bridges

• A Bascule Bridge is a bridge crossing a waterway with one or two leaves which rotate from a horizontal to a near-vertical position, providing unlimited clear headway.

• The superstructure of a bascule bridge turns around a horizontal trunnion - in the vertical plane.

• The principal systems for Bascule Bridges are:

- Fixed Trunnion Bascule Bridge

- Rolling Lift Bascule Bridge

- Bascule Draw Bridge

- Double Leaf Bascule Bridge




Swing Bridges

• A Swing Bridge is a moveable bridge in which the superstructure rotates horizontally about a center pier (pivot), to permit the passage of navigable traffic.


• A Balanced Cantilever Bridge is located on top of a pier and rests on a pivot.

• The superstructure of the bridge has two leaves of the same length which can span two waterways.

• A sketch of a balanced cantilever bridge is shown below. The spans are usually, but not necessarily equal. When open, the swing spans are cantilevered from the pivot.

• When closed, the spans are supported by the pivot pier and by two rest piers (outer) or abutments.



Engineering

Types of bridge(theory.explanation)