What must a footbridge be able to do?
Footbridges are often situated to allow pedestrians to cross water or railways in areas where there are no nearby roads. They are also located across roads to let pedestrians cross safely without slowing traffic.
What shapes are best for bridges?
For example, bridges must be able to hold up the materials that make the bridge, as well as all of the traffic travelling across it. One of the shapes that can bear weight very well is the triangle.
How wide should a footbridge be?
The minimum inside clear width of a pedestrian bridge on a pedestrian accessible route is 8 feet. (AASHTO Guide for the Planning, Design, and Operation of Pedestrian Facilities, 2004), (Article 3.5. 3). The width required is based on the type, volume, and direction of pedestrian and/or bicycle traffic.
What is the live load for a footbridge?
Pedestrian live load — The typical pedestrian traffic live load is 85 pounds per square foot (psf). This represents an average person occupying 2 square feet of bridge deck area and is considered a reasonable, conservative service live load that is difficult to exceed with pedestrian traffic.
What makes a good bridge design?
The prototypical bridge is quite simple—two supports holding up a beam—yet the engineering problems that must be overcome even in this simple form are inherent in every bridge: the supports must be strong enough to hold the structure up, and the span between supports must be strong enough to carry the loads.
What is the strongest structure for a bridge?
Even though the truss bridge design has been around for literally centuries it is widely regarded as the strongest type of bridge.
How high is a footbridge?
For a simple footway, a minimum clear width of 2.0 m is required by the highways authorities. Railway station footbridges can be less wide. To the sides of this footway, parapets are required, which should be 1.15 m high over roads or 1.5 m high over railways, the height measured from the footway surface in both cases.
What equipment do you need to build a truss footbridge?
Fabricators who specialise in hollow section fabrication are familiar with all the types of detail needed for truss footbridges and have appropriate equipment, such as profile cutting equipment for tubulars etc.
How do you make a steel footbridge?
The simplest method of employing structural steel as the prime structural element of a footbridge is to use a pair of girders (fabricated or rolled sections), braced together for stability and acting as beams in bending, with a non-participating walkway surface on top.
What is the floor of a truss bridge made of?
The floor of a truss or Vierendeel girder footbridge will usually be of steel plate, though precast planks have been used with trusses. The lighter steel deck is now generally preferred.
What is the difference between composite and steel footbridge?
Composite construction produces a much heavier structure than an all-steel footbridge; the dead load accounts for over half of the total load in most cases. The extra weight and consequent stiffness of this form of construction has the advantage of being less responsive to dynamic excitation.