Other People Are Reading
Beam Bridge Features
A beam bridge is the simplest type of bridge construction. It consists of a solid structural beam used to span a gap or crevice. The beam is supported by piers on either side of the opening, or may even rest directly on the ground. Beam bridges typically span distances of less than 250 feet, making them a popular choice for overpasses and footbridges.
Excavation and Supports
The construction of a beam bridge starts with installing supports on either side to support the weight of the bridge. Simple bridges are set on the ground without the use of supports, but this still requires ground preparation. The edges of the opening are tested to ensure they are stable. To increase stability, shoring or underpinning techniques may be applied. It may also be necessary to backfill or excavate the soil to set the bridge at the desired elevation.
Typically, vertical piers are placed on either edge of the bridge to ensure the correct support is provided. These piers are made from masonry, concrete or steel and are often embedded in concrete to maintain a stable base.
Building the Bridge
The bridge span itself is constructed in a separate location then transported to the job site. Beam bridges are made from two steel or concrete girders connected by some type of decking material. The girders may be comprised of solid beams or built from webbed trusses to add strength. Once the bridge is complete it is lifted on to the supports using a crane, then welded to ensure a firm connection.
Beam bridges are often made of pre-stressed concrete. This allows them to withstand the combined forces acting upon them. The top of the bridge is subject to compressive strength while the bottom is stretched due to tensile strength. Of course, these forces are not visible in a beam bridge that is properly supported.
- 20 of the funniest online reviews ever
- 14 Biggest lies people tell in online dating sites
- Hilarious things Google thinks you're trying to search for