Span (architecture)

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Span (architecture)

Span is a section between two intermediate supports, e.g. of a beam

Beam (structure)

A beam is a List of structural elements that is capable of withstanding Structural load primarily by resisting bending. The bending force induced into the material of the beam as a result of the external loads, own weight and external reactions to these loads is called a bending moment....
or a bridge

Bridge

A bridge is a structure built to span a gorge, valley, road, Rail tracks, river, body of water, or any other physical obstacle, for the purpose of providing passage over the obstacle....
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Encyclopedia

Span is a section between two intermediate supports, e.g. of a beam

Beam (structure)

Bridge

A bridge is a structure built to span a gorge, valley, road, Rail tracks, river, body of water, or any other physical obstacle, for the purpose of providing passage over the obstacle....
. A span can be made of a solid beam or of a rope. The first kind of span is used for bridges, the second one used for power line

Electric power transmission

Electric power transmission is the bulk transfer of electrical power , a process in the delivery of electricity to consumers. A power transmission grid typically connects power plants to multiple Electrical substation near a populated area....
s, overhead telecommunication lines, some type of antennas

Antenna (radio)

An 'antenna' is a transducer designed to transmitter or receive Electromagnetic radiations. In other words, antennas convert electromagnetic waves into electrical currents and vice versa....
or for aerial tramway

Aerial tramway

An aerial tramway is a type of aerial lift in which a cabin is suspended from a Wire rope and is pulled by another cable.An aerial tramway is often called a cable car or ropeway, and sometimes incorrectly referred to as a gondola lift ....
s.

The span is a significant factor in finding the strength and size of a beam as it determines the maximum bending

Bending

In engineering mechanics, bending characterizes the behavior of a structural element subjected to an external Structural load applied perpendicular to the axis of the element....
moment

Moment (physics)

In physics, the term "moment" can refer to many different concepts:*Moment of force is a synonym for torque, an important basic concept in physics, civil engineering, and mechanical engineering....
and deflection

Deflection

Deflection or deflexion may refer to:*Deflection *Deflection *Deflection *Electrostatic deflection*Deflection ...
. The maximum bending moment and deflection in the pictured beam is found using:

moment: M_max = 1/8 · q · L²

deflection: f_max = 5/48 · M_max· L² / (E · I)

From this it follows that if the span is doubled, the maximum moment (and with it the stress) will increase four times, and deflection will increase sixteen times.

For remarkable long-distance rope spans, used as power line, antenna or for aerial tramways, see List of spans

List of spans

The following is a list of remarkable spans, either used for powerline crossings of rivers, sea straits or valleys, as antenna or for aerial tramways....
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Span (architecture)

See also