BridgeA bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually something that is otherwise difficult or impossible to cross. There are many different designs of bridges, each serving a particular purpose and applicable to different situations.
Girder bridgeA girder bridge is a bridge that uses girders as the means of supporting its deck. The two most common types of modern steel girder bridges are plate and box. The term "girder" is often used interchangeably with "beam" in reference to bridge design. However, some authors define beam bridges slightly differently from girder bridges. A girder may be made of concrete or steel. Many shorter bridges, especially in rural areas where they may be exposed to water overtopping and corrosion, utilize concrete box girder.
GirderA girder ('gɜrdər) is a beam used in construction. It is the main horizontal support of a structure which supports smaller beams. Girders often have an I-beam cross section composed of two load-bearing flanges separated by a stabilizing web, but may also have a box shape, Z shape, or other forms. Girders are commonly used to build bridges. A girt is a vertically aligned girder placed to resist shear loads. Small steel girders are rolled into shape.
Deck (bridge)A deck is the surface of a bridge. A structural element of its superstructure, it may be constructed of concrete, steel, open grating, or wood. Sometimes the deck is covered by a railroad bed and track, asphalt concrete, or other form of pavement for ease of vehicle crossing. A concrete deck may be an integral part of the bridge structure (T-beam or double tee structure) or it may be supported with I-beams or steel girders. When a bridge deck is installed in a through truss, it is sometimes called a floor system.
Chord (music)A chord, in music, is any harmonic set of pitches/frequencies consisting of multiple notes (also called "pitches") that are heard as if sounding simultaneously. For many practical and theoretical purposes, arpeggios and other types of broken chords (in which the chord tones are not sounded simultaneously) may also be considered as chords in the right musical context. In tonal Western classical music (music with a tonic key or "home key"), the most frequently encountered chords are triads, so called because they consist of three distinct notes: the root note, and intervals of a third and a fifth above the root note.
Beam bridgeBeam bridges are the simplest structural forms for bridge spans supported by an abutment or pier at each end. No moments are transferred throughout the support, hence their structural type is known as simply supported. The simplest beam bridge could be a log (see log bridge), a wood plank, or a stone slab (see clapper bridge) laid across a stream. Bridges designed for modern infrastructure will usually be constructed of steel or reinforced concrete, or a combination of both.
Barre chordIn music, a barre chord (also spelled bar chord) is a type of chord on a guitar or other stringed instrument played by using one finger to press down multiple strings across a single fret of the fingerboard (like a bar pressing down the strings). Players often use this chording technique to play a chord that is not restricted by the tones of the guitar's open strings. For instance, if a guitar is tuned to regular concert pitch, with the open strings being E, A, D, G, B, E (from low to high), open chords must be based on one or more of these notes.
Extended chordIn music, extended chords are certain chords (built from thirds) or triads with notes extended, or added, beyond the seventh. Ninth, eleventh, and thirteenth chords are extended chords. The thirteenth is the farthest extension diatonically possible as, by that point, all seven tonal degrees are represented within the chord (the next extension, the fifteenth, is the same as the root of the chord). In practice however, extended chords do not typically use all the chord members; when it is not altered, the fifth is often omitted, as are notes between the seventh and the highest note (i.
Strength of materialsThe field of strength of materials (also called mechanics of materials) typically refers to various methods of calculating the stresses and strains in structural members, such as beams, columns, and shafts. The methods employed to predict the response of a structure under loading and its susceptibility to various failure modes takes into account the properties of the materials such as its yield strength, ultimate strength, Young's modulus, and Poisson's ratio.
Factor (chord)In music, a factor or chord factor is a member or component of a chord. These are named root, third, fifth, sixth, seventh, ninth (compound 2nd), eleventh (compound 4th), thirteenth (compound 6th), and so on, for their generic interval above the root. In harmony, the consonance and dissonance of a chord factor and a nonchord tone are distinguished, respectively. Chord factors are taken into consideration in voicing and voice leading.
