Bridge and Railroad Engineering Vocabulary

Vocabulary flashcards covering bridge engineering components, railroad track infrastructure, and structural terminology from the lecture notes.

Track

A set of rails or plates and their supports on which may be rolled a body or structure provided with wheels or rollers.

Transverse

Extending across. Crosswise direction.

Trestle

A bridge structure composed of bents or towers and supporting stringers or girders forming the floor system.

Trestle Bridge

A bridge composed of bents or towers carrying the deck. May be of either timber or metal.

Truss Bridge

A bridge made up of truss spans.

Truss Pin

A pin used at the panel point of a truss to connect the several intersecting members.

Upper Chord

The upper member of a truss, usually resisting compression. Also known as a Top Chord.

Vertical

Upright, plumb, perpendicular to the horizon. Also an upright member in a truss.

Vertical Bracing

Wind bracing lying in a vertical plane, such as sway bracing.

Vertical Lift Bridge

A bridge having a span that hoists vertically.

Wall

A structure or slab of small thickness, built in a vertical or nearly vertical plane.

Wall Plate

A steel plate laid on a masonry or a concrete wall to carry the end of a beam and to distribute its load.

Web

The portion of a truss or girder between and connecting the flanges, its function being principally to resist shear.

Web Plate

The plate forming the web of a girder.

Web Stiffener

An angle riveted to the web of a beam to distribute a load or to prevent buckling.

Weep-hole

A hole in a wall for draining the water that tends to accumulate at the back.

Wind Bracing

Bracing which takes up the stresses induced by the wind.

Wing Wall

One of the side walls of an abutment extending outward from the head wall in order to hold back the slope of an embankment.

X-Bracing

Any system of bracing in which the diagonals intersect.

Y

An arrangement of railroad tracks, resembling the letter Y, which is used for turning trains around. Sometimes spelled "Wye."

Abutment

A structure sustaining one end of a bridge span and supporting the embankment. Also that part of a pier from which an arch springs.

Anchor bolt

A round steel bolt embedded in concrete or masonry to hold down machinery, castings, shoes, spans, or engine beds.

Angle iron

A rolled piece of steel having a cross section shaped into a right angle.

Apex

The intersection of a web member with a chord or flange; also called a panel point.

Approach

The construction leading to the end of a bridge.

Ballast

Gravel, broken stone, or other road material put between ties of a railroad to prevent slipping and give solidity.

Base plate

The foundation plate of metal on which a heavy piece of machinery or the end of the bridge rests.

Bay

The portion of a trestle between two columns.

Beam

A member whose principle function is to carry a transverse load.

Bearing

The shoes for a span, or the support for a beam, pins, bolt, or rivet.

Bearing plate

A plate which receives the bearing from a pin or a plate that bears on another plate.

Bearing point

The point of support for a load or a place where concentrated pressure is applied.

Bent

A supporting frame consisting of posts or piles with bracing, caps, and sills.

Bottom Chord

The lower member of a truss, usually resisting tension.

Box girder

A type of girder having two webs forming a box-like section made of plates and angles riveted together.

Cap

The top of a column.

Chord

The portion of a truss whose main function is to resist bending on the span.

Chord splice

A splice made in the chord of a truss.

Chord stringer

A chord length subjected to bending as well as direct stress.

Column

A pillar or strut. A long member which resists compression.

Column foot

The base of a column.

Combination Bridge

A bridge constructed of timbers and steel or iron.

Concrete girder

A girder built of concrete usually reinforced with steel.

Cover plate

A plate fastened on the flanges of a girder for additional cross-section; a top or bottom plate of a chord member.

Cross beam

A beam which runs transversely to the center line of a structure.

Deck

The flooring of a bridge.

Deck Bridge

A bridge in which passing loads are carried directly to the upper chords or upper portions of the posts.

Deck girder

One of the main girders of a deck bridge.

Deflection

A lateral motion, a motion at right angles to the length of the piece.

Diaphragm

A thin plate or partition across a bridge member to stiffen it.

Efflorescence

A powder-like incrustation formed on bodies such as concrete or metals.

End post

The post at the end of a truss.

Expansion bearing

A support at the end of a span providing for expansion and contraction of the structure.

Expansion joint

A joint in which movement for expansion and contraction is allowed.

Filler plate

A plate used to fill open spaces under members or parts.

Fixed bridge

A bridge that does not move except for expansion and retraction.

Fixed end

The anchored end of a girder or strut firmly connected to prevent all motion in the vicinity of the end.

Flange

One of the principle longitudinal members of a girder which resist tension or compression.

Floor

That part of a bridge which directly receives the travel.

Floor-beam

A transverse beam placed at the panel points of a span to support stringers which carry the floor.

Fracture Critical Bridge

A steel bridge with members in tension whose failure would probably cause collapse or functional failure.

Gauge

The distance between the inside faces of the heads of the rails in a track.

Girder

A beam or compound structure acting as a beam carrying principally transverse loads.

Girder Bridge

A bridge composed of plate or lattice girders.

Grade

The degree of inclination from the horizontal, usually expressed as a percentage.

Grade crossing

A crossing where both roads or tracks are at the same elevation.

Gradient

The rate of grade, measured by rise or fall in $100\,\text{feet}$, generally expressed as a percentage.

Guide rail

An additional rail placed inside of a regular rail to prevent trains or hi-rail vehicles from leaving the track.

Gusset

An angular piece of iron or steel fastened to members to give strength and stiffness.

Gusset plate

A large connecting plate used at panel points to join chord and web members.

Half-through Girder Span

A span where the deck is between upper and lower chords and lacks overhead bracing.

Hanger

A hip-vertical or suspender of a truss or a tension member supporting a floor system.

Highway Bridge

A bridge that carries highway traffic only.

Honey-comb

A condition occurring in concrete or castings featuring cells like those of a bee's honeycomb.

Horizontal Bracing

Bracing lying in a horizontal plane.

I-Beam

A rolled structural shape with a cross-section resembling the letter "I."

I-Beam Girder

A girder composed of an I-Beam.

Indirect Stress

A stress induced by another stress.

Inflection

A change of curvature from concavity to convexity, or vice versa.

Intermediate Girder

Any girder between the two outside girders.

Jack Stringer

Also known as an Outside Stringer; a stringer placed outside the line of main stringers.

Joint

The place or part in which two things or portions of one thing are joined or united.

Knee Brace

A short diagonal brace used to connect a batter brace or vertical post to an overhead strut.

Laminated

Having plates or scales; scaly.

Lap Joint

A joint in which the pieces extend over each other; also called an Overlapping Joint.

Lateral Bracing

A system of members forming the web of a horizontal truss connecting homologous chords of opposite trusses.

Lateral System

Tension and compression members forming a horizontal truss web to transmit wind pressure and prevent vibration.

Lateral torsional buckling

An occurrence where an applied load causes both lateral displacement and twisting of a member.

Latticed Girder

A riveted girder with upper and lower flanges connected by latticing, diagonal bars, or angles.

Lift Span

A bridge span that is raised to allow passage for vessels.

Load

The weight carried by a structure or part thereof, including its own weight.

Main Member

A principal part of a truss or floor system; also known as a Primary Member.

Map-cracking

Closely spaced but irregular cracks on the surface of concrete.

Mid-span

The center of a span.

Movable Span

Any bridge span that may be moved to allow vessels to pass through or under it.

Overhead Bracing

The upper lateral or vertical sway bracing in through bridges.

Pack rust

Corrosion in joints where $1\,\text{inch}$ of rust equals approximately $\frac{1}{8}\,\text{inch}$ section loss.

Panel

The portion of a truss between adjacent panel-points in the same chord.

Panel-point

The point where the axis of a principal web member intersects the axis of a truss chord.

Pier

A structure, usually masonry, transmitting loads from the superstructure to the foundation.