Glossary
Abutment -
the outermost end supports on a bridge, which carry the load from the deck
Aluminum -
a lightweight chemical element (Al); the most abundant metallic element in the Earth's crust
Anchorage -
a secure fixing, usually made of reinforced concrete to which the cables are fastened
Aqueduct -
a bridge or channel for conveying water, usually over long distances
Arch Bridge -
a curved structure that converts the downward force of its own weight, and of any weight pressing down on top of it, into an outward force along its sides and base
Arch Dam -
a dam with an arched shape that resists the force of water pressure; requires less material than a gravity dam for the same distance
Architect -
a person who designs all kinds of structures; must also have the ability to conceptualize and communicate ideas effectively -- both in words and on paper -- to clients, engineers, government officials, and construction crews
Beam -
a rigid, usually horizontal, structural element
Beam Bridge -
a simple type of bridge, composed of horizontal beams supported by vertical posts
Bedrock -
the solid rock layer beneath sand or silt
Bend -
(v.) to curve; bending occurs when a straight material becomes curved; one side squeezes together in compression, and the other side stretches apart in tension
Bends -
(n.) see caisson disease
Brace -
(n.) a structural support; (v.) to strengthen and stiffen a structure to resist loads
Brittle -
characteristic of a material that fails without warning; brittle materials do not stretch or shorten before failing
Buckle -
to bend under compression
Buttress -
a support that transmits a force from a roof or wall to another supporting structure
Buttress Dam -
a gravity dam reinforced by structural supports
Cable -
a structural element formed from steel wire bound in strands; the suspending element in a bridge; the supporting element in some dome roofs
Cable-Stayed Bridge -
a bridge in which the roadway deck is suspended from cables anchored to one or more towers
Caisson -
a watertight, dry chamber in which people can work underwater
Caisson Disease -
an affliction developed by people moving in and out of caissons quickly; also called the bends and decompression sickness
Cantilever -
a projecting structure supported only at one end, like a shelf bracket or a diving board
Cast Iron -
a brittle alloy with high carbon content; iron that has been melted, then poured into a form and cooled; can be made into any shape desired
Civil Engineer -
an engineer who plans, designs, and supervises the construction of facilities essential to modern life
Cement -
a binding material, or glue, that helps concrete harden
Coffer -
a sunken panel in a ceiling
Cofferdam -
a temporary dam built to divert a river around a construction site so the dam can be built on dry ground
Column -
a vertical, structural element, strong in compression
Compressed-Air Chamber -
the space at the bottom of a caisson into which air is introduced under pressure to exclude water so that excavation can take place
Compression -
a pressing force that squeezes a material together
Concrete -
a mixture of water, sand, small stones, and a gray powder called cement
Construction Manager -
a person who coordinates the entire construction process -- from initial planning and foundation work through the structure's completion
Continuous Span Beam Bridge -
simple bridge made by linking one beam bridge to another; some of the longest bridges in the world are continuous span beam bridges
Core -
central region of a skyscraper; usually houses elevator and stairwell
Cut and Cover -
a method of tunnel construction that involves digging a trench, building a tunnel, and then covering it with fill
Deck -
supported roadway on a bridge
Diversion Channel -
a bypass created to divert water around a dam so that construction can take place
Dome -
a curved roof enclosing a circular space; a three-dimensional arch
Downstream Face -
the side of the dam that is not against the water
Dynamite -
a blasting explosive, based on nitroglycerin, but much safer to handle than nitroglycerin alone
Electrical Engineer -
an engineer concerned with electrical devices and systems and with the use of electrical energy
Embankment Dam -
a dam composed of a mound of earth and rock; the simplest type of gravity dam
Engineering -
a profession in which a knowledge of math and natural science is applied to develop ways to utilize the materials and forces of nature for the benefit of all human beings
Environmental Engineer -
an engineer who designs and operates systems to provide safe drinking water and to prevent and control pollution in water, in the air, and on the land
Fire-Setting -
an ancient tunneling technique in which rock is heated with fire and then doused with cold water, causing the rock to fracture
Force -
any action that tends to maintain or alter the position of a structure
Geodesic Dome -
a dome composed of short, straight pieces joined to form triangles; invented by Buckminster Fuller
Geotechnical Engineer -
an engineer who evaluates and stabilizes foundations for buildings, roads, and other structures
Gravity Dam -
a dam constructed so that its great weight resists the force of water pressure
Gunpowder -
any of several low-explosive mixtures used as a blasting agent in mining and tunneling; the first such explosive was black powder, which consists of a mixture of potassium nitrate, sulfur, and charcoal
Iron -
a chemical element (Fe); one of the cheapest and most used metals
Joint -
a device connecting two or more adjacent parts of a structure; a roller joint allows adjacent parts to move controllably past one another; a rigid joint prevents adjacent parts from moving or rotating past one another
Load -
weight distribution throughout a structure; loads caused by wind, earthquakes, and gravity, for example, affect how weight is distributed throughout a structure
Masonry -
a building material such as stone, clay, brick, or concrete
Mechanical Engineer -
an engineer who applies the principles of mechanics and energy to the design of machines and devices
Monolithic Dome -
a dome composed of a series of arches, joined together with a series of horizontal rings called parallels
Movable Bridge -
a bridge in which the deck moves to clear a navigation channel; a swing bridge has a deck that rotates around a center point; a drawbridge has a deck that can be raised and lowered; a bascule bridge deck is raised with counterweights like a drawbridge; and the deck of a lift bridge is raised vertically like a massive elevator
Nitroglycerin -
an explosive compound made from a mixture of glycerol and concentrated nitric and sulfuric acids, and an important ingredient of most forms of dynamite
Perimeter -
the distance around the outside of a shape
Pier -
a vertical supporting structure, such as a pillar
Pendentive -
a triangular shape that adapts the circular ring of a dome to fit onto a flat supporting wall
Pile -
a long, round pole of wood, concrete, or steel driven into the soil by pile drivers
Pile Driver -
a noisy machine that repeatedly drops a heavy weight on top of a pile until the pile reaches solid soil or rock or cannot be pushed down any farther
Plastic -
a synthetic material made from long chains of molecules; has the capability of being molded or shaped, usually by the application of heat and pressure
Pressure -
a force applied or distributed over an area
Reinforced Concrete -
concrete with steel bars or mesh embedded in it for increased strength in tension; in pre-tensioned concrete, the embedded steel bars or cables are stretched into tension before the concrete hardens; in post-tensioned concrete, the embedded steel bars or cables are stretched into tension after the concrete hardens
Richter Scale -
used to measure the magnitude of an earthquake; introduced in 1935 by the seismologists Beno Gutenberg and Charles Francis Richter
Rigid -
(adj.) ability to resist deformation when subjected to a load; rigidity (n.) the measure of a structure's ability not to change shape when subjected to a load
Rock Tunnel -
a passage constructed through solid rock
Shear -
a force that causes parts of a material to slide past one another in opposite directions
Shear-Walls -
solid concrete walls that resist shear forces; often used in buildings constructed in earthquake zones
Silt -
sediment particles ranging from 0.004 to 0.06 mm (0.00016 to 0.0024 inch) in diameter
Soft-Ground Tunnels -
a passage constructed through loose, unstable, or wet ground, requiring supports to keep the walls from collapsing
Span -
(n.) the distance a bridge extends between two supports; (v.) to traverse a specific distance
Spillway -
an overflow channel that allows dam operators to release lake water when it gets high enough to threaten the safety of a dam
Spire -
an architectural or decorative feature of a skyscraper; the Council on Tall Buildings and Urban Habitat includes spires but not antennae when calculating the official height of a skyscraper
Stable -
(adj.) ability to resist collapse and deformation; stability (n.) characteristic of a structure that is able to carry a realistic load without collapsing or deforming significantly
Steel -
an alloy of iron and carbon that is hard, strong, and malleable
Stiff -
(adj.) ability to resist deformation; stiffness (n.) the measure of a structure's capacity to resist deformation
Strong -
(adj.) ability to carry a realistic load; strength (n.) the measure of a structure's ability to carry a realistic load
Structural Engineer -
an engineer who investigates the behavior and design of all kinds of structures, including dams, domes, tunnels, bridges, and skyscrapers, to make sure they are safe and sound for human use
Suspension Bridge -
a bridge in which the roadway deck is suspended from cables that pass over two towers; the cables are anchored in housings at either end of the bridge
Tailings Dam -
a dam, usually made of earth and rock, used to contain mining waste
Tensegrity -
an array of tension cables and compression rods that supports a structure; invented by Buckminster Fuller student Kenneth Snellson
Tension -
a stretching force that pulls on a material
Tension Ring -
a support ring that resists the outward force pushing against the lower sides of a dome
Torsion -
an action that twists a material
Tower -
the vertical structure in a suspension bridge or cable-stayed bridge from which cables are hung; also used loosely as a synonym for the term skyscraper
Truss -
a rigid frame composed of short, straight pieces joined to form a series of triangles or other stable shapes
Tuned Mass Damper -
a mechanical counterweight designed to reduce the effects of motion, such as the swaying of a skyscraper in the wind or in an earthquake
Tunnel Boring Machine (TBM) -
a mechanical device that tunnels through the ground
Tunnel Shield -
a cylinder pushed ahead of tunneling equipment to provide advance support for the tunnel roof; used when tunneling in soft or unstable ground
Unstable -
characteristic of a structure that collapses or deforms under a realistic load
Upstream Face -
the side of a dam that is against the water
Wood -
a common natural material strong in both compression and tension
Wrought Iron -
an iron alloy that is less brittle than cast iron