bridge_definitions

 **Glossary of Term**  **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   <span style="font-family: Times New Roman, serif;"> force   <span style="font-family: Times New Roman, serif;"> of its own weight, and of any weight pressing down on top of it, into an outward force along its sides and base <span style="font-family: Times New Roman, serif;"> **Arch Dam**  <span style="font-family: Times New Roman, serif;"> - a dam with an arched shape that resists the   <span style="font-family: Times New Roman, serif;"> force   <span style="font-family: Times New Roman, serif;"> of water   <span style="font-family: Times New Roman, serif;"> pressure   <span style="font-family: Times New Roman, serif;"> ; requires less material than a   <span style="font-family: Times New Roman, serif;"> gravity dam   <span style="font-family: Times New Roman, serif;"> for the same distance <span style="font-family: Times New Roman, serif;"> **Architect**  <span style="font-family: Times New Roman, serif;"> -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,   <span style="font-family: Times New Roman, serif;"> engineers   <span style="font-family: Times New Roman, serif;">, government officials, and construction crews <span style="font-family: Times New Roman, serif;"> **Beam**  <span style="font-family: Times New Roman, serif;"> - a   <span style="font-family: Times New Roman, serif;"> rigid   <span style="font-family: Times New Roman, serif;">, usually horizontal, structural element <span style="font-family: Times New Roman, serif;"> **Beam Bridge**  <span style="font-family: Times New Roman, serif;"> - a simple type of bridge, composed of horizontal   <span style="font-family: Times New Roman, serif;"> beams   <span style="font-family: Times New Roman, serif;"> supported by vertical posts <span style="font-family: Times New Roman, serif;"> **Bedrock**  <span style="font-family: Times New Roman, serif;"> -the solid rock layer beneath sand or   <span style="font-family: Times New Roman, serif;"> silt   <span style="font-family: Times New Roman, serif;"> <span style="font-family: Times New Roman, serif;"> **Bend**  <span style="font-family: Times New Roman, serif;"> -   <span style="font-family: Times New Roman, serif;"> **(v.)**   <span style="font-family: Times New Roman, serif;"> to curve; bending occurs when a straight material becomes curved; one side squeezes together in   <span style="font-family: Times New Roman, serif;"> compression   <span style="font-family: Times New Roman, serif;">, and the other side stretches apart in   <span style="font-family: Times New Roman, serif;"> tension <span style="font-family: Times New Roman, serif;"> **Bends**  <span style="font-family: Times New Roman, serif;"> -   <span style="font-family: Times New Roman, serif;"> **(n.)**   <span style="font-family: Times New Roman, serif;"> see   <span style="font-family: Times New Roman, serif;"> caisson disease <span style="font-family: Times New Roman, serif;"> **Brace**  <span style="font-family: Times New Roman, serif;"> -   <span style="font-family: Times New Roman, serif;"> **(n.)**   <span style="font-family: Times New Roman, serif;"> a structural support;   <span style="font-family: Times New Roman, serif;"> **(v.)**   <span style="font-family: Times New Roman, serif;"> to   <span style="font-family: Times New Roman, serif;"> strengthen   <span style="font-family: Times New Roman, serif;"> and   <span style="font-family: Times New Roman, serif;"> stiffen   <span style="font-family: Times New Roman, serif;"> a structure to resist   <span style="font-family: Times New Roman, serif;"> loads <span style="font-family: Times New Roman, serif;"> **Brittle**  <span style="font-family: Times New Roman, serif;"> -characteristic of a material that fails without warning;   <span style="font-family: Times New Roman, serif;"> **brittle**   <span style="font-family: Times New Roman, serif;"> materials do not stretch or shorten before failing <span style="font-family: Times New Roman, serif;"> **Buckle**  <span style="font-family: Times New Roman, serif;"> - to   <span style="font-family: Times New Roman, serif;"> bend   <span style="font-family: Times New Roman, serif;"> under   <span style="font-family: Times New Roman, serif;"> compression   <span style="font-family: Times New Roman, serif;"> <span style="font-family: Times New Roman, serif;"> **Buttress**  <span style="font-family: Times New Roman, serif;"> - a support that transmits a   <span style="font-family: Times New Roman, serif;"> force   <span style="font-family: Times New Roman, serif;"> from a roof or wall to another supporting structure <span style="font-family: Times New Roman, serif;"> **Buttress Dam**  <span style="font-family: Times New Roman, serif;"> - a   <span style="font-family: Times New Roman, serif;"> gravity dam   <span style="font-family: Times New Roman, serif;"> reinforced by structural supports <span style="font-family: Times New Roman, serif;"> **Cable**  <span style="font-family: Times New Roman, serif;"> - a structural element formed from   <span style="font-family: Times New Roman, serif;"> steel   <span style="font-family: Times New Roman, serif;"> wire bound in strands; the suspending element in a bridge; the supporting element in some dome roofs <span style="font-family: Times New Roman, serif;"> **Cable-Stayed Bridge**  <span style="font-family: Times New Roman, serif;"> -a bridge in which the roadway   <span style="font-family: Times New Roman, serif;"> deck   <span style="font-family: Times New Roman, serif;"> is suspended from   <span style="font-family: Times New Roman, serif;"> cables   <span style="font-family: Times New Roman, serif;"> anchored to one or more   <span style="font-family: Times New Roman, serif;"> towers <span style="font-family: Times New Roman, serif;"> **Caisson**  <span style="font-family: Times New Roman, serif;"> -a watertight, dry chamber in which people can work underwater <span style="font-family: Times New Roman, serif;"> **Caisson Disease**  <span style="font-family: Times New Roman, serif;"> -an affliction developed by people moving in and out of   <span style="font-family: Times New Roman, serif;"> caissons   <span style="font-family: Times New Roman, serif;"> quickly; also called the bends and decompression sickness <span style="font-family: Times New Roman, serif;"> **Cantilever**  <span style="font-family: Times New Roman, serif;"> -a projecting structure supported only at one end, like a shelf bracket or a diving board <span style="font-family: Times New Roman, serif;"> **Cast Iron**  <span style="font-family: Times New Roman, serif;"> - a   <span style="font-family: Times New Roman, serif;"> brittle   <span style="font-family: Times New Roman, serif;"> alloy with high carbon content;   <span style="font-family: Times New Roman, serif;"> iron   <span style="font-family: Times New Roman, serif;"> that has been melted, then poured into a form and cooled; can be made into any shape desired <span style="font-family: Times New Roman, serif;"> **Civil Engineer**  <span style="font-family: Times New Roman, serif;"> -an   <span style="font-family: Times New Roman, serif;"> engineer   <span style="font-family: Times New Roman, serif;"> who plans, designs, and supervises the construction of facilities essential to modern life <span style="font-family: Times New Roman, serif;"> **Cement**  <span style="font-family: Times New Roman, serif;"> -a binding material, or glue, that helps   <span style="font-family: Times New Roman, serif;"> concrete   <span style="font-family: Times New Roman, serif;"> harden <span style="font-family: Times New Roman, serif;"> **Coffer**  <span style="font-family: Times New Roman, serif;"> -a sunken panel in a ceiling <span style="font-family: Times New Roman, serif;"> **Cofferdam**  <span style="font-family: Times New Roman, serif;"> -a temporary dam built to divert a river around a construction site so the dam can be built on dry ground <span style="font-family: Times New Roman, serif;"> **Column**  <span style="font-family: Times New Roman, serif;"> - a vertical, structural element, strong in   <span style="font-family: Times New Roman, serif;"> compression <span style="font-family: Times New Roman, serif;"> **Compressed-Air Chamber**  <span style="font-family: Times New Roman, serif;"> -the space at the bottom of a   <span style="font-family: Times New Roman, serif;"> caisson   <span style="font-family: Times New Roman, serif;"> into which air is introduced under   <span style="font-family: Times New Roman, serif;"> pressure   <span style="font-family: Times New Roman, serif;"> to exclude water so that excavation can take place <span style="font-family: Times New Roman, serif;"> **Compression**  <span style="font-family: Times New Roman, serif;"> - a pressing   <span style="font-family: Times New Roman, serif;"> force   <span style="font-family: Times New Roman, serif;"> that squeezes a material together <span style="font-family: Times New Roman, serif;"> **Concrete**  <span style="font-family: Times New Roman, serif;"> -a mixture of water, sand, small stones, and a gray powder called   <span style="font-family: Times New Roman, serif;"> cement <span style="font-family: Times New Roman, serif;"> **Construction Manager**  <span style="font-family: Times New Roman, serif;"> -a person who coordinates the entire construction process -- from initial planning and foundation work through the structure's completion <span style="font-family: Times New Roman, serif;"> **Continuous Span Beam Bridge**  <span style="font-family: Times New Roman, serif;"> -simple bridge made by linking one   <span style="font-family: Times New Roman, serif;"> beam bridge   <span style="font-family: Times New Roman, serif;"> to another; some of the longest bridges in the world are   <span style="font-family: Times New Roman, serif;"> **continuous span beam bridges** <span style="font-family: Times New Roman, serif;"> **Core**  <span style="font-family: Times New Roman, serif;"> -central region of a skyscraper; usually houses elevator and stairwell <span style="font-family: Times New Roman, serif;"> **Cut and Cover**  <span style="font-family: Times New Roman, serif;"> -a method of tunnel construction that involves digging a trench, building a tunnel, and then covering it with fill <span style="font-family: Times New Roman, serif;"> **Deck**  <span style="font-family: Times New Roman, serif;"> -supported roadway on a bridge <span style="font-family: Times New Roman, serif;"> **Deform**  <span style="font-family: Times New Roman, serif;"> -to change shape <span style="font-family: Times New Roman, serif;"> **Diversion Channel**  <span style="font-family: Times New Roman, serif;"> -a bypass created to divert water around a dam so that construction can take place <span style="font-family: Times New Roman, serif;"> **Dome**  <span style="font-family: Times New Roman, serif;"> -a curved roof enclosing a circular space; a three-dimensional arch <span style="font-family: Times New Roman, serif;"> **Downstream Face**  <span style="font-family: Times New Roman, serif;"> -the side of the dam that is not against the water <span style="font-family: Times New Roman, serif;"> **Dynamite**  <span style="font-family: Times New Roman, serif;"> -a blasting explosive, based on   <span style="font-family: Times New Roman, serif;"> nitroglycerin   <span style="font-family: Times New Roman, serif;">, but much safer to handle than nitroglycerin alone <span style="font-family: Times New Roman, serif;"> **Electrical Engineer**  <span style="font-family: Times New Roman, serif;"> -an   <span style="font-family: Times New Roman, serif;"> engineer   <span style="font-family: Times New Roman, serif;"> concerned with electrical devices and systems and with the use of electrical energy <span style="font-family: Times New Roman, serif;"> **Embankment Dam**  <span style="font-family: Times New Roman, serif;"> -a dam composed of a mound of earth and rock; the simplest type of   <span style="font-family: Times New Roman, serif;"> gravity dam   <span style="font-family: Times New Roman, serif;"> <span style="font-family: Times New Roman, serif;"> **Engineering**  <span style="font-family: Times New Roman, serif;"> -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 <span style="font-family: Times New Roman, serif;"> **Environmental Engineer**  <span style="font-family: Times New Roman, serif;"> -an   <span style="font-family: Times New Roman, serif;"> engineer   <span style="font-family: Times New Roman, serif;"> 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 <span style="font-family: Times New Roman, serif;"> **Fire-Setting**  <span style="font-family: Times New Roman, serif;"> -an ancient tunneling technique in which rock is heated with fire and then doused with cold water, causing the rock to fracture <span style="font-family: Times New Roman, serif;"> **Force**  <span style="font-family: Times New Roman, serif;"> - any action that tends to maintain or alter the position of a structure <span style="font-family: Times New Roman, serif;"> **Geodesic Dome**  <span style="font-family: Times New Roman, serif;"> -a dome composed of short, straight pieces joined to form triangles; invented by Buckminster Fuller <span style="font-family: Times New Roman, serif;"> **Geotechnical Engineer**  <span style="font-family: Times New Roman, serif;"> -an   <span style="font-family: Times New Roman, serif;"> engineer   <span style="font-family: Times New Roman, serif;"> who evaluates and stabilizes foundations for buildings, roads, and other structures <span style="font-family: Times New Roman, serif;"> **Gravity Dam**  <span style="font-family: Times New Roman, serif;"> -a dam constructed so that its great weight resists the   <span style="font-family: Times New Roman, serif;"> force   <span style="font-family: Times New Roman, serif;"> of water   <span style="font-family: Times New Roman, serif;"> pressure   <span style="font-family: Times New Roman, serif;"> <span style="font-family: Times New Roman, serif;"> **Gunpowder**  <span style="font-family: Times New Roman, serif;"> -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 <span style="font-family: Times New Roman, serif;"> **Iron**  <span style="font-family: Times New Roman, serif;"> -a chemical element (Fe); one of the cheapest and most used metals <span style="font-family: Times New Roman, serif;"> **Joint**  <span style="font-family: Times New Roman, serif;"> - a device connecting two or more adjacent parts of a structure; a   <span style="font-family: Times New Roman, serif;"> **roller joint**   <span style="font-family: Times New Roman, serif;"> allows adjacent parts to move controllably past one another; a   <span style="font-family: Times New Roman, serif;"> **rigid joint**   <span style="font-family: Times New Roman, serif;"> prevents adjacent parts from moving or rotating past one another <span style="font-family: Times New Roman, serif;"> **Load**  <span style="font-family: Times New Roman, serif;"> - weight distribution throughout a structure;   <span style="font-family: Times New Roman, serif;"> **loads**   <span style="font-family: Times New Roman, serif;"> caused by wind, earthquakes, and gravity, for example, affect how weight is distributed throughout a structure <span style="font-family: Times New Roman, serif;"> **Masonry**  <span style="font-family: Times New Roman, serif;"> - a building material such as stone, clay, brick, or   <span style="font-family: Times New Roman, serif;"> concrete   <span style="font-family: Times New Roman, serif;"> <span style="font-family: Times New Roman, serif;"> **Mechanical Engineer**  <span style="font-family: Times New Roman, serif;"> -an   <span style="font-family: Times New Roman, serif;"> engineer   <span style="font-family: Times New Roman, serif;"> who applies the principles of mechanics and energy to the design of machines and devices <span style="font-family: Times New Roman, serif;"> **Monolithic Dome**  <span style="font-family: Times New Roman, serif;"> -a dome composed of a series of arches, joined together with a series of horizontal rings called parallels <span style="font-family: Times New Roman, serif;"> **Movable Bridge**  <span style="font-family: Times New Roman, serif;"> -a bridge in which the   <span style="font-family: Times New Roman, serif;"> deck   <span style="font-family: Times New Roman, serif;"> moves to clear a navigation channel; a   <span style="font-family: Times New Roman, serif;"> **swing bridge**   <span style="font-family: Times New Roman, serif;"> has a deck that rotates around a center point; a   <span style="font-family: Times New Roman, serif;"> **drawbridge**   <span style="font-family: Times New Roman, serif;"> has a deck that can be raised and lowered; a   <span style="font-family: Times New Roman, serif;"> **bascule bridge**   <span style="font-family: Times New Roman, serif;"> deck is raised with counterweights like a drawbridge; and the deck of a   <span style="font-family: Times New Roman, serif;"> **lift bridge**   <span style="font-family: Times New Roman, serif;"> is raised vertically like a massive elevator <span style="font-family: Times New Roman, serif;"> **Nitroglycerin**  <span style="font-family: Times New Roman, serif;"> -an explosive compound made from a mixture of glycerol and concentrated nitric and sulfuric acids, and an important ingredient of most forms of   <span style="font-family: Times New Roman, serif;"> dynamite   <span style="font-family: Times New Roman, serif;"> <span style="font-family: Times New Roman, serif;"> **Perimeter**  <span style="font-family: Times New Roman, serif;"> -the distance around the outside of a shape <span style="font-family: Times New Roman, serif;"> **Pier**  <span style="font-family: Times New Roman, serif;"> -a vertical supporting structure, such as a pillar <span style="font-family: Times New Roman, serif;"> **Pendentive**  <span style="font-family: Times New Roman, serif;"> -a triangular shape that adapts the circular ring of a dome to fit onto a flat supporting wall <span style="font-family: Times New Roman, serif;"> **Pile**  <span style="font-family: Times New Roman, serif;"> - a long, round pole of   <span style="font-family: Times New Roman, serif;"> wood   <span style="font-family: Times New Roman, serif;">,   <span style="font-family: Times New Roman, serif;"> concrete   <span style="font-family: Times New Roman, serif;"> , or   <span style="font-family: Times New Roman, serif;"> steel   <span style="font-family: Times New Roman, serif;"> driven into the soil by   <span style="font-family: Times New Roman, serif;"> pile drivers   <span style="font-family: Times New Roman, serif;"> <span style="font-family: Times New Roman, serif;"> **Pile Driver**  <span style="font-family: Times New Roman, serif;"> -a noisy machine that repeatedly drops a heavy weight on top of a   <span style="font-family: Times New Roman, serif;"> pile   <span style="font-family: Times New Roman, serif;"> until the pile reaches solid soil or rock or cannot be pushed down any farther <span style="font-family: Times New Roman, serif;"> **Plastic**  <span style="font-family: Times New Roman, serif;"> -a synthetic material made from long chains of molecules; has the capability of being molded or shaped, usually by the application of heat and   <span style="font-family: Times New Roman, serif;"> pressure   <span style="font-family: Times New Roman, serif;"> <span style="font-family: Times New Roman, serif;"> **Pressure**  <span style="font-family: Times New Roman, serif;"> - a   <span style="font-family: Times New Roman, serif;"> force   <span style="font-family: Times New Roman, serif;"> applied or distributed over an area <span style="font-family: Times New Roman, serif;"> **Reinforced Concrete**  <span style="font-family: Times New Roman, serif;"> -   <span style="font-family: Times New Roman, serif;"> concrete   <span style="font-family: Times New Roman, serif;"> with   <span style="font-family: Times New Roman, serif;"> steel   <span style="font-family: Times New Roman, serif;"> bars or mesh embedded in it for increased   <span style="font-family: Times New Roman, serif;"> strength   <span style="font-family: Times New Roman, serif;"> in   <span style="font-family: Times New Roman, serif;"> tension   <span style="font-family: Times New Roman, serif;"> ; in   <span style="font-family: Times New Roman, serif;"> **pre-tensioned concrete**   <span style="font-family: Times New Roman, serif;">, the embedded steel bars or cables are stretched into tension before the concrete hardens; in   <span style="font-family: Times New Roman, serif;"> **post-tensioned concrete**   <span style="font-family: Times New Roman, serif;"> , the embedded steel bars or cables are stretched into tension after the concrete hardens <span style="font-family: Times New Roman, serif;"> **Richter Scale**  <span style="font-family: Times New Roman, serif;"> -used to measure the magnitude of an earthquake; introduced in 1935 by the seismologists Beno Gutenberg and Charles Francis Richter <span style="font-family: Times New Roman, serif;"> **Rigid**  <span style="font-family: Times New Roman, serif;"> -   <span style="font-family: Times New Roman, serif;"> **(adj.)**   <span style="font-family: Times New Roman, serif;"> ability to resist   <span style="font-family: Times New Roman, serif;"> deformation   <span style="font-family: Times New Roman, serif;"> when subjected to a   <span style="font-family: Times New Roman, serif;"> load   <span style="font-family: Times New Roman, serif;"> ;   <span style="font-family: Times New Roman, serif;"> **rigidity**   <span style="font-family: Times New Roman, serif;">   <span style="font-family: Times New Roman, serif;"> **(n.)**   <span style="font-family: Times New Roman, serif;"> the measure of a structure's ability not to change shape when subjected to a   <span style="font-family: Times New Roman, serif;"> load   <span style="font-family: Times New Roman, serif;"> <span style="font-family: Times New Roman, serif;"> **Rock Tunnel**  <span style="font-family: Times New Roman, serif;"> - a passage constructed through solid rock <span style="font-family: Times New Roman, serif;"> **Shear**  <span style="font-family: Times New Roman, serif;"> - a   <span style="font-family: Times New Roman, serif;"> force   <span style="font-family: Times New Roman, serif;"> that causes parts of a material to slide past one another in opposite directions <span style="font-family: Times New Roman, serif;"> **Shear-Walls**  <span style="font-family: Times New Roman, serif;"> - solid   <span style="font-family: Times New Roman, serif;"> concrete   <span style="font-family: Times New Roman, serif;"> walls that resist   <span style="font-family: Times New Roman, serif;"> shear   <span style="font-family: Times New Roman, serif;">   <span style="font-family: Times New Roman, serif;"> forces   <span style="font-family: Times New Roman, serif;"> ; often used in buildings constructed in earthquake zones <span style="font-family: Times New Roman, serif;"> **Silt**  <span style="font-family: Times New Roman, serif;"> - sediment particles ranging from 0.004 to 0.06 mm (0.00016 to 0.0024 inch) in diameter <span style="font-family: Times New Roman, serif;"> **Soft-Ground Tunnels**  <span style="font-family: Times New Roman, serif;"> -a passage constructed through loose,   <span style="font-family: Times New Roman, serif;"> unstable   <span style="font-family: Times New Roman, serif;">, or wet ground, requiring supports to keep the walls from collapsing <span style="font-family: Times New Roman, serif;"> **Span**  <span style="font-family: Times New Roman, serif;"> -   <span style="font-family: Times New Roman, serif;"> **(n.)**   <span style="font-family: Times New Roman, serif;"> the distance a bridge extends between two supports;   <span style="font-family: Times New Roman, serif;"> **(v.)**   <span style="font-family: Times New Roman, serif;"> to traverse a specific distance <span style="font-family: Times New Roman, serif;"> **Spillway**  <span style="font-family: Times New Roman, serif;"> -an overflow channel that allows dam operators to release lake water when it gets high enough to threaten the safety of a dam <span style="font-family: Times New Roman, serif;"> **Spire**  <span style="font-family: Times New Roman, serif;"> -an architectural or decorative feature of a skyscraper; the Council on Tall Buildings and Urban Habitat includes   <span style="font-family: Times New Roman, serif;"> **spires**   <span style="font-family: Times New Roman, serif;"> but not antennae when calculating the official height of a skyscraper <span style="font-family: Times New Roman, serif;"> **Stable**  <span style="font-family: Times New Roman, serif;"> -   <span style="font-family: Times New Roman, serif;"> **(adj.)**   <span style="font-family: Times New Roman, serif;"> ability to resist collapse and   <span style="font-family: Times New Roman, serif;"> deformation   <span style="font-family: Times New Roman, serif;"> ;   <span style="font-family: Times New Roman, serif;"> **stability (n.)**   <span style="font-family: Times New Roman, serif;"> characteristic of a structure that is able to carry a realistic   <span style="font-family: Times New Roman, serif;"> load   <span style="font-family: Times New Roman, serif;"> without collapsing or   <span style="font-family: Times New Roman, serif;"> deforming   <span style="font-family: Times New Roman, serif;"> significantly <span style="font-family: Times New Roman, serif;"> **Steel**  <span style="font-family: Times New Roman, serif;"> - an alloy of   <span style="font-family: Times New Roman, serif;"> iron   <span style="font-family: Times New Roman, serif;"> and carbon that is hard,   <span style="font-family: Times New Roman, serif;"> strong   <span style="font-family: Times New Roman, serif;">, and malleable <span style="font-family: Times New Roman, serif;"> **Stiff**  <span style="font-family: Times New Roman, serif;"> -   <span style="font-family: Times New Roman, serif;"> **(adj.)**   <span style="font-family: Times New Roman, serif;"> ability to resist   <span style="font-family: Times New Roman, serif;"> deformation   <span style="font-family: Times New Roman, serif;"> ;   <span style="font-family: Times New Roman, serif;"> **stiffness (n.)**   <span style="font-family: Times New Roman, serif;"> the measure of a structure's capacity to resist   <span style="font-family: Times New Roman, serif;"> deformation   <span style="font-family: Times New Roman, serif;"> <span style="font-family: Times New Roman, serif;"> **Story**  <span style="font-family: Times New Roman, serif;"> -floor of a skyscraper <span style="font-family: Times New Roman, serif;"> **Strong**  <span style="font-family: Times New Roman, serif;"> -   <span style="font-family: Times New Roman, serif;"> **(adj.)**   <span style="font-family: Times New Roman, serif;"> ability to carry a realistic   <span style="font-family: Times New Roman, serif;"> load   <span style="font-family: Times New Roman, serif;"> ;   <span style="font-family: Times New Roman, serif;"> **strength (n.)**   <span style="font-family: Times New Roman, serif;"> the measure of a structure's ability to carry a realistic   <span style="font-family: Times New Roman, serif;"> load <span style="font-family: Times New Roman, serif;"> **Structural Engineer**  <span style="font-family: Times New Roman, serif;"> -an   <span style="font-family: Times New Roman, serif;"> engineer   <span style="font-family: Times New Roman, serif;"> 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 <span style="font-family: Times New Roman, serif;"> **Suspension Bridge**  <span style="font-family: Times New Roman, serif;"> - a bridge in which the roadway   <span style="font-family: Times New Roman, serif;"> deck   <span style="font-family: Times New Roman, serif;"> is suspended from   <span style="font-family: Times New Roman, serif;"> cables   <span style="font-family: Times New Roman, serif;"> that pass over two   <span style="font-family: Times New Roman, serif;"> towers   <span style="font-family: Times New Roman, serif;"> ; the cables are anchored in housings at either end of the bridge <span style="font-family: Times New Roman, serif;"> **Tailings Dam**  <span style="font-family: Times New Roman, serif;"> -a dam, usually made of earth and rock, used to contain mining waste <span style="font-family: Times New Roman, serif;"> **Tensegrity**  <span style="font-family: Times New Roman, serif;"> -an array of   <span style="font-family: Times New Roman, serif;"> tension   <span style="font-family: Times New Roman, serif;">   <span style="font-family: Times New Roman, serif;"> cables   <span style="font-family: Times New Roman, serif;"> and   <span style="font-family: Times New Roman, serif;"> compression   <span style="font-family: Times New Roman, serif;"> rods that supports a structure; invented by Buckminster Fuller student Kenneth Snellson <span style="font-family: Times New Roman, serif;"> **Tension**  <span style="font-family: Times New Roman, serif;"> - a stretching   <span style="font-family: Times New Roman, serif;"> force   <span style="font-family: Times New Roman, serif;"> that pulls on a material <span style="font-family: Times New Roman, serif;"> **Tension Ring**  <span style="font-family: Times New Roman, serif;"> -a support ring that resists the outward   <span style="font-family: Times New Roman, serif;"> force   <span style="font-family: Times New Roman, serif;"> pushing against the lower sides of a dome <span style="font-family: Times New Roman, serif;"> **Torsion**  <span style="font-family: Times New Roman, serif;"> -an action that twists a material <span style="font-family: Times New Roman, serif;"> **Tower**  <span style="font-family: Times New Roman, serif;"> -the vertical structure in a   <span style="font-family: Times New Roman, serif;"> suspension bridge   <span style="font-family: Times New Roman, serif;"> or   <span style="font-family: Times New Roman, serif;"> cable-stayed bridge   <span style="font-family: Times New Roman, serif;"> from which   <span style="font-family: Times New Roman, serif;"> cables   <span style="font-family: Times New Roman, serif;"> are hung; also used loosely as a synonym for the term skyscraper <span style="font-family: Times New Roman, serif;"> **Truss**  <span style="font-family: Times New Roman, serif;"> - a   <span style="font-family: Times New Roman, serif;"> rigid   <span style="font-family: Times New Roman, serif;"> frame composed of short, straight pieces joined to form a series of triangles or other   <span style="font-family: Times New Roman, serif;"> stable   <span style="font-family: Times New Roman, serif;"> shapes <span style="font-family: Times New Roman, serif;"> **Tuned Mass Damper**  <span style="font-family: Times New Roman, serif;"> -a mechanical counterweight designed to reduce the effects of motion, such as the swaying of a skyscraper in the wind or in an earthquake <span style="font-family: Times New Roman, serif;"> **Tunnel Boring Machine (TBM)**  <span style="font-family: Times New Roman, serif;"> -a mechanical device that tunnels through the ground <span style="font-family: Times New Roman, serif;"> **Tunnel Shield**  <span style="font-family: Times New Roman, serif;"> -a cylinder pushed ahead of tunneling equipment to provide advance support for the tunnel roof; used when tunneling in soft or   <span style="font-family: Times New Roman, serif;"> unstable   <span style="font-family: Times New Roman, serif;"> ground <span style="font-family: Times New Roman, serif;"> **Unstable**  <span style="font-family: Times New Roman, serif;"> -characteristic of a structure that collapses or   <span style="font-family: Times New Roman, serif;"> deforms   <span style="font-family: Times New Roman, serif;"> under a realistic   <span style="font-family: Times New Roman, serif;"> load   <span style="font-family: Times New Roman, serif;"> <span style="font-family: Times New Roman, serif;"> **Upstream Face**  <span style="font-family: Times New Roman, serif;"> -the side of a dam that is against the water <span style="font-family: Times New Roman, serif;"> **Wood**  <span style="font-family: Times New Roman, serif;"> -a common natural material   <span style="font-family: Times New Roman, serif;"> strong   <span style="font-family: Times New Roman, serif;"> in both   <span style="font-family: Times New Roman, serif;"> compression   <span style="font-family: Times New Roman, serif;"> and   <span style="font-family: Times New Roman, serif;"> tension <span style="font-family: Times New Roman, serif;"> **Wrought Iron**  <span style="font-family: Times New Roman, serif;"> -an   <span style="font-family: Times New Roman, serif;"> iron   <span style="font-family: Times New Roman, serif;"> alloy that is less   <span style="font-family: Times New Roman, serif;"> brittle   <span style="font-family: Times New Roman, serif;"> than   <span style="font-family: Times New Roman, serif;"> cast iron page here.
 * include component="page" page="toolbar_tdj" editable="1" Bridge Definitions**