· In chain surveying only linear distances on the field are measured. · These distances are used to define the boundary of field and mark simple details. Principle : It is to form a network of triangles by using the distances measured. Better accuracy will be obtained if the triangles thus formed are nearly equilateral in shape….
Spray gun, painting tool using compressed air from a nozzle to atomize a liquid into a controlled pattern. The spray nozzle operates by impinging high-velocity turbulent air on the surface of filaments or films of liquid, causing them to collapse to droplets with a wide range of sizes. spray The spray gun, developed originally from the airbrush, is…
Shell structure, in building construction, a thin, curved plate structure shaped to transmit applied forces by compressive, tensile, and shear stresses that act in the plane of the surface. They are usually constructed of concrete reinforced with steel mesh . Shell construction began in the 1920s; the shell emerged as a major long-span concrete structure after World War II….
Drum, in architecture, any of the cylindrical stone blocks composing a column that is not a monolith. The term also denotes a circular or polygonal wall supporting a dome, cupola, or lantern (qq.v.). Cupola Cupola, in architecture, small dome, often resembling an overturned cup, placed on a circular, polygonal, or square base or on small pillars or a glassed-in lantern. It is used to crown a turret, roof, or…
Dome, in architecture, hemispherical structure evolved from the arch, usually forming a ceiling or roof. Domes first appeared as solid mounds and in techniques adaptable only to the smallest buildings, such as round huts and tombs in the ancient Middle East, India, and the Mediterranean. The Romans introduced the large-scale masonry hemisphere. The dome exerts thrusts all around its perimeter, and…
Vault, in building construction, a structural member consisting of an arrangement of arches, usually forming a ceiling or roof. The basic barrel form, which appeared first in ancient Egypt and the Middle East, is in effect a continuous series of arches deep enough to cover a three-dimensional space. It exerts the same kind of thrust as the circular arch and must be buttressed along its entire…
Membrane structure, Structure with a thin, flexible surface (membrane) that carries loads primarily through tensile stresses. There are two main types: tent structures and pneumatic structures. The Denver International Airport (1995) features a terminal building roofed by a white membrane stretched from steel masts. Another such structure is London’s The O2 (formerly Millennium Dome), which has a tensioned membrane structure with…
Cable structure, Form of long-span structure that is subject to tension and uses suspension cables for support. Highly efficient, cable structures include the suspension bridge, the cable-stayed roof, and the bicycle-wheel roof. The graceful curve of the huge main cables of a suspension bridge is almost a catenary, the shape assumed by any string or cable suspended freely…
Girder, in building construction, a horizontal main supporting beam that carries a vertical concentrated load. girder Beam Beam, in engineering, originally a solid piece of timber, as a beam of a house, a plow, a loom, or a balance. In building construction, a beam is a horizontal member spanning an opening and carrying a load that may…
Framed building, structure in which weight is carried by a skeleton or framework, as opposed to being supported by walls. The essential factor in a framed building is the frame’s strength. Timber-framed or half-timbered houses were common in medieval Europe. In this type the frame is filled in with wattle and daub or brick. A modern lightweight wood-frame structure, the balloon-frame…