Artificial Structures

Artificial Structures

 

a term used to designate transportation structures (on railroads, highways, and city streets) erected at crossings of rivers, ravines, mountain ridges, and intersecting roads. The term “artificial structures” is arbitrary; it came into use because of the complexity of construction of such structures as compared with the strips required for railroad lines, highways, and city streets. The most widespread artificial structures on railroad and motor-vehicle roads and streets are bridges, viaducts, overpasses, trestles, drain conduits under embankments, and drainage and diversion ditches. Artificial road structures also include tunnels, avalanche-prevention areas and snowsheds, retaining walls, and other special structures erected on mountain roads.

Artificial structures in cities include transportation tunnels and overpasses to separate traffic into various levels, as well as elevated and underground pedestrian crossings. Artificial structures on highways and in cities are mainly built of reinforced concrete. The cost of the artificial structures is 10–15 percent of the total cost of a road. For modern expressways, which intersect all crossroads on overpasses or underpasses, and for mountain roads and railroads, the cost of artificial structures reaches 30–40 percent.

E. E. GIBSHMAN

References in classic literature ?
Would it be wonderful if, under the pressure of all these difficulties, the convention should have been forced into some deviations from that artificial structure and regular symmetry which an abstract view of the subject might lead an ingenious theorist to bestow on a Constitution planned in his closet or in his imagination?
It will also be repaired unsatisfactory state of artificial structures (bridges).
Sandia co-researcher Wally Paxton said, "This is foundational science, but one possibility we see, way down the road, is to use soft artificial structures like these to painlessly interface with the body's nerve structures.
Leader in France in aerial adventure parks and artificial structures, the Altiplano Group has different subsidiaries specializing in travel (Travelmania, Skimania, Oxymania), operations of aerial adventure parks (Treetop Quest, Indoor Aventures, France Aventures) and design and management of artificial recreational structures (Urban-Koncept).
Innovation in biomaterials and stem cells create the amazing opportunity to make tissues from scaffolds cells that are implanted or seeded into 3D artificial structures and influence tissue construction.
However, the spherical shape of a typical Luneburg lens is inconvenience in some applications, Cui said, which is why he and his colleagues used inhomogeneous artificial structures to create a flat surface that acts like a Luneburg lens.
Barracudas tend to be solitary but are also found in aggregations over prominent reef structures, particularly near artificial structures and shallow bank reefs.
Yet it seems every week brings a new revelation of another business that is using artificial structures to move profits out of the UK, seemingly for no purpose other than to avoid tax," said Margaret Hodge, chair of the Public Accounts Committee.
8:15 ASSESSING VULNERABILITY OF ARTIFICIAL STRUCTURES ALONG ESTUARINE SHORELINES IN SOUTH CAROLINA **, Adam R.
So much damage is done at schools when teachers impose artificial structures just to pass exams," Dr Fatma Khalifa, a lecturer in economics at one of the colleges in Muscat, said.
A few topics in this issue include: iron bioavailability in the Southern Ocean, anthropogenic nutrient enrichment and blooms of harmful phytoplankton, and changing coasts: marine aliens and artificial structures.
The shade of a tree, studies also show, is cooler than shade of artificial structures due to the moisture produced by foliage.