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 periodicals archive ?
Ashcroft's spokesman said the peer had never engaged in tax evasion or tax avoidance using artificial structures and "any suggestion he has will be vigorously challenged".
This offers a huge amount of flexibility in designing artificial structures for diverse magneto-electric and magneto-optical applications," co-senior author Steven Louie from Berkeley Lab said in (https://newscenter.
This volume consists of eight reviews of topics in oceanography and marine biology: the use of visual imaging for marine biological and ecological research; the ecology of macro and microtidal estuaries; concepts, definitions, and assessment of habitat complexity for demersal marine fish; biodiversity and ecosystem consequences of the proliferation of artificial structures in the sea; the ecophysiological responses of corals to environmental stressors; the ecological impacts of marine disposal of mine tailings; the ecological roles of exploited sea cucumbers; and multidecadal spatial and temporal variation in phytoplankton diversity in south-eastern Australia.
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.
8:15 ASSESSING VULNERABILITY OF ARTIFICIAL STRUCTURES ALONG ESTUARINE SHORELINES IN SOUTH CAROLINA **, Adam R.
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.
Once in the Gulf, they settle around natural and artificial structures to spawn.
He added: "These artificial structures could be used to encrypt information in optical signatures on banknotes or other valuable items to protect them against forgery.
On the country's east coast in Fujairah, a project launched eight months ago to deploy artificial structures to rehabilitate coral reefs is already attracting marine life.
Prosthetics is the fabrication and fitting of prosthetic devices (prostheses); or, the branch of surgery or dentistry that deals with the replacement of missing parts with artificial structures.
It quotes healthcare product manufacturer Johnson & Johnson as declaring that it will always "bear our fair share of taxes" while pharmaceutical group AstraZeneca states: "We draw a distinction between tax planning using artificial structures and optimising the tax treatment of business transactions--and we engage only in the latter.