1.
Gravel road
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A gravel road is a type of unpaved road surfaced with gravel that has been brought to the site from a quarry or stream bed. They are common in less-developed nations, and also in the areas of developed nations such as Canada. In New Zealand, and other Commonwealth countries, they may be known as metal roads and they may be referred to as dirt roads in common speech, but that term is used more for unimproved roads with no surface material added. If well constructed and maintained, a road is an all-weather road. Compared to sealed roads, which require large machinery to work and pour concrete or to lay and smooth a surface, gravel roads are easy. Graders are also used to produce a more extreme compared to a paved road to aid drainage, as well as to construct drainage ditches. Cellular confinement systems can be used to prevent the washboarding effect, the gravel used consists of varying amount of crushed stone, sand, and fines. Fines are silt or clay particles smaller than.075 millimetres, crushed stone is used because gravel with fractured faces will stay in place better than rounded river pebbles. A good gravel for a road will have a higher percentage of fines than gravel used as a subbase for a paved road. This often causes problems if a road is paved without adding sand. A gravel road is different from a gravel drive, popular as private driveways in the United Kingdom. This uses clean gravel consisting of uniform, rounded stones and small pebbles, in Africa and parts of Asia and South America, laterite soils are used to build dirt roads. However laterite, called murram in East Africa, varies considerably in the proportion of stones to earth and it ranges from a hard gravel to a softer earth embedded with small stones. Not all laterite and murram roads are therefore strictly gravel roads, as it dries out, such laterite can become very hard, like sun-dried bricks. Gravel roads require much more frequent maintenance than paved roads, especially wet periods. Wheel motion shoves material to the outside, leading to rutting, reduced water-runoff, as long as the process is interrupted early enough, simple re-grading is sufficient, with material being pushed back into shape. Segments of gravel roads on grades also rut easily as a result of flowing water, when grading or building the road, waterbars are used to direct water off the road. As an alternative method, humps can be formed in the gravel along the road to impede water flow, another problem with gravel roads is washboarding — the formation of corrugations across the surface at right angles to the direction of travel
2.
Terre Haute, Indiana
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Terre Haute is a city in and the county seat of Vigo County, Indiana, United States, near the states western border with Illinois. As of the 2010 census, the city had a population of 60,785. Located along the Wabash River, Terre Haute is the capital of the Wabash Valley. The city is home to higher education institutions, including Indiana State University, Saint Mary-of-the-Woods College. Terre Haute is notable for being the home of Socialist Party of America leader and five-time presidential nominee, Debs and the Federal Correctional Complex. Terre Haute is located alongside the bank of the Wabash River in western Indiana. The city lies about 75 miles west of Indianapolis, according to the 2010 census, Terre Haute has a total area of 35.272 square miles, of which 34.54 square miles is land and 0.732 square miles is water. The Wabash River dominates the geography of the city, forming its western border. Small bluffs on the east side of city mark the edge of the flood plain. Lost Creek and Honey Creek drain the northern and southern sections of the city, in the late 19th century, several oil and mineral wells were productive in and near the center of the city. That well produced oil into the 1920s, Terre Haute is at the intersection of two major roadways, U. S.40 from California to Maryland and US41 from Copper Harbor, Michigan to Miami, Florida. Terre Haute is located 77 miles southwest of Indianapolis and within 185 miles of Chicago, St. Louis, Louisville, Climate is characterized by relatively high temperatures and evenly distributed precipitation throughout the year. The Köppen Climate Classification subtype for this climate is Dfa, Terre Hautes name was derived from the French phrase terre haute, meaning Highland. It was likely named by French explorers in the area in the early 18th century to describe the unique location above the Wabash River, at the time the area was claimed by the French and British, these highlands were considered the border between Canada and Louisiana. The construction of Fort Harrison in 1811 marked the beginning of a permanent population of European-Americans. A Wea Indian village already existed near the fort, and the orchards, the village of Terre Haute, then a part of Knox County, Indiana, was platted in 1816. Growth really began when the founders won the bid to make it the county seat when Vigo County was formed in March 1818. When the villages 1,000 residents voted to incorporate in 1832, Terre Haute became a town, early Terre Haute was a center of farming, milling and pork processing
3.
Barge
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A barge is a flat-bottomed boat, built mainly for river and canal transport of heavy goods. Some barges are not self-propelled and must be towed or pushed by towboats, Barge is attested from 1300, from Old French barge, from Vulgar Latin barga. The word originally could refer to any small boat, the modern meaning arose around 1480, bark small ship is attested from 1420, from Old French barque, from Vulgar Latin barca. The more precise meaning three-masted ship arose in the 17th century, both are probably derived from the Latin barica, from Greek, βάρις, translit. Egyptian boat, from Coptic, ⲃⲁⲁⲣⲉ bāri small boat, hieroglyphic Egyptian, by extension, the term embark literally means to board the kind of boat called a barque. The long pole used to maneuver or propel a barge has given rise to the saying I wouldnt touch that with a barge pole. On the British canal system, the barge is used to describe a boat wider than a narrowboat. In the United States, deckhands perform the labor and are supervised by a leadman or the mate, the captain and pilot steer the towboat, which pushes one or more barges held together with rigging, collectively called the tow. The crew live aboard the towboat as it travels along the river system or the intracoastal waterways. These towboats travel between ports and are also called line-haul boats, poles are used on barges to fend off the barge as it nears other vessels or a wharf. These are often called pike poles, barges are used today for low-value bulk items, as the cost of hauling goods by barge is very low. Barges are also used for heavy or bulky items, a typical American barge measures 195 by 35 feet. The most common European barge measures 76.5 by 11.4 metres, as an example, on June 26,2006, a 565-short-ton catalytic cracking unit reactor was shipped by barge from the Tulsa Port of Catoosa in Oklahoma to a refinery in Pascagoula, Mississippi. Extremely large objects are normally shipped in sections and assembled onsite, of the reactors 700-mile journey, only about 40 miles were traveled overland, from the final port to the refinery. Canal barges are made for the particular canal in which they will operate. Many barges, primarily Dutch barges, which were designed for carrying cargo along the canals of Europe, are no longer large enough to compete in this industry with larger newer vessels. Many of these barges have been renovated and are now used as hotel barges carrying holidaymakers along the same canals on which they once carried grain or coal. This holds true today, for areas of the world
4.
Grain size
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Particle size, also called grain size, refers to the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials and this is different from the crystallite size, which refers to the size of a single crystal inside a particle or grain. A single grain can be composed of several crystals, granular material can range from very small colloidal particles, through clay, silt, sand, gravel, and cobbles, to boulders. Size ranges define limits of classes that are given names in the Wentworth scale used in the United States, the Krumbein phi scale, a modification of the Wentworth scale created by W. C. This equation can be rearranged to find diameter using φ, D = D0 ×2 − ϕ In some schemes, ISO 14688-1 is applicable to natural soils in situ, similar man-made materials in situ and soils redeposited by people. An accumulation of sediment can also be characterized by the size distribution. A sediment deposit can undergo sorting when a particle size range is removed by an agency such as a river or the wind, a Scale of Grade and Class Terms for Clastic Sediments
5.
Boulder
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In geology, a boulder is a rock fragment with size greater than 25.6 centimetres in diameter. Smaller pieces are called cobbles and pebbles, while a boulder may be small enough to move or roll manually, others are extremely massive. In common usage, a boulder is too large for a person to move, smaller boulders are usually just called rocks or stones. The word boulder is short for boulder stone, from Middle English bulderston or Swedish bullersten, in places covered by ice sheets during Ice Ages, such as Scandinavia, northern North America, and Siberia, glacial erratics are common. Erratics are boulders picked up by ice sheets during their advance and they are called erratic because they typically are of a different rock type than the bedrock on which they are deposited. One of them is used as the pedestal of the Bronze Horseman in Saint Petersburg, boulder sized clasts are found in some sedimentary rocks, such as coarse conglomerate and boulder clay. The climbing of large boulders is called bouldering, road debris Monolith Media related to Boulders at Wikimedia Commons
6.
Pebble
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A pebble is a clast of rock with a particle size of 2 to 64 millimetres based on the Krumbein phi scale of sedimentology. Pebbles are generally considered larger than granules and smaller than cobbles, a rock made predominantly of pebbles is termed a conglomerate. Pebble tools are among the earliest known man-made artifacts, dating from the Palaeolithic period of human history, a beach composed chiefly of surface pebbles is commonly termed a shingle beach. This type of beach has armoring characteristics with respect to wave erosion, as well as ecological niches that provide habitat for animals and plants. Inshore banks of shingle exist in locations, such as the entrance to the River Ore. Pebbles come in colors and textures and can have streaks, known as veins. Pebbles are mostly smooth but, dependent on how frequently they come in contact with the sea, pebbles left above the high water mark may have growths of organisms such as lichen on them, signifying the lack of contact with seawater. Pebbles are found in two locations – on the beaches of various oceans and seas, and inland where ancient seas used to cover the land, when then the seas retreated, the rocks became landlocked. They can also be found in lakes and ponds, pebbles can also form in rivers, and travel into estuaries where the smoothing continues in the sea. Beach pebbles and river pebbles are distinct in their geological formation, beach pebbles form gradually over time as the ocean water washes over loose rock particles. The result is a smooth, rounded appearance, the typical size range is from 2 mm to 50 mm. The colors range from translucent white to black, and include shades of yellow, brown, red and green. Some of the more plentiful pebble beaches are found along the coast of the Pacific Ocean, beginning in the United States and extending down to the tip of South America in Argentina. Other pebble beaches are found in northern Europe, along the coast of the U. K. and Ireland, on the shores of Australia, inland pebbles are usually found along the shores of large rivers and lakes. These pebbles form as the water washes over rock particles on the bottom. The smoothness and color of river pebbles depends on several factors, such as the composition of the soil of the banks, the chemical characteristics of the water. Because river current is gentler than the waves, river pebbles are usually not as smooth as beach pebbles. The most common colors of rock are black, grey, green, brown
7.
Road
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Roads consist of one or two roadways, each with one or more lanes and any associated sidewalks and road verges. Roads that are available for use by the public may be referred to as parkways, avenues, freeways, interstates, highways, or primary, secondary, and tertiary local roads. In urban areas roads may diverge through a city or village and be named as streets, serving a function as urban space easement. Modern roads are normally smoothed, paved, or otherwise prepared to allow easy travel, historically many roads were simply recognizable routes without any formal construction or maintenance. In the United Kingdom there is ambiguity between the terms highway and road. The Highway code details rules for road users and this includes footpaths, bridleways and cycle tracks, and also road and driveways on private land and many car parks. Vehicle Excise Duty, a use tax, is payable on some vehicles used on the public road. The definition of a road depends on the definition of a highway, in the United States, laws distinguish between public roads, which are open to public use, and private roads, which are privately controlled. The assertion that the first pathways were the trails made by animals has not been universally accepted, others believe that some roads originated from following animal trails. The Icknield Way is given as an example of type of road origination. By about 10,000 BC, rough roads/pathways were used by human travelers, the worlds oldest known paved road was constructed in Egypt some time between 2600 and 2200 BC. Stone-paved streets are found in the city of Ur in the Middle East dating back to 4000 BC, corduroy roads are found dating to 4000 BC in Glastonbury, England. The Sweet Track, a timber causeway in England, is one of the oldest engineered roads discovered. Built in winter 3807 BC or spring 3806 BC, tree-ring dating enabled very precise dating and it was claimed to be the oldest road in the world until the 2009 discovery of a 6, 000-year-old trackway in Plumstead, London. Brick-paved streets were used in India as early as 3000 BC, in 500 BC, Darius I the Great started an extensive road system for Persia, including the Royal Road, which was one of the finest highways of its time. The road remained in use after Roman times, a hybrid of road transport and ship transport beginning in about 1740 is the horse-drawn boat in which the horse follows a cleared path along the river bank. From about 312 BC, the Roman Empire built straight strong stone Roman roads throughout Europe and North Africa, at its peak the Roman Empire was connected by 29 major roads moving out from Rome and covering 78,000 kilometers or 52,964 Roman miles of paved roads. In the 8th century AD, many roads were built throughout the Arab Empire, the most sophisticated roads were those in Baghdad, which were paved with tar
8.
Road surface
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Road surface or pavement is the durable surface material laid down on an area intended to sustain vehicular or foot traffic, such as a road or walkway. In the past, gravel road surfaces, cobblestone and granite setts were extensively used, Road surfaces are frequently marked to guide traffic. Today, permeable paving methods are beginning to be used for low-impact roadways and walkways, asphalt, sometimes called flexible pavement due to the nature in which it distributes loads, has been widely used since the 1920s. The viscous nature of the bitumen binder allows asphalt concrete to sustain significant plastic deformation, most asphalt surfaces are laid on a gravel base, which is generally at least as thick as the asphalt layer, although some full depth asphalt surfaces are laid directly on the native subgrade. In areas with soft or expansive subgrades such as clay or peat. Depending on the temperature at which it is applied, asphalt is categorized as hot mix, warm mix, hot mix asphalt is applied at temperatures over 300 °F with a free floating screed. Warm mix asphalt is applied at temperatures of 200–250 °F, resulting in reduced energy usage, cold mix asphalt is often used on lower volume rural roads, where hot mix asphalt would cool too much on the long trip from the asphalt plant to the construction site. An asphalt concrete surface will generally be constructed for primary highways having an average annual daily traffic load greater than 1200 vehicles per day. Advantages of asphalt roadways include relatively low noise, relatively low cost compared with other paving methods, in the mid-1960s, rubberized asphalt was used for the first time, mixing crumb rubber from used tires with asphalt. Also, application of rubberized asphalt is more temperature-sensitive, and in many locations can only be applied at times of the year. Study results of the long-term acoustic benefits of rubberized asphalt are inconclusive, compared to traditional passive attenuating measures, rubberized asphalt provides shorter-lasting and lesser acoustic benefits at typically much greater expense. Concrete surfaces are created using a mix of Portland cement, coarse aggregate, sand. In many cases there will also be Portland cement substitutes added and this can reduce the cost of the concrete and improve its physical properties. The water allows the mix to combine molecularly in a reaction called hydration. Concrete surfaces have been refined into three types, jointed plain, jointed reinforced and continuously reinforced. The one item that each type is the jointing system used to control crack development. Jointed plain concrete pavements contain enough joints to control the location of all the expected shrinkage cracks, the concrete cracks at the joints and not elsewhere in the slabs. Jointed plain pavements do not contain any steel reinforcement, however, there may be smooth steel bars at transverse joints and deformed steel bars at longitudinal joints
9.
Rural area
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In general, a rural area or countryside is a geographic area that is located outside towns and cities. Whatever is not urban is considered rural, typical rural areas have a low population density and small settlements. Agricultural areas are rural, though so are others such as forests. Different countries have varying definitions of rural for statistical and administrative purposes, in Canada, the census division has been used to represent regions and census consolidated sub-divisions have been used to represent communities. Intermediate regions have 15 to 49 percent of their living in a rural community. Predominantly urban regions have less than 15 percent of their living in a rural community. Predominantly rural regions are classified as rural metro-adjacent, rural non-metro-adjacent and rural northern, following Ehrensaft, as well, rural northern regions encompass all of the Yukon, Northwest Territories and Nunavut. Statistics Canada defines rural for their population counts and this definition has changed over time. Typically, it has referred to the population living outside settlements of 1,000 or less inhabitants, the current definition states that census rural is the population outside settlements with fewer than 1,000 inhabitants and a population density below 400 people per square kilometre. 84% of the United States inhabitants live in suburban and urban areas, Rural areas occupy the remaining 90 percent. The U. S. Census Bureau, the USDAs Economic Research Service, an urbanized area consists of a central surrounding areas whose population is greater than 50,000. USDA The USDAs Office of Rural Development may define rural by various population thresholds, for example, a metropolitan county is one that contains an urbanized area, or one that has a twenty-five percent commuter rate to an urbanized area regardless of population. In 2014, the USDA updated their rural / non-rural area definitions based on the 2010 Census counts, Rural health definitions can be different for establishing under-served areas or health care accessibility in rural areas of the United States. This became the Goldsmith Modification definition of rural, health care delivery in rural areas of the United States can be challenging. From 2005-2011, the rate of potentially preventable hospitalizations for acute conditions was highest in rural areas, in Brazil, theres different notions of rural area and countryside. Rural areas are any place outside an urban development and its carried by informal usage. Otherwise, countryside are officially defined as all municipalities outside the capitals metropolitan region. Some states as Mato Grosso do Sul doesnt have any metropolitan region, thus all of the state, Rio de Janeiro is singular in Brazil and its de facto a metropolitan state, as circa 70% of its population are located in Greater Rio
10.
Traffic
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Traffic on roads may consist of pedestrians, ridden or herded animals, vehicles, streetcars, buses and other conveyances, either singly or together, while using the public way for purposes of travel. Organized traffic generally has well-established priorities, lanes, right-of-way, Traffic is formally organized in many jurisdictions, with marked lanes, junctions, intersections, interchanges, traffic signals, or signs. Traffic is often classified by type, heavy vehicle, other vehicle. Different classes may share speed limits and easement, or may be segregated, some jurisdictions may have very detailed and complex rules of the road while others rely more on drivers common sense and willingness to cooperate. Organization typically produces a combination of travel safety and efficiency. Events which disrupt the flow and may cause traffic to degenerate into a disorganized mess include road construction, collisions, on particularly busy freeways, a minor disruption may persist in a phenomenon known as traffic waves. A complete breakdown of organization may result in traffic congestion and gridlock, simulations of organized traffic frequently involve queuing theory, stochastic processes and equations of mathematical physics applied to traffic flow. The word traffic originally meant trade and comes from the Old Italian verb trafficare, the origin of the Italian words is unclear. Rules of the road and driving etiquette are the practices and procedures that road users are required to follow. These rules usually apply to all users, though they are of special importance to motorists and cyclists. These rules govern interactions between vehicles and with pedestrians, the basic traffic rules are defined by an international treaty under the authority of the United Nations, the 1968 Vienna Convention on Road Traffic. Not all countries are signatory to the convention and, even among signatories, there are also unwritten local rules of the road, which are generally understood by local drivers. These rules should be distinguished from the procedures required to operate ones vehicle. Traffic going in opposite directions should be separated in such a way that they do not block each others way, the most basic rule is whether to use the left or right side of the road. In many countries, the rules of the road are codified, in the United Kingdom, the rules are set out in the Highway Code, which includes obligations but also advice on how to drive sensibly and safely. In the United States, traffic laws are regulated by the states and municipalities through their respective traffic codes, most of these are based at least in part on the Uniform Vehicle Code, but there are variations from state to state. However, states such as South Carolina have completely criminalized their traffic law, so, for example, vehicles often come into conflict with other vehicles and pedestrians because their intended courses of travel intersect, and thus interfere with each others routes. The general principle that establishes who has the right to go first is called right of way and it establishes who has the right to use the conflicting part of the road and who has to wait until the other does so
11.
Concrete
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Concrete is a composite material composed of coarse aggregate bonded together with a fluid cement that hardens over time. Most concretes used are lime-based concretes such as Portland cement concrete or concretes made with other hydraulic cements, when aggregate is mixed together with dry Portland cement and water, the mixture forms a fluid slurry that is easily poured and molded into shape. The cement reacts chemically with the water and other ingredients to form a matrix that binds the materials together into a durable stone-like material that has many uses. Often, additives are included in the mixture to improve the properties of the wet mix or the finished material. Most concrete is poured with reinforcing materials embedded to provide tensile strength, famous concrete structures include the Hoover Dam, the Panama Canal, and the Roman Pantheon. The earliest large-scale users of technology were the ancient Romans. The Colosseum in Rome was built largely of concrete, and the dome of the Pantheon is the worlds largest unreinforced concrete dome. Today, large concrete structures are made with reinforced concrete. After the Roman Empire collapsed, use of concrete became rare until the technology was redeveloped in the mid-18th century, today, concrete is the most widely used man-made material. The word concrete comes from the Latin word concretus, the passive participle of concrescere, from con-. Perhaps the earliest known occurrence of cement was twelve years ago. A deposit of cement was formed after an occurrence of oil shale located adjacent to a bed of limestone burned due to natural causes and these ancient deposits were investigated in the 1960s and 1970s. On a human timescale, small usages of concrete go back for thousands of years and they discovered the advantages of hydraulic lime, with some self-cementing properties, by 700 BC. They built kilns to supply mortar for the construction of houses, concrete floors. The cisterns were kept secret and were one of the reasons the Nabataea were able to thrive in the desert, some of these structures survive to this day. In the Ancient Egyptian and later Roman eras, it was re-discovered that adding volcanic ash to the mix allowed it to set underwater, similarly, the Romans knew that adding horse hair made concrete less liable to crack while it hardened, and adding blood made it more frost-resistant. Crystallization of strätlingite and the introduction of pyroclastic clays creates further fracture resistance, german archaeologist Heinrich Schliemann found concrete floors, which were made of lime and pebbles, in the royal palace of Tiryns, Greece, which dates roughly to 1400–1200 BC. Lime mortars were used in Greece, Crete, and Cyprus in 800 BC, the Assyrian Jerwan Aqueduct made use of waterproof concrete
12.
Asphalt concrete
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Asphalt concrete is a composite material commonly used to surface roads, parking lots, airports, as well as the core of embankment dams. It consists of mineral aggregate bound together with asphalt, laid in layers, the process was refined and enhanced by Belgian inventor and U. S. immigrant Edward de Smedt. The abbreviation AC is sometimes used for asphalt concrete but can also denote asphalt content or asphalt cement, mixing is generally performed with the aggregate at about 300 °F for virgin asphalt and 330 °F for polymer modified asphalt, and the asphalt cement at 200 °F. Paving and compaction must be performed while the asphalt is sufficiently hot, in many countries paving is restricted to summer months because in winter the compacted base will cool the asphalt too much before it is able to be packed to the required density. HMAC is the form of asphalt concrete most commonly used on high traffic pavements such as those on major highways, racetracks and it is also used as an environmental liner for landfills, reservoirs, and fish hatchery ponds. Superpave, short for superior performing asphalt pavement, is a pavement system designed to provide longer lasting roadways, key components of the system are careful selection of binders and aggregates, volumetric proportioning of ingredients, and evaluation of the finished product. Warm mix asphalt concrete is produced by adding either zeolites, waxes, asphalt emulsions and this allows significantly lower mixing and laying temperatures and results in lower consumption of fossil fuels, thus releasing less carbon dioxide, aerosols and vapors. The usage of additives in hot mixed asphalt may afford easier compaction. Use of warm mix is rapidly expanding, a survey of US asphalt producers found that nearly 25% of asphalt produced in 2012 was warm mix, a 416% increase since 2009. Cold mix asphalt concrete is produced by emulsifying the asphalt in water with soap prior to mixing with the aggregate, while in its emulsified state the asphalt is less viscous and the mixture is easy to work and compact. The emulsion will break after enough water evaporates and the mix will, ideally. Cold mix is used as a patching material and on lesser trafficked service roads. Cut-back asphalt concrete is a form of cold mix asphalt produced by dissolving the binder in kerosene or another lighter fraction of petroleum prior to mixing with the aggregate, while in its dissolved state the asphalt is less viscous and the mix is easy to work and compact. After the mix is laid down the lighter fraction evaporates, because of concerns with pollution from the volatile organic compounds in the lighter fraction, cut-back asphalt has been largely replaced by asphalt emulsion. Mastic asphalt concrete or sheet asphalt is produced by heating hard grade blown bitumen in a green cooker until it has become a liquid after which the aggregate mix is then added. Mastic asphalt concrete is laid to a thickness of around 3⁄4–1 3⁄16 inches for footpath and road applications. HMAC layers are used both in reinforcement operations and in the construction of new reinforcements for medium and heavy traffic, in base layers, they tend to exhibit a greater capacity of absorbing tensions and, in general, better fatigue resistance. In addition to the asphalt and aggregate, additives, such as polymers, Asphalt concrete pavements—especially those at airfields—are sometimes called tarmac for historical reasons, although they do not contain tar and are not constructed using the macadam process
13.
Russia
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Russia, also officially the Russian Federation, is a country in Eurasia. The European western part of the country is more populated and urbanised than the eastern. Russias capital Moscow is one of the largest cities in the world, other urban centers include Saint Petersburg, Novosibirsk, Yekaterinburg, Nizhny Novgorod. Extending across the entirety of Northern Asia and much of Eastern Europe, Russia spans eleven time zones and incorporates a range of environments. It shares maritime borders with Japan by the Sea of Okhotsk, the East Slavs emerged as a recognizable group in Europe between the 3rd and 8th centuries AD. Founded and ruled by a Varangian warrior elite and their descendants, in 988 it adopted Orthodox Christianity from the Byzantine Empire, beginning the synthesis of Byzantine and Slavic cultures that defined Russian culture for the next millennium. Rus ultimately disintegrated into a number of states, most of the Rus lands were overrun by the Mongol invasion. The Soviet Union played a role in the Allied victory in World War II. The Soviet era saw some of the most significant technological achievements of the 20th century, including the worlds first human-made satellite and the launching of the first humans in space. By the end of 1990, the Soviet Union had the second largest economy, largest standing military in the world. It is governed as a federal semi-presidential republic, the Russian economy ranks as the twelfth largest by nominal GDP and sixth largest by purchasing power parity in 2015. Russias extensive mineral and energy resources are the largest such reserves in the world, making it one of the producers of oil. The country is one of the five recognized nuclear weapons states and possesses the largest stockpile of weapons of mass destruction, Russia is a great power as well as a regional power and has been characterised as a potential superpower. The name Russia is derived from Rus, a state populated mostly by the East Slavs. However, this name became more prominent in the later history, and the country typically was called by its inhabitants Русская Земля. In order to distinguish this state from other states derived from it, it is denoted as Kievan Rus by modern historiography, an old Latin version of the name Rus was Ruthenia, mostly applied to the western and southern regions of Rus that were adjacent to Catholic Europe. The current name of the country, Россия, comes from the Byzantine Greek designation of the Kievan Rus, the standard way to refer to citizens of Russia is Russians in English and rossiyane in Russian. There are two Russian words which are translated into English as Russians
14.
Sand
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Sand is a naturally occurring granular material composed of finely divided rock and mineral particles. It is defined by size, being finer than gravel and coarser than silt, Sand can also refer to a textural class of soil or soil type, i. e. a soil containing more than 85% sand-sized particles by mass. The second most common type of sand is calcium carbonate, for example aragonite, for example, it is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years like the Caribbean. Sand is a non renewable resource over human timescales, and sand suitable for making concrete is in high demand, in terms of particle size as used by geologists, sand particles range in diameter from 0.0625 mm to 2 mm. An individual particle in this size is termed a sand grain. Sand grains are between gravel and silt, a 1953 engineering standard published by the American Association of State Highway and Transportation Officials set the minimum sand size at 0.074 mm. A1938 specification of the United States Department of Agriculture was 0.05 mm. Sand feels gritty when rubbed between the fingers. ISO14688 grades sands as fine, medium and coarse with ranges 0.063 mm to 0.2 mm to 0.63 mm to 2.0 mm. In the United States, sand is commonly divided into five sub-categories based on size, very fine sand, fine sand, medium sand, coarse sand, and very coarse sand. These sizes are based on the Krumbein phi scale, where size in Φ = -log2D, on this scale, for sand the value of Φ varies from −1 to +4, with the divisions between sub-categories at whole numbers. The composition of sand is highly variable, depending on the local rock sources. The gypsum sand dunes of the White Sands National Monument in New Mexico are famous for their bright, arkose is a sand or sandstone with considerable feldspar content, derived from weathering and erosion of a granitic rock outcrop. Some sands contain magnetite, chlorite, glauconite or gypsum, Sands rich in magnetite are dark to black in color, as are sands derived from volcanic basalts and obsidian. Chlorite-glauconite bearing sands are typically green in color, as are sands derived from basaltic with a high olivine content, many sands, especially those found extensively in Southern Europe, have iron impurities within the quartz crystals of the sand, giving a deep yellow color. Sand deposits in some areas contain garnets and other resistant minerals, the study of individual grains can reveal much historical information as to the origin and kind of transport of the grain. Quartz sand that is weathered from granite or gneiss quartz crystals will be angular. It is called grus in geology or sharp sand in the trade where it is preferred for concrete. Sand that is transported long distances by water or wind will be rounded, people who collect sand as a hobby are known as arenophiles
15.
Weathering
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Weathering is the breaking down of rocks, soil, and minerals as well as wood and artificial materials through contact with the Earths atmosphere, waters, and biological organisms. Two important classifications of weathering processes exist – physical and chemical weathering, mechanical or physical weathering involves the breakdown of rocks and soils through direct contact with atmospheric conditions, such as heat, water, ice and pressure. While physical weathering is accentuated in very cold or very dry environments, chemical reactions are most intense where the climate is wet, however, both types of weathering occur together, and each tends to accelerate the other. For example, physical abrasion decreases the size of particles and therefore increases their surface area, the various agents act in concert to convert primary minerals to secondary minerals and release plant nutrient elements in soluble forms. The materials left over after the rock breaks down combined with organic material creates soil, in addition, many of Earths landforms and landscapes are the result of weathering processes combined with erosion and re-deposition. Physical weathering, also recognized as mechanical weathering, is the class of processes that causes the disintegration of rocks without chemical change, the primary process in physical weathering is abrasion. However, chemical and physical weathering often go hand in hand, physical weathering can occur due to temperature, pressure, frost etc. For example, cracks exploited by physical weathering will increase the area exposed to chemical action. Abrasion by water, ice, and wind loaded with sediment can have tremendous cutting power, as is amply demonstrated by the gorges, ravines. In glacial areas, huge moving ice masses embedded with soil and rock fragments grind down rocks in their path, plant roots sometimes enter cracks in rocks and pry them apart, resulting in some disintegration, Burrowing animals may help disintegrate rock through their physical action. However, such influences are usually of importance in producing parent material when compared to the drastic physical effects of water, ice, wind. Physical weathering is called mechanical weathering or disaggregation. Thermal stress weathering results from the expansion and contraction of rock, for example, heating of rocks by sunlight or fires can cause expansion of their constituent minerals. As some minerals expand more than others, temperature changes set up differential stresses that cause the rock to crack apart. Because the outer surface of a rock is often warmer or colder than the more protected inner portions and this process may be sharply accelerated if ice forms in the surface cracks. When water freezes, it expands with a force of about 1465 Mg/m^2, disintegrating huge rock masses, thermal stress weathering comprises two main types, thermal shock and thermal fatigue. Thermal stress weathering is an important mechanism in deserts, where there is a diurnal temperature range, hot in the day. The repeated heating and cooling exerts stress on the layers of rocks
16.
Erosion
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In earth science, erosion is the action of surface processes that remove soil, rock, or dissolved material from one location on the Earths crust, then transport it away to another location. Eroded sediment or solutes may be transported just a few millimetres, the rates at which such processes act control how fast a surface is eroded. Feedbacks are also possible between rates of erosion and the amount of eroded material that is carried by, for example. Processes of erosion that produce sediment or solutes from a place contrast with those of deposition, while erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. At well-known agriculture sites such as the Appalachian Mountains, intensive farming practices have caused erosion up to 100x the speed of the rate of erosion in the region. Excessive erosion causes both on-site and off-site problems, on-site impacts include decreases in agricultural productivity and ecological collapse, both because of loss of the nutrient-rich upper soil layers. In some cases, the end result is desertification. Off-site effects include sedimentation of waterways and eutrophication of bodies, as well as sediment-related damage to roads. Intensive agriculture, deforestation, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion, however, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils. Rainfall, and the surface runoff which may result from rainfall, produces four types of soil erosion, splash erosion, sheet erosion, rill erosion. Splash erosion is generally seen as the first and least severe stage in the erosion process. In splash erosion, the impact of a falling raindrop creates a crater in the soil. The distance these soil particles travel can be as much as 0.6 m vertically and 1.5 m horizontally on level ground. If the soil is saturated, or if the rate is greater than the rate at which water can infiltrate into the soil. If the runoff has sufficient flow energy, it will transport loosened soil particles down the slope, sheet erosion is the transport of loosened soil particles by overland flow. Rill erosion refers to the development of small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes, generally, where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are typically of the order of a few centimetres or less and this means that rills exhibit hydraulic physics very different from water flowing through the deeper, wider channels of streams and rivers. Gully erosion occurs when water accumulates and rapidly flows in narrow channels during or immediately after heavy rains or melting snow
17.
Lithified
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Lithification is the process in which sediments compact under pressure, expel connate fluids, and gradually become solid rock. Essentially, lithification is a process of porosity destruction through compaction and cementation, lithification includes all the processes which convert unconsolidated sediments into sedimentary rocks. Petrifaction, though used as a synonym, is more specifically used to describe the replacement of organic material by silica in the formation of fossils
18.
Sedimentary rock
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Sedimentary rocks are types of rock that are formed by the deposition and subsequent cementation of that material at the Earths surface and within bodies of water. Sedimentation is the name for processes that cause mineral and/or organic particles to settle in place. The particles that form a rock by accumulating are called sediment. Sedimentation may also occur as minerals precipitate from solution or shells of aquatic creatures settle out of suspension. The sedimentary rock cover of the continents of the Earths crust is extensive, sedimentary rocks are only a thin veneer over a crust consisting mainly of igneous and metamorphic rocks. Sedimentary rocks are deposited in layers as strata, forming a structure called bedding, sedimentary rocks are also important sources of natural resources like coal, fossil fuels, drinking water or ores. The study of the sequence of rock strata is the main source for an understanding of the Earths history, including palaeogeography, paleoclimatology. The scientific discipline that studies the properties and origin of rocks is called sedimentology. Sedimentology is part of both geology and physical geography and overlaps partly with other disciplines in the Earth sciences, such as pedology, geomorphology, geochemistry, sedimentary rocks have also been found on Mars. Clastic sedimentary rocks are composed of rock fragments that were cemented by silicate minerals. Clastic rocks are composed largely of quartz, feldspar, rock fragments, clay minerals, and mica, any type of mineral may be present, clastic sedimentary rocks, are subdivided according to the dominant particle size. Most geologists use the Udden-Wentworth grain size scale and divide unconsolidated sediment into three fractions, gravel, sand, and mud and this tripartite subdivision is mirrored by the broad categories of rudites, arenites, and lutites, respectively, in older literature. The subdivision of these three categories is based on differences in clast shape, conglomerates and breccias), composition. Conglomerates are dominantly composed of rounded gravel, while breccias are composed of dominantly angular gravel, composition of framework grains The relative abundance of sand-sized framework grains determines the first word in a sandstone name. Naming depends on the dominance of the three most abundant components quartz, feldspar, or the lithic fragments that originated from other rocks, all other minerals are considered accessories and not used in the naming of the rock, regardless of abundance. Clean sandstones with open space are called arenites. Muddy sandstones with abundant muddy matrix are called wackes, six sandstone names are possible using the descriptors for grain composition and the amount of matrix. Mudrocks are sedimentary rocks composed of at least 50% silt- and clay-sized particles and these relatively fine-grained particles are commonly transported by turbulent flow in water or air, and deposited as the flow calms and the particles settle out of suspension
19.
Conglomerate (geology)
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Conglomerates form by the consolidation and lithification of gravel. The size and composition of the fraction of a conglomerate may or may not vary in composition, sorting. In some conglomerates, the gravel-size class consist almost entirely of what were clay clasts at the time of deposition, conglomerates can be found in sedimentary rock sequences of all ages but probably make up less than 1 percent by weight of all sedimentary rocks. A sedimentary rock composed largely of gravel is first named according to the roundness of the gravel, if the gravel clasts that comprise it is largely well-rounded to subrounded, it is a conglomerate. If the gravel clasts that comprise it are largely angular, it is a breccia, such breccias can be called sedimentary breccias to differentiate them from other types of breccia, e. g. volcanic and fault breccias. Sedimentary rocks that contain a mixture of rounded and angular gravel clasts are sometimes called breccio-conglomerate, conglomerates are rarely composed entirely of gravel-size clasts. Typically, the space between the gravel-size clasts is filled by a mixture composed of varying amounts of silt, sand, paraconglomerates are also often unstratified and can contain more matrix than gravel clasts. If the gravel clasts of a conglomerate are in contact with each other, unlike paraconglomerates, orthoconglomerates are typically cross-bedded and often well-cemented and lithified by either calcite, hematite, quartz, or clay. The differences between paraconglomerates and orthoconglomerates reflect differences in how they are deposited, paraconglomerates are commonly either glacial tills or debris flow deposits. Orthoconglomerates are typically associated with aqueous currents, conglomerates are also classified according to the composition of their clasts. A conglomerate or any clastic sedimentary rock that consists of a rock or mineral is known as either a monomict, monomictic, oligomict. If the conglomerate consists of two or more different types of rocks, minerals, or combination of both, it is known as either a polymict or polymictic conglomerate. If a polymictic conglomerate contains an assortment of the clasts of metastable and unstable rocks and minerals, two recognized types of type of intraformational conglomerates are shale-pebble and flat-pebble conglomerates. Finally, conglomerates are often differentiated and named according to the dominant clast size comprising them, conglomerates are deposited in a variety of sedimentary environments. In turbidites, the part of a bed is typically coarse-grained. In this setting, conglomerates are normally very well sorted, well-rounded, conglomerates are normally present at the base of sequences laid down during marine transgressions above an unconformity, and are known as basal conglomerates. They represent the position of the shoreline at a time and are diachronous. Conglomerates deposited in environments are typically well rounded and well sorted
20.
Ice age
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An ice age is a period of long-term reduction in the temperature of Earths surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Within a long-term ice age, individual pulses of cold climate are termed glacial periods, in the terminology of glaciology, ice age implies the presence of extensive ice sheets in both northern and southern hemispheres. In 1742 Pierre Martel, an engineer and geographer living in Geneva, two years later he published an account of his journey. He reported that the inhabitants of that valley attributed the dispersal of erratic boulders to the glaciers, later similar explanations were reported from other regions of the Alps. In 1815 the carpenter and chamois hunter Jean-Pierre Perraudin explained erratic boulders in the Val de Bagnes in the Swiss canton of Valais as being due to glaciers previously extending further. An unknown woodcutter from Meiringen in the Bernese Oberland advocated a similar idea in a discussion with the Swiss-German geologist Jean de Charpentier in 1834, comparable explanations are also known from the Val de Ferret in the Valais and the Seeland in western Switzerland and in Goethes scientific work. Such explanations could also be found in parts of the world. When the Bavarian naturalist Ernst von Bibra visited the Chilean Andes in 1849–1850, meanwhile, European scholars had begun to wonder what had caused the dispersal of erratic material. From the middle of the 18th century, some discussed ice as a means of transport, the Swedish mining expert Daniel Tilas was, in 1742, the first person to suggest drifting sea ice in order to explain the presence of erratic boulders in the Scandinavian and Baltic regions. In 1795, the Scottish philosopher and gentleman naturalist, James Hutton, two decades later, in 1818, the Swedish botanist Göran Wahlenberg published his theory of a glaciation of the Scandinavian peninsula. He regarded glaciation as a regional phenomenon, only a few years later, the Danish-Norwegian geologist Jens Esmark argued a sequence of worldwide ice ages. In a paper published in 1824, Esmark proposed changes in climate as the cause of those glaciations and he attempted to show that they originated from changes in Earths orbit. During the following years, Esmarks ideas were discussed and taken over in parts by Swedish, Scottish, at the University of Edinburgh Robert Jameson seemed to be relatively open to Esmarks ideas, as reviewed by Norwegian professor of glaciology Bjørn G. Andersen. Jamesons remarks about ancient glaciers in Scotland were most probably prompted by Esmark, in Germany, Albrecht Reinhard Bernhardi, a geologist and professor of forestry at an academy in Dreissigacker, since incorporated in the southern Thuringian city of Meiningen, adopted Esmarks theory. In a paper published in 1832, Bernhardi speculated about former polar ice caps reaching as far as the zones of the globe. When he read his paper before the Schweizerische Naturforschende Gesellschaft, most scientists remained sceptical, finally, Venetz convinced his friend Jean de Charpentier. De Charpentier transformed Venetzs idea into a theory with a limited to the Alps. In fact, both men shared the same volcanistic, or in de Charpentiers case rather plutonistic assumptions, about the Earths history, in 1834, de Charpentier presented his paper before the Schweizerische Naturforschende Gesellschaft
21.
Breton language
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Breton /ˈbrɛtən/ is a Southwestern Brittonic Celtic language spoken in Brittany. Breton is most closely related to Cornish, both being Southwestern Brittonic languages, Welsh and the extinct Cumbric are the more distantly related Brittonic languages. The other regional language of Brittany, Gallo, is a langue doïl, Gallo is consequently close to French, although not mutually intelligible, and a Romance language descended from Latin. However, the number of children attending bilingual classes has risen 33% between 2006 and 2012 to 14,709, Breton is spoken in West Brittany, roughly to the west of a line linking Plouha and La Roche-Bernard. It comes from a Brittonic language community that extended from Great Britain to Armorica and had even established a toehold in Galicia. Old Breton is attested from the 9th century and it was the language of the upper classes until the 12th century, after which it became the language of commoners in Lower Brittany. The nobility, followed by the bourgeoisie, adopted French, the written language of the Duchy of Brittany was Latin, switching to French in the 15th century. There exists a tradition of Breton literature. Some Old Breton vocabulary remains in the present day as philosophical, during the French Revolution, the government introduced policies favouring French over the regional languages, which it pejoratively referred to as patois. The revolutionaries assumed that reactionary and monarchist forces preferred regional languages to try to keep the peasant masses underinformed, in 1794, Bertrand Barère submitted his report on the patois to the Committee of Public Safety in which he said that federalism and superstition speak Breton. Teachers humiliated students for using their regional languages, and such practices prevailed until the late 1960s, the majority of todays speakers are more than 60 years old, and Breton is now classified as an endangered language. At the beginning of the 20th century, half of the population of Lower Brittany knew only Breton, by 1950, there were only 100,000 monolingual Bretons, and this rapid decline has continued, with likely no monolingual speakers left today. A statistical survey in 1997 found around 300,000 speakers in Lower Brittany, few 15- to 19-year-olds spoke Breton. In 1925, Professor Roparz Hemon founded the Breton-language review Gwalarn, during its 19-year run, Gwalarn tried to raise the language to the level of a great international language. Its publication encouraged the creation of literature in all genres. In 1946, Al Liamm replaced Gwalarn, other Breton-language periodicals have been published, which established a fairly large body of literature for a minority language. In 1977, Diwan schools were founded to teach Breton by immersion and they taught a few thousand young people from elementary school to high school. See the education section for more information, the Asterix comic series has been translated into Breton
22.
Old French
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Old French was the Gallo-Romance dialect continuum spoken from the 9th century to the 14th century. In the 14th century, these came to be collectively known as the langues doïl. The mid-14th century is taken as the period to Middle French. The areal of Old French in contemporary terms corresponded to the parts of the Kingdom of France, Upper Burgundy. As part of the emerging Gallo-Romance dialect continuum, the langues doïl were contrasted with the langue doc, in these examples, we notice a clear consequence of bilingualism, that sometimes even changed the first syllable of the Latin words. Pope estimated that perhaps still 15% of the vocabulary of modern French derives from Germanic sources, at the third Council of Tours in 813, priests were ordered to preach in the vernacular language, since the common people could no longer understand formal Latin. The second-oldest document in Old French is the Eulalia sequence, which is important for reconstruction of Old French pronunciation due to its consistent spelling. The Capetians langue doïl, the forerunner of modern standard French, did not begin to become the common speech of all of France, however, until after the French Revolution. In the Late Middle Ages, the Old French dialects diverged into a number of distinct langues doïl, during the Early Modern period, French now becomes established as the official language of the Kingdom of France throughout the realm, also including the langue doc-speaking territories in the south. Old French gives way to Middle French in the mid-14th century, the earliest extant French literary texts date from the ninth century, but very few texts before the 11th century have survived. The first literary works written in Old French were saints lives, the Canticle of Saint Eulalie, written in the second half of the 9th century, is generally accepted as the first such text. The first of these is the area of the chansons de geste. More than one hundred chansons de geste have survived in three hundred manuscripts. The oldest and most celebrated of the chansons de geste is The Song of Roland, a fourth grouping, not listed by Bertrand, is the Crusade cycle, dealing with the First Crusade and its immediate aftermath. Jean Bodels other two categories—the Matter of Rome and the Matter of Britain—concern the French romance or roman, around a hundred verse romances survive from the period 1150–1220. From around 1200 on, the tendency was increasingly to write the romances in prose, the most important romance of the 13th century is the Romance of the Rose which breaks considerably from the conventions of the chivalric adventure story. The Occitan or Provençal poets were called troubadours, from the word trobar to find, lyric poets in Old French are called trouvères. By the late 13th century, the tradition in France had begun to develop in ways that differed significantly from the troubadour poets
23.
Crushed stone
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Crushed stone or angular rock is a form of construction aggregate, typically produced by mining a suitable rock deposit and breaking the removed rock down to the desired size using crushers. It is distinct from gravel which is produced by processes of weathering and erosion. Angular crushed stone is the key material for road construction which depends on the interlocking of the individual stones angular faces for its strength. Crushed natural stone is used similarly without a binder for riprap, railroad track ballast. It may also be used with a binder in a material such as concrete, tarmac. Crushed stone is one of the most accessible resources, and is a major basic raw material used by construction, agriculture. Despite the low value of its products, the crushed stone industry is a major contributor to. The demand for crushed stone is determined mostly by the level of activity, and, therefore. Stone resources of the world are very large, high-purity limestone and dolomite suitable for specialty uses are limited in many geographic areas. Crushed stone substitutes for roadbuilding include sand and gravel, and slag, substitutes for crushed stone used as construction aggregates include sand and gravel, iron and steel slag, sintered or expanded clay or shale, and perlite or vermiculite. Crushed stone is a high-volume, low-value commodity, the industry is highly competitive and is characterized by many operations serving local or regional markets. Production costs are determined mainly by the cost of labor, equipment, energy and these costs vary depending on geographic location, the nature of the deposit, and the number and type of products produced. Crushed stone has one of the lowest average by weight values of all mineral commodities, the average unit price increased from US$1.58 per metric ton, f. o. b. plant, in 1970 to US$4.39 in 1990. However, the price in constant 1982 dollars fluctuated between US$3.48 and US$3.91 per metric ton for the same period. Increased productivity achieved through increased use of automation and more efficient equipment was mainly responsible for maintaining the prices at this level, transportation is a major factor in the delivered price of crushed stone. The cost of moving crushed stone from the plant to the market often equals or exceeds the price of the product at the plant. Because of the high cost of transportation and the quantities of bulk material that have to be shipped, crushed stone is usually marketed locally. The high cost of transportation is responsible for the dispersion of quarries
24.
Brandenburg
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Brandenburg is one of the sixteen federated states of Germany. It lies in the northeast of the country covering an area of 29,478 square kilometers and has 2.48 million inhabitants, the capital and largest city is Potsdam. Brandenburg surrounds but does not include the capital and city-state Berlin forming a metropolitan area. Brandenburg is one of the states that was re-created in 1990 upon the reunification of the former East Germany. Governed by the Hohenzollern dynasty from 1415, it contained the future German capital Berlin, after 1618 the Margraviate of Brandenburg and the Duchy of Prussia were combined to form Brandenburg-Prussia, which was ruled by the same branch of the House of Hohenzollern. In 1701 the state was elevated as the Kingdom of Prussia, Brandenburg is situated in territory known in antiquity as Magna Germania, which reached to the Vistula river. By the 7th century, Slavic peoples are believed to have settled in the Brandenburg area, the Slavs expanded from the east, possibly driven from their homelands in present-day Ukraine and perhaps Belarus by the invasions of the Huns and Avars. They relied heavily on river transport, the two principal Slavic groups in the present-day area of Brandenburg were the Hevelli in the west and the Sprevane in the east. Beginning in the early 10th century, Henry the Fowler and his successors conquered territory up to the Oder River, Slavic settlements such as Brenna, Budusin, and Chośebuz came under imperial control through the installation of margraves. Their main function was to defend and protect the eastern marches, in 948 Emperor Otto I established margraves to exert imperial control over the pagan Slavs west of the Oder River. Otto founded the Bishoprics of Brandenburg and Havelberg, the Northern March was founded as a northeastern border territory of the Holy Roman Empire. However, an uprising of Wends drove imperial forces from the territory of present-day Brandenburg in 983. The region returned to the control of Slavic leaders, the Roman Catholic Church brought bishoprics which, with their walled towns, afforded protection from attacks for the townspeople. With the monks and bishops, the history of the town of Brandenburg an der Havel, in 1134, in the wake of a German crusade against the Wends, the German magnate, Albert the Bear, was granted the Northern March by the Emperor Lothar III. He formally inherited the town of Brandenburg and the lands of the Hevelli from their last Wendish ruler, Pribislav, after crushing a force of Sprevane who occupied the town of Brandenburg in the 1150s, Albert proclaimed himself ruler of the new Margraviate of Brandenburg. Albert, and his descendants the Ascanians, then made progress in conquering, colonizing, Christianizing. Within this region, Slavic and German residents intermarried, during the 13th century, the Ascanians began acquiring territory east of the Oder, later known as the Neumark. In 1320, the Brandenburg Ascanian line came to an end, under the Luxembourgs, the Margrave of Brandenburg gained the status of a prince-elector of the Holy Roman Empire
25.
Clay
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Clay is a fine-grained natural rock or soil material that combines one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure. Clays are plastic due to water content and become hard, brittle. Depending on the content in which it is found, clay can appear in various colours from white to dull grey or brown to deep orange-red. Although many naturally occurring deposits include both silts and clay, clays are distinguished from other fine-grained soils by differences in size, silts, which are fine-grained soils that do not include clay minerals, tend to have larger particle sizes than clays. There is, however, some overlap in size and other physical properties. The distinction between silt and clay varies by discipline, geologists and soil scientists usually consider the separation to occur at a particle size of 2 µm, sedimentologists often use 4–5 μm, and colloid chemists use 1 μm. Geotechnical engineers distinguish between silts and clays based on the plasticity properties of the soil, as measured by the soils Atterberg limits, ISO14688 grades clay particles as being smaller than 2 μm and silt particles as being larger. These solvents, usually acidic, migrate through the rock after leaching through upper weathered layers. In addition to the process, some clay minerals are formed through hydrothermal activity. There are two types of deposits, primary and secondary. Primary clays form as residual deposits in soil and remain at the site of formation, secondary clays are clays that have been transported from their original location by water erosion and deposited in a new sedimentary deposit. Clay deposits are associated with very low energy depositional environments such as large lakes. Depending on the source, there are three or four main groups of clays, kaolinite, montmorillonite-smectite, illite, and chlorite. Chlorites are not always considered to be a clay, sometimes being classified as a group within the phyllosilicates. There are approximately 30 different types of clays in these categories. Varve is clay with visible annual layers, which are formed by deposition of those layers and are marked by differences in erosion. This type of deposit is common in glacial lakes
26.
Stream bed
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A stream bed is the channel bottom of a stream, river or creek, the physical confine of the normal water flow. The lateral confines or channel margins are known as the banks or river banks, during all. Under certain conditions a river can branch from one bed to multiple stream beds. A flood occurs when a stream overflows its banks and flows onto its flood plain, as a general rule, the bed is the part of the channel up to the normal water line, and the banks are that part above the normal water line. However, because water flow varies, this differentiation is subject to local interpretation, the nature of any stream bed is always a function of the flow dynamics and the local geologic materials, influenced by that flow. With small streams in mesophytic regions, the nature of the bed is strongly responsive to conditions of precipitation runoff. Where natural conditions of either grassland or forest ameliorate peak flows, stream beds are stable, possibly rich, with organic matter and these streams support a rich biota. Where conditions produce unnatural levels of runoff, such as occurs below roads and this process greatly increases watershed erosion and results in thinner soils, upslope from the stream bed, as the channel adjusts to the increase in flow. The stream bed is very complex in terms of erosion, sediment is transported, eroded and deposited on the stream bed. With global warming there is a fear that the size and shape of riverbeds will change due to increased flood magnitude and this shows that the stream bed is left mostly unchanged in size and shape. Dry stream beds are also subject to becoming underground water pockets and flooding by heavy rains and water rising from the ground and may sometimes be part of the rejuvenation of the stream
27.
Tar
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Tar is a black mixture of hydrocarbons and free carbon obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat, production and trade in pine-derived tar was a major contributor in the economies of Northern Europe and Colonial America. Its main use was in preserving wooden vessels against rot, the largest user was the Royal Navy. Demand for tar declined with the advent of iron and steel ships, tar-like products can also be produced from other forms of organic matter, such as peat. Mineral products resembling tar can be produced from hydrocarbons, such as petroleum. Coal tar is produced from coal as a byproduct of coke production, Bitumen is a term used for natural deposits of oil tar, such as at the La Brea Tar Pits. In Northern Europe, the word tar refers primarily to a substance that is derived from the wood, in earlier times it was often used as a water repellent coating for boats, ships, and roofs. It is still used as an additive in the flavoring of candy, alcohol, producing tar from wood was known in ancient Greece and has probably been used in Scandinavia since the Iron Age. For centuries, dating back at least to the 14th century, sweden exported 13,000 barrels of tar in 1615 and 227,000 barrels in the peak year of 1863. Production nearly stopped in the early 20th century, when other chemicals replaced tar, traditional wooden boats are still sometimes tarred. The heating of wood causes tar and pitch to drip away from the wood. Birch bark is used to make particularly fine tar, known as Russian oil, the by-products of wood tar are turpentine and charcoal. When deciduous tree woods are subjected to distillation, the products are methanol. Tar kilns are dry distillation ovens, historically used in Scandinavia for producing tar from wood and they were built close to the forest, from limestone or from more primitive holes in the ground. The bottom is sloped into a hole to allow the tar to pour out. The wood is split into dimensions of a finger, stacked densely, if oxygen can enter, the wood might catch fire, and the production would be ruined. On top of this, a fire is stacked and lit, after a few hours, the tar starts to pour out and continues to do so for a few days. Tar was used as seal for roofing shingles and tar paper and to seal the hulls of ships, for millennia, wood tar was used to waterproof sails and boats, but today, sails made from inherently waterproof synthetic substances have reduced the demand for tar
28.
Granite
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Granite is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. Granites can be white, pink, or gray in color. The word granite comes from the Latin granum, a grain, in reference to the structure of such a holocrystalline rock. By definition, granite is a rock with at least 20% quartz. The term granitic means granite-like and is applied to granite and a group of igneous rocks with similar textures and slight variations in composition. Occasionally some individual crystals are larger than the groundmass, in case the texture is known as porphyritic. A granitic rock with a texture is known as a granite porphyry. Granitoid is a general, descriptive field term for lighter-colored, coarse-grained igneous rocks, petrographic examination is required for identification of specific types of granitoids. The extrusive igneous rock equivalent of granite is rhyolite, Granite is nearly always massive, hard and tough, and therefore it has gained widespread use throughout human history, and more recently as a construction stone. The average density of granite is between 2.65 and 2.75 g/cm3, its compressive strength usually lies above 200 MPa, and its viscosity near STP is 3–6 •1019 Pa·s. The melting temperature of dry granite at ambient pressure is 1215–1260 °C, it is reduced in the presence of water. Granite has poor primary permeability, but strong secondary permeability, true granite according to modern petrologic convention contains both plagioclase and alkali feldspars. When a granitoid is devoid or nearly devoid of plagioclase, the rock is referred to as alkali feldspar granite, when a granitoid contains less than 10% orthoclase, it is called tonalite, pyroxene and amphibole are common in tonalite. A granite containing both muscovite and biotite micas is called a binary or two-mica granite, two-mica granites are typically high in potassium and low in plagioclase, and are usually S-type granites or A-type granites. A worldwide average of the composition of granite, by weight percent, based on 2485 analyses. Much of it was intruded during the Precambrian age, it is the most abundant basement rock that underlies the relatively thin veneer of the continents. Outcrops of granite tend to form tors and rounded massifs, granites sometimes occur in circular depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels. Granite often occurs as small, less than 100 km² stock masses
29.
Limestone
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Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral, forams and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate, about 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, most cave systems are through limestone bedrock. The first geologist to distinguish limestone from dolomite was Belsazar Hacquet in 1778, like most other sedimentary rocks, most limestone is composed of grains. Most grains in limestone are skeletal fragments of organisms such as coral or foraminifera. Other carbonate grains comprising limestones are ooids, peloids, intraclasts and these organisms secrete shells made of aragonite or calcite, and leave these shells behind when they die. Limestone often contains variable amounts of silica in the form of chert or siliceous skeletal fragment, some limestones do not consist of grains at all, and are formed completely by the chemical precipitation of calcite or aragonite, i. e. travertine. Secondary calcite may be deposited by supersaturated meteoric waters and this produces speleothems, such as stalagmites and stalactites. Another form taken by calcite is oolitic limestone, which can be recognized by its granular appearance, the primary source of the calcite in limestone is most commonly marine organisms. Some of these organisms can construct mounds of rock known as reefs, below about 3,000 meters, water pressure and temperature conditions cause the dissolution of calcite to increase nonlinearly, so limestone typically does not form in deeper waters. Limestones may also form in lacustrine and evaporite depositional environments, calcite can be dissolved or precipitated by groundwater, depending on several factors, including the water temperature, pH, and dissolved ion concentrations. Calcite exhibits a characteristic called retrograde solubility, in which it becomes less soluble in water as the temperature increases. Impurities will cause limestones to exhibit different colors, especially with weathered surfaces, Limestone may be crystalline, clastic, granular, or massive, depending on the method of formation. Crystals of calcite, quartz, dolomite or barite may line small cavities in the rock, when conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together, or it can fill fractures. Travertine is a banded, compact variety of limestone formed along streams, particularly there are waterfalls. Calcium carbonate is deposited where evaporation of the leaves a solution supersaturated with the chemical constituents of calcite. Tufa, a porous or cellular variety of travertine, is found near waterfalls, coquina is a poorly consolidated limestone composed of pieces of coral or shells. During regional metamorphism that occurs during the building process, limestone recrystallizes into marble
30.
Dolostone
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Dolostone or dolomite rock is a sedimentary carbonate rock that contains a high percentage of the mineral dolomite, CaMg2. In old USGS publications it was referred to as magnesian limestone, technically, dolostone has a stoichiometric ratio of nearly equal amounts of magnesium and calcium. Most dolostones formed as a replacement of limestone or lime mud prior to lithification. It is resistant to erosion and can either contain bedded layers or be unbedded and it is less soluble than limestone in weakly acidic groundwater, but it can still develop solution features over time. Dolostone can act as an oil and natural gas reservoir, the term dolostone was introduced to avoid confusion with the mineral dolomite. The usage of the term dolostone is controversial because the name dolomite was first applied to the rock during the late 18th century, the use of the term dolostone is not recommended by the Glossary of Geology published by the American Geological Institute. It is, however, used in some geological publications, the geological process of conversion of calcite to dolomite is known as dolomitization and any intermediate product is known as dolomitic limestone. The dolomite problem refers to the vast worldwide depositions of dolostone in past geologic record eluding a unified explanation for their formation, as with limestone caves, natural caves and solution tubes can form in dolomite rock as a result of dissolution by weak carbonic acid. Calcium carbonate speleothems in the forms of stalactites, stalagmites, flowstone etc, “Dolomite is a common rock type, but a relatively uncommon mineral in speleothems”. Both calcium and magnesium go into solution when dolomite rock is dissolved, the speleothem precipitation sequence is, calcite, Mg-calcite, aragonite, huntite and hydromagnesite. Hence, the most common speleothem in caves within dolomite rock karst, is calcium carbonate in the most stable form of calcite. Speleothem types known to have a dolomite constituent include, coatings, crusts, moonmilk, flowstone, coralloids, powder, spar and rafts. Although there are reports of dolomite speleothems known to exist in a number of cave around the world, they are usually in small quantities. Blatt, Harvey, Tracy, Robert J. Petrology, Igneous, Sedimentary, tucker, M. E. V. P. Wright. Zenger, D. H. Mazzullo, S. J. Dolomitization
31.
Gold panning
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Gold panning, or simply panning, is a form of placer mining and traditional mining that extracts gold from a placer deposit using a pan. The process is one of the simplest ways to extract gold, and is popular with geology enthusiasts especially because of its cheap cost and the relatively simple and easy process. The first recorded instances of mining are from ancient Rome. Gold panning is a simple process, once a suitable placer deposit is located, some alluvial deposit are scooped into a pan, where it is then gently agitated in water and the gold sinks to the bottom of the pan. These dense materials usually consist primarily of a black, magnetite sand with stones or metal dust that may be found in the deposit that is used for source material. Pans remain in use in places there is limited capital or infrastructure. In many situations, gold panning usually turns up only minor gold dust that is collected as a souvenir in small clear tubes by hobbyists. Nuggets and considerable amounts of dust are found, but panning mining is not generally lucrative. Panning for gold can be used to locate the parent gold veins which are the source of most placer deposits, some are intended for use with mercury, include screens, sharp corners for breaking ice, are non-round, or are even designed for use with or without water. Edward Otho Cresap Ord, II, a former Army officer and co-owner of several mines, pans are measured by their diameter in inches or centimeters. Common sizes of gold pans today range between 10–17 inches, with 14 inches being the most used size, the sides are generally angled between 30° to 45°. Pans are manufactured in metal and high-impact plastic. Russia iron or heavy gauge steel pans are traditional, steel pans are heavier and stronger than plastic pans. Some are made of alloys for structural stability. Plastic gold pans resist rust, acid and corrosion, and most are designed with moulded riffles along one side of the pan, the batea is a particular variant of gold pan. Traditionally made of a piece of wood, it may also be made of metal. Bateas are used in areas where there is water available for use than with traditional gold pans, such as Mexico and South America. Bateas are larger than other gold pans, being closer to half a meter in diameter, the yuri-ita, Japanese for rocking plate is a traditional wooden gold pan used in Japan
32.
Construction aggregate
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Aggregates are the most mined materials in the world. Aggregates are a component of composite materials such as concrete and asphalt concrete, aggregates are also used as base material under foundations, roads, and railroads. Preferred bitumenous aggregate sizes for road construction are given in EN13043 as d/D, the same classification sizing is used for larger armour stone sizes in EN13383, EN12620 for concrete aggregate, EN13242 for base layers of road construction and EN13450 for railway ballast. These products include specific types of coarse and fine aggregate designed for such uses as additives to asphalt and concrete mixes, state transportation departments further refine aggregate material specifications in order to tailor aggregate use to the needs and available supply in their particular locations. In addition, there are materials that are used as specialty lightweight aggregates, clay, pumice, perlite. People have used sand and stone for foundations for thousands of years, significant refinement of the production and use of aggregate occurred during the Roman Empire, which used aggregate to build its vast network of roads and aqueducts. The invention of concrete, which was essential to architecture utilizing arches, created an immediate, vitruvius writes in De architectura, Economy denotes the proper management of materials and of site, as well as a thrifty balancing of cost and common sense in the construction of works. This will be observed if, in the first place, the architect does not demand things which cannot be found or made ready without great expense, for example, it is not everywhere that there is plenty of pit-sand, rubble, fir, clear fir, and marble. Where there is no pit sand, we must use the kinds washed up by rivers or by the sea. the advent of modern blasting methods enabled the development of quarries, which are now used throughout the world, wherever competent bedrock deposits of aggregate quality exist. In many places, good limestone, granite, marble or other quality stone bedrock deposits do not exist, in these areas, natural sand and gravel are mined for use as aggregate. Where neither stone, nor sand and gravel, are available, construction demand is satisfied by shipping in aggregate by rail. Additionally, demand for aggregates can be satisfied through the use of slag. However, the available tonnages and lesser quality of these materials prevent them from being a replacement for mined aggregates on a large scale. Large stone quarry and sand and gravel operations exist near virtually all population centers, limestone and granite are also produced in large amounts as dimension stone. The great majority of crushed stone is moved by truck from the quarry/plant to the first point of sale or use. According to the USGS,2006 U. S. sand and gravel production was 1.32 billion tonnes valued at $8.54 billion, the great majority of this was again moved by truck, instead of by electric train. Currently, total U. S. aggregate demand by final market sector was 30%–35% for non-residential building, 25% for highways, the largest-volume of recycled material used as construction aggregate is blast furnace and steel furnace slag. Blast furnace slag is either air-cooled or granulated, if the granulated blast furnace slag accesses free lime during hydration, it develops strong hydraulic cementitious properties and can partly substitute for portland cement in concrete
33.
Rock (geology)
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Rock or stone is a natural substance, a solid aggregate of one or more minerals or mineraloids. For example, granite, a rock, is a combination of the minerals quartz, feldspar. The Earths outer solid layer, the lithosphere, is made of rock, rock has been used by mankind throughout history. The minerals and metals found in rocks have been essential to human civilization, three major groups of rocks are defined, igneous, sedimentary, and metamorphic. The scientific study of rocks is called petrology, which is a component of geology. At a granular level, rocks are composed of grains of minerals, the aggregate minerals forming the rock are held together by chemical bonds. The types and abundance of minerals in a rock are determined by the manner in which the rock was formed, many rocks contain silica, a compound of silicon and oxygen that forms 74. 3% of the Earths crust. This material forms crystals with other compounds in the rock, the proportion of silica in rocks and minerals is a major factor in determining their name and properties. Rocks are geologically classified according to such as mineral and chemical composition, permeability, the texture of the constituent particles. These physical properties are the end result of the processes that formed the rocks, over the course of time, rocks can transform from one type into another, as described by the geological model called the rock cycle. These events produce three general classes of rock, igneous, sedimentary, and metamorphic, the three classes of rocks are subdivided into many groups. However, there are no hard and fast boundaries between allied rocks, hence the definitions adopted in establishing rock nomenclature merely correspond to more or less arbitrary selected points in a continuously graduated series. Igneous rock forms through the cooling and solidification of magma or lava and this magma can be derived from partial melts of pre-existing rocks in either a planets mantle or crust. Typically, the melting of rocks is caused by one or more of three processes, an increase in temperature, a decrease in pressure, or a change in composition, igneous rocks are divided into two main categories, plutonic rock and volcanic. Plutonic or intrusive rocks result when magma cools and crystallizes slowly within the Earths crust, a common example of this type is granite. Volcanic or extrusive rocks result from magma reaching the surface either as lava or fragmental ejecta, the chemical abundance and the rate of cooling of magma typically forms a sequence known as Bowens reaction series. Most major igneous rocks are found along this scale, about 64. 7% of the Earths crust by volume consists of igneous rocks, making it the most plentiful category. Of these, 66% are basalts and gabbros, 16% are granite, only 0. 6% are syenites and 0. 3% peridotites and dunites
34.
Wayback Machine
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The Internet Archive launched the Wayback Machine in October 2001. It was set up by Brewster Kahle and Bruce Gilliat, and is maintained with content from Alexa Internet, the service enables users to see archived versions of web pages across time, which the archive calls a three dimensional index. Since 1996, the Wayback Machine has been archiving cached pages of websites onto its large cluster of Linux nodes and it revisits sites every few weeks or months and archives a new version. Sites can also be captured on the fly by visitors who enter the sites URL into a search box, the intent is to capture and archive content that otherwise would be lost whenever a site is changed or closed down. The overall vision of the machines creators is to archive the entire Internet, the name Wayback Machine was chosen as a reference to the WABAC machine, a time-traveling device used by the characters Mr. Peabody and Sherman in The Rocky and Bullwinkle Show, an animated cartoon. These crawlers also respect the robots exclusion standard for websites whose owners opt for them not to appear in search results or be cached, to overcome inconsistencies in partially cached websites, Archive-It. Information had been kept on digital tape for five years, with Kahle occasionally allowing researchers, when the archive reached its fifth anniversary, it was unveiled and opened to the public in a ceremony at the University of California, Berkeley. Snapshots usually become more than six months after they are archived or, in some cases, even later. The frequency of snapshots is variable, so not all tracked website updates are recorded, Sometimes there are intervals of several weeks or years between snapshots. After August 2008 sites had to be listed on the Open Directory in order to be included. As of 2009, the Wayback Machine contained approximately three petabytes of data and was growing at a rate of 100 terabytes each month, the growth rate reported in 2003 was 12 terabytes/month, the data is stored on PetaBox rack systems manufactured by Capricorn Technologies. In 2009, the Internet Archive migrated its customized storage architecture to Sun Open Storage, in 2011 a new, improved version of the Wayback Machine, with an updated interface and fresher index of archived content, was made available for public testing. The index driving the classic Wayback Machine only has a bit of material past 2008. In January 2013, the company announced a ground-breaking milestone of 240 billion URLs, in October 2013, the company announced the Save a Page feature which allows any Internet user to archive the contents of a URL. This became a threat of abuse by the service for hosting malicious binaries, as of December 2014, the Wayback Machine contained almost nine petabytes of data and was growing at a rate of about 20 terabytes each week. Between October 2013 and March 2015 the websites global Alexa rank changed from 162 to 208, in a 2009 case, Netbula, LLC v. Chordiant Software Inc. defendant Chordiant filed a motion to compel Netbula to disable the robots. Netbula objected to the motion on the ground that defendants were asking to alter Netbulas website, in an October 2004 case, Telewizja Polska USA, Inc. v. Echostar Satellite, No.02 C3293,65 Fed. 673, a litigant attempted to use the Wayback Machine archives as a source of admissible evidence, Telewizja Polska is the provider of TVP Polonia and EchoStar operates the Dish Network
35.
Geotechnical engineering
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Geotechnical engineering is the branch of civil engineering concerned with the engineering behavior of earth materials. A typical geotechnical engineering project begins with a review of project needs to define the material properties. Site investigations are needed to gain an understanding of the area in or on which the engineering will take place, a geotechnical engineer then determines and designs the type of foundations, earthworks, and/or pavement subgrades required for the intended man-made structures to be built. Foundations built for above-ground structures include shallow and deep foundations, retaining structures include earth-filled dams and retaining walls. Earthworks include embankments, tunnels, dikes and levees, channels, reservoirs, deposition of hazardous waste, Geotechnical engineering is also related to coastal and ocean engineering. Coastal engineering can involve the design and construction of wharves, marinas, ocean engineering can involve foundation and anchor systems for offshore structures such as oil platforms. The fields of engineering and engineering geology are closely related. However, the field of engineering is a specialty of engineering. Humans have historically used soil as a material for flood control, irrigation purposes, burial sites, building foundations, as the cities expanded, structures were erected supported by formalized foundations, Ancient Greeks notably constructed pad footings and strip-and-raft foundations. Until the 18th century, however, no basis for soil design had been developed. Several foundation-related engineering problems, such as the Leaning Tower of Pisa, the earliest advances occurred in the development of earth pressure theories for the construction of retaining walls. Henri Gautier, a French Royal Engineer, recognized the natural slope of different soils in 1717, a rudimentary soil classification system was also developed based on a materials unit weight, which is no longer considered a good indication of soil type. The application of the principles of mechanics to soils was documented as early as 1773 when Charles Coulomb developed improved methods to determine the pressures against military ramparts. By combining Coulombs theory with Christian Otto Mohrs 2D stress state, although it is now recognized that precise determination of cohesion is impossible because c is not a fundamental soil property, the Mohr-Coulomb theory is still used in practice today. In the 19th century Henry Darcy developed what is now known as Darcys Law describing the flow of fluids in porous media, albert Atterberg developed the clay consistency indices that are still used today for soil classification. Osborne Reynolds recognized in 1885 that shearing causes volumetric dilation of dense, modern geotechnical engineering is said to have begun in 1925 with the publication of Erdbaumechanik by Karl Terzaghi. Terzaghi also developed the framework for theories of bearing capacity of foundations, in his 1948 book, Donald Taylor recognized that interlocking and dilation of densely packed particles contributed to the peak strength of a soil. Critical state soil mechanics is the basis for many contemporary advanced constitutive models describing the behavior of soil, Geotechnical centrifuge modeling is a method of testing physical scale models of geotechnical problems
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Geotechnical investigation
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This type of investigation is called a site investigation. A geotechnical investigation will include surface exploration and subsurface exploration of a site, sometimes, geophysical methods are used to obtain data about sites. Subsurface exploration usually involves soil sampling and laboratory tests of the soil samples retrieved, to obtain information about the soil conditions below the surface, some form of subsurface exploration is required. Methods of observing the soils below the surface, obtaining samples, and determining physical properties of the soils and rocks include test pits, trenching, boring, borings come in two main varieties, large-diameter and small-diameter. Small-diameter borings are frequently used to allow a geologist or engineer to examine soil or rock cuttings or to samples at depth using soil samplers. Soil samples are often categorized as being disturbed or undisturbed, however. Offshore soil collection introduces many difficult variables, in shallow water, work can be done off a barge. In deeper water a ship will be required, deepwater soil samplers are normally variants of Kullenberg-type samplers, a modification on a basic gravity corer using a piston. Seabed samplers are available, which push the collection tube slowly into the soil. Soil samples are taken using a variety of samplers, some provide only disturbed samples, samples can be obtained by digging out soil from the site. Samples taken this way are disturbed samples, trial Pits are relatively small hand or machine excavated tranches used to determine groundwater levels and take disturbed samples from. This sampler typically consists of a cylinder with a cutting edge attached to a rod. The sampler is advanced by a combination of rotation and downward force, samples taken this way are disturbed samples. A method of sampling using an auger as a corkscrew, the auger is screwed into the ground then lifted out. Soil is retained on the blades of the auger and kept for testing, the soil sampled this way is considered disturbed. Utilized in the Standard Test Method for Standard Penetration Test and Split-Barrel Sampling of Soils and this sampler is typically an 18-30 long,2.0 outside diameter hollow tube split in half lengthwise. A hardened metal drive shoe with a 1.375 opening is attached to the end. It is driven into the ground with a 140-pound hammer falling 30, the blow counts required to advance the sampler a total of 18 are counted and reported
37.
Cone penetration test
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The cone penetration or cone penetrometer test is a method used to determine the geotechnical engineering properties of soils and delineating soil stratigraphy. It was initially developed in the 1950s at the Dutch Laboratory for Soil Mechanics in Delft to investigate soft soils, based on this history it has also been called the Dutch cone test. Today, the CPT is one of the most used and accepted methods for soil investigation worldwide. The test method consists of pushing an instrumented cone, with the tip facing down, the early applications of CPT mainly determined the soil geotechnical property of bearing capacity. The original cone penetrometers involved simple mechanical measurements of the total resistance to pushing a tool with a conical tip into the soil. Different methods were employed to separate the total measured resistance into components generated by the conical tip, a friction sleeve was added to quantify this component of the friction and aid in determining soil cohesive strength in the 1960s. Electronic measurements began in 1948 and improved further in the early 1970s, most modern electronic CPT cones now also employ a pressure transducer with a filter to gather pore water pressure data. The filter is located either on the cone tip, immediately behind the cone tip or behind the friction sleeve. Pore water pressure data aids determining stratigraphy and is used to correct tip friction values for those effects. CPT testing which also gathers this data is called CPTU testing. CPT and CPTU testing equipment generally advances the cone using hydraulic rams mounted on either a heavily ballasted vehicle or using screwed-in anchors as a counter-force. One advantage of CPT over the Standard Penetration Test is a continuous profile of soil parameters, with data recorded at intervals typically of 20 cm. In addition to the mechanical and electronic cones, a variety of other CPT-deployed tools have developed over the years to provide additional subsurface information. One common tool advanced during CPT testing is a set to gather seismic shear wave. This data helps determine the shear modulus and Poissons ratio at intervals through the column for soil liquefaction analysis. Engineers use the wave velocity and shear modulus to determine the soils behavior under low-strain. An additional CPT deployed tool used in Britain, Netherlands, Germany, Belgium and this is used to attempt to ensure that tests, boreholes, and piles, do not encounter unexploded ordnance or duds. The magnetometer in the cone detects ferrous materials of 50 kg or larger within a radius of up to about 2 m distance from the probe depending on the material, orientation, CPT for geotechnical applications was standardized in 1986 by ASTM Standard D3441
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Standard penetration test
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The standard penetration test is an in-situ dynamic penetration test designed to provide information on the geotechnical engineering properties of soil. The test procedure is described in ISO 22476-3, ASTM D1586, the test uses a thick-walled sample tube, with an outside diameter of 50.8 mm and an inside diameter of 35 mm, and a length of around 650 mm. This is driven into the ground at the bottom of a borehole by blows from a hammer with a mass of 63.5 kg falling through a distance of 760 mm. The sample tube is driven 150 mm into the ground and then the number of blows needed for the tube to penetrate each 150 mm up to a depth of 450 mm is recorded. The sum of the number of blows required for the second, in cases where 50 blows are insufficient to advance it through a 150 mm interval the penetration after 50 blows is recorded. The blow count provides an indication of the density of the ground, detailed procedure can be found on Geotechdata. info database. The main purpose of the test is to provide an indication of the density of granular deposits, such as sands. The great merit of the test, and the reason for its widespread use is that it is simple. If the samples are found to be disturbed, it may be necessary to use a different method for measuring strength like the plate test. When the test is carried out in granular soils below groundwater level, in certain circumstances, it can be useful to continue driving the sampler beyond the distance specified, adding further drilling rods as necessary. Soils in arid areas, such as the Western United States and this condition will often increase the standard penetration value. The SPT is used to provide results for empirical determination of a sand layers susceptibility to soil liquefaction, based on research performed by Harry Seed, despite its many flaws, it is usual practice to correlate SPT results with soil properties relevant for geotechnical engineering design. Standard Penetration Test blow counts do not represent a physical property of the soil. There exist multiple correlations, none of which are of high quality
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Water well
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A water well is an excavation or structure created in the ground by digging, driving, boring, or drilling to access groundwater in underground aquifers. The well water is drawn by a pump, or using containers, such as buckets, placing a lining in the well shaft helps create stability and linings of wood or wickerwork date back at least as far as the Iron Age. Wells have been sunk by hand digging as is the case in rural developing areas. These wells are inexpensive and low-tech as they use mostly manual labour, a more modern method called caissoning uses pre-cast reinforced concrete well rings that are lowered into the hole. Deeper wells can be excavated by hand drilling methods or machine drilling, using a bit in a borehole, drilled wells are usually cased with a factory-made pipe composed of steel or plastic. Drilled wells can access water at greater depths than dug wells. A collector well can be constructed adjacent to a lake or stream with water percolating through the intervening material. The site of a well can be selected by a hydrogeologist, Water may be pumped or hand drawn. Impurities from the surface can easily reach shallow sources and contamination of the supply by pathogens or chemical contaminants needs to be avoided, Well water typically contains more minerals in solution than surface water and may require treatment before being potable. Soil salination can occur as the water falls and the surrounding soil begins to dry out. Another environmental problem is the potential for methane to seep into the water, hand-dug wells are excavations with diameters large enough to accommodate one or more people with shovels digging down to below the water table. The excavation is braced horizontally to avoid landslide or erosion endangering the people digging, a more modern method called caissoning uses reinforced concrete or plain concrete pre-cast well rings that are lowered into the hole. A well-digging team digs under a ring and the well column slowly sinks into the aquifer. Hand-dug wells are inexpensive and low tech as they use mostly manual labour to access groundwater in rural locations in developing countries and they may be built with a high degree of community participation, or by local entrepreneurs who specialize in hand-dug wells. They have been excavated to 60 metres. They have low operational and maintenance costs, in part because water can be extracted by hand bailing, without a pump. The water is coming from an aquifer or groundwater, and can be easily deepened. The yield of existing hand dug wells may be improved by deepening or introducing vertical tunnels or perforated pipes, drawbacks to hand-dug wells are numerous
40.
Piezometer
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A piezometer is designed to measure static pressures, and thus differs from a pitot tube by not being pointed into the fluid flow. Observation wells give some information on the level in a formation. Electrical pressure transducers of several types can be read automatically, making data acquisition more convenient, the first piezometers in geotechnical engineering were open wells or standpipes installed into an aquifer. A Casagrande piezometer will typically have a casing down to the depth of interest. The casing is sealed into the drillhole with clay, bentonite or concrete to prevent surface water from contaminating the groundwater supply. In an unconfined aquifer, the level in the piezometer would not be exactly coincident with the water table. In a confined aquifer under artesian conditions, the level in the piezometer indicates the pressure in the aquifer. Piezometer wells can be smaller in diameter than production wells. Piezometers in durable casings can be buried or pushed into the ground to measure the pressure at the point of installation. The pressure gauges can be vibrating-wire, pneumatic, or strain-gauge in operation, converting pressure into an electrical signal
41.
Borehole
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A borehole is a narrow shaft bored in the ground, either vertically or horizontally. g. in Carbon capture and storage. This includes holes advanced to collect samples, water samples or rock cores, to advance in situ sampling equipment. Samples collected from boreholes are often tested in a laboratory to determine their physical properties, typically, a borehole used as a water well is completed by installing a vertical pipe and well screen to keep the borehole from caving. This also helps prevent surface contaminants from entering the borehole and protects any installed pump from drawing in sand, oil and natural gas wells are completed in a similar, albeit usually more complex, manner. As detailed in proxy, borehole temperature measurements at a series of different depths can be inverted to help estimate historic surface temperatures. Clusters of small-diameter boreholes equipped with heat exhangers made of plastic PEX pipe can be used to heat or cold between opposing seasons in a mass of native rock. The technique is called seasonal thermal energy storage, media that can be used for this technique range from gravel to bedrock. There can be a few to several hundred boreholes, and in practice, Borehole drilling has a long history. Han Dynasty China used deep borehole drilling for mining and other projects, chinese borehole sites could reach as deep as 600 m. The practice of logging in boreholes dates to 1927, for the French Pechelbronn oil field. For many years, the world’s deepest borehole was the Kola Superdeep Borehole, from 2011 until August 2012 the record was held by the 12, 345-metre long Sakhalin-I Odoptu OP-11 Well, offshore the Russian island Sakhalin. The Chayvo Z-44 extended-reach well took the title of the worlds longest borehole on 27 August 2012, z-44s total measured depth is 12,376 m. However, ERD wells are more shallow than Kola Superdeep Borehole, drillers may sink a borehole using a drilling rig or a hand-operated rig. The machinery and techniques to advance a borehole vary considerably according to manufacturer, geological conditions, for offshore drilling floating units or platforms supported by the seafloor are used for the drilling rig. Askam Borehole in Pennsylvania Borehole thermal energy storage Deep borehole disposal Hole opener Kola Superdeep Borehole Vertical seismic profile
42.
Atterberg limits
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The Atterberg limits are a basic measure of the critical water contents of a fine-grained soil, its shrinkage limit, plastic limit, and liquid limit. As a dry, clayey soil takes on increasing amounts of water, it undergoes changes in behavior. Depending on the content of the soil, it may appear in four states, solid, semi-solid, plastic. In each state, the consistency and behavior of a soil is different, thus, the boundary between each state can be defined based on a change in the soils behavior. The Atterberg limits can be used to distinguish between silt and clay, and it can distinguish different types of silts and clays. These limits were created by Albert Atterberg, a Swedish agriculturist and they were later refined by Arthur Casagrande. These distinctions in soil are used in assessing the soils that are to have built on. Soils when wet retain water and some expand in volume, the amount of expansion is related to the ability of the soil to take in water and its structural make-up. These tests are used on clayey or silty soils since these are the soils that expand. Clays and silts react with the water and thus change sizes and have varying shear strengths, as a hard, rigid solid in the dry state, soil becomes a crumbly semisolid when a certain moisture content, termed the shrinkage limit, is reached. If it is a soil, this soil will also begin to swell in volume as this moisture content is exceeded. Increasing the water content beyond the soils plastic limit will transform it into a malleable, plastic mass, the soil will remain in this plastic state until its liquid limit is exceeded, which causes it to transform into a viscous liquid that flows when jarred. The shrinkage limit is the content where further loss of moisture will not result in any more volume reduction. The test to determine the limit is ASTM International D4943. The shrinkage limit is less commonly used than the liquid. The plastic limit is determined by rolling out a thread of the portion of a soil on a flat. The procedure is defined in ASTM Standard D4318, if the soil is at a moisture content where its behavior is plastic, this thread will retain its shape down to a very narrow diameter. The sample can then be remolded and the test repeated, as the moisture content falls due to evaporation, the thread will begin to break apart at larger diameters
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