1.
Consolidation (soil)
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Consolidation is a process by which soils decrease in volume. According to Karl von Terzaghi consolidation is any process which involves a decrease in water content of saturated soil without replacement of water by air, in general it is the process in which reduction in volume takes place by expulsion of water under long term static loads. It occurs when stress is applied to a soil causes the soil particles to pack together more tightly. When this occurs in a soil that is saturated with water, water will be squeezed out of the soil, the magnitude of consolidation can be predicted by many different methods. In the Classical Method, developed by Terzaghi, soils are tested with an oedometer test to determine their compression index and this can be used to predict the amount of consolidation. When stress is removed from a soil, the soil will rebound. If the stress is reapplied, the soil will consolidate again along a recompression curve, the soil which had its load removed is considered to be overconsolidated. This is the case for soils which have previously had glaciers on them, the highest stress that it has been subjected to is termed the preconsolidation stress. The over consolidation ratio or OCR is defined as the highest stress experienced divided by the current stress, a soil which is currently experiencing its highest stress is said to be normally consolidated and to have an OCR of one. A soil could be considered underconsolidated immediately after a new load is applied, the process of consolidation is often explained with an idealized system composed of a spring, a container with a hole in its cover, and water. In this system, the spring represents the compressibility or the structure of the soil itself, the container is completely filled with water, and the hole is closed. A load is applied onto the cover, while the hole is still unopened, at this stage, only the water resists the applied load. As soon as the hole is opened, water starts to drain out through the hole, after some time, the drainage of water no longer occurs. Now, the spring alone resists the applied load and this method assumes consolidation occurs in only one-dimension. Laboratory data is used to construct a plot of strain or void ratio versus effective stress where the stress axis is on a logarithmic scale. The plots slope is the index or recompression index. The equation for consolidation settlement of a consolidated soil can then be determined to be. E0 is the void ratio
2.
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
3.
Soil
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Soil is a mixture of minerals, organic matter, gases, liquids, and countless organisms that together support life on Earth. Soil is called the Skin of the Earth and interfaces with the lithosphere, the hydrosphere, the atmosphere, the term pedolith, used commonly to refer to the soil, literally translates ground stone. Soil consists of a phase of minerals and organic matter, as well as a porous phase that holds gases. Accordingly, soils are often treated as a system of solids, liquids. Soil is a product of the influence of climate, relief, organisms, Soil continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness soil has been considered as an ecosystem by soil ecologists. Most soils have a dry bulk density between 1.1 and 1.6 g/cm3, while the particle density is much higher. Little of the soil of planet Earth is older than the Pleistocene and none is older than the Cenozoic, Soil science has two basic branches of study, edaphology and pedology. Edaphology is concerned with the influence of soils on living things, pedology is focused on the formation, description, and classification of soils in their natural environment. In engineering terms, soil is referred to as regolith, or loose material that lies above the solid geology. Soil is commonly referred to as earth or dirt, technically, as soil resources serve as a basis for food security, the international community advocates its sustainable and responsible use through different types of soil governance. Soil is a component of the Earths ecosystem. The worlds ecosystems are impacted in far-reaching ways by the carried out in the soil, from ozone depletion and global warming, to rainforest destruction. Following the atmosphere, the soil is the next largest carbon reservoir on Earth, as the planet warms, soils will add carbon dioxide to the atmosphere due to its increased biological activity at higher temperatures. Thus, soil carbon losses likely have a positive feedback response to global warming. Since soil has a range of available niches and habitats. A gram of soil can contain billions of organisms, belonging to thousands of species, mostly microbial, Soil has a mean prokaryotic density of roughly 108 organisms per gram, whereas the ocean has no more than 107 procaryotic organisms per milliliter of seawater. Since plant roots need oxygen, ventilation is an important characteristic of soil and this ventilation can be accomplished via networks of interconnected soil pores, which also absorb and hold rainwater making it readily available for plant uptake
4.
Soil science
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Sometimes terms which refer to branches of soil science, such as pedology and edaphology, are used as if synonymous with soil science. The diversity of names associated with this discipline is related to the various associations concerned, Soil occupies the pedosphere, one of Earths spheres that the geosciences use to organize the Earth conceptually. This is the perspective of pedology and edaphology, the two main branches of soil science. Pedology is the study of soil in its natural setting, edaphology is the study of soil in relation to soil-dependent uses. Both branches apply a combination of physics, soil chemistry. Due to the interactions between the biosphere, atmosphere and hydrosphere that are hosted within the pedosphere, more integrated. Many concepts essential to understanding soil come from individuals not identifiable strictly as soil scientists and this highlights the interdisciplinary nature of soil concepts. Dependence on and curiosity about soil, exploring the diversity and dynamics of this continues to yield fresh discoveries. New avenues of research are compelled by a need to understand soil in the context of climate change, greenhouse gases. Interest in maintaining the biodiversity and in exploring past cultures has also stimulated renewed interest in achieving a more refined understanding of soil. Most empirical knowledge of soil in nature comes from soil survey efforts, Soil survey, or soil mapping, is the process of determining the soil types or other properties of the soil cover over a landscape, and mapping them for others to understand and use. It relies heavily on distinguishing the individual influences of the five classic soil forming factors and this effort draws upon geomorphology, physical geography, and analysis of vegetation and land-use patterns. Primary data for the survey are acquired by field sampling. As of 2006, the World Reference Base for Soil Resources and it replaces the previous FAO soil classification. The WRB borrows from modern soil classification concepts, including USDA soil taxonomy, the classification is based mainly on soil morphology as an expression pedogenesis. A major difference with USDA soil taxonomy is that climate is not part of the system. Many other classification schemes exist, including vernacular systems, the structure in vernacular systems are either nominal, giving unique names to soils or landscapes, or descriptive, naming soils by their characteristics such as red, hot, fat, or sandy. Soils are distinguished by obvious characteristics, such as appearance, performance
5.
Agronomy
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Agronomy is the science and technology of producing and using plants for food, fuel, fiber, and land reclamation. Agronomy has come to work in the areas of plant genetics, plant physiology, meteorology. It is the application of a combination of sciences like biology, chemistry, economics, ecology, earth science, agronomists of today are involved with many issues, including producing food, creating healthier food, managing the environmental impact of agriculture, and extracting energy from plants. Agronomists often specialise in such as crop rotation, irrigation and drainage, plant breeding, plant physiology, soil classification, soil fertility, weed control. This area of agronomy involves selective breeding of plants to produce the best crops under various conditions, plant breeding has increased crop yields and has improved the nutritional value of numerous crops, including corn, soybeans, and wheat. It has also led to the development of new types of plants, for example, a hybrid grain called triticale was produced by crossbreeding rye and wheat. Triticale contains more protein than does either rye or wheat. Agronomy has also been instrumental in fruit and vegetable production research, agronomists use biotechnology to extend and expedite the development of desired characteristic. Biotechnology is often a lab activity requiring field testing of the new varieties that are developed. In addition to increasing crop yields agronomic biotechnology is increasingly being applied for novel uses other than food, for example, oilseed is at present used mainly for margarine and other food oils, but it can be modified to produce fatty acids for detergents, substitute fuels and petrochemicals. Agronomists study sustainable ways to make soils more productive and profitable and they classify soils and analyze them to determine whether they contain nutrients vital to plant growth. Common macronutrients analyzed include compounds of nitrogen, phosphorus, potassium, calcium, magnesium, soil is also assessed for several micronutrients, like zinc and boron. The percentage of organic matter, soil pH, and nutrient holding capacity are tested in a regional laboratory, agronomists will interpret these lab reports and make recommendations to balance soil nutrients for optimal plant growth. In addition, agronomists develop methods to preserve the soil and to decrease the effects of erosion by wind, for example, a technique called contour plowing may be used to prevent soil erosion and conserve rainfall. Researchers in agronomy also seek ways to use the more effectively in solving other problems. Such problems include the disposal of human and animal manure, water pollution, techniques include no-tilling crops, planting of soil-binding grasses along contours on steep slopes, and contour drains of depths up to 1 metre. Agroecology is the management of systems with an emphasis on ecological and environmental perspectives. This area is associated with work in the areas of sustainable agriculture, organic farming, and alternative food systems
6.
Rain
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Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated—that is, become heavy enough to fall under gravity. Rain is a component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystems, as well as water for power plants. The major cause of production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts. If enough moisture and upward motion is present, precipitation falls from convective clouds such as cumulonimbus which can organize into narrow rainbands. On the leeward side of mountains, desert climates can exist due to the dry air caused by downslope flow which causes heating and drying of the air mass, the movement of the monsoon trough, or intertropical convergence zone, brings rainy seasons to savannah climes. The urban heat island effect leads to increased rainfall, both in amounts and intensity, downwind of cities, global warming is also causing changes in the precipitation pattern globally, including wetter conditions across eastern North America and drier conditions in the tropics. The globally averaged annual precipitation over land is 715 mm, climate classification systems such as the Köppen climate classification system use average annual rainfall to help differentiate between differing climate regimes. Rainfall is measured using rain gauges, rainfall amounts can be estimated by weather radar. Rain is also known or suspected on other planets, where it may be composed of methane, neon, sulfuric acid, or even iron rather than water. Air contains water vapor, and the amount of water in a mass of dry air. The amount of moisture in air is commonly reported as relative humidity. How much water vapor a parcel of air can contain before it becomes saturated, warmer air can contain more water vapor than cooler air before becoming saturated. Therefore, one way to saturate a parcel of air is to cool it, the dew point is the temperature to which a parcel must be cooled in order to become saturated. There are four mechanisms for cooling the air to its dew point, adiabatic cooling, conductive cooling, radiational cooling. Adiabatic cooling occurs when air rises and expands, the air can rise due to convection, large-scale atmospheric motions, or a physical barrier such as a mountain. Conductive cooling occurs when the air comes into contact with a surface, usually by being blown from one surface to another. Radiational cooling occurs due to the emission of infrared radiation, either by the air or by the surface underneath, evaporative cooling occurs when moisture is added to the air through evaporation, which forces the air temperature to cool to its wet-bulb temperature, or until it reaches saturation
7.
Surface runoff
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Surface runoff is the flow of water that occurs when excess stormwater, meltwater, or other sources flows over the Earths surface. Surface runoff is a component of the water cycle. It is the agent in soil erosion by water. Runoff that occurs on the surface before reaching a channel is also called a nonpoint source. If a nonpoint source contains man-made contaminants, or natural forms of pollution the runoff is called nonpoint source pollution, a land area which produces runoff that drains to a common point is called a drainage basin. When runoff flows along the ground, it can pick up soil contaminants including petroleum, pesticides, surface runoff can be generated either by rainfall, snowfall or by the melting of snow, or glaciers. Snow and glacier melt occur only in areas cold enough for these to form permanently, typically snowmelt will peak in the spring and glacier melt in the summer, leading to pronounced flow maxima in rivers affected by them. The determining factor of the rate of melting of snow or glaciers is both air temperature and the duration of sunlight, in high mountain regions, streams frequently rise on sunny days and fall on cloudy ones for this reason. In areas where there is no snow, runoff will come from rainfall, however, not all rainfall will produce runoff because storage from soils can absorb light showers. This occurs when the rate of rainfall on a surface exceeds the rate at which water can infiltrate the ground and this is called flooding excess overland flow, Hortonian overland flow, or unsaturated overland flow. This more commonly occurs in arid and semi-arid regions, where rainfall intensities are high and this occurs largely in city areas where pavements prevent water from flooding. When the soil is saturated and the depression storage filled, and rain continues to fall, the level of antecedent soil moisture is one factor affecting the time until soil becomes saturated. This runoff is called saturation excess overland flow or saturated overland flow, soil retains a degree of moisture after a rainfall. This residual water moisture affects the soils infiltration capacity, during the next rainfall event, the infiltration capacity will cause the soil to be saturated at a different rate. The higher the level of antecedent soil moisture, the more quickly the soil becomes saturated, once the soil is saturated, runoff occurs. After water infiltrates the soil on a portion of a hill, the water may flow laterally through the soil. This is called subsurface return flow or throughflow, any remaining surface water eventually flows into a receiving water body such as a river, lake, estuary or ocean. Urbanization increases surface runoff by creating more impervious surfaces such as pavement and it is instead forced directly into streams or storm water runoff drains, where erosion and siltation can be major problems, even when flooding is not
8.
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
9.
Root
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In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. Roots can also be aerial or aerating, that is growing up above the ground or especially above water, furthermore, a stem normally occurring below ground is not exceptional either. Therefore, the root is best defined as the non-leaf, non-nodes bearing parts of the plants body, however, important internal structural differences between stems and roots exist. The fossil record of roots – or rather, infilled voids where roots rotted after death – spans back to the late Silurian and their identification is difficult, because casts and molds of roots are so similar in appearance to animal burrows. They can be discriminated using a range of features, the first root that comes from a plant is called the radicle. In response to the concentration of nutrients, roots also synthesise cytokinin, Roots often function in storage of food and nutrients. The roots of most vascular plant species enter into symbiosis with fungi to form mycorrhizae. In its simplest form, the root architecture refers to the spatial configuration of a plant’s root system. This system can be complex and is dependent upon multiple factors such as the species of the plant itself, the composition of the soil. The configuration of root systems serves to support the plant, compete with other plants. Roots grow to specific conditions, which, if changed, can impede a plants growth. For example, a system that has developed in dry soil may not be as efficient in flooded soil, yet plants are able to adapt to other changes in the environment. Root architecture plays the important role of providing a supply of nutrients and water as well as anchorage. The main terms used to classify the architecture of a system are, Branch magnitude. Root angle, the angle of a lateral root’s base around the parent root’s circumference, the angle of a lateral root from its parent root. Link radius, the diameter of a root, all components of the root architecture are regulated through a complex interaction between genetic responses and responses due to environmental stimuli. These developmental stimuli are categorised as intrinsic, the genetic and nutritional influences, or extrinsic, the main hormones and respective pathways responsible for root architecture development include, Auxin – Auxin promotes root initiation, root emergence and primary root elongation. Cytokinins – Cytokinins regulate root apical meristem size and promote lateral root elongation, gibberellins – Together with ethylene they promote crown primordia growth and elongation
10.
Vertisol
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In both the FAO and USDA soil taxonomy, a vertisol is a soil in which there is a high content of expansive clay known as montmorillonite that forms deep cracks in drier seasons or years. Alternate shrinking and swelling causes self-mulching, where the soil material consistently mixes itself, causing vertisols to have an extremely deep A horizon and this heaving of the underlying material to the surface often creates a microrelief known as gilgai. Vertisols typically form from highly basic rocks, such as basalt, in climates that are humid or subject to erratic droughts and floods. Depending on the parent material and the climate, they can range from grey or red to the familiar deep black. Vertisols are found between 50°N and 45°S of the equator, major areas where vertisols are dominant are eastern Australia, the Deccan Plateau of India, and parts of southern Sudan, Ethiopia, Kenya, and Chad, and the lower Paraná River in South America. Other areas where vertisols are dominant include southern Texas and adjacent Mexico, central India, northeast Nigeria, Thrace, New Caledonia, the natural vegetation of vertisols is grassland, savanna, or grassy woodland. The heavy texture and unstable behaviour of the soil makes it difficult for many species to grow. The shrinking and swelling of vertisols can damage buildings and roads, Vertisols are generally used for grazing of cattle or sheep. It is not unknown for livestock to be injured through falling into cracks in dry periods, conversely, many wild and domestic ungulates do not like to move on this soil when inundated. However, the activity allows rapid recovery from compaction. When irrigation is available, crops such as cotton, wheat, sorghum, Vertisols are especially suitable for rice because they are almost impermeable when saturated. Rainfed farming is difficult because vertisols can be worked only under a very narrow range of moisture conditions. However, in Australia, vertisols are highly regarded, because they are among the few soils that are not acutely deficient in available phosphorus. Some, known as crusty vertisols, have a thin, hard crust when dry that can persist for two to three years before they have crumbled enough to permit seeding. In the USA soil taxonomy, vertisols are subdivided into, Aquerts, Vertisols which are subdued aquic conditions for some time in most years, because of the high clay content, the permeability is slowed down and aquic conditions are likely to occur. In general, when precipitation exceeds evapotranspiration, ponding may occur, under wet soil moisture conditions, iron and manganese are mobilized and reduced. The manganese may be responsible for the dark color of the soil profile. Cryerts, They have a soil temperature regime
11.
Earthworm
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An earthworm is a tube-shaped, segmented worm found in the phylum Annelida. Earthworms are commonly found living in soil, feeding on live, an earthworms digestive system runs through the length of its body. It conducts respiration through its skin and it has a double transport system composed of coelomic fluid that moves within the fluid-filled coelom and a simple, closed blood circulatory system. It has a central and a nervous system. The central nervous system consists of two ganglia above the mouth, one on side, connected to a nerve cord running back along its length to motor neurons. Large numbers of chemoreceptors are concentrated near its mouth, circumferential and longitudinal muscles on the periphery of each segment enable the worm to move. Similar sets of line the gut, and their actions move the digesting food toward the worms anus. Earthworms are hermaphrodites–each individual carries both male and female sex organs and they lack either an internal skeleton or exoskeleton, but maintain their structure with fluid-filled coelom chambers that function as a hydrostatic skeleton. Earthworm is the name for the largest members of Oligochaeta. In classical systems, they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, theoretical cladistic studies have placed them, instead, in the suborder Lumbricina of the order Haplotaxida, but this may again soon change. Folk names for the earthworm include dew-worm, rainworm, night crawler, larger terrestrial earthworms are also called megadriles, as opposed to the microdriles in the semiaquatic families Tubificidae, Lumbricidae, and Enchytraeidae, among others. The megadriles are characterized by having a clitellum and a vascular system with true capillaries. Earthworms are far less abundant in disturbed environments and are active only if water is present. Depending on the species, an adult earthworm can be from 10 mm long and 1 mm wide to 3 m long and over 25 mm wide, but the typical Lumbricus terrestris grows to about 360 mm long. From front to back, the shape of the earthworm is a cylindrical tube. Special ventral setae are used to anchor mating earthworms by their penetration into the bodies of their mates, generally, within a species, the number of segments found is consistent across specimens, and individuals are born with the number of segments they will have throughout their lives. Some species of earthworm can even use the prehensile prostomium to grab, an adult earthworm develops a belt-like glandular swelling, called the clitellum, which covers several segments toward the front part of the animal. This is part of the system and produces egg capsules
12.
Cecil (soil)
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Originally mapped in Cecil County, Maryland in 1899, more than 10 million acres of the Cecil soil series are now mapped in the Piedmont region of the southeastern United States. The subsoil is a red clay which is dominated by kaolinite and has considerable mica, few Cecil soils are in their virgin state, for most have been cultivated at one time or another. Indifferent land management has allowed many areas of Cecil soils to lose their topsoils through soil erosion and this clay is amenable to cultivation, responds well to careful management, and supports good growth of pine where allowed to revert to forest. Like other well-drained Ultisols, it is ideal for development, however, in common with other kaolinite-dominated clays. Total potassium in the Cecil is higher than typical for Ultisols due to the presence of mica, ap—0 to 8 inches, dark yellowish brown sandy loam, weak medium granular structure, very friable, slightly acid, abrupt smooth boundary. 2 inches to 8 inches thick, bt1—8 to 26 inches, red clay, moderate medium subangular blocky structure, firm, sticky, plastic, common clay films on faces of peds, few fine flakes of mica, strongly acid, gradual wavy boundary. BC—42 to 50 inches, red loam, few distinct yellowish red mottles, weak medium subangular blocky structure, friable, few fine flakes of mica, very strongly acid. C--50 to 80 inches, red loam saprolite, common medium distinct pale yellow and common distinct brown mottles, massive, very friable, few fine flakes of mica, very strongly acid. Pedology List of U. S. state soils Official Series Description - Cecil Series Cecil soil landscape near Columbus GA
13.
Backhoe
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A backhoe, also called a rear actor or back actor, is a piece of excavating equipment or digger consisting of a digging bucket on the end of a two-part articulated arm. They are typically mounted on the back of a tractor or front loader, the section of the arm closest to the vehicle is known as the boom, and the section which carries the bucket is known as the dipper or dipper-stick, terms derived from steam shovels). The boom is attached to the vehicle through a pivot known as the king-post. Confusingly, the buckets on some backhoes may be reconfigured facing forward, however they are not as effective in that orientation, since the dimensions of the various components are optimized for backhoeing. Most backhoes are at their strongest curling the bucket, with the arm next most powerful. A backhoe loader is a vehicle with a backhoe at one end, a front loader on the other. In North America, this arrangement is referred to as simply a backhoe or, when on a chassis originally derived from farm tractors. To differentiate, a backhoe on its own dedicated chassis may then be referred to as an excavator, Backhoe loaders can be designed and manufactured from the start as such, or can be the result of a farm tractor equipped with a front end loader and rear backhoe. Though similar looking, the purpose-designed backhoe loaders are much stronger, many backhoes feature quick coupler mounting systems for simplified attachment mounting, dramatically increasing the machines utilization on the job site. Backhoes are usually employed together with loaders and bulldozers, Excavators that use a backhoe are sometimes called trackhoes by people who do not realize the name is due to the action of the bucket, not its location on a backhoe loader. On many job sites which would have seen a backhoe used, a skidsteer. However, backhoes still are in general use, sometimes a backhoe bucket is reversed to work in a power shovel configuration. This is generally when loading from a stockpile, for picking up or filling material next to walls, to increase the reach of the machine. Sometimes a backhoe arm is used as a crane, by slinging the lifted object from the support linkages behind the scoop, the backhoes scoop may have a metal bar called a thumb hinged to the scoop. It grips against the scoop like a thumb to pick up objects. Some types can lie back against the arm when not needed. Early development of systems for what would become the backhoe loader proceeded in parallel in the US. In July 1948, patent #2,698,697 was filed by Vaino J. Holopainen, the swing frame breakthrough allowed the hydraulic digging arm to swing to the side to dump the bucket
14.
Compactor
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A compactor is a machine or mechanism used to reduce the size of material such as waste material or bio mass through compaction. A trash compactor is used by a home or business to reduce the amount of trash. A baler-wrapper compactor is used for making compact and wrapped bales in order to improve logistics. Normally powered by hydraulics, compactors take many shapes and sizes, in landfill sites for example, a large tractor with spiked steel wheels called a landfill compactor is used to drive over waste deposited by waste collection vehicles. WCVs themselves incorporate a mechanism which is used to increase the payload of the vehicle. This usually takes the form of hydraulically powered sliding plates which sweep out the collection hopper, different compactors are used in scrap metal processing, the most familiar being the car crusher. Many retail and service businesses, such as fast food, restaurants, in the hospitality industry tolerance for such nuisances is particularly low. These compactors typically come in electric and hydraulic operation, with quite a few loading configurations, most popular loading configurations fall under the following, Ground-access, Walk-on, Secured indoor chute. As a means to preserve and store forage, baler-wrapper compactors are used to exclude oxygen from the forage, without access to air the forage is preserved fresh for longer periods of time. There are also trash compactors, hydraulic or manual, designed for residential use, likewise, they reduce the volume of garbage. For example, some compactors reduce the volume of polystyrene to 1/30, in addition to the waste vehicle and landfill use, there are solar-powered trash compactors that can hold the equivalent of 200 gallons of trash before they need to be emptied. Baler-wrapper compactors are used for efficient storage and transport of materials like RDF and bin waste, as well as compost and saw dust, in construction, there are three main types of compactor, the plate, the jumping jack and the road roller. The roller type compactors are used for compacting crushed rock as the layer underneath concrete or stone foundations or slabs. The plate compactor has a large vibrating baseplate and is suited for creating a level grade, the jumping jack type is mainly used to compact the backfill in narrow trenches for water or gas supply pipes etc. Road rollers may also have vibrating rollers, in England the name wacker plate or just wacker is commonly used to refer to plate compactors, derived from the name of Wacker Neuson, a well-known manufacturer of such devices. The name is pronounced in the English style as whacker as opposed to the correct German vacker, patent 2,234,098 — Can crusher and baler —1941 U. S. S. National Institute for Occupational Safety and Health
15.
Road roller
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A road roller is a compactor type engineering vehicle used to compact soil, gravel, concrete, or asphalt in the construction of roads and foundations. Similar rollers are used also at landfills or in agriculture, in some parts of the world, road rollers are still known colloquially as steam rollers, regardless of their method of propulsion. This typically only applies to the largest examples, the first road rollers were horse-drawn, and were probably just borrowed farm implements. Since the effectiveness of a roller depends to an extent on its weight. The first such vehicles were steam rollers, some road companies in the United States used steamrollers through the 1950s, and in the UK, some remained in commercial service until the early 1970s. As internal combustion engine technology improved during the 20th century, kerosene-, gasoline-, the first internal-combustion powered road rollers were very similar to the steam rollers they replaced. They used similar mechanisms to transmit power from the engine to the wheels, typically large, some users did not like them in their infancy, as the engines of the era were typically difficult to start, particularly the kerosene-powered ones. Virtually all road rollers in commercial use now use diesel power, road rollers use the weight of the vehicle to compress the surface being rolled or use mechanical advantage. Initial compaction of the substrate on a project is done using a padfoot drum roller. On regional roads a smaller single padfoot drum machine may be used, sometimes at this stage a pneumatic tyre roller would be used. Once the soil base is flat the pad drum compactor is no longer used on the road surface, once the road base is compacted, the smooth single drum compactor is no longer used on the road surface. The final wear course of concrete is laid using a paver and compacted using a tandem smooth drum roller. Rollers are also used in landfill compaction, such compactors typically have padfoot or sheeps-foot drums, and do not achieve a smooth surface. The pads aid in compression, due to the area contacting the ground. The roller can be a drum with a handle that is operated by one person. A landfill unit may weigh 59 short tons, rammer Walk-behind plate compactor/light Trench roller Walk-behind roller/light Walk-behind roller/heavy Tandem drum Tandem drum Single drum roller Pneumatic-tyred Roller, a. k. a. Tyre rollers are available in widths ranging up to 2.7 metres, with between 7 and 11 wheels,7 and 8 wheel types are used in Europe and Africa,9 and 11 in America. Very heavy tyre rollers are used to compact soil, on some machines, the drums may be filled with water on site to achieve the desired weight
16.
Hamm AG
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Hamm AG is a German worldwide manufacturer and marketer of road rollers based in Tirschenreuth, Germany. It is a subsidiary of Wirtgen Group, brothers Anton and Franz Hamm, who were gunsmiths, founded the company in 1878 to build agricultural equipment. The company built their first diesel-powered road roller in 1911, from a design by a second-generation Hamm and this was at a time when most rollers where steam powered. In 1928 the company abandoned all other lines to concentrate on road rollers. In 1999 the Wirtgen Group GmbH announced that it would purchase Hamm AG, Hamm AG Hamm AG Hamm America Hamm India
17.
Wacker Neuson
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Founded in 1848, the family-owned company now has more than 50 affiliates, over 140 sales and service stations and over 12,000 sales and service partners worldwide. The Group has currently 4,632 employees, Wacker Neuson SE has been listed on the SDAX since 2007. The company was founded in 1848 by Johann Christian Wacker as a shop in Dresden trading as Wacker. It started industrial production in 1875, in 1930, the company’s engineers developed a high-frequency technology for internal vibrators. At the same time, the first electrically powered rammer – an innovation in concrete, before the start of World War II, the company had already expanded its product portfolio and created a domestic and international sales and retail organization. Progress was halted by the destruction of the facility in Dresden just before the end of the war. Business operations were resumed in Kulmbach in 1945, and the company moved its headquarters to Munich in 1951, the first foreign affiliate was established in 1957 in Hartford. In 1986, Hartford operations relocated to Menomonee Falls, now home to a production facility, subsequently, the company stepped up its international presence, and now has 50 affiliates, over 140 sales and service outlets and over 12,000 sales and service partners worldwide. The group changed structure from a company to a public limited company, Wacker Construction Equipment AG. Until 2005, Wacker only developed, produced and distributed light construction equipment up to approx, three tonnes in the concrete technology, soil & asphalt compaction, demolition and utility segments. Following the acquisition of Weidemann GmbH in 2005, the company branched out into construction equipment. Drillfix AG and Ground Heaters, Inc. were purchased in 2006, the company was floated on 15 May 2007, and is listed in the Prime Standard of the Frankfurt Stock Exchange. It was admitted to the SDAX in autumn 2007, Neuson Kramer Baumaschinen AG itself was the product of a merger between Neuson Baumaschinen GmbH and the long-established company Kramer-Werke GmbH. Neuson was established in 1981 as Neuson Hydraulik GmbH, based in Linz, Neuson Baumaschinen GmbH was established in 1990. Dumper manufacturer Lifton Ltd. was acquired in 1998, and skid-steer loaders were added to the range in 2004. Neuson and Kramer merged in 2001, in February 2009, Wacker Construction Equipment AG underwent a change of legal form and assumed its current name of Wacker Neuson SE. Wacker Neuson SE organises its activities by region, the group is divided into three business fields, Light Equipment, Compact Equipment, and Services. The Compact Equipment segment supplies excavators, wheel loaders, telescopic handlers and these machines are used in application areas including structural and civil engineering, road construction, agriculture, gardening, landscaping, municipal works, recycling and industrial projects
18.
Rut (roads)
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A rut is a depression or groove worn into a road or path by the travel of wheels or skis. Ruts can be formed by wear, as from studded snow tires common in cold climate areas, rut-like depressions can be formed on gravel roads by the erosion from flowing water. Ruts prevent rainwater from flowing to the side of the road into ditches or gutters, rainwater trapped in ruts is a common contributing factor to hydroplaning crashes. Severe ruts can impede steering if a vehicle has difficulty steering out of the rut, if it proves impossible to steer out of a rut, though forward and backward progress can be made by the vehicle, it is referred to as being stuck in the rut. Ruts in gravel roads can be removed by grading the road surface, if the ruts are formed due to deformation of the subbase below the pavement, the only long-term repair is usually full-depth reconstruction of the road. Typically rutting is reported in terms of rut depth, rutting is measured at highway speeds with a laser/inertial profilograph. The term stuck in a rut can be used figuratively to refer to a situation in which, as time progresses, the ancient Assyrians, Babylonians, Persians and Greeks constructed roads with artificial wheel-ruts deliberately cut into rock. The ruts were spaced apart from each other the same distance as the wheelspan of an ordinary carriage, such ancient stone rutways connected major cities with sacred sites, such as Athens to Eleusis, Sparta to Ayklia, or Elis to Olympia. The gauge of these stone grooves was 1.38 to 1.44 m, the largest number of preserved stone trackways, over 150, are found on Malta. Some of these ancient stone rutways were very ambitious, around 600 BC the citizens of ancient Corinth constructed the Diolkos, which some consider the worlds first railway. The Diolkos was a hard poros limestone road with grooved tracks, along which large wooden flatbed cars carrying entire ships, the grooves were at 1.67 m centres. The argument is that this is shown by the evidence of rutted roads marked by cart wheels dating from the Roman Empire, snopes categorized this legend as false but commented that. It is perhaps more fairly labelled as True, but for trivial, the historical tendency to place the wheels of horse-drawn vehicles approximately 5 feet apart probably derives from the width needed to fit a carthorse in between the shafts. Ruts are also deeper at the entry to and exit from intersections and corners, due to deceleration and acceleration
19.
Soil type
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In terms of soil texture, soil type usually refers to the different sizes of mineral particles in a particular sample. Soil is made up in part of finely ground rock particles, grouped according to size as sand and silt in addition to clay, each component, and their size, play an important role. The ratio of these sizes determines soil type, clay, loam, clay-loam, silt-loam, in addition to the mineral composition of soil, humus also plays an important role in soil characteristics and fertility for plant life. Soil may be mixed with larger aggregate, such as pebbles or gravel, not all types of soil are permeable, such as pure clay. There are many recognized soil classifications, both international and national, category, Types of soil Soil classification systems A Compendium of On-Line Soil Survey Information Soil Classification for Soil Survey OSHA Soil Classification -1926 Subpart P App A soil types
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Silt
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Silt is granular material of a size between sand and clay, whose mineral origin is quartz and feldspar. Silt may occur as a soil or as sediment mixed in suspension with water in a body of such as a river. It may also exist as soil deposited at the bottom of a water body, Silt has a moderate specific area with a typically non-sticky, plastic feel. Silt usually has a floury feel when dry, and a slippery feel when wet, Silt can be visually observed with a hand lens. Silt is created by a variety of physical processes capable of splitting the generally sand-sized quartz crystals of primary rocks by exploiting deficiencies in their lattice and these involve chemical weathering of rock and regolith, and a number of physical weathering processes such as frost shattering and haloclasty. The main process is abrasion through transport, including fluvial comminution, aeolian attrition and it is in semi-arid environments that substantial quantities of silt are produced. Silt is sometimes known as rock flour or stone dust, especially produced by glacial action. Mineralogically, silt is composed mainly of quartz and feldspar, sedimentary rock composed mainly of silt is known as siltstone. Liquefaction created by an earthquake is silt suspended in water that is hydrodynamically forced up from below ground level. In the Udden–Wentworth scale, silt particles range between 0.0039 and 0.0625 mm, larger than clay but smaller than sand particles, ISO14688 grades silts between 0.002 mm and 0.063 mm. In actuality, silt is chemically distinct from clay, and unlike clay, grains of silt are approximately the size in all dimensions, furthermore. Clays are formed from thin plate-shaped particles held together by electrostatic forces, according to the U. S. Department of Agriculture Soil Texture Classification system, the sand-silt distinction is made at the 0.05 mm particle size. The USDA system has been adopted by the Food and Agriculture Organization, in the Unified Soil Classification System and the AASHTO Soil Classification system, the sand-silt distinction is made at the 0.075 mm particle size. Silts and clays are distinguished mechanically by their plasticity, Silt is easily transported in water or other liquid and is fine enough to be carried long distances by air in the form of dust. Thick deposits of silty material resulting from deposition by aeolian processes are called loess. Silt and clay contribute to turbidity in water, Silt is transported by streams or by water currents in the ocean. When silt appears as a pollutant in water the phenomenon is known as siltation, Silt, deposited by annual floods along the Nile River, created the rich, fertile soil that sustained the Ancient Egyptian civilization. In south east Bangladesh, in the Noakhali district, cross dams were built in the 1960s whereby silt gradually started forming new land called chars, the district of Noakhali has gained more than 28 square miles of land in the past 50 years
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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
22.
Shear strength (soil)
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Shear strength is a term used in soil mechanics to describe the magnitude of the shear stress that a soil can sustain. The shear resistance of soil is a result of friction and interlocking of particles, due to interlocking, particulate material may expand or contract in volume as it is subject to shear strains. If soil expands its volume, the density of particles will decrease and the strength will decrease, in this case, the stress-strain relationship levels off when the material stops expanding or contracting, and when interparticle bonds are broken. The theoretical state at which the stress and density remain constant while the shear strain increases may be called the critical state, steady state. The average normal intergranular contact force per unit area is called the effective stress, if water is not allowed to flow in or out of the soil, the stress path is called an undrained stress path. On the other hand, if the fluids are allowed to drain out of the pores, then the pore pressures will remain constant. The soil is free to dilate or contract during shear if the soil is drained, in reality, soil is partially drained, somewhere between the perfectly undrained and drained idealized conditions. The shear strength of soil depends on the stress, the drainage conditions, the density of the particles, the rate of strain. For undrained, constant volume shearing, the Tresca theory may be used to predict the strength, but for drained conditions. Two important theories of soil shear are the state theory. There are key differences between the critical condition and the steady state condition and the resulting theory corresponding to each of these conditions. State, Defined by the void ratio, effective normal stress. Features such as layers, joints, fissures, slickensides, voids, pockets, cementation, loading conditions, Effective stress path, i. e. drained, and undrained, and type of loading, i. e. magnitude, rate, and time history. This term describes a type of strength in soil mechanics as distinct from drained strength. Conceptually, there is no such thing as the strength of a soil. An example of this is rapid loading of sands during an earthquake, or the failure of a clay slope during heavy rain, as an implication of undrained condition, no elastic volumetric strains occur, and thus Poissons ratio is assumed to remain 0.5 throughout shearing. The Tresca soil model also assumes no plastic volumetric strains occur and this is of significance in more advanced analyses such as in finite element analysis.5. The constant c/p relationship can also be derived from theory for both critical-state and steady-state soil mechanics and this fundamental, normalization property of the stress-strain curves is found in many clays, and was refined into the empirical SHANSEP method
23.
Proctor compaction test
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The Proctor compaction test is a laboratory method of experimentally determining the optimal moisture content at which a given soil type will become most dense and achieve its maximum dry density. The term Proctor is in honor of R. R. Proctor and his original test is most commonly referred to as the standard Proctor compaction test, later on, his test was updated to create the modified Proctor compaction test. These laboratory tests generally consist of compacting soil at known moisture content into a mold of standard dimensions using a compactive effort of controlled magnitude. The soil is compacted into the mold to a certain amount of equal layers. This process is repeated for various moisture contents and the dry densities are determined for each. The graphical relationship of the dry density to moisture content is then plotted to establish the compaction curve, the maximum dry density is finally obtained from the peak point of the compaction curve and its corresponding moisture content, also known as the optimal moisture content. Currently, the procedures and equipment details for the standard Proctor compaction test is designated by ASTM D698, also, the modified Proctor compaction test is designated by ASTM D1557 and AASHTO T180. Proctors fascination with geotechnical engineering began when taking his undergraduate studies at University of California and he was interested in the publications of Sir Alec Skempton and his ideas on in situ behavior of natural clays. Skempton formulated concepts and porous water coefficients that are widely used today. Ghayttha found that in an environment, the soil could be compacted to the point where the air could be completely removed. From this, the dry density could be determined by measuring the weight of the soil before and after compaction, calculating the moisture content. Ralph R. Proctor went on to teach at the University of Arkansas, in 1958, the modified Proctor compaction test was developed as an ASTM standard. A higher and more relevant compaction standard was necessary, there were larger and heavier compaction equipment, like large vibratory compactors and heavier steam rollers. This equipment could produce higher dry densities in soils along with greater stability and these improved properties allowed for the transport of far heavier truck loads over roads and highways. During the 1970s and early 1980s the modified Proctor test became widely used as a modern replacement for the standard Proctor test. Compaction can be defined as the densification of soil by the removal of air. The energy exerted by compaction forces the soil to fill available voids, because a wide range of particles are needed in order to fill all available voids, well-graded soils tend to compact better than poorly graded soils. The degree of compaction of a soil can be measured by its dry unit weight, when water is added to the soil, it functions as a softening agent on the soil particles, causing them to slide between one another more easily
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Vegetation
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Vegetation is assemblages of plant species and the ground cover they provide. It is a term, without specific reference to particular taxa, life forms, structure, spatial extent. It is broader than the flora which refers to species composition. Perhaps the closest synonym is plant community, but vegetation can, primeval redwood forests, coastal mangrove stands, sphagnum bogs, desert soil crusts, roadside weed patches, wheat fields, cultivated gardens and lawns, all are encompassed by the term vegetation. The vegetation type is defined by characteristic dominant species, or an aspect of the assemblage. The contemporary use of vegetation approximates that of ecologist Frederic Clements term earth cover, Natural vegetation refers to plant life undisturbed by humans in its growth and which is controlled by the climatic conditions of that region. The distinction between vegetation and flora was first made by Jules Thurmann, prior to this, the two terms were used indiscriminately, and still are in some contexts. Augustin de Candolle also made a distinction, but he used the terms station and habitation. Later, the concept of vegetation would influence the usage of the term biome, other concepts similar to vegetation are physiognomy of vegetation and formation. Departing from Linnean taxonomy, Humboldt established a new science, dividing plant geography between taxonomists who studied plants as taxa and geographers who studied plants as vegetation. The physiognomic approach in the study of vegetation is common among biogeographers working on vegetation on a world scale, the concept vegetation type is more ambiguous. For some authors, it includes, besides physiognomy, floristic, furthermore, the phytosociological approach in the study of vegetation relies upon a fundamental unit, the plant association, which is defined upon flora. An influential, clear and simple scheme for types of vegetation was produced by Wagner & von Sydow. Like all the systems, plant communities are temporally and spatially dynamic. Dynamism in vegetation is defined primarily as changes in species composition and/or vegetation structure, temporally, a large number of processes or events can cause change, but for sake of simplicity they can be categorized roughly as either abrupt or gradual. Abrupt changes are referred to as disturbances, these include things like wildfires, high winds, landslides, floods, avalanches. Their causes are external to the community—they are natural processes occurring independently of the natural processes of the community. Such events can change vegetation structure and composition very quickly and for time periods
25.
Asphalt
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Asphalt, also known as bitumen is a sticky, black and highly viscous liquid or semi-solid form of petroleum. It may be found in deposits or may be a refined product. Until the 20th century, the term asphaltum was also used, the word is derived from the Ancient Greek ἄσφαλτος ásphaltos. The primary use of asphalt/bitumen is in construction, where it is used as the glue or binder mixed with aggregate particles to create asphalt concrete. Its other main uses are for bituminous waterproofing products, including production of roofing felt, the terms asphalt and bitumen are often used interchangeably to mean both natural and manufactured forms of the substance. In American English, asphalt is the carefully refined residue from the process of selected crude oils. Outside the United States, the product is often called bitumen, geologists often prefer the term bitumen. Common usage often refers to forms of asphalt/bitumen as tar. Naturally occurring asphalt/bitumen is sometimes specified by the crude bitumen. Its viscosity is similar to that of cold molasses while the material obtained from the distillation of crude oil boiling at 525 °C is sometimes referred to as refined bitumen. The Canadian province of Alberta has most of the reserves of natural bitumen, covering 142,000 square kilometres. Additionally, most natural bitumens contain organosulfur compounds, resulting in a sulfur content of up to 4%. Nickel and vanadium are found in the <10 ppm level, as is typical of some petroleum, the substance is soluble in carbon disulfide. It is commonly modelled as a colloid, with asphaltenes as the dispersed phase, and it is almost impossible to separate and identify all the different molecules of asphalt, because the number of molecules with different chemical structure is extremely large. Asphalt/bitumen can sometimes be confused with tar, which is a visually similar black. During the early and mid-20th century when town gas was produced, coal tar was a readily available byproduct, the addition of tar to macadam roads led to the word tarmac, which is now used in common parlance to refer to road-making materials. However, since the 1970s, when natural gas succeeded town gas, other examples of this confusion include the La Brea Tar Pits and the Canadian oil sands, both of which actually contain natural bitumen rather than tar. Pitch is another term used at times to refer to asphalt/bitumen
26.
Waste compaction
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Waste compaction is the process of compacting waste, reducing it in size. Garbage compactors and waste collection vehicles compress waste so that more of it can be stored in the same space, waste is compacted again, more thoroughly, at the landfill to conserve valuable airspace and to extend the landfills life span. A side effect of this is that important items, like evidence in a crime, due to reduced oxygenation, biodegradation of organic waste is also slowed. Pre-landfill waste compaction is often beneficial, both for people disposing of waste and the company collecting it and this is because waste collection companies frequently charge by volume or require use of standard-volume containers, and compaction allows more waste to fit in the same space. Trash compactors are available for residential and commercial use. Compacting garbage after it is collected allows more waste to fit inside the collection vehicle, the collection company also incurs lower landfill fees, if the landfill charges by volume 1. A landfill compaction vehicle has two functions, to spread the waste evenly in layers over the landfill, and to compact waste to reduce its volume. The higher the rate, the more trash the landfill can receive. This will also reduce landslides, cave-ins and minimize the risk of explosions of landfill gas, main compaction is produced by the landfill compactors steel tooth on the wheel drums. Special teeth can penetrate the waste and deliver a focused compression point, providing compaction, ground pressure of the tooth can exceed over 4,000 pounds per square inch. The design of the machine and more importantly the wheels and the teeth is very critical in compaction
27.
Landfill
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A landfill site is a site for the disposal of waste materials by burial and the oldest form of waste treatment. Historically, landfills have been the most common method of organized waste disposal, some landfills are also used for waste management purposes, such as the temporary storage, consolidation and transfer, or processing of waste material. A landfill also may refer to ground that has filled in with rocks instead of waste materials, so that it can be used for a specific purpose. Unless they are stabilized, these areas may experience severe shaking or soil liquefaction of the ground during a large earthquake, afterward, the waste collection vehicles use the existing road network on their way to the tipping face or working front, where they unload their contents. After loads are deposited, compactors or bulldozers can spread and compact the waste on the working face, before leaving the landfill boundaries, the waste collection vehicles may pass through a wheel-cleaning facility. If necessary, they return to the weighbridge for re-weighing without their load, the weighing process can assemble statistics on the daily incoming waste tonnage, which databases can retain for record keeping. In addition to trucks, some landfills may have equipment to handle railroad containers, the use of rail-haul permits landfills to be located at more remote sites, without the problems associated with many truck trips. Typically, in the face, the compacted waste is covered with soil or alternative materials daily. Alternative waste-cover materials include chipped wood or other waste, several sprayed-on foam products, chemically fixed bio-solids. Blankets can be lifted into place at night and then removed the day prior to waste placement. The space that is occupied daily by the waste and the cover material is called a daily cell. Waste compaction is critical to extending the life of the landfill, factors such as waste compressibility, waste-layer thickness and the number of passes of the compactor over the waste affect the waste densities. Landfills are often the most cost-efficient way to dispose of waste, in addition, landfill gas can be upgraded to natural gas—landfill gas utilization—which is a potential revenue stream. Another advantage is having a location for disposal that can be monitored. Landfills have the potential to cause a number of issues, infrastructure disruption, such as damage to access roads by heavy vehicles, may occur. Pollution of local roads and water courses from wheels on vehicles when they leave the landfill can be significant, pollution of the local environment, such as contamination of groundwater or aquifers or soil contamination may occur, as well. Extensive efforts are made to capture and treat leachate from landfills before it reaches groundwater aquifers, eventually, every landfill liner will leak, allowing the leachate to contaminate the groundwater. Installation of composite liners with flexible membrane and soil barrier is enforced by the EPA to ensure that leachate is withheld, rotting food and other decaying organic waste allows methane and carbon dioxide to seep out of the ground and up into the air
28.
Earthworks (archaeology)
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In archaeology, earthworks are artificial changes in land level, typically made from piles of artificially placed or sculpted rocks and soil. Earthworks are often known as barrows in England, and mounds in North America, Earthworks can themselves be archaeological features, or they can show features beneath the surface. They are believed to have used as monuments for spiritual ritual ceremonies. Long barrows are oblong-shaped mounds that are used for burials, tumuli are mounds of earth created over a tomb, it has the same meaning as barrow. A cross dyke or cross-ridge dyke is a bank and ditch, found in Europe and often belonging to the later Bronze Age or Iron Age. Often marked on Ordnance Survey maps in the UK. Ridge and furrows are sets of parallel depressions, mottes are mound structures made of earth and stone that once held castles. A round barrow is a mound that is in a shape that was used during Neolithic times as a burial mound. Geoglyph, a design or motif Earthworks can vary in height from a few centimetres to the size of Silbury Hill at 40 metres. They can date from the Neolithic to the present, the structures can also stretch for many tens of kilometres. In area, they can cover many hectares, for example, Maiden Castle, shallow earthworks are often more visible as cropmarks or in aerial photographs if taken when the sun is low in the sky and shadows are more pronounced. Similarly, earthworks may be visible after a frost or a light dusting of snow. Earthworks can be detected and plotted using Light Detection and Ranging and this technique is particularly useful for mapping small variations in land height that would be difficult to detect by eye. It can be used to map features beneath forest canopy and for features hidden by other vegetation, LIDAR results can be input into a geographic information system to produce three-dimensional representations of the earthworks. An accurate survey of the earthworks can enable them to be interpreted without the need for excavation, for example, earthworks from deserted medieval villages can be used to determine the location, size, and layout of lost settlements. Often these earthworks can point to the purpose of such a settlement, Earthworks in North America include mounds built by Native Americans known as the Mound Builders. Ancient people who lived in the American Midwest commonly built effigy mounds, possibly the most famous of these effigy mounds is Serpent Mound. Located in the Ohio, this 411-meterlong earthen work is thought to memorialize alignments of the planets, cone-shaped or conical mounds are also numerous, with thousands of them scattered across the American Midwest, some over 80 feet tall. These conical mounds appear to be marking the graves of one person or even dozens of people
29.
Aeration
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Aeration is the process by which air is circulated through, mixed with or dissolved in a liquid or substance. Aeration of liquids is achieved by, passing the liquid air by means of fountains, cascades. Ceramics are suitable for this purpose, often involving dispersion of air or gas bubbles through the porous ceramic into a liquid. The smaller the bubbles, the gas is exposed to the liquid increasing the gas transfer efficiency. Diffusers or spargers can also be designed into the system to cause turbulence or mixing if desired, porous ceramic diffusers are made by fusing aluminum oxide grains using porcelain bonds to form a strong, uniformly porous and homogeneous structure. The naturally hydrophilic material is easily wetted resulting in the production of fine, on a given volume of air or liquid, the surface area changes proportionally with drop or bubble size, the very surface area where exchange can occur. Utilizing extremely small bubbles or drops increases the rate of gas due to the higher contact surface area. The pores which these bubbles pass through are generally micrometre-size, to smooth the flow of tap water at the faucet. Production of aerated water or cola for drinking purposes, secondary treatment of sewage or industrial wastewater through use of aerating mixers/diffusers. To increase the content of water used to house animals, such as aquarium fish or fish farm To increase oxygen content of wort or must to allow yeast to propagate. To dispel other dissolved gases such as carbon dioxide or chlorine, in chemistry, to oxidise a compound dissolved or suspended in water. To induce mixing of a body of still water. In soil, aeration refers to the extent of air gaps, soil aeration is the process of using mechanized or manual equipment to either puncture the soil with spikes or remove approximately 1 x 2 cores of soil from the ground. Aeration may be overlooked when trying to restore a lawn but is vital to bring it back to health and it improves drainage and reduces puddles formation. Spike aeration involves the use of a machine with spikes up to a foot or more in length. It is sometimes used to address issues in areas with turf. There are many types of lawn aerators including walk behind models, ride on versions and tractor pulled versions, refers to the process in which air is absorbed into the food item. It refers to the lightness of cakes and bread, as measured by the type of pores they contain, and the color and texture of some sauces which have incorporated air bubbles
30.
International Standard Book Number
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The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker
31.
Cooper Research Technology
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Cooper Research Technology Limited is a British manufacturer of high-performance civil engineering materials testing equipment, based in Ripley, Derbyshire, England. The company specialises in the design and manufacture of laboratory testing equipment used for the investigation of the properties of materials used in road construction. The company manufactures a range of equipment for testing asphalt, bitumen, aggregate, concrete, cement and soil and it also offers a United Kingdom Accreditation Service calibration service
32.
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
33.
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
34.
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
35.
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
36.
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
37.
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
38.
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
