42-722: The Oesterdam ( English : Oyster Dam ) is a compartmentalisation dam in The Netherlands , situated between Tholen and South Beveland in the eastern part of the Eastern Scheldt . The dam, with a length of 10.5 kilometres, is the longest structure built for the Delta Works . The Oesterdam was necessitated, like the Philipsdam , after the decision was taken to close off the Eastern Scheldt with
84-505: A storm surge barrier , rather than a solid dam. The dam contains a large sluice , the Bergse Diepsluis , and is located adjacent to a pair of sluices at Kreekrak , where about 80,000 ships pass every year. The Oesterdam was not originally part of the planned Delta Works, but rather is one of the compartmentalisation dams which became necessary when it was decided not to close off the Eastern Scheldt, but to provide it with
126-434: A documentary called " Sand Wars " about the impact of the lack of construction sand. It shows the ecological and economic effects of both legal and illegal trade in construction sand. To retrieve the sand, the method of hydraulic dredging is used. This works by pumping the top few meters of sand out of the water and filling it into a boat, which is then transported back to land for processing. All marine life mixed in with
168-610: A high olivine content. Many sands, especially those found extensively in Southern Europe , have iron impurities within the quartz crystals of the sand, giving a deep yellow color. Sand deposits in some areas contain garnets and other resistant minerals, including some small gemstones . Rocks erode or weather over a long period of time, mainly by water and wind, and their sediments are transported downstream. These sediments continue to break apart into smaller pieces until they become fine grains of sand. The type of rock
210-600: A permeable barrier. The reduced tidal movement in the estuary associated with this decision meant that, to achieve sufficient tidal movement, the surface area of the Eastern Scheldt would have to be reduced. This was achieved by the construction of compartmentalisation dams: the Markiezaatskade , the Philipsdam , the Volkerakdam , and the Oesterdam. With the construction of the compartmentalisation works,
252-489: A result. People sometimes dig holes in the sand at beaches for recreational purposes, but if too deep they can result in serious injury or death in the event of a collapse. Manufactured sand (M sand) is sand made from rock by artificial processes, usually for construction purposes in cement or concrete. It differs from river sand by being more angular, and has somewhat different properties. In Dubai , United Arab Emirates , sand needed to construct infrastructure and create
294-483: A significant dredging industry, raising environmental concerns over fish depletion, landslides, and flooding. Countries such as China, Indonesia, Malaysia, and Cambodia ban sand exports, citing these issues as a major factor. It is estimated that the annual consumption of sand and gravel is 40 billion tons and sand is a US$ 70 billion global industry. With increasing use, more is expected to come from recycling and alternatives to sand. The global demand for sand in 2017
336-660: A unique design for the dam. The chosen plan for the Oesterdam entailed a path from the Scheldt-Rhine Canal through the Bathse polders in a northerly direction, incorporating a separate spillway channel leading to a sluice in the Western Scheldt – the Bathse sluice – along with enhancements to the Canal through South Beveland. In the initial phases, the Bathse spillway channel's dam body was positioned west of
378-403: A volume of approximately 0.00012 cubic millimetres, to 2 mm, a volume of approximately 4.2 cubic millimetres, the difference in volumes being 34,688 measures difference. Any particle falling within this range of sizes is termed a sand grain . Sand grains are between gravel (with particles ranging from 2 mm up to 64 mm by the latter system, and from 4.75 mm up to 75 mm in
420-429: Is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt . Sand can also refer to a textural class of soil or soil type; i.e., a soil containing more than 85 percent sand-sized particles by mass. The composition of sand varies, depending on the local rock sources and conditions, but
462-508: Is called grus in geology or sharp sand in the building trade where it is preferred for concrete, and in gardening where it is used as a soil amendment to loosen clay soils. Sand that is transported long distances by water or wind will be rounded, with characteristic abrasion patterns on the grain surface. Desert sand is typically rounded. People who collect sand as a hobby are known as arenophiles . Organisms that thrive in sandy environments are psammophiles. Only some sands are suitable for
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#1732781106430504-572: Is in high demand. Desert sand, although plentiful, is not suitable for concrete. Fifty billion tons of beach sand and fossil sand are used each year for construction. The exact definition of sand varies. The scientific Unified Soil Classification System used in engineering and geology corresponds to US Standard Sieves, and defines sand as particles with a diameter of between 0.074 and 4.75 millimeters. By another definition, in terms of particle size as used by geologists , sand particles range in diameter from 0.0625 mm (or 1 ⁄ 16 mm)
546-474: Is the most common mineral resistant to weathering . The composition of mineral sand is highly variable, depending on the local rock sources and conditions. The bright white sands found in tropical and subtropical coastal settings are eroded limestone and may contain coral and shell fragments in addition to other organic or organically derived fragmental material, suggesting that sand formation depends on living organisms, too. The gypsum sand dunes of
588-500: Is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years, as in the Caribbean . Somewhat more rarely, sand may be composed of calcium sulfate , such as gypsum and selenite , as is found in places such as White Sands National Park and Salt Plains National Wildlife Refuge in the U.S. Sand is a non-renewable resource over human timescales, and sand suitable for making concrete
630-514: The Krumbein phi scale , where size is Φ = -log 2 D; D being the particle size in mm. On this scale, for sand the value of Φ varies from −1 to +4, with the divisions between sub-categories at whole numbers. The most common constituent of sand, in inland continental settings and non-tropical coastal settings, is silica (silicon dioxide, or SiO 2 ), usually in the form of quartz , which, because of its chemical inertness and considerable hardness,
672-594: The United States Department of Agriculture was 0.05 mm. A 1953 engineering standard published by the American Association of State Highway and Transportation Officials set the minimum sand size at 0.074 mm. Sand feels gritty when rubbed between the fingers. Silt , by comparison, feels like flour . ISO 14688 grades sands as fine, medium, and coarse with ranges 0.063 mm to 0.2 mm to 0.63 mm to 2.0 mm. In
714-687: The White Sands National Park in New Mexico are famous for their bright, white color. Arkose is a sand or sandstone with considerable feldspar content, derived from weathering and erosion of a (usually nearby) granitic rock outcrop. Some sands contain magnetite , chlorite , glauconite , or gypsum . Sands rich in magnetite are dark to black in color, as are sands derived from volcanic basalts and obsidian . Chlorite - glauconite bearing sands are typically green in color, as are sands derived from basaltic lava with
756-724: The Bergse Diepsluis to Tholen with a cable car and concrete blocks. Construction commenced in 1979 with the establishment of a work island on the Speelmansplaten, which was completed by 1980. The geotechnical and engineering geology challenges during the construction of the Oesterdam were substantial. The Holocene strata, extending from N.A.P. -5 m to -16 metres, were irregular, consisting of sand , peat , and clay layers of varying thickness. Beneath these, Pleistocene layers included deposits of sand with interspersed clay and shell grit. Towards Speelmansplaten and
798-585: The Kreekrak locks, intended to become operational concurrent with the completion of the Oesterdam. The proposed lock connecting the Zoommeer and the Eastern Scheldt was planned to be situated southwest of the Tholense Gap. This location was selected for its feasibility and its connection to an easily constructible section of the dam over the Speelmansplaten. This configuration resulted in two remaining gaps,
840-690: The Marolle Gap, the Holocene layer's thickness decreased, indicating lesser erosion over time. In some areas, thick deposits of the Dunkirk clay formation were directly on top of peat, or beneath a sand covering. Significant erosion by the Scheldt river had previously formed a valley in the southernmost 100 metres of the works, which had later filled with a complex mix of clay and sand. Geotechnical investigations had revealed poor subsoil quality at
882-536: The Marollegat and the Tholense Gap, that needed closure. Construction began after the completion of the Markiezaatskade dam (1981 - 1983), the tidal effects of the completed dam making the construction of the Oesterdam easier. The initial strategy for the Oesterdam's construction involved using a sand closure for the extensive southern segment up to the new Bergse Diepsluis, and completing the section from
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#1732781106430924-487: The Sahara is sand dunes, while 70% is bare rock. The wind is responsible for creating these different environments and shaping the sand to be round and smooth. These properties make desert sand unusable for construction. Beach sand is also formed by erosion. Over thousands of years, rocks are eroded near the shoreline from the constant motion of waves and the sediments build up. Weathering and river deposition also accelerate
966-465: The Speelmansplaten and Marolle Gap dike sections. To minimise instability risks during construction, various solutions were explored, such as supporting berms, vertical drainage, soil improvement, and phased construction with specific profiles to ensure stability. For the construction of the dam body, particular attention was paid to the soil structure. The design followed the top of the load-bearing Pleistocene sand. A uniformly wide base width of 76 metres
1008-473: The United States, sand is commonly divided into five sub-categories based on size: very fine sand ( 1 ⁄ 16 – 1 ⁄ 8 mm diameter), fine sand ( 1 ⁄ 8 mm – 1 ⁄ 4 mm), medium sand ( 1 ⁄ 4 mm – 1 ⁄ 2 mm), coarse sand ( 1 ⁄ 2 mm – 1 mm), and very coarse sand (1 mm – 2 mm). These sizes are based on
1050-441: The construction industry, for example for making concrete . Grains of desert sand are rounded by being blown in the wind, and for this reason do not produce solid concrete, unlike the rough sand from the sea. Because of the growth of population and of cities and the consequent construction activity there is a huge demand for these special kinds of sand, and natural sources are running low. In 2012 French director Denis Delestrac made
1092-438: The extracted sand is killed and the ecosystem can continue to suffer for years after the mining is complete. Not only does this affect marine life, but also the local fishing industries because of the loss of life, and communities living close to the water's edge. When sand is taken out of the water it increases the risk of landslides, which can lead to loss of agricultural land and/or damage to dwellings. Sand's many uses require
1134-585: The former) and silt (particles smaller than 0.0625 mm down to 0.004 mm). The size specification between sand and gravel has remained constant for more than a century, but particle diameters as small as 0.02 mm were considered sand under the Albert Atterberg standard in use during the early 20th century. The grains of sand in Archimedes ' The Sand Reckoner written around 240 BCE, were 0.02 mm in diameter. A 1938 specification of
1176-609: The freshwater Volkerak-Zoommeer was created, with benefits for agriculture . At the same time, a tide-free shipping route was created from the Volkerak locks to Antwerp . The Commissie Compartimentering Oosterschelde (English: Committee for Compartmentalisation of the Eastern Scheldt) was formed under the aegis of the Dutch Minister of Transport and Water Management. Its mandate included reporting to both
1218-548: The minister and the provincial authorities of Zeeland and North Brabant by 30 April 1975. This report was to cover the technical, planning, and financial considerations of various proposals for compartmentalising the Eastern Scheldt. The necessity of this committee arose from the need to maintain a substantial tidal difference at Yerseke and to ensure tide-independent inland navigation between Antwerp and Rotterdam , in accordance with an existing treaty with Belgium . The committee evaluated multiple alternatives, each suggesting
1260-409: The most common constituent of sand in inland continental settings and non- tropical coastal settings is silica (silicon dioxide, or SiO 2 ), usually in the form of quartz . Calcium carbonate is the second most common type of sand. One such example of this is aragonite , which has been created over the past 500 million years by various forms of life, such as coral and shellfish . It
1302-437: The process of creating a beach, along with marine animals interacting with rocks, such as eating the algae off of them. Once there is a sufficient amount of sand, the beach acts as a barrier to keep the land from eroding any further. This sand is ideal for construction as it is angular and of various sizes. Marine sand (or ocean sand) comes from sediments transported into the ocean and the erosion of ocean rocks. The thickness of
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1344-645: The project included the Aquarius, the Sliedrecht 27, the Zuiderklip, and the Mercurius. The production data of some of the dredgers, showing the increase in output from the originally planned sand closure volumes, is presented in the table below: In 1986, the dam's closure was executed using sand as the primary material. The construction of the road (N659) across the dam was completed in 1989. This new route
1386-461: The rate the sand can replenish, making it a non-renewable resource. Sand dunes are a consequence of dry conditions or wind deposition. The Sahara Desert is very dry because of its geographic location and proximity to the equator . It is known for its vast sand dunes, which exist mainly due to a lack of vegetation and water. Over time, wind blows away fine particles, such as clay and dead organic matter, leaving only sand and larger rocks. Only 15% of
1428-460: The sand because they do not have as much time to dissolve away. The term for sand formed by weathering is "epiclastic." Sand from rivers are collected either from the river itself or its flood plain and accounts for the majority of the sand used in the construction industry. Because of this, many small rivers have been depleted, causing environmental concern and economic losses to adjacent land. The rate of sand mining in such areas greatly outweighs
1470-480: The sand layer varies, however it is common to have more sand closer to land; this type of sand is ideal for construction and is a very valuable commodity. Europe is the main miners of marine sand, which greatly hurts ecosystems and local fisheries. The study of individual grains can reveal much historical information as to the origin and kind of transport of the grain. Quartz sand that is recently weathered from granite or gneiss quartz crystals will be angular. It
1512-411: The sediment originated from and the intensity of the environment give different compositions of sand. The most common rock to form sand is granite , where the feldspar minerals dissolve faster than the quartz , causing the rock to break apart into small pieces. In high energy environments rocks break apart much faster than in more calm settings. In granite rocks this results in more feldspar minerals in
1554-493: The user to wear respiratory protection to avoid breathing the resulting fine silica dust . Safety data sheets for silica sand state that "excessive inhalation of crystalline silica is a serious health concern." In areas of high pore water pressure , sand and salt water can form quicksand , which is a colloid hydrogel that behaves like a liquid. Quicksand produces a considerable barrier to escape for creatures caught within, who often die from exposure (not from submersion) as
1596-635: Was 9.55 billion tons as part of a $ 99.5 billion industry. In April 2022, the United Nations Environment Programme (UNEP) published a report stating that 50 billion tons of sand and gravel were being used every year. The report made 10 recommendations, including a ban on beach extraction, to avert a crisis, and move toward a circular economy for the two resources. While sand is generally non-toxic, sand-using activities such as sandblasting require precautions. Bags of silica sand used for sandblasting now carry labels warning
1638-511: Was adopted for simplicity, widened to 110 metres near the last closing gap of the Marolle Gap to minimise instability risks. In the South dike section, the subsoil allowed for direct construction on the existing ground over 100 metres. The termination of the excavation work was strategically planned to ensure stability. Specific requirements were set for dam body construction in transition areas, focusing on maintaining stability and integrity. The dam
1680-857: Was established at the Bergse Diepsluis in July 2022. This centre serves as a memorial and educational point, detailing the history of approximately 250 villages in Zeeland that were submerged in Reimerswaal (in the period 1550-1650) and elsewhere in the province. English Language Too Many Requests If you report this error to the Wikimedia System Administrators, please include the details below. Request from 172.68.168.226 via cp1108 cp1108, Varnish XID 220860429 Upstream caches: cp1108 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 08:05:06 GMT Sand Sand
1722-519: Was inaugurated by the Commissioner of the King , Kees Boertien , marking its official opening to the public. The Bergse Diepsluis, situated at the northern extremity of the dam, stands on the historical site of the submerged city of Reimerswaal . The city was destroyed by repeated floods , and the last citizens left in 1632. Recognising the historical significance of the area, an information centre
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1764-592: Was then constructed in stages. Owing to delays and advancements in dredging technology, which offered increased capacities at relatively lower costs, it was later decided to execute the Tholense Gat closure also with sand. This approach necessitated creating an extended tidal curve for several days, by partially closing the Oosterscheldekering . An assessment of the environmental impact of this method deemed it acceptable. The dredging vessels used on
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