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Revetment
A revetment in stream restoration, river engineering or coastal engineering is a facing of impact-resistant material (such as stone, concrete, sandbags, or wooden piles) applied to a bank or wall in order to absorb the energy of incoming water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ... and protect it from erosion. River or coastal revetments are usually built to preserve the existing uses of the shoreline and to protect the slope. In military engineering it is a sloped structure formed to secure an area from artillery, bombing, or stored explosives. Freshwater revetments Many revetments are used to line the banks of freshwater rivers, lakes, and man-made reservoirs, especially to prevent damage during periods of floods or heavy seasonal rains (see riprap). Many mater ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Revetment 2
A revetment in stream restoration, river engineering or coastal engineering is a facing of impact-resistant material (such as stone, concrete, sandbags, or wooden piles) applied to a bank or wall in order to absorb the energy of incoming water and protect it from erosion. River or coastal revetments are usually built to preserve the existing uses of the shoreline and to protect the slope. In military engineering it is a sloped structure formed to secure an area from artillery, bombing, or stored explosives. Freshwater revetments Many revetments are used to line the banks of freshwater rivers, lakes, and man-made reservoirs, especially to prevent damage during periods of floods or heavy seasonal rains (see riprap). Many materials may be used: wooden piles, loose-piled boulders or concrete shapes, or more solid banks. Concrete revetments are the most common type of infrastructure used to control the Mississippi River. More than of concrete matting has been placed in river ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Revetment
Dynamic revetment, also known as a "cobble berm", uses gravel or cobble-sized rocks to mimic a natural cobble storm beach for the purpose of reducing wave energy and stopping or slowing coastal erosion. Unlike seawalls, dynamic revetment is designed to allow wave action to rearrange the stones into an equilibrium profile, disrupting wave action and dissipating wave energy as the cobbles move. This can reduce the wave reflection which often contributes to beach scouring. Principle The goal is to design structures that are natural in appearance and function while also providing acceptable protection to coastal properties, combining the benefits of ecologically responsive shore protection methods with those of conventional armor‑stone revetments or seawalls. Natural self-protection by landslides was demonstrated in the early 1990s when, in an effort to stabilize the Lone Tree landslide 15 km north of San Francisco, California Department of Transportation dumped excavated ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breakwater (structure)
A breakwater is a permanent structure constructed at a coastal area to protect against tides, currents, waves, and storm surges. Part of a coastal management system, breakwaters are installed to minimize erosion, and to protect anchorages, helping isolate vessels within them from marine hazards such as prop washes and wind-driven waves. A breakwater, also known in some contexts as a jetty, may be connected to land or freestanding, and may contain a walkway or road for vehicle access. On beaches where longshore drift threatens the erosion of beach material, smaller structures on the beach, usually perpendicular to the water's edge, may be installed. Their action on waves and current is intended to slow the longshore drift and discourage mobilisation of beach material. In this usage they are more usually referred to as groynes. Purposes Breakwaters reduce the intensity of wave action in inshore waters and thereby provide safe harbourage. Breakwaters may also be small structu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mississippi River
The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky and Appalachian mountains. The main stem is entirely within the United States; the total drainage basin is , of which only about one percent is in Canada. The Mississippi ranks as the thirteenth-largest river by discharge in the world. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana. Native Americans have lived along the Mississippi River and its tributaries for thousands of years. Most were hunter-ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape Lookout Dynamic Revetment 2020
A cape is a clothing accessory or a sleeveless outer garment which drapes the wearer's back, arms, and chest, and connects at the neck. History Capes were common in medieval Europe, especially when combined with a hood in the chaperon. They have had periodic returns to fashion - for example, in nineteenth-century Europe. Roman Catholic clergy wear a type of cape known as a ferraiolo, which is worn for formal events outside a ritualistic context. The cope is a liturgical vestment in the form of a cape. Capes are often highly decorated with elaborate embroidery. Capes remain in regular use as rainwear in various military units and police forces, in France for example. A gas cape was a voluminous military garment designed to give rain protection to someone wearing the bulky gas masks used in twentieth-century wars. Rich noblemen and elite warriors of the Aztec Empire would wear a tilmàtli; a Mesoamerican cloak/cape used as a symbol of their upper status. Cloth and clothing w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parapet
A parapet is a barrier that is an extension of the wall at the edge of a roof, terrace, balcony, walkway or other structure. The word comes ultimately from the Italian ''parapetto'' (''parare'' 'to cover/defend' and ''petto'' 'chest/breast'). Where extending above a roof, a parapet may simply be the portion of an exterior wall that continues above the edge line of the roof surface, or may be a continuation of a vertical feature beneath the roof such as a fire wall or party wall. Parapets were originally used to defend buildings from military attack, but today they are primarily used as guard rails, to conceal rooftop equipment, reduce wind loads on the roof, and to prevent the spread of fires. In the Bible the Hebrews are obligated to build a parapet on the roof of their houses to prevent people falling (Deuteronomy 22:8). Parapet types Parapets may be plain, embattled, perforated or panelled, which are not mutually exclusive terms. *Plain parapets are upward extensions of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retaining Wall
Retaining walls are relatively rigid walls used for supporting soil laterally so that it can be retained at different levels on the two sides. Retaining walls are structures designed to restrain soil to a slope that it would not naturally keep to (typically a steep, near-vertical or vertical slope). They are used to bound soils between two different elevations often in areas of terrain possessing undesirable slopes or in areas where the landscape needs to be shaped severely and engineered for more specific purposes like hillside farming or roadway overpasses. A retaining wall that retains soil on the backside and water on the frontside is called a seawall or a bulkhead. Definition A wall for holding in place a mass of earth or the like, as at the edge of a terrace or excavation. A retaining wall is a structure designed and constructed to resist the lateral pressure of soil, when there is a desired change in ground elevation that exceeds the angle of repose of the soil. A basement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Civil War
The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by states that had seceded. The central cause of the war was the dispute over whether slavery would be permitted to expand into the western territories, leading to more slave states, or be prevented from doing so, which was widely believed would place slavery on a course of ultimate extinction. Decades of political controversy over slavery were brought to a head by the victory in the 1860 U.S. presidential election of Abraham Lincoln, who opposed slavery's expansion into the west. An initial seven southern slave states responded to Lincoln's victory by seceding from the United States and, in 1861, forming the Confederacy. The Confederacy seized U.S. forts and other federal assets within their borders. Led by Confederate President Jefferson Davis, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Park Service
The National Park Service (NPS) is an agency of the United States federal government within the U.S. Department of the Interior that manages all national parks, most national monuments, and other natural, historical, and recreational properties with various title designations. The U.S. Congress created the agency on August 25, 1916, through the National Park Service Organic Act. It is headquartered in Washington, D.C., within the main headquarters of the Department of the Interior. The NPS employs approximately 20,000 people in 423 individual units covering over 85 million acres in all 50 states, the District of Columbia, and US territories. As of 2019, they had more than 279,000 volunteers. The agency is charged with a dual role of preserving the ecological and historical integrity of the places entrusted to its management while also making them available and accessible for public use and enjoyment. History Yellowstone National Park was created as the first national par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trench Construction Diagram 1914
A trench is a type of excavation or in the ground that is generally deeper than it is wide (as opposed to a wider gully, or ditch), and narrow compared with its length (as opposed to a simple hole or pit). In geology, trenches result from erosion by rivers or by geological movement of tectonic plates. In civil engineering, trenches are often created to install underground utilities such as gas, water, power and communication lines. In construction, trenches are dug for foundations of buildings, retaining walls and dams, and for cut-and-cover construction of tunnels. In archaeology, the "trench method" is used for searching and excavating ancient ruins or to dig into strata of sedimented material. In geotechnical engineering, trenches serve for locating faults and investigating deep soil properties. In trench warfare, soldiers occupy trenches to protect them against weapons fire. Trenches are dug by use of manual tools such as shovels and pickaxes, or by heavy equipment such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most widely used building material. Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminum combined. Globally, the ready-mix concrete industry, the largest segment of the concrete market, is projected to exceed $600 billion in revenue by 2025. This widespread use results in a number of environmental impacts. Most notably, the production process for cement produces large volumes of greenhouse gas emissions, leading to net 8% of global emissions. Other environmental concerns include widespread illegal sand mining, impacts on the surrounding environment such as increased surface runoff or urban heat island effect, and potential public health implications from toxic ingredients. Significant research and development is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
