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Schoharie Creek Bridge Collapse
The Schoharie Creek Bridge was a New York State Thruway (I-90) bridge over the Schoharie Creek near Fort Hunter and the Mohawk River in New York State. On April 5, 1987 it collapsed due to bridge scour at the foundations after a record rainfall. The collapse killed ten people. The replacement bridge was completed and fully open to traffic on May 21, 1988. The failure of the Schoharie Creek Bridge motivated improvement in bridge design and inspection procedures within New York and beyond. Bridge design and construction The final design for the bridge was approved in January 1952 by the New York State Department of Transportation (previously the New York State Department of Public Works). The design described a crossing consisting of five simply supported spans with nominal lengths of , , , , and . The bridge was supported with pier frames along with abutments at each end. The pier frames were constructed of two slightly tapered columns with tie beams. The columns were fixed i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schoharie Creek
Schoharie Creek is a river in New York that flows north from the foot of Indian Head Mountain in the Catskills through the Schoharie Valley to the Mohawk River. It is twice impounded north of Prattsville to create New York City's Schoharie Reservoir and the Blenheim-Gilboa Power Project. During the American Revolutionary War, Iroquois Indian attacks against the cluster of farms in the valley of the Cobleskill Creek tributary was the site of the Cobleskill Massacre (May 1778), virtually depopulating settlements in the southern Mohawk valley. News of this and two other mixed Tory-Indian guerrilla attacks led to an appropriation of funds for the Sullivan Expedition dispatched by General Washington in 1779 to break the threat of Indian raids. The Erie Canal crossed over the creek by an aqueduct at Schoharie Crossing State Historic Site. Two notable bridge collapses have occurred on Schoharie Creek. In 1987, two spans of the New York State Thruway collapsed. On August 28, 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superstructure
A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships. Aboard ships and large boats On water craft, the superstructure consists of the parts of the ship or a boat, including sailboats, fishing boats, passenger ships, and submarines, that project above her main deck. This does not usually include its masts or any armament turrets. Note that in modern times, turrets do not always carry naval artillery, but they can also carry missile launchers and/or antisubmarine warfare weapons. The size of a watercraft's superstructure can have many implications in the performance of ships and boats, since these structures can alter their structural rigidity, their displacements, and/or stability. These can be detrimental to any vessel's performance if they are taken into consideration incorrectly. The height and the weight of superstructure on board a ship or a bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridge Scour
Bridge scour is the removal of sediment such as sand and gravel from around bridge abutments or piers. Hydrodynamic scour, caused by fast flowing water, can carve out ''scour holes'', compromising the integrity of a structure. In the United States, bridge scour is one of the three main causes of bridge failure (the others being collision and overloading). It has been estimated that 60% of all bridge failures result from scour and other hydraulic-related causes.Mark N. LandersBridge Scour Data Management Published in ''Hydraulic Engineering: Saving a Threatened Resource—In Search of Solutions: Proceedings of the Hydraulic Engineering sessions at Water Forum ’92.'' Baltimore, Maryland, August 2–6, 1992. Published by American Society of Civil Engineers. It is the most common cause of highway bridge failure in the United States, [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schoharie Creek 1-50 Model CSU FOgden , surrounding the above creek
{{geodis ...
Schoharie may refer to: *Schoharie County, New York, USA **Schoharie (town), New York, in the above county ***Schoharie (village), New York, in the above town *Schoharie Creek, a stream in upstate New York, USA **Schoharie Valley The Schoharie Valley is a corridor that runs through Schoharie County from Schoharie, New York to Gilboa, New York. Geography The Schoharie Valley is made up of plains surrounding the Schoharie Creek. Within the Schoharie Valley are the towns of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angle Of Attack
In fluid dynamics, angle of attack (AOA, α, or \alpha) is the angle between a reference line on a body (often the chord line of an airfoil) and the vector representing the relative motion between the body and the fluid through which it is moving. Angle of attack is the angle between the body's reference line and the oncoming flow. This article focuses on the most common application, the angle of attack of a wing or airfoil moving through air. In aerodynamics, angle of attack specifies the angle between the chord line of the wing of a fixed-wing aircraft and the vector representing the relative motion between the aircraft and the atmosphere. Since a wing can have twist, a chord line of the whole wing may not be definable, so an alternate reference line is simply defined. Often, the chord line of the root of the wing is chosen as the reference line. Another choice is to use a horizontal line on the fuselage as the reference line (and also as the longitudinal axis). Some aut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Flow
In fluid dynamics, flow can be decomposed into primary plus secondary flow, a relatively weaker flow pattern superimposed on the stronger primary flow pattern. The primary flow is often chosen to be an exact solution to simplified or approximated (for instance, inviscid) governing equations, such as potential flow around a wing or geostrophic current or wind on the rotating Earth. In that case, the secondary flow usefully spotlights the effects of complicated real-world terms neglected in those approximated equations. For instance, the consequences of viscosity are spotlighted by secondary flow in the viscous boundary layer, resolving the tea leaf paradox. As another example, if the primary flow is taken to be a balanced flow approximation with net force equated to zero, then the secondary circulation helps spotlight acceleration due to the mild imbalance of forces. A smallness assumption about secondary flow also facilitates linearization. In engineering secondary flow also id ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horseshoe Vortex
The horseshoe vortex model is a simplified representation of the vortex system present in the flow of air around a wing. This vortex system is modelled by the ''bound vortex'' (bound to the wing) and two '' trailing vortices'', therefore having a shape vaguely reminiscent of a horseshoe. A starting vortex is shed as the wing begins to move through the fluid, which dissipates under the action of viscosity, as do the trailing vortices far behind the aircraft. The downwash is associated with induced drag and is a component of the system of trailing vortices. The horseshoe vortex model is unrealistic in that it implies uniform circulation (and hence, according to the Kutta–Joukowski theorem, uniform lift) at all sections on the wingspan. In a more realistic model, the lifting-line theory, the vortex strength varies along the wingspan, and the loss in vortex strength is shed as a vortex ''sheet'' all along the trailing edge, rather than as a single trail at the wing-tips. Neverthe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shallow Foundation
A shallow foundation is a type of building Foundation (engineering), foundation that transfers structural load to the earth very near to the surface, rather than to a subsurface layer or a range of depths, as does a deep foundation. Customarily, a shallow foundation is considered as such when the width of the entire foundation is greater than its depth. In comparison to deep foundations, shallow foundations are less technical, thus making them more economical and the most widely used for relatively light structures. Types of shallow foundation Footings are always wider than the members that they support. Structural loads from a column or wall are usually greater than 1000kPa, while the soil's bearing capacity is commonly less than that (typically less than 400kPa). By possessing a larger bearing area, the foundation distributes the pressure to the soil, decreasing the bearing pressure to within allowable values. A structure is not limited to one footing. Multiple types of footings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York State Thruway Authority
The New York State Thruway Authority (NYSTA) is a public benefit corporation in New York State, United States. The NYSTA was formed in 1950 with the responsibility of constructing, maintaining, and operating the New York State Thruway, a system of limited-access highways within the state. Organization In August 2017, Matthew J. Driscoll was appointed by Governor Andrew Cuomo as the Acting Executive Director of the New York State Thruway Authority. The executive officers report to a 6-member board of directors. In 2017, the authority had operating expenses of $872.17 million, an outstanding debt of $8.827 billion, and a staffing level of 3,754 people. The authority operates without financial assistance from the state of New York. All debt is paid for through tolls and fees. History Formation A toll superhighway connecting the major cities of the state of New York that would become part of a larger nationwide highway network was proposed as early as 1949. Construction was i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semitrailer
A semi-trailer is a trailer without a front axle. In the United States, the term is also used to refer to the combination of a truck and a semi-trailer; a tractor-trailer. A large proportion of a semi-trailer's weight is supported by a tractor unit, or a detachable front-axle assembly known as a dolly, or the tail of another trailer. The other portion of the semi-trailer's weight is semi-supported (half-supported) by its own wheels, which only support the rear of the semi-trailer. A semi-trailer is normally equipped with landing gear (legs which can be lowered) to support it when it is uncoupled. Many semi-trailers have wheels that are capable of being totally dismounted and are also relocatable (repositionable) to better distribute load to bearing wheel weight factors. Semi-trailers are more popular for transport than full trailers, which have both front and rear axles. Ease of backing is cited as one of the semi's chief advantages. A road tractor coupled to a semi-trailer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tractor
A tractor is an engineering vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a trailer or machinery such as that used in agriculture, mining or construction. Most commonly, the term is used to describe a farm vehicle that provides the power and traction to mechanize agricultural tasks, especially (and originally) tillage, and now many more. Agricultural implements may be towed behind or mounted on the tractor, and the tractor may also provide a source of power if the implement is mechanised. Etymology The word ''tractor'' was taken from Latin, being the agent noun of ''trahere'' "to pull". The first recorded use of the word meaning "an engine or vehicle for pulling wagons or plows" occurred in 1896, from the earlier term " traction motor" (1859). National variations In the UK, Ireland, Australia, India, Spain, Argentina, Slovenia, Serbia, Croatia, the Netherlands, and Germany, the word "tractor" u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Transportation Safety Board
The National Transportation Safety Board (NTSB) is an independent U.S. government investigative agency responsible for civil transportation accident investigation. In this role, the NTSB investigates and reports on aviation accidents and incidents, certain types of highway crashes, ship and marine accidents, pipeline incidents, bridge failures, and railroad accidents. The NTSB is also in charge of investigating cases of hazardous materials releases that occur during transportation. The agency is based in Washington, D.C. It has four regional offices, located in Anchorage, Alaska; Denver, Colorado; Ashburn, Virginia; and Seattle, Washington. The agency also operates a national training center at its Ashburn facility. History The origin of the NTSB was in the Air Commerce Act of 1926, which assigned the United States Department of Commerce responsibility for investigating domestic aviation accidents. Before the NTSB, the Federal Aviation Administration's (FAA; at the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
