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27-489: The High Level Bridge starts on the east at the center line of West 9th Street and Superior, and extends across the Cuyahoga Valley to the junction of West 25th Street and Detroit Avenue. It is 3,112 feet (949 m) long. The total cost, including the land and a right of way, was $ 5,407,000, split as $ 1,687,200 was for land and $ 3,719,800 for the superstructure. The bridge has 96 feet (29 m) of clearance above

54-443: A combination of wood and metal such as a flitch beam . Beams primarily carry vertical gravitational forces , but they are also used to carry horizontal loads such as those due to earthquake or wind, or in tension to resist rafter thrust ( tie beam ) or compression ( collar beam ). The loads carried by a beam are transferred to columns , walls , or girders , then to adjacent structural compression members , and eventually to

81-498: A load pushing parallel to its axis would be a strut or column). Its mode of deflection is primarily by bending , as loads produce reaction forces at the beam's support points and internal bending moments , shear , stresses , strains , and deflections . Beams are characterized by their manner of support, profile (shape of cross-section), equilibrium conditions, length, and material. Beams are traditionally descriptions of building or civil engineering structural elements, where

108-404: A single beam. A grid deck uses beams and diaphragms as the supporting structure. The supporting system of a grid deck is analyzed using a grillage analysis. A slab deck is one where the deck is analyzed as a plate. If the slab has a stiffness that is different in two directions (at right angles), then the deck is known and analyzed as an orthotropic deck . A beam and slab deck is one where

135-508: Is 591 feet (180 m) long and crosses the Cuyahoga River. The steel span cost $ 646,747. About 2,123,300 cubic yards (1,623,400 m) of concrete and 9,385,000 pounds (4,257,000 kg) of reinforcing steel were used in the construction of the arches. The concrete piles used in the foundation work, if placed end to end, would extend a distance of 28 miles (45 km). Each end of the structure has underground streetcar stations for

162-573: Is a box (a square shell); the most efficient shape for bending in any direction, however, is a cylindrical shell or tube. For unidirectional bending, the Ɪ-beam or wide flange beam is superior. Efficiency means that for the same cross sectional area (volume of beam per length) subjected to the same loading conditions, the beam deflects less. Other shapes, like L-beam (angles), C (channels) , T-beam and double-T or tubes, are also used in construction when there are special requirements. This system provides horizontal bracing for small trenches, ensuring

189-431: Is called an open deck . When the track rests upon ballast , which is then carried by the superstructure of the bridge, it is called a ballasted deck . The term direct fixation is used when the rails are anchored directly to the superstructure of the bridge. Beam (structure) A beam is a structural element that primarily resists loads applied laterally across the beam's axis (an element designed to carry

216-488: Is much higher than that for solid cross sections such a rod or bar. In this way, stiff beams can be achieved with minimum weight. Thin walled beams are particularly useful when the material is a composite laminate . Pioneer work on composite laminate thin walled beams was done by Librescu . The torsional stiffness of a beam is greatly influenced by its cross sectional shape. For open sections, such as I sections, warping deflections occur which, if restrained, greatly increase

243-531: The deflection of beams include "method of virtual work " and the "slope deflection method". Engineers are interested in determining deflections because the beam may be in direct contact with a brittle material such as glass . Beam deflections are also minimized for aesthetic reasons. A visibly sagging beam, even if structurally safe, is unsightly and to be avoided. A stiffer beam (high modulus of elasticity and/or one of higher second moment of area ) creates less deflection. Mathematical methods for determining

270-444: The parallel axis theorem and the fact that most of the material is away from the neutral axis , the second moment of area of the beam increases, which in turn increases the stiffness. An Ɪ-beam is only the most efficient shape in one direction of bending: up and down looking at the profile as an 'Ɪ'. If the beam is bent side to side, it functions as an 'H', where it is less efficient. The most efficient shape for both directions in 2D

297-521: The Cleveland Ingenuity Festival. Self-guided tours are free of charge. Deck (bridge) A deck is the surface of a bridge . A structural element of its superstructure , it may be constructed of concrete , steel , open grating , or wood. Sometimes the deck is covered by a railroad bed and track , asphalt concrete , or other form of pavement for ease of vehicle crossing. A concrete deck may be an integral part of

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324-424: The beam forces (internal forces of the beam and the forces that are imposed on the beam support) include the " moment distribution method ", the force or flexibility method and the direct stiffness method . Most beams in reinforced concrete buildings have rectangular cross sections, but a more efficient cross section for a beam is an Ɪ- or H-shaped section which is typically seen in steel construction. Because of

351-415: The beam is exposed to shear stress. There are some reinforced concrete beams in which the concrete is entirely in compression with tensile forces taken by steel tendons. These beams are known as prestressed concrete beams, and are fabricated to produce a compression more than the expected tension under loading conditions. High strength steel tendons are stretched while the beam is cast over them. Then, when

378-416: The beams are horizontal and carry vertical loads. However, any structure may contain beams, such as automobile frames, aircraft components, machine frames, and other mechanical or structural systems. Any structural element , in any orientation, that primarily resists loads applied laterally across the element's axis is a beam. Historically a beam is a squared timber, but may also be made of metal, stone, or

405-439: The beams may deflect somewhat independently, and any transverse forces are carried in the deck. A cellular deck is one where a number of thin slabs and webs will enclose cells within the deck. A boxgirder deck is one where the deck forms the top of the box girder during analysis. A railway bridge with its track and ties supported on load carrying elements of the superstructure (floor beams , stringers or girders )

432-411: The bottom to enclose an arc of larger radius in tension. This is known as sagging ; while a configuration with the top in tension, for example over a support, is known as hogging . The axis of the beam retaining its original length, generally halfway between the top and bottom, is under neither compression nor tension, and defines the neutral axis (dotted line in the beam figure). Above the supports,

459-468: The bridge structure ( T-beam or double tee structure) or it may be supported with I-beams or steel girders . When a bridge deck is installed in a through truss , it is sometimes called a floor system. A suspended bridge deck will be suspended from the main structural elements on a suspension or arch bridge. On some bridges, such as a tied-arch or a cable-stayed , the deck is a primary structural element , carrying tension or compression to support

486-554: The bridge was renamed the Veterans Memorial Bridge. It was added to the National Register of Historic Places on January 18, 1974. In 2003, Cuyahoga County Commissioners approved the conversion of the two outside traffic lanes for pedestrian and bicycle use. The lower level and subway station are opened to the public for tours a few times per year, typically around Memorial Day , Labor Day , and for

513-462: The closure of the streetcar operations, the subway level became unused. In November 1955, ramps to the lower level were closed. The Detroit–Superior Bridge remained a bottleneck during rush hour. A two-year renovation completed in May 1969 added two traffic lanes by narrowing existing sidewalks from 15 to 5 feet and cantilevering the new lanes outside the central arch. On November 11, 1989 ( Veterans Day ),

540-472: The concrete has cured, the tendons are slowly released and the beam is immediately under eccentric axial loads. This eccentric loading creates an internal moment, and, in turn, increases the moment-carrying capacity of the beam. Prestressed beams are commonly used on highway bridges. The primary tool for structural analysis of beams is the Euler–Bernoulli beam equation . This equation accurately describes

567-555: The elastic behaviour of slender beams where the cross sectional dimensions are small compared to the length of the beam. For beams that are not slender a different theory needs to be adopted to account for the deformation due to shear forces and, in dynamic cases, the rotary inertia. The beam formulation adopted here is that of Timoshenko and comparative examples can be found in NAFEMS Benchmark Challenge Number 7. Other mathematical methods for determining

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594-412: The ground. In light frame construction , joists may rest on beams. In engineering, beams are of several types: In the beam equation , the variable I represents the second moment of area or moment of inertia : it is the sum, along the axis, of dA · r , where r is the distance from the neutral axis and dA is a small patch of area. It measures not only the total area of the beam section, but

621-506: The river, and rises to 196 feet (60 m) above the river at the peak of the central span. The original construction included a main deck 75 feet (23 m) wide, with two 15 feet (4.6 m) sidewalks and a 45 feet (14 m) roadway. While the bridge's upper level is for road traffic, the lower level was intended for streetcars . It was built with four sets of these tracks, leaving room for two more, if needed. The structure includes 12 concrete arches and one steel span. The steel span

648-555: The secure installation of utilities. It's specifically designed to work in conjunction with steel trench sheets. A thin walled beam is a very useful type of beam (structure). The cross section of thin walled beams is made up from thin panels connected among themselves to create closed or open cross sections of a beam (structure). Typical closed sections include round, square, and rectangular tubes. Open sections include I-beams, T-beams, L-beams, and so on. Thin walled beams exist because their bending stiffness per unit cross sectional area

675-432: The span. A deck bridge is one in which the deck itself is the main structural element, itself carrying the roadway. Contrast to a truss bridge which may carry a deck on the top chords or bottom chords of a structural truss . Structural engineers have several principal categories of bridge decks, for the purposes of analytic techniques. A beam deck is one where the deck and any supporting structure act together as

702-438: The square of each patch's distance from the axis. A larger value of I indicates a stiffer beam, more resistant to bending. Loads on a beam induce internal compressive , tensile and shear stresses (assuming no torsion or axial loading). Typically, under gravity loads, the beam bends into a slightly circular arc, with its original length compressed at the top to form an arc of smaller radius, while correspondingly stretched at

729-496: The trams that operated on the lower deck. The Detroit–Superior subway was an underground transit system that operated between 1917 until its closure January 24, 1954. The line served riders between Cleveland's west side and downtown . The system had two stations: West 25th (four platforms) and West 9th (two platforms), which included restrooms. The line ran on the lower level of the Detroit–Superior Bridge. Due to

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