|
Pin And Hanger Assembly
A pin and hanger assembly is used to connect two plate girders of a bridge. These assemblies are used to provide an expansion joint in the bridge. One beam (the ''anchor span'') is set on a pier with a short section cantilevered out toward the next pier. The other (the ''suspended span'') begins underneath the anchor span, and has its far end resting on the next pier. The beams have holes directly above each other. The two holes are connected using ''hangers'', a pair of connecting plates sandwiching the bridge girders. A pair of large steel pins through the plates and girder webbing provide the hinges, holding up the suspended span while allowing it to move longitudinally. Large washers are bolted to each end of the pin to retain the hangers. Exceptionally long spans may have two sets of girders cantilevered from opposite bridge piers with a third set of girders suspended by pin and hanger assemblies from both cantilevers. Safety concerns Pin and hanger assemblies are co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plate Girder Bridge
A plate girder bridge is a bridge supported by two or more plate girders. Overview In a plate girder bridge, the plate girders are typically I-beams made up from separate structural steel plates (rather than rolled as a single cross-section), which are welded or, in older bridges, bolted or riveted together to form the vertical web and horizontal flanges of the beam. In some cases, the plate girders may be formed in a Z-shape rather than I-shape. The first tubular wrought iron plate girder bridge was built in 1846-47 by James Millholland for the Baltimore and Ohio Railroad. Plate girder bridges are suitable for short to medium spans and may support railroads, highways, or other traffic. Plate girders are usually prefabricated and the length limit is frequently set by the mode of transportation used to move the girder from the bridge shop to the bridge site. Generally, the depth of the girder is no less than the span, and for a given load bearing capacity, a depth of around ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expansion Joint
An expansion joint, or movement joint, is an assembly designed to hold parts together while safely absorbing temperature-induced expansion and contraction of building materials, and vibration, or to allow movement due to ground settlement or seismic activity. They are commonly found between sections of buildings, bridges, sidewalks, railway tracks, piping systems, ships, and other structures. Building faces, concrete slabs, and pipelines expand and contract due to warming and cooling from seasonal variation, or due to other heat sources. Before expansion joint gaps were built into these structures, they would crack under the stress induced. Bridge expansion joints Bridge expansion joints are designed to allow for continuous traffic between structures while accommodating movement, shrinkage, and temperature variations on reinforced and prestressed concrete, composite, and steel structures. They stop the bridge from bending out of place in extreme conditions, and also allow eno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cantilever
A cantilever is a rigid structural element that extends horizontally and is supported at only one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cantilever can be formed as a beam, plate, truss, or slab. When subjected to a structural load at its far, unsupported end, the cantilever carries the load to the support where it applies a shear stress and a bending moment. Cantilever construction allows overhanging structures without additional support. In bridges, towers, and buildings Cantilevers are widely found in construction, notably in cantilever bridges and balconies (see corbel). In cantilever bridges, the cantilevers are usually built as pairs, with each cantilever used to support one end of a central section. The Forth Bridge in Scotland is an example of a cantilever truss bridge. A cantilever in a traditionally timber framed building is called a jetty or forebay. In the southe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fracture Mechanics
Fracture mechanics is the field of mechanics concerned with the study of the propagation of cracks in materials. It uses methods of analytical solid mechanics to calculate the driving force on a crack and those of experimental solid mechanics to characterize the material's resistance to fracture. Theoretically, the stress ahead of a sharp crack tip becomes infinite and cannot be used to describe the state around a crack. Fracture mechanics is used to characterise the loads on a crack, typically using a single parameter to describe the complete loading state at the crack tip. A number of different parameters have been developed. When the plastic zone at the tip of the crack is small relative to the crack length the stress state at the crack tip is the result of elastic forces within the material and is termed linear elastic fracture mechanics (LEFM) and can be characterised using the stress intensity factor K. Although the load on a crack can be arbitrary, in 1957 G. Irwin foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mianus River Bridge
The Mianus River Bridge is a span that carries Interstate 95 (Connecticut Turnpike) over the Mianus River, between Cos Cob and Riverside, Connecticut. It is the second bridge on the site. The original bridge collapsed in 1983, killing three motorists. The replacement span is officially named the Michael L. Morano Bridge, after a state senator Michael L. Morano who represented Greenwich. Collapse The bridge had a 100-foot (30.5 m) section of its deck of its northbound span collapse on June 28, 1983. Three people were killed and three more were seriously injured when two cars and two tractor-trailers fell with the bridge into the Mianus River 70 feet (21.3 m) below. Casualties from the collapse were few because the disaster occurred at 1:30 a.m., when traffic was low on the often-crowded highway. Causes The collapse was caused by the failure of two pin and hanger assemblies that held the deck in place on the outer side of the bridge, according to an investigation by the N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Connecticut
Connecticut () is the southernmost state in the New England region of the Northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, New York to the west, and Long Island Sound to the south. Its capital is Hartford and its most populous city is Bridgeport. Historically the state is part of New England as well as the tri-state area with New York and New Jersey. The state is named for the Connecticut River which approximately bisects the state. The word "Connecticut" is derived from various anglicized spellings of "Quinnetuket”, a Mohegan-Pequot word for "long tidal river". Connecticut's first European settlers were Dutchmen who established a small, short-lived settlement called House of Hope in Hartford at the confluence of the Park and Connecticut Rivers. Half of Connecticut was initially claimed by the Dutch colony New Netherland, which included much of the land between the Connecticut and Delaware Rivers, although the firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tie Rod
A tie rod or tie bar (also known as a hanger rod if vertical) is a slender structural unit used as a tie and (in most applications) capable of carrying tensile loads only. It is any rod or bar-shaped structural member designed to prevent the separation of two parts, as in a vehicle. Subtypes and examples of applications * In airplane structures, tie rods are sometimes used in the fuselage or wings. * Tie rods are often used in steel structures, such as bridges, industrial buildings, tanks, towers, and cranes. * Sometimes tie rods are retrofitted to bowing or subsiding masonry walls (brick, block, stone, etc.) to keep them from succumbing to lateral forces. * The rebar used in reinforced concrete is not referred to as a "tie rod", but it essentially performs some of the same tension-force-counteracting purposes that tie rods perform. * In automobiles, the ''tie rods'' are part of the steering mechanism. They differ from the archetypal tie rod by both pushing and pulling (operatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gusset Plates
Gusset plate is a plate for connecting beams and girders to columns. A gusset plate can be fastened to a permanent member either by bolts, rivets or welding or a combination of the three. They are used in bridges and buildings, as well as other structures. Materials Gusset plates are usually either made from cold-rolled or galvanized steel, based upon their use. Galvanized steel offers more protection from rust, so this is usually used when the gusset plate is exposed to the elements. The gusset plate is usually painted to match nearby steel and fixtures and to give it an extra layer of protection. Occasionally gusset plates are made from copper or aluminum, but only with small structures that do not require much support. The copper and aluminum gusset plates also provide a more attractive finish for exposed structures. Uses Gusset plates are used for various structures. Gusset plates are used to connect beams and columns together or to connect truss members. They can be ei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
