Washington Crossing Bridge (Pittsburgh)
The Washington Crossing Bridge known as the Fortieth Street Bridge, is an arch bridge that carries vehicular traffic across the Allegheny River between the Pittsburgh neighborhood of Lawrenceville and the suburb of Millvale. The bridge was built to accommodate two lanes of traffic and one streetcar line; the bridge received its name because it is located at a significant site pertaining to George Washington's military career. In 1753, then-Major Washington was dispatched to give French forces an ultimatum to negotiate for the return of the lands that today make up Western Pennsylvania to the British or to prepare for a military strike. Crossing the Allegheny on a wooden raft, Washington was nearly killed when his vessel overturned at this site. List of bridges documented by the Historic American Engineering Record in Pennsylvania List of crossings of the Allegheny River Historic American Buildings Survey No. PA-1179, "Washington Crossing Bridge, Fortieth Street, Allegheny County, PA", 14 measured drawings Historic American Engineering Record No.
PA-447, "Washington Crossing Bridge"
Fifth Avenue (Pittsburgh)
Fifth Avenue is one of the longest streets in Pittsburgh, United States. It begins downtown and moves eastward for over five miles. Fifth Avenue passes by the Carlow University, the Cathedral of Learning and other buildings of the University of Pittsburgh forms the borders between Shadyside on the north and Squirrel Hill and Point Breeze to the south. After passing Chatham University, The Ellis School, Mellon Park, it turns north and forms the border between Larimer on the west and North Point Breeze and Homewood on the east. At the intersection with Frankstown Avenue its name becomes Washington Boulevard and descends a branch of Negley Run to meet Allegheny River Boulevard near the Highland Park Bridge. At least 30 streets either cross or intersect with Fifth Avenue, including Penn Avenue, which intersects it twice. Forbes Avenue parallels it from Downtown through Uptown and Oakland before diverging at the University of Pittsburgh.
Fort Duquesne Bridge
The Fort Duquesne Bridge is a steel bowstring arch bridge that spans the Allegheny River in Pittsburgh, Pennsylvania. It was colloquially referred to as "The Bridge to Nowhere", it was constructed from 1958-1963 by PennDOT, opened for traffic October 17, 1969 with its predecessor Manchester Bridge closing that same day. The bridge was given the name "The Bridge to Nowhere" because the main span was finished in 1963, but due to delays in acquiring right of ways for the northern approach ramps, it did not connect on the north side of the Allegheny River; the total cost was budgeted at $5 million in 1962. The lack of approach ramps meant; the northwestern ramps were completed in 1969, allowing access to Pennsylvania Route 65. The northeastern ramps were completed in 1986, with the construction of the northern section of Interstate 279 which runs through Downtown Pittsburgh's Golden Triangle and north towards Interstate 79; the bridge touches down halfway between Heinz Field and PNC Park Baseball Stadium on the City's North Shore.
On December 12, 1964, Frederick Williams, a 21-year-old chemistry major at the University of Pittsburgh from Basking Ridge, New Jersey, drove his 1959 Chrysler station wagon through the bridge's wooden barricades, raced off the end of the bridge, landed upside-down but unhurt on the other side, 190 feet away at the north bank of the Allegheny River. His adventure is documented in WQED-TV's double Mid-Atlantic region Emmy Award-winning documentary "Flying off the Bridge to Nowhere and Other Tales of Pittsburgh Bridges", narrated by Rick Sebak. Within a few weeks of this near tragedy, an iconic Pittsburgh radio personality, Rege Cordic, distributed commemorative bumper stickers which read "Official Entry, Cordic & Company Bridge Leap Contest." With thousands of vehicles bearing these stickers on Pittsburgh's streets, the city responded by blocking off the end of the bridge with concrete barriers. List of crossings of the Allegheny River Fort Duquesne Bridge at Pghbridges.com
Forbes Avenue is one of the longest streets in Pittsburgh, United States. It has a length of about ten miles and is named for John Forbes, whose expedition recaptured Fort Duquesne and who renamed the place Pittsburgh in 1758; the westernmost terminus of Forbes Avenue lies at Stanwix Street in the downtown part of the city runs eastward past PPG Place, directly through Market Square and between the Courthouse and the City-County Building, past Duquesne University, through Uptown, Oakland where it passes the University of Pittsburgh's Cathedral of Learning and the Carnegie Library of Pittsburgh. From Oakland, Forbes Avenue continues eastward past Carnegie Mellon University and Schenley Park, through the neighborhood of Squirrel Hill, past Homewood Cemetery and Frick Park before it reaches its eastern terminus at Wilkinsburg
Pennsylvania the Commonwealth of Pennsylvania, is a state located in the northeastern and Mid-Atlantic regions of the United States. The Appalachian Mountains run through its middle; the Commonwealth is bordered by Delaware to the southeast, Maryland to the south, West Virginia to the southwest, Ohio to the west, Lake Erie and the Canadian province of Ontario to the northwest, New York to the north, New Jersey to the east. Pennsylvania is the 33rd-largest state by area, the 6th-most populous state according to the most recent official U. S. Census count in 2010, it is the 9th-most densely populated of the 50 states. Pennsylvania's two most populous cities are Philadelphia, Pittsburgh; the state capital and its 10th largest city is Harrisburg. Pennsylvania has 140 miles of waterfront along the Delaware Estuary; the state is one of the 13 original founding states of the United States. Part of Pennsylvania, together with the present State of Delaware, had earlier been organized as the Colony of New Sweden.
It was the second state to ratify the United States Constitution, on December 12, 1787. Independence Hall, where the United States Declaration of Independence and United States Constitution were drafted, is located in the state's largest city of Philadelphia. During the American Civil War, the Battle of Gettysburg was fought in the south central region of the state. Valley Forge near Philadelphia was General Washington's headquarters during the bitter winter of 1777–78. Pennsylvania is 170 miles north to south and 283 miles east to west. Of a total 46,055 square miles, 44,817 square miles are land, 490 square miles are inland waters, 749 square miles are waters in Lake Erie, it is the 33rd-largest state in the United States. Pennsylvania has 51 miles of coastline along Lake Erie and 57 miles of shoreline along the Delaware Estuary. Of the original Thirteen Colonies, Pennsylvania is the only state that does not border the Atlantic Ocean; the boundaries of the state are the Mason–Dixon line to the south, the Twelve-Mile Circle on the Pennsylvania-Delaware border, the Delaware River to the east, 80° 31' W to the west and the 42° N to the north, with the exception of a short segment on the western end, where a triangle extends north to Lake Erie.
Cities include Philadelphia, Reading and Lancaster in the southeast, Pittsburgh in the southwest, the tri-cities of Allentown and Easton in the central east. The northeast includes the former anthracite coal mining cities of Scranton, Wilkes-Barre and Hazleton. Erie is located in the northwest. State College serves the central region while Williamsport serves the commonwealth's north-central region as does Chambersburg the south-central region, with York and the state capital Harrisburg on the Susquehanna River in the east-central region of the Commonwealth and Altoona and Johnstown in the west-central region; the state has five geographical regions, namely the Allegheny Plateau and Valley, Atlantic Coastal Plain and the Erie Plain. New York Ontario Maryland Delaware West Virginia New Jersey Ohio Pennsylvania's diverse topography produces a variety of climates, though the entire state experiences cold winters and humid summers. Straddling two major zones, the majority of the state, with the exception of the southeastern corner, has a humid continental climate.
The southern portion of the state has a humid subtropical climate. The largest city, has some characteristics of the humid subtropical climate that covers much of Delaware and Maryland to the south. Summers are hot and humid. Moving toward the mountainous interior of the state, the winter climate becomes colder, the number of cloudy days increases, snowfall amounts are greater. Western areas of the state locations near Lake Erie, can receive over 100 inches of snowfall annually, the entire state receives plentiful precipitation throughout the year; the state may be subject to severe weather from spring through summer into fall. Tornadoes occur annually in the state, sometimes in large numbers, such as 30 recorded tornadoes in 2011; as of 1600, the tribes living in Pennsylvania were the Algonquian Lenape, the Iroquoian Susquehannock & Petun and the Siouan Monongahela Culture, who may have been the same as a little known tribe called the Calicua, or Cali. Other tribes who entered the region during the colonial era were the Trockwae, Saponi, Nanticoke, Conoy Piscataway, Iroquois Confederacy—possibly among others.
Other tribes, like the Erie, may have once held some land in Pennsylvania, but no longer did so by the year 1600. Both the Dutch and the English claimed both sides of the Delaware River as part of their colonial lands in America; the Dutch were the first to take possession. By June 3, 1631, the Dutch had begun settling the Delmarva Peninsula by establishing the Zwaanendael Colony on the site of present-day Lewes, Delaware. In 1638, Sweden established the New Sweden Colony, in the region of Fort Christina, on the site of present-day Wilmington, Delaware. New Sweden claimed and, for the most part, controlled the lower Delaware River region (parts of present-day Delaware, New Jersey, Pe
The Liberty Tunnels are a pair of tunnels located in Pittsburgh, Pennsylvania that allow motorists to travel between the South Hills of Pittsburgh and the city, beneath Mt. Washington; the tunnels were vital in the expansion of the South Hills suburbs by providing a direct route to the city, eliminating the time-consuming task of navigating around or over Mt. Washington and its inclines. Opening in 1924, the Liberty Tunnels are the longest automobile tunnel in the City of Pittsburgh; the tunnels were designed by Amos D. Neeld, who would supervise the construction of the adjoining Liberty Bridge, which gives travelers a way to cross the Monongahela River after passing through the tunnels; the design was two vertical wall horseshoe profile tunnels, each consisting of two lanes of traffic and a 4 ft sidewalk. The sidewalks, being minimally used and in disrepair, were removed during a renovation in the 1970s in order to widen and increase the height of the traffic lanes. Prior to the construction of the Liberty Tunnels, many other projects were proposed.
One plan, from engineer W. M. Donley, called for a deep cut through the mountain; this would eliminate the need for a tunnel. Many residents wanted tunnels to be built in Shalerville. In 1959, the Fort Pitt Tunnels were constructed near this proposed area. Other residents wanted tunnels to be built in a valley behind Mt. Washington that led to Dormont and Mt. Lebanon, they would follow a low line to exit at Saw Mill Run. This was known as the Bell Tavern plan, modified to create the Liberty Tunnels; the final plan for the tunnels shared the southern Bell Tavern portal, but followed a higher line to emerge on the north face of Mt. Washington; this plan required the construction of a new bridge, to become the Liberty Bridge. Booth and Flinn, Ltd. were awarded the contract to build the new tunnels in January 1919, construction began shortly thereafter. On May 11, 1922, the boring of the tunnels was complete and in January 1924, the $6 million Liberty Tunnels were opened to traffic. However, the tunnels were not yet complete and lacked a major component necessary to the project: ventilation.
There was not yet a ventilation system when the tunnels opened, but authorities decided the flow of traffic would allow for a natural draft of ventilation. On May 10, 1924, a traffic jam which occurred due to a Pittsburgh Street Railway Company strike, causing vehicles to be stopped, idling in the tunnels. Several motorists passed out from the fumes emitted from the exhaust of the congested vehicles. For the safety of motorists, the number of vehicles permitted through the tunnels was regulated until a ventilation system was installed. With help from the U. S. Bureau of Mines, tunnel engineers designed a system to ventilate the tunnels to accommodate the high traffic flow. In 1928, construction of four 200-foot vertical shafts was completed to continuously provide fresh air to the tunnels. A plant located on top on the mountain was constructed to pump the fresh air through the shafts, which tower 110 ft above the plant. After the ventilation system was put into service, the traffic restrictions were lifted.
Following the completion of the Liberty Tunnels, the Liberty Bridge was completed and linked to the tunnels on March 27, 1928. The bridge and tunnel combination gave motorists and pedestrians a direct route to the city without traveling over or around Mt. Washington. 5,889 ft in length Twin tunnels 2 lanes in each tunnel Vertical wall horseshoe profile 11 cross passages 14 ft 6 in posted vertical clearance Each tunnel is 28.6 ft wide and 20.75 ft high to arch Floor slopes upward 0.329 percent grade to Saw Mill Run portal 20 ft higher Opened in 1924 Between: Liberty Bridge. Since August 1987 the tunnels have provided cellular phone reception. Liberty Tunnels on pghbridges.com
A tied-arch bridge is an arch bridge in which the outward-directed horizontal forces of the arch are borne as tension by a chord tying the arch ends, rather than by the ground or the bridge foundations. This strengthened chord may be the deck structure itself or consist of separate, deck-independent tie-rods. Thrusts downwards on a tied-arch bridge deck are translated, as tension, by vertical ties between the deck and the arch, tending to flatten it and thereby to push its tips outward into the abutments, like for other arch bridges. However, in a tied-arch or bowstring bridge, these movements are restrained not by the abutments but by the strengthened chord, which ties these tips together, taking the thrusts as tension, rather like the string of a bow, being flattened. Therefore, the design is called a bowstring-arch or bowstring-girder bridge; the elimination of horizontal forces at the abutments allows tied-arch bridges to be constructed with less robust foundations. In addition, since they do not depend on horizontal compression forces for their integrity, tied-arch bridges can be prefabricated offsite, subsequently floated, hauled or lifted into place.
Notable bridges of this type include the Fremont Bridge in Portland, Oregon as well as the first "computer designed" bridge of this type the Fort Pitt Bridge in Pittsburgh, Pennsylvania. Both the tied-arch bridge and the self-anchored suspension bridge place only vertical loads on the anchorage, so are suitable where large horizontal forces are difficult to anchor; some tied-arch bridges only tie a segment of the main arch directly and prolong the strengthened chord to tie to the top ends of auxiliary arches. The latter support the deck from below and join their bottom feet to those of the main arch; the supporting piers at this point may be slender, because the outward-directed horizontal forces of main and auxiliary arch ends counterbalance. The whole structure is self-anchored. Like the simple case it places vertical loads on all ground-bound supports. An example is the Fremont Bridge in Portland, Oregon, the second-longest tied-arch bridge in the world and classifies as a through arch bridge.
The Chaotianmen Bridge in Chongqing is a tied-arch, through a truss arch bridge. Contrarily, the Hart Bridge uses a cantilevered trussed arch, it is self-anchored, but its arch is non-tied. In particular the bridge deck does not tie the arch ends. Tied arch bridges may consist of successively lined up tied arches in places where a single span is not sufficient. An example for this is the Godavari Arch Bridge in India, it carries the South Central Railway Line of India. It was designed for 250 km/h rail services. Like for multi-span continuous beam bridges the tying chord continually spans over all piers; the arches feet coincide at the bridge piers. A good visual indication are shared supports at the piers. Dynamic loads are distributed between spans; this type may be combined with the shouldered tied-arch design discussed above. An example for this is Dashengguan Bridge in China, its two main arches are shouldered by short auxiliary arches. It is a tied-arch and a cantilevered trussed arch design; because the traffic runs through the structural envelope, it is a through arch bridge.
Guandu Bridge in New Taipei, Taiwan is a non-trussed example with three main arches augmented by two auxiliary arch segments at the bridge portals. The Infinity Bridge uses two arches of different height and span length that both bifurcate before their apex. Above its single, middle-displaced river pier the deck lies between the arches. Contrarily each abutment on the riverbanks supports a single arch end only, in the middle of the deck; the tying chord consist of a composite deck structure. Four post tensioned coil steel cables, two to each side of the walking deck, are locked in place by orthogonally run steel beams every 7.5 meters. The hangers are joined to each of these beams between each cable pair. Since the beams extend the width of the post-tensioned concrete deck, the tensing cable pairs remain visible. A close-up of the river pier shows that the structural dead load is tied per span: The larger arch span uses thicker tensing cables and the reflex segments are not suspended from, but supported by steel beams completing the arches at the river pier.
However, for dynamic and non-uniform loads the visually defining arch continuations must not be neglected. For a single span, two tied-arches are placed in parallel alongside the deck, so the deck lies in between the arches. Axial tied-arch or single tied-arch bridges have at most one tied-arch per span, centered in the middle of the bridge deck. An example for this is Hoge Brug in Maastricht. Since it has hinged hangers it might classify as a Nielsen bridge who held a patent on tied-arch bridges with hinged hangers from 1926; some designs tilt the arches outward or inward with respect to the axis running along the bridge deck. In analogy to twin bridges, two tied arch bridges erected side by side to increase traffic capacity, but structurally independent, may be referred to by tied arch twin bridges; each in return may use a discrete or continuous tied-arch design. A bowstring truss bridge is similar in appearance to a tied-arch; the visual distinction is a tied-arch bridge will not have substantial diagonal members between the vertical members.
In a 1978 advisory issued by the Federal Highway Administration, the FHWA noted that tied-arch bridges are susceptible to problems caused by poor welds at the connection betw