Empire State Building

History: Empire State Building
U.S. National Register of Historic Places
U.S. National Historic Landmark
NYC Landmark
Location: 350 Fifth Avenue, New York, New York 10118, United States
Coordinates:
404454.36 735908.36 / 40.7484333N 73.9856556W / 40.7484333; -73.9856556Coordinates: 404454.36 735908.36 / 40.7484333N 73.9856556W / 40.7484333; -73.9856556
Architect:  Shreve, Lamb and Harmon
Architectural style(s):  Art Deco
Added to NRHP:  November 17, 1982
Designated NHL:  June 24, 1986
Designated NYCL:  May 19, 1981
NRHP Reference#: 82001192 

The site of the Empire State Building was first developed as the John Thomson Farm in the late 18th century. At the time, a stream ran across the site, emptying into Sunfish Pond, located a block away. Beginning in the late 19th century the block was occupied by the Waldorf-Astoria Hotel, frequented by The Four Hundred, the social elite of New York.

Design and construction

The Empire State Building was designed by William F. Lamb from the architectural firm Shreve, Lamb and Harmon, which produced the building drawings in just two weeks, using its earlier designs for the Reynolds Building in Winston-Salem, North Carolina, and the Carew Tower in Cincinnati, Ohio (designed by the architectural firm W.W. Ahlschlager & Associates) as a basis. Every year the staff of the Empire State Building sends a Father's Day card to the staff at the Reynolds Building in Winston-Salem to pay homage to its role as predecessor to the Empire State Building. The building was designed from the top down. The general contractors were The Starrett Brothers and Eken, and the project was financed primarily by John J. Raskob and Pierre S. du Pont. The construction company was chaired by Alfred E. Smith, a former Governor of New York and James Farley's General Builders Supply Corporation supplied the building materials. John W. Bowser was project construction superintendant.

Excavation of the site began on January 22, 1930, and construction on the building itself started symbolically on March 17t.Patrick's Dayer Al Smith's influence as Empire State, Inc. president. The project involved 3,400 workers, mostly immigrants from Europe, along with hundreds of Mohawk iron workers, many from the Kahnawake reserve near Montreal. According to official accounts, five workers died during the construction. Governor Smith's grandchildren cut the ribbon on May 1, 1931. Lewis Wickes Hine's photography of the construction provides not only invaluable documentation of the construction, but also a glimpse into common day life of workers in that era. In particular the photo of a worker climbing a stay cable is talismanic of the era and the building itself.

The construction was part of an intense competition in New York for the title of "world's tallest building". Two other projects fighting for the title, 40 Wall Street and the Chrysler Building, were still under construction when work began on the Empire State Building. Each held the title for less than a year, as the Empire State Building surpassed them upon its completion, just 410 days after construction commenced. The building was officially opened on May 1, 1931 in dramatic fashion, when United States President Herbert Hoover turned on the building's lights with the push of a button from Washington, D.C. Ironically, the first use of tower lights atop the Empire State Building, the following year, was for the purpose of signalling the victory of Franklin D. Roosevelt over Hoover in the presidential election of November 1932.

Opening

The building's opening coincided with the Great Depression in the United States, and as a result much of its office space went without being rented. The building's vacancy was exacerbated by its poor location on 34th Street, which placed it relatively far from public transportation, as Grand Central Terminal, the Port Authority Bus Terminal, and Penn Station are all several blocks away. Other more successful skyscrapers, such as the Chrysler Building, do not have this problem. In its first year of operation, the observation deck took in approximately 2 million dollars, as much money as its owners made in rent that year. The lack of renters led New Yorkers to deride the building as the "Empty State Building". The building would not become profitable until 1950. The famous 1951 sale of The Empire State Building to Roger L. Stevens and his business partners was brokered by the prominent upper Manhattan real-estate firm Charles F. Noyes & Company for a record $51 million. At the time, that was the highest price ever paid for a single structure in real-estate history.

Dirigible (airship) terminal

The building's distinctive Art Deco spire was originally designed to be a mooring mast and depot for dirigibles. The 102nd floor was originally a landing platform with a dirigible gangplank. A particular elevator, traveling between the 86th and 102nd floors, was supposed to transport passengers after they checked in at the observation deck on the 86th floor. However, the idea proved to be impractical and dangerous after a few attempts with airships, due to the powerful updrafts caused by the size of the building itself. A large broadcast tower was added to the top of the spire in 1953.

1945 plane crash

Crash by a U.S. Army B-25 bomber on July 28, 1945

At 9:40 a.m.on Saturday, July 28, 1945, a B-25 Mitchell bomber, piloted in thick fog by Lieutenant Colonel William Franklin Smith, Jr., crashed into the north side of the Empire State Building, between the 79th and 80th floors, where the offices of the National Catholic Welfare Council were located. One engine shot through the side opposite the impact and flew as far as the next block where it landed on the roof of a nearby building, starting a fire that destroyed a penthouse. The other engine and part of the landing gear plummeted down an elevator shaft. The resulting fire was extinguished in 40 minutes. 14 people were killed in the incident. Elevator operator Betty Lou Oliver survived a plunge of 75 stories inside an elevator, which still stands as the Guinness World Record for the longest survived elevator fall recorded. Despite the damage and loss of life, the building was open for business on many floors on the following Monday. The crash helped spur the passage of the long-pending Federal Tort Claims Act of 1946, as well as the insertion of retroactive provisions into the law, allowing people to sue the government for the accident.

A year later, another aircraft had a close encounter with the skyscraper. It narrowly missed striking the building.

Height records and comparisons
 
Height comparison in buildings in New York City

The Empire State Building remained the tallest man-made structure in the world for 23 years before it was surpassed by the Griffin Television Tower Oklahoma (KWTV Mast) in 1954. It was also the tallest free-standing structure in the world for 36 years before it was surpassed by the Ostankino Tower in 1967.

The longest world record held by the Empire State Building was for the tallest skyscraper (to structural height), which it held for 42 years until it was surpassed by the North Tower of the World Trade Center in 1973. With the destruction of the World Trade Center in the September 11, 2001 attacks, the Empire State Building again became the tallest building in New York City, and the second-tallest building in the Americas, currently surpassed only by the Willis Tower in Chicago. When measured by pinnacle height, the Empire State Building is currently the third-tallest building in the Americas, surpassed only by the Willis Tower and the Trump International Hotel and Tower.

World Trade Center, currently under construction in New York City, is expected to exceed the height of the Empire State Building upon completion. The Chicago Spire is also expected to exceed the height of the Empire State Building upon completion, but its construction has been halted due to financial problems.

Suicides

Over the years, more than thirty people have committed suicide from the top of the building. The first suicide occurred even before its completion, by a worker who had been laid off. The fence around the observatory terrace was put up in 1947 after five people tried to jump during a three-week span. On December 2, 1979, Elvita Adams jumped from the 86th floor, only to be blown back onto the 85th floor and left with only a broken hip.

Shootings

On February 24, 1997, a Palestinian gunman shot seven people on the observation deck, killing one, then fatally wounding himself.

Architecture

The Empire State Building (in center of image) is the tallest building in New York City. The Empire State Building rises to 1,250 ft (381 m) at the 102nd floor, and including the 203 ft (62 m) pinnacle, its full height reaches 1,453 ft8916 in (443.09 m). The building has 85 stories of commercial and office space representing 2,158,000 sq ft (200,500 m2). It has an indoor and outdoor observation deck on the 86th floor. The remaining 16 stories represent the Art Deco tower, which is capped by a 102nd-floor observatory. Atop the tower is the 203 ft (62 m) pinnacle, much of which is covered by broadcast antennas, with a lightning rod at the very top.

The Empire State Building was the first building to have more than 100 floors. It has 6,500 windows and 73 elevators, and there are 1,860 steps from street level to the 103rd floor. It has a total floor area of 2,768,591 sq ft (257,211 m2); the base of the Empire State Building is about 2 acres (8,094 m2). The building houses 1,000 businesses, and has its own zip code, 10118. As of 2007, approximately 21,000 employees work in the building each day, making the Empire State Building the second-largest single office complex in America, after the Pentagon. The building was completed in one year and 45 days. Its original 64 elevators are located in a central core; today, the Empire State Building has 73 elevators in all, including service elevators. It takes less than one minute by elevator to get to the 86th floor, where an observation deck is located. The building has 70 mi (113 km) of pipe, 2,500,000 ft (760,000 m) of electrical wire, and about 9,000 faucets.[citation needed] It is heated by low-pressure steam; despite its height, the building only requires between 2 and 3 psi (14 and 21 kPa) of steam pressure for heating. It weighs approximately 370,000 short tons (340,000 t). The exterior of the building was built using Indiana limestone panels.

Setbacks to taper Structure with height

The Empire State Building cost $40,948,900 to build.  A series of setbacks causes the building to taper with height. Unlike most of today's skyscrapers, the Empire State Building features an art deco design, typical of pre-World War II architecture in New York. The modernistic stainless steel canopies of the entrances on 33rd and 34th Streets lead to two story-high corridors around the elevator core, crossed by stainless steel and glass-enclosed bridges at the second-floor level. The elevator core contains 67 elevators.

The lobby is three stories high and features an aluminum relief of the skyscraper without the antenna, which was not added to the spire until 1952. The north corridor contains eight illuminated panels, created by Roy Sparkia and Rene Nemorov in 1963, depicting the building as the Eighth Wonder of the World, alongside the traditional seven.

Long-term forecasting of the life cycle of the structure was implemented at the design phase to ensure that the building's future intended uses were not restricted by the requirements of previous generations. This is particularly evident in the over-design of the building's electrical system.

Floodlights

Empire State Building with red and green lights for Christmas, as seen from GE Building  Empire State Building with normal white lighting, as seen from New Jersey In 1964, floodlights were added to illuminate the top of the building at night, in colors chosen to match seasonal and other events, such as St. Patrick's Day, Christmas, Independence Day or Bastille Day. After the eightieth birthday and subsequen death of Frank Sinatra, for example, the building was bathed in blue light to represent the singer's nickname "Ol' Blue Eyes". After the death of actress Fay Wray (King Kong) in late 2004, the building stood in complete darkness for 15 minutes.

The floodlights bathed the building in red, white, and blue for several months after the destruction of the World Trade Center, then reverted to the standard schedule. Traditionally, in addition to the standard schedule, the building will be lit in the colors of New York's sports teams on the nights they have home games (orange, blue and white for the New York Knicks, red, white and blue for the New York Rangers, and so on). The first weekend in June finds the building bathed in green light for the Belmont Stakes held in nearby Belmont Park. The building is illuminated in tennis-ball yellow during the US Open tennis tournament in late August and early September. It was twice lit in scarlet to support nearby Rutgers University: once for a football game against the University of Louisville on November 9, 2006 , and again on April 3, 2007 when the women's basketball team played in the national championship game.  In 1995, the building was lit up in blue, red, green and yellow for the release of Microsoft's Windows 95 operating system, which was launched with a $300 million campaign. The building has also been known to be illuminated in purple and white in honor of graduating students from New York University.

Every year in September, the building is lit in black, red, and yellow, with the top lights off (for black) to celebrate the German-American Steuben Parade on Fifth Avenue.

The building was lit green for three days in honor of the Islamic holiday of Eid ul-Fitr in October 2007. The lighting, the first for a Muslim holiday, is intended to be an annual event and was repeated in 2008 and 2009. In December 2007, the building was lit yellow to signify the home video release of The Simpsons Movie.

From April 2527, 2008 the building was lit in lavender, pink, and white in celebration of international pop diva Mariah Carey's accomplishments in the world of music and the release of her eleventh studio album E=MC2.[citation needed]

In late October 2008, the building was lit green in honor of the fifth anniversary of the acclaimed Broadway Musical Wicked by Kerry Ellis and Stephen Schwartz.

Starting in 2008, the building along with New York City and many other cities around the world, participated in Earth Hour. The skyscraper's floodlights were turned off for exactly an hour to conserve energy.

In September 2009, the building was lit for one night in orange colors, in celebration of the exploration of Manhattan Island by Henry Hudson 400 years earlier. The Dutch prince Willem-Alexander van Oranje and princess Maxima were present and turned on the lights from the lobby.

In 2009, the building was lit for one night in red and yellow, the colors of the Communist People's Republic of China, to celebrate the 60 years since its founding, amid controversy.

Observation decks

The Empire State Building has one of the most popular outdoor observatories in the world, having been visited by over 110 million people. The 86th-floor observation deck offers impressive 360-degree views of the city. There is a second observation deck on the 102nd floor that is open to the public. It was closed in 1999, but reopened in November 2005. It is completely enclosed and much smaller than the first one; it may be closed on high-traffic days. Tourists may pay to visit the observation deck on the 86th floor and an additional amount for the 102nd floor. The lines to enter the observation decks, according to the building's website, are "as legendary as the building itself:" there are five of them: the sidewalk line, the lobby elevator line, the ticket purchase line, the second elevator line, and the line to get off the elevator and onto the observation deck. For an extra fee tourists can skip to the front of the line.

The skyscraper observation deck plays host to several cinematic, television, and literary classics including, An Affair To Remember, Love Affair and Sleepless in Seattle. In the Latin American literary work Empire of Dreams by Giannina Braschi the observation deck is the site of a pastoral revolution; shepherds take over the City of New York. The deck was also the site of a Martian invasion on an old episode of I Love Lucy.

A panoramic view of New York City from the 86th-floor observation deck of the Empire State Building, spring 2005

The Empire State Building also has a motion simulator attraction, located on the 2nd floor. Opened in 1994 as a complement to the observation deck, the New York Skyride (or NY Skyride) is a simulated aerial tour over the city. The theatrical presentation lasts approximately 25 minutes.

Since its opening, the ride has gone through two incarnations. The original version, which ran from 1994 until around 2002, featured James Doohan, Star Trek's Scotty, as the airplane's pilot, who humorously tried to keep the flight under control during a storm, with the tour taking an unexpected route through the subway, Coney Island, and FAO Schwartz, among other places. After September 11th, however, the ride was closed, and an updated version debuted in mid-2002 with actor Kevin Bacon as the pilot. The new version of the narration attempted to make the attraction more educational, and included some minor post-9/11 patriotic undertones with retrospective footage of the World Trade Center. The new flight also goes haywire, but this segment is much shorter than in the original.

Broadcast stations

New York City is the largest media market in the United States. Since the September 11, 2001 attacks, nearly all of the city's commercial broadcast stations (both television and FM radio) have transmitted from the top of the Empire State Building, although a few FM stations are located at the nearby Cond Nast Building. Most New York City AM stations broadcast from just across the Hudson River in New Jersey.

Communications devices for broadcast stations are located at the top of the Empire State Building. Broadcasting began at Empire on December 22, 1931, when RCA began transmitting experimental television broadcasts from a small antenna erected atop the spire. They leased the 85th floor and built a laboratory there, andn 1934CA was joined by Edwin Howard Armstrong in a cooperative venture to test his FM system from the Empire antenna. When Armstrong and RCA fell out in 1935 and his FM equipment was removed, the 85th floor became the home of RCA's New York television operations, first as experimental station W2XBS channel 1, which eventually became (on July 1, 1941) commercial station WNBT, channel 1 (now WNBC-TV channel 4). NBC's FM station (WEAF-FM, now WQHT) began transmitting from the antenna in 1940. NBC retained exclusive use of the top of the Empire until 1950, when the FCC ordered the exclusive deal broken, based on consumer complaints that a common location was necessary for the (now) seven New York television stations to transmit from so that receiving antennas would not have to be constantly adjusted. Construction on a giant tower began. Other television broadcasters then joined RCA at Empire, on the 83rd, 82nd, and 81st floors, frequently bringing sister FM stations along for the ride. Multiple transmissions of TV and FM began from the new tower in 1951. In 1965, a separate set of FM antennas were constructed ringing the 103rd floor observation area. When the World Trade Center was being constructed, it caused serious problems for the television stations, most of which then moved to the World Trade Center as soon as it was completed. This made it possible to renovate the antenna structure and the transmitter facilities for the benefit of the FM stations remaining there, which were soon joined by other FMs and UHF TVs moving in from elsewhere in the metropolitan area. The destruction of the World Trade Center necessitated a great deal of shuffling of antennas and transmitter rooms in order to accommodate the stations moving back uptown.

As of 2009, the Empire State Building is home to the following stations:

TV: WCBS-TV 2, WNBC-TV 4, WNYW 5, WABC-TV 7, WWOR-TV 9 Secaucus, WPIX-TV 11, WNET 13 Newark, WNYE-TV 25, WPXN-TV 31, WXTV 41 Paterson, WNJU 47 Linden, and WFUT-TV 68 Newark
FM: WXRK 92.3, WPAT-FM 93.1 Paterson, WNYC-FM 93.9, WPLJ 95.5, WXNY 96.3, WQHT-FM 97.1, WSKQ-FM 97.9, WRKS-FM 98.7, WBAI 99.5, WHTZ 100.3 Newark, WCBS-FM 101.1, WRXP 101.9, WWFS 102.7, WKTU 103.5 Lake Success, WAXQ 104.3, WWPR-FM 105.1, WQXR-FM 105.9 Newark, WLTW 106.7, and WBLS 107.5

Empire State Building Run-Up

The Empire State Building Run-Up is a foot race from ground level to the 86th-floor observation deck that has been held annually since 1978. Its participants are referred to both as runners and as climbers, and are often tower running enthusiasts. The race covers a vertical distance of 1,050 feet (320 m) and takes in 1,576 steps. The record time is 9 minutes and 33 seconds, achieved by Australian professional cyclist Paul Crake in 2003, at a climbing rate of 6,593 ft (2,010 m) per hour.

In popular culture
Film

Perhaps the most famous popular culture representation of the building is in the 1933 film King Kong, in which the title character, a giant ape, climbs to the top to escape his captors but falls to his death. In 1983, for the 50th anniversary of the film, an inflatable King Kong was placed on the actual building. In 2005, a remake of King Kong was released, set in 1930s New York City, including a final showdown between Kong and bi-planes atop a greatly detailed Empire State Building. (The 1976 remake of King Kong was set in a contemporary New York City and held its climactic scene on the towers of the World Trade Center.)

The 1939 romantic drama film Love Affair involves a couple who plan to meet atop the Empire State Building, a rendezvous that is averted by an automobile accident. The film was remade in 1957 (as An Affair to Remember) and in 1994 (again as Love Affair). The 1993 film Sleepless in Seattle, a romantic comedy partially inspired by An Affair to Remember, climaxes with a scene at the Empire State observatory.

Andy Warhol's 1964 silent film Empire is one continuous, eight-hour shot of the Empire State Building at night, shot in black-and-white. In 2004, the National Film Registry deemed its cultural significance worthy of preservation in the Library of Congress.

The film Independence Day features the Empire State Building as ground zero for an alien attack; it is devastated by the aliens' primary weapon which incinerates most of New York City.

Many other movies that feature the Empire State Building are listed on the building's own website.

Television 

The Empire State Building featured in the 1966 Doctor Who serial The Chase, in which the TARDIS lands on the roof of the building; The Doctor and his companions leave quite quickly, however, because The Daleks are close behind them. A Dalek is also seen on the roof of the building while it interrogates a human. In 2007, Doctor Who episodes "Daleks in Manhattan" and "Evolution of the Daleks" also featured the building, which the Daleks are constructing to use as a lightning conductor. Russell T Davies said in an article that "in his mind", the Daleks remembered the building from their last visit.

The Discovery Channel show MythBusters tested the urban myth which claims that if one drops a penny off the top of the Empire State Building, it could kill someone or put a crater in the pavement. The outcome was that, by the time the penny hits the ground, it is going roughly 65 mph (105 km/h) (terminal velocity for an object of its mass and shape), which is not fast enough to inflict lethal injury or put a crater into the pavement. The urban legend is a joke in the 2003 musical Avenue Q, where a character waiting atop the building for a rendezvous tosses a penny over the sidenly to hit her rival.

Literature

H.G. Wells' 1933 science fiction book The Shape of Things to Come, written in the form of a history book published in the far future, includes the following passage: "Up to quite recently Lower New York has been the most old-fashioned city in the world, unique in its gloomy antiquity. The last of the ancient skyscrapers, the Empire State Building, is even now under demolition in C.E. 2106!".

In the science fiction novel The Rebel of Rhada by Robert Cham Gilman (Alfred Coppel), taking place at a decayed galactic empire of the far future, New York is an ancient city which was destroyed and rebuilt countless times. Its highest and most ancient building, covered with piled-up ruins up to half its height, is known simply as "The Empire Tower", but is obviously the Empire State Building.

David Macaulay's 1980 illustrated book Unbuilding depicts the Empire State Building being purchased by a Middle Eastern billionaire and disassembled piece by piece, to be transported to his home country and rebuilt there.

The Empire State Building is featured prominently as both a setting and integral plot device throughout much of Michael Chabon's 2000 Pulitzer Prize-winning novel, The Amazing Adventures of Kavalier & Clay.

In the Percy Jackson book series, Mount Olympus is located over the Empire State Building, and there is a special elevator in the building to the "600th floor," which is supposed to be Olympus.

Tenants
Notable tenants of the building include:
Alitalia, Suite 3700
Croatian National Tourist Board, Suite 4003
Filipino Reporter, Suite 601
Human Rights Watch, 34th Floor
Polish Cultural Institute in New York, Suite 4621           
Senegal Tourist Office, Suite 3118
TAROM, Suite 1410
The King's College, Suite 1500

Former tenants include:
China National Tourist Office (now located at 370 Lexington Avenue)
National Film Board of Canada (now located at 1123 Broadway)
Nathaniel Branden Institute

Gallery
A view upward of the Empire State Building from Broadway
The top of the Empire State Building

Looking up
Looking Down
Looking towards Times Square
Art deco elevators in the lobby
Panoramic view of Midtown Manhattan from observation deck
The Empire State Building lights up in yellow and red during the 60th anniversary of the PRC

GEOTECHNICAL CONDITIONS of UNITED KINGDOM

Natural deposits formed prior to the Pleistocene glaciation are generally referred to as rocks. The strength of these formations can vary such that some of them are classified as soils. These include many of the deposits in the south east of the United Kingdom, such as the London clay and the Gault clay. Most of the UK has been affected by glaciation which has resulted in extensive drift deposits of till (boulder clay), laminated clays and other glacial materials as far south as London. Periglacial and lacustrine deposits are also found in plains and valleys together with estuarine and coastal muds and silts. Peat and other organic soils are found throughout the upland region.

Drift deposits in the upland region are predominantly firm and stiff to hard gravelly sandy clay containing boulders, lenses of sand and gravel. The more recent deposits comprise softer organic and alluvial clays and loose sands.

Swedish Deep Soil Stabilization Research Centre

The Swedish Deep Stabilization Research Centre (SD, www.swedgeo.se/Sd) was founded in 1995 with the aim to initiate and implement comprehensive R&D activities related to dry mixing methods and their practical applications. The objectives and activities were formulated as an industry-wide effort, including government and municipal authorities, material suppliers, contractors, consultants, the Swedish Geotechnical Institute (SGI) and universities. During the progress of the project, the scope was adapted to also include mass stabilization. The main objectives of SD were to:

• establish functional requirements for deep mixing regarding safety and maintenance,

• provide a platform for increased application areas of the method,

• create export opportunities for the industry, by introduction of system concepts for reinforced ground,

• introduce innovative application method aiming at increased competitiveness, overall economy and potential cost savings,

• reduce construction time and avoiding restrictions during the construction phase,

• assure a high competence level by contacts between project owners, contractors, material suppliers, consultants and researchers.

 

The activities of SD ended in 2001 and resulted in a large number of publications. SD produced 12 reports, several of them in English. These will be presented in more detail below.

European Federation of Foundation Contractors

The European Federation of Foundation Contractors (EFFC, www.effc.org) represents about 450 foundation contractors in 17 European countries. Member companies are specialist contractors in the construction industry who undertake the construction of all types of foundations and other geotechnical processes (i.e. piling, diaphragm walling, grouting, ground anchors, ground improvement, dewatering, etc).


EFFC's objectives are to promote the common interests of members of the federation; to improve standards of workmanship; and to maintain high standards of technical competence, safety and innovation throughout the European foundation sector. EFFC's main activities are performed within Working Groups. The Technical Working Group prepares EU technical codes for specialist geotechnical and foundation in cooperation with the CEN Technical Committee TC288.

Reinforcement for Bored Piles

Piles subject to tension or lateral forces and eccentric loading, require suitable reinforcement designed to accommodate these forces. Nominal reinforcement for piles in compression only would be four 12 mm bars for a 400 mm pile to five 16 mm bars for a 550 mm pile. A special cage of 5 mm steel, or hoops of flat steel, are employed as lateral ties. The assembled cage should be sufficiently strong to sustain lifting and lowering into the pile bore without permanent distortion or displacement of bars. Bars should not be assembled too densely that concrete aggregate cannot pass freely between them.

Piles loaded in compression need reinforcement of the shaft to a depth of about 2 m greater than the depth of temporary casing. This is to prevent the tendency of concrete lifting, when pulling the casing.

In longer piles overlapping the reinforcements are very frequent. However, in this case aggregates can assemble at the joints and prevent concrete from flowing towards the borehole walls and result in a defective pile shaft. Over designing of steel reinforcement in a bored pile can lead to practical difficulties in constructing the pile shaft. Where large steel cross-sections are unavoidable, consideration can be given to staggering the joints, although this can be difficult to arrange in prefabricated cages. If bar connectors are used, staggering is not a major problem as the lengths involved are shorter. However, these are designed for use either in tension or alternatively in compression, and it is not generally possible to predetermine the orientation of the cage in the pile bore. Mild steel bars can be butt-joined by welding. Provided high-quality welds are used, this can be an effective solution.

Steel concentration can be adjusted depending on the stress pattern. Similarly a reduced density can b used in the plane of the neutral axis.

High Strength Steel Pipe: Higher Operating Pressure Gas Line

To achieve higher throughput, the pipe line in service have to withstand higher operating pressure. For this purpose high strength steel pipelines are used. For example, actual pipeline operating pressure varies depending on many factors, including the diameter, wall thickness, and grade of pipe, but for the most part it is typically around 1,000 to 1,500 PSI. Using higher strength steel, such as going from X60 to X80, and keeping everything else the same results in a proportional increase in maximum allowable pressure, or in this case, 33 percent higher pressure. In fact, some of the newer high-strength steel pipelines operate around 2,000 PSI.

The high-strength steel also may allow for a reduction in wall thickness, which reduces costs associated with hauling and handling of material, as well as time spent welding the pipe. In case of welding, the arc energy can interact with the ambient air. A partially ionizing the arc into hydrogen is occurred which can be absorbed by the weld metal. This phenomenon is called hydrogen-assisted cracking (HAC). This situation is exacerbated when the welding of these high-strength steels occurs in locations with relatively high humidity, such as Mississippi. This challenge is overcome by low-hydrogen electrodes.

Now-a-days high-strength steel pipe grades like X80 are widely used for long-distance transmission pipelines, but present a challenge for welding. In the past field girth welds on X70 and lower-strength grades were completed almost exclusively with cellulosic electrodes because of their low cost. However, with high-strength X80, cellulosic electrodes typically are used only for root and hot passes and are not used for fill passes, due to the increased risk of HAC.

Application of Jute Geotextile to Black Cotton Soil: A Railway Track Subgrade Improvement Technique

The sub-grade soil is an integral part of Well-built and maintained highways/rail way tracks.It provides the support to the pavement. The sub-grade soil and its properties are important in the design of pavement structure. In India Mainly in Maharashtra, M.P. and Andhra Pradesh Most State I highways have suffered severe problem associated with highly compressible clayey soil, particularly black cotton soil.

The present study indicates that the settlement and shear strength behaviour of black cotton soil is changed appreciably if reinforced with layers of woven/non-woven jute geotextile (JGT), non-woven geotextile and coarse sand drain placed at center in horizontal layer and in the form of vertical drain. 

 

 

A) Nonwoven Geotextile Fabric

B)Non Woven Jute Geotextile

Results show that compression index values decrease by about 8 per cent. 16.5 per cent and 25 per cent with non-woven JGT, woven JGT and non-woven geotextile respectively when compared with virgin black cotton soil. Further, it is seen that by addition of 10 mm dia vertical coarse sand drain in the center of 76.2 mm dia consolidation test, compression index values decrease by about 35.6 per cent, 36.5 per cent and 37.65 per cent with non-woven JGT, woven JGT and non-woven geotextile respectively in comparison with virgin black cotton soil.

 

 It is also observed that shear strength increases by about 13 per cent, 9 per cent, and 1.5 per cent with non-woven geotextile, woven JGT and vertical coarse sand drain respectively when compared with virgin black cotton soil.

Summary:

SI No.	Reinforcing Method	Reinforcement Type	Compression Index(%)	Shear Strength(%)
1	Reinforced with reinforcement and coarse sand drain placed at center in horizontal layer and in the form of vertical drain.	Non-woven JGT	8
		Woven JGT	16.5
		Non-woven Geotextile	25
2	Addition of 10 mm dia vertical coarse sand drain in the center of 76.2 mm dia with reinforcement	Non-woven JGT	35.6	13
		Woven JGT	36.5	9
		Non-woven Geotextile	37.65	1.5

Metal Forms Integrating Dowel Brackets for Casting Deeper Concrete Aporn

Metal forms can be engineered to incorporate special features such as dowel brackets and extensions to pour deeper edges  have simplified the job of paving like 18” thickness apron.

The paving process began by aligning the forms on a four-inch asphalt base, which was laid over a limestone sub-base. Once the forms were aligned, metal stakes were driven with a jackhammer to hold them in position. The stakes were locked to the forms with two opposing wedges in a pocket, which made removal easy once a section was paved.


Another innovation is a separate dowel bracket that holds 1-1/2” diameter smooth metal dowels in alignment perpendicular to the form sections. To avoid wet-set of the dowels a special technique is applied.

 

Metal Forms Engineered With Dowel Brackets

The drawback of wet-set is if dowels aren’t perfectly straight, they have trouble getting the forms off. With the brackets, the dowels were placed on alternate lanes, and the concrete was poured. Two concrete pumps supplied a Gomaco C-450 cylinder finisher with a 650 flex mix that equates to an eight-sack mix.. Although the  Gomaco machine did most of the finishing Additional hand finishing is required around the structure collars. Once the concrete was cured, the forms were removed while leaving the dowels in place. Then, 2” steel tubing was placed on top of the concrete for the Gomaco machine while the remaining lanes were poured. This way, no dowels had to be wet-set, the forms were easy to remove, and the dowels were held in place by the concrete placed first while the second set of lanes was paved.

Practicle example is paving an 18” thick concrete apron that measures approximately 300 ft. x 600 ft. near the Southwest terminal of the Oakland airport. The apron, part of an expansion designed to handle UPS aircraft, consists of seven 40-ft. bays 650 ft. long, totaling approximately 10,000 yards of concrete.

Paving Contractor	M.F. Maher Construction, headquartered in Vallejo, California
Thickness	18” but it is specified to be 21” thick around the perimeter to provide added strength.
Forms designer	White Cap Construction Supply, worked jointly with M.F. Maher.
Forms specifications	Metal Forms developed special forms that accommodate the 18” depth of the pavement but also include a 4-1/2” height extension to handle the 22-1/2” perimeter depth.  Brian Wear, of M.F. Maher, says, “The area has a 10-foot transition from 1” to 22-1/2” around the edge. I didn’t want to buy separate 22-1/2” forms, so they engineered an extension that fits on top.

Amsterdam Airport Schiphol: Polymer Modified Asphalt Surface Runway

To provide additional capacity impacting less to environment in 1999 a new runway (18R-36L) at Amsterdam Airport Schipholwas constructed. The design work for this purpose started in November 1995.

The works included a 3,800 m runway, a 1,050 m long parallel taxiway with four exit taxiways and a 1,950 m connecting taxiway; a four-position de-icing platform, a rescue and fire fighting station, complete airfield lighting system including runway and taxiway stations, approach lighting system with displaced landing threshold and instrument landing systems (ILS) Cat3B for the northern (18) runway approach.

Special attention had to be paid to the locally low bearing capacity of the soil for the runway and taxiway design. With associated soil-mechanic specialists, a new method of pre-loading the primary runway and taxiways areas was developed, which resulted in a significantly shorter duration of pre-loading.

 

This runway is the first runway in the Netherlands with a width of 60 m. The runway and taxiway pavements are designed for code F Aircraft. Polymer modified asphalt (PMA) was used for the asphalt surface layers. The runway opened in February 2003. These construction involved 500,000m³ of soil, 650,000m³ of sand (used to compact the marshy soil and for the first layer of the runway), 750,000t of foundation material, 270,000t of asphalt, 130km of drainage, 34km of cabling cylinders, 170km of cables for lighting and 500 concrete wells to connect cabling and equipment.
Additionally the construction incorporated 1,700 fittings for runway lighting, 20,000 litres of paint for approximately 67km of runway lines and 906m² of markings, 30km of sewage pipes for drainage, 3km fencing and lastly 500,000 transport movements.

Airport Pavement Design

Airport pavement is designed to withstand the stresses imparted to the pavement by aircraft. Depending on the use and local ground conditions, materials are chosen to construct the runway. For a major airport, where the ground conditions permit, the most satisfactory type of pavement for long-term minimum maintenance is concrete. Although certain airports have used reinforcement in concrete pavements, this is generally found to be unnecessary, with the exception of expansion joints across the runway where a dowel assembly, which permits relative movement of the concrete slabs, is placed in the concrete. 

Where it can be anticipated that major settlements of the runway will occur over the years because of unstable ground conditions, it is preferable to install asphaltic concrete surface, as it is easier to patch on a periodic basis. For fields with very low traffic of light planes, it is possible to use a sod surface. Some runways also make use of salt flat runways.

For heavy-duty commercial aircraft, the pavement thickness, no matter what the top surface, varies from 10 in (250 mm) to 4 ft (1 m), including subgrade. These is determined by the subgrade condition (determined by borings). The specifications are established from the relative bearing capacity of the subgrade.

Characteristics and size of the landing gear is very important for pavement design. Manufacturers of the larger planes design landing gear so that the weight of the plane is supported on larger and more numerous tires. Attention is paid to the characteristics of the landing gear itself, so that adverse effects on the pavement are minimized. Sometimes it is possible to reinforce a pavement for higher loading by applying an overlay of asphaltic concrete or portland cement concrete that is bonded to the original slab. 

Post-tensioning concrete has been developed for the runway surface. This permits the use of thinner pavements and should result in longer concrete pavement life. Because of the susceptibility of thinner pavements to frost heave, this process is generally applicable only where there is no appreciable frost action.

Introduction to Floating Concrete Structures

Floating concrete structures are used to construct a large array of structures, such as highways and streets, bridges, large buildings, airport runways, irrigation structures, breakwaters, piers and pavements, silos and farm buildings and homes.

Floating concrete structures are constructed using high strength; quality controlled reinforced concrete which includes pre-stressing or post-tensioning. The designs also take advantage of positive Styrofoam floatation enclosed in concrete.

The design of the floating concrete structure must meet the operating conditions, strength and serviceability requirements, safety requirements, durability and cost-effectiveness. An appropriate design service life is prescribed depending up on the importance of the structure and the return period of natural loads. Its service life is generally expected to be as long as 50 to 100 years with preferably a low maintenance cost.

 As floating structures are inherently base isolated from earthquakes, they are ideal for applications as floating emergency release bases in earthquake level countries. Very large floating structures have been used for storing fuel. Constructed like flat tankers parked side by side, they form an ideal oil storage facility, keeping the explosive, inflammable fluid from populated areas on land.

The materials used for the floating body may be steel, or concrete or steel-concrete composite and the relevant specifications should be followed. Since water tightness of concrete is important to avoid or limit corrosion of the reinforcement, either watertight concrete or offshore concrete should be used.

Advantages of Floating concrete structures:

• Cost effective

• Environmental friendly as they do not damage the marine eco-system

• Easy and fast to construct

• Can be easily removed

• Do not suffer from differential settlement due to reclaimed soil consolidation

• Their positions with respect to the water surface are constant

The tensile strength of concrete is much lower, but by using properly designed steel reinforcing structural members can be made that is as strong in tension as they are in compression.  (ArticlesBase SC #980827)

Flowcrete from Holcim

Flowcrete is a specially modified, highly workable, cohesive readymix concrete designed to meet specific placement and performance requirements. Flowcrete is made from specially selected raw materials and registered admixtures that are exclusively available to Holcim. This gives the concrete enhanced fluidity without promoting segregation normally found in highly fluid mixes. Flowcrete allows greater flexibility in both design and construction.

Flowcrete is designed for strengths from 15 MPa upward for normal placing or pumping. Once placed, Flowcrete is virtually self-compacting and self-levelling, with no segregation and minimal bleeding. The rate of strength gain and attainment of specified 28-day compressive strengths are the same as for normal concrete. Durability is enhan-ced due to improved compaction, and very high quality off-shutter surfaces are obtained. Shrinkage characteristics of Flowcrete are similar to normal concrete.

Flowcrete features and benefits:

• Faster discharge
• Ease of placement
• Less equipment
• Fluidity - flows through narrow spaces and irregular shapes
• High quality off-shutter finishes
• Increased free fall limits and deeper lifts without segregation
• Improved level tolerances of floors and slabs
• High quality finishes can be easily achieved
• Excellent workability
• No segregation - workability is achieved without compromising cohesion
• Greater productivity - flexibility and efficient use of labour 

Placement benefits:

• Lower pumping pressures and longer pipelines allow for less relocation of the pump during pours.
• Flowcrete may be pumped over longer distances, due to its fluidity.
• Flowcrete may be pumped at a faster speed over distance.

Applications:

Flowcrete may be used for all applications:

• Complex shapes
• Areas of congested reinforced elements
• Intricate architectural applications

Function of Steel as Reinforcement in Concrete

Steel is a high-strength material compared to concrete. The useful strength of ordinary reinforcing steel in tension as well in compression, i.e. the yield strength, is of the order of 10 times the compression strength of common structural concrete, or of the order of 100 times its tensile strength. On the other hand, steel is a high-cost material as compared with concrete.

The two materials are best used in combination if the concrete is made to resist the compression stresses. Thus, in reinforced-concrete beams the resists the compression force, longitudinal steel bars are located close to the tension face to resist the tension force, and frequently additional steel are disposed that they resist the inclined tension stresses which are caused by the shear force in the webs of beams.

 

However, reinforcement is also used for resisting compression forces primarily where it is desired to reduce the cross-sectional dimension of compression members, as in the lower floor columns of multistory buildings. Even such necessity is not exist, a minimum amount of reinforcement is placed in all compression members to safeguard them against the effects of small accidental bending moments which might crack and even fail an unreinforced member.

Design Guidelines of Under-Reamed Pile

It is found that under-reamed piles provide an ideal solution to foundation in black cotton soil or other similar types of expansive soils. The design guidelines of under-reamed pile are briefly discussed below:

The diameter of the pile stem (D) varies from 20 to 50 cm. The diameter of the under-ream bulbs (Du) is normally 2.5 times the diameter of the pile stem. It may however, vary form 2 to 3 times (D) under special circumstances. 

In case of double or multi-under-reamed piles, the centre to centre vertical spacing between two bulbs may vary from 1 ¼ to 1 ½ times the under-reamed diameter (D_u). The length of under-reamed piles varies from 3 to 8 meter and their centre to centre spacing should normally be not less than 2 times the under-reamed diameter. 

Significance of Skybridge of Petronas Towers

The Petronas Towers still remain the tallest twin buildings in the world. Its construction started in 1992 And when it was completed in 1998 after a seven year build and it became the tallest buildings in the world on the date of completion. They were built on the site of Kuala Lumpur's race track. Because of the depth of the bedrock, the buildings were built on the world's deepest foundations. The 120-meter foundations were built within 12 months by Bachy Soletanche and required massive amounts of concrete. Its engineering designs on structural framework were contributed by Haitian engineer Domo Obiasse and colleagues Aris Battista and Princess D Battista.

It has two towers with a sky bridge connecting them. Tower 1, the west tower (right in the top-right photograph) was built by a Japanese consortium led by the Hazama Corporation while Tower 2, the east tower (left in the top-right photograph) was built by Samsung C&T and Kukdong Engineering & Construction, both South Korean contractors. The sky bridge contract was completed by Kukdong Engineering & Construction. Tower 2 became the first to reach the world's tallest building at the time.

 

The important feature of it is the highest 2-story bridge in the world-the sky bridge.The 60m long, 10m tall, 653,000kg sky bridge connecting the two towers was prefabricated in South Korea, assembled on site, and jacked up as a single unit to a height of 184m for installation at the 41st floor just above the tower outriggers. This bridge bears on joints that permit lateral displacements of just 25cm - a remarkable precision made possible by the stiffness of concrete to prevent it from breaking during high winds.The same floor is also known as the podium, since visitors desiring to go to higher levels have to change elevators here. The skybridge is open to all visitors, but tickets are limited to about 1000 people per day, and must be obtained on a first-come, first-served basis. Initially, the visit was free but in 2010, the tickets started being sold by Petronas. Visitors can choose to opt for package one which is just a visit to the skybridge or go for package two to go to the skybridge and all the way to level 86. Visitors are only allowed on the 41st floor as the 42nd floor can only be used by the tenants of the building.

The skybridge is designed to evacuate the occupants by crossing the skybridge to the other tower due to emergency like fire. The day after the 9/11 attacks to twin towers of the World Trade Center in New York City a evacuation hoax was conducted which showed that the bridge would not be useful if both towers need to be emptied simultaneously, as the capacity of the staircases was insufficient for such an event. Plans thus call for the lifts to be used if both towers need to be evacuated, and a successful drill following the revised plan was conducted in 2005.

Qingdao Haiwan Bridge is Opened

World's longest over-water bridge opens to traffic in China's Qingdao on the last day of June. It is 41.58km-long which connects the city of Qingdao with Hongdao in Chengyang District and the suburban Huangdao District across the waters of the northern part of Jiaozhou Bay in Shandong Province.

This bridge started construction in 2006 and finished in December 2010. But it takes 14 years to plan since 1993, design was performed by Shandong High Speed Croup. which employed 30,000 workers to build, and used 450,000 tons of steel and 2.3 million cubic meters of concrete, with a total investment of approximately 9 billion yuan.

Jiaozhou Bay Bridge

Qingdao Haiwan Bridge

The bridge will decrease traffic time from Qingdao to Huangdao District by at least 20 minutes and release pressure on the Jiaozhou Bay Expressway. Furthermore, the Qingdao Haiwan Bridge is the starting section of national expressway from Qingdao to Lanzhou and the key part of high way net of Shandong.

Construction of The Giant Qingdao Haiwan Bridge

Construction of The Giant Qingdao Haiwan Bridge

Jiaozhou Bay Bridge is Opened

World's longest over-water bridge opens to traffic in China's Qingdao on the last day of June. It is 41.58km-long which connects the city of Qingdao with Hongdao in Chengyang District and the suburban Huangdao District across the waters of the northern part of Jiaozhou Bay in Shandong Province.

This bridge started construction in 2006 and finished in December 2010. But it takes 14 years to plan since 1993, design was performed by Shandong High Speed Croup. which employed 30,000 workers to build, and used 450,000 tons of steel and 2.3 million cubic meters of concrete, with a total investment of approximately 9 billion yuan.

 

The bridge will decrease traffic time from Qingdao to Huangdao District by at least 20 minutes and release pressure on the Jiaozhou Bay Expressway. Furthermore, the Qingdao Haiwan Bridge is the starting section of national expressway from Qingdao to Lanzhou and the key part of high way net of Shandong.