World's Tallest Building

BURJ DUBAI

Burj Khalifa has been designed to be the center piece of a large-scale, mixed-use development that would include 30,000 homes, nine hotels such as The Address Downtown Dubai , 3 hectares (7.4 acres) of parkland, at least 19 residential towers, the Dubai Mall, and the 12-hectare (30-acres) man-made Burj Khalifa Lake.

The building has returned the location of Earth's tallest freestanding structure to the Middle East the Great Pyramid Of Giza this achievement for almost four millennia before being surpassed in 1311 by Lincoln Catherdral England.

HEIGHT OF BURJ DUBAI OF ALL BUILDINGS

The final height of the Burj Dubai officially remained a secret during construction with the developer, Emaar, keeping schtum when asked. Various leakages resulted in most of the world speculating on 818 meters as the final height, although as the last bit is a spire being jacked up from the inside, it could make sense that more spire gets added and jacked up further to confound the statements of final height. Unless the jacker-upper gets distracted by an attractive bird flying past and the spire falls out. After an Emar press release headline on 30 December 2008 said that the Burj Dubai was "over 780 meters and climbing ... ", several media sources in January 2009 said that the final height of 780m had been reached, while other sources said the Burj Dubai had topped out at a final height of 818m (and quoted inside information), and further sources said the tower was up to 780m or 818m and still rising. As with many reports in Dubai, trying to verify the accuracy of reported information can have the opposite effect and throw up more and more inconsistency.

Word's Biggest Bridge

THE SAN FRANCISCO-OAKLAND BAY BRIDGE

Location: Interstate 80 between San Francisco and Alameda Counties.

Length:23,000 feet (4.5 miles), total project: structural and roadway including approaches, toll plaza, etc.,8.4 miles.

Structure: Suspension, tunnel, cantilever and truss

West Bay Suspension Bridge:Length 9260 feet (2822 meters)

Vertical clearance: 220 feet

Span Length: 2,310 feet

Tower Height:526 feet (from water level)

East Bay Cantilever Bridge:Length 10,176 feet ,Vertical clearance 191 feet

Span length: 1,400 feet

Deepest Bridge Pier: 242 feet below water level - 396 feet high

Tunnel: Largest bore tunnel in the world: 76' wide, 58' high (546 meters (1700') long)

Opened: November 12, 1936

Cost: $77 million (Including Trans bay Transit Terminal)

Traffic Lanes: Upper level: five lanes westbound

Lower level: five lane eastbound

Avg. Daily Traffic: 270,000 vehicles

CONSTRUCTING THE IMPOSSIBLE

Conceived in the Gold Rush Days, a bridge spanning the San Francisco Bay linking The cities of San Francisco and Oakland always seemed like an engineering and financial impossibility. The water separating the cities was too deep and wide. In fact, in 1921 a trans bay underwater tube crossing was recommended as the best way of crossing the bay. However this idea was soon deemed inappropriate for automobile traffic.

In 1926, the California Legislature created the Toll Bridge Authority, a policy-making body charged with the responsibility for bridging San Francisco and Alameda County.

The challenges facing the Toll Bridge Authority were monumental. California State Highway Engineer Charles C. Purcell was put in charge of organizing the design and construction of the Bay Bridge. Fortunately, between the two shorelines was a mountain of shale rock rising above the Bay: Yerba Buena Island. The island divides the Bay into two sections allowing for two crossings, which would meet at the island. Permission was granted from the Army and Navy, tenants of the island, to use it as an anchorage.

Yet spanning the 1.78 miles between the San Francisco and Yerba Buena Island required ingenuity on a grand scale. The water, 100 feet deep at some points, and the underlying soil conditions required new techniques for placing bridge foundations. The solution: build two suspension bridges.

A total of 17,464 wires, each 0.195 inches in diameter, were spun in each of the two cables supporting each bridge. A shuttle wheel took a loop of wires from one anchorage and carried it over the towers to the other anchorage, hooking it to anchored eye bars. The shuttle then picked up another loop of wire and shuttled it back, hooking this loop on an at the other end. In this manner the cables were spun, forming a cable which is 28.75 inches in diameter. Each cable exerts a pull of 37,million pounds of dead and live load on its anchorage.