Skyscrapers are architectural marvels that define a city’s identity and culture, while at the same time serving as engineering marvels that showcase innovative construction techniques and designs.
Since the advent of tall buildings in the 19th century, numerous improvements have been implemented. One such improvement is diagrid structures which efficiently distribute loads while resisting wind pressure forces.
The Empire State Building
As New York City experienced a boom in the late 1920s, builders set their sights on constructing the tallest building possible using cutting-edge technology. Businessman John Jakob Raskob created the Empire State Building to outdistance 40 Wall Street and the Chrysler Building by using an innovative mooring mast originally intended as an airship docking station. To keep pace, architects and engineers added an ingenious mooring mast.
Empire State Building held onto its title of the world’s tallest structure for more than four decades due to its 102 floors and unique Art Deco aesthetic, which embodied modern aspirations and technological progress.
Today, the Empire State Building stands as an iconic representation of New York City and remains relevant in modern society. Recent renovations focused on energy efficiency – making it a model for sustainable retrofitting of historic buildings – while using its iconic silhouette to promote events, raise awareness, and mark holidays.
The Sears Tower
In 1974, Chicago became home to the world’s tallest building – now called Willis Tower– when Sears Tower officially reached 110 stories. Today it remains America’s tallest skyscraper.
Sears Roebuck and Company was then the world’s leading retailer when they approached Skidmore, Owings, and Merrill with the desire of consolidating all their scattered offices into one head office building – but wanted something big while keeping costs at a minimum.
Engineer Fazlur Khan created a system of interlinked tubes to provide physical strength for his building, with their rigid perimeters bracing against each other to form the cellular structure that gives its signature staggered level look.
This groundbreaking structural system saved both the firm and the client considerable sums of money, as well as being an astounding demonstration of Khan’s innovative spirit and willingness to push the boundaries of conventional design methodologies. His approach contributed greatly to skyscraper construction history – and is one reason that the Willis Tower remains such an iconic landmark of our city.
The CN Tower
The CN Tower is a Canadian communications and broadcasting hub connecting millions of people using its innovative facilities. This iconic structure also serves as a must-see tourist attraction due to its breathtaking viewing decks and beautiful panoramas.
On February 6, 1973, construction of the CN Tower officially commenced with massive excavations to lay its foundation.
Workers poured concrete into a slip form mold supported by hydraulic climbing jacks and slowly moved upwards until achieving its distinctive tapered form.
The main section of the CN Tower consists of a hollow hexagonal concrete pillar containing elevators, stairwells, power and plumbing connections and broadcast antenna attachment points. Furthermore, there is also an observation deck equipped with glass floors as well as a rotating restaurant open for tourists to experience its 360-degree revolving experience.
The Tokyo Skytree
The Tokyo Skytree stands as the world’s tallest freestanding structure and serves as a symbol of Japan’s innovative future. Architects behind its construction set out to design something not only attractive for cityscape, but one which would serve as a bridge between tradition and progress.
Beginning with the core column, which consists of a reinforced concrete cylinder extending from ground level up the tower’s tower wall, they used an innovative system similar to Japanese pagodas to help mitigate seismic vibrations and reduce swaying during an earthquake by as much as 50%. To do this, they utilized an anti-vibration design with a central pillar utilizing a system similar to Japanese pagodas’ central pillar which diffuses vibration and allows for less swaying by 50% during an event such as this earthquake.
So they added a steel framework around its core. And to ensure stability during an earthquake, they installed zig-zag joints commonly seen on marine structures like oil rigs.
