A simple definition of a Megastructure will be like this: "a massive construction or structure, especially a complex of many buildings." Which is true!

But having watched documentary of various Megastructure around the world, I understand that most major Megastructures were basically constructed to solve critical problem facing by people or can threaten the area economy.

Then many questions begin to ring in my mind...
1. Why are there no Megastructure in Nigeria?
2. Does it mean, there are no challenge people are facing that requires Megastructure?
3. Is it that our leaders are so insensitive to the plight of people for them not realize that there are challenges people are facing?
4. Or does our economy wasn't facing any Megastructure deficiencies?

Meanwhile, achieving these Megastructures didn't come cheap nevertheless government will go extra miles to ensure they achieve it.

Examples of Megastructure around the world that shows government sensitivity towards state economy and concerns for her citizens.

1. Hongkong International Airport
The old Hongkong international airport was at the heart of the city and the city is a home for high rise building. As the city continues to be crowded and jam-packed, increasing the airport traffic, this calls for a serious concern about the safety of the city as a single aircraft failure can result to loss of lives and bringing down the high-rise building.

The government calls for a new airport not just ordinary but a world class one but there's no land to spare. So they turn to the sea about 20km away from the city by turning two tiny islands into one after moving more than 500 millions tonnes of earth.

So this airport was built on artificial island and spare the city from danger, and to link the airport to the city, two amazing engineering feats:

a) By constructing the first double-decker suspended bridge
b) By constructing under water highway.

[img]https://en.m.wikipedia.org/wiki/File:A_bird's_eye_view_of_Hong_Kong_International_Airport.JPG[/img]

2. Smart Tunnel Malaysia
Kuala Lumpur is one of the busiest city in Malaysia but every year mother nature threatening to bring it to its knees, drive out with storms, ranging rivers and massive flood and the solution is brief, constructing a single giant road and water tunnel right under the city itself. When rivers jump their banks the tunnel road decks will be able to transform into flood channel to carry the ranger water under the city streets, leaving the country billion economy hanging untouched above.

The tunnel was divided into three Modes
Mode I (ground floor): Was installed with a rail tracks for high speed rail
Mode II (first floor) & Mode III (Second floor): For Road deck or high ways.

Whenever the city traffic begins to build up, Mode II & mode III will be opened to ease the traffic above.

Also, whenever the rivers jump their banks, Mode I will be closed allow the ranging water flow, if the flood keeps increasing Mode II & Mode III will be opened in this way, the road decks are transformed into a flood channel.

3. The Three Gorges Dam - China
The three gorges dam is 2km long and 60stories tall, it takes over 40,000 workers and 17years to build. When it fully comes online, this one dam will produce over 20,000MW of electricity.

Before they can start the construction of the dam, the river has to be diverted and the Chinese government has to relocate millions of people the flooded river will displace.

The river is also a major water line for cargo and passenger ships and in constructing the river means the water way will be obstructed for these ships. So the engineers have to come with enormous solutions.

1. They created a series of lock gates for the cargo ship where the compartment will be flooded with water and lift the ships up stage by stage until to the last compartment at the other side of the river...this method can take up to 4-5hrs which is too slow for the passenger ship.
2. For the passenger ship, a giant lift like an elevator was constructed that will lift both the compartment, water and the ship to the other side of the river within 30mins.

agdb