The Forbidden City or Imperial Palace was the palace where the king of China lived during the Ming and Qing dynasties. This is the most important ancient work in the history of China in particular and the world in general. The entire palace is wide 720,000 square meters and has nearly 10 thousand rooms. Built in 1406 and completed in 1420, up to now, after 600 years of change, the Forbidden City is still massive, majestic and retains its excellent status quo.
Cung Cung stands tall before the times and changes of the times
It is estimated that in the past 600 years, this palace has experienced more than 200 earthquakes, including the 1976 Tangshan earthquake of magnitude 9.5, considered the strongest in the 20th century, equivalent to destructive power. of 2 billion tons of TNT. Besides, it also had to go through many natural disasters, big and small, and wars. But all could not overthrow the Forbidden City. So what made the Chinese from ancient times to build such a solid construction?
The Forbidden City is known as the largest and most complete complex of ancient wooden structures in the world
Most people assume that solidity must be built from a very strong foundation in the ground. But the answer is not really. The citadel that kept the palace “immortal”, almost indestructible, was located above, on the roof.
According to researchers and architects, the Chinese 600 years ago used a very clever type of structure called dou con. This is a type of structure that is made up of a set of wooden blocks (fights) and short arms (gangs) that are cut so that when overlapped they will intertwine to form a unified block. Its principle is the overlapping technique.
The extremely solid and flexible structure of the kumquat
In particular, it does not need screws or glue to connect, but only needs to be installed in the right mold to fit smoothly, forming a solid system, much more flexible than any screw.
The roof has a reinforced structure
The frame structure to support the roof with corrugated iron (right) is much stronger than that of ordinary houses (left).
It is this ingenious structure that holds the roof and frame firmly in place. In the documentary Secrets of China’s Forbidden City of the BBC, experts conducted an experiment that gave amazing results on the strength of the wooden roof. They built a 1:5 scale model of the house and used an earthquake shaker to measure the durability of the building using corrugated iron.
When trying to turn on the device at 9.0 magnitude, the model appears to be unharmed. Raised to 9.5 magnitude, equivalent to the strongest earthquake of the 20th century, the model shook violently but still stood. And in the end, its endurance reached 10.1 degrees richter. In the history of mankind, no earthquake of this magnitude has ever been recorded.
The results show that the model can withstand an earthquake of up to 10.1 magnitude and still does not collapse
However, the Forbidden City is not the first time that the dou-con architecture is used. It has appeared since the Spring and Autumn period in Chinese history, up to 2,500 years ago. In other East Asian countries, this invention is also popular. To this day, the interesting and masterful inventions of the ancients are still applied to modern architecture.
The roof has also help to expand the porch area and increase the aesthetic value
In addition to the roof structure, many small details inside the Forbidden City also contribute to the immortality of the work. For example, the pillars in the palace are not buried deep underground but are erected directly on the stone pillars. In the event of an earthquake, the pillars will not break due to direct contact with the ground, but only move. Or as below the floor, there are also at least 3 layers of bricks, creating an invincible solidity for the building.