Chapter 178: The magical mortise and tenon structure! It can’t be shaken down by a magnitude earthquake!
[That's right. Ordinary houses can't even withstand a magnitude 7 or 8 earthquake. If it's Sakura's house, it might collapse at a magnitude 5 or 6.]

[What? We built it like this on purpose, okay?]

[The power of a magnitude 10 earthquake is comparable to the equivalent of 200 tons of TNT explosives. How can it not knock down a mere palace? What a joke! ]

"It can't even be knocked down by a magnitude 10 earthquake? Is that true?"

Chen Lu said seriously: "Of course it is true. Over the past six hundred years, the Forbidden City has experienced more than two hundred earthquakes, big and small, but it has always stood firm."

A British TV station once approached the relevant staff and requested to replicate the Hall of Supreme Harmony to test the earthquake resistance of ancient Chinese buildings.

However, the Hall of Supreme Harmony is too large and too difficult to build using traditional techniques.

The crew had to settle for the next best thing and try to replicate the Shoukang Palace at one-fifth its size.

The test is very simple. It is to simulate an earthquake to see what magnitude earthquake the scaled-down version of Shoukang Palace can withstand.

The experiment began and the magnitude of the earthquake continued to increase.

When it reached the fifth level, Shoukang Palace began to shake visibly, and everyone thought it was about to collapse.

However, as the magnitude of the earthquake increased, it just shook more violently, but there was no collapse at all, not even a tile fell off.

As it was increased to level ten, Shoukang Palace shifted slightly in position, but it still stood firmly in its original place!

The crew was shocked. You know, even now, it is very difficult to build a house that can withstand a magnitude 10 earthquake!

"Moreover, not a single nail was used during the entire construction process of the Forbidden City."

[No nails are used in the whole process? Then how are the bricks and tiles connected? 】

[Nonsense! How can you build a house without nails? ]

[If the Forbidden City didn't use a single nail, I would eat a ton of it right there! ]

There were many architects among the foreigners, and they simply could not believe what Chen Lu said.

You can't build a house without nails, right?

Anna wondered, "Then how do these materials connect?"

Chen Lu smiled and said, "The Forbidden City uses the traditional craftsmanship of ancient Chinese architecture, the mortise and tenon structure!"

The mortise and tenon structure originated in the Hemudu period about 7000 years ago.

Simply put, it is a connection method that combines concave and convex parts on two components.

In a complete mortise and tenon structure, the protruding part is called the tenon, and the recessed part is called the mortise.

It is the main construction method of ancient Chinese buildings.

Its characteristic is that no nails are used, and objects can be reinforced with mortise and tenon joints. It also allows wooden parts to be twisted in all directions, which is more flexible than connections with nails.

Combining several mortise and tenon structures together turns it into another classic structure of ancient Chinese architecture - bracket sets!
The bracket supports the roof above and connects to the pillars below. It plays a very important role in ancient Chinese architecture.

These brackets are the key to the Forbidden City's ability to survive hundreds of earthquakes.

When an earthquake occurs, bracket sets can play a role in starting, supporting, transitioning and ending.

Just like Tai Chi, use softness to overcome hardness and dissipate the impact of the earthquake.

During a magnitude 10 earthquake, the building remained intact, with only a slight shift, all thanks to the capstone.

The topmost layer of the foundation is the capstone.

The upper surface of the capital stone is flat and is mainly used to support the column.

The taproots of the pillars of the Forbidden City are not buried underground, but placed on flat capital stones.

When natural disasters such as earthquakes occur, the base of the column can make reciprocating motion on the surface of the column top stone, ingeniously converting part of the earthquake energy into kinetic energy, reducing internal force damage and producing a multiplier effect.

Moreover, the foundation of the Forbidden City is very deep. Zhu Yuanzhang originally planned to build the imperial city in Fengyang, where he could find the template of the Forbidden City. The foundation of the Fengyang ruins has 18 layers, not to mention the foundation of the Forbidden City, which is even deeper.

During the construction process, a large amount of glutinous rice was added to the Forbidden City.

The main component of glutinous rice is starch, which is extremely sticky.

Tiangong Kaiwu says: "For tombs and water storage pools, add one part ash, two parts river sand and loess, mix well with glutinous rice and sheep peach vine juice, and build light and solid, which will never fall apart. It is called three-in-one soil."

The mortar used to build the Forbidden City was made in this way.

The combination of these multiple factors makes the Forbidden City so impregnable.

[I understand. If those craftsmen dare to cut corners, they will be beheaded by the emperor! ]

[You collapsed a building, but I lost my entire clan! ]

[The craftsmen only need to consider how to build a palace that will last for 600 years, but the emperor has many things to consider.]

[I know about the mortise and tenon structure, it is a very magical building method in China! ]

Chen Lu went on to say: "The magic of the Forbidden City is not only that it can withstand a magnitude 10 earthquake."

When the Forbidden City was being built, craftsmen had to consider four issues.

They are earthquake prevention, fire prevention, flood prevention and heating.

In addition to earthquakes, the Forbidden City is also unique in three other aspects.

You know, the Forbidden City is a wooden building and is very prone to fire.

Starting from Emperor Kangxi, a fire prevention team of more than 200 people was set up in the Forbidden City.

The traditional working method of the fire prevention team can be summarized in twelve words: "ice breaking in winter, watering in summer, weeding in spring, and clearing leaves in autumn."

Winter ice-breaking refers to breaking the ice on the Jinshui River in the Forbidden City to avoid the need for water to put out fires in winter when there is no water available.

In summer, water is stored in 308 large iron, copper and gilded bronze vats in the Forbidden City so that water can be obtained as soon as possible.

Weeding in spring and leaf clearing in autumn means that in spring and autumn, when the grass and trees are lush, the fire-fighting team must promptly clean up combustible materials such as fallen leaves to eliminate fire hazards.

In addition, the Forbidden City is also equipped with a variety of fire-fighting tools such as ladders, fire hooks, fire buckets, and wooden dragon carriages.

Take the water bucket for example, it is very similar to the modern water gun.

In case of fire, carry buckets of water around the palace.

Place the jet bucket in the water bucket, pump water into the jet bucket through the action of the piston, and then press down hard to let the water column spray out.

The maximum range can reach twenty meters!

Looking at the excitement barrels displayed in the hall, the foreigners opened their eyes wide.

[Isn't this the water gun used by the fire department now? ]

[I didn’t expect that China had already made it hundreds of years ago! ]

"As for heating, the Forbidden City uses floor heating."

[Watt? Floor heating? Is this the same thing as the floor heating used by modern people? ]

[That shouldn't be the case, right? How could there be floor heating hundreds of years ago? ]

[Besides, the Forbidden City is a complex of buildings that covers such a huge area, how could the floor heating possibly cover it? ]

[If it is true, can't we apply for a Guinness record? ]

Although China is not the first country in the world to use floor heating, there has never been such a large building complex as the Forbidden City before.

(End of this chapter)