Why did the Lu Ban lock, designed 7,000 years ago, help the Forbidden City resist earthquakes?

A, because the Forbidden City is built on a soft foundation

The Forbidden City's grass-roots level is in the stake reinforced fill layer → raft bearing platform → glutinous rice juice layer → gray layer → loess layer → crushed bricks layer → pebbles layer, so that the layers stacked on top of each other, and the stake fill layer and the raft-type bearing platform is also equivalent to the Forbidden City is under the bottom of the sponge, glutinous rice juice is more like the bottom of the sponge coated with a layer of extremely viscous lubricant. Like the bottom of the sponge coated with a layer of highly viscous lubricant, so that the base of the Forbidden City is relatively soft, but also can cushion a sector of the pressure.

We have learned in the historical data, the construction of the Forbidden City in the preparation of materials spent ten years, and at that time the ancient superstitions have been y rooted, they believe that the Forbidden City is a symbol of the highest power, so in the process of construction can not appear a little accident, which also allows the designers to the Forbidden City, the foundation of the construction of the very complex.

Two, the layout of the Forbidden City is more reasonable, and the toughness of the wood itself is better

We see the Forbidden City in fact, inside the house inside the beams are relatively low, the design is also very reasonable, so in the earthquake slide when there will be a damping effect, but also be able to improve the stability of the Forbidden City are mostly wood! In fact, in terms of earthquake prevention, mainly rely on the wooden structure, because wood has a certain degree of flexibility, the role of external forces are easy to deform, but wood to a certain extent and can be restored.

Three, the wall is wide and thick, can inhibit the seismic action caused by the wooden frame too large lateral deformation

The Forbidden City wall bottom thickness of 10 meters, top thickness of 6 meters to 7 meters, the wall is 9.9 meters high, so when the earthquake hit, and thus also in a certain limit to protect the safety of the building, in 1679, Hebei Yanshan In 1679, Hebei Yanshan earthquake, the earthquake is more widespread and still loss of one of the more serious earthquake, the area of destruction is also very large, but the Forbidden City in the earthquake has not been damaged, but also the world's architectural history of a great miracle.