How did ancient times without nails ensure that wooden buildings did not collapse?

The ancient ironmaking technology was underdeveloped, and small hard nails could not be smelted. So ancient nails could not bear the gravity of those big pillars. If used, the house will soon collapse and cause damage. Therefore, nails only work in small places, such as the joint between roof tiles and beams, which is difficult to be noticed and easily leads to the illusion that ancient craftsmen don't use nails. Another reason why the ancients didn't use nails was that there were no tools such as lathes and steam engines in ancient times. Nails can only be inverted, but because the mold can not be standardized, it was not practical at that time. Apart from mud, the most commonly used building is wood, which is cut into various shapes and connected with each other, called tenon and mortise. Since the Warring States Period, tenons and mortises have been widely used. When building houses, tenons and mortises have obvious effects and become the first choice. Every piece of wood is fastened seamlessly, and no nails are needed at all.

The tenon-mortise structure refers to the ingenious combination of more and less wood, high and low wood, long and short wood, which can make use of the torsion between wood to achieve a perfect combination, without any nails at all, and with great pressure. The tenon of tenon-mortise structure is convex, and the base is concave. There is a strong relationship between tenons and mortises, which is the greatest essence of China traditional architectural culture and the pride of China people. The principle of lever balance was adopted in the construction of Zhenwu Pavilion. The Zhenwu Pavilion built by this principle is like a balance, and the attic on the second floor is equivalent to being placed on both sides of the balance, which is already very balanced. However, the four hanging gold pillars are naturally not load-bearing, but preventive balance. These four pillars can play a balance role inside and outside the attic, which is why Zhenwu Pavilion has stood for hundreds of years.

Mortise and tenon is a very ingenious invention, which makes the traditional wooden structure in China a special flexible structure that surpasses the bent, frame or rigid frame of contemporary buildings. It can not only bear a large load, but also allow some deformation, which can offset some seismic energy and reduce the seismic response of the structure under earthquake load. The tenon-mortise structure is the combination of tenon and tenon, and it is a clever combination of more and less, height and low, length and short between wood blocks, which can effectively limit the distortion of wood blocks in all directions. The most basic tenon-mortise structure consists of two components, in which the tenon of one component is inserted into the tenon groove of the other component to connect and fix the two components.