Why are there so few arches in life?

Why do we share a lot of life in life, and there are many forms of life, and there are many forms of ruthless and diverse ups and downs.

Fan Yu came to the broken cave a few times, but he didn't stay for too long. Now that this place has become his own foothold, he has the heart to take a closer look.

If you want to say that it is really broken, it is to dig such a soil hole on the hillside, and Fan Yu is afraid of bumping his head when he stands in it. Although the cave is blind and broken, the mother is still very clean, and everything is neat.

Yu'er, you rest, and cook cakes for your mother. Although the stepmother couldn't see it, after recognizing Fan Yu as her son, she seemed to be greatly satisfied, and the smile on her face never broke along the way.

As soon as he returned to the cave, he prepared something for Fan Yu to eat and drink.

Fan Yu naturally couldn't let his stepmother-in-law Li work alone, so he hurriedly said, "Mother, you don't have to see outside." I don't have any other relatives, but you are like my own mother. If there's any work, I'll do it for you. ”

When the stepmother heard Fan Yu's words, she couldn't help but feel sad again, sad and happy.

He paused with the bamboo cane in his hand and said, "Okay, okay, there is white noodles in the crockpot in the corner, you go and get some." There are also wild vegetables picked by the mother in the basket, and they will be kneaded into the cooking cake later. ”

agreed, Fan Yu took a clay basin and went to the jar to make white noodles. In the past, he often came to bring rice and noodles to his stepmother, but he was familiar with it.

As a result, when I opened it, I saw that the white noodles in this crockpot were less than a bowl. He poured it all out, and it was just a pelvic floor.

Then I opened a jar next to it, and there was not even a grain of rice in it, and the clean rats were disgusted.

Seeing that his stepmother was waiting with a smile on her face, Fan Yu could only smile bitterly at this moment. The Great Song Dynasty is a very wealthy dynasty, why did he come here by himself, not to mention a stick first, and he couldn't even mix a full meal.

I had to send the noodles at the bottom of the pot to my stepmother, Fan Yu said: "Mother, this noodle is less than a bowl, I'm afraid it's not enough to eat." ”

1. Arch bridge.

An arch bridge refers to a bridge in which the arch is used as the main load-bearing component of the structure in the vertical plane. If an arch is formed in the powder layer inside the container that can withstand the pressure of the powder above without transmitting this pressure to the surface below, this face is called an arch bridge. The arch bridge is a curved surface that is raised upwards, and its maximum principal stress acts along the surface of the arch bridge, and the minimum principal stress along the vertical direction of the arch bridge is zero.

The formation and disintegration of arch bridges may occur repeatedly during the powder outflow under the action of gravity, and this kind of arch bridge is called a moving arch bridge.

2. The bow is the oldest kind of catapult in the projectile weapon. It is made up of elastic bowarms and a flexible bowstring, and when the force built up during the stretching of the string is released in an instant, the arrow or projectile that is fastened on the bowstring can be fired at a distant target.

3. Headbands. Headbands, also known as headbands and hairpins, are specially used to fix the hair on the top of the head or head decoration. Some people wear it for decoration, others to avoid sweat from getting into their eyes, and so on. Generally, the material of the headband is made of ABS material.

4. Arches. Arch, which refers to a door with an arc at the top. It also refers to a door where the doorway is intersected by arcs or other symmetrical curves. Arches (also known as rainbow doors) include ordinary inflatable rainbow doors, modeling rainbow doors, special modeling arches and multi-arch conjoined color doors, which have the advantages of convenience, speed and economy.

At present, outdoor advertising is the first choice for opening ceremonies and various expositions, fairs and other activities**.

5. Tunnel. A tunnel is an engineering building buried in the ground and is a form of human use of underground space. Tunnels can be divided into traffic tunnels, hydraulic tunnels, municipal tunnels, mining tunnels, and military tunnels.

The 1970 Tunnel Conference of the International Organization for Economic Co-operation and Development (OECD) combined various factors and defined a tunnel as "a cavern with a cross-sectional area of more than 2 square meters built under any method under the ground and in any manner specified in the shape and size for a certain purpose." ”

Bridges, culverts, dams, European-style buildings, Chinese gardens, public buildings, station bridges, watermelons, shells, cacti, helmets, bows, arches, arched windows, headbands, skulls, chins, glasses, rainbows, etc.

China's most famous ancient bridge - Zhaozhou Bridge, the city gate cave of the city of Zhoucheng and many other ancient and modern bridges and buildings have also been built into an "arch structure".

Characteristics of the arch to withstand pressure: The arch bears pressure and spreads from the vertex to the ends. An arch is a part of a cylinder, and sometimes a spherical part is also counted. The spherical shape of the stone arch bridge is subjected to pressure, spreading from the vertex and closing at another point or two or three points. And many of the bridges are arched.

In addition to arch bridges, there are arches, arch windows, pot lids, tunnels, helmets, etc.

Arched bridges, rainbows, arched doors, crescent moons, long ropes without tautness, and more.

There are so many arched moon doors, shoulder straps for bags, paper clips, bridges, crescent moons, bananas, arched buildings, magnets, rainbows, cup handles, etc., there are so many things that you can observe around you.

Arched moon doors at home, magnets, shoulder straps for bags, paper clips.

Bananas, arched buildings, magnets, rainbows, crescent moons.

Bridges, and the roofs of some houses are also arched.

The handle of the cup is also counted as an ordinary small bench bridge rainbow.

Rainbow arch bridge arched door.

Bridges, houses, windows, home appliances, doors, etc.

Bridge, rainbow, lower waist pose, hehe, nothing else I haven't thought of yet.

Human backs, arched bridges, rainbows, arches, some combs, hairpins, bows, crescent moons, bananas, magnets.

All of them are arched to prevent floods from breaking through the bridge.

In life, we have seen many bridges. Most of these bridges are designed to be arched, why is that? Why not design it as a concave one?

In addition, the bridge is designed as an arch, which will cause inconvenience to traffic. Because it doesn't matter if it's a bridge with a relatively small span, if it's a bridge with a large span, the vault will be very high, which will make the slope relatively large, so that it is very inconvenient for both pedestrians and vehicles to pass. If the bridge is designed in a concave shape, the car will also save fuel, because when the car is driving downward, there will be a force that rushes forward, and has a certain potential energy, which can help it reach the end of the bridge smoothly.

Don't our bridge experts understand this?

In addition, we can understand it this way. Spheres are known to be stronger than any shape. Because the force is applied anywhere in the sphere, the force can be evenly distributed in all directions.

That's why the huge oil storage tanks that are common in our lives are made to be spherical. There are also common light bulbs in our lives, although they are made of fragile glass, but they are more durable when made into a spherical shape.

The representative of the arch bridge in China is the Zhaozhou Bridge located on the Hu River in Zhao County, Hebei Province. Built in the Sui Dynasty and about 1,400 years old, this bridge was designed and built by the famous craftsman Li Chun, and is the earliest and best-preserved ancient stone arch bridge in the world today.

Think about it, what else is similar in our lives? Helmets and hard hats, all we see are arched, also because they can withstand greater impact, which is therefore safer. This structure is characterized by the ability to evenly distribute the forces on the object to all parts of the shell.

Car; Tunnel; Arch bridge; Arch; Gymnasium modeling (Bird's Nest); Helmet; Pot; Shoe.

Arched doors and windows, arched bridges, caves, tunnels, helmets, pot lids, etc.

Bridges, culverts, dams, European-style buildings.

The first arc bridge was arched, and the bow that played cotton was curved, which may not be seen much now. And bread etc....

Arches are generally used in buildings, such as bridges, some window heads, door heads, etc.

Bridge backyard garden gate.

Culverts, bomb shelters.

Subway access.

Tunnels, arches, arch bridges, helmets, pot lids, caves, culverts, bridge tunnels, air-raid shelters, subway passages.