According to the data, the Shanghai Tower began construction on November 29, 2008 and was completed on March 12, 2016. The number of floors is 127 above ground and 5 floors underground, with a total height of 632 meters. Until December 2021, the new merdeka 118, the world's second tallest skyscraper, was on display as the world's second tallest building.
Bearing
To answer the first question, the Shanghai Tower is located in the Pudong area of Shanghai, which is itself in a base area, soft and contains a lot of clay. In order to support the weight of the entire building, the engineers built a total of 980 foundation piles, and the depth reached 282 feet, that is, about 86 meters.
Not only that, but under the condition that the foundation pile can carry a certain amount of gravity, the engineers also poured 2.15 million cubic feet of concrete for reinforcement, forming a foundation slab with a thickness of 6 meters. In such cases, the pressure of each load-bearing column is at least more than 1000 tons.
In this regard, some people may wonder whether after the number reaches a certain level, or the thickness of the load-bearing columns reaches a certain level, the load-bearing task of the entire building can be completed. In fact, the answer is not so, in order to complete the load-bearing requirements of the entire building, Shanghai Tower is still facing a very important problem.
Engineers found during construction that when the foundation floor of the Shanghai Tower was poured, they found that the deep foundation pit of the main building was a rare single building foundation pit with ultra-deep, large and beamless support in the world. With an area of 11,200 square meters, it is unheard of to complete the supply and pouring of concrete.
In order to solve this difficulty, engineers built 955 main building pile foundations in the base to carry the load of the 121 former main building of shanghai tower. It is under such construction techniques that the bearing pressure of the Shanghai Tower is perfectly solved.
Of course, in the relevant introduction here, many people may not understand the difference between load-bearing columns and foundation piles.
The column is mainly subjected to axial pressure, which is used to support the superstructure and transmit the load to the vertical straight rod of the foundation, while the pile is a structure that relies on friction resistance and end resistance to bear the load on the top of the pile, which is specifically responsible for transmitting the load on the pile to the foundation soil.
Thickness and quantity
So is the number and thickness of the load-bearing columns greater and the thicker the better? The answer is not. The first is in terms of quantity, in fact, the more the better, any building, in the process of construction and construction, will not deliberately pursue the number of load-bearing columns. After all, no matter how many there are, if there is not enough carrying capacity, it will eventually be in vain.
In terms of thickness, in fact, the same is true, if only the pursuit of width, or enough width can support the weight of the entire building, then people only need to build as thick as possible? But the truth tells us that the answer is not.
In modern architecture, when building load-bearing columns, steel cages are generally made in advance. After that, the construction crew will pour enough concrete into the steel cage to allow the concrete to solidify naturally. However, if the load-bearing column is too thick, that is, the cross-sectional area is too large. Then in the pouring process, there will inevitably be uneven temperature of concrete.
In such cases, the solidification rate of concrete will also be different due to the influence of temperature. Many times, the outer surface layer has gradually solidified, but the internal concrete has not yet had any solidification phenomenon, and the final construction of the load-bearing column will be extremely dangerous.
Supertall buildings, in particular, like the Shanghai Tower, inherently require a sufficient number of load-bearing columns to share the pressure. In such a case, even if a certain number of load-bearing columns are reduced and the thickness is raised, it is impossible to improve much. Even if there is incomplete concrete condensation in a certain load-bearing column, the impact on subsequent construction is extremely bad.
So in such a situation, when there are related restrictions on thickness and quantity, how should people build supertall buildings like the Shanghai Tower? In fact, the answer is very simple, that is, to find a way on the material.
material
According to the data of GB50010-2010 "Code for the Design of Concrete Structures", the strength of concrete is generally divided into 14 grades from C15 to C80, and the higher the grade, the stronger the ability to withstand pressure.
Therefore, when building a super high-rise building like the Shanghai Tower, the construction party will generally choose concrete with sufficient strength for construction. In such a situation, people naturally do not have to worry about any problems in the construction.
This is actually quite easy to understand. Just like the tofu blocks we see every day, no matter how hard we try to stack them, they can never be superimposed to too high a height, because the tofu blocks themselves are a very fragile material. However, if it is replaced by a material such as wood or brick, then there is no problem with the corresponding height.
According to the data, when the construction of the Shanghai Tower was carried out, the materials used were almost all above C30. In order to ensure the stability of the construction building, even at different heights, the grade of concrete used is not the same. The main reason for this situation comes from the extremely strong wind pressure faced by the upper structure of supertall buildings. In order to resist this pressure, it is natural that the stronger the better.
Architectural skills
So can the building ensure that it does not fall when the load-bearing columns are sufficient or suitable? The answer is not. Why won't the Shanghai Tower be crushed? In addition to the load-bearing capacity of the load-bearing columns and the concrete base of up to 61,000 cubic meters, a more important reason lies in excellent construction skills.
The Shanghai Tower has always relied on three interconnected systems to maintain an upright state. The first of these systems is vertically supported by 27x27 reinforced concrete core columns. If the comparison is made with ships, then the system can be seen as the keel part of a ship. It is precisely because of its existence that the entire Shanghai Tower will be incomparably strong.
The second system is a ring composed of a reinforced material "super column", the main function of this ring is to surround the reinforced concrete core column, and through the steel bearing support and reinforced concrete core column to link. In this case, these steel columns can support the Shanghai Tower while resisting the pressure from the side.
The last system is in the Shanghai Tower, where a 2-storey ribbon truss is used every 14 floors to protect the entire building. In the eyes of tourists, this ribbon truss that appears every 14 floors is only a definition of each area of the Shanghai Tower. But in fact, it is under the protection of the ribbon truss that the stability of the Shanghai Tower has been further improved.
It can be seen that a super high-rise building wants to ensure that it can stand up, and its degree of difficulty is definitely far beyond the imagination of ordinary people. In the current world, although it is not a handful of countries that can build such a high building, it is absolutely rare.
Hundreds of years ago, China lagged behind the rest of the world in every way, and when the U.S. industrial infrastructure had become the world's largest, China even remained in the feudal dynasty period. But even under such circumstances, China has gradually caught up with the pace of construction in various countries in the world, and has even become the world's first infrastructure country, which is definitely worthy of the pride and pride of all Chinese people.
In the future development, we can still expect that China can still build higher buildings. Whether it is in the development of the materials required for load-bearing columns, the laying of reinforced concrete, or the construction skills, we still have a lot of room for improvement. When these building needs are improved and improved, perhaps the world's tallest building will appear in China in the future.