Hong Kong-Zhuhai-Macao Bridge is assembled like "building building blocks".
While leading the design team to fight for the Hong Kong-Zhuhai-Macao Bridge day and night, chief designer Meng Fanchao encountered an environmental problem: the Lingdingyang waters spanned by the Hong Kong-Zhuhai-Macao Bridge happened to pass through the habitat of the national first-class protected animal Chinese white dolphin . How to minimize the interference and impact of the project on the Chinese white dolphin?
After carefully studying the living habits of Chinese white dolphins, they proposed a creative idea: all large components are completed in the factory and then shipped to sea to install, minimizing the number of people, time and equipment for maritime operations, thereby minimizing the interference to the life of Chinese white dolphins.
At the construction site of the Hong Kong-Zhuhai-Macao Bridge, there is no crowded construction scene, but one of the few large-scale equipment is assembled and installed on site. After the piers, bridge decks, steel box girders, , steel pipe piles, etc. are all built in factories in nearby areas. When the weather is calm, they will be transported to the sea and assembled layer by layer. Like building blocks, it is more efficient and more environmentally friendly.
It is understood that the Hong Kong-Zhuhai-Macao Bridge, which is praised by the British " Guardian " as the "Seven Miracles of the New World", has a total steel use of the main bridge in the sea, reaching more than 400,000 tons, and its weight is equivalent to 10 bird's nests or 60 Eiffel Towers. It can be said to be a brilliant mark in the history of my country's steel structure architecture.
The emergence of Bessema steelmaking method in 1858 is a watershed. Before this, , was a more common material choice for iron-based buildings, and the emergence of Bessema steelmaking method made low-cost mass production of steel feasible.
A Bessemay converter located in Sheifeld, England. Source | Wikipedia
Since then, steel has been widely used as a building material in Western European , including the famous Paris Railway Station and France National Library and other large public buildings. At the same time, in 1871, due to the huge fire of Chicago, the destruction of thousands of wooden buildings, and non-combustible building materials such as steel began to be forced to be used. Coupled with the contradiction between economic development and urban land, steel structure buildings began to be widely used in Chicago, and this trend quickly covered the entire United States.
Today, steel structure buildings in developed countries have reached a high level of commercialization. In Japan, one or two hundred steel structure residential buildings are manufactured on the factory assembly line every day; the components and parts used in steel structure residential buildings in the United States are very standardized and serialized.
After the founding of New China, after experiencing multiple stages such as saving steel, restricting use, reasonable use and promotion and application, my country's steel output began to gradually increase, and steel structure buildings have also gradually increased in economically developed areas. Around 2008, thanks to the Olympics, the craze for steel structure buildings arrived, and a large number of steel structure venues, airports, stations and high-rise buildings were built.
Bird's Nest, China's great steel structure architectural map source | pixabay
The National Grand Theater's shell with unique shape is a steel structure shell map source | Architecture & Design
In fact, before the emergence of steel structures, reinforced concrete structure was one of the most common main building materials, with the advantages of sturdy, durability, good fire resistance, and low cost. However, since the main component of concrete is cement, its production process will bring about a large amount of carbon emissions.
With the establishment of the national "dual carbon" goal, steel structures with low energy consumption and low emission attributes have gradually become the backbone of this transformation. According to the relevant data of the Chinese Academy of Engineering , steel structure buildings per square meter can reduce carbon emissions by 15% during production and construction than concrete buildings per square meter. If the recycling and utilization of steel structure residential demolition stage is included, the effect of energy conservation and emission reduction is more considerable.
So, why can steel structures reduce carbon emissions? It can be viewed from the following three stages:
production and construction
steel structure components are relatively slender, while concrete structures are solid components, so the material consumption of steel structures is relatively small; their weight is much lighter than concrete structures, so the energy consumed by steel structure components during transportation is obviously less; in terms of construction, steel structures do not need to use water or formwork, and there are fewer construction personnel and have shorter cycles, which also helps reduce carbon emissions.
Operation and maintenance
Structural system and maintenance system of steel structure are separated from the maintenance system. Under various climatic conditions, maintenance systems with different insulation properties can be used. There is no need to rely on increasing the wall thickness to achieve the purpose of energy conservation and emission reduction in concrete structures.
demolition and recycling
my country is demolishing a large number of concrete and brick-concrete structures buildings, and the recycling rate of concrete and bricks is very low. Steel has the characteristics of recyclable and can effectively reduce carbon emissions.
is based on these green advantages. In recent years, the country has issued a number of major policies to encourage the development of the steel structure industry, including the "Opinions on Vigorously Developing Steel Structure Buildings (Draft for Comments)", "Action Plan for Creating Green Buildings", and "Guiding Opinions on Promoting the Coordinated Development of Intelligent Construction and Building Industrialization". In October 2021, the General Office of the CPC Central Committee and the State Council issued the "Hong Kong Opinions on Promoting the Green Development of Urban and Rural Construction ", which also clearly mentioned vigorously developing prefabricated buildings , focusing on promoting the construction of prefabricated residential buildings in steel structures.
steel structure has been used in the country for a short time. Data shows that currently, steel structure buildings account for more than 40% of the total construction volume in developed countries, steel structure buildings account for only 5%-7% in my country, and steel structure residential buildings account for only about 1%.
Therefore, steel structure applications still need to be improved in many aspects. On the one hand, my country still needs to improve its design and construction capabilities, and it is easy to have insufficient capacity to analyze and solve various technical problems during construction, resulting in a decline in construction quality and efficiency; on the other hand, due to the low threshold, extensive management of domestic steel structure processing enterprises and the lack of attention to various details, there is a gap between the processing details and similar foreign products, such as the supporting maintenance materials and connectors, domestic products are not as complete and durable as foreign products; another particularly important point is that my country has a large talent gap in the field of steel structures. These factors will limit the improvement of steel structure building level capabilities for a long time. How should we overcome them?
Policy support, vigorously promote the development of steel structures
"Several Opinions of the Central Committee of the Communist Party of China and the State Council on Further Strengthening Urban Planning, Construction and Management" proposes that it is necessary to strive to make prefabricated buildings account for 30% of new buildings in about 10 years, and actively and steadily promote steel structures. Data shows that in 2021, the newly started steel structure construction area reached 210 million square meters, accounting for 28.8% of the newly started prefabricated buildings.
unified standards, accelerating the pace towards standardization, scale and marketization
In 2021, the Ministry of Housing and Urban-Rural Development issued the "Guidelines for the Size of Main Components of Steel Structure Residentials", which unified the standards of various components of steel structure residential buildings. It is expected that by comprehensively improving the efficiency of design units and construction companies, the construction cost of prefabricated steel structure can be further reduced, which is conducive to the continuous expansion of the steel structure market share.
In order to help promote the development of the steel structure industry, Poly Capital leads the seed round investment of the steel structure construction industry digital cloud platform "Fruit Core Digital Innovation". Kong Lingzhi, founder and CEO of "Fruit Core Digital Creation", observed that the design and construction process of steel structure buildings is highly non-standard, and the degree of digitalization of the entire industry is low, resulting in a high cost of steel structures, which seriously hinders the promotion and popularization of steel structure buildings. Therefore, the steel structure design software "Fruit Core Engine" was developed to improve the efficiency of steel structure deepening design and contribute its own strength to the development of the steel structure industry.
Under my country's "dual carbon" goal, the development of steel structure buildings has undoubtedly ushered in a period of opportunity. Only by improving and conquering technologies related to steel structure buildings can we build a better low-carbon future.
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compared to concrete buildings during production and construction
