Text | Editor: Chestnut
Foreword: With the development of the city, people's travel modes are becoming more and more diversified, and the construction of the subway provides a lot of convenience for the people, so there is no need to worry about traffic congestion.
But what makes people wonder is that the subway is dug so deep and so far, why don't we see the dirt in our daily lives being transported out, where does all this dirt go, and what is it used for?
subway
Since its birth, the subway has greatly improved the pace of people's lives.
Since 1863, when the first subway line was built in London, England, this efficient transportation system has gradually spread around the world.
Although the mainland had a difficult time in its early days, it was not until 1969 that the opening of Beijing's first subway marked the beginning of the mainland's subway era.
The subway represents the modern level of a city, but behind the construction of the subway lies the sweat and wisdom of countless hard workers, in the busy city center, how do they quietly complete the tunnel excavation work that is several kilometers long?
The development of the subway has undoubtedly relieved the traffic pressure of the city, and it has developed rapidly in major cities, until today, more than 50 cities in the mainland have opened subways.
However, the operation of this mode of transportation is still in a state of loss, with only five cities making a profit, and facing the problems of large fluctuations in passenger flow and high construction costs.
The subway occupies an important position in the modern city with its unique advantages, compared with the ground transportation, the subway is not affected by traffic congestion, the speed is fast and the passenger capacity is large, providing great convenience for the fast-paced big city life.
Despite this, the subway still faces limitations such as geographical limitations, inability to cover a wide area, and many difficulties in the construction of the subway, such as how to solve the huge earthwork problems generated during the excavation process.
The earthwork treatment problem in the subway construction process has always been a technical problem, and although the traditional cut-and-cover method can solve the treatment problem of part of the earthwork, it is not suitable for the subway construction of the existing city.
Therefore, the drilling method has become the mainstream mode of urban subway construction, and through the use of advanced equipment such as shield machines, the subway tunnel can be smoothly advanced without affecting the daily operation of the city.
It is worth mentioning that the development of China's subway is not all smooth sailing, in the past, due to the lack of advanced shield machine equipment, the mainland in the Qinling Tunnel and other major projects by the German technology monopoly, for which the mainland spared no expense to buy second-hand equipment.
Under the research of researchers day and night, the development of the mainland's shield machine has made a great breakthrough and achieved a qualitative leap.
How are subway tunnels dug?
When we take the subway, we may not think about how the subway tunnel is excavated, in fact, the excavation process of the subway tunnel is very complex and delicate, requiring a variety of technologies and methods.
The open-cut method usually involves workers digging a foundation pit in the ground and starting work in an open-air environment.
In order to ensure the safety and smooth conduct of excavation work, temporary retaining walls and warning signs are often set up around the site to avoid accidental injuries from onlookers.
When digging to a certain depth, construction crews use large excavators and other construction machinery to remove a large amount of soil generated at the excavation site.
By using these machines, workers can effectively direct the flow of soil to specific haul lanes, sending it out of the excavation site before further processing and handling of it.
When digging a tunnel by the underground excavation method, it is necessary for the engineer to dig a shaft in the appropriate place, enter through professional tools, and in the construction process, different underground geological conditions such as hard rock, etc., will be encountered, and the shield machine will be used to solve it.
The advantage of the underground excavation method is to minimize the disturbance to the ground surface and improve the stability of the subway tunnel.
Known as the "king of construction machinery", the shield machine is specially used for tunnel excavation, it has a strong rock drilling ability and the ability to adapt to different geological conditions, which can greatly improve the excavation efficiency.
The circular turntable of the EPB machine is covered with blades that drill through any obstacle in front of the excavation and transport the dirt to the rear for processing.
In the excavation process of the subway tunnel, the synergy of various technologies and methods is very important, whether it is the open cut method, the dark excavation method or the cover excavation method, or the use of the shield machine, all of which provide convenience and efficiency for the construction of the subway tunnel.
At the same time, the rational treatment and utilization of the soil generated during the excavation process also creates a more environmentally friendly and sustainable development environment for us.
Where did the dirt in the subway project go?
In the construction of subways, the reuse of muck also creates employment opportunities and economic benefits, and a large number of workers are needed in the muck treatment plant for transportation, sorting and processing work, from which these workers can obtain a stable income and improve their living standards.
At the same time, the reuse of muck has also led to the development of related industries, such as brick manufacturing and earthmoving, which not only injects vitality into the local economy, but also contributes to the development of the city and society.
In addition, the reuse of muck also helps to protect the environment and promote ecological balance, the traditional treatment method is to directly fill or discard the muck, which will occupy a large amount of land resources, but also easy to cause groundwater pollution.
By reusing the muck, such as for the construction of green belts or soil reclamation and other ecological restoration work, it can not only reduce the waste of land resources, but also promote the growth of vegetation and maintain the ecological balance.
In addition, the treatment of muck in subway construction can also bring social benefits, and by using muck for other engineering projects such as road construction, the need for building materials such as natural sand and gravel can be reduced, thereby reducing the consumption of resources and the input of costs.
The reuse and transformation of muck also helps to improve the quality of the urban environment and enhance the quality of life of citizens, and the use of muck in the construction of open places such as green belts and parks can create a more beautiful and livable urban environment, so that citizens can enjoy the fruits of urban construction more.
In the construction of subways, the rational treatment and reuse of muck is a comprehensive and systematic engineering project.
Through the use of advanced technical means, such as shield machine and grouting, spraying and other methods, it can effectively reduce the generation and discharge of muck, and promote resource recycling, economic development and ecological environmental protection through reuse.
The significance of the subway
During the construction of the subway, in addition to excavating abundant resources, such as soil, the subway also needs to consume a lot of materials and manpower, which brings strong architectural vitality to the city.
The numerous subway construction sites have become an important landscape for the city's development, attracting many jobs and contributing to the city's economic growth.
At the same time, during the construction period, people were actively employed, and their income levels increased, which enhanced their purchasing power and stimulated the vigorous development of other industries in the city.
As an efficient means of transportation, the subway has been continuously increasing in coverage and speed, allowing people to reach all corners of the city in a short time, which not only greatly facilitates personal travel, but also provides a wider range of employment and life options.
A job opportunity may need to span several urban areas, and the absence of efficient subway transportation can lead to a significant increase in commuting costs and increased work stress.
And with the subway, people can get to work more conveniently and enjoy more leisure and family life in a relatively short time.
In addition to providing convenient transportation for residents, the existence of the subway has also greatly improved the environmental quality of the city.
Compared with vehicles such as cars, subways emit fewer pollutants, which improves the city's air quality, which is not only beneficial to the health of residents, but also enhances the city's image and environmental attractiveness, attracting more people to live and travel here.
In addition, the transportation capacity of the subway has also brought many conveniences to the city, and in special circumstances, such as natural disasters or emergency rescue, the subway can quickly transport people and materials, becoming an important way for the city to respond to emergencies.
At the same time, the existence of the subway also improves the land utilization rate of the urban surface, and compared with the ground transportation, the subway runs underground, saving a lot of valuable above-ground space.
Through the development of the subway, the city can achieve "elevation in the air and expansion on the ground", making full use of urban space to meet the growing needs of residents.
However, there are also some problems and challenges in the construction of the subway, which may face various difficulties such as complex strata and high water pressure during the construction process, which require experienced engineers and innovative technical means to deal with them.
At the same time, the operation and maintenance of the subway requires a large amount of capital and manpower investment, and it is also a huge challenge to formulate reasonable fares and operation strategies.
As an important mode of transportation in the city, the subway can not only provide efficient and convenient travel services, promote the development of urban economy and the progress of human society, but also improve the environmental quality of the city and improve the land utilization rate.
The author thinks
As one of the means of transportation for people to travel, it has made a lot of contributions to the development of society.
Although facing some problems and challenges, with the continuous progress of science and technology and the improvement of social needs, it is believed that the subway will continue to play its unique role and make greater contributions to the prosperity of the city and people's better life.