Why build a subway? Why do big cities have to build subways?

And not every city can build a subway, which involves the topography and the size of the city.

But for a large city with tens of millions of traffic, the bus system alone is not enough. The volume of public transport is stretched thin in our small cities of several million, let alone in the tens of millions of large cities.

Therefore, the subway system is the only choice for transportation planning in large cities (some places are light rail), and the subway is built underground, does not occupy the land on the ground, so that the planning is also very simple, but the problem encountered is that the subway construction period is long, the amount of engineering is large, and the shortcomings such as large investment funds restrict the possibility of building subways in small cities.

Although the subway has the above shortcomings, its advantages are also obvious: the advantages of speed blocks and large capacity.

The first thing we need to be clear about is that the subway system, like the bus system, is not operated by the state, but it is a real livelihood project. If you lose money, the state will also provide corresponding subsidies to the operating agency to maintain the operation. (This is a reflection of why we should pay taxes).

Although the subway will not bring any direct financial benefits to the operating institutions and the country at present, the construction of the subway is very necessary for the country and the city in the long run.

According to the statistics of the 2011 Beijing Transportation Development Annual Report, traffic congestion costs Beijing 105.6 billion yuan a year, which is equivalent to Beijing's GDP. This is still based on the presence of a subway.

Therefore, whether a city's transportation is developed or not is not only related to people's travel, but also reflected in the city's GDP.

Although the subway cannot directly bring benefits to the country, it is also to facilitate the development of the country.

Today's big cities did not deliberately plan for development when they were developed, so it is inevitable that there will be such and such problems after the development of large cities, and traffic problems are the first to bear the brunt.

Finally, I also hope that small cities can learn from the experience of big cities in the process of development, and do a good job of urban planning. This is good for the people and good for the country.

The subway construction fund consists of two parts, one of which is the financial fund; Second, the subway company bank loan. At present, due to the long construction period of the subway, involving a wide range of specialties, huge investment, high operating costs, but its attributes are municipal infrastructure, public transportation, so the fare is low (some cities subway fares and bus fares are similar, Beijing and Shanghai do not have a reference, two people have their own situation), so simply rely on fare income, loss is inevitable. At present, not only China, but also the world's subways are losing money, except for the Hong Kong subway.

The subway has been an important transportation facility in modern cities for about 100 years. In 1863, the world's first underground began running in the UK. By the early 90s of the 20th century, more than 200 subways had been built in 88 cities in 39 countries in the world, and more than 50 million people took them every day.

What was the reason for the construction of the underground railway? Practice has shown that the subway has various characteristics such as the speed of vehicles running quite fast, the number of trains is very large, the passenger volume is large, convenient and comfortable. In wartime, the underground railroad was also a fairly good anti-aircraft shelter.

Let's take the Shanghai subway as an example to go to the superiority of the subway. Aokai.com.

1.It's very fast. Shanghai Metro Line 1 is about 1 kilometer long and has a total of 13 stations. The speed of the subway is about twice as fast as that of the bus, and it takes only 20 minutes to take the subway, which would have taken 1 hour. Aokai.com.

2.There are a lot of trains. The interval is approximately 2 minutes. Aokai.com.

3.The passenger traffic is quite large, and it is convenient and comfortable. Shanghai metro cars are mainly imported from Germany.

The carriages are about 23 meters long and 3 meters wide and can carry more than 400 passengers, and the compartments are more relaxed than the buses, and at the peak, 5 6 people per square meter stand, but the bus is 12 people. Aokai.com.

In Shanghai's metro stations, which are usually air-conditioned, equipped with closed-circuit television, radio and automatic fire alarm systems, and department stores, it is a very safe place to use as an ideal air defense place in wartime. Aokai.com.

Because the subway has so many advantages, for this reason, many of the world's largest cities have subways.

There are many reasons for the construction of the subway, but the main reason for this is traffic congestion. The number of city dwellers is increasing, and so is the number of cars. Even cities with vast roads are facing traffic paralysis.

In this case, the advent of the metro becomes a more efficient solution.

The subway system operates differently than buses, which generally follow the road and need to follow the traffic rules on the road. Metros, on the other hand, run on an underground rail system, which is faster and more efficient without road congestion. In addition, subways generally have relatively fixed routes and schedules, which also makes it easier for passengers to plan their trips and arrive at their destinations on time.

Therefore, the construction of subways can effectively alleviate the problem of urban traffic congestion and improve the efficiency of urban travel.

At the same time, in order to promote low-carbon travel, many cities have also begun to build subway systems. Compared with traditional buses or taxis, subways are more energy-efficient and environmentally friendly, reducing exhaust and noise emissions. Low-carbon travel can not only reduce environmental pollution, but also bring a healthier lifestyle to urban residents.

In addition, the construction of the subway is also aimed at improving the city's image and attracting investment. With the continuous development of the economy, the image of the city is becoming more and more important for investors. The construction of the subway can not only improve the city's traffic efficiency and ecological environment, but also increase the city's aesthetics and urbanization level.

Therefore, the construction of the subway can not only solve the city's traffic problems, but also improve the city's image and environmental protection. In the future, in the process of economic development and urbanization, the subway will be more important. <>

1. Cut-and-cover backfill method: The simplest and most direct method is cut-and-cover (cut-and-cover backfill). This method is usually to dig a large pit in the street and then construct a tunnel structure underneath it, and the tunnel will have sufficient support to resurface the road surface.

In addition to the road being excavated, other underground structures such as power lines, ** lines, water pipes, etc. need to be reconfigured. The materials used to build such tunnels are generally concrete or steel, but older systems also use brick and iron.

2. Drilling method: Another method is to dig a shaft somewhere on the ground first, and then dig a tunnel at the bottom of the shaft. The most common method is to use a boring machine (submersible shield, shield machine) to install the pre-prepared components on the tunnel wall while excavating.

For places with a high density of buildings, such as Hong Kong Island in Hong Kong, drilling is even the only feasible construction method.

The steps for the construction of the subway are as follows:

Material preparation: construction team, a selected subway line, reinforcement mesh, concrete, boards, cables and mechanical and electrical equipment, etc.

1. First of all, it is necessary to explore the soil reform and disturbance of the subway line that needs to be built, and choose different excavation methods according to the exploration, including open cut and backfill method, shield method, and different methods need to be selected according to different exposed conditions.

2. When digging the soil, the reinforcement mesh is erected at the same time, and the water contained in the soil is discharged to ensure the firmness of the frame and prevent accidents on both sides.

3. Inject concrete into the built steel mesh, and build the bottom plate, side wall, middle plate and roof plate in turn after the concrete is solidified.

4. After the completion of a series of nuclear bench projects, it is necessary to lay tracks, cables, optical cables, communication and other equipment in the subway tunnel.

5. After installing a series of mechanical and electrical equipment, it is also necessary to decorate the station, install mechanical and electrical equipment, system commissioning, acceptance and other related links. After the above links are completed, the subway can be officially operated, but the operation of the subway must be monitored at any time to avoid accidents, and it is also necessary to regularly repair the subway-related equipment to prevent the aging of the equipment.

01 In large cities, education, medical and other resources are relatively concentrated.

First of all, I want to say that if you find that there is no, big cities, educational resources, and medical resources tend to be more concentrated!

Some good high schools and universities are often in big cities;

Some good hospitals, good doctors, also tend to be concentrated in big cities.

Therefore, one of the reasons why many people like to rush to big cities is that the resources of education and medical care in big cities are relatively concentrated.

In this way, compared with small cities, in large cities, they can often enjoy better educational resources and medical resources!

There are many job opportunities in big cities, and wages are relatively high.

Not only educational resources and medical resources, but also in terms of employment opportunities, big cities are often more auspicious!

Generally speaking, there are often more job opportunities in big cities than in small cities!

The average salary in big cities is often much higher than in smaller cities!

For example, for example, the average salary in first-tier cities such as Shanghai and Beijing is generally much higher than that in cities like Hefei and Wuhu!

Therefore, when many people are looking for a job, they often like to go to the big city, and the reason is in this delay!

Not only are there many opportunities, but the income is also relatively high!

Megacities and megacities are eligible to build subways.

In addition to the two points mentioned above, there is another point that I think is also important.

That is: compared with the general small and medium-sized cities, megacities and megacities will be eligible to build subways.

Because there are hard and fast rules: the subway requires a GDP of more than 300 billion yuan, an urban population of more than 3 million, and a local general budget revenue of more than 30 billion.

As the saying goes: as soon as the subway rings, **10,000 taels!

The subway can indeed bring a lot of convenience to everyone's urban travel!

Advantages of the subway. Land saving: Due to the high value of urban land in general metropolises, the construction of railways underground can save ground space and allow the ground land to be used for other purposes.

Noise reduction: The railway is built underground, which reduces noise on the ground.

Reduced disruption: Because the subway route does not overlap or intersect with other transportation systems (such as surface roads), there is less traffic disruption and a lot of commuting time can be saved.

Energy saving: In the face of global warming, the subway is the best means of public transportation. Due to the stable speed of the subway, it saves a lot of commuting time, makes people happy to ride, and also replaces a lot of energy consumed by driving.

Reduced pollution: The average car uses gasoline or oil as an energy source, while the subway uses electric energy, which has no exhaust emissions and will not pollute the environment.