Subway construction method:
1, Cover Digging: Generally, when the ground conditions permit, subway tunnels should be covered by digging, but it has a great impact on the social environment and is only suitable for places with few people, many cars and few pipelines.
2.NATM: Using NATM principle to build subway has become a major construction method in China. Under the conditions of limited construction site, complex and changeable formation conditions and complex underground engineering structure, it is particularly important to use NATM for construction.
3. Shallow excavation method: also known as mining method: it is a new method developed by NATM after years of improvement and development. Compared with the open cut and cover excavation method, it can avoid the interference of the open cut and cover excavation method on the surface, and has stronger adaptability and flexibility to the stratum. Shallow-buried excavation method is a technical method suitable for building tunnels with small surface subsidence under the condition of loose soil surrounding rock in urban areas, and the buried depth of the tunnel is less than or equal to the tunnel diameter.
Its outstanding advantages are: no influence on urban traffic, no pollution and noise, and it is suitable for tunnel cavities of various sizes and sections. The core technology of shallow-buried underground excavation method is summarized as the policy of 18: pipe entry, strict grouting, short excavation, strong support, quick closure and diligent measurement.
4. shield method shield method: it is a construction method to build a tunnel under the protection of shield.
It is characterized by stratum excavation, excavation and transportation, lining assembly, joint waterproofing, grouting to fill the gap at the tail of shield, draining groundwater at any time and controlling ground subsidence. It is a construction method with high technical requirements and strong comprehensiveness.
It can be excavated in various soft soil strata and soft rock strata, and it has little influence on the surrounding dense environment when crossing the area where buildings and underground pipelines are concentrated, especially suitable for urban subway and underwater tunnel excavation.
5.TBM method: TBM is short for tunnel boring machine, which is driven by machinery, so it is called TBM.
Generally, TBM is defined as a shield machine which is driven by rock strata and equipped with a wall-touching anchor when the full-face tunnel boring machine does not have the functions of maintaining the working face such as earth pressure and water pressure, and is propelled by reaction force during propulsion. Full-face tunnel boring machine (TBM) has been widely used in tunnel excavation abroad because of its advantages such as fast construction speed, good tunnel forming, high degree of mechanization and little impact on the surrounding environment.
Extended data:
EPB shield machine used in urban subway construction has a diameter of more than 6m, and its daily cost is about 35 million, and its cost in Germany is nearly 40 million. The difference in equipment configuration at different prices can reach several million. If it is a mud shield machine, the cost will be higher. In addition, the larger the diameter, the more expensive the price, and the higher the price of TBM. Shield machine leasing is mostly based on the number of meters of excavation, and the total price is uneconomical. One meter is about 7500 yuan, of course, it also depends on the geological conditions. Subway construction is more complicated and the price will be higher. I heard that the blade of shield machine is 60 million, and it needs to be replaced after 6 kilometers of excavation. The cost is 654.38 million kilometers, and
References:
Baidu encyclopedia shield machine