Through the knowledge collation of the architectural knowledge column of this website, Zhong Da Consulting has made the following basic understanding of the subway tunnel project:
Subway tunnel is a kind of tunnel, which refers to an engineering building buried in the stratum and a form of human using underground space. Tunnels can be divided into traffic tunnels, hydraulic tunnels, municipal tunnels and mine tunnels.
In order to help relevant personnel further understand the relevant contents of subway tunnel excavation, Zhong Da Consulting has compiled the relevant matters needing attention in subway tunnel excavation, which are basically summarized as follows:
The full name of shield machine is shield tunnel boring machine, which is a special engineering machinery for tunnel excavation. Modern shield machine has the functions of excavating and cutting earth and stone, conveying earth and gravel, assembling tunnel lining, surveying and guiding rectification, etc., forming a spacious underground cement tunnel through which the shield machine passes.
The shield machine body is welded by thick steel plate, which bears the pressure of the surrounding soil layer and creates a working face for tunneling. Its front end cut is equipped with a large slow-rotating disc with many fast-rotating knives on it. Its shape is not like a drill bit, but more like the head of a Philips razor. At the tail of the shield machine, the tunnel is assembled with tunnel lining segments (prefabricated parts for building tunnel walls), and concrete is poured into the gap between the lining and the shaft wall to reinforce the tunnel and prevent groundwater from infiltrating. The deformer uses the power of the jack to push forward. When the shield machine reaches a certain distance, its thrust can be borne by the friction between the tunnel lining and the stratum. In the cement tunnel formed by shield tunneling, two rails were immediately laid, one for transporting slag and gravel, and the other for transporting lining segments and concrete.
When the shield machine encounters loose soil or groundwater in front, the shield machine will use refrigeration technology to freeze the loose soil or groundwater in front of the cutter head, thus breaking the ice. Therefore, the shield machine is also suitable for excavating cross-river or submarine tunnels.
The process of digging a subway tunnel is as follows: first, dig a big deep pit on the platform, install a shield machine in the deep pit, and then start digging. In order to speed up the process of subway construction, two shield machines can be used to excavate between the two platforms.
Shield machine can improve the efficiency of subway underground excavation by 8 to 10 times, and there is no need for large-scale ground demolition in the construction process, no traffic jam, no noise during construction, no ground subsidence and no impact on the normal life of residents. Large shield machine has high added value and complex manufacturing process. Only a few enterprises in Europe, America and Japan can develop and produce, and the price of each machine is about 654.38 billion RMB. Now there are domestic shield machines, each of which is about 3 thousand, which greatly reduces the cost of subway construction.
For more information about bid writing and improving the winning rate, click on the bottom customer service for free consultation.