Study On Interior Support System For Metro Station Constructed By Expanding Shield Tunnels

Recently, shield method which has high construction speed, safety and small influence for surrounding environment have been widely used in the construction of city metro engineering in our country. But now the construction method of metro station are cut and cover method and mining method, the construction contradiction between metro station and sectional shield tunnel become more evidences, which include inconsistent speed and method, so the advantage of long distance driving of shield method haven't been exerted sufficiently. After consulting experience from overseas and combining the case of construction of shield method used in our country, this paper study the interior support system based on the synthetical technology problem about expanding-building station combining shield method.Based on the analysis of the present state of interior support technique on the expanding excavation of sectional shield tunnel in and out of the country, regarding Beijing metro as project background, taking 6m diameter reinforced concrete segment shield tunneling as premise and satisfying construction's need, this paper design the interior support scheme with six part steel structure and the vertical pole on the cut and cover vertical pole station. The rationality and applicability of the scheme are validated on the side of force and deformation after canculation and analysising the whole key step of struction. For the construction of mining pylon metro station, this paper design interior support scheme with pile, prestressed wire and vertical pole. Prestressed position, prestressed value, prestressed load style and prestressed opportunity were caculated and analysised. What is more, special segment was designed for the prestressed technology. After calculation and anslysis of scheme, the rational style of interior support system was designed and will instruct for later construction.