Tunnel construction methods

Answer analysis of tunnel construction methods include: (1) New Austrian method: is the abbreviation of the new Austrian method of tunnel construction, it is from the point of view of rock mechanics and put forward a reasonable construction method, is the use of anchor spraying technology, monitoring and measuring and the theory of rock mechanics constitutes a system formed by the formation of a new engineering and construction methods. The basic principle of Xin'ao method is: "less disturbance, early anchor spraying, diligent measurement, tight closure". (2) Traditional mine method: a construction method that uses drilling and blasting method of excavation and support of steel and wooden components. (3) Tunnel boring machine method: it is equipped with a rock-breaking cutter, the use of mechanical rock-breaking method of excavation tunnels, and will be crushed stone ballast transmission out of the machine of a kind of excavation and ballast joint operation of the boring machinery, can be continuous digging. (4) Shield method (Shield): it is a kind of steel movable protection device or movable support, it is a kind of machinery that constructs tunnel through the soft aquifer, especially under the river bottom, under the sea bottom, and in the center of the city. Under its cover, the head can safely excavate the strata, boring in one pass the equivalent of the width of one ring of the assembled lining. The tail can be assembled with prefabricated pipe sheets or blocks, which can be quickly assembled into a permanent tunnel lining, and the void between the lining and the soil layer can be filled with cement compression slurry, preventing the continued deformation of the surrounding strata and the growth of the pressure of the surrounding rock. (5) Open cut method: it refers to the construction method of digging up the ground, excavating the earth and rock to the design elevation from the top to the bottom, then constructing the tunnel from the bottom to the top, completing the main structure of the tunnel, and finally backfilling the pit or restoring the ground. (6) Cover Excavation Method: After excavating from the ground down to a certain depth, the top will be closed, and the rest of the lower works will be carried out under the closed roof, and the main structure can be constructed in accordance with the work or against the work. (7) Shallow buried concealed excavation method: it is a comprehensive construction technology with reference to the basic principle of Xin'ao method, which adopts a variety of auxiliary construction measures to reinforce the surrounding rock in the excavation, fully mobilizes the self-supporting capacity of the surrounding rock, and timely supports and closes into a ring after excavation, so that it can form a joint support system with the role of the surrounding rock*** and effectively inhibit the excessive deformation of the surrounding rock. (8) underground diaphragm wall: also known as concrete underground wall, continuous wall in the ground. It is a segmental construction unit underground wall connected to a continuous underground wall, instead of the traditional wood pile, steel pile, reinforced concrete pile, etc., to retain soil, load-bearing, waterproof role. The correct option for this question is "AD".