Structure and construction method of arched shed-type composite open tunnel in foundation pit enclosure section of shallow-buried tunnel

Abstract

The invention discloses a shallow-buried tunnel foundation pit support section arch-shaped shed type combination open cut tunnel structure and a construction method and belongs to the field of tunnelstructures. According to the structure, the design boundary portions of the two sides of a tunnel are provided with rows of cast-in-place bored piles in a striking manner correspondingly to serve as side walls of an open cut tunnel; concrete is adopted for being sprayed to the pile walls, located in the open cut tunnel, of the cast-in-place bored piles in each row so as to achieve flat smearing, and the tunnel walls are formed; inverted arches connected with the cast-in-place bored piles into a whole are constructed on the bottom, between the two rows of cast-in-place bored piles, of a tunnelfoundation pit, and earth and stone layers are filled back above the inverted arches; the tops of the cast-in-place bored piles in each row are connected through reinforced concrete crown beams, and aplurality of reinforced concrete transverse supports are connected between the reinforced concrete crown beams of the two rows of cast-in-place bored piles; an arch-shaped top shed is erected on thereinforced concrete transverse supports above the open cut tunnel, and the arch-shaped shed type combination open cut tunnel structure is formed. According to the structure, on the premise of ensuringsafety, space in the tunnel can be enlarged, the view field is open, ventilation and illumination are benefited, and the structure is economical and durable and gives considerations to practicality and attractiveness.

Description

technical field [0001] The invention belongs to the field of tunnel structures, and in particular relates to an arched shed-type combined open-hole structure and a construction method for the foundation pit enclosure section of a shallow-buried tunnel. Background technique [0002] When the buried depth of the tunnel is shallow and the overlying rock and soil mass is thin, and it is difficult to use the underground excavation method, the open excavation method should be used to excavate the tunnel. The tunnel structure built by the open cut method is called open hole. It is more common in the entrance and exit sections of mountainous railways and road tunnels, or the subway interval tunnels in cities in plain areas, as well as the entrance and exit sections of road tunnels and cross-river tunnels. The choice of open tunnel construction method should be determined according to factors such as terrain, geological conditions and structural form. The roof of the cave is genera...

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Problems solved by technology

On site, the monitoring results at the ground crown and beam are generally used to guide the construction, so the monitoring work is not in place theoretically.

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