Construction method of tunnel ventilation opening structure under weak surrounding rock condition

Abstract

The invention discloses a construction method of a tunnel ventilation opening structure under a weak surrounding rock condition, the ventilation opening structure adopts a side expansion type cross connection mode, an excavation section adopts a curved wall or an arched section, a connection channel and a main hole are not interfered in excavation, and a gradual change section does not exist in excavation; the section of the widened belt is the same as the section of the tunnel emergency parking strip, and the emergency parking strip can be used for lining a trolley and a template; active excavation operation is assisted through the connecting channel, the excavation working face of the main hole can be increased, and the construction period is shortened. When the ventilation opening structure is located in weak surrounding rock and needs to enter the main tunnel from the connection channel to assist excavation of the main tunnel, the ventilation opening structure is constructed through the construction method, and good safety guarantee and construction efficiency can be obtained.

Description

technical field [0001] The invention relates to the technical field of tunnel engineering, in particular to a construction method for a tunnel vent structure under the condition of soft surrounding rock. Background technique [0002] Due to the needs of disaster prevention, rescue and driving comfort, most road tunnels must be equipped with ventilation shafts (shafts or inclined shafts) for ventilation. In the underground, the tunnel and the ventilation shaft are connected by a communication channel. The construction method of the tunnel ventilation structure in the prior art is: excavating a certain height above the main hole of the intersection section, sending the wind into the tunnel or extracting the smoke and dust out of the main hole , this construction method mainly has the following shortcomings: [0003] (1) The construction is complicated. It is difficult to excavate and form the intersection at one time, and it is usually necessary to construct the communicatio...

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Problems solved by technology

[0004] (2) High construction risk and low structural safety

Due to multiple excavation interference, it is easy to cause cracking and instability of the excavated support structure; there are many straight wall structures at the intersection, which is not conducive to the structural force, and the structural safety is low

[0005] (3) It is not conducive to the excavation of the auxiliary main hole

The traditional scheme is difficult to realize the free entry and exit of construction vehicles into and out of the main tunnel, making it difficult to serve as an effective auxiliary construction channel for the main tunnel

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