Movable arch changing device of tunnel primary support clearance interfering section and arch changing method thereof

Abstract

The invention discloses a movable arch changing device of a tunnel primary support clearance interfering section and an arch changing method thereof. The device comprises annular counter-force supports and two movable supports. The two movable supports extend in the advancing direction of a tunnel. The two ends of the annular counter-force supports are mounted on the two movable supports correspondingly. A plurality of jacks connected to steel arches supported inside the tunnel in a pressing mode are arranged on the peripheral surfaces of the annular counter-force supports. According to multiple trusses of the annular counter-force supports, every two trusses of the annular counter-force supports are connected through longitudinal connecting rods, and all the jacks on the same truss of annular counter-force supports are used for supporting the same truss of steel arch located in the tunnel correspondingly. According to the arch changing method, dismantling and remaking are conducted alternately so as to complete arch changing construction of each whole sheet of arch, the construction efficiency is high, tunnel arch changing support operation can be conveniently and fast completed, and a safe construction operation environment is provided for tunnel arch changing.

Description

Technical field [0001] The invention relates to the field of tunnel engineering construction, in particular to a mobile arch changing device and an arch changing method for the initial support intrusion section of a tunnel. Background technique [0002] At present, the construction of tunnel engineering generally adopts the new Austrian method, that is, after the excavation of the tunnel, the bearing capacity of the surrounding rock is fully utilized, and the deformation of the surrounding rock is limited by the primary support and the surrounding rock is subjected to force. The secondary lining serves as a strength reserve. After the initial support on the steel arch of the tunnel, due to poor geological conditions, unbalanced pressure, groundwater, inadequate construction organization, etc., it is easy to cause excessive deformation of the vault and side edges during the tunnel construction process, resulting in the initial Lining invasion limit is the phenomenon that the prim...

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Problems solved by technology

[0003] It should be pointed out that the current "arch replacement" method has problems such as complicated construction procedures and prominent safety hazards in terms of intrusion support, demolition and grouting.

For example, in the case of intrusion support, plates, columns, beams, etc. are often used to set up support platforms in the tunnel arch change area to reinforce the primary support in the arch change area. However, the node connections of the old and new rigid frames are weak, and the Poor strength may easily lead to insufficient support strength and affect support safety

When the arch frame is demolished, impact drills or breaking hammers are mostly used to destroy the initial concrete. The lack of support protection for the demolition arch will easily lead to concrete collapse and arch collapse, endangering the safety of construction personnel.

Grouting reinforcement is an effective measure to improve the stability of the surrounding rock, but in many projects, the grouting consolidation is ineffective and even softens the surrounding rock, which is very dangerous when changing the arch of the tunnel

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