Non-disturbance type supporting structure used for tunnel vault collapsed cavity processing

Abstract

The invention discloses a non-disturbance type supporting structure used for tunnel vault collapsed cavity processing. The supporting structure comprises a concrete reinforcement net layer laid on a wall face of a collapsed cavity and a protection arc erected along the fracture surface of the collapsed cavity. The protection arc is arranged under the concrete reinforcement net layer. Multiple support pieces are arranged between the protection arc and the concrete reinforcement net layer. The space between the arc back of the protection arc and the inner wall of the concrete reinforcement net layer is filled by arch back backfill layers. Compared with the new Austrian tunneling method, the supporting idea is more advanced by following the principle that surrounding racks and lining structures bearing load together, so the lining structures are allowed to actively participate in load bearing to the greatest extent. The wall face of the collapsed cavity will not be nearly disturbed in the implementation process, so construction risks in the collapsed cavity processing process and potential operation risks are reduced.

Description

technical field [0001] The invention relates to the field of tunnel engineering construction, in particular to a non-disturbance support structure used for tunnel vault collapse cavity treatment. Background technique [0002] Landslide is a typical accident with high occurrence rate in the process of tunnel construction. Except for a few roof-caving landslides (mostly occurring at the entrance of the cave or the shallow buried section of the cave body), the most common landslide on site is the cavity-type landslide, that is, a cavity is formed outside the contour line of the tunnel excavation due to the landslide at the vault. (commonly known as "collapse cavity"). According to the height of the collapse cavity, it can be roughly divided into: small collapse cavity, with a height of about 1-3 meters; medium-sized collapse cavity, with a height of about 3-5 meters; and large collapse cavity, with a height of more than 5 meters. [0003] The treatment of tunnel collapse main...

AI Technical Summary

Problems solved by technology

[0021] 2. Excessive roofing has the risk of expanding landslides

The original intention of finding the roof is to clear the dangerous rocks on the top of the cave, but its severity is difficult to grasp; if it is not handled properly, it is easy to cause secondary landslides, or even multiple landslides, and a vicious circle of "clearer and more collapsed" will occur, which will cause danger to personnel and machinery. cause damage, cause delay

[0022] 3. Drilling disturbs the surrounding rock of the cavity wall, and there are safety risks in the construction process

During the period (about 3 to 5 hours) from the drilling of the hole to the time before the backing plate of the bolt is installed, the drilling actually increases the crack probability of the original surrounding rock block and weakens the connection strength between the blocks; at the same time , under the vibration induction of bolting and drilling, the originally stable rock wall of the collapsed cavity is easy to induce new collapses

[0023] 4. Construction quality is difficult to control

Compared with the situation of setting anchor rods in the caverns after normal blasting and slag removal by workers in the caverns, because most of the cavern walls are extremely irregular, the vault caverns are high, and the working environment in the caverns is poor, construction There is a certain amount of psychological pressure during the process, especially if another landslide occurs during the processing process, the inner burden will be heavy, and even the fear of entering the cave for work will arise, which will lead to a hasty handling of the collapse cavity, and it is difficult to guarantee the construction quality

[0024] 5. The concept of support is contrary to the new Austrian law, and there are safety risks during operation

The stability and durability of the wall of the collapse cavity depend entirely on the stability of the surrounding rock itself and the quality of the treatment and construction of the cavity wall. The tunnel support structure basically cannot share the load; Back, the tunnel structure can only passively withstand the impact load several times its own weight, which will affect the structure and the safety of driving in the tunnel in severe cases

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