Tunnel reinforced concrete two-lining explosion-control dismantling charging structure and construction method

Abstract

The invention provides a tunnel reinforced concrete secondary lining explosion control dismantling charging structure and a construction method, and is characterized in that blasting sections are symmetrically arranged on haunches and side walls on two sides of a secondary lining, five vertical sections are arranged on the haunches, and drill holes in each section are parallel and inclined upwards; wherein the side wall is provided with four flat sections, and drill holes in each section are parallel and incline towards the outer side of the tunnel. Concrete with the thickness of 3 cm is reserved at the bottom of the drill hole to serve as a protective layer, and a discontinuous interval charging structure is adopted in the hole. And the detonating sequence is that the haunch blast holes on the two sides are detonated firstly, then the side wall blast holes on the two sides are detonated after delaying for half second, and the adjacent blast holes in the longitudinal direction of the tunnel are delayed for 100 ms. The principle is as follows: concrete in a blasting area is easily fragmented by adopting dense blast holes and an interval charging structure, and the concrete fragments are stripped from reinforcing steel bars to form a weak area; and the vault secondary lining concrete in the non-explosion section overcomes the supporting force of the reinforcing steel bars in the weak area of the haunch to fall down, and drives the arch wall in the non-explosion section to flex down around the weak area of the side wall until the secondary lining concrete falls to the ground. The method is suitable for dismantling the tunnel reinforced concrete secondary lining.

Description

technical field [0001] The invention belongs to a method for dismantling a secondary lining structure in the technical field of tunnel construction, and specifically relates to a controlled blasting dismantling charge structure and a construction method for a reinforced concrete secondary lining of a tunnel. Background technique [0002] During the construction and operation of the tunnel, due to engineering quality defects or poor geology, the secondary lining concrete may not be able to resist the pressure of the surrounding rock, resulting in deformation, cracking, or even damage. Commonly used tunnel secondary lining concrete includes plain concrete and reinforced concrete. When it needs to be dismantled and replaced due to damage, because there is no steel skeleton in the plain concrete secondary lining structure, it is relatively easy to dismantle. When the reinforced concrete secondary lining is removed, the difficulty of the operation will be greatly increased due t...

AI Technical Summary

Problems solved by technology

When damage occurs and needs to be dismantled, demolition is relatively easy because there is no steel skeleton in the plain concrete secondary lining structure

When the reinforced concrete secondary lining is removed, the difficulty of the operation will be greatly increased due to the involvement of the steel skeleton in the secondary lining concrete structure. When the traditional weak loosening blasting is used, the surrounding primary support and surrounding rock will be greatly disturbed, which will easily cause secondary disasters; When the broken head is used for demolition, the work efficiency is low and the safety risk is large

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