End sealing method of tunnel dual-lining trolley air bag die containing built-in type water-stop belt

Abstract

The invention provides an end sealing method of a tunnel dual-lining trolley air bag die containing a built-in type water-stop belt. The end sealing method is particularly suitable for projects of mountain tunnels, underground railroads, electric heating tunnels and other standard interval tunnels, the air bag die achieves effective fixation along the inner side and the outer side of the circular construction joint water-stop belt, installation and inflation are achieved joint by joint, close attachment is achieved between an air bag and a trolley formwork panel, between the air bag and the water-stop belt and between the air bag and a waterproof board, the size of the inflated air bag is controlled, and it is ensured that the built-in type water-stop belt is centered in the longitudinal and annular directions at a construction joint; after the air bag is installed, through long wooden boards are annularly and densely arrayed at one end of a trolley and fixed with wooden wedges. The method has the advantages of being convenient to operate, high in work efficiency, low in cost, little in pulp leakage and high in pressure bearing.

Description

technical field [0001] The invention relates to a method for sealing the air bag mold of the second-lined trolley of the tunnel with a mid-buried waterstop, which is especially suitable for standard interval tunnel projects such as mountain tunnels, underground railways, and electric and thermal tunnels. Background technique [0002] In my country, the second lining of the arch wall of mountain tunnels, underground railways, electric heating tunnels and other interval tunnel projects basically adopts the trolley formwork support system. Due to the different functions, section sizes and structural thicknesses of the tunnels, and the construction joints are different. First, the sealing methods that lead to the formwork of the trolley are also various. [0003] Construction joints adopt mid-buried waterstops, which are easy to operate and have obvious water-stopping effects, so they are widely used at present. According to the requirements of relevant specifications, when usin...

AI Technical Summary

Problems solved by technology

[0005] Through the summary and analysis of on-site construction, it is known that the existing two methods of sealing the end of the interval tunnel with the second lining trolley with the buried waterstop have the following defects: 1. Both methods require manual filling to the inside or outside of the waterstop A large number of backing boards, due to the limited length of each section of the backing board, is inconvenient to install and remove, and consumes a long time, which is not conducive to the control of the construction progress of the second lining; 2. After the backing board is used for 2-3 times, the surface sticks A large amount of concrete is attached, and there will be a certain shrinkage deformation at the same time, which is not easy to use again and needs to be replaced in time

Therefore, the use of backing plates is not conducive to the cost control of the second lining construction; 3. The first method adopts steel reinforcement welding on the outside of the ring waterstop, which does not form a ring seal. As the concrete continues to be poured, the longitudinal direction of the end formwork As the pressure gradually increases, local expansion or grout leakage is prone to occur on the outside of the waterstop, which will inevitably cause the construction joints of the waterstop to be out of the center. Second lining construction quality control; 4. In the second method, both the inner and outer sides of the waterstop are filled with liner plates. Since the end of the trolley is flush with the edge of the waterstop and the edge of the liner plate, it is difficult to manually align the liner plate and the liner plate. The waterstop exerts hoop pressure, which causes the inner liner plate and the formwork panel of the trolley, the inner and outer liner plate and the water stop, and the outer liner plate and the waterproof plate to be not tightly bonded. During the concrete pouring process, the construction joint There will be a large amount of grout leakage at the place, which will reduce the strength of the concrete in the circumferential construction joint, which will easily cause water leakage in the circumferential construction joint in the later stage, which is not conducive to the quality control of the second lining construction; 5. During the concrete pouring process, especially when pouring to the vault, due The longitudinal pressure that the end formwork can withstand is limited, which often leads to the inconsistency of the concrete pouring of the vault and the phenomenon of local voids. This is also a common quality problem that is prone to occur in the second lining of the arch wall of the interval tunnel.

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