Tunnel secondary lining reinforced concrete section end formwork structure and mounting method

Abstract

The invention discloses a tunnel secondary lining reinforced concrete section end formwork structure and further discloses a mounting method of tunnel secondary lining reinforced concrete section endformworks. The tunnel secondary lining reinforced concrete section end formwork structure comprises secondary lining longitudinal steel bars (52), arc-shaped end formworks (2), middle-buried water stopping belts (4) and middle-buried water stopping belt fixing devices (51). A middle-buried water stopping belt reserved clamping groove (24) and end formwork longitudinal steel bar reserved holes (23)are formed in each arc-shaped end formwork (2); each middle-buried water stopping belt fixing device (51) comprises hooks on the two sides and a U-shaped groove; one end of each secondary lining longitudinal steel bar (52) is arranged in the corresponding end formwork longitudinal steel bar reserved hole (23); the hooks are arranged on the secondary lining longitudinal steel bars (52) in a winding mode; and the outer sides of the middle-buried water stopping belts (4) are arranged in the middle-buried water stopping belt reserved clamping grooves (24), and the inner sides of the middle-buriedwater stopping belts (4) are arranged in the U-shaped grooves. According to the tunnel secondary lining reinforced concrete section end formwork structure, the middle-buried water stopping belts arefixed through the secondary lining longitudinal steel bars and the middle-buried water stopping belt fixing devices, and the mounting precision, the mounting smoothness and the exposed width of the water stopping belts are ensured.

Description

technical field [0001] The invention belongs to the technical field of the second lining of the tunnel, and more specifically relates to an end formwork structure and an installation method of the reinforced concrete section of the second lining of the tunnel. Background technique [0002] At present, composite lining is widely used in tunnel engineering in my country. According to the design concept of the New Austrian Method, the secondary lining is a molded concrete or reinforced concrete lining applied on the inner side of the primary support, and forms a composite lining together with the primary support. [0003] On the one hand, due to the construction process of the second lining, most of them have a cycle of 8-12 meters, so there are circumferential construction joints, and a circumferential mid-buried waterstop is set at the circumferential construction joints. The installation quality of the waterstop has a great impact on the tunnel Waterproofing plays an importa...

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Problems solved by technology

[0004] Due to the inaccurate reserved position of the waterstop, inconsistent circumferential position, and different reserved depths and widths, it often occurs that the waterstop is completely buried in the concrete or completely falls off. The buried waterstop needs to be bent and fixed. Coupled with subsequent construction (such as demolition of the formwork), it is easy to damage the waterstop, and the waterstop is damaged and broken, and the concrete at the end is prone to quality problems such as pockmarked honeycomb and other quality problems, thus losing the waterstop effect

[0005] On the other hand, the traditional two-lining end formwork is assembled with wooden formwork to form a complete two-lining structure. After the assembled wooden formwork is sealed, the gap is large, which not only easily causes cement grout leakage and loose concrete at the circumferential construction joints, affecting The quality of the concrete at the end, and the slurry flowing out from the joints of the wooden formwork is likely to pollute the front inverted arch side wall, and it is difficult to clean; in addition, the end formwork of the traditional second lining is close to the side of the initial support. The surface of the surrounding rock on the surface of the concrete is not smooth, and the installation process of the traditional wooden formwork needs to be adjusted repeatedly, which is inefficient, and the number of turnovers of the wooden formwork is small, and the loss of each cutting wear is large; The unevenness of the surrounding rock surface on the surface of the sprayed concrete will also cause the problem of grout leakage

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