What are the precautions for tunnel lining?

Tunnel lining is a statically indeterminate supporting structure, the main building of the tunnel, simply the inner lining of the tunnel. Its function is to prevent the rock around the tunnel from deforming or collapsing, a permanent support structure built with reinforced concrete and other materials along the tunnel. Lining technology is often used in tunnel engineering and water conservancy channels. The common form is block lining, or it can be prestressed high-pressure grouting plain concrete lining.

        1、The role of tunnel lining

Relatively speaking, the secondary lining and the initial support refer to the inner lining constructed with concrete and other materials under the condition of the initial support of the tunnel, so as to achieve reinforcement support, optimize the route waterproof and drainage system, beautify the appearance, and facilitate the installation The role of communication, lighting, monitoring and other facilities to meet the requirements of modern highway tunnel construction.

The laying of the waterproof board of the waterproof layer of the plastic waterproof board should be ahead of the concrete construction, and the advance distance should be 5-20m, and a temporary baffle should be set to prevent mechanical damage and electric spark burns to the waterproof board. The construction of the secondary lining concrete shall comply with the following requirements: when lashing and welding steel bars, measures to prevent puncture and burning shall be adopted; the concrete outlet and the vibrating rod shall not directly contact the plastic waterproof board.

      2.tunnel lining matters needing attention

1. Before laying the waterproof board, clean the exposed bolt head of the sprayed anchor surface, remove the steel mesh head, apply mortar to cover, and remove and level the severely uneven parts of the supporting surface.
2. The waterproof board is fixed by electric welding bonding method from the arch to both sides, and the gasket is connected tightly to prevent desoldering and exposed welding.
3. The inner and outer steel bars are bound with 4cm thick precast concrete blocks to ensure that the inner side of the steel bars will not cause damage to the waterproof board, and the outer side will not be exposed.
4. Trolley in place: Measure and stake out, set the center line, elevation and width; support the arch wall skeleton, adjust the center line, elevation and width of the skeleton according to the measurement data; install the template, before installing the template, first polish the template; brush off The mold is used as the head plate to reinforce the skeleton; the skeleton positioning is re-tested to detect the thickness of the lining.
5. Before concrete construction, the embedded parts shall be arranged according to the design requirements, holes shall be reserved, and their positions shall be reviewed. Monitor its position and shape changes during the construction process, and take measures to deal with it if necessary.
6. The end stop template of the lining trolley must be closely impacted with the template trolley and the outer arch wall, and the gap between them must be sealed to prevent leakage during the lining construction and affect the quality of the concrete.
7. Construction of delivery pump. Before pouring the concrete, check the delivery pump, put enough lubricating oil, and strengthen the connection with the pouring work in the cave. The pipeline is installed straight and the turn is slow; before pumping, first wet the pipe with a small amount of cement mortar, and then start pouring from far to near ; The pumping process is strictly prohibited to add water or empty the pump; do not stop halfway after the pump is turned on. When changing the pipe, first wet the pipe and then connect it. When the concrete is pumped, blow first and then suck to reduce the pressure in the pipe; when washing the pipe, start from the feed Put a sponge or rubber ball into the mouth, and push out the stock with water.

The above is the relevant content about the role of tunnel lining and the precautions for tunnel lining. Luoyang Gaofeiqiao Tunnel Machinery Co., Ltd. is a modern production enterprise of complete sets of bridge and tunnel construction equipment, integrating design, research and development, production, sales, installation and service. Welcome everyone to leave a message for consultation.