Tunnel maintenance and reinforcement
Tunnel maintenance and reinforcement project construction scheme

I. repair cracks in tunnel lining
For the micro cracks with width less than 0.15mm, the coating sealing method was adopted.
The cracks with a width between 0.15mm and 1.5mm are subjected to automatic low-pressure seepage.
Cracks larger than 1.5mm in width are filled with epoxy mortar.

1. Coating sealing method
Coating the surface of concrete with waterproof coating film to seal the repair method of micro cracks is called coating sealing method, which is applicable to the width of micro cracks less than 0.15mm repair, and used for the decoration of concrete surface and waterproof treatment, at the same time to prevent the carbonization of concrete protective layer and corrosion of harmful ions on concrete.

(1) materials
ZV type concrete repair adhesive, ZB type cover adhesive, repair powder or cement.
(2) repair technology
A, cleaning
The floating slurry and sand layer of the concrete surface layer shall be polished by a grinding wheel grinder and cleaned or rinsed clean.
B. scrape the putty
Concrete surface cracks, air holes and defects should be filled with putty to make up, and polished with emery cloth after drying.
Putty formula: ZV type concrete repair adhesive: powder = 1:1.8 ~ 2.0.
C. Apply the underlying coating
Formula for ZV type concrete repair adhesive: powder =1:0.7 ~ 0.8.
Can use wool roll roll besmear, also can use
Brush or roll and brush once.
The coating should be filtered through iron window screen before use to remove impurities and clumps.
D. Apply the main coating
The main coating formulation is ZV type concrete repair adhesive: powder =1:0.8 ~ 1.
Use brush besmear and roll besmear method besmear besmears brush 3 times, besmear brushs every besmear to want to wait on coating to point to dry again besmear, additional, direction of two besmear brush had better be mutual perpendicular.
E. After the main coating is dried, apply 1-2 layers of ZB type coating adhesive to the outer cover.

2. Pressure grouting method
It is suitable for crack treatment with depth and width greater than 1.5mm. Epoxy resin mortar is used as the material for crack pressure grouting of concrete structure.
Pressure grouting construction must be carried out one by one according to the following technological processes: crack inspection and cleaning, drilling and burying pipe, crack stopping grouting, pressure gas experiment, grouting, finishing treatment and quality inspection.

(1) inspection and cleaning of cracks
Before repair, check and record the cracks in the repaired parts in detail, and make quantitative and qualitative analysis of all cracks in the damaged parts of the structure.
According to this, the specific calculation and arrangement of chemical grouting material proportion, burrow nozzle, grouting injection and so on are carried out.
(2) drilling and burying the nozzle
Mouth is the injection port of chemical grouting material, also be the exhaust port of crack, the principle that mouth arranges is: wide seam is thin, narrow seam is close, break seam crisscross place sets mouth alone.
(3) slurry stop at the seam
The purpose of grouting is to prevent the loss of grout and ensure the grout compacts the cracks under grouting pressure.
(4) air pressure test
Test inspection, that the quality of the joint is good, no leakage phenomenon, can be configured slurry.
(5) grouting
Grouting order should be first calibrated, the principle is: vertical cracks first down and then up;
Horizontal cracks are gradually poured from the low end to the high end;
Through the cracks should be on both sides of a first one after staggered.
Exhaust should be noted throughout the perfusion process.
Before pouring one mouth into the next, a section of transparent plastic hose must be tied on the already filled mouth to prevent it from bending and binding to death when the mouth overflows with slurry.
After grouting or injection, it is best to stabilize the pressure for a few minutes, and do not rush to transfer, so as to make the cracks to be treated as full as possible to eat pulp.
(6) after finishing treatment, the grouting nozzle can be removed one by one after grouting is completed and cured by slurry polymerization, and then the grouting nozzle can be smoothed with epoxy resin cement.
Finally, a layer of epoxy resin cement slurry is applied on the surface of each crack to ensure that the seal is tight and its color is consistent with the original concrete structure as far as possible.

Second, tunnel lining concrete surface defects repair

Before repairing, the concrete on the surface of the concrete damaged area shall be treated, loose concrete shall be chipped away, and the concrete shall be treated and chipped.
If the steel bar is found to be rusted, the steel bar shall be de-rusted.
Clean the concrete surface and keep it wet and clean. M15 waterproof cement mortar is used to treat the concrete surface peeling and cavitation.
Finally, the concrete surface is polished and the uneven places are repaired.

1. Processing methods

(1) surface patching
(2) fill with fine stone concrete
(3) epoxy resin repair

2. Specific measures

(1) surface cleaning method
(2) filling method of fine stone concrete

Third, lining seepage crack seepage water treatment

1. Product introduction

Quick-acting plugging agent is a new type of rigid waterproof plugging material (also known as plugging king, plugging ling).
It is characterized by rapid coagulation and hardening, extremely short initial and final coagulation time interval, and rapid strength generation after final coagulation. The strength is greater than 10Mpa in 15 minutes and 20MPa in 1 hour.
Can carry water operation, and quickly stop water plugging.
This product construction is simple, with the base level adhesive force is strong, does not shrink, does not fall off, can be widely used in housing, underground, tunnel, mine and other engineering leakage stop water, repair, perfusion and so on.
The product is chlorine-free, non-toxic, non-flammable and non-explosive.

2. Governance process

Looking for leaking parts - > in the leaking parts digging u-shaped hole (about 8 cm deep pit, about 5 cm wide) to flush the u-shaped pit, according to the first not leaking cracks repair methods to deal with crack and pressure available plugging agents to stay slurry curing after let go, besmear to brush waterproof coating pressure plastered to besmear to brush waterproof coating, waterproof mortar with waterproof mortar - with epoxy mortar leveling, closed.

3. Use of quick-acting plugging agent

A. Firstly, cut the leaking point or seam into a vertical or beep mouth, clean up the sundries and treat the cracks according to the treatment method of non-leaking cracks;
B. Put the quick-acting plugging agent into the mixing pot and add a certain proportion of water (0.3 ~ 0.35 kg of water can be added according to the quick-acting plugging agent of one kg, or mix according to the product description) to quickly mix into a paste. When the temperature is lower than 5 degrees Celsius in winter, stir with water of 40 degrees Celsius;
C. Put the well-mixed plugging agent cement on your hand. When the cement feels a little hot, press it down the leaking direction quickly.
D. After water shutoff, apply polymer waterproof mortar to the surface and maintain the surface for three days;
E. For the seepage pit, the quick plugging agent dry powder can be directly put into the pit, and then the foot can be stepped on, and the foot can be loosened after hardening;
F. For serious water leakage cracks, first cut drainage holes in the places of serious water leakage to slow down the leakage of other places, and finally block the drainage holes, and then use polymer waterproof mortar to plaster the surface.
G, for a large area of leakage, to find the leakage point, first with quick effect plugging agent blocked, and then with waterproof mortar plaster.

Key words: tunnel maintenance reinforcement tunnel reinforcement tunnel maintenance bridge support replacement