JP2003184497A - Tunnel repair method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tunnel repair method capable of repairing a tunnel even if the ground is weak. <P>SOLUTION: This tunnel repair method comprises a drilling step of drilling holes 13 from the inner wall 11 of the tunnel (small section water channel tunnel) 1 to the hard ground 12 of a natural ground 10, a chemical anchor driving step of driving, into the holes, chemical anchors mechanically fixed to the natural ground 10 due to the solidification of resin 32 filled in fine clearances in the inner walls of the holes 13, and a mortar spraying step of spraying mortar 2 on the surface of the inner wall 11 of the tunnel 1. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a tunnel repairing method.

[0002]

2. Description of the Related Art A headrace tunnel having a small cross section with a diameter of 2 to 3 m is used in a hydroelectric power plant or the like when introducing water from a river or the like. In order to withstand the surrounding earth pressure and the internal water pressure inside the tunnel, such a headrace tunnel requires repair work on its cross section during long-term use. For example, in the technique disclosed in Japanese Unexamined Patent Publication No. 11-324587, at the time of performing repair work, mortar containing fibers is pressure-fed by an air pressure feeding pipe, and the liquid quick-setting admixture is slurried in the air pressure feeding pipe. The powdered quick-setting admixture is mixed and sprayed onto the construction surface with a spray nozzle. By using a mortar containing fibers, high strength of the sprayed surface can be obtained both initially and for a long time, and by using a liquid quick-setting agent and a slurry quick-setting agent, the setting immediately after the mortar is sprayed. It also enables the subsequent setting and increase in strength. Also, by doing this, even in a narrow work space such as a small cross section tunnel,
The construction equipment could be downsized, and the amount of dust generated was reduced by reducing rebound such as mortar sagging and rebound.

[0003]

By the way, there is a non-winding tunnel in which the excavation surface is not lined up in the small cross section headrace tunnel. In such a non-winding tunnel, if the mortar and the quick-setting agent are sprayed onto the construction surface in order to repair the location where the ground is weathering, the ground surface of the sprayed surface will collapse. Therefore, before spraying mortar, it is conceivable that the rock bolt is struck and driven into the solid ground inside the ground to reinforce the ground. However, in such a fragile ground, there is a risk that the rock will be driven into the ground and the collapse of the ground will be promoted, which makes it difficult to repair the tunnel. An object of the present invention is to provide a tunnel repairing method capable of repairing a tunnel even on fragile ground.

[0004]

In order to solve the above-mentioned problems, the invention according to claim 1 is a tunnel repairing method, for example, as shown in FIGS. (Hole) from the inner wall 11 of the tunnel 1 to the solid ground 12 of the ground 10 (see FIG. 4), and the resin 32 enters into the minute gaps of the inner wall of the hole 13 and is solidified. 10 is provided with a chemical anchor placing step of placing a chemical anchor 3 mechanically coupled to the hole 10 in the hole, and a mortar spraying step of spraying the mortar 2 on the surface of the inner wall 11 of the tunnel 1. .

According to the first aspect of the present invention, since the boring step and the chemical anchor placing step are provided, it is possible to place the chemical anchor into the bored hole up to the solid ground. Then, the resin enters the minute gaps of the hard ground and is solidified, whereby the chemical anchor is mechanically coupled to the hard ground and the ground is reinforced. Also,
Compared to the lock bolt, the chemical anchor has a tensile strength equal to or higher than that of the lock bolt even if the outer diameter is smaller than that of the lock bolt. Therefore, in the drilling step, a hole having a smaller hole diameter than that of the lock bolt may be drilled. Therefore, even if the rock bolts are placed in the fragile ground where weathering has advanced, and even if the ground collapses on the contrary, chemical anchors are placed to reinforce the ground. It can be carried out. In addition, the chemical anchor is economically superior to the lock bolt, so that the cost can be reduced. After the ground is reinforced, the mortar is sprayed on the surface of the inner wall of the tunnel.Therefore, spraying the mortar does not prevent the base from collapsing and spray the mortar. It can be performed.

The invention according to claim 2 is, for example, as shown in FIGS. 1, 2 and 4, in the tunnel repairing method according to claim 1, from the surface of the inner wall 11 of the tunnel 1 of the chemical anchor 3. A wire mesh 4 is attached to the protruding portion 39, and a wire mesh attaching step of covering the surface of the inner wall 11 of the tunnel 1 with the wire mesh 4 is provided, and the mortar 2 is sprayed onto the surface of the inner wall 11 of the tunnel 1 from above the wire mesh 4. It is characterized by

Here, a well-known wire mesh can be used, and for example, a welded wire mesh or a diamond wire mesh can be used.

According to the second aspect of the present invention, the method further comprises the step of attaching the wire mesh to the protruding portion of the chemical anchor after reinforcing the ground and covering the surface of the inner wall of the tunnel with the wire mesh. Therefore, it is possible to prevent the ground from collapsing. In addition, since the mortar has good adhesion to the wire mesh, even in a headrace tunnel, etc., the humidity inside the mine is high, and even if the mortar is sprayed directly onto the inner wall of the tunnel, it is difficult for the mortar to adhere to the ground. Mortar can be sprayed and attached to the surface of. Furthermore, since the collapse of the ground is prevented by the wire net, by spraying the mortar, it is possible to repair the tunnel without the ground collapse with the mortar from the surface on which the mortar was sprayed. . In addition, since the repair can be performed in this manner, it is possible to prevent the ground from collapsing.

According to a third aspect of the present invention, for example, as shown in FIGS. 1, 2 and 4, in the tunnel repairing method according to the first or second aspect, the mortar 2 contains a fiber-containing fiber. The mortar 2 is characterized by being sprayed on the surface of the inner wall 11 of the tunnel 1 together with the quick-setting agent.

Here, the fibers refer to inorganic fibers such as glass fibers, steel fibers and carbon fibers, olefin fibers, polyvinyl alcohol fibers, other synthetic fibers, organic fibers such as pulp fibers, etc., and have excellent tensile strength. Any fiber that can improve the brittleness such as the tensile strength and the bending strength of the mortar and can improve the toughness may be used. The mortar is mainly contained as short fibers, but may be contained as long fibers. The quick-setting admixture refers to an admixture that mixes in mortar or concrete to accelerate the hydration reaction of cement and that significantly shortens the setting time.

According to the third aspect of the present invention, since the fiber-containing mortar in which the fibers are contained in the mortar is sprayed onto the surface of the inner wall of the tunnel, the mortar such as the tensile strength and bending strength of the sprayed surface of the mortar. Brittleness is improved and toughness is imparted. Therefore, in a tunnel with a small cross section, such as a small cross section tunnel, if the mortar is sprayed thickly, the cross section becomes small. Therefore, even if it is required to spray thin mortar, sufficient strength should be exhibited. You can Further, since the fiber-containing mortar is sprayed on the surface of the inner wall of the tunnel together with the quick-setting agent, the quick-setting property of the mortar is good and the hardening is fast. Therefore, it is possible to reduce the rebound such as the mortar sagging from the spraying surface and the bouncing of the mortar, and it is possible to suppress the amount of dust generated in the mine.

Further, since the amount of dust thus generated can be suppressed, the equipment such as ventilation equipment can be simplified at the time of construction, and the construction equipment as a whole can be downsized. For this reason, it is possible to suppress power consumption during construction, and a small generator can be used. Therefore, repair work can be performed even for a long-distance headrace tunnel with a small cross section formed in a mountainous area where it is difficult to supply power to the inside of the tunnel. Further, even if the cross section is small like a small cross section tunnel, the equipment can be downsized, so that the working space will not be insufficient. In addition, since the mortar is sprayed together with the quick-setting agent after the ground is reinforced, the ground collapses and the mortar cannot be sprayed even when the ground is vulnerable. There is no such thing.

The invention according to claim 4 is, for example, as shown in FIGS. 1, 2 and 4, in the tunnel repairing method according to any one of claims 1 to 3, the tunnel 1 is a small cross-section tunnel. It is characterized by being 1.

According to the invention as set forth in claim 4, in a small cross-section tunnel in which the inner wall of the tunnel is not lined with concrete or the like and is in a non-rolled state, the natural rock is weathered and the natural rock is reinforced. Even in difficult cases, the ground can be reinforced by chemical anchors, and the tunnel can be repaired by spraying mortar.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a tunnel repairing method according to the present invention will be described in detail below with reference to FIGS. In the present embodiment, the tunnel repair method of the present invention is applied to the tunnel boring machine (T
It will be described below as being applied to a small section headrace tunnel (tunnel, small section tunnel) 1 (see FIGS. 1 and 2) excavated by BM). This small-section headrace tunnel 1 is used to introduce water from the intake dam to the hydroelectric power plant, and its diameter d is about 2 m, width w is about 1.73 m, and its total length is about 4 km. It extends to.

The inner wall 11 of the small cross section headrace tunnel 1 has a portion covered with concrete or the like and a non-rolled portion not particularly covered. In addition, the surrounding ground 10 is made of phyllite that has developed a flaky structure, and is thin and easily peeled off. For this reason, the ground is fragile and easily collapses at the weathered portions of the natural ground 10. In the unrolled state where the lining is not lining, the ground 10 is easily affected by weathering, etc. If left unwound, the weathering of the ground 10 will progress and the small cross-section The roughness coefficient inside the waterway tunnel 1 increases, and it becomes difficult for water to flow inside the tunnel 1. Therefore, it is assumed that repair work is performed by the tunnel repairing method of the present embodiment on a section of about 500 m in an unwound state in the middle part of the small cross section headrace tunnel 1.

First, when the repair work for the small cross-section headrace tunnel 1 is performed, the power generation at the power plant is stopped, the water intake is stopped, and the water inside the small-section headrace tunnel 1 is cut off. Then, the materials and the like required for the repair work are carried in from an intermediate carry-in port (not shown) provided in the middle of the tunnel 1.

In this repairing method, first, a washing process is performed to wash the construction surface of the inner wall 11 of the small cross section headrace tunnel 1,
Next, a perforation step of perforating a hole 13 from the inner wall 11 of the small cross section headrace tunnel 1 to the natural ground 10 (see FIGS. 1 and 4) is performed, and a chemical anchor 3 for placing the chemical anchor 3 into the hole 13 is performed. The installation step (see FIGS. 1, 2 and 4) is performed. And the tunnel 1 of the chemical anchor 3
The mortar spraying step of spraying the mortar 2 from above the wire mesh 4 toward the surface of the inner wall 11 of the small cross-section headrace tunnel 1 is performed by mounting the wire mesh 4 on the protruding portion 39 protruding from the surface of the inner wall 11 of I do.

First, in the cleaning step, the mortar 2 adheres to the inner wall 11 of the small-section headrace tunnel 1 so that the mortar 2 adheres sufficiently to the surface of the inner wall 11 of the small-section headrace tunnel 1 onto which the mortar 2 should be sprayed. Rinse away any dust and dirt that is present. Then, in the drilling step, in order to drive the chemical anchor 3, as shown in FIGS. 1 and 2, a predetermined upper and lower two steps are respectively provided from the surface of the inner wall 11 of the small cross section headrace tunnel 1 to the natural ground 10 side. Drill holes at intervals. At this time, the solid ground 12 inside the natural ground 10 is drilled. Then, in order to perform the chemical anchor placing step shown below, the inside of the hole 13 is alternately cleaned with a blower and a brush.

The chemical anchor 3 comprises a chemical capsule 30 shown in FIG. 3 and an anchor bolt (reinforcing rod) 38 (see FIG. 4) inserted into the chemical capsule 30. The chemical capsule 30 includes a brown glass tube 31, and an epoxy acrylate resin 32 is filled in the bottom of the brown glass tube 31.
A hardener 33 is inserted in the central portion of 1. Further, an aggregate 34 is filled around the hardened material 33. A stopper 36 is provided at the tip portion 35 of the chemical capsule 30 to prevent the resin 32, the curing material 33, the aggregate 34, etc. filled in the brown glass tube 31 from spilling. .

In the chemical anchor placing process, first, as shown in FIG.
Is inserted to the bottom of the hole 13. And (2) of FIG.
As shown in (3) and (3), the anchor bolt 38 whose tip is cut obliquely is attached to the electric hammer drill 5 or the like, and is inserted into the hole 13 at the tip portion 37 while rotating and striking the anchor bolt 38. Chemical capsule 30
The brown glass tube 31 of No. 1 is crushed, and the epoxy acrylate resin 32 and the curing material 3 filled inside the glass tube 31
3, Anchor bolts 38 are driven from the inner wall 11 of the small cross-section water conduit tunnel 1 to the natural ground 10 so that the aggregate 34 and the crushed material of the glass tube 31 are mixed. At this time, the tip 37 of the anchor bolt 38 is obliquely cut because the resin 32, the curing material 33, the aggregate 34, etc. filled in the chemical capsule 30 stir at the same time as the anchor bolt 38 is embedded. . By doing so, the resin 32 or the like enters even the minute gaps of the hard rock 12 around the hole 13, and the resin 32 or the like is solidified, so that the anchors as shown in (4) of FIG. The bolt 38 can be firmly and mechanically connected to the solid ground 12 of the ground 10.

Next, in the wire mesh attaching step, as shown in FIGS.
As shown in (4) of FIG. 4, the wire net 4 is attached to the projecting portion 39 of the chemical anchor 38 projecting from the surface of the inner wall 11 of the small cross-section water channel tunnel 1, and the inner wall 11 of the small cross-section water channel tunnel 1 is attached. The surface of is covered with a wire mesh 4.

Next, a mortar spraying process is performed on the inner wall 11 of the tunnel 1 covered with the metal net 4. The mortar 2 is a fiber-containing mortar obtained by mixing ordinary Portland cement, which is obtained by firing a mixture of limestone, clay, silica, etc., and finely pulverizing it, and fine aggregate, organic fibers, an admixture, etc., and water. And Further, the fluidity of the mortar 2 is sprayable and is appropriately adjusted so as to exert sufficient strength. When mixing these, it is advisable to use a mixing pump (not shown) that can mix them and at the same time send the fiber-containing mortar 2 by air.

Then, the mortar 2 is sprayed onto the construction surface of the inner wall 11 of the small cross section water channel tunnel 1 by the spray nozzle attached to the mixing pump. At this time, a storage tank (not shown) for storing the quick-setting admixture that accelerates the hydration reaction of cement is provided separately from the mixing pump, and a pressure feed pipe or a compressor for sending the quick-setting admixture to the storage tank under pressure. Is provided so that the pressure-feeding pipe for pressure-feeding the quick-setting agent merges with the mortar 2 in the spray nozzle. By doing so, the fiber-containing mortar 2 and the quick-setting agent are mixed in the spray nozzle immediately before the mortar 2 is sprayed on the working surface, and the fiber-containing mortar 2 and the quick-setting agent are mixed on the working surface. It will be sprayed at the same time.

According to the tunnel repairing method of the present embodiment, the inner wall 11 of the small cross-section headrace tunnel 1 is in the unwound state in which it is not lined with concrete or the like, and the natural ground 10 is weathered. Even if solid ground 1
The hole 13 drilled up to 2 and the chemical anchor driving step of driving the anchor bolt 38 by inserting the chemical capsule 30 into the hole 13 are provided in the hole 13 drilled up to the solid ground 12. The chemical anchor 3 can be placed. Then, the resin 32 or the like enters the minute gaps of the hard ground 12 and is solidified, whereby the chemical anchor 3 can be mechanically coupled to the hard ground 12, and the ground 10 can be reinforced.

Further, as in the present embodiment, in the natural ground 10 made of phyllite, etc., which is apt to collapse due to the progress of weathering,
When the rock bolt is driven, the natural ground 10 may collapse. However, even when the ground of the natural ground 10 is fragile as described above, the outer diameter of the chemical anchor 3 is smaller than the outer diameter of the lock bolt, and the natural ground 10 does not collapse in the drilling process. Further, even if the outer diameter of the chemical anchor 3 is smaller than the outer diameter of the lock bolt, it is possible to achieve tensile strength equal to or higher than that of the lock bolt, so that the natural rock 10 is reinforced without collapsing. It can be carried out. Further, the chemical anchor 3 is economically superior to the lock bolt, and the cost can be reduced.

Further, the ground 10 is reinforced by the chemical anchor 3 as described above, and then the wire net 4 is attached to the projecting portion 39 of the chemical anchor 3, and the surface of the inner wall 11 of the small cross-section headrace tunnel 1 is attached. Since the step of attaching the wire net to the wire net 4 is provided, it is possible to prevent the ground 10 from collapsing. Further, since the mortar 2 has good adhesiveness with the wire net 4, as in the small cross-section headrace tunnel 1 of the present embodiment, water is normally passed through, so the humidity inside the tunnel 1 is high, and the mortar 2 The inner wall 1 of the tunnel 1
Even if the mortar 2 does not easily adhere to the ground 10 even if it is sprayed onto the ground 1, the mortar 2 can be sprayed and adhered onto the surface of the inner wall 11 of the tunnel 1. Furthermore, the ground 1
Since the collapse of 0 is prevented by the wire net 4, it is 1
Even if the weathering of 0 progresses and the ground easily collapses, it is possible to prevent the natural ground 10 from collapsing together with the mortar 2 from the surface on which the mortar 2 is sprayed.

Further, since the fiber-containing mortar 2 in which the fibers are contained in the mortar 2 is sprayed onto the surface of the inner wall 11 of the small cross-section headrace tunnel 1, brittleness of the mortar 2 such as tensile strength and bending strength is improved. And toughness is imparted. Therefore, even when the cross section of the tunnel 1 is small and the mortar 2 cannot be thickly sprayed and the thin mortar 2 is required to be sprayed as in the present embodiment, the fiber-containing mortar 2 allows the thin mortar 2 to be sprayed. Even a layer can exhibit sufficient strength. Further, since the fiber-containing mortar 2 is sprayed on the surface of the inner wall 11 of the small cross-section water conduit tunnel 1 together with the quick-setting agent, the quick-setting property of the mortar 2 is good and the hardening is fast. Therefore, the mortar 2 may drip from the spray surface of the mortar 2,
The rebound of the mortar 2 such as the bounce of the mortar 2 can be reduced, and the amount of dust generated inside the tunnel 1 can also be suppressed.

Further, since the amount of dust thus generated can be suppressed, equipment such as ventilation equipment can be simplified when carrying out repair work. Also, by mixing pump, ordinary Portland cement, organic fiber,
Since the mixed mortar 2 can be pressure-fed by air while mixing the fine aggregate, water, etc., it is possible to downsize the entire construction facility for repair. Therefore, when performing repair work, power consumption can be suppressed and a small generator can be used. Therefore, as in the small cross-section headrace tunnel 1 of the present embodiment, it is in the mountain area,
Even when it is difficult to supply power to the inside of the tunnel, the tunnel 1 can be repaired, and the labor and cost of having to draw the electric cable inside the tunnel 1 for a long time can be reduced. Further, even if the cross section of the tunnel 1 is small like the small cross section headrace tunnel 1, the equipment for repair work can be downsized, so there is no shortage of working space in the tunnel 1 mine.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that appropriate modifications can be made without departing from the spirit of the present invention. In the present embodiment, ordinary Portland mortar, organic fiber, fine aggregate and water are mixed and sprayed as the fiber-containing mortar 2 onto the surface of the inner wall 11 of the small cross-section headrace tunnel 1.
It is not limited to this, and a normal mortar containing no fiber may be used. Further, in the mixing pump, ordinary Portland cement, organic fiber, aggregate, water and the like are mixed, but it is of course possible to use a commercially available product in which these materials other than water are mixed in advance. .

Although organic fibers are used, the present invention is not limited to this, and inorganic fibers such as glass fibers, steel fibers, carbon fibers and the like may be used, and they have excellent tensile strength. Any fiber capable of improving brittleness such as tensile strength and bending strength of the mortar 2 and improving toughness may be used.

Further, although the quick-setting agent is mixed with the fiber-mixing mortar 2 in the spray nozzle and sprayed on the inner wall 11 of the small cross-section headrace tunnel 1, it is not limited to this. By spraying the quick-setting agent at the same time as the mortar 2, the hydration reaction of the cement was promoted and the hardening of the mortar 2 was accelerated, but if the environment in which the mortar 2 is sufficiently hardened, the quick-setting agent is not used. May be. Further, the mortar 2 and the quick-setting admixture do not necessarily have to be mixed in the spray nozzle. Also, the types of chemical anchors 3 and mortar 2 can be changed as appropriate, and the repair method of this tunnel is not applied only to the small cross section headrace tunnel 1, but to any kind of tunnel repair work. You can do it.

[0033]

According to the first aspect of the present invention, since the boring step and the chemical anchor placing step are provided,
The chemical anchor and the solid ground are mechanically connected to each other, and the ground is reinforced. Further, since the chemical anchor has a smaller outer diameter than the lock bolt, a hole having a smaller hole diameter than that of the lock bolt may be drilled in the drilling step. Therefore, by setting the lock bolt,
Even in the case of fragile ground that is likely to collapse, chemical anchors can be placed to reinforce the ground. In addition, the chemical anchor is economically superior to the lock bolt, so that the cost can be reduced.
After the ground is reinforced, the mortar is sprayed on the surface of the inner wall of the tunnel, so even if the ground is fragile, the mortar can be sprayed without damaging the ground to repair the tunnel. it can.

According to the second aspect of the present invention, the method further comprises the step of attaching a wire mesh to the protruding portion of the chemical anchor after reinforcing the ground and covering the surface of the inner wall of the tunnel with the wire mesh. Therefore, it is possible to prevent the ground from collapsing. In addition, since the mortar has good adhesion to the wire mesh, even in a headrace tunnel, etc., the humidity inside the mine is high, and even if the mortar is sprayed directly onto the inner wall of the tunnel, it is difficult for the mortar to adhere to the ground. Mortar can be sprayed and attached to the surface of. Furthermore, since the collapse of the ground is prevented by the wire net, even if the ground is fragile and weathered, the ground will collapse together with the mortar from the surface onto which the mortar was sprayed, and spray the mortar. You can prevent that you can not,
Can repair tunnels.

According to the third aspect of the invention, since the fiber-containing mortar in which the fiber is contained in the mortar is sprayed on the surface of the inner wall of the tunnel, the brittleness of the mortar such as tensile strength and bending strength is improved. And toughness is imparted. Moreover, since the fiber-containing mortar is sprayed on the surface of the inner wall of the tunnel together with the quick-setting agent,
The mortar has a quick setting property and cures quickly. Therefore, the mortar rebound such as the mortar sagging from the spray surface or the mortar bouncing can be reduced, and the amount of dust generated in the mine can be suppressed. Therefore, equipment such as ventilation equipment can be simplified, and the entire construction equipment can be downsized. Therefore, power consumption can be suppressed during construction, and even if it is difficult to supply power to the inside of the tunnel, the tunnel can be repaired.

According to the invention as set forth in claim 4, in a small cross-section tunnel in which the inner wall of the tunnel is not lined with concrete or the like and is in a non-rolled state, the weathering of the natural ground advances and the natural ground is reinforced. Even in difficult cases, the ground can be reinforced by chemical anchors, and the tunnel can be repaired by spraying mortar.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a tunnel repaired by a tunnel repairing method according to an example of the present invention.

FIG. 2 is a side view showing an inner wall of a tunnel repaired by a tunnel repairing method according to an example of the present invention.

FIG. 3 is a cross-sectional view showing a chemical anchor used by a tunnel repairing method according to an example of the present invention.

FIG. 4 is a diagram showing a procedure of a tunnel repairing method according to an example of the present invention.

[Explanation of symbols]

1 tunnel (small section tunnel, small section headrace tunnel) 10 ground 11 inner wall 12 solid ground 13 hole 2 mortar 3 chemical anchor 32 resin 39 protrusion 4 wire mesh

Claims (4)

[Claims] 1. A method for repairing a tunnel, which comprises a step of boring a hole from the inner wall of the tunnel to a solid ground, and the resin enters into the fine gaps of the inner wall of the hole and is solidified, whereby the rock is grounded. A method for repairing a tunnel, comprising: a chemical anchor placing step of placing a chemical anchor mechanically coupled with the hole into the hole; and a mortar spraying step of spraying mortar onto the inner wall surface of the tunnel. 2. The method for repairing a tunnel according to claim 1, wherein a wire mesh is attached to a protruding portion of the chemical anchor protruding from the surface of the inner wall of the tunnel, and a wire mesh attaching step of covering the surface of the inner wall of the tunnel with the wire mesh. A method of repairing a tunnel characterized by spraying mortar onto the surface of the inner wall of the tunnel from above this wire mesh. 3. The method for repairing a tunnel according to claim 1, wherein the mortar is a fiber-containing mortar containing fibers, and is sprayed on the surface of the inner wall of the tunnel together with a quick-setting agent. Tunnel repair method. 4. The method of repairing a tunnel according to claim 1, wherein the tunnel is a tunnel having a small cross section.