JPH11293680A - Method for repairing and tree planting on deteriorated mortar-sprayed slope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for repairing and tree planting of a deteriorated mortar-sprayed slope in accordance with the deterioration of an existing mortar- sprayed layer on a slope of the natural ground. SOLUTION: This method for repairing and tree planting of a deteriorated mortar-sprayed slope is provided with processes in which a state of an existing mortar-sprayed layer 12 is investigated and analyzed in advance by an infrared ray diagnostic method. It has a process in which grout 25 is filled into a cavity on a rear surface of the existing mortar-sprayed layer 12, a process in which a hollow bolt or a twisted wire bolt is provided, a process in which a steel fiber reinforced concrete layer 14 is sprayed on the existing mortar-sprayed layer 12, a process in which a root guide hole 26 passing through the steel fiber reinforced concrete layer 14 and the existing mortar-sprayed layer 12 and reaching the natural ground 60 is drilled, a process in which a tree root guiding material is filled into the root guide hole 26, and a process in which a growth ground material layer 16 in which seeds of trees and plants are mixed is sprayed on the steel fiber reinforced concrete layer 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing aged mortar sprayed slopes and a method for afforestation.

[0002]

2. Description of the Related Art A slope (including a slope having an arbitrary slope) sprayed with mortar or concrete (hereinafter, simply referred to as "mortar") may be cracked or damaged with the passage of time, or the back and the ground may be damaged. A cavity is formed between the mountain and the mountain. These will need to be repaired because of the danger of slope collapse.

[0003] The most common conventional repair method is to remove the old mortar spraying layer, remove the old mortar spraying layer, shape the ground, and perform the same mortar spraying work again. In addition, greening works are often performed at the same time in consideration of further stabilization of the slope and the landscape. In addition, it may be combined with a legal framework.

[0004] As a general method of greening the mortar spraying slope, a wire mesh or the like is laid after spraying the mortar, and a thick base material spraying work or a soil seed spraying work is performed from above. For example, Japanese Patent Publication No. 55-42213, Japanese Patent Publication No. 3-68471, Japanese Patent Publication No. 6-99933, Japanese Patent Publication No.
-53997 and the like. Patent No. 26
No. 19297 discloses a method of fixing a vegetation mat by reinforced earthwork.

[0005]

In recent years, there has been a demand for the formation or restoration of natural forests from the viewpoint of environmental conservation as a trend of greening works. Therefore, the main focus of technological development has been shifted from conventional plant-based greening to tree-based planting. The introduction of woody plants to the slope is preferable from the viewpoint of stabilizing the slope as well as the landscape. The same applies to the mortar spraying slope.

However, most of the conventional greening methods for mortar spraying slopes are based on the introduction of herbaceous plants, and a method for reliably introducing woody plants to mortar spraying slopes has not yet been proposed. .

Further, there is a current situation that mortar spraying slopes for which regreening is desired are often deteriorated. It is also important to stabilize the repair of the mortar sprayed slope that has deteriorated for the time being. On the old mortar spraying slope, the weathering of the ground behind the mortar has progressed more than expected, and rainwater has often infiltrated from cracks and exfoliation caused by aging. Even if there is no apparent abnormality, its stability is questionable.

Therefore, in the case of an old mortar sprayed slope, it is necessary to first sufficiently stabilize the slope and then perform greening. Conventionally, the slope stabilization process and the greening process were separately studied and implemented, but this has many problems in various points.

For example, in order to stabilize an old mortar spraying slope, grout is filled in a hollow portion or reinforced with an anchor depending on the situation. When a perforation for elongation is provided in the ground, it is inefficient and uneconomical to perforate a place where thick grouting has been performed. Therefore, it is desirable to carry out comprehensive aging mortar spraying slope rehabilitation work after grasping all the grout filling places, anchor installation places, and drilling places for woody plant introduction from the preliminary survey stage.

[0010] As another example, mortar spraying work is originally a slope protection work that cuts the cut surface from the outside air and rainwater and suppresses weathering by a high hermeticity. Perforations in the layers are frequently performed. Such actions may contribute to instability of the aging mortar spraying slope. If the tree is easily greened without consideration for the stabilization of the slope, it will be difficult to find an abnormality from the outside, which is extremely dangerous.

On the other hand, if greening is performed on the surface of the mortar layer without perforating the mortar layer, the extension region of the plant root system is limited only to the growth base, so that the plant is subjected to a severe water-deficient condition. Depending on weather conditions, it may wither or die.

[0012] In view of the above problems, an object of the present invention is to provide a method for repairing an aged mortar sprayed slope and revegetation, particularly when performing forestation among revegetation works. The aim is to realize an efficient and waste-free construction method by integrating the repair work and forestry construction work in a series of steps in an optimal form. Specifically, it is an object of the present invention to realize a method for improving the water environment by sufficiently securing a region for elongating the root system of the introduced plant while maintaining the stable stability of the mortar spraying slope.

[0013]

Means for Solving the Problems In order to achieve the above object, the first form of the method for repairing the aged mortar spraying slope and reforestation according to the present invention includes the following (1) to (7). Having a process. (1) A step of investigating and analyzing the condition of the existing mortar spray layer in advance by an infrared diagnostic method. (2) A step of filling grout into a hollow portion on the back of the existing mortar spraying layer. (3) A step of installing a hollow rod or a stranded rod to be installed horizontally or upward. (4) A step of spraying a steel fiber reinforced concrete layer on the existing mortar spray layer. (5) A step of piercing a root system guide hole that reaches the ground by penetrating the steel fiber reinforced concrete layer and the existing mortar spraying layer. (6) A step of filling a root induction material into the root induction hole. (7) A step of spraying a growth base material layer in which woody plant seeds are mixed on the steel fiber reinforced concrete layer.

A second embodiment of the present invention is a modification of the first embodiment.
After the steps (1) to (3), the following steps (4) to (9) are provided. (4) A step of piercing a root system guide hole that penetrates through the existing mortar spray layer and reaches the ground. (5) A step of attaching a cover for preventing burial to the root system guide hole. (6) A step of spraying a steel fiber reinforced concrete layer on the existing mortar spraying layer. (7) removing the cover for preventing burial; (8) A step of filling the root system induction hole with a tree root calling material. (9) A step of spraying a growth base material layer mixed with woody plant seeds on the steel fiber reinforced concrete layer.

Preferably, in the step of piercing the root system guide hole, the root system guide hole is pierced so that the hole diameter of the root system guide hole has a conical portion extending from the ground side to the slope surface side.

Preferably, in the step of drilling the root guide hole, the root guide hole is drilled with the axis of the root guide hole being horizontal or inclined so as to be higher on the ground side.

Preferably, in the step of attaching a cover for preventing burial to the root system guide hole, the lid has a lower portion having a portion that can be inserted into the root system guide hole, and an upper portion having an outer shape. It has a conical portion whose diameter increases from the ground side to the slope surface side, and its upper end has a length protruding from the steel fiber reinforced concrete layer to be constructed later.

Further, before the step of filling grout into the hollow portion on the back side of the existing mortar spraying layer, either a spraying method frame work or a combination method of spraying method frame work and anchor work may be performed. . In the case of performing these spraying method frame works or in the case of a relatively stable slope, a soil material may be filled in place of the grout in the hollow portion on the back of the existing mortar spraying layer.

A mortar layer may be used instead of the steel fiber reinforced concrete layer.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings showing construction examples of the present invention. FIG.
It is a sectional view of a slope which shows one example of repair of aged mortar spraying slope and tree construction method of the present invention according to the present invention. A large number of cracks 22 are formed in the deteriorated existing mortar spray layer 12 on the slope of the ground 60, and there are places where cavities 24 are formed by erosion in the ground behind the mortar.

The method according to the present invention can be divided into the following major steps: first, diagnosis or investigation of the ground, second, reinforcement of the slope, and third, greening. Each step will be described in detail. In the first process of diagnosing or investigating the ground, the deterioration state of the existing mortar spray layer and the locations of the cavities and voids on the back thereof are confirmed. This is to obtain basic data for setting an appropriate reinforcement method. Preferably, a preliminary investigation and its analysis are performed by an infrared diagnostic method which is a non-destructive inspection method. The infrared diagnostic method is a method of measuring the temperature of a slope using an infrared camera, and diagnosing a cavity or a deteriorated portion on the back of the mortar from the temperature distribution. Conventionally, diagnosis by hammer percussion has been widely performed, but this method has a problem in terms of safety and efficiency because the diagnosis is performed while a worker hangs on a slope with a rope. In contrast, infrared diagnostics are superior in both safety and efficiency.

Next, a step of reinforcing the second slope is performed. First, in order to ensure the close contact between the deteriorated existing mortar spraying layer 12 and the ground 60, the cavities 24 formed therebetween are formed.
Is filled with grout 25. As the grout, one having fluidity and strength such as mortar is desirable. In the case of mortar, the standard is a water-cement ratio of 50 to 55% and a unit cement amount of 1,250 kg / m ³ .

Thereafter, in order to reinforce the ground 60 on the rear side and remove groundwater, a hollow rod or a stranded rod 20 to be constructed horizontally or upward is constructed. The hollow rod is made of a metal that has been subjected to rustproofing or a hollow rod made of fiber-reinforced resin. The stranded rod has a structure in which moisture is discharged to the surface by capillary action between the stranded wires, and has a surface treatment so that grout cannot penetrate into a painted stranded wire or a carbon fiber stranded wire. The hollow or stranded rod 20 to be installed horizontally or upward is installed for the purpose of reinforcing the ground and supplying water to the vegetation base, and is installed mainly on unstable parts. FIG. 5 is a schematic sectional view showing a preferred structure of a hollow rod or a stranded rod 20 constructed horizontally or upward. The hollow or stranded rod 20 constructed horizontally or upward in FIG. 5 is basically a reinforcing bar,
2 and also functions as a drain pipe. Drill 3 in the ground 60
After providing 1, the hollow rod or the stranded rod 20 to be constructed horizontally or upward is inserted into the perforation 31 and the periphery thereof is filled with mortar or grout 33 to be integrated with the ground 60. A water collecting part 21 filled with a water permeable material is provided at the deepest part of the perforation 31. One or more water inlets 35 are formed at the tip of the hollow rod or the stranded rod 20 constructed horizontally or upward. The water in the ground 60 collected in the water collecting part 21 is introduced from the water inlet 35 into the hollow part 32, passes through the hollow part 32, and is discharged into the drain port 3 on the ground surface side.
Exhausted from 6.

Further, preferably, the hollow rod or the stranded rod 20 which is installed horizontally or upward is inclined at an angle such that the water outlet 36 on the ground surface side is lower than the water inlet 35. The drainage is performed efficiently. The tip of the hollow rod or the stranded wire rod 20 to be installed horizontally or upward must be made of a material that is resistant to corrosion since it is constantly exposed to moisture. On the other hand, the main body of the hollow rod or the stranded rod 20 constructed horizontally or upward except for the distal end is cut off by interposing the water impervious material 34 between the water collecting part 21 and the corroding part due to the penetration of moisture. It also prevents grout from penetrating into the catchment area.

The pitch of the hollow rods or stranded rods 20 constructed horizontally or upward is determined by the scale of collapse assumed for the target slope, but is typically 1.5 m × 1. It is about one every 5 m (about 2 m ² ), and at most about one every 2 m × 2 m.

Further, the deteriorated existing mortar spraying layer 1
In order to reinforce 2, a steel fiber reinforced concrete layer 14 is sprayed on the existing mortar spray layer 12. The steel fiber reinforced concrete is preferably a high-strength mortar having a mixing ratio of steel fibers (steel fibers) of about 1% by volume (about 70 kg / m ³ ). Conventionally, when kneading mortar on site, the construction method is often the air-pumping method, which requires space for material storage places such as aggregates and cement and construction plants, so it is necessary to occupy the road during the construction period was there. Therefore, when such traffic regulation is not preferable, the mortar is not kneaded at the site, but by using ready-mixed concrete, the machine can be removed at night and the entire road can be opened. In this case, the pumping method of the spray material is a pump method. If ready-mixed concrete is used, spraying can be performed only in a very narrow construction space. On the other hand, if there are no restrictions such as traffic regulations,
It is of course possible to perform the construction by the conventional air pressure feeding method.
As another reinforcement example, ordinary mortar may be used instead of steel fiber reinforced concrete.

Next, a third greening process is performed. First,
In order to guide the root system of the woody plant to the ground 60 on the back of the existing mortar spray layer 12, the root system guide hole 2 reaching the ground 60
6. Drill 6 As shown in FIG. 1, the root system induction hole 26 is
Fiber reinforced concrete layer 14 and existing mortar spray layer 12
Penetrates. By providing the root system guide hole 26 reaching the ground 60, the tree root system can enter the ground 60. As a result, the ground 60, the existing mortar spray layer 1
2. The fiber-reinforced concrete layer 14 and the growth base layer 16 formed on the fiber-reinforced concrete layer 14 are connected by a root system, and trees can be formed on a mortar spraying slope.
A preferred method of piercing the root guide hole 26 will be described later in detail with reference to FIG. 2. In the present invention, however, the existing mortar spraying layer 12 is formed with care so as not to impair the advantage of the mortar spraying work excellent in hermeticity. Perforation is being performed.

In addition, the root system of the woody plant was actively
In order to guide the root to zero, the root guiding material 27 having water retention is filled in the root guiding hole 26. The root-derived material 27 may be any material having a water retention property. For example, a polymer water-absorbing resin or other water retention materials can be used. It is also preferable to add an oxygen supply agent such as calcium peroxide.

Next, a growth base layer 16 in which woody plant seeds are mixed is sprayed and formed on the steel fiber reinforced concrete layer 14. As a construction method, for example, vegetation base material spraying or the like can be applied.

At the same time as this growth base formation step, another construction method such as wire mesh tensioning may be used. Existing mortar spraying layer 1
In the case where the ground 60 on the back side of the second is very unstable, the deterrent effect can be improved by using the spraying frame 18 as shown in FIG. 1 together. Also, if a larger scale collapse is expected, it will be dealt with by using anchor works in combination.

The above is the basic form of the method for repairing the aged mortar spraying slope and reforestation method according to the present invention, but various modifications are conceivable according to individual construction conditions.

The cavity 24 of the ground 60 shown in FIG. 1 may be filled with soil instead of grout. This is for the purpose of filling the cavity 24 and appropriately securing the growth space for the induced tree root system. As the soil to be filled, paste of locally generated soil, earth and sand mixed with bentonite, fibrous mixed soil such as bark compost and the like can be used. In the case of soil filling, since the reinforcing function is weaker than in the case of grout filling, the stability of the slope is ensured by using a framing method or a combination of a framing method and anchoring method.

When grout is filled in the cavity, the cracks in the bedrock are also filled with grout, so that the ground strength is increased and the water stoppage is increased. On the other hand, the supply of groundwater is cut off, and the plant is only filled with rainwater. It has the drawback that it has to be relied on and the growth environment is reduced. On the other hand, in the case of soil filling, it is possible to secure a wide growth area of the plant (root elongation area, water supply area) and promote the growth of the plant after afforestation, but the increase in soil pressure and water pressure There is a risk of instability of the slope. Which one to select depends on the situation. For example, when it is determined that the stability of the ground is high and there is no instability factor such as surface collapse, or when the ground is a soil portion and has a stable gradient, soil filling can be applied. Even in such a case, it is desirable to use at least a framing method as a measure for reinforcing the slope.

FIG. 2 is a schematic sectional view showing the shape of the root guide hole 26 formed after the fiber reinforced concrete layer 14 is constructed. The root guide hole 26 is provided so as to reach the ground 60 through the fiber-reinforced concrete layer 14 and the existing mortar spray layer 12. It is preferable that the root system guide hole 26 be drilled at least horizontally or inclined so as to be higher on the ground side, as indicated by the one-dot broken line in the figure. Thereby, root system induction hole 26
The water that has invaded the water quickly moves to the surface side and is drained. As a result, the advantages of the mortar spraying method, which is a closed type construction method for preventing intrusion of water into the back of the mortar and preventing weathering and erosion of the ground, are maintained.

Further, as shown in FIG.
Is preferably formed to have a conical shape with a smaller diameter (L2) on the ground side and a larger diameter (L1) on the growth base layer side. By adopting such a shape,
A tree root system can be efficiently guided from the growth base layer to the root system induction hole.

FIG. 3 is a schematic sectional view of a slope showing another construction example of the present invention. In FIG. 3, the root guide hole 26 is formed before the spraying of the fiber reinforced concrete layer 14. That is, after completing the step of reinforcing the slope, the root system guide holes 26 are formed in the existing mortar spray layer 12. Also in this case, in order to secure favorable drainage conditions, it is preferable that the axis of the root system guide hole 26 is bored by being inclined so that the ground side is higher. In the example shown in the figure, the root system guide hole 26 is a cylindrical hole because the drilling operation is easy. However, similarly to the above-described example, a conical portion in which the hole diameter increases from the ground to the slope side may be provided. Good. Next, the burial prevention cover 28 is inserted into the root system guide hole 26 to cover the root. This is to prevent the root guide hole 26 from being buried when the fiber reinforced concrete layer is sprayed. The lower portion of the burying prevention lid 28 has a cylindrical shape that can be inserted into the root system guide hole 26, and the lower end surface 28a is closed. Furthermore, the burial prevention lid 28
When the fiber reinforced concrete layer 14 is formed, this layer 1
4 so that its upper end 28b projects sufficiently. The shape of the burying prevention lid 28 may be a simple columnar shape as a whole, but it is more preferable to provide a conical portion 28c whose outer diameter expands from the ground side to the slope surface side as shown in the illustrated example. is there.

After the burying prevention lid 28 is attached, the fiber reinforced concrete layer 14 is spray-formed. After that, when the burial prevention lid 28 is removed, the fiber reinforced concrete layer 14 also has an inclined through-hole communicating with the pre-drilled root guide hole 26. Moreover, as shown in the figure, if the burial prevention lid 28 has a conical portion that expands upward, it becomes a through hole having a large opening on the growth base side, and from the growth base layer to the root system induction hole as in the above-described example. And a tree root system can be efficiently induced.

As shown in FIG. 3, according to the construction method of drilling the root guide hole 26 before the fiber reinforced concrete layer 14 is constructed, the drilling work of the root guide hole 26 becomes extremely easy.
In this step, if the burial prevention cover 28 is directly inserted into the root guide hole 26, the fiber-reinforced concrete may be fixed and difficult to remove. It is desirable to insert with a separating material 30 made of a cloth or a material having good releasability. Thereby, the burial prevention lid 28 can be easily removed.

FIG. 4 is a view showing the appearance of the burial prevention lid 28 shown in FIG. It is preferable to have a hollow structure in order to reduce the weight. The upper portion A is a portion exposed upward from the steel fiber reinforced concrete layer, and therefore may have a length that can be easily pulled out by human power. Irregularities serving as clues may be provided on the periphery to facilitate pulling out. The portion B whose diameter increases upward corresponds to a portion buried in the steel fiber reinforced concrete layer, and is set according to the thickness of the layer. The lower portion C is a root system guide hole 26 which is pre-drilled.
Since it is a portion to be inserted into the device, the length is set to such a size that it does not easily fall off. In addition, the diameter D of the lower end face is the root system induction hole 2.
Although it is set to a size that can be inserted into 6, the clearance for interposing a separating material is also considered. In this example, the lid is a container-shaped burying prevention lid having a closed lower end face, but may have a closed upper end face.

In the construction example shown in FIG. 3 as well, even if a construction method using a framing method or a combination of a framing method and an anchoring method is carried out before the step of filling grout into the hollow portion on the back side of the existing mortar spraying layer. Also, the soil may be filled in the hollow portion on the back side of the existing mortar spraying layer.

[0041]

As described above, according to the present invention, first of all, after accurately grasping the present condition of the aged mortar spraying slope, the reinforcement is carried out based on an appropriate construction design for reinforcing the ground, and then the reinforcement is performed. Afforestation is performed without impairing the high hermeticity and stability of the mortar sprayed slope, and in the afforestation process, a sufficient elongation area of the root system of the introduced plant is secured and a good water environment is realized.

As described above, according to the present invention, in the repair of the aged mortar spraying slope and the afforestation method, the advantages of each of the construction steps from the preliminary inspection to the afforestation work are utilized, and a consistent construction in an optimum form is performed. I realized what I did. As a result, efficient slope forestation without waste was made possible, and an excellent construction method was provided from the viewpoint of both disaster prevention and environmental conservation.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a slope showing schematically one example of repairing an aged mortar spraying slope and reforestation according to the present invention.

FIG. 2 is a schematic cross-sectional view showing a shape of a root guide hole that is drilled after construction of a fiber-reinforced concrete layer in the construction example of FIG.

FIG. 3 is a schematic sectional view showing another construction example according to the present invention and showing a construction method in a case where a root system guide hole is drilled before construction of a fiber reinforced concrete layer.

FIG. 4 is a view showing an appearance of a preferred example of a burial prevention lid of the construction example of FIG. 3;

FIG. 5 is a schematic sectional view showing a preferred structure of a hollow drainage lock bolt used in the present invention.

[Explanation of symbols]

12 Existing Mortar Spraying Layer 14 Steel Fiber Reinforced Concrete Layer (or New Mortar Spraying Layer) 16 Growth Base Layer 18 Legal Construction 20 Hollow Rod or Stranded Rod Installed Horizontally or Upward 21 Water Collector 22 Crack 24 Cavity 25 Grout 26 Root system induction hole 27 Root system induction material 28 Buried prevention cover 30 Separation material 60 Ground mountain

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiroshi Yoshida 5--11-3 Shimbashi, Minato-ku, Tokyo Toko Construction Co., Ltd.

Claims (8)

[Claims] 1. A method of repairing an aged mortar spraying slope and afforestation in accordance with the deterioration of an existing mortar spraying layer on a slope of a ground. A step of investigating and analyzing the state of the spraying layer, (2) a step of filling grout in a hollow portion on the back of the existing mortar spraying layer, and (3) installing a hollow rod or a stranded wire rod to be constructed horizontally or upward. (4) a step of spraying a steel fiber reinforced concrete layer on the existing mortar spray layer, and (5) a root system that reaches the ground through the steel fiber reinforced concrete layer and the existing mortar spray layer. Drilling a guide hole, (6) a step of filling a root system induction material in the root system induction hole, and (7) a growth base material layer obtained by mixing woody plant seeds on the steel fiber reinforced concrete layer. With spraying process Repair and trees of method of aging mortar spraying method surface, wherein Rukoto. 2. A method for repairing an aged mortar spraying slope and afforestation with the aging of an existing mortar spraying layer on a slope of a ground, wherein (1) the existing mortar is previously determined by an infrared diagnostic method. A step of investigating and analyzing the state of the spraying layer, (2) a step of filling grout in a hollow portion on the back of the existing mortar spraying layer, and (3) installing a hollow rod or a stranded wire rod to be constructed horizontally or upward. (4) a step of piercing a root system guide hole that penetrates the existing mortar spray layer and reaches the ground, (5) a step of attaching a cover for preventing burial to the root system guide hole, ) A step of spraying a steel fiber reinforced concrete layer on the existing mortar spray layer, (7) a step of removing the cover for preventing burial, and (8) a step of filling a root induction material in the root induction hole. (9) On the steel fiber reinforced concrete layer Spraying a growth base material layer containing a mixture of woody plant seeds to the mortar, and repairing the aged mortar spraying slope and reforestation. 3. The method according to claim 1, wherein in the step of drilling the root system guide hole, the root system guide hole is drilled such that the root system guide hole has a conical portion extending from the ground side to the slope surface side. Or the method of repairing the aged mortar spraying slope and the forestation method according to 2. 4. The method according to claim 1, wherein in the step of drilling the root system guide hole, the axis of the root system guide hole is drilled horizontally or with the ground side inclined as high as possible.
4. The method for repairing aged mortar spraying slopes and the method for afforestation described in any one of the above items 3 to 3. 5. In the step of attaching a cover for preventing burial to the root guide hole, the lid has a lower portion having a portion that can be inserted into the root guide hole, and an upper portion having an outer diameter closer to the ground. 5. A conical portion extending from the front surface to the slope surface side, and an upper end of the conical portion has a length protruding from a steel fiber reinforced concrete layer to be applied later. 5. Repair of aged mortar spraying slope and forestation method as described. 6. The method according to claim 1, further comprising a step of performing a spraying method or a combination of a spraying method and an anchoring method before the step of filling grout into a hollow portion on the back surface of the existing mortar spraying layer. A method for repairing aged mortar sprayed slopes and reforestation according to any one of claims 1 to 5. 7. The method for repairing aged mortar spraying slope according to claim 6, further comprising the step of filling the hollow portion on the back side of the existing mortar spraying layer with soil material in place of the grout. Forest conversion method. 8. The method according to claim 1, wherein a mortar layer is used instead of the steel fiber reinforced concrete layer.