JP6253507B2 - Repair and reinforcement bolts and repair and reinforcement methods using them - Google Patents

Description

  The present invention relates to a bolt (so-called “shear bolt”) used for repairing / reinforcing concrete structures such as slopes to which concrete has been sprayed, and repair / repair of a concrete structure performed using such bolts. Reinforcement method.

Various types of shear bolts used in concrete structures (including slopes to which concrete is sprayed) and repair / reinforcement methods using shear bolts have been conventionally proposed (for example, Patent Document 1, Patents). Reference 2).
However, in the conventional shear bolt, the petal nut is tightened after the nut on the side close to the double washer is tightened. For each shear bolt, the process of attaching the existing nut to the existing concrete layer and the process of attaching the petal nut in place It is necessary to perform a process. Therefore, a great amount of work labor is required, and a long time is required for the work time.
On the other hand, it is conceivable to shorten the work time by using an electric tool to reduce the work effort, but the petal nut needs to be positioned at an appropriate position on the bolt (determined according to the spraying thickness). There is a power tool, and the petal nut is tightened at a stroke until it comes into contact with the lower nut. Therefore, if the power tool is used, the petal nut cannot be positioned at an appropriate position of the bolt.

In the shear bolt according to the prior art, if the second nut is engaged in the middle of the bolt in order to position the petal nut in place, the petal nut can be positioned on the bolt (the second nut) even when the electric tool is used. Stops at the position where the bites. However, in this case (when the second nut is bitten in the middle of the bolt), the lower nut near the existing concrete layer (the nut near the double washer) cannot be tightened.
Thus, with the shear bolt according to the prior art, it cannot be tightened at once with the electric tool.

In addition, in a spraying work site where shear bolts are used, the worker hangs on the lifeline, but the lifeline or the operator's foot hits the petal nut and the petal nut turns. As a result, in the shear bolt according to the prior art, the petal nut may turn off before the spraying is performed. For this reason, in the shear bolt according to the prior art, it is necessary for an operator to hit the upper end of each shear bolt with a hammer to crush the screw thread at the site, thereby preventing the petal nut from rotating.
However, enormous effort is required to crush the thread by hitting the upper end of each shear bolt with a hammer.
That is, in the construction method using the shear bolt according to the prior art, the work on the slope and other concrete structures is complicated, and it cannot be said that the work safety is high.

Furthermore, the shear bolt according to the conventional art is manufactured by welding a member (a member corresponding to a petal) extending radially outward in the petal nut to the nut.
However, the work of welding a member extending outward in the radial direction (a member corresponding to a petal) to the nut is labor intensive. Moreover, in the shear bolt which functions as a structural member, it is desirable not to use a member that requires welding.

Japanese Patent No. 2858082 Japanese Patent No. 3695544

  The present invention has been proposed in view of the above-described problems of the prior art, and can be attached to an existing concrete layer by using an electric tool, thereby reducing work time and reducing work labor.・ The purpose is to provide reinforcement bolts (shear bolts) and repair and reinforcement methods using them.

  The repair / reinforcement bolt (3: shear bolt) of the present invention is divided into a plurality of parts (for example, two upper and lower parts) and a through hole is formed inside (4: slide collar) and a nut ( 5: long nut), a washer (6: petal washer) having a portion extending radially outward and a portion not extending, and an upper region of the nut (5: long nut) through the washer (6) A first bolt (7: upper bolt) to be screwed into the female screw (51) and a female screw (52) below the nut (5: long nut) through the cylindrical portion (4: slide collar) It has the 2nd volt | bolt (8: lower side volt | bolt) screwed together.

  In the present invention, the axial dimension of the nut (5: long nut) is the thickness of the layer (2: new spray layer) sprayed on the layer (1: existing concrete layer) in which the cylindrical portion (4: slide collar) is embedded. It is preferably 30 to 70% of the size.

  In the present invention, the cylindrical portion (4: slide color) is divided into two portions (41) and (42) by a boundary surface inclined with respect to the central axis of the cylindrical portion (4: slide color). Is preferred.

  Furthermore, it is preferable to have the 2nd washer (9: For example, a double washer: a single washer may be interposed) interposed between the nut (5: long nut) and the cylindrical part (4). However, the second washer (9) can be omitted.

The repair / reinforcement method of the present invention uses the above-described repair / reinforcement bolt (3: shear bolt),
Drilling an insertion hole (10) in a layer (1: existing concrete layer) in which the cylindrical portion (4) of the repair / reinforcement bolt (3) is to be embedded;
Inserting the cylindrical portion (4) side of the repair / reinforcement bolt (3) into the drilled insertion hole (10);
Rotating the first bolt (7: upper bolt) with the electric tool (20);
It is characterized by having a step of spraying a spray material (which constitutes a new spray layer (2)).

Here, the step of rotating with the power tool (20),
Screwing the male screw (71) of the first bolt (7: upper bolt) and the female screw (51: upper female screw) in the upper region of the nut (5: long nut);
Screwing the male screw (81) of the second bolt (8: lower bolt) and the female screw (52: lower female screw) in the lower region of the nut (5);
A step of compressing the cylindrical portion (4: slide collar) in the axial direction by the bolt head (82) of the nut (5) and the second bolt (8) and moving radially outward;
Sandwiching a washer (6: petal washer) having a portion extending radially outward and a portion not extending between the bolt head (72) of the first bolt (7) and the upper end of the nut (5);
It is preferable to have.

The repair / reinforcement method of the present invention is a method for determining a repair or reinforcement method when the mortar sprayed on the slope is aged,
The natural ground is stable (S1 is YES: sprayed on the slope), but the mortar is not in close contact with the natural ground (S2 is NO), and the amount of spring water is small (S3 is NO: remarkable due to spring water) If the adhesion between the mortar and the natural ground can be improved (S4 is YES), if the natural ground surface needs to be reinforced (S5 is YES), the back reinforcement (S7: void injection or Cavity filling) and surface reinforcement (S8)
If it is not necessary to reinforce the ground surface (S5 is NO), the combination of the back reinforcement (S11: void filling or cavity filling) and surface repair (S12: surface coating or crack repair), and the surface Select one of the reinforcement works (S14) that is more advantageous (matches the situation on site or is advantageous in terms of cost),
The surface reinforcing work (S14) is preferably used in combination with a method including a fiber reinforced mortar spraying work and a reinforcing reinforcing bar work.

According to the present invention having the above-described configuration, since the nut (long nut: 5) exists, the bolt head (72) of the first bolt (upper bolt: 7) is rotated by the electric tool (20). Then, the first bolt (7) that penetrates the washer (petal washer: 6) and the nut (5) upper region are screwed together, and the second bolt that penetrates the cylindrical portion (slide collar: 4) (Lower bolt: 8) and the nut (5) The lower end of the first bolt (7) penetrating the washer (6) and the cylindrical portion (4) even if screwed with the lower region The washer (6) is not in contact with the upper end of the second bolt (8), and the washer (6) passes through the bolt head (72) of the first bolt (7) and the upper end of the nut (5). Firmly sandwiched by Therefore, if the bolt head (72) of the first bolt (7) is rotated by the electric power tool (20), the washer (6) is reliably positioned at the upper end of the nut (5).
Therefore, if the length of the nut (5) (the vertical position of the upper end portion of the long nut 5 when tightened with the electric power tool 20) is set so that the washer (6) has a desired vertical position. The washer (6) is securely and accurately held at the vertical position (desired vertical position) of the upper end of the nut (5).
For this reason, the bolt head (72) of the first bolt (7) is rotated with the electric tool (20) while the washer (6) is at a desired vertical position, so that the repair / reinforcement bolt ( 3: Shear bolt) can be tightened at once.

According to the present invention, when the bolt head (72) of the first bolt (7) is rotated by the electric tool (20), the male screw (71) of the first bolt (7) and the nut (5). And a female screw (81) of the second bolt (8) and a female screw (52: lower female screw) of the nut (5). Screw together.
As a result, the second bolt (8) that penetrates the cylindrical portion (4) and the lower region of the nut (5) are firmly screwed together, and the second bolt (8) that penetrates the cylindrical portion (4). ) Are compressed and the parts (41, 42) constituting the cylindrical part (4) move radially outward (increase in diameter in the radial direction), so that the repair / reinforcement bolt (3) according to the present invention is securely attached. It can be fixed to the existing concrete layer (1).

Further, when the first bolt (7) penetrating the washer (6) and the upper region of the nut (5) are firmly screwed together, the washer (6) becomes the upper end of the nut (5). In a state of being in contact with this position (in a state of being sandwiched between the bolt head 72 of the first bolt and the upper end of the nut 5). Therefore, even if, for example, the lifeline and / or the operator's foot hanging on the lifeline hits the washer (6) before the spraying, the washer (6) is rotated for repair and reinforcement. The bolt (3) is prevented from coming off.
Therefore, it is not necessary for the operator to hit the upper end of the shear bolt with a hammer to crush the screw thread at the work site, and the work effort is reduced by the amount of the work (crushing the screw thread). At the same time, safety in work is improved.

Furthermore, since the washer (6) is firmly sandwiched between the bolt head (72) of the first bolt (7) and the upper end of the nut (5), the mounting strength of the washer (6) is ensured.
According to the present invention, the washer (6) can be manufactured by processing a single metal plate such as press molding, and a member extending radially outward as in the prior art is a nut. There is no need to weld to.
Therefore, it is not necessary to perform a welding operation when manufacturing a member used for construction, and it is not necessary to use a member that requires welding in a shear bolt.

It is a front view which shows the state in which the shear bolt used by embodiment of this invention is used. FIG. 2 is an exploded view showing the shear bolt shown in FIG. It is explanatory drawing which assembles and shows the shear bolt of FIG. 2 in the state before construction. It is process drawing which shows the insertion hole drilling process of the repair and reinforcement construction method using the shear bolt shown in FIG.1, FIG.2, FIG.3. It is process drawing which shows the process of inserting a shear bolt into an insertion hole. It is process drawing which shows the state which the slide collar in the existing concrete layer expanded in the radial direction. FIG. 6 is a process diagram showing a process of tightening a bolt head of an upper bolt with an electric tool in the state shown in FIG. 5. It is process drawing which shows the state which tightened with an electric tool and the upper side bolt, the lower side bolt, and the long nut are screwing together. It is explanatory drawing which shows the direction of the force which acts on a lower side volt | bolt and a slide collar when it tightens with an electric tool. It is process drawing which shows the state which the slide collar diameter-expanded by the existing concrete layer by radial direction by fastening with an electric tool. It is process drawing which shows the process of performing a spraying operation | work after a shear bolt is fixed to the existing concrete layer. It is a top view of a petal washer. It is AA arrow sectional drawing of FIG. It is a block diagram of a construction method selection system used in combination with an embodiment of the present invention. It is a flowchart which shows the control in the construction method selection system of FIG. It is the same flowchart as FIG. It is explanatory drawing which shows collapse of the spraying mortar which should be considered with the flowchart of FIG. It is explanatory drawing which shows the state which the spraying mortar which should be considered with the flowchart of FIG. 16 deteriorated. It is explanatory drawing of weathering of the natural ground which should be considered with the flowchart of FIG. It is explanatory drawing which shows collapse of the natural ground earth and sand which should be considered with the flowchart of FIG. It is explanatory drawing of the fall of the falling rock type which should be considered with the flowchart of FIG. 17 is a flowchart similar to FIGS. 15 and 16. FIG. 23 is a flowchart similar to FIG. 15, FIG. 16, and FIG. It is explanatory drawing which shows the 1st construction example suitably implemented by step S8 of FIG. 15, step S14, step SB15 of FIG. 16, step SC11 of FIG. 22, and step SC15. It is process drawing of the 1st construction example. It is a top view which shows the modification of a petal washer.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
In FIG. 1, a shear bolt 3 indicated as a whole by reference numeral 3 is fixed to an existing concrete layer 1 and embedded in a new spray layer 2.
As shown in FIGS. 1 and 2, the shear bolt 3 (repair / reinforcement bolt) has a slide collar 4, a long nut 5, a petal washer 6, an upper bolt 7, a lower bolt 8, and a second washer 9. doing.
The petal washer 6 has a part extending outward in the radial direction and a part not extending, and is a part manufactured by press molding from a sheet metal or the like.

The entire slide collar 4 has a cylindrical shape, and is divided into two parts 41 and 42 by a boundary surface 43 inclined with respect to the longitudinal central axis. A through hole is formed inside the slide collar 4.
In FIG. 1, the slide collar 4 is tightened in the axial direction (vertical direction in FIG. 1) and receives an axial compression force, and the portions 41 and 42 move (slide) along the boundary surface 43 by the compression force. The state in which the diameter is expanded in the radial direction (left-right direction in FIG. 1) is shown.
The state before the axial compression force is applied to the slide collar 4, that is, the state before the slide collar 4 is radially expanded is shown in FIGS.

The inner diameter of the through hole inside the slide collar 4 is larger than the outer diameter of the lower bolt 8. When the slide collar 4 is tightened and receives the compressive force in the axial direction, even if the two portions 41 and 42 move (slide) with each other along the boundary surface 43, they do not interfere with the lower bolt 8, and the required radial direction This is to ensure that the diameter can be expanded.
In other words, the inner diameter of the inner through hole of the slide collar 4 is the portion when the slide collar 4 slides along the boundary surface 43 due to the axial compression force acting on the outer diameter of the lower bolt 8. 41 and 42 are set large enough not to interfere with the lower bolt 8.

The upper bolt 7 passes through the petal washer 6, and the male screw 71 of the upper bolt 7 is screwed into a female screw 51 formed in the upper region of the long nut 5.
The petal washer 6 is sandwiched between the upper bolt 7 and the long nut 5 by tightening the bolt head 72 of the upper bolt 7 by interposing the petal washer 6 between the bolt head 72 of the upper bolt 7 and the long nut 5. Accordingly, the petal washer 6 is firmly held at the position of the upper end portion of the long nut 5.

In FIG. 1, the bolt head 82 of the lower bolt 8 is located in the lower part of the drawing.
A washer 9 (second washer) is interposed between the long nut 5 and the slide collar 4. Although not shown, the washer 9 can be omitted.
The washer 9 includes an upper washer 91 and a lower washer 92, and is a so-called “double washer”. However, the washer 9 can be configured as a single washer without being a double washer (not shown).

The lower bolt 8 passes through the slide collar 4 and the second washer 9, and the male screw 81 of the lower bolt 8 is screwed into a female screw 52 formed in the lower region of the long nut 5. .
When the slide collar 4 and the second washer 9 are sandwiched between the bolt head 82 and the long nut 5 of the lower bolt 8 and the bolt head 82 is tightened, the male screw 81 of the lower bolt 8 is placed in the lower region of the long nut 5. Since it is screwed into the formed female screw 52, the slide collar 4 is compressed in the vertical direction (longitudinal direction of the slide collar 4) in FIG. Is securely fixed to the existing concrete layer 1.

As shown in FIG. 1, the length of the long nut 5 (axial dimension: vertical dimension in FIG. 1) is such that the upper bolt 7 and the upper region of the long nut 5 are completely screwed together, and the lower bolt 8 and the length are long. When the lower region of the nut 5 is completely screwed, the lower end of the upper bolt 7 and the upper end of the lower bolt 8 are set so as not to contact each other.
At the same time, the length of the long nut 5 (axial dimension: vertical dimension in FIG. 1) is such that the upper bolt 7 and the upper region of the long nut 5 are completely screwed together, and the lower bolt 8 and the lower nut 5 lower side. When the petal washer 6 is sandwiched between the upper bolt 7 and the long nut 5 and is firmly held at the position of the upper end of the long nut 5, the petal washer is removed from the existing concrete layer 1. The distance up to 6 is set to be a predetermined distance.
Here, the predetermined distance from the existing concrete layer 1 to the petal washer 6 is set in a range of 30 to 70% of the thickness dimension of the new spray layer 2 sprayed to the existing concrete layer 1.

Details of the petal washer 6 are shown in FIGS. The petal washer 6 has a portion 61 that extends radially outward in the radial direction and a portion 62 that does not extend radially outward and forms a central portion. For example, it is manufactured by processing a single metal plate such as press molding.
In the illustrated embodiment, the portion 61 extending outward in the radial direction has a mountain-shaped cross section perpendicular to the center line extending radially (see FIG. 13), and thus its strength. Has improved. However, the cross-sectional shape can be flat.
The petal washer 6 is not limited to the shape shown in FIGS. For example, it is also possible to use a generally round petal washer 6 as shown in FIG.

The lower half of the shear bolt 3 (below the slide collar 4 and the lower bolt 8) is embedded in the existing concrete layer 1, and the upper half (the petal washer 6, the upper bolt 7, the long nut 5, the washer 9). The upper part of the lower bolt 8) is embedded in the new spray layer 2.
In the portion where the shear bolt 3 is embedded in the existing concrete layer 1 (lower half: the lower portion of the slide collar 4 and the lower bolt 8), the slide collar 4 is radially expanded as described above. The bolt 3 is firmly fixed to the existing concrete layer 1.

On the other hand, in the part (upper half: petal washer 6, upper bolt 7, long nut 5, washer 9, upper part of lower bolt 8) where the shear bolt 3 is embedded in the new spray layer 2, the petal washer 6 The shear bolt 3 is fixed to the new spray layer 2. In other words, the petal washer 6 exhibits the function of fixing the shear bolt 3 to the new spray layer 2.
Therefore, the vertical position (the upper end position of the long nut 5) of the petal washer 6 is appropriately set depending on the thickness of the new spray layer 2. And the vertical direction position (height position from the existing concrete layer 1 surface) of the petal washer 6 is within the range of 30 to 70% of the thickness of the new spray layer 2 from the surface of the existing concrete layer 1 as described above. Preferably there is.
When the position of the petal washer 6 is too close to the surface of the existing concrete layer 1 (when the distance from the existing concrete surface 1 is less than 30% of the thickness of the new spray layer 2), the position of the petal washer 6 is the position of the existing concrete layer 1 When it is too far from the surface (when the distance from the existing concrete surface 1 is larger than 70% of the thickness of the new spray layer 2), the shear bolt 3 is fixed to the new spray layer 2 by the petal washer 6 It has been confirmed by the inventor's experiment that this is not exhibited.

As described above, the petal washer 6 is firmly sandwiched between the bolt head 72 of the bolt (upper bolt 7) penetrating the petal washer 6 and the upper end portion of the long nut 5, so that the petal washer 6 is attached. Strength is secured.
In addition, in the illustrated embodiment, the petal washer 6 is manufactured by processing a single metal plate by press molding or the like, and does not have a welded portion. Since the welded portion is inferior in strength, the petal washer 6 used in the illustrated embodiment is compared with a petal nut (nut used in the prior art) in which a petal (portion extending radially outward) is welded to the nut. And its strength is high.

In FIG. 1 and FIG. 2, the shape of the bolt head 72 of the upper bolt 7 that penetrates the petal washer 6 is a normal hexagon, but other than the hexagon according to the configuration of the socket part of the power tool and other conditions. It can be shaped. For example, the shape of the bolt head 72 of the upper bolt 7 can be of a type in which the outer diameter is circular and a hole (so-called blind hole) that can be rotated with a hexagon wrench is formed in the center.
The cross-sectional shape of the long nut 5 is not limited to a hexagon. As long as the female screw is formed, there is no particular limitation on the cross-sectional shape of the long nut 5.

According to the embodiment described with reference to FIGS. 1 and 2, when the electric tool 20 is rotated and the upper bolt 7 is tightened, the upper bolt 7 is screwed with the upper region of the long nut 5 to tighten the petal washer 6. The side bolts 8 are screwed into the lower region of the long nut 5 to fasten the slide collar 4 and apply an axial compressive force, respectively. At that time, the lower end of the upper bolt 7 and the upper end of the lower bolt 8 do not come into contact with each other and do not interfere with each other.
The petal washer 6 is sandwiched between the bolt head 72 of the upper bolt 7 and the upper end portion of the long nut 5, and is firmly fixed to the position of the upper end portion of the long nut 5. Accordingly, the length of the long nut 5 (vertical position of the upper end of the long nut 5) is set so that the vertical position of the petal washer 6 becomes a desired position (the distance from the existing concrete layer becomes a predetermined distance). If set, the petal washer 6 has a desired vertical position corresponding to the thickness dimension of the new spray layer 2, and the effect of fixing the shear port 3 to the new spray layer 2 can be reliably achieved. .

At the same time, since an axial compressive force acts on the slide collar 4, the portions 41 and 42 move (slide) with each other along the boundary surface 43 and expand in the radial direction. 3 is firmly fixed to the existing concrete layer 1.
Thus, in the illustrated embodiment, the bolt head 72 of the upper bolt 7 can be rotated with the electric power tool 20 and fastened at once to fix the shear bolt 3, and the petal washer 6 is set to a desired vertical position, The shear bolt 3 can be fixed to the new spray layer 2.
Since the petal washer 6 is firmly clamped and fixed by the upper end of the long nut 5 and the bolt head 72 of the upper bolt 7, the petal washer 6 is rotated by touching the operator's foot when spraying. Is prevented.
Further, since the petal washer 6 can be manufactured by processing a single metal plate such as press forming, there is no need to weld a member extending radially outward to the nut, and the welding is inferior in strength. There is no need to provide a part.

Next, the repairing / reinforcing method of the shear bolt 3 described with reference to FIGS. 1 and 2 and the concrete structure using the same will be described with reference to FIG.
FIG. 4 is a process diagram showing an insertion hole drilling process of a concrete structure repair / reinforcement method using the shear bolt 3. In the process shown in FIG. 4, the lower half of the shear bolt 3 (the portion where the slide collar 4 is provided and the lower side thereof, specifically, the lower portion of the slide collar 4 and the lower bolt 8) is embedded in the existing concrete layer 1. An insertion hole 10 is drilled.

Here, the depth of the insertion hole 10 (axial dimension H in FIG. 4) does not need to be exactly equal to the dimension of the lower half of the shear bolt 3 (the place where the slide collar is provided and its lower side). As shown in FIG. 5, when the shear bolt 3 is inserted into the insertion hole 10, the lower washer 92 of the double washer 9 comes into contact with the surface 101 of the existing concrete layer 1, and the shear bolt 3 is further moved into the existing concrete layer. This is because it does not enter the insertion hole 10 drilled into 1.
The depth H of the insertion hole 10 is made equal to the dimension of the lower half of the shear bolt 3 (the place where the slide collar 4 is provided and its lower side), and the upper washer 91 and the lower washer 92 may be omitted. Is possible.
The inner diameter D of the insertion hole 10 is larger than the outer diameter of the shear bolt 3 before the slide collar 4 is expanded, and when the slide collar 4 is expanded during construction, it bites into the existing concrete layer 1 and is firmly fixed. Are set to dimensions.

FIG. 5 shows a process of inserting the shear bolt 3 into the insertion hole 10.
Prior to the step shown in FIG. 5, the shear bolt 3 is assembled as shown in FIG. In the state of FIG. 3, the upper bolt 7 passes through the petal washer 6, and the male screw 71 and the female screw (the upper female screw 51) of the long nut 5 are only partially screwed together. The lower bolt 8 passes through the slide collar 4, and only a part of the male screw 81 and the female screw (lower female screw 52) of the long nut 5 are screwed together. In the state shown in FIG. 3, the shear bolt 3 is not tightened in the axial direction, and the axial compression force does not act on the slide collar 4 and the diameter is not expanded.

In the process of FIG. 5, the lower half of the shear bolt 3 in the state shown in FIG. 3 (the lower part of the slide collar 4 and the lower bolt 8) is inserted into the insertion hole 10 drilled in the existing concrete layer 1.
The shear bolt 3 is inserted into the insertion hole 10 until the lower washer 92 of the double washer 9 contacts the surface 101 of the existing concrete layer 1. Here, when the lower washer 92 of the washer 9 comes into contact with the surface of the existing concrete layer 1, the shear bolt 3 is configured not to be inserted into the insertion hole 10 any more.

In the state of the process shown in FIG. 5, the male screw 71 of the upper bolt 7 and the female screw (upper female screw 51) of the long nut 5 are not completely screwed, and only a part is screwed. is there. The male screw 81 of the lower bolt 8 and the female screw (lower female screw 52) of the long nut 5 are not completely screwed, and only a part is screwed.
No axial compressive force is applied to the slide collar 4, and the portions 41, 42 are not slid along the boundary surface 43 and are not expanded in the radial direction. That is, the slide collar 4 has a cylindrical shape.

In the state of FIG. 5, by tightening the bolt head 72 of the upper bolt with the wrench part 21 (FIG. 7) of the electric tool 20 (FIG. 7), the shear bolt 3 in the existing concrete layer 1 is removed as shown in FIG. The slide collar 4 expands in the radial direction.
In FIG. 6, in the portion (lower half) where the shear bolt 3 is embedded in the existing concrete layer 1, the slide collar 4 is expanded in the radial direction, so that the lower half of the shear bolt 3 is the existing concrete. Firmly attached to layer 1.
Further, the petal washer 6 is firmly sandwiched between the bolt head 72 of the upper bolt 7 and the upper end portion of the long nut 5.

The details when the bolt head 72 of the upper bolt 7 of the shear bolt 3 (the bolt passing through the petal washer) is rotated by the electric power tool 20 will be described with reference to FIGS.
FIG. 7 is a process diagram showing a state in which the shear bolt 3 is tightened with the electric tool 20.
In FIG. 7, the wrench portion 21 of the electric power tool 20 is engaged with the bolt head 72 of the upper bolt 7 of the shear bolt 3 inserted into the insertion hole 10. Then, the electric power tool 20 is driven to rotate the bolt head 72, and the shear bolt 3 is tightened.

When the electric power tool 20 is driven and the bolt head 72 is rotated, as shown in FIG. 8, the male screw 71 of the upper bolt 7 and the female screw (the upper female screw 51) of the long nut 5 are completely screwed together. . At the same time, the male screw 81 of the lower bolt 8 penetrating the slide collar 4 and the female screw of the long nut 5 (lower female screw 52) are completely screwed together.
When the male screw 71 of the upper bolt 7 and the female screw (the upper female screw 51) of the long nut 5 are completely screwed together, the petal washer 6 is moved by the bolt head 72 of the upper bolt 7 and the upper end of the long nut 5. , Firmly sandwiched.
Here, since the long nut 5 exists in the illustrated embodiment, the upper bolt 7 and the upper region 51 of the long nut 5 are sufficiently screwed together, and the lower bolt 8 and the lower region 52 of the long nut 5 are connected. Even when fully screwed, the lower end of the upper bolt 7 and the upper end of the lower bolt 8 do not contact each other, and a gap δ exists in the long nut 5.

When the rotational force of the electric tool 20 is further applied to the upper bolt 7 in the state shown in FIG. 8, as shown in FIG. 9, the long nut 5 and the lower bolt 8 that are sufficiently screwed with the lower bolt 8 are connected. The bolt head 82 applies the axial compression force F of the lower bolt 8 to the slide collar 4. Therefore, the two portions 41 and 42 of the slide collar 4 move (slide) with each other at the boundary surface 43, and move in the left-right direction (radially outward) in FIG. That is, the diameter is increased in the radial direction.
More specifically, in FIG. 9, the two portions 41 and 42 of the slide collar 4 to which the axial compression force F is applied receive a horizontal component (pressing force) F _h of the shearing force that acts on the boundary surface 43. . By the pressing force F _h, 2 two parts 41 and 42 of the slide collar 4 expanded radially outward by overcoming the frictional resistance or various resistances slides to one another at the interface 43. As a result, the slide collar 4 firmly presses the existing concrete layer 1 or bites into the existing concrete layer 1 (see FIG. 6), so that the shear bolt 3 is firmly attached to the existing concrete layer 1.

With reference to FIG. 10, a state where the slide collar 4 is expanded in the radial direction will be described.
FIG. 10 shows a final state in which the two portions 41 and 42 of the slide collar 4 are slid relative to each other at the boundary surface 43 and expanded in the radial direction.
In FIG. 10, the reference symbol t1 is the nominal length of the upper bolt 7 (the length under the neck), and the symbol t2 is the nominal length of the lower bolt 8 (the length under the neck, from the lower end of the bolt head 72 of the upper bolt 7). The length L of the lower bolt 8 to the lower end of the bolt head 82 is
L = t1 + t2 + δ
Here, δ is a gap between the lower end of the upper bolt 7 and the upper end of the lower bolt 8 generated in the long nut 5 as described above. By setting δ> 0, the shear bolt 3 is maximized. Even when the upper bolt 7 and the upper region of the long nut 5 are sufficiently screwed together and the lower bolt 8 and the lower region of the long nut 5 are sufficiently screwed together, It does not contact the upper end of the lower bolt 8 and does not interfere with it.

  In the state shown in FIG. 10, the petal washer 6 is firmly sandwiched between the bolt head 72 of the upper bolt 7 and the upper end of the long nut 5, and therefore does not move in the axial direction (vertical direction) from the position of the upper end of the long nut 5. . Therefore, the upper bolt 7, the upper region of the long nut 5, the lower bolt 8, and the long nut with the petal washer 6 held in a predetermined position (the upper end portion of the long nut 5) in the axial direction of the shear bolt 3. 5 can be tightened at a stretch by screwing the male and female screws into the lower region.

After tightening the bolt head 72 of the upper bolt 7 with an electric tool (FIGS. 6 to 10), a spraying operation is performed as shown in FIG.
As described above, the axial position of the petal washer 6 fixed in this way is determined in accordance with the thickness dimension of the new spray layer), and is 30 to 70% of the thickness of the new spray layer 2.
As shown in FIG. 11, the spray material 31 is sprayed on the existing concrete layer 1 from the nozzle 30 of a spray machine (not shown) until it becomes a predetermined thickness dimension, and the new spray layer 2 is formed.

According to the illustrated embodiment, in the step of rotating the upper bolt 7 with the electric tool 20, as described with reference to FIGS.
A step of screwing the male screw 71 of the upper bolt 7 and the female screw 51 in the upper region of the long nut 5;
Screwing the male screw 81 of the lower bolt 8 and the female screw 52 in the lower region of the long nut 5;
A step of compressing the slide collar 4 in the axial direction by the long nut 5 and the bolt head 82 of the lower bolt 8 to expand the diameter in the radial direction;
Retightening the male screw 71 of the upper bolt 7 and the female screw 51 in the upper region of the long nut 5 and retightening the male screw 81 of the lower bolt 8 and the female screw 52 in the lower region of the long nut 5;
A step of firmly sandwiching the petal washer 6 between the bolt head 72 of the upper bolt 7 and the upper end of the long nut 5;
These five steps are included.
Thereby, the shear bolt 3 is firmly fixed to the existing concrete layer 1, and the petal washer 6 is firmly fixed to a predetermined position (position of the upper end of the long bolt 5).

The repair / reinforcement performed by burying the shear bolt described with reference to FIGS. 1 to 13 is performed at appropriate intervals in the specified target area. This repair / reinforcement is performed, for example, when “the surface reinforcement work should be performed” is selected by the system that implements the method selection method shown in FIG. In this surface reinforcement work, construction (fiber-reinforced mortar spraying or surface reinforcement (thickening) work) for increasing the thickness of the mortar layer by further spraying mortar on the surface of the existing mortar spraying is performed.
In FIG. 14, the construction method selection system generally indicated by reference numeral 60 includes a cost calculation device 61, a construction method selection device 62, and a storage device 63.

The cost calculation device 61 is connected to the input device (for example, a keyboard) 7 via a line L71, connected to the construction method selection device 62 via a line L12, connected to the storage device 63 via a bidirectional line L13, and the display device 8 Connected by line L18.
And the cost calculation apparatus 61 will calculate the cost of several construction methods from the construction method data output from the memory | storage device 63, if the matter (data) required for cost calculation is input by the input device 7. FIG. Then, the calculation result is output to the construction method selection device 62, the storage device 63 and the display device 8.

The construction method selection device 62 is connected to an input device (for example, a keyboard) 7 via a line L72. Does the construction method selection device 62 to the input method 7 match the construction site conditions and the construction conditions of the target construction method? Various information and data related to whether or not are entered.
The construction method selection device 62 is connected to the storage device 63 via a line L32, and is connected to the display device 8 via a line L28.
When items necessary for cost calculation are input by the input device 7, the construction method selection device 62 outputs construction method data output from the storage device 63 (data on whether or not it matches the situation of the construction site), With reference to a plurality of cost calculation results output from the cost calculation device 61, a construction method that matches the situation of the construction site and / or has a low cost is selected, and the selected construction method is displayed on the display device 8. Output.

The input device 7 is connected to the storage means 63 via a line L73, and is connected to the display device 8 via a line L78.
When the construction method selection system 60 is activated, for example, questions such as steps S1 to S5 in the flowchart shown in FIG.
Then, an operator (operator) who operates the construction method selection system 60 answers the question by the input device 7.

Next, control of construction method selection by the construction method selection apparatus 100 of FIG. 14 will be described with reference to FIGS.
In the method selection control shown in FIGS. 15, 16, 22, and 23, as described above, the system operator (not shown) of the system 100 is displayed on the monitor 8 of the display device (reference numeral 8 in FIG. 14). Various questions are displayed. Then, the system operator answers the question with, for example, “YES”, “NO”, or the like using the keyboard 7 which is an input device.
Alternatively, a system operator (not shown) can use the keyboard 7 as an input device to obtain information (data) necessary for cost calculation, various information related to whether the construction site conditions match the construction conditions of the target construction method, Data is entered.
Here, instead of using the construction method selection device 100, a site worker can perform construction method selection. In other words, the construction method selection can be controlled not by the construction method selection apparatus 100 but by a field worker.

In step S <b> 1 of FIG. 15, a question “Is the back ground mountain stable?” Is displayed on the monitor 8 of the display device 8. In step S1, when the back ground is stable (over soft rock) (step S2 is YES), the system operator or the investigator (operator) inputs “YES” with the input device 7.
Then, it progresses to step S2 and the question "Is the mortar on the slope surface closely attached to the natural ground?" Is displayed on the monitor 8 of the display device 8.

In step S2, when the mortar on the slope surface is not in close contact with the natural ground (step S2 is NO), the operator inputs “NO” with the input device 7.
When the operator inputs “NO”, a question “Is there a remarkable deformation due to spring water?” Is displayed on the monitor 8 of the display device 8 in step S3.

When there is no remarkable deformation due to spring water (NO in step S3), the operator inputs “NO” in step S3.
In step S 4, a question “Can you improve the adhesion?” Is displayed on the monitor 8 of the display device 8.

In step S <b> 4, if the adhesion can be improved (YES in step S <b> 4), the operator inputs “YES” with the input device 7.
In step S5, a question “Is it necessary to reinforce the ground surface?” Is displayed on the monitor 8 of the display device 8.

In step S5, when it is necessary to reinforce the natural ground surface layer (step S5 is YES), the operator inputs “YES” by the input device 7 d, and in step S6, the thickness of the back ground natural soil layer becomes 0. After confirming that the distance is 5 m or less, the process proceeds to step S7.
If it is not necessary to reinforce the ground surface in step S5 (NO in step S5), the process proceeds to step S9.

In step S <b> 7, a message that “rear surface reinforcement work should be performed” is displayed. In the case of the back side construction method, void filling work (injecting cement or the like into the void created in the lower part of the surface mortar spraying) or cavity filling work (cement in the cavity larger than the void created in the lower part of the surface mortar spraying) Etc.) is constructed.
Proceeding from step S7 to step S8, "Surface reinforcement work should be performed" is displayed. In the surface reinforcement work, mortar is further sprayed on the surface of the existing mortar spraying to increase the thickness of the mortar layer (fiber reinforced mortar spraying or surface reinforcement (thickening) work). The mortar used in that case is a fiber reinforced mortar in which reinforcing fibers are mixed with cement (see FIG. 24).
In addition to that, a reinforcing bar is constructed in step S8. That is, in step S8, fiber reinforced mortar spraying and reinforcing bar work are performed.
Here, the length (for example, 1 m) of the reinforcing bar in the reinforcing bar is determined on a case-by-case basis depending on the thickness of the unstable layer.

  In the case of step S9 (step S5 is NO), it is determined that “the back ground is stable to a soft rock level”, and then the process proceeds to step S10. In step S10, either the construction method combining the back reinforcement work and the surface repair work ("A construction method" in step S10 of FIG. 15) or the surface reinforcement construction ("B construction method" in step S10 of FIG. 15) is the construction site. To determine whether it is advantageous. Here, the term “advantageous” means that it conforms to the conditions of the construction site and / or is advantageous in terms of cost. And in order to judge whether it is advantageous in terms of cost, the cost calculation device 61 of the construction method selection system 60 calculates the costs of both the A method and the B method, and either A or B method is cost effective. Determine if it is advantageous.

  If it is determined that “A method (a method in which the back surface reinforcement work and the surface repair work are combined) is more advantageous”, the process proceeds to step S11. In step S <b> 11, a message that “rear surface reinforcement work should be performed” is displayed. In the back reinforcement work, void filling work (construction injecting cement etc. into the void created in the lower part of the surface mortar spraying), or cavity filling work (cementing in the cavity larger than the void created in the lower part of the surface mortar spraying) Etc.) is performed. Then, the process proceeds to step S12, and a message that “surface repair work should be performed” is displayed. The surface repair work is a surface repair work (coating work) and / or a crack repair work.

On the other hand, if it is determined that “the B method (surface reinforcing method) is more advantageous”, the process proceeds to step S14, and “Surface reinforcing method should be performed” is displayed as in step 8 described above.
Here, the cost of spraying the fiber reinforced mortar in the surface reinforcing work can be easily calculated from the area of the construction site and the length of the bottom side.

  In step S2, when the mortar on the slope surface is in close contact with the natural ground (step S2 is YES), when the operator inputs “YES” with the input device 7, the control is performed in step “ Go to “B”.

  In the control of FIG. 16, in step SB1, the monitor 8 of the display device 8 asks "Is there a possibility that the mortar piece may be peeled off (see FIG. 18) or collapsed (see FIG. 17) due to surface deterioration such as cracks?" A question is displayed. In step SB1, if there is a possibility that the mortar pieces may be peeled off or collapsed due to surface deterioration such as cracks (step SB1 is YES), the operator inputs “YES” using the input device 7.

  Here, the peeling of the mortar piece is a phenomenon in which the mortar piece 203d sprayed on the slope of the natural ground 200 falls downward as shown in FIG. Moreover, the collapse of the mortar sprayed on the slope is a phenomenon in which a partial region 203D of the mortar sprayed on the slope of the natural ground 200 collapses as shown in FIG.

  When there is a possibility that the mortar piece may be peeled off or collapsed (step SB1 is YES), a crack opening is recognized in a wide range (step SB2). And it progresses to step SB3 and it is judged which method of surface repair work and surface reinforcement work is advantageous. Similar to step S10 (FIG. 15), the term “advantageous” means that it meets the conditions of the construction site and / or is advantageous in terms of cost. Then, in order to determine whether it is advantageous in terms of cost, the cost calculation device 61 of the method selection system 60 calculates the cost of either surface repair work or surface reinforcement work.

If surface repair work is more advantageous (“surface repair work is more advantageous” in step SB3), surface repair work (specifically, a coating work for coating the surface with new mortar) is performed in step SB4. A message to the effect is displayed.
On the other hand, if surface reinforcement is more advantageous (“surface reinforcement is more advantageous” in step SB3), “surface reinforcement (specifically, fiber reinforced mortar is sprayed on the surface to surface mortar) “A method of increasing the thickness of the layer and embedding a reinforcing bar having a length of 1 m at a right angle to the slope surface” is displayed.

  In step SB1, when there is no possibility of the mortar piece peeling or collapsing due to surface deterioration such as cracking (step SB1 is NO), the operator inputs “NO” with the input device 7. And (when there is no possibility of peeling or collapsing of the mortar pieces due to surface deterioration such as cracks: Step SB1 is NO), it is determined that there is no particular problem even if repair is not performed, and the process proceeds to Step SB6. “Monitoring (no countermeasures)” is displayed on the monitor 8.

Here, in step S1 of FIG. 15, “whether or not the back ground mountain is stable” is determined in addition to the determination of whether or not the mortar itself has deteriorated due to cracks or floating on the mortar surface. The investigator visually confirms whether there is any collapse due to weathering of the mountain or slip due to earth pressure from the back. Alternatively, it is confirmed by a known investigation method.
The weathering of the back ground is caused by loosening of the groundwater or cracks due to freezing of the groundwater, and the slip due to earth pressure may be, for example, release of stress due to cut.

FIG. 19 shows a state (201) in which the natural ground 200 is weathered just below (inside) the spray mortar 203 on the surface.
The presence / absence of weathering and the thickness (W) survey of the weathered layer are determined by, for example, the amount of round steel penetration during the core removal survey.
FIG. 20 shows a state in which weathered earth and sand 201 collapses from the slope and falls together with the surface sprayed mortar 203D separated by the crack.
FIG. 21 shows that a crack occurred in the natural ground 200 and the fall of the falling rock 200D type occurred.

When the back ground is not stable in step S1 of FIG. 15 (step S1 is NO), the operator himself who received the report from the investigator inputs “NO” with the input device 7.
If the back ground is not stable (NO in step S1), the process proceeds to “C” in the control of FIG.

In step SC1 of FIG. 22, the question “Is there a possibility of a rock slide or a landslide?” Is displayed on the monitor 8 of the display device 8.
When it is determined that there is a possibility of a rock slide or a landslide based on the survey results of the field investigator (step SC1 is YES), “YES” is input by the input device 7. Then, the process proceeds to step SC <b> 2 and the monitor 8 displays that “the landslide countermeasure work should be taken” on the monitor 8 of the display device 8.

  Landslide countermeasure work is a restraint work that destroys a rockslip or a place where there is a possibility of a landslide (demolition work), and processes the generated soil (earth removal work) and / or drives an anchor (anchor work), It is a deterrent that drives a deterrent pile (deterrent pile).

If there is no possibility of a rock slide or landslide (NO in step SC1), “NO” is input by the input device 7. Then, in step SC3, a question “Is there a remarkable deformation due to spring water?” Is displayed on the monitor 8 of the display device 8.
If there is no significant deformation due to spring water (NO in step SC3), “NO” is input by the input device 7.
In step SC4, the construction method selection system 60 determines whether it is advantageous to demolish the existing mortar. Here, as described above, the term “advantageous” means that it conforms to the conditions of the construction site and / or is advantageous in terms of cost. And about a cost, a disadvantage is calculated by the cost calculation apparatus 61 of the construction method selection system 60. FIG.

If the demolition of the existing mortar is advantageous in terms of cost, the process automatically proceeds to step SC5, and the monitor 8 displays that “removal work (demolition work and industrial waste treatment) should be performed”.
Proceeding to step SC6, the monitor 8 displays that the “slope stabilization work” in which cutting work, mortar spraying, spraying frame work and rebar insertion work should be performed is performed.
On the other hand, if it is not advantageous to demolish the existing mortar (NO in step SC4), in step SC7, it is displayed on the display device 8 that the thickness of the unstable layer assumed as the back ground is selected. The operator selects the thickness of the unstable layer from “0.5 m or less”, “0.5 m to 3.0 m”, or “3.0 mm or more” by the input device 7.
From the inventors' experience, the collapse depth is very often 50 cm or less.
In addition, it is well known to those skilled in the art that in the case of slope collapse, those whose collapse depth is less than 3 m is about 80% of the total.
Steps SC9 to SC11, SC13 to SC15, and SC17 to SC19 in FIG. 22 are classified into three types based on such knowledge.

When the thickness of the unstable layer is “0.5 m or less”, the process proceeds to step SC8, and it is determined whether or not the cost from step SC9 to step SC11 falls within the determined range (budget frame).
In step SC8, if the total cost from step SC9 to step SC11 is within the determined budget frame (YES in step SC8), the monitor 8 indicates that “rear surface reinforcement work should be performed” in step SC9, Next, the process proceeds to step SC10, where the monitor 8 indicates that “a natural ground reinforcement work (a 2 m long reinforcing bar should be inserted at right angles to the slope)” is displayed on the monitor 8, and “fiber reinforced mortar spray (or surface) Reinforcement (thickening) work, spray method frame work and pressure plate work should be performed ”is displayed on the monitor 8.
Here, in the fiber reinforced mortar spraying, the fiber reinforced mortar is newly sprayed on the existing mortar spraying surface.
On the other hand, if the total cost from step SC9 to step SC11 does not fall within the determined budget frame (step SC8 is NO), the process returns to step SC4, and steps SC4 and after are repeated.

When the thickness of the unstable layer is “0.5 to 3.0 m”, it is determined in step SC12 whether or not the total cost from step SC13 to step SC15 is within a predetermined range (budget frame). to decide.
In step SC12, if the total cost from step SC13 to step SC15 is within the determined budget frame (YES in step SC12), the monitor 8 indicates that “rear surface reinforcement work should be performed” in step SC13, Next, the process proceeds to step SC14, and the monitor 8 displays that "a natural ground reinforcement work (inserting a reinforcing bar 2-5 m in length perpendicular to the slope)" is performed, and in step SC15, " The fact that “fiber reinforced mortar spraying, spraying frame work and pressure plate work” should be performed is displayed on the monitor 8.
On the other hand, if the total cost from step SC13 to step SC15 does not fall within the determined budget frame (NO in step SC12), the process returns to step SC4 and repeats the steps from step SC4.

When the thickness of the unstable layer is “3.0 m or more”, in step SC16, it is determined whether or not the total cost from step SC17 to step SC19 falls within a predetermined range (budget frame).
In step SC16, if the total cost from step SC17 to step SC19 is within the determined budget frame (YES in step SC16), the monitor 8 indicates that “rear surface reinforcement work should be performed” in step SC17. Is done. Then, the process proceeds to step SC18, and the monitor 8 displays that “the ground reinforcement work (anchor work) should be performed”.
Here, in steps SC8, SC12, and SC16, the determination regarding the total cost is performed, but it is possible to determine based on other criteria. Alternatively, steps SC8, SC12, and SC16 can be deleted.

Then, in step SC19, the message that “the spray method frame work and the pressure plate work should be performed” is displayed on the monitor 8.
On the other hand, if the total cost from step SC17 to step SC19 does not fall within the determined frame (step SC16 is NO), the process returns to step SC4 and repeats step SC4 and subsequent steps.

In step SC3, when there is a noticeable deformation due to spring water (YES in step SC3), [YES] is input by the input device 7.
In that case, the process proceeds to step “D” in the control of FIG.

In FIG. 23, in step SD <b> 1, a question “Is drainage work necessary?” Is displayed on the monitor 8 of the display device 8.
Here, when deciding whether or not drainage countermeasures are necessary, in addition to the situation at the construction site, consider whether the costs of drainage countermeasures and groundwater drainage work are within the specified value. To do.

When the drainage countermeasure work is necessary (YES in step SD1), the process returns to step SC4 in FIG. 22, and step SC4 and subsequent steps are repeated.
When the drainage countermeasure work is not required (NO in step SD1), the process proceeds to step SD2, and the message “removal work (demolition work and industrial waste treatment)” is displayed on the monitor 8 of the display device 8. Then, in step SD3, the display device 8 displays “to perform slope stabilization by mortar spraying”.

As described above, in FIG. 15, after determining whether or not the natural ground is stable, it is determined whether or not it is in close contact with the natural ground.
In the conventional technology, for example, the aging diagnosis technique of the spray slope by the conventional far-infrared imaging method, it is not determined whether or not the natural ground is stable. Therefore, in the conventional technology, when the mortar is not in close contact with the ground and the adhesiveness cannot be improved, in other words, the risk of the ground is not taken into account, or the risk of rock slide or landslide is considered. If not, there is a possibility of diagnosing the removal of aging mortar without taking such risks into account.
And it is unsuitable for disaster prevention to diagnose the removal of aging mortar without considering the danger in natural ground.

On the other hand, the illustrated embodiment is a technique for preventing slope collapse and is a disaster prevention measure. And control is performed on the premise that the most important element for disaster prevention measures is the stability of natural ground.
Therefore, in the embodiment shown in the figure, it is first determined whether or not the natural ground is stable, considering the danger of the natural ground, or judging that there is no rock slide or landslide, and has become aging Diagnose whether to remove the mortar.
Therefore, if the mortar is not in close contact with the ground and its adhesion cannot be improved, it will not be diagnosed that the old mortar will be removed. It is.

Further, as shown in FIG. 15, in the illustrated embodiment, it is determined whether or not the adhesion is improved after confirming that there is no remarkable deformation due to spring water.
When the amount of spring water is large, backfilling cannot be performed, and the adhesion of mortar to natural ground is not improved. In the method selection control shown in FIG. 15, since it is determined whether or not the amount of spring water is large before determining whether or not the adhesion can be improved, backfilling is performed even though the amount of spring water is large. Is prevented.

Furthermore, in the illustrated embodiment, since the construction cost is always calculated when selecting the construction method, there is little risk of selecting a construction method that is disadvantageous in terms of cost.
In addition, the cost in spraying can be easily calculated from the area of the construction site and the length of the bottom.

An example of construction (first construction example) performed in step S8, step S14 in FIG. 15, step SB5 in FIG. 16, step SC11 in FIG. 22, and step SC15 (first construction example) is referred to FIG. I will explain.
The construction includes a fiber reinforced mortar sprayer and a reinforcing steel bar.

In FIG. 24, first, the lifeline 80 is arranged from above the slope TF from below ("preparation work" SX1 in FIG. 25).
Here, on the slope TF of the construction site, there is a layer 201 that has become weathered and becomes unstable between the natural ground 200 and the existing concrete spray layer 202.
In FIG. 24, a cavity 204 (or a gap) also exists between the unstable layer 201 and the existing concrete spray layer 202.

In the “reinforcing bar” SX2 in FIG. 25, for example, an L-shaped reinforcing bar 90 having a length of 1 m is driven from the surface of the existing concrete spray layer 202 at a right angle to the slope TF.
Here, the head (L-shaped part) of the L-shaped reinforcing bar 90 driven into the slope TF is constructed so as to remain within the thickness of the mortar layer 203 to be sprayed.

In “back cavity injection” SX3 in FIG. 25, an injection hole is drilled in a part of the existing concrete spraying (surface) 202 located at the upper end of the cavity (gap) 204, and the injection material is injected through the hole. Is injected into the cavity 204. This back cavity injection work SX3 can be omitted when the thickness of the cavity 204 is less than the allowable amount.
When the “rear cavity injection work” SX3 is performed, an injection material feeder (not shown) is installed on the ground surface GF connected to the lower end of the slope TF. A spraying worker (not shown) holds a tip nozzle (not shown) of a spraying hose (not shown) of the injection material feeder (not shown), and the injection material is injected from the injection hole formed in the cavity 204. Is injected into the cavity 204.

  In “shear bolt construction” SX4 in FIG. 25, dedicated shear bolts 91 are embedded in several locations of the existing concrete spraying surface 202 in the vicinity where the cavity 204 is formed on the back surface by a known construction method.

  In the “new drainage pipe construction” SX5 in FIG. 25, the drainage pipe 92 is placed in a horizontal state at the position corresponding to the lower end of the cavity 204 of the existing concrete spray (surface) 202 with its tip slightly facing downward. Buried with.

In “Slope cleaning worker” SX6 in FIG. 25, the equipment used in the above SX1 to SX5 and the waste soil generated by each method are removed from the slope, and the slope is cleaned by watering the slope.
And "fiber reinforcement mortar spraying work" SX7 is constructed.

The state which is constructing the fiber reinforced mortar sprayer SX7 is shown in FIG.
In the example of FIG. 24, a wet sprayer 10A is installed on the ground surface GF connected to the lower end of the slope TF. Mortar material).
A spray hose 17A to which a nozzle 50A is attached is connected to the wet sprayer 10A, and the spray worker M holds the tip nozzle 50A and moves to the vicinity of the construction area.

The spray worker M is tied with a lifeline 80 and is positioned on the slope TF in a safe state.
Then, cement milk mixed with a fiber reinforcing material is sprayed onto the slope TF from the nozzle 50A toward the lower end of the construction area.
When the fiber reinforced mortar spraying work SX7 is completed, the worker M removes the lifeline 80 from the slope and returns to the ground surface GF from the slope together with the spray hose 17A.

  Here, in the illustrated embodiment, the method selection control is performed by the method selection device 100, but a site worker can execute the method selection. That is, the construction method selection in the illustrated embodiment may be performed by a field worker.

  It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Existing concrete layer 2 ... New spray layer 3 ... Shear bolt (bolt for repair and reinforcement)
4 ... Slide color (cylindrical part)
5. Long nut (nut)
6 ... Petal washer (washer)
7 ... Upper bolt (first bolt)
8 ... Lower bolt (second bolt)
9 ... Double washer (second washer)
DESCRIPTION OF SYMBOLS 10 ... Insertion hole 20 ... Electric power tool 21 ... Wrench part 30 ... Spray nozzle

Claims (6)

  A cylindrical part that is divided into a plurality of parts and has a through hole formed therein, a nut, a washer having a part extending radially outward and a part not extending, and an upper region of the nut through the washer A repair / reinforcement bolt comprising: a first bolt that is screwed into the female screw; and a second bolt that passes through the cylindrical portion and is screwed into the female screw in the lower region of the nut.   The repair / reinforcement bolt according to claim 1, wherein an axial dimension of the nut is 30 to 70% of a thickness of a layer sprayed on a layer in which the cylindrical portion is embedded.   The repair / reinforcement bolt according to claim 1, wherein the cylindrical portion is divided into two parts by a boundary surface inclined with respect to the central axis of the cylindrical portion.   The bolt for repair and reinforcement according to any one of claims 1 to 3, further comprising a second washer interposed between the nut and the cylindrical portion. In the repair / reinforcement method using the repair / reinforcement bolt according to any one of claims 1 to 4,
Drilling an insertion hole in the layer in which the cylindrical portion of the repair / reinforcement bolt is to be embedded;
Inserting the cylindrical part side of the repair / reinforcement bolt into the drilled insertion hole;
Rotating the first bolt with an electric tool;
A repair / reinforcement method characterized by having a step of spraying a spray material. The step of rotating with the electric tool includes:
Screwing the male screw of the first bolt and the female screw in the upper region of the nut;
Screwing the male screw of the second bolt and the female screw in the lower region of the nut;
Compressing the cylindrical portion in the axial direction by the bolt head of the nut and the second bolt and moving the cylindrical portion outward in the radial direction;
A step of sandwiching a washer having a portion extending radially outward and a portion not extending between the bolt head of the first bolt and the upper end of the nut;
The repair / reinforcement method according to claim 5.

Images