JP6933520B2 - Reinforcement anchor - Google Patents

Description

The present invention relates to, for example, a reinforcing anchor used in a shaft wall for shield excavation.

Conventionally, as a shaft excavation shaft wall used when constructing an underground tunnel or a sewage main by a shield method, as shown in Patent Documents 1 and 2, for example, a composite in which a hard urethane resin is reinforced with long glass fibers. A cutting wall made of material and composed of members that can be cut by a shield excavator cutter is used.
However, when the outer diameter of the shield is large or the depth of the ground at the starting point is deep, the soil water pressure applied to the cutting wall from the ground around the shaft increases and the deflection of the cutting wall inside the shaft increases. Construction becomes difficult. Therefore, it is conceivable to suppress the above-mentioned deflection by increasing the wall thickness of the cutting wall to increase the strength, but the wall thickness of the entire shaft becomes large, resulting in a structure with low economic efficiency.

Therefore, it is possible to reduce the deflection of the cutting wall by reinforcing the cutting wall by using a machinable anchor or a cutting beam, a removable anchor that can be removed before cutting, or the like. Further, by keeping the wall thickness of the cutting wall small, it is possible to apply it even under the condition that the outer diameter of the shield is large and the depth is deep, and a shaft wall for shield excavation with reduced cost is adopted.

Japanese Unexamined Patent Publication No. 8-303178 Japanese Unexamined Patent Publication No. 9-013875

However, when the conventional cutting wall as described above is reinforced with an anchor, when the excavation by the shield excavator progresses and the anchor is cut by the cutter, the anchor force disappears and the pressure receiving plate transmits the anchor force to the cutting wall. Can no longer be restrained. Therefore, the reaction force required to cut the pressure receiving plate cannot be obtained, and the uncut pressure receiving plate falls into the chamber near the cutter of the shield excavator, causing blockage in the chamber and delaying the construction period. There was a problem.

Therefore, the present invention has been made in view of the above problems, and it is possible to suppress an increase in the cost of the shaft, prevent blockage in the chamber of the shield excavator, and suppress a delay in the construction period. It is intended to provide a reinforcing anchor.

In order to achieve the above object, the reinforcing anchor according to the present invention penetrates a cutting wall that can be cut by a shield excavator and is fixed to the ground in a state where a predetermined tensile force is applied, and can be cut by the shield excavator. A reinforcing anchor, one end side in the tension axis direction is fixed to the ground by a fixing material, and the other end side protrudes from the cutting wall and fits into a tension material having a threaded portion on an outer peripheral surface and the outside of the tension material. The pressure receiving plate is provided with a pressure receiving plate to be combined and a holding nut that is tightened to a screw portion of the tensioning material to hold the pressure receiving plate in a state of being pressed against the cutting wall side, and the pressure receiving plate is used to pull the tensioning material. It is characterized in that it is divided into a plurality of parts in the circumferential direction that orbits around the axis.

In the present invention, a pressing nut that is tightened to the threaded portion at the other end of the tensioning material in a state where a tensile force is applied is used to press-contact the wall surface of the cutting wall in a state where a plurality of pressure receiving plates divided in the circumferential direction are combined. Being restrained. As a result, the anchor force can be transmitted from the pressure receiving plate to the cutting wall, and the anchor force is applied to the reinforcing anchor to reinforce the cutting wall.
Then, when the shield excavator is dug and the cutting wall is cut with a cutter, the reinforcing anchor is cut from the other end side, the tightening force by the holding nut is reduced, and the frictional resistance between the tension material and the pressure receiving plate is reduced. However, the tensile force (tension force) of the tension material increases. Therefore, when the anchor force (tension force) is released, the pressure receiving plate is not restrained, and a plurality of small pressure receiving plates divided in the circumferential direction are disassembled and fall into the chamber of the shield excavator. .. As described above, in the present invention, since the pressure receiving plate has a divided structure divided into a size that can be taken in by the shield excavator, it is possible to prevent blockage in the chamber, and the reinforcement is efficiently cut. The anchor can be taken into the shield excavator and ejected.
Moreover, the present invention has a simple structure in which the pressure receiving plate is divided in the circumferential direction, and the other anchor configurations are the same as those of the well-known ones, so that there is an advantage that the pressure receiving plate can be constructed without additional steps.

Further, as for the reinforcing anchor, it is preferable that the pressure receiving plate is divided into a plurality of parts in the tension axis direction.

In this case, since the pressure receiving plate is divided into a plurality of parts in both the circumferential direction and the tension axis direction, the pressure receiving plate is decomposed into a smaller size when it falls off from the protruding end of the tension material. Therefore, these disassembled pressure receiving plates can be reliably taken in by the shield excavator, and blockage in the chamber can be prevented more reliably.

Further, in the reinforcing anchor, at least one adjacent pressure receiving plate divided in the tension axis direction is provided with a slip stopper that regulates the movement of the other pressure receiving plate in the direction intersecting the tension axis direction. It is preferable to have.

In the reinforcing anchor, the movement of one pressure receiving plate divided in the tension axis direction in the direction intersecting the tension axis direction is restricted by a slip prevention member provided on the other pressure receiving plate. Therefore, in a state where the anchor force is maintained by the reinforcing anchor, the pressure receiving plates combined by the pressing nuts and divided into a plurality of parts in the circumferential direction can enhance the integrity, and can be applied to the wall surface of the cutting wall without being separated. The restrained state can be maintained.

Further, in the reinforcing anchor, in the adjacent pressure receiving plates divided in the tension axis direction, it is preferable that the circumferential division surfaces divided in the circumferential direction are displaced in the circumferential direction.

In this case, the adjacent pressure receiving plates divided in the tension axis direction can be shifted by, for example, 90 ° in the circumferential direction, and the circumferential division surface between the pressure receiving plates adjacent in the tension axis direction is in the tension axis direction. Since the configuration is not continuous, it is possible to prevent the pressure receiving plate from being disassembled due to the initial load during construction.

Further, it is preferable that the pressure receiving plate, which is divided into the reinforcing anchors, has a shape that can be taken into the machine from the chamber of the shield excavator.

In this case, by dividing the pressure receiving plate into a size corresponding to the size of the intake portion in the chamber of the shield excavator, that is, the soil discharge port, blockage in the chamber can be reliably prevented.

Further, the reinforcing anchor is provided with a machinable core material on the cutting wall, the pressure receiving plate has a laminated plate that abuts on the side surface of the core material, and the laminated plate is the core material. It is preferable that the lumber is divided into a plurality of divided surfaces having a divided surface along a direction orthogonal to the side surface of the above.

In this case, since each of the divided laminated plates can be brought into contact with the side surface of the core material in a direction orthogonal to each other, the core material can be reliably pressed by the pressure receiving plate.

Further, the reinforcing anchor is integrally fitted with the tensioning material in a state where the anchoring material and the protruding end of the anchoring material projecting from the cutting wall are provided with a frictional force exceeding the tensile force, and the reinforcing anchor is integrally fitted on the outer peripheral surface. It is preferable that a tubular grip having a threaded portion and an expandable solidifying material that expands after curing are injected between the protruding end of the anchor material and the tubular grip.

In this case, the expandable solidifying material expands due to hardening, and the protruding end of the anchor material and the tubular grip are integrated by the frictional resistance of the expansion pressure. That is, when constructing the reinforcing anchor, the inflatable solidifying material is injected between the two in a state where the tubular grip is fitted to the outside of the protruding end of the anchor material, so that the two are subjected to a predetermined frictional resistance. Can be more easily integrated.

According to the reinforcing anchor of the present invention, it is possible to suppress an increase in the cost of the shaft, prevent blockage in the chamber of the shield excavator, and suppress a delay in the construction period.

It is a side view which shows the schematic structure of the shaft with the cutting wall by embodiment of this invention. It is the figure which looked at the shaft shown in FIG. 1 from above. It is a front view of the cutting wall reinforced by a plurality of reinforcing anchors. It is a side view of the reinforcing anchor which is constructed on a cutting wall. It is the figure which looked at the reinforcement anchor installed on the cutting wall from above. It is a front view of the reinforcing anchor constructed on the cutting wall. It is a vertical sectional view of the reinforcing anchor shown in FIG. FIG. 7 is a cross-sectional view taken along the line AA shown in FIG. It is a side view explaining the process of cutting a reinforcing anchor constructed on a cutting wall. FIG. 5 is a side view illustrating a process of cutting a reinforcing anchor installed on a cutting wall following FIG. 9. FIG. 5 is a side view illustrating a process of cutting a reinforcing anchor installed on a cutting wall following FIG. 10.

Hereinafter, the reinforcing anchor of the embodiment according to the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the reinforcing anchor 1 according to the present embodiment is provided with a predetermined tensile force by penetrating the cutting wall 3 which is the starting portion of the shield excavator 2 used in the excavation work of the shield tunnel. It is fixed to the ground in a state and is provided so that it can be cut by the shield excavator 2.
The cutting wall 3 is provided as a part of a shaft 30 constructed underground as a starting base of the shield excavator 2, has a cross-sectional shape larger than the outer diameter of the shield excavator 2, and has a cross-sectional shape of the shield excavator 2. It is cut by the cutter 21.

The shaft 30 has a rectangular shape when viewed from above, and a reinforced concrete wall is constructed on a wall surface dug down from the ground. The shield excavator 2 can be arranged in a state of facing the excavation direction, and is necessary for starting. It is built with dimensions that allow the equipment to be installed.

The shaft 30 is not limited to having a rectangular shape when viewed from above, and may be circular. Further, the structure of the shaft 30 is not limited to the reinforced concrete structure, and between a plurality of long H-shaped steels placed as earth retaining along the outer shell of the shaft 30 and the H-shaped steels. It may be a wall filled with concrete or mortar, or a concrete wall sunk with a caisson or the like.

In the shield excavator 2, the cutter 21 is opposed to the face, that is, the wall surface 3a of the cutting wall 3, and the central axis of the shield excavator 2 is the central axis of the tunnel on the starting platform 32 provided on the bottom of the shaft 30. It is placed in a state that matches.

The cutting wall 3 is, for example, a SEW wall (a wall constructed by the SEW (Sheeld Earth Retaining Wall System) method owned by Sekisui Chemical Industry Co., Ltd.) formed of a composite material in which hard urethane resin is reinforced with long glass fibers, and H-shaped steel. Shield starting / reaching retaining walls such as concrete reinforced with FRP or carbon fiber can be adopted.
Further, the cutting wall 3 is reinforced by a plurality of excavable reinforcing anchors 1, 1, ... Made of a composite material in which polyester resin is reinforced with long glass fibers or carbon fibers.

As shown in FIG. 3, in the cutting wall 3, a plurality of core materials for forming a cutting portion (hereinafter, referred to as “core material 34”) extending in the vertical direction are arranged at predetermined intervals in the horizontal direction, and the core material 34 A cement-hardened portion 35 made of only a hardened soil cement is provided between the 34's.
The core material 34 is a columnar composite material in which hard urethane resin, which is a material that can be cut by the cutter 21 of the shield excavator 2, is reinforced with long glass fibers (the core material 34 is not particularly limited depending on the size of the ground and the shaft at the construction site, but is not particularly limited, for example. It is obtained by fixing H-shaped steels above and below a 600 x 300 mm Sekisui Chemical Industry Co., Ltd., Eslon Neo Lumber FFU) via joints, bolts and nuts, and the like.

As shown in FIGS. 4 to 7, in the reinforcing anchor 1, the fixing end 11b (see FIGS. 1 and 2) on one end side is fixed to the ground G by a fixing material, and the other end (protruding end 11a) side is cut. A tendon grip 12 (see FIG. 7) that integrally fits the anchor material 11 protruding from the wall 3 and the protruding end 11a of the anchor material 11 with a frictional force exceeding the tensile force, and has a threaded portion 12a (see FIG. 7) on the outer peripheral surface. (Cylindrical grip), a pressure receiving plate 4 that is fitted to the outside of the tendon grip 12 and press-contacts the wall surface 3a of the cutting wall 3, and a pressure receiving plate 4 that is tightened to the threaded portion 12a of the tendon grip 12 to bring the pressure receiving plate 4 to the cutting wall 3 side. It is provided with a pressing nut 13 that holds the presser nut 13 in a state of being pressed against the surface.
Here, the anchor material 11 and the tendon grip 12 form a tension material.

As shown in FIG. 1, the anchor material 11 functions as a pulling material composed of stranded carbon fibers that can be cut, and an anchor fixing hole 31 (a hole is formed from the wall surface 3a side of the cutting wall 3 to the ground G on the back surface side) ( (See FIG. 7), and the tip portion (fixing end 11b) is fixed by the grout 16 filled in the anchor fixing hole 31 in the fixing ground G. The anchor material 11 can apply a tensile tension that causes the wall surface 3a of the cutting wall 3 to be pressed against the wall surface 3a of the cutting wall 3 with a force that can withstand earth pressure or water pressure via the pressure receiving plate 4. The anchor material 11 of the present embodiment is arranged diagonally downward from the inside of the shaft 30.
Then, the portion of the anchor material 11 other than the protruding end 11a and the fixing end 11b is inserted into a sheath pipe 15 such as a corrugated rigid polyethylene pipe and is not fixed to the grout 16 filled in the anchor fixing hole 31. It has become.

As shown in FIGS. 7 and 8, the tendon grip 12 is integrally provided at the protruding end 11a of the anchor material 11 via the fixing expansion mortar 14 (expandable solidifying material). The tendon grip 12 is made of a machinable material such as FRP, and is threaded on the outer peripheral surface so that the holding nut 13 can be screwed. In the state where the pressure receiving plate 4 and the pressing nut 13 are attached, the fixing expansion mortar 14 is injected between the tendon grip 12 and the protruding end 11a of the anchor material 11 and is cured in the expanded state. Since the fixing expansion mortar 14 expands as it hardens, the protruding end 11a of the anchor material 11 and the tendon grip 12 are integrally brought into close contact with each other due to the expansion, and the tendon grip 12 is fixed to the pressure receiving plate 4 by frictional force. .. As the fixing expansion mortar 14, a known one used in a general anchoring method can be used.

The press nut 13 is made of a machinable material such as FRP, and can be screwed into the threaded portion 12a on the outer peripheral surface of the tendon grip 12 as described above. By tightening the pressing nut 13, the pressure receiving plate 4 can be pressed against the wall surface 3a side of the cutting wall 3 in the tension axis O direction. That is, the pressure receiving plate 4 is sandwiched between the pressure receiving plate 4 and the cutting wall 3 by tightening the pressing nut 13.

Next, the configuration of the pressure receiving plate 4 will be specifically described.
As shown in FIG. 6, the pressure receiving plate 4 is divided into a plurality of (three in this case) along the tension axis O direction, and the divided pressure receiving plates 4 (first pressure receiving plate 41 and second pressure receiving plate described later). 42 and the laminated plate 43) are each divided into a plurality (two) in the circumferential direction around the tension axis O of the anchor material 11.
Specifically, the pressure receiving plate 4 is formed of a machinable material such as FRP, and of the first pressure receiving plate 41, the second pressure receiving plate 42, and the laminated plate 43 from the pressing nut 13 toward the cutting wall 3 in the tension axis O direction. They are arranged in order and divided into three members. The first pressure receiving plate 41, the second pressure receiving plate 42, and the laminated plate 43 are formed in a rectangular shape when viewed from the tension axis O direction, and the first pressure receiving plate 41 and the second pressure receiving plate 42 have the same shape.

As shown in FIG. 7, the first pressure receiving plate 41 and the second pressure receiving plate 42 are provided so that the insertion holes 41a and 42a through which the tendon grip 12 can be inserted are coaxial with each other. The inner diameters of the insertion holes 41a and 42a are substantially the same as the outer diameter of the tendon grip 12. The first pressure receiving plate 41 is formed in a plate shape having the same thickness as a whole along the hole axis direction of the insertion hole 41a. That is, both end faces 41b and 41c in the hole axis direction are flat surfaces orthogonal to the length direction (tension axis O) of the anchor material 11 with the first pressure receiving plate 41 externally fitted to the tendon grip 12. The second pressure receiving plate 42 has a first end surface 42b that abuts on the first pressure receiving plate 41 in the hole axis direction in a state of being fitted onto the tendon grip 12 so as to form a plane orthogonal to the tension axis O and abut on the laminated plate 43. The second end surface 42c intersects the tension axis O at an angle and forms a plane parallel to the plane direction (that is, the vertical direction) of the wall surface 3a of the cutting wall 3.

The laminated plate 43 has a plate shape, and an insertion hole 43a through which the tendon grip 12 can be inserted is formed in the center thereof. In the laminated plate 43, one of the first plate surfaces 43b is in contact with the second end surface 42c of the second pressure receiving plate 42, and the other second plate surface 43c is the wall surface of the cutting wall 3 in a state where the laminated plate 43 is externally fitted to the tendon grip 12. Of 3a, it is configured to abut on the side surface of the core material.

As shown in FIGS. 4 to 6, the first pressure receiving plate 41, the second pressure receiving plate 42, and the laminated plate 43 are each divided into two in the circumferential direction at a position passing through the center. Here, in the first pressure receiving plate 41, the second pressure receiving plate 42, and the laminated plate 43, the surface divided in the circumferential direction is referred to as a circumferential divided surface. The first pressure receiving plate 41 and the second pressure receiving plate 42 adjacent to each other in the tension axis O direction are assembled in a state in which the circumferentially divided surfaces 41d and 42d are displaced by 90 ° in the circumferential direction.

The first pressure receiving plate 41, the second pressure receiving plate 42, and the laminated plate 43 are divided into shapes and sizes that can be taken into the machine from the chamber 22 (see FIG. 2) of the shield excavator 2. There is. For example, by dividing into a shape and size having an outer diameter of 430 mm and a length of 860 mm or less, it can be taken in by a general shield excavator 2. Therefore, in the present embodiment, each of the first pressure receiving plate 41, the second pressure receiving plate 42, and the laminated plate 43 is divided into two in the circumferential direction, but the number of divisions in the circumferential direction is divided into, for example, three according to the intake form. It is also possible to change to or quadrant.

The parts constituting the first pressure receiving plate 41, the second pressure receiving plate 42, and the laminated plate 43 may be provided with a positioning structure for determining the mounting position or temporarily fixing the parts.
As shown in FIG. 4, the second pressure receiving plate 42 has a first slip stopper that regulates lateral movement of the first pressure receiving plate 41 located on the tension side in the tension axis O direction in a direction orthogonal to the tension axis O. A member 44 is provided. Two first displacement prevention members 44 are provided for each side of the outer peripheral edge of the first end surface 42b of the second pressure receiving plate 42, and project out toward the tension side in the tension axis O direction. That is, in the state where the first pressure receiving plate 41 is combined with the second pressure receiving plate 42, the outer peripheral surface of the first pressure receiving plate 41 is pressed from the outside by the plurality of first displacement prevention members 44, and the lateral movement is restricted. There is.

Further, the laminated plate 43 is also provided with a second slip prevention member 45 similar to the first slip prevention member 44 of the second pressure receiving plate 42, in a direction orthogonal to the tension axis O of the second pressure receiving plate 42. It is configured to regulate lateral movement. Two second slip prevention members 45 are provided for each side of the outer peripheral portion of the first plate surface 43b, and project toward the tension side in the tension axis O direction. That is, in the state where the second pressure receiving plate 42 is combined with the laminated plate 43, the outer peripheral surface of the second pressure receiving plate 42 is pressed from the outside by the plurality of second slip prevention members 45, and the lateral movement is restricted.

Next, a method of constructing a plurality of reinforcing anchors 1 on the cutting wall 3, that is, a construction of reinforcing the cutting wall 3 of the shaft 30 by using the reinforcing anchor 1 will be described with reference to the drawings.
First, as shown in FIGS. 1 and 2, an anchor fixing hole 31 having a predetermined length that penetrates the cutting wall 3 at a plurality of preset positions of the constructed cutting wall 3 and reaches the fixing ground G is cut. Drill holes using a drilling machine. Specifically, in the cement-hardened portion between the core members 34, 34 of the cutting wall 3 (see FIG. 3), a drill is used to drill a hole at an inclination angle of, for example, 5 to 45 degrees downward.

Then, as shown in FIG. 7, the tip of the anchor material 11 partially covered with the sheath tube 15 reaches the tip of the anchor fixing hole 31, and the protruding end 11a of the anchor material 11 is the wall surface of the cutting wall 3. It is inserted into the anchor fixing hole 31 with a protruding length that protrudes from 3a and secures a tightening length of the holding nut 13. At this time, the sheath pipe 15 is arranged so as to have a predetermined length from the cutting wall 3 toward the fixing ground G side.

After that, the fixing material (grout 16) is injected into the anchor fixing hole 31 into which the anchor material 11 is inserted. At this time, the grout 16 is prevented from entering the inside of the sheath tube 15. As a result, the fixing end 11b (see FIGS. 1 and 2) on the tip end side of the anchor material 11 is integrally fixed and fixed in the anchor fixing hole 31 with the fixing ground G as the grout 16 is hardened.

Next, the tendon grip 12 is fitted to the protruding end 11a of the anchor material 11 from the outside, the pressure receiving plate 4 and the bearing plate 17 are inserted into the outside of the tendon grip 12 in this order, and the pressing nut 13 is further inserted into the tendon grip 12. It is screwed into the threaded portion 12a on the outer peripheral surface of the above.

Then, the fixing expansion mortar 14 is injected between the tendon grip 12 and the protruding end 11a of the anchor material 11 and cured. At this time, the fixing expansion mortar 14 expands, and the protruding end 11a of the anchor material 11 and the tendon grip 12 are fixed in a state of being adhered to each other, and are integrated in a close state by the frictional force due to the expansion pressure. Then, after a predetermined frictional force is obtained by expanding and hardening the fixing expansion mortar 14, the portion of the tendon grip 12 protruding from the holding nut 13 is gripped by a jack-up device (not shown) to pull the anchor material 11. A tension force is applied in the pulling direction to bring the tension state into a predetermined state, and the pressing nut 13 is tightened to the cutting wall 3 side to maintain the tension state. As a result, the pressure receiving plate 4 can be brought into pressure contact with the cutting wall 3.
As a result, the cutting wall 3 can be reinforced by the plurality of anchor materials 11, 11, ..., And the cutting wall 3 is in a completed state.

As described above, in the present embodiment, the pressure receiving force is divided into a plurality of parts in the circumferential direction by the pressing nut 13 tightened to the tendon grip 12 fixed to the protruding end 11a of the anchor material 11 in the state where the tension force is applied. In a state where the plates 4 are combined, they are pressed against the wall surface 3a of the cutting wall 3 and restrained. As a result, the anchor force can be transmitted from the pressure receiving plate 4 to the cutting wall 3, and the anchor force is applied to the reinforcing anchor 1 to reinforce the cutting wall 3.
Since the cutting wall 3 configured in this way is reinforced by a plurality of reinforcing anchors 1, it is possible to prevent the cutting wall 3 from bending inward of the shaft 30 due to soil water pressure.

Next, a method of cutting the cutting wall 3 reinforced by the plurality of reinforcing anchors 1 having the above-described configuration with the shield excavator 2 and its operation will be described in detail with reference to the drawings.
First, as shown in FIGS. 1 and 2, a starting pedestal 32 on which the shield excavator 2 is mounted is installed on the bottom of the shaft 30, and the cutter 21 is opposed to the cutting wall 3 on the starting pedestal 32. Install the shield excavator 2 in this state. Then, all preparations such as a drive device for starting the shield excavator 2 are completed.

Subsequently, the cutter 21 of the shield excavator 2 is rotated, and the reaction force wall 33 installed at a position facing the cutting wall 3 behind the shield excavator 2 in the shaft 30 is subjected to a propulsion reaction force to start the shaft. .. In the case of the shield excavator 2 having a structure that takes a reaction force in the lateral direction (diameter direction), a reaction force wall is installed on the side of the shield excavator 2.

Then, as shown in FIG. 9, the shield excavator 2 is excavated and the cutting wall 3 is cut by the cutter 21. At this time, when the tendon grip 12 is cut to a predetermined length from the protruding end 11a side of the reinforcing anchor 1, the tightening force by the pressing nut 13 decreases, and the frictional resistance between the anchor material 11 and the tendon grip 12 increases. Also, the tensile force (tension force) of the anchor material 11 becomes large. Therefore, as shown in FIG. 10, the edge between the tendon grip 12 and the anchor material 11 is cut off, the fixed state of both is released, and the tendon grip 12 and the anchor material 11 are separated. Then, when the anchor force (tension force) is released, the pressure receiving plate 4 is no longer restrained, and a plurality of pressure receiving plates 4 (first pressure receiving plate 41, second pressure receiving plate 42, and laminated plate 43) divided in the circumferential direction are not restrained. ) Disassembles and falls into the chamber 22 (see FIG. 1) of the shield excavator 2. For example, when the length of the tendon grip 12 is 400 mm, when 200 mm, which is half the length of the tendon grip 12, is cut, the above-mentioned action occurs, and the first pressure receiving plate 41 and the second pressure receiving plate 41 and the second pressure receiving plate are divided into a plurality of parts. The plate 42 and the laminated plate 43 will fall off.
Next, after the plurality of divided pressure receiving plates 4 have fallen off, as shown in FIG. 11, the remaining tendon grip 12 is pulled from the anchor material 11 together with the holding nut 13 by the impact of the cutter 21 of the shield excavator 2. It comes off and falls out.

As described above, in the present embodiment, since the pressure receiving plate 4 has a divided structure divided into a size that can be taken in by the shield excavator 2, it is possible to prevent blockage in the chamber 22 and to improve efficiency. The well-cut reinforcing anchor 1 can be taken into the shield excavator 2 and discharged.
Moreover, in the present embodiment, the pressure receiving plate 4 has a simple structure of being divided in the circumferential direction, and the other anchor configurations are the same as those of the well-known ones, so that there is an advantage that the pressure receiving plate 4 can be constructed without additional steps. ..

Further, in the present embodiment, since the pressure receiving plate 4 is divided into a plurality of portions in both the circumferential direction and the tension axis O direction, the pressure receiving plate 4 becomes smaller in size when it falls off from the protruding end 11a of the anchor material 11. It is disassembled. Therefore, these disassembled pressure receiving plates 4 can be reliably taken in by the shield excavator 2, and blockage in the chamber 22 can be prevented more reliably.

Further, in the present embodiment, the movement of the first pressure receiving plate 41 in the direction of intersecting the tension axis O direction is restricted by the first slip prevention member 44 provided on the second pressure receiving plate 42. Further, the movement of the second pressure receiving plate 42 in the direction of intersecting the tension axis O direction is restricted by the second slip prevention member 45 provided on the laminated plate 43. Therefore, in a state where the anchor force is maintained by the reinforcing anchor 1, the pressure receiving plate 4 divided into a plurality of parts in the circumferential direction combined by the pressing nut 13 can enhance the integrity, and the cutting wall is not separated. The restrained state with respect to the wall surface 3a of 3 can be maintained.

Further, in the present embodiment, the circumferentially divided surfaces 41d and 42d of the adjacent first pressure receiving plate 41 and the second pressure receiving plate 42 divided in the tension axis O direction are shifted by, for example, 90 ° in the circumferential direction. Since the circumferential division surfaces 41d and 42d are not continuous in the tension axis O direction, it is possible to prevent the pressure receiving plate 4 from being disassembled due to the initial load during construction.

Further, in the present embodiment, since the divided pressure receiving plate 4 is divided into a shape that can be taken into the machine from the chamber 22 of the shield excavator 2, the take-in portion in the chamber 22 of the shield excavator 2, that is, By dividing the pressure receiving plate 4 into a size corresponding to the size of the soil discharge port, blockage in the chamber 22 can be reliably prevented.

Further, in the present embodiment, the laminated board 43 has a divided surface along a direction orthogonal to the side surface of the core material and is divided into a plurality of parts, and each of the divided laminated plates 43 is orthogonal to the side surface of the core material. Since the contact can be made in the direction in which the core material is formed, the core material can be reliably pressed by the pressure receiving plate 4.

Further, in the present embodiment, the fixing expansion mortar 14 that expands after curing is injected between the protruding end 11a of the anchor material 11 and the tendon grip 12, and the fixing expansion mortar 14 expands due to curing. The protruding end 11a of the anchor material 11 and the tendon grip 12 are integrated by the frictional resistance of the expansion pressure. That is, when constructing the reinforcing anchor 1, the tendon grip 12 is fitted to the outside of the protruding end 11a of the anchor material 11, and the fixing expansion mortar 14 is injected between the two to hold both. It can be easily integrated by a predetermined frictional resistance.

Although the embodiment of the reinforcing anchor according to the present invention has been described above, the present invention is not limited to the above-described embodiment and can be appropriately modified without departing from the spirit of the present invention.
For example, in the above-described embodiment, the starting shaft is the target of the cutting wall 3, but the reaching shaft can also be the target of the cutting wall.

Further, in the present embodiment, the pressure receiving plate 4 is divided into three parts along the tension axis O direction, and the first pressure receiving plate 41, the second pressure receiving plate 42, and the laminated plate 43 are provided. The number of divisions along the axis O direction is not limited to this, and the configuration may not be divided along the tension axis O direction. The point is that the pressure receiving plate 4 only needs to be divided in the circumferential direction.

Further, in the present embodiment, the slip stoppers 44, 45 that regulate the movement of at least one adjacent pressure receiving plate divided in the tension axis O direction in the direction intersecting the tension axis O direction in the other pressure receiving plate. However, it is also possible to omit such slip prevention members 44 and 45. Further, the positions and quantities of the slip prevention members 44 and 45 are not limited to the above-described embodiment.

Furthermore, in the present invention, in the adjacent first pressure receiving plate 41 and the second pressure receiving plate 42 divided in the tension axis O direction, the circumferentially divided surfaces 41d and 42d, which are divided in the circumferential direction, are in the circumferential direction. Although the configuration is deviated, the angle of the deviation in the circumferential direction can be set as appropriate, and the configuration that does not have such a deviation, that is, the circumferential division surfaces 41d and 42d are aligned with each other in the tensile axis O direction. May be good.
Further, when the pressure receiving plate 4 is divided when being scraped by the cutter 21 of the shield excavator 2 as in the present embodiment, the first pressure receiving plate 41, the second pressure receiving plate 42, and the laminated plate 43 are configured. Parts to be used may be temporarily fixed with an adhesive.

Further, the configuration is not limited to a configuration in which an expansion mortar (expandable solidifying material) for fixing that expands after curing is injected between the protruding end 11a of the anchor material 11 and the tubular grip composed of the tendon grip 12. It is also possible to use a solidifying material that is adhered by curing.

Further, it is possible to replace the components in the above-described embodiment with well-known components as appropriate without departing from the spirit of the present invention.

1 Reinforcement anchor 2 Shield excavator 3 Cutting wall 4 Pressure receiving plate 11 Anchor material 12 Tendon grip (cylindrical grip)
13 Holding nut 14 Expansion mortar for fixing (expandable solidifying material)
30 Shaft sink 31 Anchor fixing hole 41 1st pressure receiving plate 42 2nd pressure receiving plate 43 Laminated plate 44, 45 Anti-slip member G Fixing ground O Tension shaft

Claims (5)

A reinforcing anchor that penetrates a cutting wall that can be cut by a shield excavator, is fixed to the ground in a state where a predetermined tensile force is applied, and can be cut by the shield excavator.
One end side in the tension axis direction is fixed to the ground by a fixing material, and the other end side protrudes from the cutting wall and has a threaded portion on the outer peripheral surface.
A pressure receiving plate fitted to the outside of the tension material and
A holding nut that is tightened into the threaded portion of the pulling material and holds the pressure receiving plate in a state of being pressed against the cutting wall side.
With
The pressure receiving plate is divided into a plurality of pieces in the circumferential direction around the tension axis of the tension material .
The pressure receiving plate is divided into a plurality of parts in the tension axis direction.
In the adjacent pressure receiving plates divided in the tension axis direction, the reinforcing anchors are characterized in that the circumferentially divided surfaces divided in the circumferential direction are displaced in the circumferential direction. At least one of the adjacent pressure receiving plates divided in the tension axis direction is provided with a slip stopper that regulates the movement of the other pressure receiving plate in the direction intersecting the tension axis direction. The reinforcing anchor according to claim 1. A reinforcing anchor that penetrates a cutting wall that can be cut by a shield excavator, is fixed to the ground in a state where a predetermined tensile force is applied, and can be cut by the shield excavator.
One end side in the tension axis direction is fixed to the ground by a fixing material, and the other end side protrudes from the cutting wall and has a threaded portion on the outer peripheral surface.
A pressure receiving plate fitted to the outside of the tension material and
A holding nut that is tightened into the threaded portion of the pulling material and holds the pressure receiving plate in a state of being pressed against the cutting wall side.
With
The pressure receiving plate is divided into a plurality of pieces in the circumferential direction around the tension axis of the tension material .
The divided pressure receiving plate is a reinforcing anchor having an outer diameter of 430 mm and a length of 860 mm or less. The cutting wall is provided with a core material that can be cut.
The pressure receiving plate has a laminated plate that abuts on the side surface of the core material.
The reinforcing anchor according to any one of claims 1 to 3 , wherein the laminated board has a dividing surface along a direction orthogonal to the side surface of the core material and is divided into a plurality of parts. .. The tension material is integrally fitted with the anchor material in a state where a frictional force exceeding the tensile force is applied to the protruding end of the anchor material protruding from the cutting wall, and has a tubular shape having the threaded portion on the outer peripheral surface. With a grip,
The reinforcing anchor according to any one of claims 1 to 4 , wherein an expandable solidifying material that expands after curing is injected between the protruding end of the anchor material and the tubular grip.

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