JP2019027011A - Reinforced anchor - Google Patents

Abstract

To provide a reinforced anchor which inhibits an increase in cost of a vertical shaft, can prevent the inside of a chamber of a shield drilling machine from closing, and can inhibit a delay of a construction period.SOLUTION: There is provided a reinforced anchor which comprises: an anchor member 11 which makes one end side of a tension axis O direction fix to the ground by a fixation member, of which the other end side protrudes from a cutting wall 3, and to which a tendon grip 12 having a screw portion 12a on a peripheral face is fitted from the outside integrally; a pressure receiving board 4 which is fitted to the outside of the tendon grip 12; and a presser nut 13 which is tighten by the screw portion 12a of the tendon grip 12 and holds the pressure receiving board 4 in a state of being brought into pressure-contact with the cutting wall 3 side. The pressure receiving board 4 is configured to be divided into plural pieces in the circumferential direction of turning around the tension axis O of the anchor member 11.SELECTED DRAWING: Figure 7

Description

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

Conventionally, as a tunnel wall for shield digging used when constructing underground tunnels and sewage mains by the shield method, for example, as shown in Patent Documents 1 and 2, a composite in which a hard urethane resin is reinforced with long glass fibers A cutting wall made of a material and made of a member that can be cut by a cutter of a shield excavator is used.
However, when the shield outer diameter is large or the underground depth of the start reaching part is deep, the soil water pressure applied to the cutting wall from the ground around the shaft becomes large, and the deflection of the cutting wall to the inside of the shaft increases. Construction becomes difficult. Therefore, it is conceivable to suppress the above-described deflection by increasing the wall thickness of the cutting wall to increase the strength. However, the wall thickness of the entire shaft is increased, 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 cutable anchor or beam, or a removable anchor that can be removed before cutting. Furthermore, by suppressing the wall thickness of the cutting wall to be small, it is possible to apply even under conditions where the shield outer diameter is large and the depth is deep, and a shield tunneling shaft wall with reduced cost is employed.

JP-A-8-303178 Japanese Patent Laid-Open No. 9-013875

  However, when reinforcing the conventional cutting wall as described above with an anchor, when excavation by the shield excavator proceeds 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 for cutting the pressure receiving plate cannot be obtained, and the uncut pressure receiving plate falls into the chamber near the cutter of the shield excavator, resulting in blockage in the chamber and delaying the work period. There was a problem.

  Therefore, the present invention has been made in view of the above-described problems, and can suppress an increase in the cost of the shaft, can prevent blockage in the chamber of the shield excavator, and can suppress a delay in the construction period. It aims to provide a reinforced anchor.

  In order to achieve the above object, the reinforcing anchor according to the present invention is fixed to the ground in a state where a predetermined tensile force is applied through a cutting wall that can be cut by a shield excavator and can be cut by the shield excavator. A reinforcing anchor that has one end side in the direction of the tensile axis fixed to the ground by a fixing material, the other end side protruding from the cutting wall and having a threaded portion on the outer peripheral surface, and fitted on the outside of the tensioning material. A pressure receiving plate to be joined, and a holding nut that is fastened to a threaded portion of the tensile material and holds the pressure receiving plate in pressure contact with the cutting wall side, and the pressure receiving plate is a tensile member of the tensile material. It is characterized by being divided into a plurality of circumferential directions that circulate around the axis.

In the present invention, a pressure nut that is tightened to the threaded portion at the other end of the tensile material in a state where a tensile force is applied is pressed against the wall surface of the cutting wall in a state where the pressure receiving plates divided into a plurality of circumferential directions are combined. And is restrained. As a result, the anchor force can be transmitted from the pressure receiving plate to the cutting wall, and the anchoring force is applied to the reinforcing anchor to reinforce the cutting wall.
And when digging the shield excavator and cutting the cutting wall 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 tensile material and the pressure receiving plate However, the tensile force (tensile force) of the tensile material increases. Therefore, the pressure receiving plate is not restrained when the anchor force (tension force) is released, 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 that is divided into a size that can be taken in by the shield excavator, it is possible to prevent blockage in the chamber and efficiently cut the reinforcement. The anchor can be taken into the shield excavator and discharged.
In addition, the present invention has a simple structure in which the pressure receiving plate is divided in the circumferential direction, and the other anchor configuration has the same configuration as a well-known one, so that there is an advantage that construction can be performed without an additional process.

  In the reinforcing anchor, it is preferable that the pressure receiving plate is divided into a plurality of portions in the tensile axis direction.

  In this case, since the pressure receiving plate is divided into a plurality of directions in both the circumferential direction and the tension axis direction, the pressure receiving plate is further broken down when it falls off from the protruding end of the tension member. Therefore, these decomposed 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 displacement preventing member that restricts the movement of the other pressure receiving plate in the direction intersecting the tension axis direction. Preferably it is.

  In the reinforcing anchor, movement of one pressure receiving plate divided in the tensile axis direction in a direction intersecting the tensile axis direction is restricted by a displacement preventing member provided on the other pressure receiving plate. Therefore, in the state in which the anchor force is maintained by the reinforcing anchor, the pressure receiving plate divided into a plurality of circumferential directions combined by the presser nut can enhance the integrity, and without separating, against the wall surface of the cutting wall The restraint state can be maintained.

  Moreover, it is preferable that each circumferential direction division surface divided | segmented by the said circumferential direction has shifted | deviated to the said circumferential direction in the adjacent pressure receiving plate divided | segmented by the said tension axis direction.

  In this case, the adjacent pressure receiving plates divided in the tensile axis direction can be shifted, for example, by 90 ° in the circumferential direction, and the circumferential dividing surfaces of the pressure receiving plates adjacent in the tensile axis direction are in the tensile axis direction. Since it becomes the structure which is not continuous, it can suppress that a pressure receiving plate decomposes | disassembles by the initial load at the time of construction.

  Moreover, it is preferable that the said pressure receiving plate into which the reinforcement anchor is divided | segmented has comprised the shape which can be taken in into the machine from the chamber of the said 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 size of the soil discharge port, blockage in the chamber can be reliably prevented.

  In the reinforcing anchor, the cutting wall is provided with a core material that can be cut, and the pressure receiving plate includes a laminated plate that abuts against a side surface of the core material, and the laminated plate comprises the core material. It is preferable that it is divided into a plurality of parts having a dividing surface along a direction orthogonal to the side surface.

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

  Further, the reinforcing anchor is integrally fitted with the tensile material in a state where a frictional force exceeding the tensile force is applied to the anchor material and a protruding end of the anchor material protruding from the cutting wall, and the outer peripheral surface is It is preferable that an inflatable solidified material that is inflated after curing is injected between the protruding end of the anchor material and the cylindrical grip.

  In this case, the expandable solidified material expands by curing, so that the protruding end of the anchor material and the cylindrical grip are integrated by the frictional resistance of the expansion pressure. In other words, when constructing a reinforcing anchor, in a state where the cylindrical grip is fitted to the outside of the protruding end of the anchor material, an inflatable solidifying material is injected between the two so that both have a predetermined friction resistance. Can be easily integrated.

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

It is a side view which shows schematic structure of the shaft provided with the cutting wall by embodiment of this invention. It is the figure which looked at the shaft shown in FIG. 1 from upper direction. It is a front view of the cutting wall reinforced with a plurality of reinforcement anchors. It is a side view of the reinforcement anchor currently constructed in the cutting wall. It is the figure which looked at the reinforcement anchor currently constructed in the cutting wall from the upper part. It is a front view of the reinforcement anchor currently constructed | assembled by the cutting wall. It is a longitudinal cross-sectional view of the reinforcement anchor shown in FIG. It is the sectional view on the AA line shown in FIG. It is a side view explaining the process of cutting the reinforcement anchor currently constructed in the cutting wall. It is a side view explaining the process of cutting the reinforcement anchor currently constructed in the cutting wall following FIG. It is a side view explaining the process of cutting the reinforcement anchor currently constructed in the cutting wall following FIG.

  Hereinafter, the reinforcement anchor of embodiment by this invention is described in detail based on drawing.

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

  The vertical shaft 30 has a rectangular shape in a top view, and is constructed of a reinforced concrete wall on a wall dug down from the ground. The shield excavator 2 can be arranged with the direction of the excavation direction and is necessary for starting. It is constructed with dimensions that allow installation of equipment.

  Note that the vertical shaft 30 is not limited to a rectangular shape when viewed from above, and may be circular. Furthermore, the structure of the vertical shaft 30 is not limited to being reinforced concrete, but between a plurality of long H-section steels cast as earth retaining along the outline of the vertical shaft 30 and the H-shaped steels. It may be a wall filled with concrete or mortar, or a concrete wall submerged with a caisson or the like.

  The shield excavator 2 is configured such that the cutter 21 is opposed to the face, that is, the wall surface 3a of the cutting wall 3 on the start frame 32 provided on the bottom plate of the shaft 30, and the central axis of the shield excavator 2 is the tunnel central axis. It is arranged in a state that matches.

The cutting wall 3 is, for example, a SEW wall (a wall constructed by SEW (Shield Earth Retaining Wall System) method owned by Sekisui Chemical Co., Ltd.) formed from a composite material in which hard urethane resin is reinforced with long glass fibers, H-section steel It is possible to employ a shield retaining and retaining earth retaining wall such as concrete reinforced with FRP of a mold or carbon fiber.
The cutting wall 3 is reinforced by a plurality of excavable reinforcing anchors 1, 1,... Made of a composite material in which a polyester resin is reinforced with long glass fibers or carbon fibers.

As shown in FIG. 3, the cutting wall 3 includes a plurality of cutting portion forming core members (hereinafter referred to as “core members 34”) extending in the vertical direction and arranged at predetermined intervals in the horizontal direction. , 34 is provided with a cement hardening part 35 made of only a soil cement hardened body.
The core material 34 is a columnar composite material in which a 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 (although it is not particularly limited depending on the size of the ground or shaft of the construction site, for example, H-shaped steel is obtained by fixing H-shaped steel on the top and bottom of 600 × 300 mm Sekisui Chemical Co., Ltd., Eslon Neo Lumber FFU) via joints, bolts and nuts, and the like.

As shown in FIGS. 4 to 7, the reinforcing anchor 1 fixes the fixing end 11b (see FIGS. 1 and 2) on one end side to the ground G with a fixing material and cuts the other end (projecting end 11a) side. An anchor material 11 projecting from the wall 3 and a tendon grip 12 (see FIG. 7) having a threaded portion 12a (see FIG. 7) on the outer peripheral surface are integrally fitted to the projecting end 11a of the anchor material 11 with a frictional force exceeding the tensile force. A cylindrical grip), a pressure receiving plate 4 fitted to the outside of the tendon grip 12 and press-contacting the wall surface 3a of the cutting wall 3, and a screw 12a of the tendon grip 12 to be tightened to the pressure receiving plate 4 on the cutting wall 3 side. And a holding nut 13 that is held in pressure contact therewith.
Here, the anchor material 11 and the tendon grip 12 constitute a tensile material.

As shown in FIG. 1, the anchor material 11 functions as a tensile material made of a strand of carbon fiber that can be cut, and has an anchor fixing hole 31 (drilled from the wall surface 3 a side of the cutting wall 3 to the ground G on the back surface side. 7 (see FIG. 7), and the front end portion (fixing end 11b) is fixed on the fixing ground G by the grout 16 filled in the anchor fixing hole 31. The anchor material 11 can apply a tensile tension that presses the wall surface 3 a of the cutting wall 3 with a force that can withstand earth pressure or water pressure via the pressure receiving plate 4. In addition, the anchor material 11 of this Embodiment is arrange | positioned toward the diagonally downward direction from the inside of the shaft 30. FIG.
A portion of the anchor material 11 excluding the protruding end 11a and the fixing end 11b is inserted into a sheath tube 15 such as a corrugated hard polyethylene tube 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 on the protruding end 11 a of the anchor material 11 via a fixing expansion mortar 14 (expandable solidified material). The tendon grip 12 is made of a material that can be cut, such as FRP, and is threaded so that a pressing nut 13 can be screwed onto the outer peripheral surface thereof. In a state where the pressure receiving plate 4 and the presser nut 13 are mounted, a 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 an 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 by expansion, and the tendon grip 12 is fixed to the pressure receiving plate 4 by frictional force. . The fixing expansion mortar 14 may be a known one used in a general anchor method.

  The presser nut 13 is made of a material that can be cut, such as FRP, and can be screwed into the threaded portion 12 a on the outer peripheral surface of the tendon grip 12 as described above. By tightening the presser nut 13, the pressure receiving plate 4 can be pressed against the wall surface 3 a side of the cutting wall 3 in the direction of the pulling axis O. That is, the pressure receiving plate 4 is sandwiched between the cutting wall 3 by tightening the presser 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 (here, three) along the direction of the tension axis O, 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 material that can be cut such as FRP, and the first pressure receiving plate 41, the second pressure receiving plate 42, and the laminated plate 43 are formed in the direction of the tensile axis O from the holding nut 13 toward the cutting wall 3. 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 direction of the tension axis O, 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 insertion holes 41 a and 42 a through which the tendon grip 12 can be inserted are coaxial. The inner diameters of these insertion holes 41 a and 42 a 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 along the axial direction of the insertion hole 41a. That is, both end surfaces 41b and 41c in the hole axis direction are planes orthogonal to the length direction (pull axis O) of the anchor material 11 in a state where the first pressure receiving plate 41 is externally fitted to the tendon grip 12. When the second pressure plate 42 is fitted on the tendon grip 12, the first end surface 42 b that contacts the first pressure plate 41 in the hole axis direction forms a plane perpendicular to the pull axis O and contacts the laminated plate 43. The second end face 42c obliquely intersects the tension axis O 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 at the center. In the state where the laminated plate 43 is externally fitted to the tendon grip 12, one first plate surface 43 b comes into contact with the second end surface 42 c of the second pressure receiving plate 42, and the other second plate surface 43 c is the wall surface of the cutting wall 3. It is comprised so that it may contact | abut to the side surface of a core material among 3a.

  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 positions passing through the center. Here, in the 1st pressure receiving plate 41, the 2nd pressure receiving plate 42, and the laminated board 43, the surface divided | segmented into the circumferential direction is called circumferential direction division surface. The first pressure receiving plate 41 and the second pressure receiving plate 42 that are adjacent to each other in the direction of the pulling axis O are assembled in a state in which the circumferential division surfaces 41d and 42d are shifted by 90 ° in the circumferential direction.

  In addition, what was divided | segmented in the 1st pressure receiving plate 41, the 2nd pressure receiving plate 42, and the laminated board 43 is divided | segmented into the shape and magnitude | size which can be taken in into the machine from the chamber 22 (refer FIG. 2) of the shield excavator 2. FIG. Yes. For example, by dividing into a shape and size having an outer diameter of 430 mm and a length of 860 mm or less, the general shield excavator 2 can take in. For this reason, 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. It is also possible to change to a quadrant.

The components 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 an attachment position or temporarily fixing.
As shown in FIG. 4, the second pressure receiving plate 42 is a first detent that restricts lateral movement in the direction orthogonal to the tension axis O in the first pressure receiving plate 41 positioned on the tension side in the direction of the tension axis O. A member 44 is provided. Two first slip prevention members 44 are provided for each side of the outer peripheral edge of the first end face 42b of the second pressure receiving plate 42, and project toward the tension side in the direction of the tension axis O. In other words, 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 preventing members 44, and the lateral movement is restricted. Yes.

  Further, the laminated plate 43 is also provided with a second displacement preventing member 45 similar to the first displacement preventing member 44 of the second pressure receiving plate 42, and the second pressure receiving plate 42 extends in a direction perpendicular to the tension axis O. It is configured to restrict lateral movement. Two second slip preventing 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 direction of the tension axis O. That is, the second pressure receiving plate 42 is combined with the laminated plate 43, and the outer peripheral surface of the second pressure receiving plate 42 is pressed from the outside by the plurality of second displacement preventing members 45, so that the lateral movement is restricted.

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

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

  Thereafter, the fixing material (grout 16) is injected into the anchor fixing hole 31 in 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 distal end side of the anchor material 11 is fixed and fixed integrally with the fixing ground G in the anchor fixing hole 31 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, and the pressure receiving plate 4 and the support plate 17 are inserted into the outside of the tendon grip 12 in this order. And screwed into the threaded portion 12a on the outer peripheral surface of the outer peripheral surface.

Then, a 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 is fixed in a state where the protruding end 11a of the anchor material 11 and the tendon grip 12 are bonded together, and are integrated in a state in which they are in close contact by the frictional force due to the expansion pressure. Then, after a predetermined frictional force is obtained by the expansion and hardening of 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), and the anchor material 11 is pulled. A tension force is applied in the pulling direction to obtain a predetermined tension state, and the holding nut 13 is tightened to the cutting wall 3 side to maintain the tension state. Thereby, the pressure receiving plate 4 can be brought into pressure contact with the cutting wall 3.
Thereby, the cutting wall 3 can be reinforced by the plurality of anchor members 11, 11,..., And the cutting wall 3 is completed.

Thus, in this Embodiment, the pressure receiving part divided | segmented into the circumferential direction by the pressing nut 13 fastened by the tendon grip 12 fixed to the protrusion end 11a of the anchor material 11 of the state to which tension | tensile_strength was provided. 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, an anchor force can be transmitted from the pressure receiving plate 4 to the cutting wall 3, and the anchoring force is applied to the reinforcing anchor 1 to reinforce the cutting wall 3.
And in the cutting wall 3 comprised in this way, since it is reinforced with the some reinforcement anchor 1, it is suppressed that the cutting wall 3 bends to the inner side of the shaft 30 by earth 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 the operation thereof will be described in detail with reference to the drawings.
First, as shown in FIGS. 1 and 2, a start frame 32 on which the shield excavator 2 is placed is installed on the bottom of the shaft 30, and the cutter 21 is opposed to the cutting wall 3 on the start frame 32. The shield excavator 2 is installed in the state. And 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 propulsion reaction force 33 is provided on the reaction wall 33 installed at the position behind the shield excavator 2 and facing the cutting wall 3 in the vertical shaft 30 to start. . In the case of the shield excavator 2 having a structure that takes a reaction force laterally (in the radial 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 advanced 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 11 a side of the reinforcing anchor 1, the tightening force by the presser nut 13 is reduced and the friction resistance between the anchor material 11 and the tendon grip 12 is reduced. Also, the tensile force (tensile force) of the anchor material 11 is increased. Therefore, as shown in FIG. 10, the edges of the tendon grip 12 and the anchor material 11 are cut, and the fixed state of both is released, and the tendon grip 12 and the anchor material 11 are separated. Then, the pressure receiving plate 4 is not restrained when the anchor force (tension force) is released, 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). ) Is disassembled and falls into the chamber 22 of the shield excavator 2 (see FIG. 1). For example, when the length of the tendon grip 12 is 400 mm, when the half length of 200 mm is cut, the above-described action occurs, and the first pressure receiving plate 41 and the second pressure receiving pressure divided into a plurality of parts are obtained. The plate 42 and the laminated plate 43 fall off.
Next, after the plurality of divided pressure receiving plates 4 are dropped, 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 as shown in FIG. Drop out and drop out.

Thus, in this embodiment, since the pressure receiving plate 4 has a divided structure that is divided into a size that can be taken in by the shield excavator 2, it is possible to prevent the chamber 22 from being blocked, and to improve efficiency. The well-cut reinforcing anchor 1 can be taken into the shield excavator 2 and discharged.
In addition, in the present embodiment, the pressure receiving plate 4 has a simple structure in which the pressure receiving plate 4 is divided in the circumferential direction, and the other anchor configuration has the same configuration as a known one, so that there is an advantage that construction can be performed without an additional step. .

  In the present embodiment, since the pressure receiving plate 4 is divided into a plurality of directions in both the circumferential direction and the direction of the pulling axis O, the size of the pressure receiving plate 4 is further reduced when the pressure receiving plate 4 drops off from the protruding end 11a of the anchor material 11. Disassembled. Therefore, these decomposed pressure receiving plates 4 can be reliably taken in by the shield excavator 2, and blockage in the chamber 22 can be more reliably prevented.

  Further, in the present embodiment, the movement of the first pressure receiving plate 41 in the direction intersecting the direction of the tension axis O is restricted by the first displacement preventing member 44 provided on the second pressure receiving plate 42. In addition, the movement of the second pressure receiving plate 42 in the direction intersecting the direction of the pulling axis O is restricted by the second displacement preventing member 45 provided on the laminated plate 43. Therefore, in the state where the anchoring force is maintained by the reinforcing anchor 1, the pressure receiving plate 4 divided into a plurality in the circumferential direction combined by the presser nut 13 can enhance the integrity, and the cutting wall can be separated without separation. The restraint state with respect to the wall surface 3a of 3 can be maintained.

  In the present embodiment, the circumferentially divided surfaces 41d and 42d of the adjacent first pressure receiving plate 41 and second pressure receiving plate 42 divided in the direction of the tension axis O are shifted by 90 °, for example, in the circumferential direction. Thus, since the circumferentially divided surfaces 41d and 42d do not continue in the direction of the tension axis O, it is possible to suppress the pressure receiving plate 4 from being decomposed by an initial load during construction.

  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 part 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, the blockage in the chamber 22 can be reliably prevented.

  Moreover, in this Embodiment, the laminated board 43 has a division surface along the direction orthogonal to the side surface of a core material, and is divided | segmented into plurality, and each of the divided laminated plate 43 is orthogonal to the side surface of a core material. Therefore, the core member can be securely pressed by the pressure receiving plate 4.

  Further, in the present embodiment, a 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 expansion mortar 14 for fixing 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 fixing mortar 14 is injected between the two while the tendon grip 12 is fitted to the outside of the protruding end 11 a of the anchor material 11. It can be easily integrated by a predetermined frictional resistance.

As mentioned above, although embodiment of the reinforcement anchor by this invention was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it can change suitably.
For example, in the above-described embodiment, the start shaft is used as the target of the cutting wall 3, but it is also possible to use the reaching shaft as the target of the cutting wall.

  In the present embodiment, the pressure receiving plate 4 is divided into three parts along the tension axis O as the divided structure, 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 a configuration in which the division is not performed along the tension axis O direction may be employed. In short, the pressure receiving plate 4 only needs to be divided in the circumferential direction.

  Further, in the present embodiment, the displacement preventing members 44 and 45 for restricting the movement of the other pressure receiving plate in the direction intersecting the tension axis O direction to at least one adjacent pressure receiving plate divided in the direction of the tension axis O. However, it is possible to omit such displacement preventing 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 second pressure receiving plate 42 divided in the direction of the tension axis O, the circumferential division surfaces 41d and 42d divided in the circumferential direction are circumferentially separated. Although the configuration is shifted, the angle of the circumferential shift can be set as appropriate, and the configuration that does not have such a shift, that is, the circumferentially divided surfaces 41d and 42d are aligned with the direction of the pulling axis O. Also good.
Moreover, when the pressure receiving plate 4 is divided when being cut 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.

  Moreover, it is not limited to the structure which inject | pours the fixing expansion mortar (expandable solidification material) which expand | swells after hardening between the protrusion end 11a of the anchor material 11 and the cylindrical grip which consists of a tendon grip 12, and is only It is also possible to employ a solidified material that is bonded by curing.

  In addition, the constituent elements in the above-described embodiments can be appropriately replaced with known constituent elements without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Reinforcement anchor 2 Shield excavator 3 Cutting wall 4 Pressure receiving plate 11 Anchor material 12 Tendon grip (tubular grip)
13 Presser nut 14 Expansion mortar for fixing (expandable solidified material)
30 Vertical shaft 31 Anchor fixing hole 41 1st pressure receiving plate 42 2nd pressure receiving plate 43 Laminated plate 44, 45 Detachment member G Fixation ground O Pull shaft

Claims (7)

A reinforcing anchor that is fixed to the ground in a state where a predetermined tensile force is applied through a cutting wall that can be cut by a shield excavator, and can be cut by the shield excavator,
While fixing one end side of the tensile axis direction to the ground with a fixing material, the other end side protrudes from the cutting wall, and a tensile material having a threaded portion on the outer peripheral surface;
A pressure receiving plate fitted to the outside of the tension member;
A holding nut that is clamped to the threaded portion of the tension member and holds the pressure receiving plate in pressure contact with the cutting wall;
With
The said pressure receiving plate is divided | segmented into plurality in the circumferential direction which circulates around the tension axis | shaft of the said tension | pulling material, The reinforcement anchor characterized by the above-mentioned.   The reinforcing anchor according to claim 1, wherein the pressure receiving plate is divided into a plurality of portions in the direction of the tensile axis.   The at least one adjacent pressure receiving plate divided in the tension axis direction is provided with a displacement preventing member that restricts the movement of the other pressure receiving plate in the direction crossing the tension axis direction. The reinforcing anchor according to claim 2.   4. The reinforcement according to claim 2, wherein in the adjacent pressure receiving plates divided in the tensile axis direction, the respective circumferentially divided surfaces divided in the circumferential direction are displaced in the circumferential direction. 5. anchor.   The reinforcing anchor according to any one of claims 1 to 4, wherein the divided pressure receiving plate has a shape that can be taken into a machine from a chamber of the shield excavator. The cutting wall is provided with a core material that can be cut,
The pressure receiving plate has a laminated plate that contacts the side surface of the core member,
The reinforcing anchor according to any one of claims 1 to 5, wherein the laminated plate is divided into a plurality of parts having a dividing surface along a direction orthogonal to the side surface of the core member. . The tensile member is integrally fitted with an anchor member and a protruding end protruding from the cutting wall of the anchor member in a state where a frictional force exceeding the tensile force is applied, and has a threaded portion on the outer peripheral surface. A grip, and
The reinforcing anchor according to any one of claims 1 to 6, wherein an expandable solidified material that expands after being cured is injected between the protruding end of the anchor material and the cylindrical grip.

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