JP2019100177A - Shield start side shaft wall and construction method of shield start side shaft wall - Google Patents

Abstract

To drill effectively and securely by restricting a deflection of an anchor in drilling by a shield drilling machine in a drilling wall of a start side.SOLUTION: A shield start side shaft wall comprises: a drilling wall 3 arranged in a start area of a shield drilling machine 2 and capable of being drilled by the shield drilling machine 2; reinforcement anchors 1 anchored to a foundation in a condition where the drilling wall 3 is penetrated through and is imparted with a predetermined tension force by the anchor member 11; and a reinforcement wall 5 installed by a hardening material 5A to cover an exposed part of the reinforcement anchor 1 exposed at least on a wall surface 3a of the drilling wall 3. The reinforcement anchor 1 and the reinforcement wall 5 are formed of one or more materials capable of being drilled by the shield drilling machine 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a shield start side shaft wall and a method of constructing a shield start side shaft wall.

  Conventionally, as a shaft wall for shield drilling adopted when constructing an underground tunnel or a sewage main pipe by a shield construction method, for example, a composite material in which a hard urethane resin is reinforced with a long glass fiber, and a cutter of a shield drilling machine The cutting wall comprised by the member which can be cut by this is used.

Furthermore, as such a cutting wall for shield drilling, as shown, for example in patent documents 1, the construction method reinforced by the anchor which can be cut in a cutting wall is known.
In Patent Document 1, a cutting wall which can be cut by a shield excavating machine is penetrated and fixed to the ground in a state where a predetermined tensile force is applied by a tensile material, and can be cut by a shield excavating machine; Is described for a reinforced anchor having a pressure receiving plate that receives the pressure plate and presses it against the wall surface of the cutting wall.

JP, 2013-15006, A

  However, in the above-described structure in which the conventional cutting wall is reinforced with a cuttable anchor, depending on the cutting amount of the shield drilling machine and the rotational speed of the cutter when cutting the cutting wall on the launch side by the shield drilling machine, In particular, there is a possibility that fine cutting can not be performed because the pressure receiving plate and the anchor head, which are not restricted in their surroundings, move with the members shifted. Therefore, there is a problem that the pressure receiving plate and the member of the anchor head are taken into the shield excavating machine in the state of a large lump without being cut and the blockage occurs in the chamber or the mud pipe.

  Therefore, the present invention has been made in view of the above-mentioned problems, and in the cutting wall on the start side, it is possible to cut efficiently and reliably by suppressing the displacement of the anchor at the time of cutting by the shield excavating machine It is an object of the present invention to provide a method for constructing a shield start side shaft wall and a shield start side shaft wall.

  In order to achieve the above object, the shield-starting vertical shaft wall according to the present invention is provided in a starting region of a shield drilling machine and is made of a cutting wall which can be cut by the shield drilling machine and a cutting member penetrating the cutting wall. An anchor fixed to the ground with a tensile force applied, and a reinforcing wall driven by a hardening material so as to cover at least the exposed portion of the anchor exposed to the wall surface of the cutting wall, The anchor and the reinforcing wall may be formed of a material that can be cut by the shield drilling machine.

  Further, a construction method of the shield start side shaft wall according to the present invention is a construction method of the shield start side shaft wall for constructing the shield start side shaft wall described above, wherein Providing a cutting wall which can be cut by a shield excavating machine, fixing the anchor to the ground in a state where a predetermined tensile force is applied by a tension member penetrating the cutting wall, and at least a wall surface of the cutting wall Casting the hardened material with a mold so as to cover the exposed part of the anchor exposed to the above to form a reinforcing wall.

In the present invention, the periphery of the exposed portion of the anchor exposed from the wall surface of the cutting wall is covered with the hardened wall in which the hardened material is hardened. In this state, when cutting the reinforcing wall with the shield excavating machine, it is possible to suppress that the anchor head such as the pressure receiving plate and the like moves together with the rotation of the cutter.
Therefore, it is possible to cut with certainty by the shield drilling machine, and to reliably cut the anchor-reinforced shield pit wall.

  Further, in the shield-starting side shaft wall according to the present invention, the hardened material of the reinforcing wall is preferably cement-based fluidized-treated soil or mortar.

In this case, for example, a reinforced wall with a compressive strength of 0.1 N / mm ² or more can be constructed, whereby the periphery of the anchor head can be restrained at low cost and reliably.

  Moreover, the shield start side shaft wall concerning this invention may be provided with the connection reinforcement which connects the exposed parts of the said some anchors.

  In this case, by connecting the plurality of anchors to each other by the connection reinforcing material, the adhesion between the anchor and the reinforcing wall can be enhanced to achieve integration. Therefore, when the cutter of the shield drilling machine is pressed, it is possible to prevent the reinforcing wall from falling off from the cutting wall in the portion where the anchor is not disposed.

  Further, in the shield start side shaft wall according to the present invention, the connection reinforcement may be embedded in the reinforcing wall.

  In this case, the connection reinforcing member connecting the plurality of anchors and the reinforcing wall adhere to each other, and the adhesion between the anchor and the reinforcing wall can be further enhanced to achieve integration.

  Further, in the method of installing a shield start side shaft wall according to the present invention, the start area of the shaft wall is removed from the box, the cut wall is provided on the box removed wall removed from the box, and the formwork is removed from the opened surface. Preferably, the hardened material is cast in the box removing area after the

  In this case, since the reinforcing wall can be constructed in the area where a part of the shaft wall is removed from the box, the force applied to the reinforcing wall can be received by the shaft wall when cutting with the cutter of the shield drilling machine. The breakage of the reinforcing wall can be prevented, and it is possible to suppress that the anchor head such as the pressure receiving plate shifts together with the rotation of the cutter.

  Further, in the method of installing a shield start side shaft wall according to the present invention, the hardened material for forming the reinforcing wall may be divided into a plurality of stages in the vertical direction to be cast.

  In this case, since it is a method of placing a hardening material in stages, even in the case of a reinforcing wall having a large cross section, it is possible to place a mold without enlarging the formwork.

  According to the construction method of the shield start side shaft wall and shield start side shaft wall of the present invention, in the cutting wall on the start side, it is possible to cut efficiently and surely by suppressing the displacement of the anchor at the time of cutting by the shield excavator. can do. Therefore, the anchor can be finely cut, and it is possible to prevent the occurrence of blockage in the chamber of the shield drilling machine or in the mud pipe.

It is a side view showing a schematic structure of a shaft provided with a reinforcing wall according to an embodiment of the present invention. It is the figure which looked at the shaft shown in FIG. 1 from the upper direction. It is a front view of a cutting wall reinforced with a plurality of reinforcement anchors. It is a front view of the reinforcement anchor currently constructed by the cutting wall. It is the sectional view on the AA line shown in Drawing 4, and is the figure which fractured the reinforcement anchor currently constructed by the cutting wall seen from the upper part. FIG. 5 is a cross-sectional view taken along the line B-B shown in FIG. 4, which is a partially broken view of a reinforcing anchor applied to a cutting wall. It is CC sectional view shown in FIG. 4, and is a longitudinal cross-sectional view of the reinforcement anchor currently constructed by the cutting wall. (A)-(c) is a longitudinal cross-sectional view for demonstrating the construction procedure of a reinforcement wall. (A)-(c) is a longitudinal cross-sectional view for demonstrating the construction procedure of the reinforcement wall by a 1st modification. It is a partial front view of the cutting wall by the 2nd modification, and (a) is a figure in the state where only a transverse connection wire was attached, and (b) is a figure in the state where a vertical connection wire was attached. It is a front view which shows the state which wound the connection wire around the reinforcement anchor by 2nd modification. It is a DD line cross section arrow line view shown in FIG.

  Hereinafter, a method of installing a shield start side shaft wall and a shield start side shaft wall according to an embodiment of the present invention will be described in detail based on the drawings.

  As shown in FIG. 1 and FIG. 2, the shield start side shaft wall according to the present embodiment is the start portion of shield excavating machine 2 used in the shield tunnel excavation work in a shield start pit (hereinafter simply referred to as pit 30). And the cutting wall 3 is provided.

  The shaft 30 is provided in the start area of the shield excavating machine 2, and the cutting wall 3 which can be cut by the shield excavating machine 2 and the cutting wall 3 are penetrated and the ground G is applied in a state where a predetermined tensile force is applied by the anchor material 11. And a reinforcing wall 5 driven by a hardening material so as to cover at least the exposed portion of the reinforcing anchor 1 exposed to the wall 3a of the cutting wall 3. The reinforcing anchor 1 and the reinforcing wall 5 are formed of a material that can be cut by the shield drilling machine 2.

  The shaft 30 is constructed in the ground as a starting base of the shield drilling machine 2 and has a rectangular shape in top view, and a reinforced concrete wall is constructed on a digging surface dug down from the ground. The shaft 30 is constructed in such a size that it can be disposed with the shield drilling machine 2 directed in the digging direction, and can install equipment necessary for starting.

  The vertical shaft 30 is not limited to a rectangular shape in top view, and may be circular. Furthermore, the structure of the shaft 30 is not limited to the reinforced concrete structure, and a plurality of long H-shaped steels that are placed as earth retaining along the outer shell of the shaft 30 and between the H-shaped steels The wall may be a wall filled with concrete or mortar, or a concrete wall sunk with a caisson or the like.

  The shield excavating machine 2 has the cutter 21 face the cutting face, that is, the wall surface 3a of the cutting wall 3 on the starting frame 32 provided on the bottom plate of the shaft 30, and the central axis of the shield excavating machine 2 is the tunnel central axis It is arranged in the matched state.

  The cutting wall 3 is provided in a start region of the vertical shaft 30 constructed in the ground as a starting base of the shield drilling machine 2 and cut by the shield drilling machine 2. Specifically, the cutting wall 3 is cut by the cutter 21 of the shield drilling machine 2 with a circular cross section having a diameter larger than the outer diameter of the shield drilling machine 2.

For example, the SEW wall (a wall constructed by SEW (Shield Earth Retaining Wall System) method owned by Sekisui Chemical Co., Ltd.), an H-shaped steel, formed of a composite material in which a hard urethane resin is reinforced with long glass fibers. It is possible to adopt a shield starting and reaching earth retaining wall such as concrete reinforced with a type of FRP or carbon fiber.
Further, the cutting wall 3 is reinforced by a plurality of excavable anchors 1 made of a composite material in which a polyester resin is reinforced with long glass fibers and carbon fibers.

As shown in FIG. 3, in the cutting wall 3, a plurality of vertically extending cutting portion forming core materials (hereinafter, referred to as “cores 34”) are disposed at predetermined intervals in the horizontal direction, and the core 34 A cement hardening portion 35 made of only a soil cement hardened body is provided between the two members 34.
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 drilling machine 2, is reinforced with long glass fibers (though it is not particularly limited by the size of the ground or shaft of the construction site, H-shaped steel is obtained by fixing H-shaped steel on the upper and lower sides of 600x300 mm Sekisui Chemical Co., Ltd., Ethlon Neo Lumber FFU) through a joint, a bolt and a nut and the like.

Here, the cement hardened portion 35 put between the adjacent core member 34 and 34, the shear strength alone, and the compression strength for example shear strength 0.1 N / mm ^2, the compression strength 0.5 N / mm ² Since the pitch is low, by narrowing the pitch between the core members 34 and further increasing the size of the core member 34, it is possible to suppress the generated stress so that it can withstand shearing and compression due to side pressure. .

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 Anchor material 11 (tensile material) made to project from the wall 3 and the projecting end 11a of the anchor material 11 are integrally fitted with friction force exceeding tensile force and have a screw part 12a (see FIG. 7) on the outer peripheral surface The pressure receiving plate 4 which is fitted to the grip member 12 (tensile member) and the outside of the grip member 12 and press-contacts the wall surface 3 a of the cutting wall 3 and the screw portion 12 a of the grip member 12 And a holding nut 13 held in a state of being in pressure contact with the wall 3 side.
Here, the anchor member 11 and the grip member 12 constitute a tension member.

As shown in FIG. 1, the anchor material 11 functions as a tensile material consisting of a strand of carbon fibers that can be cut, and is an anchor fixing hole 31 (from the wall 3a side of the cutting wall 3 to the ground G on the back side) 7 (see FIG. 7), and the tip end portion (fixing end 11b) is fixed by the grout 16 filled in the anchor fixing hole 31 in the ground G. The anchor member 11 can apply a tensile tension to press against the wall surface 3 a of the cutting wall 3 via the pressure receiving plate 4 with a force to endure the earth pressure or water pressure. In addition, the anchor material 11 of this Embodiment is arrange | positioned toward diagonally downward from the inside of the vertical shaft 30. As shown in FIG.
Then, a portion of the anchor member 11 excluding the protruding end 11 a and the fixing end 11 b is inserted into the 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. 6 and 7, a so-called tendon grip can be used as the grip member 12, and the grip member 12 is integrally provided on the projecting end 11 a of the anchor member 11 via the fixing expansion mortar 14. The grip member 12 is formed of a material that can be cut, such as FRP, and is screwed to the outer peripheral surface so that the press nut 13 can be screwed. In a state where the pressure receiving plate 4 and the pressing nut 13 are mounted, a fixing expansion mortar 14 is injected between the grip member 12 and the projecting end 11 a of the anchor member 11 and is hardened in an expanded state. Since the fixing expansion mortar 14 expands as it hardens, the protruding end 11 a of the anchor member 11 and the grip member 12 are intimately brought into close contact with each other by the expansion thereof, and the grip member 12 is fixed to the pressure receiving plate 4 by the frictional force. In addition, the expansion mortar 14 for fixation can use the well-known thing used for a general anchor construction method.

  The holding nut 13 is made of a material that can be cut, such as FRP, and can be screwed to the screw portion 12 a of the outer peripheral surface of the grip member 12 as described above. By tightening the pressing nut 13, the pressure receiving plate 4 can be pressed against the wall surface 3 a of the cutting wall 3 in the direction of the tension axis O. That is, the pressure receiving plate 4 is held between the cutting wall 3 by tightening the holding nut 13.

  The pressure receiving plate 4 is formed of a cuttable material such as FRP, and includes a pressure receiving plate main body 40 and a laminated plate 41 interposed between the pressure receiving plate main body 40 and the cutting wall 3.

  As shown in FIG. 7, the pressure receiving plate main body 40 is provided with an insertion hole 40 a through which the grip member 12 can be inserted. The inner diameter of the insertion hole 40 a substantially matches the outer diameter of the grip member 12. In the pressure receiving plate main body 40, the first end surface 40b which contacts the wall surface 3a via the laminate plate 41 in the hole axial direction of the insertion hole 40a intersects the hole axial direction diagonally, and the second end surface 40c on the pressing nut 13 side Is a plane orthogonal to the hole axis direction. The first end surface 40 b and the second end surface 40 c are each formed in a rectangular shape as viewed from the direction orthogonal to the surface direction.

  The laminated plate 41 has a plate shape, and an insertion hole 41 a through which the grip member 12 can be inserted is formed at a central portion. With the laminated plate 41 fitted on the grip member 12, one first plate surface 41 b abuts on the first end face 40 b of the pressure receiving plate main body 40, and the other second plate surface 41 c is the wall surface 3 a of the cutting wall 3 It is provided so that it may contact | abut on the side of core material among them.

 As shown in FIGS. 1 to 3, the reinforcing wall 5 is formed in a circular shape in a front view seen from the tunnel axial direction so as to cover the wall surface 3 a of the cutting wall 3 and secures a predetermined wall thickness of the hardening material 5A. It has been set up. The reinforcing wall 5 has a head portion of the reinforcing anchor 1 (here, the head of the grip member 12 in which the surface 5a facing the inside of the shaft is exposed from the wall surface 3a of the cutting wall 3 as shown in FIGS. Section) is provided with a wall thickness to be embedded. In addition, as a covering thickness of the anchor head in the reinforcement wall 5, an anchor head is fully restrained by setting it as at least 5 cm, for example, and it is suitable for the cutting by the shield excavation machine 2. FIG.

As the hardened material 5A of the reinforcing wall 5, it is preferable to apply, for example, cement-based fluidized treated soil or mortar having a compressive strength of 0.1 N / mm ² or more. In this case, for example, a reinforced wall with a compressive strength of 0.2 N / mm ² or more can be constructed, whereby the periphery of the anchor head can be restrained at low cost and reliably. In addition, it is also possible to employ | adopt hardening resin, such as an epoxy and unsaturated polyester, as hardening material 5A of the reinforcement wall 5 elsewhere.

Next, a method of constructing the reinforcement anchor 1 and the reinforcement wall 5 on the cutting wall 3 will be described using the drawings.
First, as shown in FIG. 1 and FIG. 2, a vertical shaft 30 provided with a cutting wall 3 having a core material 34 and a cement hardening portion 35 is constructed in the start region of the shield drilling machine 2. Specifically, as shown in FIG. 8A, the core 34 is erected on the outer shell of the shaft 30, excavated inside, and the reinforced concrete shaft 30 is constructed inside the core 34. At this time, the box removing portion 33 is formed by removing the box from the start region of the shaft 30, and the cutting wall 3 is constructed on the back side of the box removing portion 33.
In addition, since the depth dimension of the box removing portion 33 corresponds to the wall thickness dimension of the reinforcing wall 5 shown in FIG. 7, the projecting length of the head of the reinforcing anchor 1 exposed from the wall surface 3 a of the cutting wall 3 is larger It needs to be set to

  Next, as shown in FIG. 1 and FIG. 2, the anchor fixing hole 31 of a predetermined length which penetrates the cutting wall 3 at a plurality of preset positions of the constructed cutting wall 3 and reaches the ground G is cut Drill holes using a drilling machine. Specifically, in the cement-hardened portion 35 between the core members 34 of the cutting wall 3 (see FIG. 3), drilling is performed, for example, at an inclination angle of 5 to 45 degrees downward using a drilling drill.

Then, as shown in FIG. 7, the tip end of the anchor member 11 to which the sheath tube 15 is partially attached reaches the tip end portion of the anchor fixing hole 31 and the projecting end 11 a of the anchor member 11 is a wall surface of the cutting wall 3 It is inserted into the anchor fixing hole 31 with a protruding length which protrudes from 3 a and secures the tightening length of the pressing nut 13. At this time, the sheath tube 15 is disposed so as to have a predetermined length from the cutting wall 3 toward the ground G side.
Thereafter, a 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 side of the anchor member 11 is integrally fixed with the ground G in the anchor fixing hole 31 as the grout 16 hardens, and is fixed.

  Next, the grip member 12 is fitted to the projecting end 11 a of the anchor member 11 from the outside, and further, the pressure receiving plate 4 and the pressure receiving plate 17 are inserted in this order on the outside of the grip member 12. The screw portion 12a of the outer peripheral surface of the screw is screwed.

Then, as shown in FIG. 7, the fixing expansion mortar 14 is injected and hardened between the grip member 12 and the protruding end 11 a of the anchor member 11. At this time, the fixing expansion mortar 14 expands, and the protruding end 11a of the anchor member 11 and the grip member 12 are fixed in a bonded state, 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 the expansion and hardening of the fixing expansion mortar 14, the anchor material 11 is pulled by gripping the portion of the grip member 12 which is projected from the holding nut 13 by a jack-up device (not shown). The tension is applied in the pulling direction to bring it into a predetermined tension state, and the holding nut 13 is tightened to the cutting wall 3 side to hold the tension state. Thus, the pressure receiving plate 4 can be pressed against the cutting wall 3.
As a result, the cutting wall 3 can be reinforced by the plurality of anchor members 11, 11,... And the cutting wall 3 is completed.

As described above, in the present embodiment, the pressure receiving plate 4 is a wall surface of the cutting wall 3 by the pressing nut 13 which is tightened to the grip member 12 fixed to the protruding end 11 a of the anchor member 11 in the tension applied state. It is pressed against 3a and restrained. Thereby, the anchor force can be transmitted to the cutting wall 3 from the pressure receiving plate 4, 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 by the some reinforcement anchor 1, it is suppressed that the cutting wall 3 is bent inside the vertical shaft 30 by earth pressure.

Next, as shown in FIGS. 8A to 8C, the hardened material 5A is cast using the mold 6 so that the exposed portion of the reinforcing anchor 1 exposed to the wall surface 3a of the cutting wall 3 is covered. The reinforcing wall 5 is formed.
First, as shown in FIGS. 8A and 8B, the mold 6 supported by the support 61 is installed on the entire surface of the opening of the box removing portion 33. Next, as shown in FIG. 8C, the hardened material 5A is placed and hardened in the area of the box removing portion 33. The formwork 6 is provided in advance with a pouring opening that can be opened and closed.

When the casted material 5A is sufficiently cured, the form 6 is removed. Although it is necessary to remove the formwork 6 when the formwork 6 is a difficult-to-cut material made of metal, the shield shown in FIG. 1 is not removed when the formwork 6 is an easily-cuttable material such as resin, FRP, or wood. It is also possible to cut with the excavator 2.
In this manner, the reinforcing wall 5 in which the periphery of the head of the reinforcing anchor 1 is covered with the hardening material 5A is constructed in the box-unloading portion 33.

Next, the operation of the method for installing the shield start side shaft wall and the shield start side shaft wall of the above-described configuration will be described in detail with reference to the drawings.
As shown in FIG. 7, in the present embodiment, the periphery of the exposed portion of the reinforcing anchor 1 exposed from the wall surface 3a of the cutting wall 3 is covered by the reinforcing wall 5 in which the hardening material 5A is hardened. In this state, when cutting the reinforcing wall 5 with the shield excavating machine 2 shown in FIG. 1, it is possible to suppress that the anchor head such as the pressure receiving plate 4 shifts with the rotation of the cutter. That is, the shift | offset | difference of the anchor head and the pressure receiving plate 4 at the time of cutting by the shield excavator 2 can be suppressed.
Therefore, the shield drilling machine 2 can reliably cut finely, and the anchor-reinforced shield pit wall can be reliably cut.

  Further, in the present embodiment, since the reinforcing wall 5 can be constructed in a region where a part of the shaft 30 is cut out, the force applied to the reinforcing wall 5 when cutting with the cutter of the shield drilling machine 2 can be Therefore, the reinforcement wall 5 can be prevented from being broken, and it is possible to suppress that the anchor head such as the pressure receiving plate shifts as a whole and moves with the rotation of the cutter.

  As described above, in the method of installing the shield start side shaft wall and the shield start side shaft wall according to the present embodiment, in the cutting wall 3 on the start side, the displacement of the anchor at the time of cutting by the shield excavator 2 is suppressed. It is possible to cut efficiently and reliably. Therefore, the anchor can be cut finely, and it is possible to prevent the occurrence of blockage in the chamber of the shield drilling machine 2 or in the mud pipe.

(First modification)
Next, the construction method of the shield start side shaft wall by a 1st modification is demonstrated.
For example, in the embodiment described above, although the mold is used at one time using the form 6, for example, as shown in FIGS. 9A to 9C, the form 6A divided into a plurality of stages is The hardening material 5A used to form the reinforcing wall 5 may be divided into a plurality of steps (two upper and lower steps in FIG. 9) in the upper and lower direction. That is, as shown in FIG. 9A, first, the lowermost mold 6A is installed at the box removing portion 33, and as shown in FIG. 9B, the reinforcing material 5A is cast to form the reinforcing wall 5. Do. Next, as shown in FIG. 9C, after the mold frame 6A is installed on the lowermost reinforcing wall 5 placed in the box removing portion 33, the hardening material 5A is cast to form the reinforcing wall 5 Do. In this case, since it is a method of placing the hardening material 5A in stages, even in the case of the reinforcing wall 5 having a large cross section, the formwork can be placed without increasing the size.

(2nd modification)
Next, as shown in FIGS. 10 (a), (b), FIG. 11 and FIG. 12, the shield start side shaft wall according to the second modification is an anchor head of a plurality of reinforcing anchors 1, 1,. The parts (exposed parts) are connected by the connection wire 7 (connection reinforcing material) to achieve integration.
Specifically, horizontal connection wires 7A connecting reinforcement anchors 1, 1,... Arranged in the horizontal direction, and longitudinal connection wires 7B connecting reinforcement anchors 1, 1,. ,have. The connection wires 7A and 7B are wound around the pressing nut 13 and the grip member 12 of a portion of the reinforcement anchor 1 that protrudes obliquely upward from the pressure receiving plate 4.

And one connection wire 7A, 7B is sequentially wound around the adjacent reinforcement anchors 1 arranged in the vertical and horizontal directions, respectively. That is, as shown to Fig.10 (a), the vertical connection wire 7B is attached to the upper side to which 7 A of horizontal connection wires were attached, as shown in FIG.10 (b).
The horizontal connection wire 7A may be attached to the upper side of the vertical connection wire 7B. By connecting the plurality of reinforcing anchors 1 and 1 to each other by the connecting wire 7 in this manner, the connecting wire 7 and the reinforcing wall 5 adhere to each other, and the adhesion between the reinforcing anchor 1 and the reinforcing wall 5 is enhanced to integrate them. Can be

As shown in FIG. 11, the end portion 7 a of the connection wire 7 is formed in a ring shape and is locked to a suspension bolt 43 fixed to the side surface 4 a of the pressure receiving plate 4. Similarly to the pressure receiving plate 4, a bolt made of FRP resin that can be cut by the cutter 21 (see FIGS. 1 and 2) of the shield drilling machine 2 described above is adopted as the suspension bolt 43. In addition, it is not limited to the suspension bolt 43, Another locking member may be sufficient, and the attachment position of the suspension bolt 43 is not limited to being the side surface 4a of the pressure receiving plate 4, either.
Furthermore, since the connection wire 7 may be connected to the reinforcement anchor 1, the end 7a of the connection wire 7 may not be fixed.

As the connection wire 7, a member that can be cut by the cutter 21 of the shield drilling machine 2 is provided, and for example, a CFRP wire (product name "CFCC") manufactured by Tokyo Seisen Co., Ltd. can be used. In particular, in order to enhance adhesion of the connection wire 7 with the fluidization treated soil and soil cement in the reinforcing wall 5, it is preferable that the connection wire 7 has a strand specification as shown in FIGS. 11 and 12.
The locking position of the connection wire 7 in the reinforcing anchor 1 is not limited to the anchor head, and may be an exposed member that protrudes from the cutting wall 3 in the reinforcing anchor 1, for example, a pressure receiving plate 4 (exposed member). It does not matter.

  As a construction method according to the second modification, as shown in FIGS. 8 (a) and 9 (a), a mold for driving the hardened material 5A of the reinforcing wall 5 after the reinforcement anchor 1 is driven. Before installation of the frames 6 and 6A, the connecting wire 7 is wound around and attached to the anchor heads of the reinforcement anchors 1 as shown in FIGS. Thereafter, the formwork 6, 6A is installed, and the hardening material 5A is cast to form the reinforcing wall 5.

In the second modification, as shown in FIGS. 10 (a) and 10 (b), since the reinforcement anchor 1 is placed in the cement-hardened portion 35 between the core members 34, 34, the reinforcement anchors 1 are By connecting, it is possible to integrate the core 34 and the cement-hardened portion 35 and to improve the yield strength. Therefore, as in the second modification, the core material 34 is continuously disposed in a state in which low strength mortar such as fluidized treated soil or soil cement is placed on the surface of the cutting wall 3 to improve machinability. Even when the cutter 21 (see FIGS. 1 and 2) of the shield excavating machine 2 is pressed against the cutting wall 3, the portion from which the anchor head is not disposed is reinforced from the cutting wall 3 It is possible to prevent the wall 5 from peeling off.
In addition, in the 2nd modification, it is not limited to the structure which makes the connection wire 7 lock with respect to all the reinforcement anchors 1, You may have the reinforcement anchor 1 which does not make the connection wire 7 lock.

  As mentioned above, although the embodiment of the construction method of the shield start side shaft wall and the shield start side shaft wall by this invention was described, this invention is not limited to said embodiment, The range which does not deviate from the meaning Can be changed as appropriate.

  Also, the shaft on which the shield start side shaft is provided is not limited to the start shaft as in the present embodiment, for example, the direction of the shield excavating machine is rotated by the reaching shaft or rotating shaft. It is also possible to apply the shield-starting vertical shaft to the re-starting side when re-starting.

  Moreover, in the 2nd modification mentioned above, although the connection wire 7 is employ | adopted as a connection reinforcement material, it is not limited to being a wire, It is also possible to use another member. For example, the structure which connects exposed parts, such as the anchor head of reinforcement anchor 1, with the rod member which can be cut off may be used. In particular, in order to increase the adhesion strength of the reinforcing wall with the hardened material, it is preferable that the connection reinforcing material has irregularities formed on the surface.

  Furthermore, the connection object of the reinforcement anchor 1 can be set arbitrarily. That is, it is not limited to winding and connecting reinforcement anchors 1 and 1 arranged in each of the vertical and horizontal directions as in the second modification, for example, reinforcement anchors 1 arranged diagonally, 1 may be connected with each other.

  Further, in the second modification described above, the connection wire 7 (connection reinforcement) is embedded in the reinforcing wall 5, but is limited to being embedded in the reinforcing wall 5. Alternatively, the connection reinforcement may be provided exposed.

  Moreover, it is possible to replace the component in the above-mentioned embodiment with a well-known component suitably in the range which does not deviate from the meaning of this invention.

1 Reinforcement anchor (Anchor)
Reference Signs List 2 shield drilling machine 3 cutting wall 3a wall surface 4 pressure receiving plate 5 reinforcing wall 5A hardened material 5a surface 6, 6A formwork 7 connecting wire (connection reinforcing material)
7A Horizontal connection wire 7B Longitudinal connection wire 11 Anchor material 12 Grip member 13 Press-fit nut 14 Expansion mortar for fixation 30 Vertical shaft 31 Anchor fixing hole 40 Pressure receiving plate body 41 Laminated plate G Ground O Tension axis

Claims (7)

A cutting wall provided in the start area of the shield excavator and cuttable by the shield excavator;
An anchor which is fixed to the ground in a state where a predetermined tensile force is applied by a tensile member by penetrating the cutting wall;
A reinforcing wall driven by a hardening material so as to cover at least an exposed portion of the anchor exposed to a wall surface of the cutting wall;
Equipped with
A shield launch side shaft wall characterized in that the anchor and the reinforcing wall are made of a material that can be cut by the shield drilling machine.   The shield-start shaft wall according to claim 1, wherein the hardened material of the reinforcing wall is cement-based fluidized-treated soil or mortar.   The shield start side shaft wall according to claim 1 or 2, further comprising a connection reinforcing member connecting the exposed portions of the plurality of anchors.   The shield start side shaft wall according to claim 3, wherein the connection reinforcement is embedded in the reinforcing wall. A construction method of a shield start side shaft wall for constructing a shield start side shaft wall according to any one of claims 1 to 4, comprising:
Providing a cutting wall which can be cut by the shield drilling machine in a start area of the shield drilling machine;
Fixing the anchor to the ground in a state in which the cutting wall is penetrated and a predetermined tensile force is applied by a tensile material;
Casting a hardening material using a mold so as to cover at least the exposed portion of the anchor exposed to the wall surface of the cutting wall to form a reinforcing wall;
A method of constructing a shield start side shaft wall characterized by having: The start area of the shaft wall is removed from the box, and the cut wall is provided on the removed wall of the box,
The method for applying a shield start side shaft wall according to claim 5, wherein the hardened material is placed in a box removing area after the formwork is provided on the box removed opening face.   The method for applying a shield start side shaft wall according to claim 5 or 6, wherein the hardened material for forming the reinforcing wall is divided into a plurality of stages in the vertical direction and cast.

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