JP6429973B1 - How to dig a sliding back anchor and shield machine - Google Patents

Abstract

An object of the present invention is to provide a means that does not require a new jack for moving or positioning a sliding back anchor.
A back anchor A including at least a plurality of anchor beams 10 connected to a shield jack Y, and a position adjusting unit B (a screw rod 30 and a support column 40 interposed between the anchor beam 10 and a fixed point C). , A sliding back anchor having at least a restricting tool 50). During expansion / contraction work of the shield jack Y, the digging thrust or earth pressure received by each anchor girder 10 is transmitted to the fixed point C in the order of the restricting tool 50, the screw rod 30, and the bearing column 40. In the moved anchor girder 10, the remaining restriction tool 50 is returned to its original position, and is used as a reaction force receiver when the other anchor girder 10 is moved.
[Selection] Figure 1

Description

  The present invention relates to a slide-type back anchor used for initial excavation of a shield machine and a shield machine excavation method using the slide-type back anchor.

  Techniques described in the following prior art documents are known as methods for receiving a reaction force accompanying the advance of the shield machine during the initial excavation of the shield machine.

JP 2012-41748 A JP 2013-133682 A

Sato Kogyo Co., Ltd. “Center Hall Jack Method Shield Start Method” http://www.satokogyo.co.jp/technology/detail.php?id=23&parent_id=2&category_id=23

  In the slide type back anchor described in these documents, a jack other than the shield jack must be newly provided for the movement of the back anchor to receive the reaction force of the shield jack, and it takes time to install these jacks. And the problem that the work space is occupied has arisen.

  Therefore, an object of the present invention is to provide a means that does not require a new jack for moving or positioning the sliding back anchor.

The first invention of the present application to solve the above problems is a sliding back anchor used for excavation of a shield machine, and includes at least a plurality of anchor beams connected directly or indirectly to a shield jack of the shield machine. Comprising at least a back anchor and a position adjusting unit interposed between the anchor girder and a fixed point so as to be capable of positioning the anchor girder with respect to a digging direction of a shield machine. The girder has at least an insertion hole penetrating in the digging direction and communicating with each other, and the position adjusting unit is inserted into the insertion hole with the digging direction as a longitudinal direction, and a screw rod and the digging direction in the longitudinal direction At least a support column and a restricting tool that can be screwed into the threaded rod to restrict the backward movement of the anchor beam from the threaded position. The columns are connected directly or indirectly to the front end sides of each other, the rear end side of the screw rod is released, and the rear end side of the bearing column is connected to the fixed point, and the anchor beam The digging thrust or earth pressure received by is transmitted in the order of a restricting tool, a screw rod, a supporting column, and a fixed point.
Further, in the second invention of the present application, in the first invention, at least any one anchor girder other than the movement target supports the anchor girder to be moved regardless of the expansion / contraction state of the shield jack. And a support surface.
According to the third invention of the present application, in the first invention or the second invention, the anchor beam and the screw rod are shared by the anchor beams.
According to a fourth invention of the present application, in any one of the first to third inventions, a transmission beam connected to a rear end of a shield jack is provided in front of the anchor beam. And
According to a fifth aspect of the present invention, there is provided a shield machine excavation method using the sliding back anchor according to any one of the first to fourth aspects, wherein: (a) a plurality of anchor beams (B) a step of extending a shield machine by extending a shield jack connected to at least one of the plurality of anchor beams, and (c) a moving object. (D) Inserting the anchor girder to be moved forward while reducing the length of the shield jack connected to the anchor girder, and receiving the earth pressure at the anchor girder other than the object to be moved, (d) It includes at least a step of advancing screwing of a restricting tool on a certain screw rod to the state of (a).

According to the present invention, at least one of the effects described below is achieved.
(1) Since the anchor girder (back anchor) to which the shield jack is connected is positioned with a restricting tool screwed onto the screw rod, a jack other than the shield jack (such as a center hole jack) is not required.
Therefore, the installation time of the jack and the hydraulic mechanism can be reduced and the work space can be secured.
(2) Construction of a temporary segment is unnecessary.
(3) According to the above (1) and (2), shield excavation in a narrow shaft is possible.
(4) Since the shield jack is originally configured to be operable independently, the direction control during the initial excavation is also easy.
(5) By sharing the bearing column and the screw rod between the anchor beams, it is possible to secure more space around the back anchor.
(6) Since the anchor beam is always supported by other anchor beams, the anchor beam can be supported stably.

1 is a schematic side view showing an overall configuration of a sliding back anchor according to Embodiment 1. FIG. The schematic front view which shows the structure of a back anchor. The schematic sectional drawing which shows the positional relationship of an anchor girder, a screw rod, and a support column. Schematic (1) which shows the procedure of the excavation method of a shield machine. Schematic (2) which shows the procedure of the excavation method of a shield machine. Schematic which shows the structure of a back anchor in the slide type back anchor which concerns on Example 2. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<1> Overall configuration (Fig. 1)
FIG. 1 shows an example in which the slide-type back anchor according to the present invention is used when the shield machine is initially excavated from the starting vertical shaft.
The sliding back anchor is a structure that is installed behind the shield machine X.
The sliding back anchor includes at least a back anchor A that is directly or indirectly connected to the shield jack Y, and a position adjusting unit B that adjusts the position of the back anchor A.
The back anchor A includes at least a plurality of anchor beams 10 that directly or indirectly connect the shield machine X with the excavation thrust of the shield machine X and the earth pressure received by the shield machine X.
Further, the position adjusting unit B includes at least a screw rod 30, a supporting column 40, and a restricting tool 50 for configuring the anchor beam 10 so as to be individually movable and positionable.
Details of each component will be described below.

<2> Anchor girder (FIGS. 1 to 3)
The anchor girder 10 is a member for directly or indirectly receiving the excavation thrust by the shield machine X and the earth pressure received by the shield machine X when the shield jack Y is expanded and contracted.
The anchor girder 10 is formed by dividing the back anchor into groups of shield jacks, and the anchor girder 10 can be moved individually by individually operating the shield jacks Y connected to the anchor girders 10.
In this embodiment, as shown in FIG. 2, the back anchor A is divided into four anchor girders (upper anchor girder 10a, lower anchor girder 10b, and two lateral anchors) obtained by dividing a rectangular girder on each side. Digits 10c and 10d).

<2.1> Installation of transmission girder (Figs. 1 and 2)
In this embodiment, as shown in FIGS. 1 and 2, transmission girders 20 (20 a to 20 d) are provided on the front side of the anchor girders 10, and the rear ends of the shield jacks Y are connected to the respective transmission girders 20. ing.
Therefore, each anchor girder 10 in the present embodiment has a structure that indirectly receives the digging thrust or the like of the shield machine X via each transmission girder 20.

<2.2> Formation of insertion holes (Figs. 2 and 3)
Each anchor girder 10 (10a to 10d) is provided with an insertion hole 11 (11a to 11d) that penetrates in the front-rear direction (digging direction).
As shown in FIG. 2, two insertion holes 11 are provided at both ends in the longitudinal direction of each anchor beam 10 with a space in the vertical direction.
The diameter of the insertion hole 11 is larger than a screw rod 30 described later.
Therefore, in this embodiment, two places are provided at each longitudinal end of one anchor girder 10, and one anchor girder 10 has a total of four insertion holes 11.

<2.3> Formation of through holes (Figs. 2 and 3)
In addition, each anchor beam 10 (10a to 10d) is provided with one through hole 12 (12a to 12d) that extends through the insertion hole 11 in the front-rear direction (digging direction).
The diameter of the insertion hole 12 is larger than a screw rod 30 described later.
Therefore, in this embodiment, one anchor girder 10 has a total of two through holes 12 at one end in the longitudinal direction.

<3> Screw rod (Figs. 1 and 3)
The screw rod 30 is an element for transmitting the digging thrust and the like of the shield machine X to the support column 40 via a restricting tool 50 described later.
The screw rod 30 (30a to 30d) is formed of a member having a screw groove whose longitudinal direction is the digging direction, and for example, a PC steel rod can be used.
As shown in FIG. 1, the front end side of the screw rod 30 is fastened to a nut (not shown) fixed to a connection plate 31 provided separately, and the rear end side of the screw rod 30 is a release end. It is said.
The connection plate 31 may be placed or suspended by a member (not shown) and prevented from falling.
As shown in FIG. 3, the screw rods 30 are respectively inserted into the insertion holes 11 provided at both ends of the anchor beam 10.

<4> Bearing column (Figs. 1 and 3)
The supporting column 40 is an element for connecting the screw rod 30 and the fixed point C and transmitting the digging thrust and the like of the shield machine X to the fixed point C.
The bearing column 40 (40a to 40d) is formed of a column member whose longitudinal direction is the digging direction.
As shown in FIG. 1, the front end side of the support column 40 is connected to the connecting plate 31 to which the front end side of the screw rod 30 is fixed, and the rear end side of the support column 40 is connected to the shaft. The fixed point C is fixed.
As shown in FIG. 3, the support column 40 is inserted through the through holes 12 provided at both ends of the anchor beam 10.

<5> Regulator (Fig. 3)
The restricting tool 50 is a member for restricting the backward movement of the anchor beam 10 inserted through the screw rod 30 by being screwed into the screw rod 30.
As shown in FIG. 3, the restrictor 50 (50 a to 50 d) can be screwed into the screw rod 30, and a nut having a larger diameter than the insertion hole 11 can be used.
If the restricting tool 50 is screwed from the open end side of the screw rod 30 and is held at a position near the back of the anchor girder 10, the restricting tool 50 interferes with the anchor girder 10 even if the anchor girder 10 tries to retreat. As a result, the anchor girder 10 cannot move rearward from the screwing position of the restriction tool 50.

<6> Procedure when the shield machine goes straight (Figs. 4 and 5)
In the shield machine excavation method using the sliding back anchor described above, an example of a procedure when the shield machine X goes straight will be described.
4 and 5, illustration of the shield jack Y, the anchor beam 10, the transmission beam 20, and the like that are visible on the back side may be omitted for convenience of explanation.

<6.1> Step (a): Initial State (Backward Restricted State) (FIG. 4 (a))
In Fig.4 (a), it is in the state in which the control tool 50 (50a-50d) is screwed behind all the anchor girders 10 (10a-10d), and the retreat of the back anchor A is controlled. is there.

<6.2> Step (b): Advance of shield machine (FIG. 4B)
When the extension of all the shield jacks Y is started from this state, the shield machine X digs in the straight direction.
At this time, the digging thrust of the shield machine X generated along with the extension of each shield jack Y is generated from each anchor girder 10, the restricting tool 50 provided behind the anchor girder 10, the screw rod 30, the bearing column 40, and the immobility. It is transmitted in the order of point C.
Therefore, the excavation thrust of the shield machine X is finally transmitted to the fixed point C, and the back anchor A functions as a reaction force receiving portion.

<6.3> Step (c): Pulling the anchor beam (FIG. 4C)
From the state where all the shield jacks Y are extended, the length reduction work of the shield jack Y of each anchor girder 10 is performed, and the anchor girder Y is drawn (advanced) individually.
This is because if all the anchor beams 10 are pulled at the same time, the earth pressure received by the shield machine X cannot be received and buckling of the shield machine X occurs.
The attracting anchor digit 10 is defined as an anchor digit to be moved, and the other anchor digits 10 are defined as anchor digits other than the movement target.

[Pulling side anchor girder]
FIG.4 (c) has shown the state which pulled the horizontal anchor girder 10c in the front side among the four anchor girders (10a-10d).
At this time, the remaining three anchor girders (upper anchor girder 10a, lower anchor girder 10b, and lateral anchor girder 10d) are still in the same position, and each restricting tool 50 (50a, 50b, 50d). Is a state in which the backward movement is restricted.
Therefore, the earth pressure received by the shield machine during the pulling work of the anchor girder for movement (lateral anchor girder 10c) is the anchor girder other than the movement object (upper anchor girder 10a, lower anchor girder 10b, horizontal anchor girder 10d). In response, the restrictors 50 (50a, 50b, 50d), the screw rods 30 (30a, 30b, 30d), the bearing columns 40 (40a, 40b, 40d), which are provided behind the anchor beams 10, are immobile. It is transmitted and received in the order of point C.

[Separation between side anchor girder and restrictor]
Further, the restricting tool 50c screwed into the threaded rod 30c inserted through the pulled lateral anchor girder 10c is left in the same position.

<6.4> Step (d): Advancement of Regulator (FIG. 5 (a))
As described above, the restricting tool 50c screwed into the threaded rod 30c inserted through the pulled lateral anchor girder 10c is left in the same position, and the retraction of the horizontal anchor girder 10c is restricted as it is. It is a state that has not been done.
Therefore, the restriction member 50c left behind the lateral anchor beam 10c is screwed on the screw rod 30c, and the restriction member 50c is moved to the back of the lateral anchor beam 10c again.
If it will be in this state, it can return to the state which can transmit the force which the side anchor girder 10c receives to the control tool 50c.

<6.5> Repeat to remaining anchor girder (Fig. 5 (b))
For the remaining upper anchor beam 10a, lower anchor beam 10b, and lateral anchor beam 10d, if all the anchor beams 10 (10a to 10d) are finally advanced by proceeding the above steps (c) and (d), The steps (a) and (b) can be advanced toward the next excavation work by the shield X.

<7> Procedures for turning the shield machine (not shown)
Although not shown, when bending the shield machine X in any direction, the direction can be adjusted by extending or shortening the shield jack Y for the anchor beam 10 in the appropriate bending direction. It is.

<8> Others (support structure for side anchor girders)
In FIG. 4C, for convenience of explanation, the extension length of the shield jack Y is increased, and the lateral anchor beam 10c and the other anchor beam 10 (10a, 10b, 10d) are separated from each other. The anchor girders are configured to be supported by rail members (not shown). For example, if the expansion / contraction length of the shield jack Y is shorter than the front and rear width of each anchor girder 10 (not shown), the lower anchor The upper surface of the girder 10b can have a support surface that always supports the pulled lateral anchor girder 10c.
Similarly, if the lateral anchor girders 10c and 10d have a support surface for supporting the upper anchor girders 10a, the anchor girders 10 are unstable regardless of the order in which the anchor girders 10 are pulled. Will not be placed in position.

<9> Summary As described above, according to the slide type back anchor according to the present invention, since the shield jack is used for the excavation of the shield machine and the movement of the back anchor, no additional equipment such as a jack or a temporary segment is required.
Moreover, since the installation space of these additional facilities is released, it is useful at the time of initial excavation in a narrow shaft.

  A second embodiment of the present invention will be described with reference to FIG.

<1> Sharing of screw rod and bearing column (Fig. 6)
In the present invention, the anchor bar 10 may be configured to share the screw rod 30 and the bearing column 40 with each other.
FIG. 6 shows a structure around the anchor beam 10 of the sliding back anchor A according to the second embodiment.
In FIG. 6, each anchor beam 10 is arranged so that these insertion holes 11 are overlapped with the upper anchor beam 10 a and the lower anchor beam 10 b as the front side and the lateral anchor beams 10 c and 10 d as the rear side. Yes.
Then, the screw rod 30 and the support column 40 are inserted through the overlapping insertion holes 11, and the screw rod and the support column are shared at the four corners of the entire back anchor.
At this time, when the front anchor beam 10a, 10b and the rear anchor beam 10c, 10d are brought into contact with each other, the rear anchor beam regulators 50a, 50b are prevented from interfering with each other. A part of the diameter of the insertion holes 11c, 11d may be made larger than the diameter of the restricting tool.
In the embodiment, the pulling operation of the anchor beam 10 by the contraction of the shield jack Y is performed by moving the anchor beams 10a and 10b on the front side first and then moving the anchor beams 10c and 10d on the rear side thereafter. It is necessary to proceed.

<2> Support of Anchor Girder In addition, in this embodiment, the anchor girder 10a, 10b and the anchor girder 10c, 10d have a front-rear relationship, so the upper anchor girder 10a is connected to both lateral anchor girders 10c, 10d. Support surfaces 13c and 13d that can be supported regardless of movement are provided. (Reference numeral 13d is not shown)
Therefore, the upper anchor beam 10a can be supported by the lateral anchor beams 10c and 10d when the upper anchor beam 10a is pulled.
Similarly, if the lower anchor beam 10b is provided with a support surface 13b for supporting the horizontal anchor beams 10c and 10d, the lower anchor beam 10c and 10d can be moved to the lower anchor beam 10c and 10d. These anchor beams 10c and 10d can be supported by the anchor beam 10b.

<3> Summary As described above, according to the sliding back anchor according to the present embodiment, by sharing the screw rod and the supporting column, it is possible to reduce these points and to secure more space around the back anchor. Is obtained.

A Back anchor 10 Anchor girder 11 Insertion hole 12 Through hole 13 Support surface 20 Transmission girder B Position adjustment part 30 Screw rod 31 Connection plate 40 Bearing column 50 Regulator X Shield machine Y Shield jack C Fixed point

Claims (5)

It is a sliding back anchor used for digging a shield machine,
A back anchor comprising at least a plurality of anchor beams connected directly or indirectly to a shield jack of a shield machine;
A position adjusting unit interposed between the anchor beam and the fixed point, and configured to position the anchor beam freely with respect to a digging direction of a shield machine,
The anchor beam is
Having at least an insertion hole that penetrates in the digging direction and communicates with each other,
The position adjusting unit is
A threaded rod inserted through the insertion hole, with the direction of digging as the longitudinal direction,
A bearing column whose longitudinal direction is the digging direction;
A screw that is screwed into the screw rod, and is capable of restricting the backward movement of the anchor beam backward from the screwing position.
The screw rod and the supporting column connect the front end sides of each other directly or indirectly,
The rear end side of the screw rod is released,
The rear end side of the bearing column is connected to the fixed point,
The excavation thrust or earth pressure received by the anchor girder is transmitted in the order of a restriction tool, a screw rod, a supporting column, and a fixed point,
Sliding back anchor. In at least any one anchor girder other than the moving object, it has a support surface that supports the anchor girder of the moving object regardless of the expansion / contraction state of the shield jack,
The sliding back anchor according to claim 1. The anchor girders share a bearing column and a screw rod,
The sliding back anchor according to claim 1 or 2. In front of the anchor beam, a transmission beam connected to the rear end of the shield jack is provided,
The slide type back anchor according to any one of claims 1 to 3. A method for digging a shield machine using the sliding back anchor according to any one of claims 1 to 4,
(A) a step of restricting the retreat of the plurality of anchor beams with a restricting tool;
(B) extending the shield jack connected to at least one of the plurality of anchor beams to advance the shield machine;
(C) a step of contracting the shield jack connected to the anchor girder to be moved and drawing the anchor girder to be moved forward while receiving earth pressure with the anchor girder other than the moving girder;
(D) a step of advancing screwing of the restricting tool on the screw rod inserted through the anchor girder to be moved back to the state of (a);
Including at least
How to dig shield machines.

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