JP6452474B2 - Support structure of tunnel lining concrete formwork - Google Patents

Description

The present invention relates to a support structure for a tunnel lining concrete formwork.

As tunnel formation techniques, there are a NATM (New Austrian Tunneling Method) method and a sheet pile method. Currently, the NATM method is widely used.

For example, Patent Document 1 discloses a configuration using a plurality of teleforms that can be reduced in diameter in an excavation hole in order to construct a lining body in the NATM method. The teleform is placed along the inner peripheral surface of the tunnel in the unfolded state, and concrete forming a covering body is placed in the gap between the formwork device and the excavation hole. The teleform supports the concrete until a predetermined strength develops for the placed concrete. And after predetermined intensity | strength expresses about concrete, a teleform is diameter-reduced and it sends in the excavation direction front in a tunnel. The teleform sent forward is unfolded again and supports the concrete while it is being placed. A plurality of such teleforms are connected in the tunnel excavation direction, and the teleforms that have finished supporting concrete are sequentially sent forward to speed up the construction.
In the configuration described in Patent Document 1, the teleform is supported in the tunnel by the gantry. When the teleform is reduced in diameter and sent forward, the teleform is placed on the gantry and moved.

  In the conventional NATM construction method, the gantry cannot be removed from the teleform unless the concrete is hardened and a predetermined strength is exhibited. In other words, it has been difficult to divert the gantry and move on to the next placing operation until the predetermined strength of the concrete is developed. Therefore, there was a limit to speeding up the construction. On the other hand, if the formwork is removed at an early stage in order to speed up the construction, there is a problem that the quality of the lining body is lowered.

JP 2008-308855 A

  An object of the present invention is to provide a tunnel lining method and a tunnel lining form support method capable of speeding up construction while ensuring the quality of the lining body.

The present invention employs the following means in order to solve the above problems.
That is, the method of supporting the tunnel lining formwork of the present invention includes a formwork body disposed inside the excavation hole excavated in a natural ground and having a formwork surface facing the inner peripheral surface of the excavation hole. One end thereof is disposed so as to be connected to the formwork body, the other end is supported by a support member fixed to the natural ground side, and the end of the formwork body is fixed.
Further, as a method of fixing one end of the support member, the support member may be connected to a lock bolt or an anchor member driven into the ground around the excavation hole, and the other end may be connected to the mold body. .
As means for fixing the end of the mold body, there are an anchor, a heavy object, and a beam, and these may be combined.
As described above, in addition to connecting one end of the support member to the lock bolt or the anchor member, the end portion of the form body can be fixed to firmly support the form body.
The support member may have one end connected to a steel support installed on the inner peripheral surface of the excavation hole and the other end connected to the mold body.

With such a configuration, the mold body is supported by the support member fixed to the ground and the end of the mold body is fixed, and when the secondary lining concrete is placed, the pressure of the secondary lining concrete is A supporting space such as a gantry is unnecessary and a space is formed below the formwork body supporting the secondary lining concrete. Therefore, it can be sent forward in the excavation direction through the formwork body and the like.
By connecting one end of the support member to a steel support fixed to the inner peripheral surface of the excavation hole, the mold body can be firmly supported by the support member.

Further, the tunnel lining method of the present invention includes a step of supporting the formwork body by the support member and installing the end part of the formwork body by the above-described method of supporting the tunnel lining formwork. A step of fixing, a step of placing concrete between the mold body and the excavation hole, a step of releasing the connection of the other end of the support member to the mold body, and the tunnel mold body And a step of releasing the mold body, and a step of feeding the removed mold body forward in the excavation direction in the excavation hole. To do.
Further, a plurality of the mold main bodies are continuously provided in the excavation hole along the excavation direction of the excavation hole.

With such a configuration, the mold body can support the pressure and load of the secondary lining concrete. Then, after reaching a predetermined strength, the support member is removed, and another mold body whose diameter has been reduced can be passed forward through the lower part of the mold body supporting the covering concrete.
As a result, a plurality of formwork bodies can be used, and tunnel lining can be quickly performed while securing a sufficient period of time for the strength of the secondary lining concrete to develop in each formwork body.

  Further, the tunnel lining method of the present invention includes a method for supporting the above-mentioned tunnel lining formwork, a step of supporting the formwork body by a gantry for supporting the formwork body, Fixing the end, placing concrete between the mold body and the excavation hole, and releasing the support of the mold body by the gantry to move the gantry forward in the excavation direction. A step, a step of releasing the connection of the other end of the support member to the formwork body, a step of releasing the fixing of the end of the tunnel formwork body, a step of releasing the formwork body, Feeding the demolded mold body forward in the excavation direction.

With such a configuration, the mold body can support the pressure and load of the secondary lining concrete in combination with the gantry. In addition to supporting from the inside, if used together with the gantry, the gantry can be removed early.
Then, after the predetermined strength is reached, the support member is removed, and the other mold body whose diameter has been reduced can be passed forward under the other mold body supporting the covering concrete.

  According to the present invention, the formwork body can support the secondary lining concrete in the excavation hole, so that the lower part of the formwork body supporting the secondary lining concrete is attached to the other formwork body. It can be passed and sent forward. Therefore, it is possible to quickly cover the tunnel while securing a sufficient period of time for the strength of the secondary lining concrete to be expressed to ensure the quality of the lining body.

It is sectional drawing which shows the conceptual structure of the formwork apparatus used with the supporting method of the tunnel lining form which concerns on this embodiment, and the lining method of a tunnel. It is side sectional drawing which shows notionally the tunnel lining method using a formwork apparatus. It is sectional drawing which shows the conceptual structure of the supporting member for supporting a formwork main body on the natural ground side. It is sectional drawing which shows the conceptual structure of the formwork apparatus used with the support method of the tunnel lining formwork which concerns on this embodiment, the support structure and end part fixing structure of a tunnel lining form, and the tunnel lining method is there. It is sectional drawing which shows the conceptual structure of the formwork apparatus used with the support method of the tunnel lining formwork which concerns on this embodiment, the support structure and end part fixing structure of a tunnel lining form, and the tunnel lining method is there.

  Hereinafter, with reference to the accompanying drawings, a method for supporting a tunnel lining form according to the present invention, a tunnel lining form support structure and an end fixing structure, a form for carrying out a tunnel lining method, This will be described with reference to the drawings.

FIG. 1 is a cross-sectional view illustrating a configuration of a formwork apparatus used in a tunnel lining form supporting method and a tunnel lining method according to the present embodiment. FIG. 2 is a sectional side view showing a tunnel lining method using a formwork apparatus.
As shown in FIGS. 1 and 2, the tunnel T is constructed by the NATM construction method.
That is, in order to construct the tunnel T, first, the natural ground G is excavated by a rock drill or blasting to form the excavation hole H. And concrete is sprayed on the internal peripheral surface of the excavation hole H, and the primary lining concrete 11 is formed by hardening this concrete.

  Further, a plurality of rock bolts 12 are driven radially from the excavation hole H into the surrounding natural ground G through the primary lining concrete 11. In this case, a steel support (not shown) may be installed on the inner peripheral surface of the excavation hole H with an interval in the axial direction of the tunnel T.

  Thereafter, a formwork device tunnel lining form 10 to be described later is installed on the inner circumference side of the primary lining concrete 11 covering the inner circumference surface of the excavation hole H. Next, concrete is cast and filled between the formwork device 10 and the primary lining concrete 11, and the secondary lining concrete 13 is formed by curing the concrete. After the secondary lining concrete 13 develops a predetermined strength, the lining body 15 of the tunnel T is constructed by removing the formwork device 10.

  The lining body 15 constructed in this manner is composed of a primary lining concrete 11, a rock bolt 12, and a secondary lining concrete 13, and the primary lining concrete 11 and the secondary lining concrete 13 are formed on the ground mountain G. It is integrated with the natural ground G by a plurality of driven lock bolts 12.

  The formwork apparatus 10 including the formwork body 20 is installed in the excavation hole H. The mold body 20 has a predetermined length along the direction in which the excavation holes H are continuous. The mold body 20 has a mold surface 20f opposed to the primary lining concrete 11 on the inner peripheral surface of the excavation hole H with an interval in the radial direction of the excavation hole H.

  The formwork body 20 includes a formwork member 21 connected in a plurality along the circumferential direction of the excavation hole H. Each mold member 21 has a circular arc shape in cross section. These formwork members 21 are rotatably connected to other formwork members 21 adjacent in the circumferential direction of the excavation hole H via hinges 22. Accordingly, the mold body 20 rotates the mold members 21 with the hinges 22 of the connecting portions, thereby expanding the diameter of the mold body 20 or expanding the diameter of the mold body 20 to reduce the diameter. Can be.

  Each mold member 21 is formed with a jack pressure receiving portion 23 on the inner peripheral side with respect to the hinge 22 at a connection portion with another mold member 21 adjacent in the circumferential direction of the excavation hole H. A jack 24 can be detachably interposed between the jack pressure receiving portions 23 and 23 of the mold members 21 and 21 adjacent in the circumferential direction. By applying a pressing force in a direction in which the jack pressure receiving portions 23, 23 are separated from each other by the jack 24, the mold body 20 is maintained in a state where it is expanded and expanded in diameter.

  In addition, as for the mold member 21D located in the both ends of the mold main body 20, only the one end side is connected with the mold member 21, and the other end side is provided with the grounding surface 21f installed on the bottom surface 14 of the excavation hole H. Have.

FIG. 3 is a cross-sectional view showing a configuration of a support member for supporting the formwork main body on the natural ground side.
As shown in FIG. 3, the septum holding member 40 is disposed on the outer peripheral side of the mold body 20, and supports the mold body 20 from the natural ground G around the excavation hole H.
The partition holding member 40 is driven into the natural ground G and fixed to the formwork body 20 and a nut member 41 connected to the tip of the lock bolt 12 protruding to the inner peripheral side of the primary lining concrete 11. And a steel rod 43 provided between the nut member 41 and the fixture 42.

  The nut member 41 has a screw hole 41 h, and the screw hole 41 h is screwed into a screw groove 12 m formed on the outer peripheral surface of the lock bolt 12.

  The fixture 42 is attached to the through hole 25 formed in the mold body 20. The fixture 42 includes a base member 44 along the inner peripheral surface of the mold body 20 and an adjustment member 45. The base member 44 has a screw hole (not shown) through which the adjustment member 45 passes. The adjustment member 45 has a male screw portion (not shown) that is screwed into the screw hole of the base member 44. By rotating the adjusting member 45 in the screw hole of the base member 44, the projecting dimension from the base member 44 changes.

  The steel rod 43 has one end connected to the nut member 41 and the other end connected to the adjustment member 45 of the fixture 42.

  Such an inner space holding member 40 can adjust the tension of the steel rod 43 by rotating the adjusting member 45 of the fixture 42 with respect to the screw hole (not shown) of the base member 44.

  By such a tension adjusting mechanism, after the secondary lining concrete is placed between the mold surface of the mold body and the excavation hole, the mold body 20 supported by each of the partition holding members 40 by the adjusting member 45. It is possible to partially adjust the pressure and load applied to.

  21D grounding surfaces 21f located at both ends of the mold body 20 are fixed to the bottom surface 14 of the excavation hole H by anchors 16.

In the example of FIG. 1, the septum holding member 40 is disposed in the vicinity of the top of the mold body 20. The inner space holding member 40 is provided at a plurality of positions with a space in the direction in which the excavation holes H are continuous with respect to the mold body 20.
In addition to this, the inner space holding member 40 may be installed at a plurality of locations at intervals in the circumferential direction of the mold body 20.

  Since the end portion of the main body 20 is fixed by the anchor 16, it is effective to control the deformation of the centle, particularly when the inner space holding member 40 is disposed in the vicinity of the tunnel top.

  The vicinity of the tunnel top means the upper half of the tunnel located above the tunnel spring line.

The mold body 20 is connected to the lock bolt 12 via the partition holding member 40, and 21D grounding surfaces 21 f located at both ends of the mold body 20 are fixed to the bottom surface 14 of the excavation hole H by the anchors 16. Thus, the mold body 20 can be firmly supported.
Next, a tunnel T lining method using the above-described formwork apparatus 10 will be described.

(Formwork device installation process)
In order to cover the tunnel T, the formwork apparatus 10 is installed in the excavation hole H excavated in the natural ground G. At this time, the mold body 20 is supported by the inner wall holding member 40, and the end of the mold body 20 is fixed with an anchor to install the mold body 20.

(Secondary lining concrete placing process)
Next, the secondary lining concrete 13 is placed between the mold body 20 and the excavation hole H.

(Reducing diameter of formwork device, forward feeding process)
For the secondary lining concrete 13, after a predetermined strength has been developed, the fixture 42 is removed, the connection to the mold body 20 at the other end of the septum holding member 40 is released, and both ends of the mold body 20 are The anchor 16 is fixed to the bottom surface 14. Then, the plurality of mold members 21 constituting the mold body 20 are folded at the hinges 22 of the connecting portions, the diameter of the mold body 20 is reduced, and the mold is removed from the placed concrete.

The mold body 20 having a reduced diameter is moved along a rail laid in the excavation hole H by a moving carriage (not shown) or a traveling wheel provided in the mold main body 20, and the excavation direction in the excavation hole H. Send forward.
Thereafter, the formwork apparatus 10 is installed again at a predetermined position in front of the excavation direction, and the above series of steps is sequentially repeated.

Here, as shown in FIG. 2, the said formwork apparatus 10 can use multiple sets. When a plurality of formwork apparatuses 10 are used, for example, the following steps are performed. That is, the second formwork apparatus 10B is installed forward in the excavation direction while the secondary lining concrete 13 is being placed by the first formwork apparatus 10A installed at a predetermined position. And after predetermined intensity | strength is expressed about the secondary lining concrete 13 cast | placed in the position of 10 A of 1st mold apparatuses, 10 A of 1st mold apparatuses are diameter-reduced. The first formwork apparatus 10A having a reduced diameter is placed at the position of the second formwork apparatus 10B, even if the secondary lining concrete 13 is placed at the position of the second formwork apparatus 10B. Even before the predetermined strength is developed for the secondary lining concrete 13 provided, it can be moved forward in the excavation direction.
In this way, it is possible to perform the construction by sequentially shifting the steps to be performed between the plurality of formwork apparatuses 10 that are located one after the other. Three or more sets of formwork devices 10 may be used.

  When performing the construction as described above, each formwork device 10 supports the formwork body 20 by the inner wall holding member 40 and fixes the bottom surface 14 by the anchors 16 at both ends of the formwork body 20. Thus, the mold body 20 can support the load and pressure by the secondary lining concrete 13. Therefore, the formwork body 20 which has been detached from the inner wall holding member 40, released from the anchor 16 and reduced in diameter, has another formwork body 20 which supports the secondary lining concrete 13 in front of the excavation direction. It can be sent forward by passing below.

  As described above, the mold body 20 is supported by fixing the inner wall holding member 40 fixed to the natural ground G side on the outer periphery side of the mold body 20 and the end of the mold body 20.

  Thereby, the formwork apparatus 10 can support the load and pressure of the secondary lining concrete 13 without requiring support by a gantry or the like. Therefore, the lower part of the mold body 20 supporting the secondary lining concrete 13 can be passed forward through the other mold body 20 having a reduced diameter.

Then, a plurality of formwork main bodies 20 are connected and used, and each formwork main body 20 is sequentially fed forward after the placement of the secondary lining concrete 13.
Thereby, it is possible to quickly cover the tunnel T while securing a sufficient period for the strength of the secondary lining concrete 13 to develop in each mold body 20.

  Therefore, according to the method according to the embodiment, it is possible to speed up the construction while ensuring the quality of the covering body 15.

  Next, another embodiment of the present invention will be described. In this embodiment, a gantry is combined with the previous embodiment. That is, the formwork apparatus 10 is supported by the gantry in the method for supporting a tunnel lining form, the structure for supporting a tunnel lining form, or the method for covering a tunnel according to the above embodiment.

  The present embodiment is basically the same as the above-described embodiment, but supports the formwork apparatus 10 by using the septum holding member 40, the anchor 16, and the gantry together. Therefore, when placing the secondary lining concrete, the formwork device 10 can be more reliably supported by these configurations. The gantry can also be used as a working scaffold.

  Since the formwork apparatus 10 is supported by the partition holding member 40 and the anchor 16, even before the predetermined strength of the secondary lining concrete 13 is expressed, that is, even if the secondary lining concrete 13 is young. The gantry can be moved by releasing the support of the formwork device 10 by the gantry.

And after predetermined intensity | strength expresses about the secondary lining concrete 13, the connection with the mold body 20 of the other end of the partition holding member 40 is cancelled | released, and fixation of the mold body 20 end part is cancelled | released, The frame device 10 is removed from the mold. The demolded formwork apparatus 10 is reduced in diameter, and can be moved through the other formwork apparatus 10 in front of the excavation direction.
At this time, the gantry is newly installed at the position where the secondary lining concrete 13 is to be placed. Since the moved formwork apparatus 10 is reduced in diameter, it can be moved between the natural ground G and the gantry and deployed.

  As the gantry, for example, a portal gantry is used, but various shapes can be adopted as long as they can support the formwork apparatus and do not hinder the movement of the formwork apparatus. .

  The tunnel lining form support method, tunnel lining form support structure, and tunnel covering method of the present invention are not limited to the above-described embodiment described with reference to the drawings. Various modifications can be considered in the technical scope.

  For example, the anchor 16 may be replaced with the heavy object 17 shown in FIG. When fixing the end of the mold body 20 with the heavy object 17, it is easy to install and remove the heavy object 17.

  Moreover, you may fix an edge part with the beam 18 shown in FIG. Usually, when placing secondary lining concrete, it is cast at the same height on the left and right, so that the beam 18 is pressed with the same force from the left and right, so that a compressive force acts on the beam.

  Furthermore, the end of the mold body 20 may be fixed by combining the anchor 16, the heavy object 17, and the beam 18.

  In addition to this, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate without departing from the gist of the present invention.

10 Formwork equipment (formwork for tunnel lining)
11 Primary lining concrete 12 Rock bolt 13 Secondary lining concrete 14 Bottom surface 15 Covering body 16 Anchor 17 Heavy object 18 Beam 20 Formwork body 20f Formwork surface 21 Formwork member 40 Separation holding member 41 Nut member 42 Fixing tool 43 Steel bar 50 Anchor member 60 Steel support G Ground mountain H Drilling hole T Tunnel

Claims (5)

A structure for supporting a tunnel lining formwork having a formwork surface facing the inner peripheral surface of the excavation hole inside the excavation hole excavated in a natural ground,
In the part facing the inner peripheral surface of the excavation hole of the mold, one end of the septum holding member is attached to the mold body, and the other end is fixed to the natural ground side to support the mold,
The inner space holding member includes a fixture connected to a mold, a nut member connected to a natural ground side, and a steel bar provided between the fixture and the nut member,
The fixture is mounted in a through hole formed in the mold, and includes a base member and an adjustment member along the inner periphery of the mold,
The base member includes a screw hole through which the adjustment member passes,
The previous-stage adjustment member includes a male screw portion that is screwed into the screw hole of the base member,
A structure for supporting a tunnel lining form, characterized in that the end of the form is fixed to the bottom of the tunnel. The support structure for a tunnel lining form according to claim 1, wherein the inner space holding member is disposed in the vicinity of the top of the tunnel. The support structure for a tunnel lining formwork according to claim 1 or 2, wherein an end of the formwork body is fixed to a tunnel bottom by an anchor. The support structure for a tunnel lining formwork according to claim 1 or 2, wherein an end of the formwork body is fixed with a heavy object placed thereon. The support structure for a tunnel lining formwork according to claim 1 or 2, wherein the ends of the formwork body are connected by a beam.

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