JP2009068276A - Shield tunnel widening method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shield tunnel widening method which is inexpensively carried out without using a special shield machine etc. <P>SOLUTION: According to the shield tunnel widening method, after construction of a shield tunnel by assembling segments, a chemical solution is poured into the shield tunnel to form a poured section 10a, and then an upper segment 5a is removed, followed by excavating the poured section 10a, to thereby form an excavated section 15a at a widening scheduled location. Thereafter a lower segment 7a is removed, and a lower portion widening segment 19 is set, followed by removing side segments 9a, 9b, 9c. Then the removed lower segment 7a and the side segments 9a, 9b, 9c are set at the widening scheduled location, and an upper widening segment 25 is set, followed by setting the upper segment 5a at the widening scheduled location. In this manner widening of the shield tunnel is carried out. In order to ensure the rigidity of the tunnel during execution of widening work, a jack timber 11, a lower support 21, and an upper support 27 are set in the tunnel. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for widening a shield tunnel.

  Conventionally, as a method for widening the shield tunnel, there has been a construction method in which the primary segment is disassembled from the expansion shield transmission base and is expanded with the expansion shield.

  Further, recently, a method has been proposed in which two shield tunnels are arranged side by side by a shield method, and then the shield tunnel is widened by excavating between them with a rectangular shield (see, for example, Patent Document 1). ).

JP 2003-148086 A

  However, in the method of disassembling the primary segment, the primary segment after disassembly is wasted, which is disadvantageous in terms of cost. In addition, the construction method disclosed in Patent Document 1 cannot be efficiently applied because it uses a special shield machine or a special segment, and is not widely applicable.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an inexpensive method for widening a shield tunnel without using a special shield machine or the like.

  In order to achieve the above-described object, the first invention includes a step (a) of assembling a segment by a shield machine to construct a shield tunnel, a step (b) of excavating a planned widening portion of the shield tunnel, A method of widening a shield tunnel, comprising: a step (c) of removing a segment of the shield tunnel to be widened and a step (d) of installing the removed segment at a position after the widening. is there.

  In addition, it is desirable that the method further includes a step of installing a middle column in the shield tunnel between the step (a) and the step (b), and has been widened or widened from the upper end or / and the lower end of the middle column. It is desirable to further include a step of installing struts on the inner segment surface.

  Preferably, the method further comprises a step of installing an upper widened segment and a lower widened segment between the step (c) and the step (d) above and below the portion to be widened, The lower widened segment is preferably plate-shaped and preferably has a claw for coupling with an adjacent segment. In the step of installing the lower widened segment, the lower widened segment is provided with an expansion tube that can be expanded by injecting a fluid. It is desirable to further comprise a step of installing underneath.

  The space for re-installing the upper segment may further include a step of dug to the natural ground side, and the widened cross-sectional area is made larger than that of the adjacent ring to form a tapered shield tunnel. Also good.

  According to the present invention, an inexpensive shield tunnel widening method is provided without using a special shield machine or the like.

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

FIG. 1 is a flowchart of a method for widening a shield tunnel according to the first embodiment, FIGS. 2A to 2E are plan views of the shield tunnel during widening, and FIGS. 3 and 4 are during widening. 3 is a cross-sectional view of the shield tunnel, FIG. 3 is a cross-sectional view taken along line AA in FIG. 2, and FIG. 4 is a cross-sectional view taken along line BB in FIG.
First, a shield tunnel is constructed by a shield excavator. Thereafter, the shield tunnel is widened.
As shown in FIG. 3A, this shield tunnel has a circular cross section, and the segment on the left side of the cross section is referred to as the upper segment 5a, side segments 9a, 9b, 9c, and lower segment 7a from the top. The remaining segments that do not move are collectively referred to as tunnel 3.

  First, as shown in FIGS. 2 (a) and 3 (a), a chemical solution is injected into a portion to be widened on the side of the tunnel 3 to provide an injection portion 10a (step 101).

  As a chemical | medical solution to inject | pour, a cement type solidification material, a water glass type solidification material, and a polymer type solidification material are preferable.

  Next, as shown in FIGS. 2B and 3B, the middle pillar 11 is provided in the vertical direction of the tunnel 3. Further, the upper segment 5a is removed and temporarily stored. The injection part 10a is excavated from the part where the upper segment 5a is removed, and an excavation part 15a is provided (step 102).

  The middle pillar 11 is provided in order to resist vertical earth pressure and water pressure, and it is preferable to provide a jack 13.

  Next, as shown in FIG. 3 (c), the lower segment 7a is removed and temporarily stored in another location. The expansion tube 17 is installed on the natural ground side where the lower segment 7a is removed, and the lower widened segment 19 is installed thereon (step 103).

  The expansion tube 17 expands by injecting a fluid such as mortar or water from the inside of the shield tunnel, and generates pressure to push the lower widened segment 19 toward the inside of the shield tunnel. It is provided for alignment of the lower widened segment 19.

  FIG. 5 is a view showing the lower widened segment 19, and has a claw portion 31 in addition to the flat segment portion 33. By the claw portion 31, the lower widened segment 19 is engaged with the segment of the adjacent tunnel 3.

  Depending on the length of the expected widening width, a plurality of lower widening segments 19 may be provided.

  Next, as shown in FIG. 3D, the lower segment 7a is re-installed adjacent to the lower widened segment 19, the side segments 9a, 9b, 9c are removed and re-installed at the planned widened location. . Further, the lower support column 21 is installed in the vicinity of the side segment 9b (step 104).

  The lower support column 21 is preferably provided so that the side segments 9a, 9b, 9c after re-installation do not fall inside the tunnel, and has a jack 23.

  Next, as shown in FIG. 3E, the upper widened segment 25 is installed (step 105).

  The upper widened segment 25 has a claw portion 31 similar to the lower widened segment 19 and is engaged with the segment of the adjacent tunnel 3 by the claw portion 31 so as not to fall from the upper part to the tunnel inner side.

  Next, as shown in FIGS. 2 (c) and 3 (f), the stored upper segment 5a is placed at a planned widening portion between the upper widening segment 25 and the side segment 9a. Thereafter, the upper support column 27 is installed (step 106).

  In order to install the upper segment 5a, it is preferable that the excavation part 15a is widened, the upper segment 5a is once pushed out to the natural ground side, and then pulled back into the tunnel. Moreover, when excavating the excavation part 15a, it is preferable to excavate a space for installing the upper segment 5a in advance. The same applies to step 112 where the upper segment 5b is installed.

  It is preferable that the upper column 27 also has a jack 29.

  In steps 101 to 106, the widening of the first span is completed, and then in steps 107 to 112, the widening of the portion adjacent to the widened portion is started.

  As shown to Fig.4 (a), a chemical | medical solution is inject | poured into the widening plan place of the side of the tunnel 3, and the injection | pouring part 10b is provided. The condition of the natural ground is visually observed, and chemical liquid injection in the tunnel axis direction may be performed as necessary (step 107).

  Next, as shown in FIGS. 2D and 4B, the middle pillar 11 is provided in the longitudinal direction of the cross section of the tunnel 3. The injection portion 10b is excavated from the portion widened in steps 101 to 106, and the excavation portion 15b is provided (step 108).

  Next, as shown in FIG. 4C, the lower segment 7b is removed and temporarily stored in another location. The expansion tube 17 is installed on the natural ground side where the lower segment 7b is removed, and the lower widened segment 19 is installed thereon (step 109).

  Next, as shown in FIG. 4 (d), the lower segment 7b is re-installed adjacent to the lower widened segment 19, the side segments 9d, 9e, 9f are removed and re-installed at the planned widened location. . Moreover, the lower support | pillar 21 is installed in the side part segment 9e vicinity (step 110).

  Next, as shown in FIG.4 (e), the upper segment 5b is removed and the upper widening segment 25 is installed (step 111).

  Next, as shown in FIG. 2 (e) and FIG. 4 (f), the temporarily stored upper segment 5b is placed at the planned widening portion between the upper widening segment 25 and the side segment 9d. Thereafter, the upper column 27 is installed (step 112).

  Thereafter, steps 107 to 112 are repeated until widening is completed up to the section where the shield tunnel should be widened.

  According to the present embodiment, the shield tunnel can be widened with an arbitrary widening width in an arbitrary section. Moreover, since the upper segment 5, the side segment 9, and the lower segment 7 which have been disassembled in the conventional method can be reused, the cost can be reduced.

  Furthermore, according to the present embodiment, since no special construction machine or special segment is used, the cost can be reduced.

  Furthermore, according to the present embodiment, there are high degrees of freedom in selecting the direction in which the tunnel is widened, it is easy to achieve stability of the ground, easy to take measures for settlement after construction, and easy to position the segments. Have.

Next, a second embodiment will be described.
FIG. 6 is a plan view of a shield tunnel widened by the shield tunnel widening method according to the second embodiment. In the present embodiment, the widening width is changed for each span, and the tapered portion 35 is formed. The tapered portion 35 can be used as an entrance or exit to a highway ramp or emergency parking zone.

  The preferred embodiment of the method for widening a shield tunnel according to the present invention has been described above with reference to the accompanying drawings, but the present invention is not limited to such an example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the technical idea disclosed in the present application, and these are naturally within the technical scope of the present invention. Understood.

The flowchart which shows the widening method which concerns on 1st Embodiment Plan view of shield tunnel in step 101 Plan view of shield tunnel in step 102 Plan view of shield tunnel in step 106 Plan view of shield tunnel in step 108 Plan view of shield tunnel in step 112 AA sectional view of the shield tunnel in steps 101 to 106 BB sectional view of shield tunnel in steps 107-112 Diagram showing the lower widened segment Plan view of a shield tunnel widened by the widening method according to the second embodiment

Explanation of symbols

3 ......... Tunnel 5 ......... Upper segment 7 ......... Lower segment 9 ......... Side segment 10 ......... Injection part 11 ... …… Medium pillar 13 ......... Jack 15 ......... Drilling part 17 ... … Expansion tube 19 ……… Lower widened segment 21 ………… Lower support 23 ……… Jack 25 ……… Upper widened segment 27 ……… Upper support 29 ……… Jack 31 ……… Claw 33 ……… Segment Part 35 ... Taper part

Claims (8)

(A) constructing a shield tunnel by assembling segments with a shield machine;
A step (b) of excavating the planned widening portion of the shield tunnel;
A step (c) of removing a segment of the shield tunnel to be widened;
Installing the removed segment at a position after widening (d);
A method for widening a shield tunnel, comprising:   The method for widening a shield tunnel according to claim 1, further comprising a step of installing a middle pillar in the shield tunnel between the step (a) and the step (b).   3. The method for widening a shield tunnel according to claim 2, further comprising the step of installing a column in a truss shape on the segment surface that has been widened or widened from the upper end or / and the lower end of the middle pillar.   The shield according to claim 1, further comprising a step of installing an upper widened segment and a lower widened segment at the upper and lower portions of the planned widening portion between the step (c) and the step (d). Tunnel widening method.   5. The method for widening a shield tunnel according to claim 4, wherein the upper widened segment and the lower widened segment are plate-shaped and have claws for coupling with adjacent segments.   6. The shield tunnel according to claim 4, further comprising a step of installing an expansion tube that can be expanded by pouring fluid under the lower widening segment in the step of installing the lower widening segment. Widening method.   The method for widening a shield tunnel according to any one of claims 1 to 6, further comprising a step of excavating a space for installing the upper widened segment at a position after widening to a natural ground side.   8. The method for widening a shield tunnel according to claim 1, wherein a taper-shaped shield tunnel is formed by enlarging a widened cross-sectional area as compared with an adjacent ring.

Images