JP7456954B2 - Reinforcement structure and reinforcement method - Google Patents

Description

The present disclosure relates to a reinforcement structure and method for reinforcing a tunnel lining.

Patent Document 1 describes a method for constructing an underground structure. This underground structure is a large-section tunnel constructed in the confluence area of the main line shield tunnel and the branch line shield tunnel. An underground cavity extending in the axial direction of the underground structure is formed inside the underground structure. The cross-sectional area of the underground cavity decreases from one end of the underground structure to the other end, following the outlines of the main line shield tunnel and the branch line shield tunnel. The underground structure includes an outer skeleton of an underground cavity formed by connecting a plurality of shield tunnels. In the outer skeleton, a connection road is constructed to connect circumferentially adjacent shield tunnels to each other, and reinforced concrete is poured into the shield tunnel and the connection road. The plurality of shield tunnels are composed of a full-length shield tunnel that extends from one end to the other end of the outer shell, and short shield tunnels that are shorter than the full-length shield tunnel.

In this underground structure construction method, a plurality of shield tunnels are constructed in the circumferential direction between one end and the other end of the planned underground structure area where the underground structure is planned to be constructed. After constructing an outer shell consisting of connected shield tunnels, an underground cavity is formed by excavating the inner peripheral area of the outer shell. Then, the full-length shield tunnel is constructed so that it does not extend from one end to the other, and the short shield tunnel is constructed so that it does not extend from one end to the other. Construct it so that it becomes smaller towards the other end.

Patent Document 2 describes a method for constructing a large cross-section tunnel. The large-section tunnel is formed by a large-section lining body that can contain the main tunnel and the branch tunnel. The large cross-section lining body includes a plurality of tunnels arranged in parallel in a cylindrical shape, a hardened concrete filling body filled in each tunnel, and a main reinforcement arranged so as to straddle the plurality of tunnels. The plurality of tunnels include a plurality of leading tunnels formed at intervals and a trailing tunnel formed between adjacent leading tunnels.

In the leading tunnel, leading reinforcing bars and leading filling concrete are provided, and in the trailing tunnel, trailing reinforcing bars and trailing filling concrete are provided. Adjacent leading tunnels and trailing tunnels are arranged side by side with some parts overlapping. The main reinforcing bars penetrate the leading tunnel and the trailing tunnel in the circumferential direction, and are arranged on the radially inner side and the radially outer side of the large-section tunnel, respectively. A plurality of shear reinforcing bars extending in a direction intersecting the main reinforcements are arranged between the pair of main reinforcements.

In the method of constructing a large cross-section tunnel, a plurality of preceding tunnels are installed in parallel, and after placing preceding reinforcing bars in each preceding tunnel, each preceding tunnel is filled with preceding filling concrete. Then, a trailing tunnel is constructed between adjacent leading tunnels, and trailing reinforcing bars are arranged within the trailing tunnel. In constructing the trailing tunnel, a part of the cross section of the adjacent leading tunnel is cut, and the trailing tunnel is constructed so that the outer surface of the trailing tunnel comes into contact with the leading filling concrete. More specifically, at the joint between the leading tunnel and the trailing tunnel, a part of the skin plate of the trailing tunnel is removed, and a spacer is installed between the main girder of the steel segment of the trailing tunnel and the leading filling concrete. intervene. By bringing the outer surface of the trailing tunnel into contact with the preceding filling concrete via this spacer, deformation of the trailing tunnel is suppressed.

JP 2018-3398 Publication Japanese Patent Application Publication No. 2018-12945

In the tunnel lining described above, deformation of the tunnel is suppressed by interposing members such as spacers between the main girder of the steel segment and the concrete. However, since the spacer is provided between the main girder and concrete, there is a concern that when an external force is applied, the spacer may not be able to appropriately transmit the external force to the main girder. Therefore, when an external force is applied, it is required to appropriately transmit the external force to the main girder to more reliably suppress deformation of the tunnel.

The present disclosure aims to provide a reinforcement structure and a reinforcement method that can more reliably suppress deformation of a tunnel.

The reinforcement structure according to the present disclosure is a reinforcement structure for a tunnel lining body having main girders arranged at predetermined intervals in the axial direction of the tunnel and extending in the circumferential direction of the tunnel, the reinforcement structure being connected to the main girders. and a reinforcing member connected to the support member, and the support member includes a connection part welded to the main girder, a connection part extending from the connection part to the connection part, The tunnel lining has a fixed connecting part and a joint part connected to a reinforcing member, and the main girder of the tunnel lining is supported by the reinforcing member.

With this reinforcing structure, external force can be directly transmitted to the main girder via the support member, so the external force can be appropriately transmitted to the main girder and deformation of the tunnel can be reliably suppressed. Further, the support member includes a connecting part connected to the main girder, a connecting part extending in a direction crossing the connecting part, and a joint part fixed to the connecting part and the connecting part, and the connecting part is welded to the main girder. and the joint portion is connected to the reinforcing member. Therefore, the strength of the support member can be increased by the connecting portion, the coupling portion, and the joint portion, so that external force can be appropriately transmitted to the main girder, and deformation of the tunnel can be suppressed more reliably.

The connecting portion may be provided on a pair of upper and lower flanges that extend from the main girder, and the connecting portion may be a web that connects the pair of flanges. In this case, a shaped steel such as an H-shaped steel can be used as the supporting member, so it is possible to provide a highly versatile supporting member.

The joint portion may be a joint plate fixed to an end of the connecting portion and the connecting portion opposite to the main girder. In this case, the external force can be more directly transmitted to the main girder via the reinforcing member and the supporting member, resulting in a stronger reinforced structure.

The support member may have a recess into which the main beam is inserted. In this case, since the support member can be easily attached to the main girder, the workability of tunnel construction can be improved.

A reinforcing method according to one aspect of the present disclosure includes a tunnel lining having main girders arranged at predetermined intervals in the axial direction of the tunnel and extending in the circumferential direction of the tunnel, and a skin plate supported by the main girders. A method for reinforcing a body, comprising the steps of: connecting a support member to a main girder; connecting a reinforcing member to the support member to support the main girder; and removing a skin plate. , a connecting portion welded to the main girder, a connecting portion extending in a direction crossing the connecting portion, and a joint portion to which the connecting portion and the connecting portion are fixed and connected to the reinforcing member.

With this reinforcement method, the external force can be directly transmitted to the main girder via the support member, so the external force can be appropriately transmitted to the main girder and deformation of the tunnel can be reliably suppressed. The support member includes a connecting part connected to the main girder, a connecting part extending in a direction crossing the connecting part, and a joint part fixed to the connecting part and the connecting part, and the connecting part is welded to the main girder. At the same time, the joint portion is connected to the reinforcing member. Therefore, the strength of the support member can be increased by the connecting portion, the coupling portion, and the joint portion, so that external force can be appropriately transmitted to the main girder, and deformation of the tunnel can be suppressed more reliably.

In a reinforcing method according to another aspect of the present disclosure, a trailing tunnel is constructed after the leading tunnel, and the trailing tunnel is arranged at predetermined intervals in the axial direction of the trailing tunnel, and in the circumferential direction of the trailing tunnel. A method for reinforcing a trailing tunnel lining having an extending main girder and a skin plate supported by the main girder, the method comprising: connecting a support member to the main girder of the trailing tunnel lining; a step of connecting one end of the reinforcing member to the reinforcing member, and a step of supporting the main girder by connecting the other end of the reinforcing member to the preceding tunnel lining of the preceding tunnel or a supported member installed in the preceding tunnel; removing the skin plate of the trailing tunnel; a joint portion that is fixed and connected to the reinforcing member.

In this reinforcing method, the external force is transmitted to the main girder via the reinforcing member and the support member, so that the external force can be appropriately transmitted to the main girder and deformation of the tunnel can be reliably suppressed. Further, as described above, the support member has a connecting portion, a coupling portion, and a joint portion that are connected to the main girder, and the connecting portion is welded to the main girder and the joint portion is connected to the reinforcing member. Therefore, external force can be appropriately transmitted to the main girder by the connecting portion, the coupling portion, and the joint portion, and deformation of the tunnel can be suppressed more reliably.

The trailing tunnel is constructed by cutting a part of the leading tunnel lining, and may include a step of providing a leading support structure that supports the cut leading tunnel lining. In this case, the cut portion of the preceding tunnel lining can be supported by the preceding support structure.

In the process of connecting the support members, the support members may be installed on the main girders by inserting the main girders into the support members. In this case, the support members can be installed by inserting them into the main girders, so that the support members can be easily attached to the main girders. This can improve the ease of tunnel construction.

According to the present disclosure, deformation of the tunnel can be suppressed more reliably.

It is a sectional view showing typically the reinforcement structure of the tunnel lining body concerning a 1st embodiment. It is a sectional view showing a main girder, a supporting member, and a reinforcing member of a tunnel lining body. 3 is a view taken along the line AA in FIG. 2. FIG. It is a sectional view showing typically the reinforcement structure of a leading tunnel lining body and a trailing tunnel lining body according to a second embodiment. FIG. 5 is a cross-sectional view showing the main girder, support member, and reinforcing member of the trailing tunnel lining body of FIG. 4 . It is a figure which shows the process of the reinforcement method of the leading tunnel lining body and the following tunnel lining body based on embodiment. 7 is a diagram illustrating a process continued from FIG. 6. FIG. FIG. 8 is a diagram showing a process subsequent to that shown in FIG. 7; 9 is a diagram illustrating a step continued from FIG. 8. FIG. FIG. 9 is a diagram showing a step continued from FIG. 9;

Hereinafter, embodiments of a reinforcing structure and a reinforcing method according to the present disclosure will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description will be omitted as appropriate. In addition, some parts of the drawings may be simplified or exaggerated for ease of understanding, and the dimensional ratios and the like are not limited to those shown in the drawings.

(First embodiment)
The reinforcing structure 1 and the reinforcing method according to the present embodiment are, for example, a reinforcing structure and a reinforcing method for reinforcing a tunnel between two tunnel lining bodies. The reinforcement structure 1 as an example is a cut-and-spread structure of two tunnel lining bodies provided underground. That is, the reinforcing structure 1 constitutes an incised frame of two tunnel lining bodies. The reinforcing method according to the present embodiment is a method of cutting and widening two tunnel lining bodies, and is executed, for example, in cutting and expanding two tunnel lining bodies.

For example, the reinforcement structure 1 is interposed between a leading tunnel lining 2A, which is one of the two tunnel linings, and a trailing tunnel lining 2B, which is the other of the two tunnel linings. In this state, the leading tunnel lining 2A and the trailing tunnel lining 2B are reinforced. The leading tunnel lining 2A and the trailing tunnel lining 2B are lined up along the opposing direction D4 in which the leading tunnel lining 2A and the trailing tunnel lining 2B face each other. Each of the preceding tunnel lining body 2A and the trailing tunnel lining body 2B is a shield tunnel including an outer skeleton constructed by, for example, a shield excavation method or a shield propulsion method.

In a shield tunnel, a shield tunneling machine excavates underground, and the segments 10 that become the walls of the tunnel are assembled behind the shield tunneling machine. The segments 10 assembled by excavating with a shield tunneling machine become the respective outer shells of the preceding tunnel lining 2A (preceding tunnel) and the trailing tunnel lining 2B (tracing tunnel). In the following, when there is no need to distinguish between the leading tunnel lining 2A and the trailing tunnel lining 2B, the leading tunnel lining 2A and the trailing tunnel lining 2B will be collectively referred to as the tunnel lining 2. .

For example, the tunnel lining body 2 is provided with a support 4 for reinforcing the inside of the tunnel. As an example, the tunnel interior reinforcement shoring 4 includes a first shoring 4b extending in the vertical direction D1, and a leading tunnel lining 2A and a trailing tunnel lining 2B facing each other from the upper end of the first shoring 4b. and a second support 4c extending obliquely downward toward the opposing area A. The first shoring 4b includes a pair of support parts 4d installed on the inner circumferential surface S of the tunnel lining body 2, and a rod-shaped part 4f that connects the pair of support parts 4d to each other. The second shoring 4c includes a support portion 4g provided at a position adjacent to the opposing region A on the inner circumferential surface S of the tunnel lining body 2, and a rod-shaped portion 4h that connects the support portions 4d and 4g to each other. However, the configuration of the tunnel interior reinforcement support 4 is not limited to the above-described example of the first support 4b and the second support 4c, and can be changed as appropriate.

For example, the tunnel lining 2 includes a plurality of segments 10. A tunnel is constructed by connecting a plurality of segments 10 along the axial direction D2 of the tunnel. The segment 10 includes a main beam 11, a skin plate 12, and a plurality of longitudinal ribs 13 (see FIG. 2). In addition, in FIG. 1, the illustration of the segments 10 is simplified in order to facilitate understanding of the entire tunnel lining body 2.

The reinforcement structure 1 includes a support member 20 connected to the main girder 11 and a reinforcement member 30 connected to the support member 20. The support member 20 is a member that supports the outer shell of the tunnel lining body 2 and is interposed between the tunnel lining body 2 and the reinforcing member 30. The support member 20 will be explained in detail later. The reinforcing member 30 functions, for example, as a bracing member that is interposed between the pair of tunnel lining bodies 2 and reinforcing the pair of tunnel lining bodies 2 . Specifically, the reinforcing member 30 connects and supports the support member 20 connected to the preceding tunnel lining 2A and the support member 20 connected to the trailing tunnel lining 2B.

For example, the reinforcing structure 1 includes a plurality of reinforcing members 30 lined up along the vertical direction D1. The reinforcing member 30 is, for example, a member that is gradually installed as the earth is excavated. That is, as the ground between the leading tunnel lining 2A and the trailing tunnel lining 2B is excavated, the reinforcing member 30 located above is installed, and the ground below the reinforcing member 30 is further excavated. After that, the lower reinforcing member 30 is installed. In the example of FIG. 1, reinforcing members 30 are installed on the upper side, the lower side, and the center of the tunnel lining body 2 in the vertical direction D1, respectively. As an example, two reinforcing members 30 are installed above the tunnel lining 2, one below the tunnel lining 2, and one reinforcing member 30 at the center of the tunnel lining 2 in the vertical direction D1. There is.

The reinforcing member 30 includes a strut (intermediate member) 31 extending in the opposing direction D4, a jack 32 interposed between the pair of struts 31, and a brace 33 connected to each of the pair of support members 20. and has. The riser 33 extends in the axial direction D2 between the support member 20 and the strut 31, and transmits the pressure acting from the tunnel lining body 2 to the strut 31. The strut 31 extends in the opposing direction D4 between the riser 33 and the jack 32. The jack 32 may be a hydraulic jack or a Kirin jack, and the type of jack 32 is not particularly limited. The jack 32 supports each strut 31 in the opposing direction D4 between the strut 31 extending toward the preceding tunnel lining 2A and the strut 31 extending toward the trailing tunnel lining 2B. It is a telescopic member. The supporting member 20 and the reinforcing member 30 are buried in concrete, and constitute a structure B having a U-shape in cross section, for example.

FIG. 2 is an enlarged side sectional view of a portion of the segment 10, the support member 20, and the reinforcing member 30. 3 is a view taken along the line AA in FIG. 2. FIG. As shown in FIGS. 2 and 3, the main girder 11 is a steel main girder extending in the circumferential direction D3 of the tunnel lining body 2. The skin plate 12 is a member that constitutes the outer peripheral surface of the tunnel lining body 2. The skin plate 12 is connected to the outer peripheral side of the main girder 11 and separates the tunnel lining body 2 from the ground.

The skin plate 12 is made of, for example, a curved plate-shaped steel material having an arcuate cross section, and functions as a partition wall that separates the tunnel lining body 2 from the ground. The skin plate 12 at the portion where the support member 20 is provided is cut out and removed in advance before the support member 20 is provided. In FIG. 3, the excised skin plate 12 is indicated by a two-dot chain line. The main girder 11 includes, for example, an inner main girder 11A and an outer main girder 11B arranged along the axial direction D2. The main girder 11 has a plate-like portion 11b that extends in the circumferential direction D3 of the tunnel and in the radial direction of the tunnel and has a thickness in the axial direction D2. The vertical ribs 13 are ribs that extend in the axial direction D2 and the radial direction of the tunnel and have a thickness in the circumferential direction D3, and are arranged so that the plurality of vertical ribs 13 are lined up along the circumferential direction D3. has been done.

The support member 20 includes a joining part 21 joined to the main girder 11, a connecting part 22 extending from the joining part 21, and a joint part 23 connected to the reinforcing member 30. The connecting portion 22 is fixed to the joint portion 23. The joint portion 21 has a connecting portion 21c connected to the main girder 11. For example, the connecting portion 21c is a part of a pair of upper and lower flanges, and the connecting portion 22 is a web that connects the pair of flanges to a portion other than the connecting portion 21c of the pair of upper and lower flanges.

The connecting portion 21c is configured as a part of a plate-shaped member, for example. As an example, a plate-shaped member extends in the axial direction D2 and the opposing direction D4, and has a thickness in the vertical direction D1. The connecting portion 21c is provided, for example, on the end surface 21b facing the main girder 11. The connecting portion 21c is, for example, a recessed portion (concave shape) into which the main beam 11 is inserted. The support member 20 is welded to the main girder 11 with the plate-shaped portion 11b of the main girder 11 inserted into the recess. In this case, the connection structure between the main girder 11 and the support member 20 can be made strong against twisting, and furthermore, the connecting portion 21c can be easily connected to the main girder 11 by insertion. As an example, the connecting portion 21c is recessed in the opposing direction D4 at the center of the end surface 21b in the axial direction D2. However, the form of the connecting portion is not limited to the connecting portion 21c, which is a recessed portion. For example, the connecting portion may be made of a steel material having a flange-shaped through hole and a bolt/nut, and may connect the main girder 11 and the support member 20, and the form of the connecting portion may be changed as appropriate.

The connecting portion 22 has, for example, a plate shape. The connecting portion 22 extends in both the vertical direction D1 and the opposing direction D4, and has a thickness in the axial direction D2. The connecting portion 22 has an end surface 22b facing the main beam 11, and the end surface 22b extends along the main beam 11. In the example of FIG. 2, the end surface 22b extends diagonally along the main beam 11.

The joint portion 23 is a joint plate that functions as a joint connecting the support member 20 and the reinforcing member 30 to each other. The joint portion 23 is located on the opposite side of the connection portion 21c and the connecting portion 22 from the main girder 11. The joint portion 23 extends in both the vertical direction D1 and the axial direction D2 and has a plate thickness in the opposing direction D4. For example, the joint portion 23 is fixed to the connecting portion 22 by welding. The joint portion 23 is fixed to the reinforcing member 30 (belt 33) by, for example, a bolt and nut fixing member B1.

The riser 33 is, for example, a section steel (an example is an H section steel) including a pair of flanges 33b and a web 33c. The pair of flanges 33b are lined up in the opposing direction D4, and the web 33c connects the pair of flanges 33b to each other. The flange 33b extends in both the vertical direction D1 and the axial direction D2, and has a thickness in the opposing direction D4. The web 33c extends in both the axial direction D2 and the opposing direction D4, and has a thickness in the vertical direction D1.

Of the pair of flanges 33b, the joint portion 23 is joined to the flange 33b located on the main girder 11 side by a bolt/nut fixing member B1. The belly riser 33 includes, for example, a stiffener 33d. The stiffener 33d has an L shape. The stiffener 33d has a first surface portion 33f that contacts the inner surface of the flange 33b, and a second surface portion 33g that is bent from the first surface portion 33f and contacts the web 33c.

The first surface portion 33f of the stiffener 33d is joined to the flange 33b via a bolt/nut fixing member B2. For example, the tummy tuck 33 includes a plurality of stiffeners 33d. Each stiffener 33d is joined to an extension of the support member 20 in the opposing direction D4 and an extension of the strut 31 in the opposing direction D4, respectively. By providing the tummy tuck 33 with the stiffener 33d in this way, the rigidity of the tummy tuck 33 can be increased.

The reinforcing member 30 includes, for example, a joining plate 34 that joins the strut 31 to the rib 33. The joint plate 34 is welded and fixed to the end of the strut 31 in the opposing direction D4. The joint plate 34 extends in both the vertical direction D1 and the axial direction D2, and has a thickness in the opposing direction D4. The joining plate 34 is joined to the flange 33b of the riser 33 via a bolt/nut fixing member B3. For example, the position of the strut 31 in the axial direction D2 is shifted from the position of the support member 20 in the axial direction D2.

The position of the strut 31 in the axial direction D2 is adjacent to the position of the support member 20 in the axial direction D2. The strut 31 is a shaped steel (an example is an H-shaped steel) including a pair of flanges 31b and a web 31c. The pair of flanges 31b are lined up in the vertical direction D1, and the web 31c connects the pair of flanges 31b to each other. The flange 31b extends in both the axial direction D2 and the opposing direction D4, and has a thickness in the vertical direction D1. The web 31c extends in both the vertical direction D1 and the opposing direction D4, and has a thickness in the axial direction D2. Each of the flange 31b and the web 31c is joined to the riser 33 via the joining plate 34 by a bolt/nut fixing member B3.

Next, a reinforcing method according to this embodiment will be explained. First, as shown in FIG. 1, a preceding tunnel lining body 2A is constructed (step of constructing a preceding tunnel lining body). At this time, a preceding tunnel lining body 2A extending in the axial direction D2 is constructed in the area where the tunnel is to be constructed. A shield excavator is used to construct the preceding tunnel lining 2A, and the preceding tunnel lining 2A is constructed while excavating the ground with the shield excavating machine.

Next, the trailing tunnel lining body 2B is constructed (step of constructing the trailing tunnel lining body). At this time, a trailing tunnel lining body 2B extending in the axial direction D2 is constructed at a position adjacent to the leading tunnel lining body 2A in the planned tunnel construction area. A shield excavator is also used in constructing the trailing tunnel lining 2B, and the trailing tunnel lining 2B is constructed while digging through the ground with the shield excavator.

Subsequently, as shown in FIGS. 2 and 3, the support member 20 is connected to the main girder 11 of the tunnel lining 2 (for example, the trailing tunnel lining 2B). Specifically, a part of the skin plate 12 of the segment 10 is removed and the removed skin plate 12 is removed (step of removing the skin plate). Then, the connecting portion 21c of the support member 20 is connected to the main girder 11 (step of connecting the support member). Specifically, the support member 20 is connected to the main girder 11 by fitting the plate-shaped portion 11b of the main girder 11 into the connecting portion 21c of the support member 20. Note that the connecting portion 21c is welded and fixed to the plate-like portion 11b while the plate-like portion 11b is inserted into the connecting portion 21c.

After the support member 20 is connected to the main girder 11 as described above, the reinforcing member 30 is connected to the support member 20 to support the main girder 11 (step of supporting the main girder). Specifically, the riser 33 with the stiffener 33d is fixed to the joint portion 23 with the bolt/nut fixing member B1. As shown in FIGS. 1 to 3, the joint plate 34 is joined to the support member 20 at an adjacent position in the axial direction D2, and the strut 31 is fixed to the upright 33 with bolts and nuts fixing members B3, thereby reinforcing the One end of the member 30 is connected to the support member 20 (step of connecting one end of the reinforcing member).

Subsequently, the support member 20 (supported member) is connected and the strut 31 is installed on the preceding tunnel lining body 2A as well. Note that a support member 20 (supported member) is installed on the preceding tunnel lining body 2A (main girder of the preceding tunnel lining body 2A). The end of the reinforcing member 30 on the opposite side from the trailing tunnel (trailing tunnel lining 2B) is connected to a supported member installed in the leading tunnel lining 2A. Then, the jacks 32 are installed to support the main girder 11 (step of supporting the main girder), and the reinforcing member 30 is completed.

The support member 20 and the reinforcing member 30 are installed, for example, sequentially from the top as the ground is excavated. Then, after the installation of the lowermost support member 20 and the reinforcing member 30 is completed, they are buried in concrete to construct the structure B (step of burying the reinforcing member). After that, the series of steps is completed.

Next, the effects of the reinforcing structure 1 and reinforcing method according to this embodiment will be explained. In the reinforcement structure 1, in the tunnel lining body 2, the plurality of main girders 11 are arranged so as to be lined up in the axial direction D2 of the tunnel, and each of the plurality of main girders 11 is arranged so as to extend in the circumferential direction D3 of the tunnel. has been done. The reinforcing structure 1 includes a support member 20 that supports the main girder 11 and a reinforcing member 30 that reinforces the support member 20, and the main girder 11 of the tunnel lining body 2 is supported by the reinforcing member 30.

The support member 20 is interposed between the main girder 11 and the reinforcing member 30, and when an external force is applied, the external force is transmitted from the reinforcing member 30 to the main girder 11 via the support member 20. Therefore, since the external force can be directly transmitted to the main girder 11 via the support member 20, the external force can be appropriately transmitted to the main girder 11 and deformation of the tunnel can be reliably suppressed.

As shown in FIGS. 2 and 3, the support member 20 includes a connecting portion 21c connected to the main girder 11, a connecting portion 22 extending in a direction crossing the connecting portion 21c, and a connecting portion 21c and the connecting portion 22. The connecting portion 21c is welded to the main girder 11, and the joint portion 23 is connected to the reinforcing member 30. Therefore, the strength of the support member 20 can be increased by the connecting portion 21c, the connecting portion 22, and the joint portion 23, so that external force can be appropriately transmitted to the main girder 11, and deformation of the tunnel can be suppressed more reliably.

The connecting portion 21c extends from the main girder 11 and is provided on a pair of upper and lower flanges (joint portions 21), and the connecting portion 22 may be a web that connects the pair of flanges. In this case, since a shaped steel such as an H-shaped steel can be used as the support member, it is possible to provide the support member 20 with high versatility.

The joint part 23 may be a joint plate fixed to the end of the connecting part 21c and the connecting part 22 on the opposite side to the main girder 11. In this case, since the supporting member 20 can be firmly connected to the reinforcing member 30 via the joint part 23, the external force can be more directly transmitted to the main girder 11 via the reinforcing member 30 and the supporting member 20, thereby making it stronger. The reinforcing structure 1 can be made as follows.

The connecting portion 21c may be a recessed portion into which the main beam 11 is inserted. In this case, the support member 20 can be attached to the main spar 11 by inserting the main spar 11 into the connecting portion 21c. Therefore, since the support member 20 can be easily attached to the main girder 11, the workability of tunnel construction can be improved.

In the reinforcement method according to the present embodiment, in each of the leading tunnel lining body 2A and the trailing tunnel lining body 2B, a plurality of main girders 11 are arranged in line in the axial direction D2 of the tunnel, and each main girder 11 are arranged so as to extend in the circumferential direction D3 of the tunnel. In this reinforcing method, the skin plate 12 is removed, the support member 20 is connected to the main girder 11, the reinforcing member 30 is connected to the supporting member 20, and the main girder 11 is supported by the reinforcing member 30. The support member 20 is interposed between the main girder 11 and the reinforcing member 30, and when an external force is applied, the external force is transmitted from the reinforcing member 30 to the main girder 11 via the support member 20.

Therefore, since the external force can be directly transmitted to the main girder 11 via the support member 20, the external force can be appropriately transmitted to the main girder 11 and deformation of the tunnel can be reliably suppressed. The support member 20 includes a connecting part 21c connected to the main girder 11, a connecting part 22 extending in a direction crossing the connecting part 21c, and a joint part 23 fixed to the connecting part 21c and the connecting part 22. The portion 21c is welded to the main girder 11, and the joint portion 23 is connected to the reinforcing member 30. Therefore, the strength of the support member 20 can be increased by the connecting portion 21c, the connecting portion 22, and the joint portion 23, so that external force can be appropriately transmitted to the main girder 11, and deformation of the tunnel can be suppressed more reliably.

In the step of installing the support member 20, the support member 20 may be installed on the main girder 11 by inserting the main girder 11 into the support member 20. In this case, since the support member 20 can be installed by inserting the support member 20 into the main girder 11, the support member 20 can be easily attached to the main girder 11. Therefore, the workability of tunnel construction can be improved.

The reinforcing method according to this embodiment may include a step of burying the reinforcing member 30 in concrete after the step of installing the reinforcing member 30. In this case, the concrete is buried in a state in which the leading tunnel lining body 2A and the trailing tunnel lining body 2B are reinforced by the reinforcing member 30. This makes it possible to strengthen the tunnel structure and complete the tunnel construction by burying the concrete. In other words, it is possible to eliminate the need to remove the reinforcing member 30, etc., thereby further improving the ease of tunnel construction.

(Second embodiment)
Next, a reinforcing structure 51 and a reinforcing method according to a second embodiment will be described with reference to FIG. 4. As shown in FIG. 4, a reinforcing structure 51 according to the second embodiment is provided in a steel plate concrete structure 60, as an example. For example, the steel plate concrete structure 60 is attached to a leading support structure 72 disposed on a leading tunnel lining 71 of a leading tunnel 70 and a trailing tunnel lining 81 of a trailing tunnel 80 constructed after the leading tunnel 70. It includes a disposed trailing support structure 82 and a concrete frame to be poured into the leading tunnel lining 71 and the trailing tunnel lining 81.

In the reinforcing structure 51, a steel plate concrete structure 60 is constructed by using a steel plate as an embedding formwork, enveloping the leading support structure 72 and the trailing support structure 82, and embedding concrete for the frame and hardening. The leading support structure 72 includes a plurality of leading steels 73 extending in a first direction A1, which is a direction in which the leading tunnel lining 71 and the trailing tunnel lining 81 are arranged in parallel, and a second mold steel 73 extending in a first direction A1, which is a direction in which the leading tunnel lining 71 and the trailing tunnel lining 81 are arranged in parallel. A plurality of shoring structures 74 extending in the direction A2 are provided. The trailing support structure 82 includes, for example, a plurality of trailing type steels 83. Further, the shoring 74 of the leading tunnel lining body 71 is connected and supported by a leading steel 73 that is a connecting member of the shoring 74 extending in the second direction A2. The steel plate concrete structure 60 is further bridged over and connected to a leading type steel 73 placed inside the leading tunnel lining 71 and a trailing type steel 83 placed inside the trailing tunnel lining 81. An intermediate type steel 110 is provided.

FIG. 5 is an enlarged cross-sectional view of the vicinity of the boundary between the leading tunnel 70 and the trailing tunnel 80. As shown in FIG. 5, the trailing tunnel lining 81 is obtained by cutting the leading tunnel lining 71 of the leading tunnel 70 and the filling material filled inside the leading tunnel lining 71 by the shield excavator. It is constructed while In parallel with this cutting, backfilling material 85 is injected and hardened backfilling material 85 is formed. The trailing tunnel lining body 81 includes a main girder 84 and a skin plate 86. A portion of the skin plate 86 has been removed. The reinforcing structure 51 includes a supporting member 90 connected to the main girder 84 of the trailing tunnel lining body 81 and a reinforcing member 100 connected to the supporting member 90. The support member 90 includes a connection part 91, a connection part 92, and a joint part 93, like the support member 20 described above.

The connecting portion 91 is welded to the main girder 84, and the connecting portion 92 extends from the connecting portion 91 in a direction crossing the connecting portion 91. A connecting portion 91 and a connecting portion 92 are fixed to the joint portion 93, and the joint portion 93 is connected to a reinforcing member 100. The reinforcing member 100 is a strut member that supports the main girder 84 of the trailing tunnel lining 81, and is supported by receiving reaction force from the shoring 74 arranged on the leading tunnel lining 71. A backfill material 85 is filled on the side of the leading tunnel lining body 71 of the main girder 84, and the support member 90 is installed with the backfill material 85 excavated (locally excavated) and removed at least in part. ing. For example, a filler 88 is filled between the backfill material 85 and the shoring 74. The filler 88 is, for example, air mortar. The reinforcing member 100 is installed with the filler 88 excavated (locally excavated) and at least a portion thereof removed.

Next, a tunnel reinforcing method according to the second embodiment will be described. As shown in FIG. 6, first, a preceding tunnel 70 is constructed. In construction of the preliminary tunnel 70, preliminary shield excavation is performed. In the advance shield excavation, the tunnel is constructed by the steel segment pieces 71b and the cuttable segment pieces 71c of the advance tunnel lining 71, and the tail clearance formed between each segment piece and the skin plate is filled with a backfilling material 85. Ru. Then, a preceding support structure 72 that supports the preceding tunnel lining body 71 is installed (step of providing a preceding support structure). At this time, concrete C is placed for internal support during the subsequent shield excavation, and filler material 88 (air mortar) is placed in the area R to be cut. Note that this filler material 88 is provided for retaining the ground during trailing shield excavation.

After constructing the preceding tunnel 70 as described above, a trailing tunnel 80 is constructed as shown in FIG. In construction of the trailing tunnel 80, trailing shield excavation is performed while cutting the cuttable segment piece 71c of the leading tunnel lining 71 and the filler material 88 (air mortar) in the area R to be cut. In the trailing shield excavation, a steel segment including the main girder 84 is constructed. At this time, the backfilling material 85 is filled as in the case of the preceding shield excavation. Specifically, the backfilling material 85 is inserted into the gap between the filling material 88 (air mortar) in the area R to be cut, the uncut portion of the cuttable segment piece 71c, and the trailing tunnel lining body 81 of the trailing tunnel 80. Filled.

After constructing the steel segments of the trailing tunnel 80 including the main girder 84, as shown in FIGS. 85 pot digging (local digging) is performed, and a part of the skin plate 86 is also removed (step of removing the skin plate). As a result, a space is formed in which the shoring 74 and the main girder 84 face each other. At this time, the partition wall or the preceding support structure 72 of the preceding tunnel lining body 71 is exposed. Then, the support member 90 is installed on the main girder 84 in the part where the skin plate 86 has been removed (step of installing the support member). At this time, for example, each support member 90 is attached to each main beam 84 by inserting the main beam 84 into each of the pair of upper and lower support members 90 . Next, one end of the reinforcing member 100 is connected to the supporting member 90 (a step of connecting one end of the reinforcing member). Then, the other end of the reinforcing member 100 is connected to the shoring 74, which is a supported member installed in the preceding tunnel 70, and the main girder 84 is supported by the reinforcing member 100 (step of supporting the main girder). Since the main girder 84 is supported via the shoring 74, reinforcing member 100, and support member 90 arranged inside the leading tunnel lining 71, deformation of the trailing tunnel lining 81 can be prevented. Therefore, after supporting the main girder 84, the skin plate 86 of the remaining trailing tunnel lining 81, the backfill material 85 of the trailing tunnel 80, and the filling material 88 inside the leading tunnel lining 71 are removed. , you can secure the work space after that. That is, after the trailing tunnel 80 is excavated and the trailing tunnel lining 81 is constructed, the filling material 88 (air mortar) of the leading tunnel 70 and the backfilling material 85 of the trailing tunnel are removed to secure a work space. In this case, the main girder 84 of the relevant portion of the trailing tunnel lining body 81 may be deformed due to lack of supporting force, but in the second embodiment, deformation of the trailing tunnel lining body 81 can be prevented and safety can be achieved. It is possible to secure a work space.

Then, as shown in Figures 9 and 10, the trailing support structure 82 is placed inside the trailing tunnel lining body 81 (step of placing the trailing support structure). The trailing support structure 82 placed at this time has a plurality of trailing steel bars 83 extending in the first direction A1 and a plurality of supports 87 extending in the second direction A2, similar to the leading support structure 72. Then, the intermediate steel bars 110 are placed between the trailing steel bars 83 and the leading steel bars 73 to connect them to the trailing steel bars 83 and the leading steel bars 73. The intermediate steel bars 110 and the trailing steel bars 83 are joint steel materials that connect a pair of leading steel bars 73 arranged along the first direction A1 to each other. At this time, for example, a pair of trailing steel bars 83 arranged in the second direction A2 are installed. After that, a plurality of shear steel materials and distribution steel materials that connect the pair of trailing steel bars 83 to each other are installed. Then, after installing air mortar in the trailing shield and pouring concrete into the interior of the leading tunnel lining 71 and the trailing tunnel lining 81, the reinforcement structure 51 is completed and the series of processes is completed. The supports 74, 74 located at both ends of the leading support structure 72 in the first direction A1 are supported by support members 90 provided on each of the main girders 84, 84 of the trailing tunnel linings 81, 81 of the trailing tunnel 80 located at both ends of the leading tunnel lining 71 of the leading tunnel 70, and reinforcing members 100 connected to the support members 90.

As described above, in the reinforcement structure 51 according to the second embodiment, the support member 90 is interposed between the main beam 84 and the reinforcement member 100. Therefore, when an external force is applied, the external force is transmitted from the reinforcing member 100 to the main girder 84 via the supporting member 90. Therefore, since the external force can be directly transmitted to the main girder 84 via the support member 90, the external force can be appropriately transmitted to the main girder 84 and the deformation of the leading tunnel 70 and the trailing tunnel 80 can be reliably prevented, as in the first embodiment. It can be suppressed.

In addition, in the tunnel reinforcement method according to the second embodiment, the support member 90 is connected to the main girder 84 of the trailing tunnel lining body 81 of the trailing tunnel 80 that is constructed after the leading tunnel 70 . is connected to one end of the reinforcing member 100. The other end of the reinforcing member 100 is connected to a supported member (shoring 74) installed in the preceding tunnel 70. Therefore, since the external force is transmitted to the main girder 84 via the supported member, the reinforcing member 100, and the support member 90, the external force can be appropriately transmitted to the main girder 84 and deformation of the tunnel can be reliably suppressed.

As shown in FIG. 5, the support member 90 has a connecting portion 91, a connecting portion 92, and a joint portion 93 connected to the main girder 84, and the connecting portion 91 is welded to the main girder 84, as described above. At the same time, the joint portion 93 is connected to the reinforcing member 100. Therefore, external force can be appropriately transmitted to the main girder 84 by the connection part 91, the connection part 92, and the joint part 93, and deformation of the tunnel can be suppressed more reliably.

In the second embodiment, the trailing tunnel 80 is constructed by cutting a part of the leading tunnel lining 71, and includes a leading support structure 72 that supports the cut leading tunnel lining 71. The method includes a step of providing. Therefore, the trailing tunnel 80 is constructed while part of the leading tunnel lining 71 is cut, and the cut leading tunnel lining 71 is supported by the leading support structure 72. Therefore, the cut portion of the preceding tunnel lining body 71 can be supported by the preceding support structure 72.

Various embodiments of the reinforcing structure and reinforcing method according to the present disclosure have been described above. However, the reinforcing structure and reinforcing method according to the present disclosure may be a combination of parts of various embodiments. That is, a portion of the first embodiment and a portion of the second embodiment described above may be combined.

Further, the reinforcing structure and reinforcing method according to the present disclosure can be further modified from the various embodiments described above. That is, the configuration, shape, size, number, material, and arrangement of each part of the reinforcing structure, as well as the content and order of the steps of the reinforcing method, can be changed as appropriate without departing from the gist of the claims. .

1... Reinforcement structure, 2... Tunnel lining body, 2A... Leading tunnel lining body, 2B... Trailing tunnel lining body, 4... Tunnel internal reinforcement shoring, 4b... First shoring, 4c... Second shoring 4d...Support part, 4f...Bar-shaped part, 4g...Support part, 4h...Bar-shaped part, 10...Segment, 11...Main girder, 11A...Middle main girder, 11B...Outer main girder, 11b...Plate-shaped part, 12 ...Skin plate, 13...Vertical rib, 20...Supporting member (supported member), 21...Joint part, 21b...End face, 21c...Connection part, 22...Connecting part, 22b...End face, 23...Joint part, 30...Reinforcement Member, 31...Strut beam (intermediate member), 31b...flange, 31c...web, 32...jack, 33...belly riser, 33b...flange, 33c...web, 33d...stiffener, 33f...first surface portion, 33g...first 2 side part, 34... Joint plate, 51... Reinforcement structure, 60... Steel plate concrete structure, 70... Preceding tunnel, 71... Preceding tunnel lining, 72... Preceding support structure, 73... Preceding type steel, 74... Shoring, 80 ... Trailing tunnel, 81... Trailing tunnel lining, 82... Trailing support structure, 83... Trailing type steel, 84... Main girder, 85... Backfill material, 86... Skin plate, 87... Shoring, 88... Filler, 90... Supporting member, 91... Connecting part, 92... Connecting part, 93... Joint part, 100... Reinforcing member, 110... Intermediate type steel, A... Opposing area, A1... First direction, A2... Second direction, B...Structure, B1, B2, B3...Bolt/nut fixing member, C...Concrete, D1...Vertical direction, D2...Axis direction, D3...Circumferential direction, D4...Opposing direction, R...Cutting area, S...Inner circumference surface.

Claims (8)

A tunnel lining reinforcement structure having main girders arranged at predetermined intervals in the axial direction of the tunnel and extending in the circumferential direction of the tunnel,
a support member connected to the main girder;
a reinforcing member connected to the supporting member;
Equipped with
The support member is
a connection part welded to the main girder;
a connecting portion extending from the connecting portion in a direction crossing the connecting portion;
The connecting portion and the connecting portion are fixed, and a joint portion is connected to the reinforcing member,
the main girder of the tunnel lining is supported by the reinforcing member;
Reinforced structure. The connecting portion extends from the main girder and is provided on a pair of upper and lower flanges,
The connecting portion is a web connecting the pair of flanges,
The reinforcing structure according to claim 1. The joint part is a joint plate fixed to an end of the connection part and the connection part on the opposite side to the main girder,
The reinforcing structure according to claim 1 or 2. The support member has a recess into which the main girder is inserted.
The reinforcing structure according to any one of claims 1 to 3. A method for reinforcing a tunnel lining body, the method comprising main girders arranged at predetermined intervals in the axial direction of a tunnel and extending in the circumferential direction of the tunnel, and a skin plate supported by the main girders,
connecting a support member to the main girder;
connecting a reinforcing member to the supporting member to support the main girder;
removing the skin plate;
Equipped with
The supporting member includes a connecting portion welded to the main girder, a connecting portion extending from the connecting portion in a direction crossing the connecting portion, and the connecting portion and the connecting portion being fixed to the reinforcing member. a joint portion to be connected;
Reinforcement method. A trailing tunnel constructed after the leading tunnel, which is arranged at a predetermined interval in the axial direction of the trailing tunnel, and is connected to a main girder extending in the circumferential direction of the trailing tunnel and the main girder. A method for reinforcing a trailing tunnel lining having a supported skin plate, the method comprising:
connecting a support member to the main girder of the trailing tunnel lining;
connecting one end of the reinforcing member to the supporting member;
connecting the other end of the reinforcing member to the preceding tunnel lining of the preceding tunnel or a supported member installed within the preceding tunnel to support the main girder;
removing the skin plate of the trailing tunnel;
Equipped with
The supporting member includes a connecting portion welded to the main girder, a connecting portion extending from the connecting portion in a direction crossing the connecting portion, and the connecting portion and the connecting portion being fixed to the reinforcing member. a joint portion to be connected;
Reinforcement method. The trailing tunnel is constructed by cutting a part of the leading tunnel lining,
a step of providing a preceding support structure that supports the cut preceding tunnel lining;
The reinforcing method according to claim 6. In the step of connecting the supporting members, the supporting member is supported by the main girder by inserting the main girder into the supporting member.
The reinforcing method according to any one of claims 5 to 7.

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