JP2009138387A - Segment, and construction method for widened section of tunnel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a segment which secures the strength of a joint section between a concrete skeleton provided in the lateral direction of a tunnel and a segment ring constituting the tunnel, for example, in the case of the widening of the tunnel, which is superior in workability and which dispenses with a meltdown operation etc., and a method for joining the segment and the concrete skeleton together. <P>SOLUTION: Side plates 5 are provided in the inward direction of the tunnel on both the long-side lateral sections of the segment 1, respectively. A perforated steel plate 9 is provided in parallel with the side plate 5. The perforated steel plate 9 is arranged in such a manner to be elongated to the inside of a stress transfer section 19. An embedded anchor 25 embedded in the concrete is provided in the stress transfer section 19. A vertical rib 7 is provided in a direction perpendicular to the side plate 5. The vertical rib 7 is made of concrete. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a method for constructing a segment and a tunnel widening portion, which are used at a joint portion between a casing provided on a side of a tunnel and a segment ring constituting the tunnel, for example, when widening a tunnel.

Conventionally, as a method of constructing a junction of an expressway having a tunnel, after providing a shield tunnel, a partial opening is provided in the shield tunnel of the junction, and a concrete frame is separately provided in the opening, A method of connecting a space formed by a frame and a tunnel is taken. It is necessary to process the segment at the joint portion with the concrete frame at the time of the joint construction with the concrete frame.

FIG. 8 is a perspective view showing a steel segment 60 that is conventionally used. The segment 60 mainly includes a skin plate 61, side plates 63, vertical ribs 65, joint plates 66, and the like. The skin plate 61 corresponding to the outer peripheral surface of the tunnel has a curved shape corresponding to the outer diameter of the tunnel. Side plates 63 are provided at both ends on the long side of the skin plate 61. Further, joint plates 66 are provided at both ends on the short side of the skin plate 61. That is, the skin plate 61, the side plate 63, and the joint plate 66 form a box shape.

Vertical ribs 65 are provided at regular intervals in the direction perpendicular to the side plates 63. The vertical rib 65 is a rib arranged in the axial direction of the tunnel, and resists the thrust of the shield jack and transmits a load acting on the skin plate 61 to the side plate 63. Moreover, the vertical rib 65 also has a role for suppressing buckling of the side plate 63 when the tunnel is completed.

The side plate 63 is provided with a joint hole 67 for joining the axial segments 60 of the tunnel. The joint plate 66 is provided with a joint hole 69 for joining the segment 60 in the circumferential direction. Accordingly, the segments 60 are connected to the circumferential direction and the axial direction of the tunnel, respectively. Here, each member is made of steel and joined by welding.

FIG. 9 is a view showing a processing state when the segment 60 is joined to an adjacent concrete frame. In order to join the segment 60 and the concrete frame, first, the skin plate 61 of the segment 60 is removed. By removing the skin plate 61, the segment 60 becomes a ladder shape, and the inside and outside of the tunnel are spatially connected.

Moreover, the center part (shaded part of FIG. 9) of the vertical rib 65 is cut | disconnected. Cutting is for avoiding interference with reinforcing steel bars embedded in the concrete frame. At this time, a part of the vicinity of the joint portion between the vertical rib 65 and the side plate 63 is left without being cut. This part functions as a shear connector 71 at the time of joining with the concrete casing, and maintains the shear joint strength between the concrete casing and the segment 60.

FIG. 10 is a view showing a state in which the processed segment 60 is embedded and joined in the concrete casing 73. As shown in FIG. 10, the segment 60 embedded in the concrete casing 73 is prevented from being displaced in the shearing direction between the segment 60 and the concrete casing 73 by the shear connector 71 and is reliably joined. As described above, the segment 60 used for the joint portion with the concrete housing 73 must be provided with the shear connector 71 in order to obtain joint strength. However, the vertical rib 65 is normally cut by fusing, and a seal member or the like is provided. Because there are combustible materials in the vicinity, it is dangerous and workability is also poor.

In addition to this, as the structure of the joint part between the concrete frame and the segment, for example, the segment tip and the reinforcing reinforcing bar before placing the concrete are arranged so as to intersect with each other, and the projecting portion from the edge of the top plate of the tunnel There is a joining structure of segments in which reinforcing reinforcing bars extend and extend until they reach the segment ring beyond the vertical line connecting the top of the segment ring and the center of the segment ring (Patent Document 1).

In addition, by connecting a reinforcing bar to form a RC member to a reinforcing bar joint attached to the hollow part of the steel shell, placing concrete to form the RC member, and filling the hollow part of the steel shell with concrete There is a joining structure of a steel shell and an RC member in which an RC member is integrally joined to the outside of the steel shell (Patent Document 2).
JP 2002-188398 A JP 2006-97317 A

However, in the joint structure of Patent Document 1, although the joint portion between the segment and the concrete frame can be enlarged, in order to ensure the joint strength between the segment and the concrete housing, the segment of the joint portion is the same as in the prior art. There is a problem that it is dangerous and workability is poor. Moreover, although the construction work of a reinforcing bar etc. is needed in a tunnel, there exists a problem that a work may be restrict | limited in a tunnel.

In the joint structure of Patent Document 2, it is necessary to weld a flange and a reinforcing rib to the inner surface of the web, and it is necessary to attach a reinforcing bar joint at a predetermined interval to connect the steel shell and the reinforcing bar of the RC member. For this reason, there exists a problem that a structure is complicated and an operation man-hour is required.

The present invention has been made in view of such a problem, and in the case of widening the tunnel, etc., while ensuring the strength of the joint portion between the concrete frame provided on the side of the tunnel and the segment ring constituting the tunnel. The purpose is to provide an excellent workability and an unnecessary segment such as a fusing operation.

In order to achieve the above-described object, the first invention includes a skin plate, a stress transmission portion provided on the short side of the skin plate, a side plate provided on the long side of the skin plate, and the side plate. And a steel plate having a plurality of holes provided substantially in parallel with each other.

The stress transmission part may be embedded with an anchor material inside the concrete, a screw may be provided inside the anchor material, or a vertical rib made of reinforced concrete may be provided substantially perpendicular to the side plate. Good.

According to the first invention, since the steel plate having a plurality of holes is provided in a direction perpendicular to the side plate, the holes of the perforated steel plate and the concrete are integrated, and the segment and the concrete can be provided without providing a separate shear connector or the like. There is no shear direction deviation, and no shear connector is required, and the vertical ribs are made of concrete, so there is no need to melt the vertical ribs when joining the segment and concrete, and the work is safe. In addition, by making the vertical ribs concrete, welding during installation of the vertical ribs on the segments can be omitted, so the cost can be reduced and the deformation of the segments due to welding does not occur, resulting in dimensional accuracy. And a segment with a simple structure can be provided.

2nd invention is the construction method of a tunnel widening part, Comprising: While arrange | positioning the 1st segment described in any one of Claims 1-3 in the junction plan part with a housing, it is in another site | part. Placing a normal second segment to construct a segment ring; excavating the first segment and a predetermined location outside the second segment; and entering the first segment into the excavated section. A method for constructing a tunnel widening portion, comprising: providing a frame so that the segment has an end portion; and removing the second segment of the excavated section.

According to the second invention, by using a segment having a steel plate having a plurality of holes at the joint with the concrete frame, the concrete wraps around the hole in the perforated steel plate, and the segment and the concrete frame are displaced. In order to prevent this, it is possible to provide a method for constructing a tunnel widening portion that does not require separate processing of a shear connector or the like.

ADVANTAGE OF THE INVENTION According to this invention, when expanding a tunnel etc., the segment etc. which are used for the junction part of the concrete frame provided in the tunnel side and the segment ring which comprises a tunnel can be provided.

Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a perspective view showing a segment 1 according to the present embodiment, and FIG. 2 is a plan view of the segment 1.

The segment 1 is mainly composed of a skin plate 3, side plates 5, vertical ribs 7, perforated steel plates 9, joint side plates 16 and the like.
That is, the side plate 5 and the joint portion side plate 16 are erected on the skin plate 3, the perforated steel plate 9 is provided in parallel to the side plate 5, and the vertical rib 7 is provided in parallel to the joint portion side plate 16. The skin plate 3 is a portion corresponding to the outer peripheral surface of the tunnel, and has a curved shape corresponding to the tunnel shape. The side plate 5 is a side wall portion of the segment 1 and forms a main portion that resists an external force acting on the tunnel. The vertical rib 9 resists the thrust of the shield jack and transmits a load acting on the skin plate 3 to the side plate 5.

The perforated steel plate 9 is a steel plate having a plurality of holes 10, and at the time of joining with a concrete frame, concrete wraps around the hole 10, prevents shear deviation from the concrete frame, and serves to reinforce the side plate 5. Also have. Here, the concrete frame is a frame provided in a widened portion of a tunnel such as a junction of an expressway, for example, and a part of a segment constituting the tunnel is embedded in the concrete frame.

As shown in FIG. 2, a stress transmission portion 19 is provided at one end of the segment 1, and a portion other than the stress transmission portion 19 becomes an embedded portion 21. The buried portion 21 is a portion buried in the concrete when joined to the concrete frame. The stress transmission part 19 that joins the segments in the circumferential direction of the tunnel is covered with the gibber steel plate 11 on the outside, and the inside is filled with concrete 17. The details of the stress transmission part 19 will be described later.

Side plates 5 are provided on both sides of the long side of the segment 1. A plurality of perforated steel plates 9 are provided in parallel with the side plates 5. The perforated steel sheet 9 is extended to the inside of the stress transmission part 19. Vertical ribs 7 are provided in the direction perpendicular to the side plates 5. The vertical ribs 7 are made of reinforced concrete. The structure of the vertical rib 7 will be described later.

A joint side plate 16 is provided at the end of the stress transmission portion 19. The joint part side plate 16 is provided with a joint hole 13 which is a through hole. The joining hole 13 is used when attaching a joining member such as a joint bolt when joining the segment 1 in the circumferential direction of the tunnel. The side plate 5 is provided with a joint hole 15. The joint hole 15 is for connecting segments in the tunnel axis direction. In addition, an injection hole 18 is provided in a portion corresponding to the stress transmission portion 19 of the side plate 5. The injection hole 18 is for injecting the concrete 17 into the stress transmission part 19.

3 is a cross-sectional view of the segment 1, FIG. 3A is a cross-sectional view taken along the line AA in FIG. 2, FIG. 3B is a cross-sectional view taken along the line BB in FIG. 2, and FIG. It is CC sectional drawing in 2. FIG.

2 is a cross section of a portion where the perforated steel sheet 9 is disposed. As shown in FIG. 3A, the stress transmission part 19 is filled with concrete 17. The stress transmission part 19 is surrounded by the skin plate 3, the gibber steel plate 11, the partition plate 14, and the joint part side plate 16, and is separated from the embedded part 21 by the partition plate 14. Further, a dowel 24 is provided on the inner surface of the skin plate 3 in the stress transmitting portion 19.

The perforated steel plate 9 extends from the embedded portion 21 through the partition plate 14 and extends into the concrete 17 of the stress transmission portion 19. The perforated steel sheet 9 provided in the concrete 17 is integrated with the concrete 17 without slipping because the concrete wraps around the hole 10 and solidifies. For this reason, the concrete 17 in the stress transmission part 19 can transmit stress to the skin plate 3 via the gibber 24 and also to the perforated steel sheet 9.

Reinforcing bars 23 are arranged in the portions where the vertical ribs 7 are provided. The reinforcing bar 23 may pass through the hole 10 of the perforated steel sheet 9 or may be provided with a separate through hole. In other words, the reinforcing bars 23 and the perforated steel plates 9 at the intersections are embedded in the concrete constituting the vertical ribs 7.

2 is a cross section of a portion where the joint hole 13 is provided. As shown in FIG. 3B, an embedded anchor 25 is provided in the concrete 17 at the joint hole 13 site. The buried anchor 25 is integrated with the concrete 17 by the anchor effect.

A hole is provided at the end of the embedded anchor 25, and a screw 27 is provided on the inner surface of the hole by tapping. Therefore, it is possible to join the adjacent segment with the screw 27 using a joint bolt or the like penetrating the joint hole 13.

The CC cross section in FIG. 2 is a cross section of the site | part in which the side plate 5 was provided. As described above, the side plate 5 is provided with the injection hole 18 and the joint hole 15. A perforated steel plate 9 may be welded to the inner surface of the side plate 5. In this case, the shear shift between the side plate 5 and the concrete frame can be further suppressed while being embedded in the concrete frame.

The force transmitted from the adjacent segment is transmitted in the segment 1 as follows. That is, when the segment 1 receives a tensile force from the adjacent segment, the tensile force from the joint bolt with the adjacent segment is transmitted to the skin plate 3 and the perforated steel plate 9 through the embedded anchor 25 and the concrete 17. It is transmitted from the skin plate 3 to the side plate 5.

Further, when the segment 1 receives a compressive force from the adjacent segment, the compressive force from the contact surface between the segment 1 and the adjacent segment is transmitted to the skin plate 3 and the concrete 17 to the perforated steel plate 9 and the side plate 5. Communicated. Further, when the segment 1 receives a bending force from the adjacent segment, the stress is transmitted by the above-described tension and compression transmission mechanism.

Next, the manufacturing method of the segment 1 is demonstrated. 4 and 5 are diagrams showing a method for manufacturing the segment 1. FIG. 4 (a) shows a state in which the side plate 5 and the perforated steel plate 9 are joined to the skin plate 3, and FIG. 4 (b) shows a partition. The figure which shows the state which provided the board 14 and the burying anchor 25, FIG.4 (c) is a figure which shows the state which joined the jebel steel plate 11. FIG. 5 is a view showing a construction method of the vertical rib, FIG. 5 (a) is a view showing a state in which a reinforcing bar 23 is provided, and FIG. 5 (b) is a view showing a state in which a formwork 29 is provided. FIG. 5C is a view showing a state in which the mold 29 is filled with concrete.

As shown in FIG. 4A, the side plate 5 and the perforated steel plate 9 are joined to the skin plate 3. The perforated steel plate 9 and the skin plate 3 may be joined by simple spot welding or temporary welding. This is because when the perforated steel sheet 9 is embedded in the concrete 17, the concrete 17 enters the hole 10, and stress is directly transmitted between the concrete 17 and the perforated steel sheet 9. A plurality of dowels 24 are joined to a portion of the skin plate 3 corresponding to the stress transmission portion 19.

Next, as shown in FIG. 4B, the partition plate 14 and the joint portion side plate 16 are joined to the skin plate 3 or the side plate 5. As described above, the joint hole 13 is provided in the joint side plate 16 in advance. An embedded anchor 25 is joined to the joint hole 13 portion of the joint part side plate 16. As described above, the embedded anchor 25 has a hole in advance, and a screw 27 is provided in the hole.

Next, as shown in FIG. 4 (c), the dowel steel plate 11 is joined to a portion surrounded by the skin plate 3, the side plate 5, the partition plate 14, and the joint portion side plate 16. A plurality of dowels are provided in advance on the inner surface of the dowel steel plate 11. Thereafter, concrete 17 is placed in a space surrounded by the skin plate 3, the side plate 5, the partition plate 14, the joint portion side plate 16 and the gibber steel plate 11 from the injection hole 18 provided in the side plate 5.

Next, a method for constructing the vertical rib 7 will be described. First, as shown in FIG. 5A, the reinforcing bars 23 are arranged perpendicular to the side plates 5 at the construction site of the longitudinal rib 7. As described above, the reinforcing bar 23 may penetrate the hole 10 of the perforated steel sheet 9 at the intersection with the perforated steel sheet 9 or may separately provide a through hole in the perforated steel sheet 9.

Next, as shown in FIG. 5 (b), a form frame 29 is provided on the skin plate 3 at the construction site of the vertical rib 7. The formwork 29 may be a thin steel plate. The formwork 29 may be left behind after the construction of the longitudinal rib 7 in order to reinforce the longitudinal rib 7.

Next, as shown in FIG. 5C, concrete 8 is placed in the mold 29. The concrete 8 embeds the reinforcing steel 23 and the perforated steel sheet 9 at the intersecting portion.

As described above, according to the segment 1 according to the present embodiment, since the perforated steel plate 9 is provided in parallel with the side plate 5, the concrete casing in which the segment 1 is embedded without providing a shear connector or the like, There is no deviation from segment 1. That is, since concrete wraps around the hole and solidifies when the concrete frame is constructed, the concrete frame and the segment 1 can be easily integrated.

Also, since the vertical ribs 7 are made of concrete and there is no need to process shear connectors, stud gibbles, etc., there is no need to perform processing such as fusing of the vertical ribs at the joints with the concrete frame, and the work is safe. It is. In addition, since no shear connector or stud gibber is required, there is no interference during the construction of the reinforcing steel bars embedded in the concrete frame. That is, the perforated steel sheet 9 does not interfere with the reinforcing reinforcing bars except for the thick part, so that the workability is good and the degree of freedom of the reinforcing reinforcing bar construction is improved.

Moreover, by using the vertical ribs 7 made of concrete, the welding between the vertical ribs 7 and the side plates 5 and the skin plate 3 can be simplified, thereby deforming due to the welding at the time of manufacturing the segment 1. Can be prevented.

In addition, since the embedded anchor 25 having the screw 27 is provided in the stress transmission portion 19 and integrated with the concrete 17, the stress from the adjacent segment is transferred to the skin plate 3, the side plate 5, and the embedded via the embedded anchor 25 and the concrete 17. It can be transmitted to the perforated steel sheet 9. For this reason, a joint plate or the like is not required, and it is not necessary to firmly weld the joint plate to the skin plate 3 or the like. Therefore, the number of manufacturing steps can be reduced, and deformation due to welding can be prevented.

Next, the tunnel widening process using the segment 1 will be described. FIGS. 6A to 6F are diagrams showing each process of the construction.

First, as shown to Fig.6 (a), while providing the earth retaining wall 31 from the ground 30 of the upper part of a tunnel construction part, the inside is excavated. A support 33 is provided inside the retaining wall 31 as necessary. In addition, a ground improvement 35 is applied to the base of the retaining wall 31 in advance.

Next, as shown in FIG. 6B, a tunnel is constructed by a shield machine, and segment rings 37a and 37b are provided. At this time, the segment 1 is arranged in the segment of the part to be joined to the concrete frame. In addition, the segment of other parts can use a normal steel segment, a synthetic segment, etc.

Next, as shown in FIG. 6C, the ground between the segment rings 37a and 37b, in which the internal support 39 is provided in the segment rings 37a and 37b, is excavated. A support 33 is provided in the excavation part as needed.

Next, as shown in FIG. 6 (d), the skin plate of the segment at the position facing the excavated site (part A in the figure) is removed. By removing the skin plate, the segment becomes a ladder shape, and the inside of the segment rings 37a and 37b and the excavation part are spatially connected. In this state, concrete is placed in a mold (not shown) so as to embed the segment 1, and a lower bottom plate 41 is provided.

Next, as shown in FIG. 6 (e), while removing the support 33 and the internal support 39, concrete is placed on a mold (not shown) to provide a side wall 45 and an upper bottom plate 43, and a concrete frame 49 is provided. Build up. In addition, the concrete frame 49 (the lower bottom plate 41, the side wall 45, and the upper bottom plate 43) is provided with reinforcing reinforcing bars and the like in advance before placing the concrete and is embedded in the concrete. In this state, a pavement 57 or the like is formed in the segment ring 37, for example, a road or the like is constructed.

Next, as shown in FIG.6 (f), the segment between the segment ring 37a and the concrete frame 49 is removed, all the support works 33 and the internal support works 39 are removed, and the excavation part is backfilled. When the road works and the like in the segment rings 37a and 37b are completed, the tunnel is completed.

FIG. 7 is an enlarged view of part B of FIG. 6 (f), and shows a state in which the segment 1 is embedded in the concrete frame 49. A general segment 51 disposed above the segment 1 is connected to the stress transmission portion 19 of the segment 1. The embedded portion 21 of the segment 1 is embedded in the concrete frame 49. As described above, in this state, the skin plate 3 of the segment 1 is removed. Although the removal segment 53 was arrange | positioned under the segment 1, as above-mentioned, it is removed after concrete frame 49 construction.

As described above, according to the tunnel widening work using the segment 1 according to the present embodiment, the segment 1 can be easily made of concrete without any special processing or construction such as construction of a shear connector or stud gibber. The housing 49 can be joined. That is, the concrete wraps around the hole of the perforated steel sheet 9 in the buried portion 21 and solidifies, so that no shear deviation occurs between the perforated steel sheet 9 and the concrete, and stress transmission between the perforated steel sheet 9 and the concrete is prevented. Since the part 19 can transmit stress, the segment 1 and the concrete frame 49 can transmit stress smoothly.

Moreover, since the vertical rib 7 is made of concrete, when the segment 1 is embedded, it can be integrated with the concrete frame and the vertical strength of the segment 1 can be maintained.

As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

For example, although the embedded anchor 25 is used for the stress transmission portion 19 as a joint portion with a segment adjacent in the tunnel circumferential direction, a normal joint plate may be firmly welded to the skin plate to form the joint portion. Further, the stress transmission part 19 may be provided not only on one end of the segment 1 but on both sides.

The perspective view which shows the segment 1. FIG. The top view of the segment 1. FIG. It is sectional drawing of the segment 1, (a) is AA sectional drawing in FIG. 2, (b) is BB sectional drawing in FIG. 2, (c) is CC sectional drawing in FIG. It is a figure which shows the segment 1 manufacturing method, (a) is a figure which shows the state which joined the side plate 5 and the perforated steel plate 9 to the skin plate 3, (b) shows the state which provided the partition plate 14 and the embedded anchor 25. The figure which shows the state which joined FIG. It is a figure which shows the construction method of the vertical rib 7 of the segment 1, (a) is a figure which shows the state which provided the reinforcing bar 23, (b) is a figure which shows the state which provided the formwork 29, (c) is a formwork The figure which shows the state which filled concrete in 29. FIG. The figure which shows the state which excavated the ground and provided the earth retaining wall 31 and the ground improvement 35. FIG. The figure which shows the state in which the segment ring 37 was provided by the shield machine. The figure which shows the state which provided the internal support work 39 in the segment ring 37, and excavated between the segment rings 37. FIG. The figure which shows the state which removed the skin plate of the one part segment which comprises the segment ring 37, and provided the lower bottom plate 41. FIG. The figure which shows the state which provided the side wall 45 and the upper bottom plate 43, and constructed the concrete frame 49. FIG. The figure which shows the state which removed the support work and backfilled the excavation part. It is the B section enlarged view of Drawing 6 (f), and is a figure showing the state where segment 1 and concrete frame 49 were joined. The perspective view which shows the segment 60. FIG. The figure which shows the processing state of the segment 60 in the site | part joined with a concrete frame. The figure which shows the state by which the segment 60 was joined with the concrete frame 73. FIG.

Explanation of symbols

1 ... Segment 3 ... Skin plate 5 ... Side plate 7 ... Vertical rib 9 ... Perforated steel plate 10 ... Hole 11 ... Giber steel plate 13 ... Joint hole 14 ... Partition plate 15 ... Joint hole 16 ......... Joint side plate 17 ... Concrete 18 ... Injection hole 19 ... Stress transmission part 21 ... Embedded part 23 ... Reinforcing bar 24 ... ... Givel 25 ......... Embedded anchor 27 ......... Screw 29 ......... Formwork 30 ......... Ground 31 ......... Domestic wall 33 ......... Support work 35 ......... Ground improvement 37 ......... Segment ring 39 ......... Inside Supporting work 41 ………… Lower bottom plate 43 ………… Upper bottom plate 45 ……… Side wall 47 ……… Pavement 49 ……… Concrete frame 51 ……… General segment 53 ……… Removal segment 60 ……… Segment 61 …… ... Skin plate 63 ... Side plate 65 ... Vertical rib 66 ... Plate 67 ......... joint hole 69 ......... joining hole 71 ......... Shear connectors 73 ......... concrete skeleton

Claims (4)

Skin plate,
A stress transmission part provided on the short side of the skin plate;
A side plate provided on the long side of the skin plate;
A steel plate having a plurality of holes provided substantially parallel to the side plate;
The segment characterized by comprising. The stress transmission part is
The segment according to claim 1, wherein an anchor material is embedded in the concrete, and a screw is provided in the anchor material. The segment according to claim 1 or 2, wherein longitudinal ribs made of reinforced concrete are provided substantially perpendicular to the side plate. A method for constructing a tunnel widening section,
The step of arranging the first segment according to any one of claims 1 to 3 in a portion to be joined to the housing and constructing a segment ring by arranging a normal second segment in another part When,
Drilling a predetermined location outside the first segment and the second segment;
Providing a housing with an end in the first segment to the excavated section;
Removing the second segment of the excavated section;
A method for constructing a tunnel widening section, comprising:

Images