Tunnel lip structure

Abstract

To provide a tunnel lip structure having good workability without lengthening the construction period while using a steel lip having a lower rigidity than a reinforced concrete structure in the tunnel lip structure in which the lip connects a general section having a circular cross section with a widening section.SOLUTION: In a tunnel lip structure 50 in which a lip 30 connects a general section 10 with a circular cross section and a widening section 20 in a tunnel formed by multiple segments, the lip 30 is a steel shell having a skin plate 32 that closes a gap between the general section 10 and the widening section 20, a main girder 31 that extends in the radial or approximately radial direction of the tunnel and is fixed in an upright position relative to the skin plate 32, and a joint plate 34 that abuts against an inner surface of the widening section 20 and is fixed in an upright position relative to the skin plate 32. The joint plate 34 and the inner surface of the widening section 20 are bolted together, and the skin plate 32 and general section 10 are bolted together.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a tunnel bottom structure. [Background technology]

[0002] For example, when constructing road tunnels in urban areas where soft ground is prevalent, open cut construction methods are generally used, but open cut construction methods have inherent issues such as noise and vibration during construction and traffic restrictions. In addition, since the space under roads in urban areas is congested with buried objects such as multiple subways and utility tunnels, the installation depth of new tunnels tends to be deep, and deepening the installation depth directly leads to increased construction costs. Against this background, the number of cases in which the shield method is used for the construction of road tunnels is increasing. In the construction of road tunnels, emergency exits and emergency parking areas are generally constructed by cutting open a tunnel with a circular cross section (including a roughly circular cross section with a horseshoe shape) underground. In this way, by cutting open part of the general part of the circular cross section to the side, a certain section of widened section is constructed in the tunnel axial direction, and at the start and end of the widened section, hem sections are constructed to connect the general part and the widened section in, for example, the radial direction of the tunnel.

[0003] The above-mentioned bottom section is made of cast-in-place reinforced concrete (RC) structure. One of the reasons for this is that construction errors often occur when constructing the general section and the widening section, and even manufacturing errors can occur in the segments, so by constructing the bottom section of cast-in-place reinforced concrete structure, it is possible to connect the general section and the widening section with a bottom section shaped in a way that can absorb these various errors. In contrast, for example, when constructing a hem using a steel shell, after constructing the general section and the widening section, it is necessary to measure the distance between them in detail on-site and then fabricate the steel shell in a factory based on the results of the measurement. This means that the construction period may be longer than when constructing a hem using a reinforced concrete structure, which is another reason why a hem using a reinforced concrete structure is used.

[0004] On the other hand, there are structural issues with the bottom part of the reinforced concrete structure. In other words, for example, in a case where the soil covering is relatively shallow and the ground is soft and easily affected during earthquakes, if the general section and the widening section are connected by a highly rigid hem made of reinforced concrete, large cross-sectional forces are likely to occur in the linings (e.g., steel segments) of the general section and the widening section near the hem due to the difference in deformation during an earthquake between the general section and the widening section, which have different shapes and diameters. This makes it necessary to increase the component specifications of these steel segments, leading to increased construction costs.

[0005] For these reasons, it is desirable to have a tunnel lip structure that connects the general section with a circular cross-section to the widening section, which uses steel lips that have less rigidity than reinforced concrete structures, while not lengthening the construction period and being easy to construct.

[0006] Here, Patent Document 1 proposes a reinforcement structure for an underground structure that reinforces the underground structure provided to secure a space to be used as a work area when constructing a large-diameter tunnel in a part of an existing tunnel. In this reinforcement structure, the underground structure is composed of a ring-shaped structure constructed in the circumferential direction outside the planned construction area of ​​the large-diameter tunnel, and a front side wall and a rear side wall constructed at both ends of a cylindrical body made of the ring-shaped structure and through which the existing tunnel penetrates, and one end and the other end of a tendon extending in the axial direction of the existing tunnel are installed at a predetermined position in the existing lining of the existing tunnel, in a range joined to the front side wall, and at a predetermined position in a range facing the natural ground. Both the front side wall and the rear side wall are concrete walls installed at each end of a cylindrical body consisting of two ring-shaped bodies, and their outer edges are joined so as to be integral with the inner surfaces of the ring-shaped bodies. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2021-75931 Summary of the Invention [Problem to be solved by the invention]

[0008] The reinforcement structure for the underground structure described in Patent Document 1 also has the above-mentioned structural issues because the front and rear side walls through which the existing tunnel passes are both concrete walls.

[0009] The present invention aims to provide a tunnel lip structure in which a bottom section connects a general section with a circular cross section to a widening section, which has good workability without prolonging the construction period while using a steel bottom section which has less rigidity than a reinforced concrete structure. [Means for solving the problem]

[0010] In order to achieve the above object, one aspect of the tunnel bottom structure according to the present invention is as follows: A tunnel rim structure in which a rim connects a general section having a circular cross section and a widening section in a tunnel formed by a plurality of segments, The hem portion is A skin plate that closes a gap between the general portion and the widened portion; A main girder extending in a radial direction or a substantially radial direction of the tunnel and fixed in an upright position relative to the skin plate; a joining plate that abuts against an inner peripheral surface of the widened portion and is fixed in an upright position relative to the skin plate; The joining plate and the inner peripheral surface of the widening portion are joined by bolts, The skin plate and the general portion are joined by bolts.

[0011] According to this embodiment, the joint plate of the bottom part made of steel shell is abutted against the inner peripheral surface of the widening part and bolted, and any part of the skin plate of the bottom part is bolted to the general part, so that the restraint of the general part and the widening part, which has a smaller rigidity than the reinforced concrete structure, is reduced, and it is possible to suppress the generation of large cross-sectional forces in both parts, and the deformation difference during an earthquake between the general part and the widening part, which have different shapes and diameters, can be effectively absorbed by the flexible structure of the bottom part. Furthermore, since both ends of the bottom part made of steel shell are bolted to both the general part and the widening part, the joint structure of both can be a pin structure, so that no bending moment is generated at the joint in terms of design. In addition, since one side of the steel shell body (the joining plate) is joined to the widening section, and an arbitrary location of the other side of the steel shell body (the area on the general section side of the skin plate) is joined to the general section, even if there is a construction error or manufacturing error between the general section and the widening section, it is not necessary to manufacture the steel shell body after on-site survey (it is possible to manufacture the steel shell body in advance), and good workability is achieved without prolonging the construction period. Furthermore, since the main girders extend in the radial or approximately radial direction of the tunnel, they can withstand the axial force resulting from the difference in deformation between the general section and the widening section during an earthquake, and can transmit this axial force to the general section and the widening section via the main girders.

[0012] Another aspect of the tunnel bottom structure according to the present invention is as follows: A shaped steel material is welded to the skin plate, The present invention is characterized in that the connecting plate at the end of the general section and the structural steel material are connected by bolts via the skin plate.

[0013] According to this aspect, the shaped steel material welded to the skin plate is bolted to the joining plate at the end of the general part via the skin plate, so that the general part and the bottom part can be joined more firmly and watertightness can be ensured. Here, examples of the shaped steel material include channel steel, angle steel, H-shaped steel, etc.

[0014] In another aspect of the tunnel bottom structure according to the present invention, The bolt holes provided in the widening portion are precast bolt holes that are pre-opened in a factory, The bolt holes provided in the general portion and the bolt holes provided in the bottom portion are field-installed bolt holes that are opened at the field.

[0015] According to this aspect, the bolt holes in the widening section are precast bolt holes, while the bolt holes in the general section and the bottom section are on-site constructed bolt holes. This means that the bottom section made of a steel shell does not need to be manufactured after the general section and widening section have been constructed in a factory, etc., and can be manufactured in advance. Even if there are construction or manufacturing errors in the general section and the widening section, the bottom section made of a steel shell can be smoothly and reliably bolted to them.

[0016] In another aspect of the tunnel bottom structure according to the present invention, The bottom portion is formed of a plurality of bottom portion divided steel shells that are divided in the circumferential direction, The bottom split steel shell includes the skin plate, the main girder, and the joint plate, The segment joints between adjacent split bottom steel shells are formed by bolting the main girders at the ends of both split bottom steel shells.

[0017] According to this embodiment, since the bottom portion is formed of a plurality of bottom portion divided steel shells which are divided in the circumferential direction, the bottom portion can be constructed efficiently, and it is preferable that the bottom portion can be constructed from the inside of the already constructed general portion and the widening portion (inside the tunnel).

[0018] Another aspect of the tunnel bottom structure according to the present invention is as follows: A plurality of main girders are welded to the skin plate at intervals, The present invention is characterized in that sub-beams connecting the main girders are welded to the skin plate.

[0019] According to this aspect, the sub-beams connecting the main girders are welded to the skin plate, thereby preventing buckling of the main girders.

[0020] Another aspect of the tunnel bottom structure according to the present invention is as follows: At least a general section seal provided at the segment joint of the general section, a bottom section seal provided at the segment joint of the bottom section, and an enlarged section seal provided at the segment joint of the enlarged section are continuous, The connection regions of the general portion seal and the hem portion seal are set on the inside so that the separation between the ends can be ensured taking into account the installation error between the general portion and the widened portion.

[0021] According to this aspect, at least in the segment joint, the general section seal provided at the segment joint of the general section, the bottom section seal provided at the segment joint of the bottom section, and the widened section seal provided at the segment joint of the widened section are continuous, so that a continuous water-stopping structure can be formed from the general section to the bottom section and from the bottom section to the widened section. In addition, the connection areas of both the general part seal and the bottom part seal are set on the inside so that the distance between the ends can be ensured while taking into account installation errors, thereby making it possible to maintain a continuous water-stopping structure from the general part to the bottom part even if installation errors occur. Here, the connection region of the general section seal is spaced from the end of the general section (the side surface on the inner side of the tunnel) by, for example, changing the height of the seal line extending laterally inward in the connection region. On the other hand, the connection region of the bottom section seal is spaced from the end of the bottom section (the end surface on the inner side of the tunnel) by, for example, bending the seal line extending vertically (radially) at a position where it joins the general section seal and extending it laterally. This space can be set to, for example, about 10 mm to 20 mm.

[0022] In another aspect of the tunnel bottom structure according to the present invention, The bottom split steel shell that is installed last is a K-segment bottom split steel shell, in which at least one of the segment joints at the left and right ends has a first tapered surface; A B segment bottom divided steel shell body having a second tapered surface that abuts against the first tapered surface is disposed on at least one of the left and right sides of the K segment bottom divided steel shell body, At least one of the bolt holes at corresponding positions provided on the joint plate of the K segment bottom divided steel shell body and the joint plate of the B segment bottom divided steel shell body is an elongated hole; A bolt is inserted through one side of the interconnected bolt holes and is fastened by a nut on the other side, Between the joining plate having the long hole and the head or nut of the bolt, a washer is interposed, the washer having a first through hole extending in a thickness direction thereof and through which the bolt passes, In the long hole, a gap where the bolt does not exist is blocked with a filler, The washer is characterized in that it further includes a second through hole extending in the thickness direction and into which the filler is injected, and a through hole connecting the second through hole and the long hole.

[0023] According to this embodiment, at least one of the bolt holes at corresponding positions on the joining plates of the adjacent K segment bottom split steel shell body and B segment bottom split steel shell body is a long hole, and bolts are inserted into both bolt holes to join the two, resulting in a segment joining structure that can absorb errors including surveying errors, construction errors, and segment manufacturing errors. Furthermore, a washer is interposed between the joining plate having a long hole and the head of the bolt or the nut, and this washer has a second through hole into which the filler is injected and a through hole that connects the second through hole and the long hole, and the filler injected through these through hole and through hole blocks the gap in the long hole, thereby ensuring that the gap in the long hole is closed. Effect of the Invention

[0024] According to the tunnel bottom structure of the present invention, in which the bottom connects the general section with a circular cross-section to the widening section, a steel bottom having less rigidity than a reinforced concrete structure can be used, while still achieving good workability without prolonging the construction period. [Brief description of the drawings]

[0025] [Figure 1] FIG. 2 is a perspective view of an example of a bottom structure of a tunnel according to an embodiment. [Diagram 2] FIG. 2 is an enlarged view of part II in FIG. [Diagram 3] FIG. 2 is a vertical cross-sectional view of an example of a bottom structure of a tunnel according to an embodiment. [Figure 4] FIG. 2 is a perspective view showing an example of a B segment bottom divided steel shell body and a K segment bottom divided steel shell body. [Figure 5A] FIG. 11 is a perspective view of an example of a washer, as viewed from a non-contact surface side that does not contact a joining plate. [Figure 5B] FIG. 11 is a perspective view of an example of a washer, as viewed from the side of a contact surface that comes into contact with a joining plate. [Figure 6] FIG. 13 is a longitudinal sectional view showing a segment joint between a B segment bottom split steel shell body and a K segment bottom split steel shell body. [Figure 7] FIG. 13 is a diagram illustrating a water-stopping structure in a bottom structure of a tunnel according to an embodiment. [Figure 8] 1 is a diagram illustrating a method for designing various components of a tunnel bottom structure according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, a tunnel structure according to an embodiment will be described with reference to the accompanying drawings. In this specification and the drawings, substantially the same components are designated by the same reference numerals to avoid redundant description.

[0027] [Tunnel bottom structure according to the embodiment] An example of a bottom structure of a tunnel according to an embodiment will be described with reference to FIGS. Here, Fig. 1 is a perspective view of an example of a bottom structure of a tunnel according to an embodiment, Fig. 2 is an enlarged view of part II in Fig. 1, and Fig. 3 is a longitudinal sectional view of an example of a bottom structure of a tunnel according to an embodiment. Fig. 4 is a perspective view of an example of a B-segment bottom divided steel shell body and a K-segment bottom divided steel shell body, and Figs. 5A and 5B are respectively a perspective view of an example of a washer seen from a non-contact surface side not in contact with a joint plate and a contact surface side in contact with a joint plate. Fig. 6 is a longitudinal sectional view of a segment joint of a B-segment bottom divided steel shell body and a K-segment bottom divided steel shell body, and Fig. 7 is a diagram for explaining a water-stopping structure in a bottom structure of a tunnel according to an embodiment.

[0028] As shown in Fig. 1, a tunnel bottom structure 50 has a structure in which a general section 10 having a circular cross section formed by a plurality of segments is connected to a widened section 20 by a bottom 30. Here, Fig. 1 shows only the bottom 30 side of the general section 10 extending in the axial direction of the tunnel, and similarly, only the bottom 30 side of the widened section 20 is shown. This tunnel is, for example, a road tunnel, and the widened section 20 becomes an emergency exit or emergency parking zone that is constructed by cutting open a partial section of the general section 10.

[0029] The general section 10 is a steel shell formed by joining multiple segments (general section divided steel shell 10B) in the circumferential direction of the tunnel via segment joints to form a steel shell ring 10A, and by joining multiple steel shell rings 10A in the axial direction of the tunnel via ring joints.

[0030] The general divided steel shell 10B that forms the steel shell ring 10A comprises a pair of main girders 11, a skin plate 12 welded to the outer peripheral ends of the pair of main girders 11, and a plurality of vertical ribs 13 that connect the pair of main girders 11 at a predetermined interval in the circumferential direction.

[0031] The widening section 20 constructed in a section of the general section 10 is a steel shell formed by joining a plurality of steel shell arc-shaped rings 20A, each of which is made up of a plurality of segments (widening section divided steel shells 20B) that bulge out laterally from the general section 10, via ring joints in the axial direction of the tunnel. The steel shell arc-shaped ring 20A is formed by joining a plurality of widening section divided steel shells 20B in the circumferential direction of the tunnel via segment joints.

[0032] The widening section divided steel shell 20B that forms the steel shell arc-shaped ring 20A comprises a pair of main girders 21, a skin plate 22 welded to the outer peripheral ends of the pair of main girders 21, and a plurality of vertical ribs 23 that connect the pair of main girders 21 at a predetermined interval in the circumferential direction.

[0033] The bottom section 30 is a steel shell formed by a plurality of bottom section divided steel shells 30A, 30B, 30C, and each bottom section divided steel shell 30A, 30B, 30C has a skin plate 32 that closes the gap between the general section 10 and the widening section 20, a pair of main girders 31 that extend in the radial or approximately radial direction of the tunnel and are welded to the skin plate 32 in an upright position, and a plurality of small beams 33 that are similarly welded to the skin plate 32 and connect the pair of main girders 31 together. Furthermore, a shaped steel material 35 (channel steel in the illustrated example) is welded to the joint area of ​​the skin plate 32 with the main girders 11 at the end of the general section 10, and a joint plate 34 is welded to the joint area with the inner flange 21a of the widening section 20.

[0034] Since the main girder 31 extends in the radial or approximately radial direction of the tunnel, the main girder 31 can withstand the axial force resulting from the difference in deformation between the general section 10 and the widening section 20 during an earthquake, and can transmit the axial force to the general section 10 and the widening section 20 via the main girder 31.

[0035] In addition, the sub-beams 33 connecting the main girders 31 are welded to the skin plates 32, thereby preventing the main girders from buckling.

[0036] As shown in FIG. 3, bolt holes 31a are drilled in the main girders 31 of each bottom section split steel shell 30A, 30B, 30C at the factory, and adjacent main girders 31 each serve as a joint plate of the segment joint, and a bolt is inserted into the corresponding bolt hole 31a of both to form the segment joint.

[0037] As shown in FIG. 1, the widening section 20 is provided at a diagonally downward position of the general section 10, and the bottom section 30 is constructed by installing an A-segment bottom separate steel shell body 30A, installing a B-segment bottom separate steel shell body 30B, and then inserting a K-segment bottom separate steel shell body 30C into the gap between the B-segment bottom separate steel shell body 30B and its opposite end.

[0038] In this way, since the bottom section 30 is formed by a plurality of bottom section divided steel shells 30A, 30B, 30C, the weight of the steel shells to be hung during construction can be reduced as much as possible, improving construction efficiency. In addition, the bottom section divided steel shells 30A, 30B, 30C can be installed in sequence by utilizing the internal space of the general section 10 and the widening section 20 that have already been constructed, which is preferable because the bottom section 30 can be constructed inside the tunnel.

[0039] As shown in Figure 3, an inner flange 21a is welded to the inside (bottom 30 side) of the main girder 21 at the end of the widening section 20 that is joined to the bottom 30, and a reinforcing rib 21b that spans both the main girder 21 and the inner flange 21a is welded to both of them.

[0040] The inner flange 21a is provided with precast bolt holes 27 that are drilled in advance at the factory.

[0041] On the other hand, in the general portion 10, a field installation bolt hole 16 is made at a position where the general portion 10 is joined to the bottom portion 30.

[0042] The construction of the bottom portion 30 is carried out by joining the bottom portion 30, which is a steel shell, to the general portion 10 and the widened portion 20 after at least the areas of the general portion 10 and the widened portion 20 facing the bottom portion 30 have been constructed.

[0043] When installing each bottom section split steel shell 30A, 30B, 30C, the joining plate 34 at one end is abutted (metal touch) against the inner surface of the inner flange 21a of the widening section 20 extending in a direction perpendicular to the radial direction, and the outer surface of the other end side of the skin plate 32 is abutted against the main girder 11 at the end of the general section 10 extending in the radial direction, and temporarily fixed.

[0044] The inner flange 21a is provided with precast bolt holes 27 fabricated in a factory, and in order to construct the main girder 11 with the on-site installed bolt holes 16, as shown in Figure 3, with the bottom section split steel shells 30A, 30B, 30C in the above-mentioned temporary fixed position, on-site installed bolt holes 37 are constructed at positions corresponding to the precast bolt holes 27 in the connecting plate 34, and on-site installed bolt holes 36 are constructed in the skin plate 32 and the channel steel 35 at positions avoiding the main girder 11 (joint plate) and vertical ribs 13 of the general section 10.

[0045] After the on-site installed bolt holes 37, 36 are installed on site, bolts can be inserted into the interconnected precast bolt holes 27 and 37, and the precast bolt holes 16 and 36, and the nuts can be tightened to join the bottom section split steel shells 30A, 30B, 30C to the general section 10 and the widening section 20.

[0046] In this way, the bottom-section split steel shells 30A, 30B, and 30C are installed on the sides of two components in different directions, namely, the inner flange 21a of the widening section 20 extending in a direction perpendicular to the radial direction and the main girder 11 at the end of the general section 10 extending in the radial direction. This makes it possible to install the bottom-section split steel shells 30A, 30B, and 30C without being affected by construction errors of the general section 10 and the widening section 20.

[0047] Furthermore, by installing on-site bolt holes 37, 36 in the connecting plate 34, the skin plate 32 and the channel steel 35 and connecting them to the corresponding precast bolt holes 27 in the inner flange 21a and the on-site bolt holes 16 in the main girder 11, it becomes possible to bolt these to the bottom section split steel shells 30A, 30B, 30C without being affected by construction errors in the general section 10 and the widening section 20.

[0048] The construction of the general section 10 and the widening section 20 often results in the above-mentioned construction errors, and the segments forming the general section 10 and the widening section 20 may also have manufacturing errors. Therefore, when connecting the general section 10 and the widening section 20 through a bottom section while absorbing these various errors, a bottom section of reinforced concrete structure cast in situ has been generally used, which allows the shape of the bottom section to be freely changed to a certain extent. If the bottom section is a steel shell made of steel segments, it is necessary to survey the bottom section construction area after the general section 10 and the widening section 20 are constructed in order to deal with the above-mentioned various errors, and to manufacture the steel segments in a factory based on the survey results. Therefore, a bottom section of reinforced concrete structure cast in situ has been conventionally used, since there is a risk of extending the construction period, including the construction of the bottom section.

[0049] However, in a structure in which the general section 10 and the widening section 20 are joined at the bottom of a high-rigidity reinforced concrete structure, excessive bending moments are likely to occur at the joint ends of the two sections due to the difference in deformation between the general section 10 and the widening section 20 during an earthquake, making it necessary to apply steel segments with specifications capable of withstanding this excessive bending moment, which leads to increased construction costs.

[0050] In order to solve the above problems, the bottom portion 30 in the illustrated example has a lower rigidity than the bottom portion of a reinforced concrete structure, and by applying a steel shell consisting of flexible steel segments, the occurrence of excessive bending moment at the joint end is eliminated, and the application of a steel shell capable of withstanding excessive bending moment is no longer necessary, thereby preventing an increase in construction costs.

[0051] Furthermore, since both ends of the bottom portion 30, which is made of a steel shell, are bolted to both the general portion 10 and the widened portion 20, the joint structures of both can be pin structures, so that no bending moment is generated at the joints in terms of design.

[0052] Furthermore, even if there are construction errors in the general section 10 or the widening section 20, the steel shell can be installed while absorbing the construction errors. Therefore, the bottom section divided steel shells 30A, 30B, and 30C can be manufactured in the factory in parallel with the construction of the general section 10 and the widening section 20, so there is no risk of the construction period being extended.

[0053] As shown in FIG. 4, the segment joint between the B segment bottom divided steel shell body 30B and the K segment bottom divided steel shell body 30C is formed by bringing the second tapered surface of the main girder 31 of the B segment bottom divided steel shell body 30B into surface contact with the first tapered surface of the main girder 31 of the K segment bottom divided steel shell body 30C, and aligning the multiple (three in the illustrated example) bolt holes 31a (round holes) opened in the main girder 31 of the B segment bottom divided steel shell body 30B with the multiple (three in the illustrated example) bolt holes 31b (long holes) opened in the main girder 31 of the K segment bottom divided steel shell body 30C. Even if there is a construction error, since one of the bolt holes is the long hole 31b, a bolt can be inserted into the mutually communicating round hole 31a and long hole 31b to form a bolt joint. This makes it possible to form a segment joint at the long hole 31b even if there is a construction error or manufacturing error. If it is not necessary to make the bolt holes 31b elongated, they may be round holes.

[0054] As shown in Figure 6, at the segment joint between the K segment bottom divided steel shell body 30C and the B segment bottom divided steel shell body 30B, a washer 40 (long hole gap closing washer) that closes the long hole 31b is arranged on the side of the long hole 31b in the main girder 31 (joint plate).

[0055] As shown in Figures 5A and 5B, washer 40 has a first through hole 44 extending in its thickness direction and through which bolt 19A passes, a second through hole 46 extending in the thickness direction and into which filler material is injected, and a conductive hole 47 that connects second through hole 46 and long hole 31b (the gap in which no bolt is present).

[0056] The washer 40 for blocking the gap of a long hole further has a seat groove 45 having a larger diameter than the first through hole 44 around the first through hole 44 on the contact surface 41 that contacts the joining plate 31 having the long hole 31b, and the contact surface 41 further has an air vent hole 48 that communicates with a long hole not shown.

[0057] As shown in Figure 5B, when a filler such as mortar is injected in the Y1 direction from the second through hole 46 in the non-contact surface 42 of the washer 40, the injected filler flows through the conductive hole 47 in the contact surface 41 that contacts the joining plate 31, as shown in Figure 5B, and fills in the gap where no bolt is present in the long hole 31b provided in the joining plate 31 (not shown) in the Y2 direction, thereby blocking the gap.

[0058] Furthermore, when the filler material is filled into the gaps of the long holes 31b, the air that was present in the gaps is released in the Y3 direction through the air vent hole 48, allowing the gaps to be filled sufficiently with the filler material. When the gaps are completely filled with the filler material, the filler material is discharged in the Y3 direction from the air vent hole 48, and therefore it is possible to confirm that the gaps have been completely filled with the filler material by visually checking the discharge of the filler material.

[0059] Furthermore, a relatively large diameter seat groove 45 is provided around the first through hole 44 in the abutment surface 41, so that the gap in the long hole 31b can be effectively filled with the filler 49, as shown in Figure 6. This is preferable because the filler 49 can be reliably filled into the gap in the long hole 31b, particularly when the viscosity of the filler 49 is high or when the gap is formed on only one side of the long hole 31b.

[0060] As shown in Figure 7, general section seals 18A, 18B provided at the segment joints of the general section 10, bottom section seals 38A, 38B provided at the segment joints of the bottom section 30, and widened section seals 28A, 28B provided at the segment joints of the widened section 20 are continuous, as well as the circumferential seal of the outer main girder of the general section 10 (not shown) and the circumferential seal between the inner flange of the widened section 20 and the joining plate of the bottom section 30 (not shown).

[0061] In the connection regions 39 of both the general portion seal 18B and the bottom portion seal 38B, the end separation (for example, about 10 mm to 20 mm) is set on the inside, taking into consideration installation errors between the general portion 10 and the widened portion 20. As a result, even if installation errors occur between the general portion 10 and the bottom portion 30 or between the general portion 10 and the widened portion 20, a continuous watertight structure from the general portion 10 to the bottom portion 30 can be maintained.

[0062] Next, an example of a method for designing a tunnel bottom structure according to the embodiment will be described with reference to FIG.

[0063] The skin plate 32 of the bottom portion 30 is subjected to an external load P1, which includes normal lateral soil and water pressure and backfill injection pressure during construction.

[0064] In addition, due to the difference in deformation between the general portion 10 and the widened portion 20, an axial force N1 may occur in the main girder 31.

[0065] The main girder 31 is designed as a member capable of resisting the bending moment and axial force that may be generated by the external load P1 and axial force N1 acting on the skin plate 32.

[0066] Furthermore, a repulsive force P2 of the seal material is generated in the joint region between the bottom portion 30 and the widened portion 20. The inner flange 21a is designed as a member capable of resisting the bolt tensile force due to the axial force N1 and the repulsive force P2 of the seal material.

[0067] The bolt 19A in this joining region is designed as a member capable of resisting the shear force due to the external load P1, and the tensile force due to the axial force N1 and the repulsive force P3 of the sealing material.

[0068] The joint plate 34 is designed as a member capable of resisting the bolt shear force due to the external load P1 and the bolt tensile force due to the axial force N1 and the sealing material repulsive force P2.

[0069] The welding (fillet welding) of the reinforcing rib 21b to the main girder 21 is designed as a weld that can withstand the shear force due to the axial force N1 and the repulsive force P2 of the sealing material.

[0070] Furthermore, in the joining region between the general portion 10 and the bottom portion 30, the channel steel 35 is designed as a member capable of resisting the bending moment due to the external load P1 and the repulsive force P3 of the sealing material.

[0071] The bolt 19A in this joining region is designed as a member capable of resisting the tensile force due to the external load P1 and the sealing material repulsive force P3, and the shear force due to the axial force N1.

[0072] The weld (fillet weld) of the channel steel 35 to the main girder 31 is designed as a weld capable of withstanding the shear force due to the external load P1 and the sealing material repulsion force P3, and the shear force due to the axial force N1.

[0073] In addition, the present invention is not limited to the configuration shown here, and may be implemented in other embodiments in which other components are combined with the configurations and the like of the above-mentioned embodiment. In this regard, the present invention may be modified within the scope of the gist of the present invention, and may be appropriately determined according to the application form. [Explanation of symbols]

[0074] 10:General section 10A: Steel shell ring 10B:General partial steel shell body 11: Main girder 12: Skin plate 13: Vertical ribs 16: On-site bolt hole 18A, 18B: General section seal 19A: Bolt 19B: Nut 20: Widening section 20A: Steel shell arc ring 20B: Widening section split steel shell 21: Main girder 21a: Inner flange 21b: Reinforcement rib 22: Skin Plate 23: Vertical ribs 27: Precast bolt hole 28A, 28B: Widened section seal 30: Bottom 30A: A segment bottom split steel shell (bottom split steel shell) 30B: B segment bottom split steel shell (bottom split steel shell) 30C: K-segment bottom split steel shell (bottom split steel shell) 31: Main girder (joint plate) 31a: Segment joint bolt hole (round hole) 31b: Segment joint bolt hole (long hole) 32: Skin plate 33: Small beam 34: Joint plate (joint plate) 35: Shaped steel (channel steel) 36, 37: On-site bolt holes 38A, 38B: Bottom seal 39: Connection area 40: Washer (long hole gap blocking washer) 41: Contact surface 42: Non-contact surface 44: First through hole 45: Seat groove 46: Second through hole 47: Conduction hole 48: Air vent hole 49: Filling material 50: Tunnel hem structure

Claims

1. A tunnel rim structure in which a rim connects a general section having a circular cross section and a widening section in a tunnel formed by a plurality of segments, The hem portion is A skin plate that closes a gap between the general portion and the widened portion; A main girder extending in a radial direction or a substantially radial direction of the tunnel and fixed in an upright position relative to the skin plate; a joining plate that abuts against an inner peripheral surface of the widened portion and is fixed in an upright position relative to the skin plate; The joining plate and the inner peripheral surface of the widening portion are joined by bolts, A tunnel bottom structure, characterized in that the skin plate and the general section are bolted together.

2. A shaped steel material is welded to the skin plate, 2. A tunnel bottom structure as described in claim 1, characterized in that the joint plate at the end of the general section and the shaped steel material are bolted together via the skin plate.

3. The bolt holes provided in the widening portion are precast bolt holes that are pre-opened in a factory, 2. A tunnel structure according to claim 1, wherein the bolt holes in the general section and the bolt holes in the bottom section are field-installed bolt holes opened at the site.

4. The bottom portion is formed of a plurality of bottom portion divided steel shells that are divided in the circumferential direction, The bottom split steel shell includes the skin plate, the main girder, and the joint plate, 2. The tunnel bottom structure according to claim 1, wherein the segment joints between adjacent split steel shells are formed by bolting the main girders at the ends of the split steel shells.

5. A plurality of main girders are welded to the skin plate at intervals, 5. A tunnel bottom structure according to claim 1 or 4, characterized in that a sub-beam connecting the main girders is welded to the skin plate.

6. At least a general section seal provided at the segment joint of the general section, a bottom section seal provided at the segment joint of the bottom section, and an enlarged section seal provided at the segment joint of the enlarged section are continuous, The tunnel lip structure described in claim 4, characterized in that the connection areas of both the general section seal and the lip section seal are set on the inside so that the separation of the ends can be ensured taking into account the installation error of the general section and the widening section.

7. The bottom split steel shell that is installed last is a K-segment bottom split steel shell, at least one of the segment joints at the left and right ends of which is provided with a first tapered surface; A B segment bottom divided steel shell body having a second tapered surface that abuts against the first tapered surface is disposed on at least one of the left and right sides of the K segment bottom divided steel shell body, At least one of the bolt holes at corresponding positions provided on the joint plate of the K segment bottom divided steel shell body and the joint plate of the B segment bottom divided steel shell body is an elongated hole; A bolt is inserted through one side of the interconnected bolt holes and is fastened by a nut on the other side, Between the joining plate having the long hole and the head or nut of the bolt, a washer is interposed, the washer having a first through hole extending in a thickness direction thereof and through which the bolt passes, In the long hole, a gap where the bolt does not exist is blocked with a filler, The tunnel rim structure described in claim 6, characterized in that the washer further includes a second through hole extending in the thickness direction and into which the filler material is injected, and a through hole connecting the second through hole and the long hole.

Images