JP4707410B2 - Tunnel invert, invert block, and invert construction method using the invert block - Google Patents

Description

  The present invention relates to an invert built inside a tunnel such as a shield tunnel or a common groove (in the present application, it generally means a cylindrical structure), improving the manufacturability, improving the economy, and improving the workability. Therefore, the present invention relates to an invert block member manufactured as a precast member, an invert construction method using the block member, and the like.

  As the representative invert, an invert (see FIG. 1) used for a tunnel constructed by a shield method will be described below as an example.

  The invert 3 built inside the tunnel 1 is provided mainly for the purpose of ease of work such as inspection and repair after the tunnel construction. Specifically, in rainwater storage pipes that are used as primary reservoirs for rainwater during heavy rains, people and heavy machinery are used for maintenance inspections and repairs after tunnel construction, and when sedimented mud is removed after heavy rain. As a movement route, in common grooves such as electric wires, gas pipes, and waterworks, it is generally provided as a movement route for humans and machines during work such as wiring inside a tunnel, maintenance inspection, and repair work.

  On the other hand, in sewer tunnels, as a countermeasure to prevent misunderstandings, steps, leaks, and corrosion on the inner surface of the tunnel constructed by the shield method, a secondary lining is used to cover the inner surface of the primary lining tunnel with cast-in-place concrete. It was never set up.

  However, in recent years, due to improvements in shield method technology, there have been almost no mistakes, steps or leaks at the stage of primary lining, and in order to reduce construction costs or shorten the construction period, a corrosion protection layer has been added to the segment in advance. A method of providing a secondary lining and eliminating the secondary lining has been adopted, and in that case, it has become necessary to provide an invert for the purpose of maintenance inspection and repair after the construction.

  A method generally used as an invert construction method is a spot casting method in which a formwork is assembled and concrete is cast after tunnel lining. However, this method has the following drawbacks.

(1) It takes a lot of labor and cost to install the mold, demold and cast concrete.

(2) A curing period is required for placement at the site. (In general, it requires a two-stage construction method in which only the central horizontal part of Invert 3 shown in FIG. 1 is assembled, placed and cured, and then placed and cured on the end formwork. (A lot of labor, time and cost are required.)

  On the other hand, for a small-diameter shield tunnel, in recent years, a technique has been developed that integrates a tunnel lining segment and an invert to make a precast member unnecessary for on-site curing (for example, see Patent Document 1). . However, this also has the following disadvantages.

(1) Due to the special shape, it costs a lot to produce the segment. In particular, the sharp curve portion is often manufactured with a synthetic segment in which the outer shell is covered with an iron plate and filled with concrete, or a medium-filled concrete steel segment, which is expensive.

(2) Difficult to handle due to special shape.

(3) Since the position of the segment with invert is limited, there are restrictions on how to assemble the segments when making meandering corrections or during curve construction.

  In addition, in Patent Document 2, an engagement groove in the tunnel circumferential direction is provided on the inner peripheral surface of the tunnel lining segment, an engagement protrusion is provided on the lower surface of the invert block, and the invert blocks are further connected. Also, there is disclosed a method in which an engaging groove and an engaging protrusion formed on the front and rear surfaces of the invert block are fitted and installed.

  However, in this case as well, since the segment shape is special like the invention described in Patent Document 1, not only the cost of the segment is high, but also the cross-sectional defect of the engaging groove needs to be considered.

  Further, since the inverted blocks are arranged so as to straddle the joints between the segments, it is very difficult to install the tunnel blocks in the tunnel curve portion and to deal with errors and differences between the segments that are unavoidable in design.

Patent Document 3 and Patent Document 4 disclose one in which both ends of a plate-like invert block are fixed to a segment with bolts or anchors directly or via a bracket. However, when the tunnel cross section becomes large, it becomes difficult to support at both ends of the flat block, and the block weight per one becomes large, so it is not easy to carry in the block.
Japanese Patent Laid-Open No. 2001-288992 Japanese Patent Laid-Open No. 11-287095 JP 2004-183273 A JP 2004-204583 A

  The present invention is intended to solve the problems in the prior art as described above, and can be installed easily and efficiently on the site without using a specially shaped segment, and the built invert has excellent stability on the inner surface of the tunnel. Provide an invert that can be applied to curved parts, can easily cope with misunderstandings and errors on the inner surface of the tunnel, has excellent manufacturability and economy, and can be easily managed as a precast member, and its construction method The purpose is that.

The invention according to claim 1 is formed by connecting a plurality of invert blocks each having an invert provided below the inner surface of the tunnel cross section composed of a plurality of segments into a plurality of shapes divided in the tunnel circumferential direction and the tunnel axial direction. The invert block has a plurality of leg portions in contact with the inner surface of the segment on the lower surface, and allows rotation in the vertical plane at the connecting portion between adjacent invert blocks in the tunnel circumferential direction. Between the invert blocks adjacent to each other in the direction, a gap is provided between the male and female joints that are fitted to each other to allow rotation in a horizontal plane in the fitted state, and the inner surface of the segment without the lower surface of the invert block direct contact with, and in contact with the inner surface of the segments of the plurality of legs is a fulcrum And it is characterized in and.

  The material of the invert block is not particularly limited as long as the necessary strength and durability as an invert can be ensured, and the same reinforced concrete, unreinforced concrete, cellular concrete, combination of steel and concrete as the lining segment. In addition to these, reinforced plastics, ceramics, and the like may be used, and any combination thereof is also possible.

  In the circumferential direction of the tunnel, the rotation in the vertical plane at the connection between adjacent invert blocks is allowed not only for various errors, but also for the primary cover, especially in the curved section of the tunnel. Considering the manufacturability and economics of the segment of the work, it is normal that the change of the tunnel cross section is unavoidable in terms of design, and it is not economical to prepare various invert blocks. The tunnel circumferential direction is also divided into a plurality of blocks so that these can be installed without difficulty according to the segments constituting the inner circumferential surface of the tunnel.

  Also, when deciding the size of the invert block that is divided into multiple parts in the tunnel axis direction and the circumferential direction, whether it is by machine or considering the use of human power, it is set to a size and weight that are easy to handle accordingly can do.

  Rotation in the horizontal plane (preferably in the horizontal plane and in the vertical plane) in the fitted state with a gap between the male and female joints that fit together between adjacent invert blocks in the tunnel axial direction. The movement is allowed mainly considering the correspondence to the curved portion, particularly the sharp curved portion. If it is possible to transfer stress between male and female joints and make it possible to construct an invert with the minimum number of invert blocks using play, economic efficiency, management and handling are easy. This is also advantageous.

  For example, when the tunnel is divided into three in the circumferential direction, the end invert blocks on both sides in the circumferential direction have the same shape, and two types of invert blocks, the center invert block and the end invert block, are used, and the curved portion and / or straight portion of the tunnel It is also possible to continue the inversion in the tunnel axis direction.

  In addition, the presence of legs makes it easier to secure the fulcrum than the case where the segment and the invert block are in direct contact with the curved surface, and the stability is good, making it possible to cope with manufacturing errors, construction errors, and other irregularities. Cheap. In addition, the leg assumed in the present invention is generally extremely short. However, as will be described later in the embodiment, the length of the leg is set in the same formwork when corresponding to the tunnel diameter and other design conditions. Since it is easy to manufacture only by changing, it also reduces the cost of the formwork.

  A second aspect of the present invention limits the case where the invert blocks adjacent to each other in the tunnel circumferential direction are connected via a knuckle joint.

  Conventionally, knuckle joints are used for joints between segments that connect segments in the circumferential direction in shield tunnels, but the connecting ends are in contact with uneven curved surfaces, and joint bolts such as bent bolts must be used. Can be connected, and has a structure that allows slight rotation on a curved surface.

  Therefore, by using the knuckle joint between the invert blocks adjacent to each other in the tunnel circumferential direction, basically the inversion blocks need only be arranged side by side, and the operation becomes very easy.

  In addition, by allowing slight rotation at the knuckle joint, it can easily cope with tunnel construction errors and deformations, unevenness between the segments and bending at sharp curves, and to tunnels with different diameters. This is advantageous when considering the application of.

  In the invert according to claim 1 or 2, the case where the filler is filled in the gap between the inner surface of the segment and the lower surface of the invert block and / or the invert blocks is limited.

  When diverting without converting the invert to a permanent structure, it is only necessary to connect the invert blocks side by side, but when used as part of a completed tunnel, the structural stability can be improved by filling the filler. In the case where it is required to increase the water shielding performance, it is conceivable to fill with a filler having a high water-stopping property.

  Depending on the purpose, the use of mortar-based materials and various resin-based grout materials can be considered as fillers. For the purpose of water-stopping and preventing leakage, rubber, plastic, foamable materials, etc. You may use a water stop material and an outflow prevention material.

  According to a fourth aspect of the present invention, in the invert according to the first, second, or third aspect, the invert block is divided into three invert blocks of a central invert block and end invert blocks on both sides in the tunnel circumferential direction. Thus, the case where a part or the entire surface of the central invert block sandwiched between the end invert blocks forms a bottom surface of a groove extending in the tunnel axis direction of the invert is limited.

  In the present invention, the number of divisions in the circumferential direction and the axial direction of the tunnel depends on the diameter of the tunnel, but it is desirable that a single block is easy to handle in terms of weight, and that the block dimensions can be handled with as few types as possible. . Moreover, as a cross-sectional shape of the invert, a groove is often provided in the central portion located on the lower surface of the tunnel, and treated water is flowed to the construction, used for cleaning, or low in the sewage tunnel after construction. In the water level state, sewage and the like flow through the groove portion of the invert.

  As for the tunnel axis direction, it is desirable not to make each inverted block straddle between segments so that it does not become unstable due to the influence of misunderstandings, etc. The length of 1. In the case of a general shield tunnel, it is usually appropriate to match the segment width or ½ thereof. Moreover, it is preferable to position a leg part inside the side surface of an invert block.

  The invert according to the present invention is suitable for installation in a curved part of a tunnel, but can also be used for a straight part of a tunnel. In this case, it is easy to produce a manufacturing error of a segment, construction error, deformation of a segment ring, etc. While it has a merit of high workability and economy while coping with it, when applied to a curved part, particularly a sharply curved part, a dramatic effect can be expected compared to conventional invert.

  In that case, the case where the invert according to the present invention is used only for the curved portion and the case where the invert is used not only for the curved portion but also for the straight portion can be considered. Furthermore, even in the case where the latter is used together with the straight portion, the rotation in the vertical plane between the invert blocks adjacent in the tunnel circumferential direction and the horizontal plane between the invert blocks adjacent in the tunnel axial direction are also possible. By allowing rotation in (preferably in the horizontal plane and in the vertical plane), the same invert blocks can be used for the straight portion and the curved portion, and the minimum number of invert blocks can be used.

  As a result, since the types and quantities of molds or molds that are generally expensive can be reduced, manufacturing costs can be reduced, and management and handling can be facilitated.

The invert block according to claim 5 has a shape in which the invert provided below the inner surface of the tunnel cross section composed of a plurality of segments is divided into a plurality of sections in the tunnel circumferential direction and the tunnel axial direction, and the tunnel cross section is configured on the lower surface . A plurality of legs in contact with the inner surface of the segment, and at least one side in the circumferential direction of the tunnel is formed with a joint that allows rotation in a vertical plane at a connection portion with an adjacent invert block. axially both sides, between the invert block adjacent to each other in the tunnel axis, have fitted case made to have a clearance from one another, the male joint of the convex shape to permit rotation in the horizontal plane and / or a invert block concave female joint is formed, the inner surface and the invert of the segments when configuring a tunnel section Without locking the underside of direct contact, is characterized in that said plurality of legs is in contact with the inner surface of the segment becomes a fulcrum.

  A sixth aspect of the present invention is the invert block according to the fifth aspect, wherein a concave curved surface or a convex curved surface constituting a knuckle joint that is in contact with adjacent invert blocks and curved surfaces is formed on at least one side in the tunnel circumferential direction. Limited.

  Claims 5 and 6 define one aspect of the invert block used for the invert according to claims 1 to 4, and have a function of the knuckle joint in the tunnel circumferential direction and a clearance in the tunnel axial direction. The function of the joint is as described above.

  In an invert block according to claim 5 or 6, in an invert block according to claim 5 or 6, the inside of the male joint is penetrated between the male joint and / or the female joint formed on both sides in the tunnel axial direction, and in the tunnel axial direction. The case where the continuous through-hole is formed is limited.

  Since invert is continuous in the tunnel axis direction, by providing a through hole in the invert block that is continuous in the tunnel axis direction, for example, optical fibers, electric wires, and various other cables can be passed through this through hole. Thus, it is possible to eliminate these exposures that cause problems in appearance and installation space after completion.

Further, in this case, there is a merit that it is easy to ensure the continuity and water stoppage of the through-hole portion continuous in the tunnel axis direction because the through-hole penetrates the inside of the male joint in the fitting male-female joint portion. .

  In the invert construction method according to claim 8, the tunnel lining invert block according to claim 5, 6 or 7 is connected to the tunnel circumferential direction and the tunnel axial direction below the inner surface of the tunnel cross section composed of a plurality of segments. However, it is characterized by being installed sequentially.

  The construction of the invert of the present invention is possible for an existing tunnel or a tunnel that has been completed in a certain section, but it is used for installation of transfer equipment such as materials and discharged soil during construction of the tunnel, traveling of vehicles, etc. In order to build a tunnel, it is necessary to build an invert.

  In the case of the present invention, the construction of the invert only requires laying the invert blocks and aligning the joints, so compared with the case where the precast block is attached to a spot-mounted invert or a specially shaped segment or a bracket fixed to the segment. The work is greatly simplified and the workability is excellent.

  A ninth aspect of the present invention is the invert construction method according to the eighth aspect, in which a case where the filler is filled into the gap between the inner surface of the segment and the lower surface of the invert block and / or the invert blocks is limited.

  The filler is as described for claim 3.

According to the present invention, since the invert blocks can be continuously installed, the construction time can be greatly reduced, and an invert excellent in unity and stability can be constructed as an invert.

  Since it is possible to rotate the tunnel in the circumferential direction at the joint, and to rotate horizontally and vertically with respect to the tunnel axis direction, it can easily cope with construction errors such as misalignment of the segments and openings. Also suitable for installation.

  Further, by injecting filler into the gap between the tunnel inner surface and the gap between the joints, it is possible to obtain a smooth surface without a step as in the case of spotting.

  The tunnel segment does not require a special shape for invert installation, and can be applied to tunnels using ordinary segments, so the construction cost of the entire tunnel can be reduced.

  FIG. 2 shows an embodiment of the present invention in which the invert 3 is divided into three in the tunnel circumferential direction (the number of divisions may be larger), and the longitudinal direction of the tunnel 1 is a segment 2 (circumferential dividing line is not shown). The invert blocks 11 and 21 divided by the width of () may be installed (or a larger number of divisions).

  Single figures are shown in FIG. 3 (central invert block 11) and FIG. 4 (end invert block 21).

  The central invert block 11 is provided with a male joint 13 on the left side and a female joint 14 on the right side (male on the right side and female on the left side), facing the joint surface in the longitudinal direction (tunnel axis direction). Has a similar joint. This is so considered that even if the invert block 11 is rotated 180 degrees around the vertical axis, the joint arrangement of the same shape is obtained.

  In addition, the joints 13 and 14 have a width that gradually decreases and gradually increases in the longitudinal direction. The joints 13 and 14 are easy to be removed when removed from the mold, and serve as guides when assembled on site. The circumferential joint joined to the end invert block 21 is a male knuckle joint 12 in which circular convex portions are continuously provided in the longitudinal direction.

  Two pairs of leg portions 15 are provided on the bottom surface of the product on the inner side of the joint surface, and are used as locations in contact with the inner surface of the tunnel. As shown in the figure, the corners of the joint surface have a chamfered shape (chamfered portion 19) to prevent chipping.

  The end invert block 21 in FIG. 4 also has a joint in the longitudinal direction that is male and female on the left and right and has a shape that gradually decreases or increases in diameter in the longitudinal direction, and rotates 180 degrees around the vertical axis. Thus, it can be used for both the left and right invert blocks 21 and can be installed smoothly as a guide during assembly.

  In the illustrated example, the thickness of the end invert block 21 is thicker on the center invert block 11 side (inner side) and thinner on the opposite side (outer side), and the male joint 23a and the female located on the inner side accordingly. The diameter of the joint (not shown in the figure) is large, and the diameters of the male joint 23b and the female joint 24b located on the outside are small.

  With respect to the small-diameter end invert block 21 (which can be transported by human power), the joints 23 and 24 on the center side may be provided without providing joints on the left and right as shown in FIG.

  The circumferential joint is a female knuckle joint 22 in which a circular concave portion having an arc radius slightly larger than the arc radius of the male knuckle joint 12 of the central invert block 11 is provided continuously in the longitudinal direction. Even if the inner surface of the tunnel 1 does not have a predetermined radius of curvature due to the deformation, the leg portions 15 and 25 are brought into contact with the inner surface of the tunnel 1 due to the rotation of the knuckle portion, and the structure is unlikely to be lifted or rattle. Further, two pairs of leg portions 25 are provided on the bottom surface in the same manner as the central invert block 11, and chamfering processing (chamfered portion 29) is applied to the corner portion of the joint surface.

  In the above embodiment, the circumferential joint of the central invert block 11 is the male knuckle joint 12, and the joint surface side of the end invert block 21 with the central invert block 11 is the female knuckle joint 22. On the contrary, the former circumferential joint may be a female knuckle joint, and the joint surface side with the latter central invert block 11 may be a male knuckle joint.

  As described above, the joints of the invert blocks 11 and 21 are only irregularities that do not use mechanical fastening members in both the longitudinal direction and the circumferential direction, and do not require fastening work such as tightening bolts during assembly. Since the work can be repeated simply by temporarily placing the invert blocks 11 and 21 and pushing them in slightly before, continuous high-speed assembly is possible, construction time can be greatly reduced, and exposed hardware is used at all. Therefore, a structure having excellent durability can be provided.

  In the example of FIGS. 2 to 4, the width of the invert blocks 11 and 21 is divided by the segment width, but it is also possible to reduce the weight by dividing the width by an integer multiple of the segment width. In either case, it is necessary to prevent the inverted blocks 11 and 21 from straddling between adjacent segment rings.

  When the invert blocks 11 and 21 straddle between the adjacent segment rings, the invert blocks 11 and 21 are caused by a misalignment caused by an assembly error, a step due to an opening, a vertical inclination that is unavoidable in design caused by joining of tapered segments, and the like. A place where the bottom surfaces of the leg portions 15 and 25 do not contact the inner surface of the tunnel 1 is generated, and when a person walks on the leg, or when a transport cart or a sliding cart travels, it is inverted due to rattling or generation of local stress. This is because the blocks 11 and 21 may be damaged such as cracks.

  FIG. 6 is a top view of two sets of invert blocks. A gap 31 of about 10 mm is provided between the joint surfaces of the invert blocks 11 and 21 in the longitudinal direction (tunnel axis direction) to absorb construction errors such as openings between the segments 2 or to be used for curved portions. The invert block installed in the taper segment is designed so that it can be installed in the same shape as the invert installed in the normal segment used for the straight portion.

  That is, if the taper amount of the taper segment 2b is small, as shown in FIG. 7, the separation amount at the time of installation of the gap 31 is finely adjusted to 31a and 31b so that both the taper segment 2b and the normal segment 2a are provided. It is also possible to use inverted blocks 11 and 21 having the same shape.

  When the center width of the taper segment 2b is the same as the width of the normal segment 2a, the shape of the invert block should be a taper shape matching the shape of the taper segment 2b or a taper shape matching the curvature radius of the curved portion. (For the end invert block, two types of the end invert block 21a and the small end invert block 21b are used in accordance with the taper), the central invert block is used for the normal segment 2a used in the straight portion. 11 and two types of end inverted blocks 21a and 21b are rotated 180 degrees around the vertical axis and alternately combined, so that the normal segment 2a used in the curved portion can be combined continuously as is, Invar with the same shape for segment 2a Block 11,21A, it is possible to continue to set up at 21b (see FIGS. 8 and 9).

  In those cases, it is needless to say that the number of types of inverted blocks can be reduced, the number of molds is reduced, and it becomes more economical. In this way, when the invert blocks 11 and 21 (11, 21a, 21b) having the same shape are installed in the segments having different shapes by fine adjustment in the gap 31, a part of the blocks straddles between the segment rings. However, since the four leg portions 15 and 25 provided on the bottom surface of the block, which is a contact portion with the inner surface of the tunnel, are slightly separated from the joint surface (see FIG. 10), the joint surface in the longitudinal direction of the block is Even when a part of the tunnel is slightly crossed between the segment rings, the inner surface of the tunnel and the contact portion of the block are not crossed.

  Further, by filling and filling the gaps 31 and 32 with a filler, it is possible to form a continuous invert without a step as in the case of hitting on the spot (the filling material injection method will be described later). On the other hand, when the filler is not injected, the gaps 31 and 32 may be made narrower and the invert block may be installed. In that case, since the range of fine adjustment by the gaps 31 and 32 becomes narrow, the shape of the inverted block must be changed according to the shape of the segment, and there is a possibility that the number of types increases as the number of types increases.

  As shown in FIG. 11, there is a method of changing only the bottom leg portions 15 and 25 by using the same mold for tunnels having slightly different inner diameters, as shown in FIG.

  Again, as shown in the front view of FIG. 10, the joints in the circumferential direction of the invert blocks 11, 21 are male / female knuckle joints 12, 22 which are circular irregularities, and there is no secondary lining. Rotation of the knuckle part even when there is a step between circumferential segment joints due to segment assembly errors, or when the inner surface of the secondary lining tunnel is not a complete arc, or when the tunnel is deformed by earth pressure, etc. As a result, the four leg portions 15 and 25 are in contact with the inner surface of the tunnel, and are not easily lifted or rattling.

  When an overload is applied to the end invert block 21 such as a person or a transport carriage, stress is transmitted from the contact surface of the knuckle portion to the central invert 11, so that the circumferential joint portion is flattened. If there is, the contact is made at the corner of the joint surface, the resistance area cannot be secured, and there is a possibility of causing damage such as cracks, but if the knuckle shape, contact at the corner can be avoided. The longitudinal joints 13, 14, 23, and 24 have a structure with only tapered irregularities that gradually decrease or increase in diameter (or width and height) in the longitudinal direction and are resistant only to shear.

  For the longitudinal drawing, the invert blocks 11 and 21 are continuously connected in the longitudinal direction, so that the invert blocks 11 and 21 installed at the front and back resist the longitudinal drawing. In particular, the structure is sufficient without providing a resistance mechanism. In addition, when the joint is transported by human power, the male / female joints 13, 14, 23, and 24 can be used as handles, and when transported using a lifting tool, a suspension band or the like is attached to the male joints 13 and 23. It is possible to hang and use it.

  FIG. 12 and FIG. 13 show a modification of the joint in the tunnel axial direction as another embodiment.

  12 shows the case where the concave and convex portions of the longitudinal joints 13, 14, 23a, 23b, 24a, and 24b are made continuous up to the upper surfaces of the respective invert blocks 11, 21, and FIG. 13 shows the longitudinal joints 13, 14, 23a. , 23b, 24a, and 24b are made continuous with the upper and lower surfaces of each of the invert blocks 11 and 21, and these have a structure that can be removed after installation.

  14 and 15 are diagrams in the case where a filler 41 such as mortar is injected into the gap between the inner surface of the tunnel 1 and the invert blocks 11 and 21. FIG. By arranging the ones with the inlet 42 in the first and last central invert blocks 11 of the injection section, one can be used for injection and the other can be used for confirmation of filling.

  In addition, before and after the injection section, a dam plate 43 is installed as necessary to prevent the filler 41 from flowing out. As the material of the weir plate 43, for example, wood, rubber, plastic, ceramics, or the like can be used.

  In the gap 31 in the longitudinal direction of the invert blocks 11 and 21, a filler outflow prevention material 44 is provided as necessary so that the filler 41 does not flow out onto the central invert block 11 which is lower than the end invert block 21. Paste. As the outflow prevention member 44, for example, rubber, plastic, foamable material, or the like can be used.

  FIG. 16 is a cross-sectional view when the through hole 51 in the tunnel axis direction is provided in the joints 23 and 24 of the end invert block 21. Thus, by providing a continuous hole in the tunnel axis direction, it is possible to pass an optical fiber or an electric wire.

  In this case, since the filler 41 may flow into the gap 31 between the joints described above, the member of the through hole 51 of the male joint 23 protrudes slightly from the joint surface, and easily contracts to that portion. It is necessary to take measures to prevent the filler 41 from flowing into the through hole 51 by covering with the covering material 52 that does not allow the filler 41 to pass therethrough. As the covering material 52, for example, rubber, plastic, foamable material, or the like can be used.

  As described in the prior art, since the sharp curve portion of the segment with invert is expensive, it is possible to construct only this portion with a normal segment without invert and arrange the invert blocks of the present invention. At that time, when the through hole is provided in the segment with invert, the through hole can be made continuous by using the invert block with the through hole 51 described above.

It is a perspective view which shows the typical form example of the invert used for the tunnel constructed | assembled by the shield construction method. It is a perspective view which shows the state built by the invert block which divided invert into 3 in the tunnel circumferential direction as one Embodiment of this invention, and divided | segmented the tunnel longitudinal direction with the segment width. 2 shows a single invert block in the embodiment of FIG. 2, wherein (a) is a plan view, (b) is a perspective view from above, (c) is a front view as seen from the tunnel axis direction, (d) Is a side view, (e) is a bottom view, and (f) is a perspective view from below. 2 shows an end inverted block alone in the embodiment of FIG. 2, wherein (a) is a plan view, (b) is a perspective view from above, (c) is a front view as seen from the tunnel axial direction, (d) Is a side view, (e) is a bottom view, and (f) is a perspective view from below. It is a perspective view of the invert part which shows the arrangement state of the invert block in the embodiment for a comparatively small diameter tunnel. It is a top view for demonstrating the clearance gap between invert blocks by arrangement | positioning of the invert block for 2 sets of tunnel axial directions. It is a top view which shows the example of arrangement | positioning which the edge part inverted block in case the taper amount of a taper segment is slight about a tunnel curve part. It is a top view which shows the example of arrangement | positioning at the time of using a large edge part invert block outside a curve, and using a small edge part invert block inside a curve about the tunnel curve part when using a taper segment and a normal segment. It is a top view which shows the example of arrangement | positioning in the case of using the same size end inverted block as FIG. 8 for a linear part. The combination of the invert blocks and the positional relationship of the legs provided on the lower surface of the invert block are illustrated, (a) is a plan view, (b) is a front view seen from the tunnel axis direction, and (c) is a side view. (D) is a bottom view. It shows an embodiment when only the bottom leg is changed using the same formwork for a tunnel with a slightly different inner diameter, (a) is a front view when the diameter is small, (b) is a large diameter It is a front view in the case. It is a perspective view of the invert part which shows the modification about the coupling of a tunnel axial direction as other embodiment. It is a perspective view of the invert part which shows the other modification of the coupling of a tunnel axial direction. It is a top view which shows embodiment at the time of inject | pouring a filler into the clearance gap between a tunnel inner surface and an invert block as other embodiment. FIG. 15 is an enlarged vertical sectional view corresponding to FIG. 14. It is sectional drawing at the time of providing the through-hole of a tunnel axial direction in the joint part of an end invert block as other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Tunnel, 2 ... Segment, 2a ... Normal segment, 2b ... Tapered segment, 3 ... Invert, 4 ... Groove,
DESCRIPTION OF SYMBOLS 11 ... Invert block of center part, 12 ... Male knuckle joint, 13 ... Male joint, 14 ... Female joint, 15 ... Leg part, 19 ... Chamfering,
21 ... End inverted block, 21a ... End inverted block (large), 21b ... End inverted block (small), 22 ... Female knuckle joint, 23 ... Male joint, 23a ... Male joint (large), 23b ... Male joint (Small), 24 ... female joint, 24a ... female joint (large), 24b ... female joint (small), 25 ... leg, 29 ... chamfering,
31 ... gap, 31a ... gap (large), 31b ... gap (small),
DESCRIPTION OF SYMBOLS 41 ... Filler, 42 ... Injection port, 43 ... Swash plate, 44 ... Outflow prevention material, 51 ... Through-hole, 52 ... Covering material

Claims (9)

The invert provided below the inner surface of the tunnel cross section composed of a large number of segments is formed by connecting a plurality of invert blocks each having a shape divided into a plurality in the tunnel circumferential direction and the tunnel axial direction, and the invert block is formed on the lower surface. Between the invert blocks adjacent to each other in the tunnel circumferential direction, which has a plurality of legs in contact with the inner surface of the segment, it is allowed to rotate in the vertical plane at the connecting portion, and between the invert blocks adjacent in the tunnel axial direction. In between, a gap is provided between the male and female joints that are fitted together to allow rotation in the horizontal plane in the fitted state, and the inner surface of the segment and the lower surface of the invert block are in direct contact with each other. without, inverter, wherein the plurality of legs is in contact with the inner surface of the segment becomes a fulcrum Door.   2. The invert according to claim 1, wherein the invert blocks adjacent to each other in the circumferential direction of the tunnel are connected via a knuckle joint that is in contact with curved surfaces. The invert according to claim 1 or 2, wherein a filler is filled in an inner surface of a segment and a lower surface of the invert block and / or a gap between the invert blocks.   The invert block is divided into three invert blocks of a center invert block and end invert blocks on both sides thereof in the tunnel circumferential direction, and the center invert sandwiched between the end invert blocks. 4. The invert according to claim 1, wherein a part or the whole of the upper surface of the block forms a bottom surface of a groove extending in the tunnel axis direction of the invert. The invert provided below the inner surface of the tunnel cross section composed of a number of segments has a shape divided into a plurality of each in the tunnel circumferential direction and the tunnel axial direction, and a plurality of the inverts in contact with the inner surface of the segment when the tunnel cross section is formed on the lower surface There are legs, and at least one side in the circumferential direction of the tunnel is formed with a joint that allows rotation in the vertical plane at the connection with the adjacent invert block. between the invert block adjacent to each other in, had fitted case made to have a clearance from each other, male fittings and / or concave female coupling convex shape to permit rotation in the horizontal plane is formed a invert block comprising Te and without contacting the lower surface of the inner and invert block of the segment directly when you configure the tunnel cross section, Invert block, wherein a serial plurality of legs is in contact with the inner surface of the segment becomes a fulcrum.   6. The invert block according to claim 5, wherein a concave curved surface or a convex curved surface constituting a knuckle joint that is in contact with adjacent invert blocks by curved surfaces is formed on at least one side in the tunnel circumferential direction.   Between the male joint and / or the female joint formed on both sides in the tunnel axial direction, a through-hole penetrating the inside of the male joint and continuing in the tunnel axial direction is formed. Item 7. The inverted block according to item 5 or 6.   The invert block according to claim 5, 6 or 7 is sequentially installed while being connected in the tunnel circumferential direction and the tunnel axial direction below the inner surface of the tunnel cross section composed of a number of segments. Building method. The invert construction method according to claim 8, wherein a filler is filled in an inner surface of a segment and a lower surface of the invert block and / or a gap between the invert blocks.

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