JP2019157620A - Manufacturing method for composite segment - Google Patents

Abstract

To provide a manufacturing method for a composite segment with high watertight and cut-off performance being applicable to shield tunnels which are expected to experience severe loads, such as those built in very deep sites or designed with variant cross sections.SOLUTION: A composite segment 1 for tunnels comprises concrete 60, steel shells 6 and cut-off material. The steel shell is arranged at least at part of the composite segment's outer peripheral surface consisting of main girder surfaces 3 being the end faces in the direction of the tunnel's axis and joint faces 4 being the end faces in the tunnel's circumferential direction. The manufacturing method for the composite segment comprises: a step of placing at least one inner surface cut-off material on the inner side of the steel shell; a step of installing the steel shell on a casting mold; a step of arranging reinforcement bars inside the steel shell; a step of casting concrete inside the steel shell; and, after demolding, a step of fitting an outer peripheral cut-off material 82 in a complete round on the composite segment's main girder faces and the joint faces.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a segment used in tunnel construction, particularly tunnel construction by a shield method. More specifically, the present invention relates to a synthetic segment filled with concrete inside a steel shell.

  In addition to mountain tunnels and submarine tunnels, underground roads, railway tunnels, sewer tunnels, underground river tunnels, etc. in urban areas that are difficult to be newly installed in shallow underground are excavated with shield machines, and there are segments in the tunnels that have been excavated. A method is used in which tunnels are constructed by connecting the fan-shaped members called vertically and horizontally.

  Even when the tunnel interior is used as a road or railway, or when the tunnel interior is used as a rainwater channel or sewer, there are differences in the water pressure and earth pressure acting on the inner and outer surfaces with the tunnel wall as the boundary. For this reason, the waterproof structure of the tunnel wall is an important issue considering the cost of water leakage countermeasures after completion and the impact on the environment.

  In particular, in a shield tunnel in which a large number of segments are connected vertically and horizontally to form a tunnel wall, the water stop structure at the joint portion between the segments (the joint of the segments) is regarded as most important.

The waterproof structure of the shield tunnel is
(A) Waterproofing by backfilling injection material located on the back side of the segment, that is, the natural ground side,
(B) Waterproofing applied to the joint surface of the segment, and (c) Waterproofing by secondary lining applied to the inside of the tunnel,
Etc.

The waterproofing by the backfilling material is carried out mainly for equalizing the water pressure acting on the tunnel structure by injecting the appropriate backfilling material, such as the disturbance of the natural ground layer during shield excavation.
On the other hand, water stoppage by secondary lining has been most commonly carried out until recently, but it has occurred for a long time due to the occurrence of seams in secondary lining and cracks caused by drying shrinkage during lining. Therefore, it is difficult to expect a highly reliable water-stopping effect.

  As a recent trend, secondary lining is often omitted due to improved segment performance. Therefore, the waterproof structure of the tunnel structure is a measure for waterproofing at the joints of the segments constituting the tunnel wall. It can be said that it depends on whether it can be implemented reliably.

  In the synthetic segment manufacturing method described in Patent Document 1, in order to densify the peripheral edge of concrete, instead of so-called boat driving, in which the steel shell is placed in a convex shape when placing the concrete, Adopting the so-called `` striking '' that is placed in a convex shape, a water-stopping member is placed around the concrete filling hole provided in the center part of the natural ground side of the segment to improve the water-stopping property at the interface between the steel shell and concrete Thus, a method for preventing water from entering between them is disclosed.

  Furthermore, in the technique shown in Patent Document 2, in a synthetic segment in which an outer shell body having a frame member formed in a hollow frame shape and a concrete filling member formed in the outer shell body are integrated. A water stop member made of an elastic material fixed to the inner peripheral surface portion of the frame member, and the water stop member between the inner side surface of the frame member and the concrete to stop the outer shell body and the concrete. In the meantime, there is disclosed a technique that can exhibit a high yield strength against a strong shearing force acting in the arc radial direction and can manufacture a structure capable of stopping water without using a skin plate as in the related art at a low cost.

JP 2014-88658 A JP 2014-88720 A

However, any of the above conventional techniques
・ Water stoppage performance is not sufficient.
・ The elastic reaction force of the water-stopping material that satisfies the relational conditions between water pressure and concrete strength tends to be insufficient.
・ The steel shell that constitutes the outer shell is deformed out of the plane due to the elastic reaction force of the water-stopping material and peels off from the concrete. As a result, the concrete escapes from the steel shell, and the water stoppage performance and the mechanical performance of the segment cannot be exhibited as calculated.
・ If the elastic reaction force of the water-stopping material is insufficient, it will affect the binding force of the concrete by the steel shell, and the concrete will be easily damaged due to the sliding of the concrete.
-Therefore, the application tends to be limited to shallow tunnels with low groundwater pressure.
・ Applicable to small, uniform, shallow tunnels, small cross-section tunnels, or circular tunnels with small load load on the segment, and non-uniform loads are applied by large-scale tunnels with large load loads and tunnel cross-sections. Difficult to apply to non-circular tunnels,
And so on.

  The present invention has a high water-stopping performance on the joint surface between the steel shell of the composite segment used for shield tunnel construction and the like and the concrete, and increases the binding force of the concrete by the steel shell, so that the steel shell and the concrete are integrated. The goal is to provide a composite segment that can be applied to deep or non-circular cross-section tunnels that are subject to high loads and non-uniform loads. And

In order to improve the segment strength and water stop performance, the present inventors have conducted various studies,
・ Improve the water stop performance of the dissimilar material interface between steel shell and concrete in the composite segment,
・ Improves the water stop performance at the joint surface between adjacent synthetic segments simultaneously,
・ Achieved elastic reaction force of water-stopping material that satisfies the relationship between water pressure and concrete strength,
-Increase the binding force of the steel shell against the concrete so that the concrete does not escape from the steel shell due to the action of abdominal pressure.
As a result, we have reached the knowledge that excellent segment strength and water stopping performance can be demonstrated.

The synthetic segment according to the present invention in which the above knowledge is realized is as follows.
・ Applicable to deep tunnels with high groundwater pressure
・ It can be applied to deep tunnels with large load and cross-sectional force, large cross-section tunnels, or non-circular cross-section tunnels.
・ High water-stop performance can be expected for a long period of time, realizing a longer tunnel life and lower maintenance costs.
・ By increasing the binding force between the steel shell and concrete, it prevents cracks in the concrete during earthquakes or internal water pressure acting on tunnels such as underground rivers.
Such effects can be expected.

  The present invention has been completed based on the above findings, and the gist thereof is as follows.

  (1) A method for manufacturing a composite segment for a tunnel having concrete, a steel shell, and a waterstop material, wherein the steel shell includes a main girder surface that is an end surface on the axial direction side of the tunnel of the composite segment, The manufacturing method is arranged on at least a part of an outer peripheral surface constituted by a joint surface that is an end surface on a circumferential direction side, and the manufacturing method includes a step of disposing at least one inner surface water blocking material on the inner surface side of the steel shell with respect to the concrete; A step of installing the steel shell in the casting mold, a step of installing a reinforcing bar inside the steel shell, a step of placing concrete inside the steel shell, and after demolding, Disposing an outer peripheral water stop material over the entire circumference of the main girder surface and the joint surface.

  (2) An inner surface water stop groove is provided on the inner surface of the steel shell, and the step of arranging the at least one inner surface water stop material includes placing the at least one inner surface water stop material in the inner surface water stop groove. The manufacturing method of the synthetic segment as described in said (1) including arrange | positioning.

  (3) The placement mold is configured to support the composite segment so that the four corners of the composite segment are aligned horizontally and to contact a ground-side surface of the composite segment. The manufacturing method of the synthetic segment as described in 1) or (2).

  (4) The placement mold form is configured to support the composite segment so that four corners of the composite segment are horizontally aligned and to contact an inner surface of the composite segment, (1) The manufacturing method of the synthetic segment as described in (2).

  (5) The placement mold form supports the composite segment diagonally so that one joint surface of the composite segment is higher than the other joint surface, and is provided on the inner space side of the composite segment. The manufacturing method of the synthetic segment as described in said (1) or (2) comprised so that a surface or the surface of a natural ground side may be contacted.

  (6) The placement mold is configured to support a plurality of composite segments arranged in a ring shape and to contact an outer peripheral surface of the plurality of composite segments on a natural ground side. The step of placing concrete on the mold form comprises rotating the cast formwork around the center axis of the ring, and from an inner position of the cast formwork from a predetermined position inside the cast formwork. The method for producing a synthetic segment according to (1) or (2), comprising discharging the ready-mixed concrete toward a predetermined position on the surface.

  (7) The steel shell is disposed only on a part of the outer peripheral surface composed of the main girder surface and the joint surface, and the manufacturing method includes the main girder surface and the joint in the placing mold The synthetic segment manufacturing method according to any one of (3) to (5), further comprising a step of installing an auxiliary formwork at a position where the steel shell is not disposed in the outer peripheral surface constituted by a surface. .

  (8) Any of (1) and (7), wherein at least one outer peripheral water stop groove is provided on the main girder surface and joint surface of the synthetic segment, and the outer peripheral water stop material is disposed in the outer peripheral water stop groove. A method for producing the synthetic segment according to claim 1.

(9) In the above (1) to (8), the crack strength of the concrete, the elastic reaction force of the inner surface water blocking material, and the water pressure acting on the tunnel satisfy the following relational expressions: A synthetic segment according to any one.
(Concrete crack strength)> (Internal waterstop elastic reaction force)> (Water pressure acting on the tunnel)

  (10) The synthetic segment according to any one of (1) to (9), wherein the end portion of the inner surface water-stopping material and the outer peripheral water-stopping material are in contact with each other.

  (11) Steel shells are arranged on both main girder surfaces of the synthetic segment, the connecting material for connecting the steel shells, and the reinforcing bars are arranged in contact with the connecting material. The synthetic segment according to any one of 10).

  (12) The composite segment according to (11), wherein the connecting material is provided in contact with both the natural mountain side and the inner air side of the reinforcing bar.

  (13) The synthetic segment according to any one of (1) to (12), wherein at least a part of the waterstop material is a water-swellable waterstop material.

  (14) The synthetic segment according to any one of (1) to (13), wherein the outer periphery water-stopping material is a water-swellable water-stopping material, and the inner surface water-stopping material is a non-water-swelling water-stopping material.

  (15) One or more of the main girder surface and joint surface of the synthetic segment is the steel shell including a corrugated surface having an uneven portion, and the concave portion of the corrugated surface is an outer circumferential water stop. The synthetic segment according to any one of (1) to (14), which is a groove or a water-stop groove on the inner surface of the steel shell.

  The present invention is excellent in watertight waterproof performance and binding force between the steel shell and concrete, and the water stop performance at the joint between the segments continues for a long period of time. In addition to improving the integrity of the steel shell and concrete with respect to the segment, it can also improve the water stoppage between adjacent composite segments, and can be applied to shield tunnels with large depths, large cross sections, and non-circular cross sections. Provide segments.

It is a perspective view which shows the tunnel constructed | assembled by a segment. It is a perspective view at the time of making the main girder surface and the whole joint surface of the synthetic segment of the present invention into a steel shell. It is the perspective view at the time of making the four corners of the synthetic segment of this invention into a steel shell, and the enlarged view of a steel shell. It is a conceptual diagram at the time of making the main girder surface of the synthetic segment of this invention into a steel shell. It is a plane conceptual diagram which shows the connection structure of the inner surface water stop material and outer periphery water stop material in the synthetic | combination segment of this invention. It is sectional drawing which shows the connection structure of the connection material which connects the main girder surfaces of this invention, and a reinforcing bar. It is a schematic diagram which shows the state which concrete pouring pressure acts on a non-swelling and swelling water-stopping material. It is a graph which shows the relationship between concrete crack strength, concrete placement pressure, and design water pressure. It is a conceptual diagram at the time of changing the swelling property etc. of the water stop material in a main girder surface. It is a schematic diagram of the form which gave the corrugated shape which can be fitted to joined surfaces, such as a main girder steel plate and a joint steel plate. It is the A section enlarged view of FIG. It is a schematic diagram which shows a synthetic segment provided with a fixing material and a slip stopper. (A)-(e) is a schematic diagram which shows the manufacturing method of a synthetic segment.

Hereinafter, the present invention will be specifically described.
As shown in FIG. 1, the composite segment of the present invention is configured such that a plurality of composite segments 1 are connected in the axial direction X of the tunnel cross section and the circumferential direction Y of the tunnel cross section, whereby the tunnel 7 is constructed. .

  The tunnel 7 is provided in an excavation hole formed by excavating a natural ground by a shield method. In the example shown in FIG. 1, the segment ring 70 having a circular cross section is formed by connecting 11 segments in the circumferential direction (Y direction) of the tunnel cross section. Or an elliptical cross-sectional shape. The segment ring 70 blocks the ground outside the normal line of the tunnel 7 (Z1 direction), thereby forming a tunnel inner space inside the normal line of the tunnel 7 (Z2 direction).

  As shown in FIG. 2, the composite segment connects a pair of main girder surfaces 3 and 3 that define the outer shape of the tunnel cross section and the ends of the pair of main girder surfaces to each other in the circumferential direction of the tunnel cross section. And a pair of joint surfaces 4 and 4 that define a joint surface with a composite segment adjacent to each other.

In the present invention, the four sides defining the outer shape of the composite segment are referred to as a main girder surface or a joint surface regardless of whether they are formed of a steel material or a concrete molding surface.
In the form shown in FIG. 2, the main girder surface 3 and the joint surface 4 of this composite segment are formed by main girder steel plates 31 and 32 and joint steel plates 41 and 42, respectively, and are defined by the main girder steel plates and the joint steel plates. An outer peripheral water stop groove 100 is provided on the outer peripheral surface of the synthetic segment over two steps in the height direction (Z direction) of the synthetic segment, and an outer peripheral water stop material 82 is installed in the water stop groove. . By installing the water stop material in the water stop groove, the water stop material is restrained and the water stop effect is enhanced. Similarly, the inner water stop material 81 can also be provided with an inner water stop groove to improve the water stop effect.
In the case of manufacturing a composite segment of this form, the steel shell 6 formed of a main girder steel plate and a joint steel plate is placed on a kamaboko-shaped form table that defines the inner surface side of the tunnel, and the natural ground side is defined. The frame is covered with a mold, and the concrete 60 is filled in the frame 6a to form a synthetic segment made of a rectangular steel shell and concrete. Note that the steel shell 6 may be provided on at least one of the main girder surfaces 3 and 3 and the joint surfaces 4 and 4, and in that case, concrete is formed by using a formwork that restrains the main girder surface or the joint surface. 60 is filled. In addition, the inner surface water blocking material 81 may be installed in the steel shell 6 in advance before placing the concrete, and the outer circumferential water blocking material 82 may be installed after the mold is removed.

<Concrete variations>
Moreover, as a kind of the concrete 60, non-shrinkable concrete or concrete to which an appropriate expansion material is added may be selected in addition to normal concrete to improve the concrete filling rate.

<Variation of the shape of the steel shell>
In the embodiment shown in FIG. 2, the main girder surface and the joint surface that define the rectangular outer surface of the segment are all formed of a steel plate. However, as another embodiment of the present invention, as shown in FIG. Only the corners (four corners) of the composite segment where the main girder surface and the joint surface are in contact may be formed by the corner steel plate 5. In this example, the inner surface water-stopping material 81 and the outer periphery water-stopping material 82 are arranged in a single center in the height direction (Z direction) of the composite segment. Are installed in the inner surface water stop groove 101 and the outer periphery water stop groove 100 provided at the same position in the height direction (Z direction) of the composite segment on both surfaces of the corner steel plate 5.

  By making only the corner part a steel shell, it is possible to reduce the weight of the synthetic segment, and when the segment is constructed, it tends to come into contact with or collide with the existing segment part and cause defects such as cracks and chips. The strength of the corner portion of the segment can be improved. Furthermore, in the water stop performance in the joint surface of adjacent synthetic segments, the water stop performance of the corner part of the segment used as the weakest point can be improved appropriately.

  Further, as shown in FIG. 4A, only the main girder surface 3 may be formed of main girder steel plates 31 and 32. As shown in the cross section AA in FIG. 4B, in this example, the outer peripheral water-stopping material 82 and the inner surface water-stopping material 81 have a height of the synthetic segment 1 in two steps in the thickness direction of the synthetic segment 1. It is arranged in pairs in the water stop grooves 100, 101 provided in the same position in the vertical direction (Z direction) and facing the inner and outer surfaces of the steel shell, and improves the water stoppage of the boundary surface between the steel shell and the concrete. At the same time, the water stoppage between adjacent segments is also improved. On the other hand, the joint surface formed of concrete without a steel shell has the same Z direction as the outer peripheral water blocking material 82 and the inner surface water blocking material 81 of the main girder surface 3 as shown in FIG. In the water stop groove 100 provided on the outer periphery, only the outer peripheral water stop material 82 is arranged in two stages in the thickness direction of the synthetic segment. FIG.4 (d) is the cross-sectional enlarged view of the water stop groove | channel provided in the steel shell of the main girder surface, and the water stop material arrange | positioned in this groove | channel.

  On the other hand, it is also possible to employ a steel shell only on the joint surface of the synthetic segment.

  In either case, an inner surface water-stopping material is installed on the inner surface side of the steel shell in contact with the concrete, and the outer peripheral surface of the segment is continuously formed across the portion made of steel shell and the surface made of concrete. By installing the outer peripheral water stop material in the outer peripheral water stop groove 100, it is possible to achieve a high water stop / waterproof structure at the joint surface between the steel shell inner surface and the concrete and between the adjacent synthetic segments. . The water pressure acting from the ground outside the tunnel acts on the segment ring and tries to form a water channel between the steel shell inner surface and the joint surface of the concrete. By providing a water stop / waterproof structure that resists this, the water channel can be blocked, while water pressure similarly acts on the joint surface between adjacent synthetic segments. For this reason, the outer and inner surfaces of the composite segment can be synergistically water-proofed and waterproofed by placing the inner and outer water-stopping materials in pairs in the height direction (Z direction) of the segments. Excellent segment strength and water stop performance.

  As conceptually shown in a plan view in FIG. 5 (a), when the main girder surface and the entire joint surface are formed of the main girder steel plates 31, 32 and the joint steel plates 41, 42, Similarly, the inner surface water-stopping material 81 can also be formed continuously in an annular shape forming a quadrilateral, but in a form in which only the main girder surface or the joint surface, or only the corner portion is formed of a steel shell, these In the end part of the steel shell, the end part of the inner surface water-stopping material 81 extends toward the outer edge of the segment, and is configured to come into contact with the outer peripheral water-stopping material 82 on the outer peripheral surface of the segment. It is possible to improve the water stopping performance at the contact surface.

That is, the inner surface water-stopping material 81 includes main girder steel plates 31 and 32, joint steel plates 41 and 42, except for the configuration in which the entire outer periphery of the segment is formed of a steel shell using main girder steel plates and joint steel plates. Alternatively, it is installed only on the inner surface of the steel shell formed by the corner steel plate 5, and the end portion of each steel plate extending toward the outer surface of the segment main body is in contact with the rectangular outer circumferential water stop material 82. Configured as follows. This state is shown in FIGS.
Specifically, as shown in the enlarged view of FIG. 3, the end portion of the inner surface water blocking material 81 is extended so as to protrude from the main girder surface and the joint surface formed by the concrete filled in the middle, The protruding portion may be folded inside the outer peripheral water stop material 82 that is attached later so that the end portion of the inner surface water stop material 81 is in contact with the outer peripheral water stop material 82.

  The inner surface water-stopping material 81 ensures the water-stopping performance of the joint surface between the inner surface of the main girder steel plate, joint steel plate, or corner steel plate and the concrete 60, and changes in load load due to aging, earthquakes, etc. Even if it exists, the joining state of steel shell and concrete is maintained.

  In the form of using the main girder steel plate and the joint steel plate, the entire outer periphery of the segment is made of steel shell, the form of only the main girder surface made of steel plate, the form of only the joint surface made of steel plate, etc. In order to improve the strength of the part and increase the adhesion between the steel shell and the concrete, in addition to the normal reinforcing steel bar structure consisting of reinforcing bars extending in the main girder steel plate direction and reinforcing steel bars extending in the joint steel plate direction, the connecting material Can be installed to improve the strength of the segment itself and the adhesion strength between the steel shell and the concrete. Furthermore, in the vicinity of the surface layer forming the natural ground surface and inner surface of the composite segment, a lattice-like member made of a reinforcing bar or the like can be embedded for the purpose of preventing cracks on the concrete surface.

<Application of connecting material and variation of reinforcing bar structure>
In the form shown in FIG. 6, the main girder steel plates 31 and 32 are connected by an axial connecting member 61 extending in the tunnel axis direction. 6A to 6D, the left side is a cross-sectional view in a direction perpendicular to the main girder surface, and the right side is a cross-sectional view in a direction parallel to the main girder surface.
In this embodiment, in FIG. 6 (a), the reinforcing bar 64 orthogonal to these connecting members is arranged on the tunnel space side (Z2 direction side) of the connecting member 61, and water pressure such as rainwater filling the tunnel is obtained. The resistance against the expansion force (concrete pull-out force) exerted on the segment is increased.

  On the other hand, in the form shown in FIG. 6B, the reinforcing bars 64 are arranged on the ground mountain side (Z1 direction side) of the similarly arranged connecting member 61, and against the pressure (abdominal pressure) from the ground mountain side toward the space in the tunnel. Increased durability.

  Furthermore, in another embodiment of the present invention, as shown in FIG. 6 (c), for example, the connecting member 61 is alternately arranged on both the tunnel ground side and the tunnel space side with respect to the similarly disposed reinforcing bars 64, for example. Arranged to achieve high durability against both the pressure from the natural ground and the internal pressure from the fluid that fills the space in the tunnel.

  Furthermore, in another form, as shown in FIG.6 (d) and its partial enlarged view, the opening 63 is formed in a connection material, and the rebar 64 is penetrated through this hole, so that the concrete removal force and the abdominal pressure can be reduced. Can resist both. Furthermore, even in a synthetic segment with a small design thickness, a dense reinforcing bar structure can be realized while suppressing adverse effects on concrete placement, and the strength of the entire segment can be improved. In addition, it may replace with the opening 63 and may provide the notch for making positioning and a fitting of a reinforcing bar easy.

  Although the connecting material described above extends in the tunnel axis direction and connects the main girder steel plates, a similar connecting material can be arranged to connect a pair of joint steel plates. That is, connecting a pair of joint steel plates in the circumferential direction, placing a connecting material having a curve similar to that of the main girder steel plate, and connecting the reinforcing bars perpendicular to this to the tunnel space side of each circumferential connecting material, Either a natural mountain side, or both a tunnel space side and a natural mountain side, or a form in which an opening is provided in a connecting material and penetrated or a notch is provided to be combined with this is adopted. Can do.

With regard to the positional relationship between the various connecting materials and the reinforcing bars, if the connecting materials are arranged outside the reinforcing bars, that is, on the natural ground side (Z1 direction side), a high resistance can be exerted against the fluid pressure that fills the space in the tunnel. If it is arranged on the side of the tunnel inside the tunnel space (Z2 direction side), a high proof stress can be exerted against the abdominal pressure from the natural mountain side. In addition, for example, if they are alternately arranged, a high resistance against pressure from both the inner and outer surfaces of the tunnel can be expected. The effect is that the concrete is not constrained by the skin plate in the case of the so-called 4-sided steel shell segment in which the main girder steel plate and joint steel plate form a steel shell without providing a skin plate on the natural ground side of the tunnel. From, it becomes particularly important.
Furthermore, if the structure is made to penetrate the opening provided in the connecting material or to be engaged with the notch, it becomes easy to position and temporarily fix the reinforcing bar, and it becomes easy to design the reinforcing bar structure and thus the synthetic segment to be thinner. There are also advantages.

<Waterproof structure on the inner surface of steel shell>
In the present invention, as described above, an inner surface water stop groove is formed on the inner surface of the steel shell forming a part of the formwork, that is, on the contact surface side with the concrete, if necessary. Is installed to prevent water leakage from the gap between the joint surfaces of the steel shell 6 and the concrete 60. By installing the water stop material in the water stop groove, the water stop material is restrained and the water stop effect is enhanced.

As the water stop material on the inner surface side, a water swellable water stop material with an appropriate swelling speed can be adopted in addition to a normal elastic rubber one, but in the waterproof design, the crack strength of concrete, Taking into account the elastic reaction force of the water stop material in the inner groove and the design water pressure of the tunnel constructed by the composite segment,
(Concrete crack strength)> (Internal waterstop elastic reaction force)> (Water pressure acting on the tunnel)
Therefore, it is necessary to appropriately set the material characteristics of the concrete, the material characteristics of the water-stopping material, dimensional specifications, and so on. If the elastic reaction force of the inner waterstop is greater than the concrete crack strength, the concrete in contact with the inner waterstop will be overloaded locally, causing the bearing to break and causing cracks in the concrete. A water channel is formed, causing water leakage. When the water pressure acting on the tunnel is larger than the elastic reaction force of the inner surface water-stopping material, the water-stopping effect of the water-stopping material is insufficient, causing water leakage.

<Setting of elastic reaction force of inner surface water stop material>
Regarding the elastic reaction force of the water-stopping material installed in the inner groove of the inner peripheral surface of the steel shell, consider the strength of the concrete that composes the composite segment, the design water pressure acting on the tunnel, and also consider the manufacturing process of the composite segment And decide.
That is, in the synthetic segment manufacturing process, when a water-swellable material is used as the water stop material, the elastic reaction force of the inner surface water stop material is added to the elastic reaction force of the material as shown in FIG. When the swelling pressure due to moisture absorption is applied, the water-stopping material maintains its shape against the concrete pouring pressure, but this swelling pressure increases with time as shown in FIG. Moreover, the hardening rate of concrete depends on the blending method of concrete and the curing method and curing time after placing the concrete. Taking these into consideration, considering the increase in swelling pressure due to moisture in the concrete, the material properties and size of the water-stopping material (elastic reaction force + swelling pressure) are kept below the strength of the hardened concrete ( (Cross sectional area and shape).
For example, when the concrete design standard strength is 42 MPa and the water pressure acting on the tunnel is 0.5 MPa, the crack strength of the concrete is 15 MPa when evaluated by the bearing strength. Therefore, the inner surface waterstop elastic reaction force needs to be set in a range of 0.5 MPa <elastic reaction force <15 MPa. The material properties of the water-stopping material are determined by setting the material and shape based on the compression rate and compression speed when the material is compressed, and the expansion rate. It is desirable to confirm and set characteristics that satisfy the process. As an example, in the manufacturing process of the synthetic segment, the expansion rate of the water-stopping material depends on the rate at which the initial strength of the concrete develops for 1-2 days from the placement of the concrete until the initial strength of the concrete is expressed. By adjusting, the generation of cracks during the manufacturing process can be suppressed. In order to increase the water tightness, if you want to apply an elastic reaction force strongly, set the expansion rate of the waterstop material so that it is longer than the period when the initial strength of the concrete is developed and smaller than the crack strength of the concrete. good. Moreover, in order to avoid an excessive elastic reaction force to concrete, it is good to make a compressibility into about 40% or less. The height of the water stop material is preferably set to about 5 mm to 50 mm, and the thickness of the water stop material is preferably set to about 5 mm to 20 mm.

<Waterproof structure of segment joint surface>
Similar to the inner water stop structure, an outer peripheral water stop groove is continuously formed on the outer peripheral surface of the steel plate and concrete main girder surface and joint surface, and an outer peripheral water stop material is installed in the groove. The water stop structure is formed at the joint surface with the adjacent segment. Thus, by providing an outer periphery water stop groove continuously, the flow path of water is interrupted | blocked and water stop performance improves.
In the example shown in FIG. 2 and FIG. 4, a seal structure is formed when an outer peripheral water-stopping material 82 is provided in two upper and lower stages with a distance in the segment height direction (Z direction) and joined to an adjacent segment. Like to do.

  The connection parts of the main girder steel plates 31 and 32 and the joint steel plates 41 and 42 are also joined in a watertight manner by welding or the like, over the entire circumference of the joint surface between the steel shell and the concrete that is likely to be cracked or peeled off. The inner surface water-stopping material is installed, and further, the outer periphery water-stopping material installed on the outer peripheral surface (joint surface) of the synthetic segment, the seal structure on the joint surface between the segments is installed, etc. A high water-stop and waterproof structure can be constructed between the inner and outer surfaces of the completed tunnel.

<Variation of inner water stop material>
When the synthetic segment according to the present invention is manufactured, particularly when concrete is filled, the joint surface at both ends in the circumferential direction of the segment is placed on the floor surface, rather than placing the center of the outer surface of the segment on the floor surface. It is preferable to fill the concrete with a so-called “striking”. In the case of face-down hitting, since it is placed on a kamaboko-shaped mold base that defines the inner surface side of the tunnel, the finishing process of the concrete surface on the inner surface side of the tunnel is not required, and the manufacturing cost can be reduced. In addition, by adopting the downturning, the concrete near the joint surface portion constituting the joint surface with the adjacent segment becomes dense due to the high filling pressure, which contributes to the improvement of the strength of the completed tunnel.

  As described above, when placing concrete, an inner surface water blocking material is placed in the groove on the inner surface of the steel shell and filled with concrete. In contrast to the start of concrete filling, the concrete begins to receive concrete filling pressure in a short time and receives high filling pressure as the filling progresses. A relatively small filling pressure is applied.

In order to deal with the above-described imbalance of the filling pressure, the properties of the inner surface water stop material arranged along the main girder surface can be changed depending on the part.
For example, when a water-swellable material is used for the inner surface water stop material installed on the main girder surface, a water stop material with a relatively low swelling speed is used as the water stop material near the joint surface on both sides, In consideration of the slow start of contact with moisture contained in the concrete, the degree of swelling of the water-stopping material installed on the inner surface of the main girder surface by making the water-stopping material with a relatively fast swelling speed, It is possible to make the waterproof structure between the steel shell and the concrete uniform over the entire inner surface of the main girder surface by making it substantially uniform regardless of the part. Based on the same concept, use a material with relatively small swelling or swelling pressure as the water-stopping material near the joint surfaces on both sides, and a material with relatively large swelling or swelling pressure at the center of the segment. You can also.

In the above-described embodiment, a material having a difference in the swelling speed of the water-stopping material is adopted as a different water-stopping material. In addition, a portion close to the joint surface is a non-water-swellable material, and the remaining segment center By making the part a water-swellable material, the waterproof performance between the steel shell and the concrete can be enhanced as a whole segment depending on the presence or absence of swelling.
A conceptual diagram of these embodiments is shown in FIG. In the illustrated example, as a guideline, the magnitude of the swelling speed and the presence or absence of swelling are changed at the center 1/3 of the main girder surface and 1/3 of each end.
The water pressure of the tunnel acts directly on the joint surface with the adjacent segment. Furthermore, since external forces act on the tunnel, there is a possibility that the joint surface of adjacent segments may be misaligned or open. Therefore, in order to cope with water pressure and gaps, the peripheral waterstop material is a water-swelling type waterstop. By providing the material, the manufacturing cost can be reduced by adopting a non-water-swelling water-stopping material on the inner surface side where the gap with the concrete is not larger than that of the outer peripheral surface.

<About the shape of the composite segment connection surface>
For the joint surfaces of the composite segments, i.e., the connection surfaces of the main girder surfaces and the joint surfaces, by adopting a shape / structure that can be fitted to the connection surfaces themselves, rather than just a flat plate shape, It is possible to enhance the watertight connectivity between the segments with a stronger coupling surface. At the same time, between the steel shell and the concrete, the concrete is densely filled into the concave and convex shapes of the fitting, so that the water-stopping and integrity are enhanced at the same time, and the performance of the synthetic segment is enhanced.
For example, main girder steel plates 31 and 32 having a corrugated cross section as shown in FIG. This main girder steel plate has a shape that fits between the inner and outer surfaces of the steel plate, and a pair of main girder steel plates that are fitted together with one kind of cross-sectional shape by inverting the inner and outer surfaces. Since the girder surface can be formed and the concave and convex space can be formed in the fitting portion, it is rational and the manufacturing cost can be reduced.

  In this example, corrugated fitting irregularities are respectively provided on the ground side and the tunnel space side of the composite segment, and when the synthetic segments are connected to each other, two pairs of outer peripheral water stoppages on each fitting irregularity A material 82 is installed.

  The outer peripheral water blocking material 82 may be a simple elastic body or a swellable elastic body. In any case, as shown in the enlarged view of FIG. The shape and size must be determined so that a space capable of + (swelling deformation) can be formed.

  Similarly, on the inner surface side of the steel shell that is in contact with the concrete, the recesses in each of the fitting irregularities can be used as the water stop groove as they are, so if the inner surface water stop material is arranged in the recess, the water stop material is constrained and watertight. Increases nature. Moreover, since the convex part functions as a slip stopper that resists the concrete coming out in the direction of the segment height (Z), the load resistance performance of the composite segment is dramatically improved.

<Waterproof outer surface opening hole>
In addition to the above-described fitting uneven surface, the main girder surface and the joint surface constituting the four sides of the composite segment may be provided with a bolting structure for connecting to the adjacent segments, and other fitting structures, respectively. is there.
In order to incorporate these structures, an opening hole is provided in the surface of the main girder surface or joint surface of the segment.
In the opening hole, the connection structure with the adjacent segment itself is arranged, and if moisture enters into this part and rusts, the segment connection strength is lost, and the tunnel itself has a very serious problem in terms of strength. Therefore, an inner surface water-stopping material or an outer peripheral water-stopping material may be installed in an annular shape around the opening hole to prevent moisture from entering the opening hole and prevent rusting of the joint structure.

In the present invention, as shown in FIG. 2, a skin plate 9 made of a thin steel plate can be arranged on the ground side of the synthetic segment to enhance the outer surface strength and water stopping performance of the synthetic segment.
Furthermore, even in a form in which the surface of the skin plate or the skin plate is not provided, a resin layer may be provided on the outermost surface of the synthetic segment to improve the wear resistance and water stop performance of the segment.
As the resin constituting the resin layer, polyacetal resin, polyamide resin, polytetrafluoroethylene resin, polyurea resin, and the like can be applied, but any of them requires countermeasures against surface wear by the table brush of the shield machine.

A supplementary explanation of the inner surface water blocking material 81 will be given. The inner surface water blocking material 81 has adhesion to the steel shell 6 and the concrete 60. Specifically, the inner surface water blocking material 81 has an adhesive force of 1.5 MPa or more with respect to both the steel shell 6 and the concrete 60 as adhesiveness. When the inner surface water blocking material 81 has such adhesion, the binding force between the steel shell and the concrete can be increased. In the present disclosure, the “adhesion force” can be measured as follows, for example. An inner surface water blocking material is applied with a predetermined thickness (for example, 1 mm or more) to a test piece (for example, a flat plate) formed of a material to be adhered (steel shell or concrete). A tensile jig having a predetermined adhesion area with respect to the test piece is attached to the test piece via the inner surface water stop material so that the inner surface water stop material adheres to the entire attachment area. Pull the tension jig perpendicular to the specimen so as to pull the tension jig away from the specimen. During the pulling, the tensile force acting between the test piece and the tension jig is measured using a known measuring device. The “adhesion force” (N / mm ² (= MPa)) is measured by dividing the tensile force (N) when the tensile jig is pulled away from the test piece by the adhesion area (mm ² ).

  Further, the inner surface water-stopping material 81 has followability to deformation at the interface between the steel shell 6 and the concrete 60. In the present disclosure, “deformation at the interface between the steel shell and the concrete” may mean a relative displacement between the steel shell 6 and the concrete 60. “Followability” can mean that the inner surface water blocking material can be deformed by the above relative displacement without breaking. Specifically, the inner surface water blocking material 81 has a breaking elongation of 400% or more as followability. When the inner surface water blocking material 81 has such followability, high water blocking performance can be obtained. In the present disclosure, the “elongation at break” (%) is the permanent elongation after breakage when a general tensile test is performed using a test piece (for example, a dumbbell-shaped test piece) made from a waterstop material. (Lu-L0) can be expressed as a percentage of the original mark distance L0. L0 is a mark distance marked on the test piece measured before the test, and Lu is a mark distance marked on the test piece measured after breaking.

  Further, the inner surface water blocking material 81 has a water blocking property for preventing liquid from passing between the steel shell 6 and the concrete 60. Such water blocking is designed to withstand various pressures applied to the inner surface water blocking material 81.

  The inner surface water blocking material 81 having the adhesive force, the followability, and the water blocking property as described above can be formed of various materials. For example, the inner surface water-stopping material 81 is an epoxy resin, polyurethane resin, fluororesin, acrylic rubber resin, polybutadiene rubber resin, chlorobrene rubber resin, chlorosulfonated polyethylene resin, resin mortar, fiber reinforced mortar, and non- Including at least one of vulcanized butyl rubber, as well as composite materials from some of these materials (eg, materials formed by laminating several layers of the above materials). it can. Further, the inner surface water blocking material 81 can have a property of adhering to the ready-mixed concrete as the ready-mixed concrete hydrates, when the concrete 60 is placed. The inner surface water blocking material 81 can be in a form that can be applied or applied, for example. In addition, the outer periphery water blocking material 82 may be the same material as the inner surface water blocking material 81 as described above.

  FIG. 12 is a schematic diagram illustrating a synthetic segment including a fixing member and a slip stopper. The synthetic segment 1 can include a fixing member 65 and a detent 66. The fixing member 65 is provided on the inner surface of the steel shell 6 (main girder steel plates 31 and 32 in FIG. 12), and is configured to prevent the steel shell 6 and the concrete 60 from being separated. In the present disclosure, “peeling” may mean that the steel shell 6 and the concrete 60 are peeled from each other and a gap is formed between the steel shell 6 and the concrete 60. The fixing member 65 protrudes from the inner surface of the steel shell 6. In FIG. 12, the fixing member 65 has an L shape. However, in other embodiments, the fixing member 65 can take various shapes that can prevent the concrete 60 from moving away from the steel shell 6, such as a T-shape. The fixing member 65 can be formed of various materials such as metal.

  The slip stopper 66 is provided on the inner surface of the steel shell 6 and is configured to prevent a shift between the steel shell 6 and the concrete 60. In the present disclosure, “displacement” may mean that the steel shell 6 and the concrete 60 slide with each other along the interface therebetween (along at least one of the Y direction and the Z direction). The slip stopper 66 may be a relatively large unevenness as shown in FIG. 12, for example. In FIG. 12, only the stopper 66 for preventing the shift in the Z direction is shown, but a stopper (not shown) for preventing the shift in the Y direction is provided along the direction perpendicular to the paper surface. Also good. In other embodiments, the stopper 66 may be uneven as obtained by roughening such as blasting.

  Next, the manufacturing method of the above synthetic segments 1 is demonstrated.

  (A)-(e) of FIG. 13 is a schematic diagram which shows the manufacturing method of a synthetic segment. In the present embodiment, a synthetic segment 1 having a steel shell 6 only on the main girder surface 3 as shown in FIG. 4 will be described. Therefore, the steel shell 6 has only the main girder steel plates 31 and 32.

  FIG. 13A shows the inner surfaces of the main girder steel plates 31 and 32. In this manufacturing method, first, at least one (two in this embodiment) inner surface water blocking material 81 is disposed on the inner surfaces of the main girder steel plates 31 and 32. Specifically, the inner surface water blocking material 81 is stuck in the inner surface water blocking groove 101. By sticking the inner surface water stop material 81 in the inner surface water stop groove 101, it is possible to more reliably prevent a passage through which liquid can pass between the main girder steel plates 31 and 32 and the concrete 60 from being formed. Can do. Moreover, the inner surface water-stopping material 81 is sufficient up to the joint surface side ends of the main girder steel plates 31 and 32 (the left and right ends in FIG. 13A) so as to be connected to the outer peripheral water-stopping material 82 described later. Is pasted.

  13B, 13C, and 13D are schematic cross-sectional views along the height direction Z and the circumferential direction Y of the composite segment 1. FIG. With reference to FIG.13 (b), in this manufacturing method, the main girder steel plates 31 and 32 are installed so that it may mutually oppose on the upper surface 22 of the casting mold 20 then. It should be noted that FIG. 13B shows only one main girder steel plate 31 (the same applies to FIGS. 13C and 13D). Specifically, in the present embodiment, the upper surface 22 of the casting mold 20 is configured to come into contact with the inner space side surface of the composite segment 1, and thus the upper surface 22 has a convex arcuate surface shape. Presents. Thereby, during the production of the composite segment 1, the casting mold 20 is arranged so that the composite segment 1 is held upward (in a reverse boat shape) and the four corners of the composite segment 1 are aligned horizontally. The synthetic segment 1 can be supported (so-called “striking”). Further, as described above, since the steel shell 6 has only the main girder steel plates 31 and 32 in the present embodiment, the auxiliary mold is formed on the upper surface 22 of the casting mold 20 so as to define a space filled with the concrete 60. The frames 21 and 21 are arranged so as to face each other. Each auxiliary mold 21 is arranged so as to connect corresponding ends of the main girder steel plates 31 and 32. For example, in the embodiment in which the steel shells 6 (corner steel plates 5) are disposed only at the four corners of the composite segment 1 as shown in FIG. In addition, the auxiliary formwork 21 can be arranged on each main girder surface 3 and each joint surface 4. Further, for example, in the embodiment in which the steel shell 6 is arranged over the entire circumference of the main girder surface 3 and the joint surface 4 as shown in FIG. 2, the auxiliary formwork 21 shown in FIG. 21 is not necessary. Thus, those skilled in the art can understand that the necessary auxiliary mold 21 can be arranged according to the form of the steel shell 6.

  With reference to FIG.13 (c), the reinforcing bar 64 and the connection material 61 are installed inside the steel shell 6 (main girder steel plates 31 and 32) continuously. For example, the connecting member 61 may be fixed to the main girder steel plates 31 and 32 by known fixing means such as welding. For example, as shown in FIG. 6D, the reinforcing bars 64 may be arranged through an opening 63 provided in the connecting member 61. Referring to FIG. 13 (c), the curing material 23 is then replaced with the main girder steel plates 31, 32 and the auxiliary so as to block the space surrounded by the main girder steel plates 31, 32 and the auxiliary molds 21, 21 from above. It arrange | positions at the upper end of the formwork 21 and 21. FIG. When the skin plate 9 is used, the skin plate 9 may be disposed in place of the curing material 23.

  Referring to FIG. 13 (d), subsequently, the ready-mixed concrete is inserted from the opening 24 provided in the central portion of the curing material 23, and the casting mold 20, the main girder steel plates 31 and 32, the auxiliary mold 21, The space defined by 21 and the curing material 23 is filled with ready-mixed concrete. As a result, the concrete 60 is placed. After the curing of the concrete 60 is completed, the composite segment 1 is demolded. It should be noted that the ready-mixed concrete may be filled without using the curing material 23.

  FIG. 13E shows the outer surfaces of the main girder steel plates 31 and 32. Subsequently, at least one (two in this embodiment) outer peripheral water blocking material 82 is disposed on the outer surface of the main girder steel plates 31 and 32. Specifically, the outer peripheral water blocking material 82 is stuck in the outer peripheral water blocking groove 100. More specifically, as described above, since the composite segment 1 has the steel shell 6 only on the main girder surface 3 in the present embodiment, the joint surface 4 is composed of concrete 60 (see, for example, FIG. 4). ). Accordingly, the auxiliary molds 21 and 21 are provided with convex portions corresponding to the outer peripheral water stop grooves 100, and the joint surface 4 has the outer peripheral water stop grooves 100 on the concrete 60 and the convex portions of the auxiliary mold frames 21 and 21. Is formed by. Moreover, the same outer periphery water stop groove | channel 100 is previously formed also in the end surface of the main girder steel plates 31 and 32 (illustration omitted). And the outer periphery water stop material 82 is arrange | positioned in the outer periphery water stop groove | channel 100. FIG. As described above, since the inner surface water-stopping material 81 is sufficiently pasted to the joint surface side ends of the main girder steel plates 31 and 32, the outer peripheral water-stopping material 82 is joined to the inner surface water-stopping material 81. . The synthetic segment 1 is manufactured by the above steps.

  A person skilled in the art can understand that the manufacturing method of the synthetic segment 1 does not have to be performed in the above order, and can be performed in other orders as long as no technical contradiction arises. For example, a step (FIG. 13 (a)) of disposing an inner water blocking material 81 on the inner surface of the steel shell 6, a step (FIG. 13 (b)) of installing the steel shell 6 on the casting mold 20, and a steel shell. The step of installing the reinforcing bars 64 and the connecting member 61 in FIG. 6 (FIG. 13C) need not be performed in this order, and may be performed in a different order.

  Moreover, in said embodiment, the synthetic segment 1 is manufactured by the beating. In the case of upturning, the inner surface of the concrete 60 comes into contact with the upper surface 22 of the casting mold 20, so that the inner surface of the concrete 60 visible from the inside of the tunnel can be formed smoothly. it can. However, the synthetic segment 1 may be manufactured by other placement methods.

  For example, the synthetic segment 1 may be manufactured by boat-shaped driving. In this case, the upper surface 22 of the casting mold 20 is configured so as to contact the ground-side surface of the composite segment 1 as opposed to the boat-shaped driving, and therefore the upper surface 22 is a concave arcuate surface. Presents a shape. Thereby, during manufacture of the synthetic segment 1, the casting mold 20 is synthesized so that the synthetic segment 1 is held downwardly convex (in a boat shape) and the four corners of the synthetic segment 1 are aligned horizontally. Support segment 1. Other points can be similar to the beating.

  Further, for example, the composite segment 1 may be placed by oblique installation. In this case, the auxiliary formwork is installed with one joint surface 4 on the upper side and the other joint surface 4 on the oblique lower side. The inner surface is placed so that the surface is diagonally upward, and the casting mold is also installed on this surface, and the casting mold 20 is installed so that the ground side is diagonally below, It can be placed in the same manner as above. And concrete can be cast from the upper joint surface 4 or its vicinity. In this case, concrete can be placed without problems by placing fluidized concrete or the like. The other points can be the same as face down.

For example, the synthetic segment 1 may be manufactured by centrifugal driving. in this case,
The placement mold 20 has, for example, a ring shape. The casting mold 20 is configured to support a plurality of composite segments 1 arranged in a ring shape on the inner peripheral surface thereof, and to contact a ground-side surface of the plurality of composite segments 1. In centrifugal casting, after the inner surface water blocking material 81 is disposed on the inner surface of the steel shell 6, the steel shells 6 of the plurality of composite segments 1 are installed in a ring shape on the inner peripheral surface of the casting mold 20. Further, a necessary auxiliary mold 21 is arranged according to the form of the steel shell 6. Under the present circumstances, the reinforcing bar 64 and the connection material 61 may be installed in the steel shell 6 inside the steel shell 6 as needed. Subsequently, the casting mold 20 is rotated around the center axis of the ring-shaped casting mold 20, and the inner peripheral surface of the casting mold 20 is moved from a predetermined position inside the casting mold 20. The ready-mixed concrete is discharged toward a predetermined position. By the centrifugal force caused by the rotation, the concrete is filled inside each steel shell 6, and the concrete 60 is placed inside each steel shell 6. After the curing of the concrete 60 is completed, the rotation of the casting mold 20 is stopped, and each composite segment 1 is demolded. Then, the outer periphery water stop material 82 is affixed in the outer periphery water stop groove | channel 100 of the outer peripheral surface of the steel shell 6. FIG. In the case of such centrifugal placement, the ground-side surface of the concrete 60 comes into contact with the inner peripheral surface of the casting form 20, so that the ground-side surface of the concrete 60 can be formed smoothly.

If the composite segment according to the present invention is adopted in the construction of a shield tunnel,
・ Applicable to deep tunnels with high groundwater pressure
・ It can be applied to deep tunnels with large load and cross-sectional force, large cross-section tunnels, or non-circular cross-section tunnels.
・ High water-stop performance can be expected for a long period of time, so the life of the tunnel can be extended.
・ By increasing the binding force between the steel shell and concrete, it prevents cracks in the concrete during earthquakes or internal water pressure acting on tunnels such as underground rivers.
And the production cost of the composite segment can be reduced. Therefore, a great effect can be expected in the reduction of the initial cost and the maintenance cost for infrastructure development.

DESCRIPTION OF SYMBOLS 1: Synthetic segment 20: Casting formwork 21: Auxiliary formwork 22: Upper surface of casting formwork 23: Curing material 24: Opening of hardening material 3: Main girder surface 31: One end side main girder steel plate 32: Other end side Main girder steel plate 4: Joint surface 41: Joint steel plate on one end 42: Joint steel plate on the other end 5: Corner steel plate 6: Steel shell 6a: Inside the frame (space)
60: Concrete 61: Connecting material 63: Opening 64: Reinforcing bar 65: Fixing material 66: Non-slip 7: Tunnel 70: Segment ring 8: Water stop material 81: Internal water stop material 82: Outer water stop material 9: Skin plate 100 : Outer periphery water stop groove 101: inner surface water stop groove

Claims (15)

A method for producing a synthetic segment for a tunnel having concrete, a steel shell and a waterstop material,
The steel shell is disposed on at least a part of an outer peripheral surface composed of a main girder surface that is an end surface on the axial direction side of the tunnel of the composite segment and a joint surface that is an end surface on the circumferential direction side of the tunnel,
The manufacturing method is
Disposing at least one inner surface water blocking material on the inner surface side of the steel shell relative to the concrete;
Installing the steel shell in a casting formwork;
Installing a rebar inside the steel shell;
Placing concrete inside the steel shell;
After demolding, placing an outer peripheral water stop material over the entire circumference of the main girder surface and the joint surface of the synthetic segment;
A method for manufacturing a synthetic segment. An inner water stop groove is provided on the inner surface of the steel shell,
The step of disposing the at least one inner surface water blocking material includes disposing the at least one inner surface water blocking material in the inner surface water blocking groove.
The manufacturing method of the synthetic segment of Claim 1. The casting mold is configured to support the composite segment so that the four corners of the composite segment are aligned horizontally, and to contact a ground-side surface of the composite segment.
The manufacturing method of the synthetic segment of Claim 1 or 2. The placement mold is configured to support the composite segment so that the four corners of the composite segment are aligned horizontally, and to contact the inner space side surface of the composite segment.
The manufacturing method of the synthetic segment of Claim 1 or 2. The casting mold form supports the composite segment diagonally so that one joint surface of the composite segment is higher than the other joint surface, and the inner space side surface or ground of the composite segment. Configured to contact the mountain side surface,
The manufacturing method of the synthetic segment of Claim 1 or 2. The placement mold is configured to support a plurality of composite segments arranged in a ring shape, and to be in contact with the outer peripheral surface on the ground mountain side of the plurality of composite segments,
The step of placing concrete on the casting formwork comprises rotating the casting formwork around a center axis of the ring and starting from a predetermined position inside the casting formwork. The method for producing a synthetic segment according to claim 1, comprising discharging the ready-mixed concrete toward a predetermined position on the inner peripheral surface of the composite segment. The steel shell is disposed only on a part of the outer peripheral surface composed of the main girder surface and the joint surface,
The manufacturing method is
The said placing formwork further comprises the step of installing an auxiliary formwork at a position where the steel shell is not disposed in the outer peripheral surface constituted by the main girder surface and the joint surface. The manufacturing method of the synthetic segment of any one of these.   The at least 1 outer periphery water stop groove is provided in the main girder surface and joint surface of the synthetic segment, and the outer periphery water stop material is disposed in the outer periphery water stop groove. A synthetic segment manufacturing method. The crack strength of the concrete, the elastic reaction force of the inner surface water blocking material, and the water pressure acting from the outside of the tunnel satisfy the following relational expression. A method for producing the described synthetic segment.
(Concrete crack strength)> (Internal waterstop elastic reaction force)> (Water pressure acting on the tunnel)   The method for manufacturing a synthetic segment according to any one of claims 1 to 9, wherein an end portion of the inner surface water-stopping material and the outer peripheral water-stopping material are arranged in contact with each other.   The steel shell is arrange | positioned at both the main girder surfaces of the said synthetic segment, The connection material which connects the said steel shells, The said reinforcement is arrange | positioned in contact with this connection material, The any one of Claim 1 thru | or 10 The manufacturing method of the synthetic segment as described in a term.   The manufacturing method of the synthetic segment of Claim 11 with which the said connection material is contact | abutted and provided in both the natural ground side and inner space side of the said reinforcing bar.   The method for producing a synthetic segment according to any one of claims 1 to 12, wherein at least a part of the water-stopping material is a water-swellable water-stopping material.   The method for producing a synthetic segment according to any one of claims 1 to 13, wherein the outer periphery water-stopping material is a water-swellable water-stopping material, and the inner surface water-stopping material is a non-water-swelling water-stopping material.   One or more of the main girder surface and joint surface of the synthetic segment is the steel shell provided with a corrugated surface having a concavo-convex portion, and the concave portion of the corrugated surface is an outer circumferential water stop groove or an inner surface. It is a water stop groove, The manufacturing method of the synthetic segment of any one of Claim 1 thru | or 14.