JP7215252B2 - Synthetic segment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a segment used in tunnel construction, particularly tunnel construction using the shield tunneling method. More particularly, it relates to a composite segment with a steel shell filled with concrete.

In addition to mountain tunnels and undersea tunnels, underground roads in urban areas that are difficult to construct in shallow depths, railway tunnels, sewage tunnels, underground river tunnels, etc., are excavated with a shield machine, and segments are created in the tunnels that have been excavated. A method of constructing a tunnel by connecting members with a fan-shaped cross section vertically and horizontally is adopted.

Whether the space inside the tunnel is used as a road or railroad, or as a rainwater channel or sewage system, there is a difference in water pressure and earth pressure acting on the inner and outer surfaces with the tunnel wall as the boundary. Therefore, the waterproof structure of the tunnel wall is an important issue when 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 lengthwise and breadthwise to form a tunnel wall, the water cutoff structure at the joints between segments (joints between segments) is considered to be the most important.

The water stop structure of the shield tunnel is
(a) Waterproofing by back-filling injection material located on the rear side of the segment, that is, on the rocky ground side,
(b) Waterproofing applied to the joint surface of the segment, and (c) Waterproofing by secondary lining applied inside the tunnel,
etc.

The main purpose of waterproofing with backfilling material is to equalize the water pressure acting on the tunnel structure by injecting an appropriate backfilling material to counter disturbance of the natural stratum during shield excavation.
On the other hand, water stoppage by secondary lining was the most common practice until recently. Therefore, it is difficult to expect a highly reliable water stopping effect.

A recent trend is to omit the secondary lining in many cases due to the improved reliability of the segment performance. It can be said that it depends on whether it can be implemented reliably.

In the method for manufacturing a synthetic segment described in Patent Document 1, in order to densify the peripheral edge of the concrete, instead of placing the steel shell in a convex shape downward when the concrete is poured, Placed in a convex shape, so-called laying down, is adopted, and at that time, a water stop member is placed around the concrete filling hole provided in the center of the segment on the ground side to improve water stoppage at the interface between the steel shell and concrete. and how to prevent water from entering between them.

Furthermore, in the technique disclosed in Patent Document 2, in a synthetic segment in which an outer shell having a frame member formed in a hollow frame shape and a concrete filling member formed in the outer shell are integrated a water stop member made of an elastic material fixed to the inner peripheral surface of the frame member is provided, and water is stopped between the inner surface of the frame member and the concrete by the water stop member; A technology is disclosed that can inexpensively manufacture a structure that exhibits high resistance against strong shearing force acting in the radial direction of the arc between the joints and that can stop water without providing a conventional skin plate.

JP 2014-88658 A JP 2014-88720 A

However, none of the above conventional techniques
・It cannot be said that the waterproof performance is sufficient.
・The elastic reaction force of the water cutoff material that satisfies the relational conditions of both water pressure and concrete strength tends to be insufficient.
・Because the steel shell that constitutes the outer shell receives the elastic reaction force of the water stop material, it deforms out of plane and separates from the concrete. , concrete slips out of the steel shell, making it impossible to demonstrate water stopping performance and segment mechanical performance as calculated.
・If the elastic reaction force of the water stop material is insufficient, it affects the binding force of the concrete by the steel shell, and the concrete is likely to be damaged by sliding.
・Therefore, application tends to be limited to shallow tunnels with low groundwater pressure.
・Applicability is limited to shallow tunnels, small cross-section tunnels, or circular tunnels where the load applied to the segment is small and uniform, and non-uniform loads are applied due to large load loads such as deep tunnels and tunnel cross-sections. difficult to apply to non-circular tunnels,
and other drawbacks.

The present invention provides a joint surface between the steel shell and concrete of a synthetic segment used in the construction of a shield tunnel, etc., with high water stop performance, and enhances the binding force of the steel shell to the concrete, so that the steel shell and concrete are integrated. The goal is to improve the waterproofness between adjacent segments at the same time, and to provide a synthetic segment that can be applied to large-depth or non-circular cross-section tunnels where high loads or uneven loads are applied. and

The inventors of the present invention conducted various studies in order to improve the segment strength and water stopping performance, and as a result,
・Improve the water stopping performance of the interface between the steel shell and concrete in the composite segment.
・At the same time, the water stopping performance at the joint surface between adjacent synthetic segments is enhanced,
・Realize the elastic reaction force of the water stop material that satisfies the relational conditions of both water pressure and concrete strength,
・Increase the binding force of the steel shell to the concrete, and prevent the concrete from slipping out of the steel shell due to the action of abdominal pressure.
We have reached the knowledge that we can exhibit excellent segment strength and water stopping performance by doing so.

The synthetic segment according to the present invention, in which the above findings are realized,
・It can be applied to deep tunnels with high groundwater pressure,
・It can be applied to deep tunnels with large loads and cross-sectional forces, large cross-section tunnels, and non-circular cross-section tunnels.
・Because high water stopping performance can be expected for a long period of time, the life of tunnels can be extended and maintenance costs can be reduced.
・By increasing the binding force between the steel shell and concrete, cracking of concrete during an earthquake or cracking due to internal water pressure acting on tunnels such as underground rivers is prevented.
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 synthetic segment for a tunnel comprising concrete, a steel shell, and a water stop material, wherein the steel shell comprises a main girder surface, which is an end surface of the synthetic segment on the axial side of the tunnel, and a circumferential side of the tunnel. At least one outer peripheral water stop groove is provided on the main girder surface and the joint surface of the composite segment, and an outer peripheral water stop groove is provided in the outer peripheral water stop groove. A water material is arranged, and at least one inner water stop material is arranged on the inner surface side of the steel shell with respect to the concrete, and the inner water stop material has adhesion to the steel shell and the concrete, and adhesion to the steel shell. A synthetic segment having deformation compliance at the interface with the concrete.

(2) The inner surface water stop material has an adhesive force of 1.5 MPa or more to the steel shell and the concrete as the adhesiveness, and a breaking elongation of 400% or more as the followability. (1) The synthetic segment described in (1).

(3) The inner water stop material includes epoxy resin, polyurethane resin, fluorine resin, acrylic rubber resin, polybutadiene rubber resin, chloroprene rubber resin, chlorosulfonated polyethylene resin, resin mortar, fiber-reinforced mortar, and A synthetic segment according to (1) or (2), comprising at least one of unvulcanized butyl rubber, and composites of some of these materials.

(4) The synthetic segment according to any one of (1) to (3) above, wherein the inner surface of the steel shell is provided with a fixing material for preventing separation between the steel shell and the concrete.

(5) The synthetic segment according to any one of (1) to (4) above, wherein the inner surface of the steel shell is provided with a slip stopper for preventing slippage between the steel shell and the concrete.

(6) The composite segment according to any one of (1) to (5), wherein the steel shell is arranged only on a part of the outer peripheral surface composed of the main girder surface and the joint surface. .

(7) The above (1) to (6), wherein the cracking strength of the concrete, the elastic reaction force of the inner water stop material, and the water pressure acting on the tunnel satisfy the following relational expressions: A synthetic segment according to any of the preceding.
(Concrete cracking strength) > (Inner water stop material elastic reaction force) > (Water pressure acting on the tunnel)

(8) The synthetic segment according to any one of (1) to (7) above, wherein the inner water-stopping material is arranged in an inner water-stopping groove provided on the inner surface of the steel shell.

(9) The synthetic segment according to any one of (1) to (8), wherein the end portion of the inner surface water-stopping material and the outer peripheral water-stopping material are arranged in contact with each other.

(10) The steel shells are arranged on both main girder surfaces of the composite segment, and the connecting members that connect the steel shells and the reinforcing bars are arranged in contact with the connecting members. 9) A synthetic segment according to any one of 9).

(11) The composite segment according to (10) above, wherein the connecting member is provided in contact with both the natural ground side and the hollow side of the reinforcing bar.

(12) The synthetic segment according to any one of (1) to (11) above, wherein at least part of the water-stopping material is a water-swellable water-stopping material.

(13) The synthetic segment according to any one of (1) to (12) above, wherein the outer peripheral 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.

(14) At least one of the main girder surface and the joint surface of the composite segment is the steel shell having a corrugated surface having uneven portions, and the concave portions of the corrugated surface are water stop on the outer periphery. The synthetic segment according to any one of the above (1) to (13), which is a groove or a water stop groove on the inner surface of the steel shell.

The present invention is a composite that has excellent water tightness performance and binding force between the steel shell and concrete, continues water stopping performance at the joints of the segments for a long period of time, and has a large resistance to the load on the inner and outer surfaces. Regarding segments, it not only improves the integrity of the steel shell and concrete, but also improves the water stoppage between adjacent synthetic segments, making it possible to apply to large-depth, large-section, and non-circular section shield tunnels. It provides a segment.

FIG. 11 is a perspective view showing a tunnel constructed of segments; FIG. 3 is a perspective view of the synthetic segment of the present invention in which the entire main girder surface and joint surface are made of a steel shell. FIG. 2 is a perspective view of a synthetic segment of the present invention in which the four corners are steel shells, and an enlarged view of the steel shells. FIG. 2 is a conceptual diagram of a case where the main girder surface of the synthetic segment of the present invention is a steel shell. FIG. 4 is a conceptual plan view showing a connection structure between an inner surface water-stopping material and an outer peripheral water-stopping material in the synthetic segment of the present invention; FIG. 4 is a cross-sectional view showing a connecting structure between connecting members and reinforcing bars that connect the main girder surfaces of the present invention. FIG. 3 is a schematic diagram showing a state in which concrete placing pressure acts on non-swelling and swelling water stop materials. It is a graph which shows the relationship between concrete crack strength, concrete placing pressure, and design water pressure. FIG. 4 is a conceptual diagram when the swelling property of the water stop material on the main girder surface is changed. FIG. 3 is a schematic diagram of a configuration in which a corrugated shape that can be fitted to joint surfaces of a main girder steel plate, a joint steel plate, or the like is provided. 11 is an enlarged view of part A in FIG. 10; FIG. FIG. 10 is a schematic diagram showing a composite segment with anchors and shears; (a) to (e) are schematic diagrams showing a method for producing a synthetic segment.

The present invention will be specifically described below.
In the composite segment of the present invention, as shown in FIG. 1, a tunnel 7 is constructed by connecting a plurality of composite segments 1 in the axial direction X of the tunnel cross section and the circumferential direction Y of the tunnel cross section. .

The tunnel 7 is provided in an excavation hole formed by excavating the natural ground by the shield construction method. In the example shown in FIG. 1, the segment ring 70 with 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 cuts off the natural ground outside the tunnel 7 (in the Z1 direction), forming an inner space inside the tunnel 7 (in the Z2 direction).

As shown in FIG. 2, the composite segment comprises a pair of main girder surfaces 3, 3 that define the outer shape of the tunnel cross section, and the ends of the pair of main girder surfaces that are connected to each other in the circumferential direction of the tunnel cross section. It is configured in a curved rectangular shape with a pair of joint surfaces 4, 4 which define the joint surface with the synthetic segment adjacent to it.

In the present invention, the four sides that define the outer shape of the composite segment are referred to as main girder surfaces or joint surfaces, regardless of whether they are formed of steel or concrete molding surfaces.
In the embodiment 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, 32 and joint steel plates 41, 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 stages 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 constrained and the water stop effect is enhanced. Similarly, the water stopping effect can be improved by installing the inner water stopping material 81 with an inner water stopping groove.
When manufacturing a composite segment of this form, the steel shell 6 formed by the main girder steel plate and the joint steel plate is placed on a semi-cylindrical formwork base that defines the inner surface side of the tunnel, and the ground side is defined. The inside of the frame 6a is filled with concrete 60 to form a synthetic segment composed of a rectangular steel shell and concrete. In addition, the steel shell 6 may be provided on at least one of the main girder surfaces 3, 3 and the joint surfaces 4, 4. In that case, by using a formwork that constrains the main girder surfaces or the joint surfaces, concrete Fill 60. In addition, the inner water stop material 81 may be installed on the steel shell 6 in advance before placing the concrete, and the outer water stop material 82 may be installed after removing the formwork.

<Variations of concrete>
As the type of concrete 60, in addition to normal concrete, non-shrink concrete or concrete to which an appropriate expansive agent is added may be selected to improve the filling rate of concrete.

<Regarding variations in the form of the steel shell>
In the embodiment shown in FIG. 2, all of the main girder surfaces and joint surfaces that define the rectangular outer surface of the segment are made of steel plates. , Only the corner portions (four corner portions) of the composite segment where the main girder surface and the joint surface are in contact with each other may be formed of the corner steel plates 5 . In this example, the inner water stop material 81 and the outer water stop material 82 are arranged in a single layer at the center of the composite segment in the height direction (Z direction). are installed in the inner water stop groove 101 and the outer water stop groove 100 provided at the same position in the height direction (Z direction) of the composite segment on both sides of the corner steel plate 5 .

By making only the corners made of steel shell, it is possible to reduce the weight of the synthetic segment, and during segment construction, contact and collision with the existing segment part easily cause defects such as cracks and chips. It is possible to improve the strength of the corner portion of the segment. Furthermore, it is possible to appropriately improve the water stopping performance at the corner portions of the segments, which are the weakest points in the water stopping performance at the joint surfaces of the adjacent synthetic segments.

Alternatively, only the main girder surface 3 may be formed of main girder steel plates 31 and 32, as shown in FIG. 4(a). As shown in the AA cross section in FIG. They are arranged in pairs in the cutoff grooves 100 and 101 provided in the same position in the longitudinal direction (Z direction) and facing the inner and outer surfaces of the steel shell, improving the water cutoff at the interface between the steel shell and concrete. At the same time, the water stoppage between the adjacent segments is also improved. On the other hand, as shown in FIG. 4(c), on the joint surface formed of concrete without the steel shell, the outer peripheral water stop material 82 and the inner surface water stop material 81 of the main girder surface 3 are located at the same position in the Z direction. Only the outer peripheral water stop material 82 is arranged in two stages in the thickness direction of the synthetic segment in the water stop groove 100 provided in the . FIG. 4(d) is an enlarged cross-sectional view of a water stop groove provided in the steel shell of the main girder surface and a water stop material arranged in the groove.

On the other hand, it is also possible to employ the steel shell only on the joint surfaces of the synthetic segments.

In either case, the inner water stop material is installed on the inner surface of the steel shell that contacts the concrete, and the outer peripheral surface of the segment is continuously formed across the steel shell and the concrete surface. 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 inner surface of the steel shell and concrete and the joint surface between adjacent synthetic segments. . The water pressure acting from the ground outside the tunnel acts on the segment ring and tries to form a channel on the joint surface between the inner surface of the steel shell and the concrete. While the waterway can be cut off by providing a water stop/waterproof structure that resists this, water pressure also acts on the joint surfaces of adjacent synthetic segments. Therefore, by aligning the height direction (Z direction) of the segments and arranging them in pairs, the outer and inner surfaces of the composite segment can be synergistically water-stopped and waterproofed. , can demonstrate excellent segment strength and water stop performance.

As conceptually shown in the plan view of FIG. Similarly, the inner water stop material 81 can also be formed continuously in a quadrilateral annular shape. At the partial end of the steel shell, the end of the inner water stop material 81 is extended toward the outer edge of the segment and is in contact with the outer water stop material 82 on the outer peripheral surface of the segment, so that the inner surface of the steel shell and the concrete It is possible to improve the water stop performance on the contact surface of.

That is, except for the configuration shown in Fig. 5(a), in which the main girder steel plates and the joint steel plates are used to form the entire outer circumference of the segment with a steel shell, the inner surface water stop material 81 consists of the main girder steel plates 31, 32 and the joint steel plates 41, 42. Alternatively, it is installed only on the inner surface of the steel shell formed by the corner steel plate 5, and at the end of each steel plate, the end extending toward the outer surface of the segment main body contacts the rectangular outer peripheral waterproof material 82 configured as This state is shown in FIGS. 5(b) to 5(d).
Specifically, as shown in the enlarged view of FIG. 3, the ends of the inner surface water stop material 81 are extended so as to protrude from the main girder surface and the joint surface formed by the filled concrete, This protruding portion may be folded inside the outer peripheral water-stopping material 82 attached later so that the end of the inner surface water-stopping material 81 contacts the outer peripheral water-stopping material 82 .

The inner surface water stop material 81 ensures the water stop performance of the joint surface between the inner surface of the main girder steel plate, the joint steel plate, or the corner steel plate and the concrete 60, and the change in load due to deterioration over time and earthquakes is prevented. Even if there is, the joint state between the steel shell and the concrete is maintained.

When using main girder steel plates and joint steel plates, the entire perimeter of the segment is formed from a steel shell, only the main girder surface is formed from steel plates, and only the joint surface is formed from steel plates. In order to improve the strength of the part and increase the adhesion between the steel shell and concrete, in addition to the normal reinforcing bar structure consisting of reinforcing bars extending in the direction of the main girder steel plate and reinforcing bars extending in the direction of the joint steel plate, connecting members can be installed to improve the strength of the segment itself and the bond strength between the steel shell and concrete. Furthermore, in the vicinity of the surface layer forming the ground surface and inner space of the composite segment, a grid-like member made of reinforcing bars or the like can be embedded for the purpose of preventing cracks on the concrete surface.

<Application of connecting materials and variation of reinforcing bar structure>
In the embodiment shown in FIG. 6, the main girder steel plates 31 and 32 are connected to each other by an axial connecting member 61 extending in the tunnel axial direction. In FIGS. 6(a) to 6(d), the left figure is a sectional view in a direction perpendicular to the main girder plane, and the right figure is a sectional view in a direction parallel to the main girder face.
In this embodiment, in FIG. 6A, a reinforcing bar 64 orthogonal to these connecting members is arranged on the tunnel space side (Z2 direction side) of the connecting member 61, and the water pressure of rainwater or the like filling the tunnel is increased. It increases the resistance to the expansion force (concrete pull-out force) exerted on the segment.

On the other hand, in the form shown in FIG. 6B, a reinforcing bar 64 is arranged on the ground side (Z1 direction side) of the similarly arranged connecting member 61, and the pressure (abdominal pressure) directed from the ground side toward the inner space of the tunnel (abdominal pressure) Increases endurance.

Furthermore, in another embodiment of the present invention, as shown in FIG. 6(c), connecting members 61 are provided to the reinforcing bars 64 arranged in the same manner on both the tunnel ground side and the tunnel inner space side, for example, alternately. By arranging it, it achieves high durability against both the pressure from the ground side and the internal pressure from the fluid etc. that fills the space inside the tunnel.

Furthermore, in another embodiment, as shown in FIG. 6(d) and its partial enlarged view, an opening 63 is formed in the connecting member, and a reinforcing bar 64 is passed through this hole, thereby increasing the concrete break-out force and abdominal pressure. Both can resist. Furthermore, even in a synthetic segment with a small design thickness, it is possible to realize a dense reinforcing bar structure while suppressing adverse effects on concrete placement, and the strength of the entire segment can be improved. Note that, instead of the opening 63, a notch may be provided for facilitating the positioning and fitting of the reinforcing bars.

The connecting member described above extends in the axial direction of the tunnel and connects the main girder steel plates, but a similar connecting member can also be arranged to connect between a pair of joint steel plates. That is, a connecting member having a curve similar to that of the main girder steel plate is arranged to connect a pair of joint steel plates in the circumferential direction, and reinforcing bars perpendicular to this are arranged on the tunnel space side of each connecting member in the circumferential direction, It can be arranged on the natural ground side, or on both the tunnel space side and the natural ground side. can be done.

Regarding the positional relationship between various connecting members and reinforcing bars, if the connecting members are placed outside the reinforcing bars, that is, on the ground side (Z1 direction side), high resistance can be exerted against the fluid pressure that fills the space inside the tunnel. If it is placed on the tunnel inner space side (Z2 direction side) of the reinforcing bar, it can exhibit high strength against the abdominal pressure from the natural ground side. Also, for example, if they are arranged alternately on both sides, a high resistance against pressure from both the inner and outer surfaces of the tunnel can be expected. These effects are due to the fact that the concrete is not constrained by the skin plate in the case of the so-called four-sided steel shell segment, which does not have a skin plate on the ground side of the tunnel and forms the steel shell with the main girder steel plate and the joint steel plate. becomes particularly important since
Furthermore, if the opening provided in the connecting member is penetrated or the notch is fitted, the reinforcing bar can be easily positioned and temporarily fixed, and the reinforcing bar structure, and thus the composite segment, can be easily designed to be thin. There are also advantages.

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

As the water-stopping material on the inner surface, in addition to the usual elastic rubber, water-swelling water-stopping material with an appropriate swelling speed can be used. Considering the elastic reaction force of the water stop material of the inner groove and the design water pressure of the tunnel constructed by the synthetic segment,
(Concrete cracking strength) > (Inner water stop material elastic reaction force) > (Water pressure acting on the tunnel)
It is necessary to appropriately set the material properties of concrete, the material properties of the water stop material, the dimensional specifications, etc. so that the relationship is satisfied. When the elastic reaction force of the inner water-stopping material is greater than the crack strength of the concrete, the concrete in contact with the inner water-stopping material is locally subjected to an excessively large amount of bearing pressure, causing the concrete to break and crack. , a channel is formed and causes water leakage. If the water pressure acting on the tunnel is greater than the elastic reaction force of the inner water-stopping material, the water-stopping effect of the water-stopping material is insufficient, causing water leakage.

<Setting the elastic reaction force of the inner water stop material>
Regarding the elastic reaction force of the water stop material installed in the inner groove of the inner 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 the manufacturing process of the composite segment. to decide.
That is, in the manufacturing process of the synthetic segment, when a water-swellable material is adopted as the waterproof material, as shown in FIG. When swelling pressure due to water absorption is applied, the water stop material maintains its shape against the concrete placing pressure, but this swelling pressure increases with the lapse of time as shown in FIG. In addition, the curing speed of concrete depends on the composition of the concrete and the curing method and curing time after placing the concrete. Taking these factors into consideration, considering the increase in swelling pressure due to moisture in the concrete, the material characteristics and size ( cross-sectional area and shape), etc.
For example, when the design standard strength of concrete is 42 MPa and the water pressure acting on the tunnel is 0.5 MPa, the cracking strength of concrete is 15 MPa when evaluated in terms of bearing pressure strength. Therefore, it is necessary to set the elastic reaction force of the inner water stop material within the range of 0.5 MPa<elastic reaction force<15 MPa. The material properties of the water stop material are set based on the compression rate, compression speed, and expansion speed when the material is compressed, and the material and shape are generally tested before manufacturing. It is desirable to confirm and set characteristics that satisfy the process. As an example, in the manufacturing process of synthetic segments, the expansion speed of the water stop material is adjusted according to the speed at which the initial strength of the concrete develops in 1 to 2 days from concrete placement to the manifestation of the initial strength of the concrete. By adjusting, the occurrence of cracks during the manufacturing process can be suppressed. If you want to increase the elastic reaction force in order to improve watertightness, set the expansion rate of the water stop material to be longer than the initial strength of the concrete and less than the cracking strength of the concrete. good. Also, in order to avoid excessive elastic reaction force to the concrete, it is preferable to set the compression ratio to about 40% or less. It is preferable to set the height of the water stop material to about 5 mm to 50 mm and the thickness of the water stop material to about 5 mm to 20 mm.

<About the waterproof structure of the joint surface of the segment>
As with the inner water stop structure, an outer 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 water stop material is installed in this groove. , forming a waterproof structure at the interface with the adjacent segment. By providing the outer peripheral water stop grooves continuously in this way, the water flow path is blocked and the water stop performance is improved.
In the examples shown in FIGS. 2 and 4, a sealing structure is formed when the outer peripheral water stop materials 82 are provided in two stages, upper and lower, with a distance in the segment height direction (Z direction) and joined to adjacent segments. I am trying to

The joints between the main girder steel plates 31, 32 and the joint steel plates 41, 42 are also watertightly joined by welding, etc. Due to the fact that the inner surface water stop material is installed, and furthermore, the outer peripheral water stop material installed on the outer peripheral surface (joint surface) of the synthetic segment provides a seal structure at the joint surface between the segments, etc. A highly waterproof structure can be constructed between the inner and outer surfaces of the completed tunnel.

<Variation of inner water stop material>
When manufacturing the synthetic segment according to the present invention, especially when filling with concrete, the joint surfaces at both ends of the segment in the circumferential direction are placed on the floor instead of placing the center of the outer side surface of the segment on the floor. It is preferable to fill concrete by so-called laying down. In the case of pitting, since the concrete is placed on the semi-cylindrical form base that defines the inner surface of the tunnel, the finishing treatment of the concrete surface on the inner surface of the tunnel is not required, and the manufacturing cost can be reduced. In addition, by adopting laying down, the concrete in the vicinity of the joint surface portion forming the joint surface of the adjacent segment becomes dense due to the high filling pressure, which contributes to the improvement of the strength of the completed tunnel.

As mentioned above, when placing concrete, the inner water stop material is placed in the groove on the inner surface of the steel shell and filled with concrete. In contrast to the fact that concrete filling pressure begins to be received in a short time after the start of concrete filling and increases as filling progresses, the inner water stop material near the center of the segment main body is , will be subject to a relatively small filling pressure.

In order to cope with the imbalance of the filling pressure described above, 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 using a water-swelling material for the inner water-stopping material installed on the main girder surface, a water-stopping material with a relatively low swelling rate is used for the parts near the joint surfaces on both sides, and the center part of the segment is In view of the fact that the start of contact with the moisture contained in concrete is slow, by using a water-stopping material that swells relatively quickly, the degree of swelling of the water-stopping material installed on the inner surface of the main girder surface is The waterproof structure between the steel shell and the concrete can be made uniform over the entire inner surface of the main girder surface regardless of the location. Based on the same concept, a material with a relatively small amount of swelling or swelling pressure should be used as a water stop material near the joint surfaces on both sides, and a material with a relatively large amount of swelling or swelling pressure should be used in the center of the segment. can also

In the above-described embodiment, as different water-stopping materials, materials with different swelling speeds are used. By using a water-swellable material for the portion, similarly, depending on the presence or absence of swelling properties, the waterproof performance between the steel shell and the concrete can be improved as a whole segment.
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 properties are changed at the center 1/3 and both ends of the main girder surface.
The water pressure of the tunnel acts directly on the interface between adjacent segments. In addition, external force acting on the tunnel may cause misalignment or opening of the joint surfaces of adjacent segments. By providing the material, the manufacturing cost can be suppressed by adopting a non-water-swelling water stop material on the inner surface side where the gap with the concrete is not large compared to the outer peripheral surface.

<About the shape of the composite segment connection surface>
The connecting surfaces between the composite segments, that is, the connecting surfaces between the main girder surfaces and the joint surfaces, are not simply flat plates. A stronger connection surface can be provided, and the watertight connection between the segments can be enhanced. At the same time, between the steel shell and the concrete, the concrete is densely filled into the concave and convex shape of the fitting, so that the water stoppage and integrity are simultaneously enhanced, 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. 10 can be employed for the connecting surfaces. This main girder steel plate has a shape in which the inner and outer surfaces of the steel plates are fitted together. By inverting the inner and outer surfaces of a pair of main girder steel plates, the main girder steel plates are fitted with one type of cross-sectional shape. Since the girder surface can be formed and the concave-convex space can be formed in the fitting portion, it is rational and the manufacturing cost can be reduced.

In this example, corrugated fitting uneven portions are provided on the rock ground side and the tunnel space side of the composite segment, respectively, and when the synthetic segments are connected to each other, each fitting uneven portion has a pair of outer circumference water stop. Material 82 is installed.

The outer peripheral waterproof material 82 may be a simple elastic body or a swelling elastic body. In either case, as shown in the enlarged view of FIG. The shape and size must be determined so as to form a space where + (swelling deformation) is possible.

Similarly, on the inner surface side of the steel shell that contacts the concrete, the recesses of each fitting uneven part can be used as they are as water stop grooves. sexuality increases. In addition, since the convex portion functions as a slip stopper that resists slippage of the concrete in the segment height (Z) direction, the load bearing performance of the composite segment is dramatically improved.

<About waterproofing of the outer surface opening>
In addition to the fitting concave and convex surfaces described above, the main girder surfaces and joint surfaces that form the four sides of the composite segment may be provided with a bolting structure or other fitting structure for connecting to adjacent segments. be.
To accommodate these structures, the surfaces of the main girder or joint faces of the segments are provided with open holes.
The connecting structure itself with the adjacent segments is arranged in the opening hole, and if moisture etc. enters this part and rusts, the connecting strength of the segments will be impaired, and the tunnel itself will have a very serious problem in terms of strength. Therefore, an inner water-stopping material or an outer water-stopping material may be annularly installed around the opening to prevent moisture from entering the opening and prevent the connecting joint structure from rusting.

In the present invention, as shown in FIG. 2, a skin plate 9 made of a thin steel plate can be arranged on the natural ground side of the synthetic segment to enhance the outer surface strength and water stopping performance of the synthetic segment.
Further, a resin layer may be provided on the outermost surface of the synthetic segment to improve the abrasion resistance and water stop performance of the segment, even in the surface of the skin plate or in the form without the skin plate.
Polyacetal resin, polyamide resin, polytetrafluoroethylene resin, polyurea resin, and the like can be used as the resin constituting the resin layer.

A supplementary description of the inner water stop material 81 will be given. The inner surface water stop material 81 has adhesion to the steel shell 6 and the concrete 60 . Specifically, the inner surface water stop material 81 has adhesion of 1.5 MPa or more to both the steel shell 6 and the concrete 60 as adhesion. Since the inner water stop material 81 has such adhesiveness, it is possible to increase the binding force between the steel shell and the concrete. In the present disclosure, "adhesion" can be measured, for example, as follows. A test piece (for example, a flat plate) made of a material to be adhered (steel shell or concrete) is coated with an inner surface waterproofing material in a predetermined thickness (for example, 1 mm or more). A tensile jig having a predetermined adhesion area is attached to the test piece through the inner water-stopping material so that the inner water-stopping material adheres to the entire adhesion area. The tensile jig is pulled perpendicular to the test piece so as to pull the tensile jig away from the test piece. During tensioning, the tensile force acting between the test piece and the tensioning jig is measured using a known measuring device. "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 ).

In addition, the inner water stop 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 steel shell and concrete” can mean relative displacement between steel shell 6 and concrete 60 . In addition, "followability" can mean that the inner surface water-stop material can be deformed by the above-described relative displacement without breaking. Specifically, the inner water stop material 81 has a breaking elongation of 400% or more as followability. Since the inner surface water-stopping material 81 has such followability, high water-stopping performance can be obtained. In the present disclosure, "breaking elongation" (%) means permanent elongation after breaking when a general tensile test is performed using a test piece (for example, a dumbbell-shaped test piece) made from a water stop material. (Lu-L0) expressed as a percentage of the original gauge length L0. L0 is the gauge length marked on the specimen measured before testing and Lu is the gauge length marked on the specimen measured after breakage.

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

The inner surface water-stopping material 81 having adhesion, followability, and water-stopping properties as described above can be made of various materials. For example, the inner water stop material 81 can be made of epoxy resin, polyurethane resin, fluorine resin, acrylic rubber resin, polybutadiene rubber resin, chloroprene rubber resin, chlorosulfonated polyethylene resin, resin mortar, fiber-reinforced mortar, and non- vulcanized butyl rubber, and composite materials from some of these materials (e.g., materials formed by laminating layers of several of the above materials). can. In addition, the inner surface water stop material 81 can have the property of adhering to the ready-mixed concrete as the hydration reaction of the ready-mixed concrete progresses when the concrete 60 is placed. The inner surface water stop material 81 can be of a stickable or paintable type, for example. It should be noted that the outer peripheral water stop material 82 may be made of the same material as the inner surface water stop material 81 as described above.

Also, FIG. 12 is a schematic diagram showing a composite segment provided with a fixing member and an anti-slip device. The synthetic segment 1 can comprise a fastener 65 and a shear stop 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 separation between the steel shell 6 and the concrete 60 . In the present disclosure, “stripping” can mean that the steel shell 6 and the concrete 60 are separated from each other, creating a gap 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 anchor 65 can take on various shapes that can prevent the concrete 60 from leaving the steel shell 6, such as a T-shape, for example. The fixing member 65 can be made of various materials such as metal.

A slip stop 66 is provided on the inner surface of the steel shell 6 and is configured to prevent slippage between the steel shell 6 and the concrete 60 . In this disclosure, "slipping" can mean that the steel shell 6 and concrete 60 slide against each other (along at least one of the Y and Z directions) along the interface therebetween. The anti-slip 66 may be, for example, relatively large irregularities as shown in FIG. FIG. 12 shows only the anti-slip 66 for preventing displacement in the Z direction, but an anti-slip (not shown) is provided for preventing displacement in the Y direction along the direction perpendicular to the paper surface. good too. Also, in other embodiments, the anti-slip 66 may be asperities such as those obtained by roughening such as blasting.

Next, a method for manufacturing the synthetic segment 1 as described above will be described.

(a) to (e) of FIG. 13 are schematic diagrams showing a method for producing a synthetic segment. In this embodiment, a composite segment 1 having a steel shell 6 only on the main girder surface 3 as shown in FIG. 4 will be described. The steel shell 6 therefore has only the main girder steel plates 31 , 32 .

FIG. 13(a) shows the inner surfaces of the main girder steel plates 31 and 32. FIG. In this manufacturing method, first, at least one (two in this embodiment) inner surface water stop material 81 is arranged on the inner surfaces of the main girder steel plates 31 and 32 . Specifically, the inner surface water-stopping material 81 is attached inside the inner surface water-stopping groove 101 . To more reliably prevent the formation of a passage through which liquid can pass between main girder steel plates 31, 32 and concrete 60 by sticking an inner water stop material 81 in an inner water stop groove 101.例文帳に追加can be done. In addition, the inner water stop material 81 is sufficiently extended to the ends of the main girder steel plates 31 and 32 on the joint surface side (the left and right ends in FIG. 13(a)) so as to be connected to the outer peripheral water stop material 82 described later. be pasted on.

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. Referring to FIG. 13(b), in the present manufacturing method, next, main girder steel plates 31 and 32 are installed on the upper surface 22 of the placing formwork 20 so as to face each other. Note that FIG. 13(b) shows only one of the main girder steel plates 31 (the same applies to FIGS. 13(c) and 13(d)). Specifically, in this embodiment, the upper surface 22 of the casting form 20 is configured to contact the inner hollow side surface of the composite segment 1, and therefore the upper surface 22 has a convex arc surface shape. is presenting. As a result, during the manufacture of the composite segment 1, the casting formwork 20 is arranged so that the composite segment 1 is held upwardly convex (in an inverted boat shape) and the four corners of the composite segment 1 are aligned horizontally. Synthetic segment 1 can be supported (so-called prone strike). In addition, as described above, in the present embodiment, the steel shell 6 has only the main girder steel plates 31 and 32, so an auxiliary mold is placed on the top surface 22 of the placing formwork 20 to define a space to be filled with the concrete 60. The frames 21, 21 are arranged so as to face each other. Each auxiliary formwork 21 is arranged to connect the corresponding ends of the main girder steel plates 31 and 32 . For example, in an embodiment in which the steel shells 6 (corner steel plates 5) are arranged only at the four corners of the composite segment 1 as shown in FIG. In addition, an auxiliary formwork 21 can be arranged on each main girder surface 3 and each joint surface 4 . Further, for example, in an 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. 21 is unnecessary. Thus, those skilled in the art can understand that the necessary auxiliary formwork 21 can be arranged according to the form of the steel shell 6 .

Next, with reference to FIG. 13(c), reinforcing bars 64 and connecting members 61 are installed inside the steel shell 6 (main girder steel plates 31, 32). The connecting members 61 may be fixed to the main girder steel plates 31 and 32 by known fixing means such as welding, for example. The reinforcing bar 64 may be placed through an opening 63 provided in the connecting member 61, for example, as shown in FIG. 6(d). Referring to FIG. 13( c ), subsequently, the main girder steel plates 31 , 32 and the auxiliary formwork 21 , 21 cover the space surrounded by the main girder steel plates 31 , 32 and the auxiliary formwork 21 , 21 from above with the curing material 23 . It is arranged on the upper ends of the molds 21 , 21 . When the skin plate 9 is used, the skin plate 9 may be arranged instead of the curing material 23 .

Referring to FIG. 13(d), next, ready-mixed concrete is inserted from an opening 24 provided in the central part of the curing material 23, and the placing formwork 20, the main girder steel plates 31 and 32, the auxiliary formwork 21, The space defined by 21 and curing material 23 is filled with ready-mixed concrete. Concrete 60 is placed by this. After curing of the concrete 60 is completed, the composite segment 1 is removed from the mold. It is also possible to fill ready-mixed concrete without using the curing material 23 .

FIG. 13(e) shows the outer surfaces of the main girder steel plates 31 and 32. FIG. Subsequently, at least one (two in this embodiment) outer peripheral water stop material 82 is arranged on the outer surface of the main girder steel plates 31 and 32 . Specifically, the outer peripheral water stop material 82 is stuck in the outer peripheral water stop groove 100 . More specifically, as described above, in this embodiment, the composite segment 1 has the steel shell 6 only on the main girder surface 3, so the joint surface 4 is made of concrete 60 (see, for example, FIG. 4). ). Therefore, the auxiliary molds 21, 21 are provided with projections corresponding to the outer peripheral water stop grooves 100, and the joint surfaces 4 are provided with the outer peripheral water stop grooves 100 in the concrete 60. formed by Further, the end faces of the main girder steel plates 31 and 32 are also pre-formed with similar outer peripheral water stop grooves 100 (not shown). Then, the outer peripheral water stop material 82 is arranged in the outer peripheral water stop groove 100 . As described above, since the inner surface water-stopping material 81 is sufficiently attached to the ends of the main girder steel plates 31 and 32 on the joint surface side, the outer peripheral water-stopping material 82 is joined to the inner surface water-stopping material 81. . Synthetic segment 1 is manufactured by the above steps.

Those skilled in the art will appreciate that the method for producing Synthetic Segment 1 does not have to be performed in the above order, and can be performed in other orders as long as there is no technical conflict. For example, the step of arranging the inner water stop material 81 on the inner surface of the steel shell 6 (Fig. 13(a)), the step of installing the steel shell 6 in the casting form 20 (Fig. 13(b)), 6 (FIG. 13(c)) need not be performed in this order, and may be performed in a different order.

Also, in the above-described embodiment, the synthetic segment 1 is manufactured by hitting face down. In the case of face down, since the inner hollow side surface of the concrete 60 contacts the upper surface 22 of the placing formwork 20, it is possible to form a smooth inner hollow side surface of the concrete 60 that is visible from the inside of the tunnel. can. However, the composite segment 1 may also be produced by other casting methods.

For example, synthetic segment 1 may be manufactured by boat casting. In this case, the upper surface 22 of the casting form 20 is configured to contact the ground side surface of the synthetic segment 1, contrary to the boat-shaped casting described above, so that the upper surface 22 is a concave arcuate surface. shape. As a result, during the manufacture of the composite segment 1, the casting formwork 20 is configured so that the composite segment 1 is held downwardly convex (in a boat shape) and the four corners of the composite segment 1 are aligned horizontally. Support segment 1. Other aspects can be similar to prone strikes.

Also, for example, the composite segment 1 may be placed obliquely. In this case, the auxiliary formwork is installed with one joint surface 4 facing upward and the other joint surface 4 obliquely downward. The surface of the hollow side is arranged so as to be obliquely upward, the casting formwork is installed on this surface as well, and the casting formwork 20 is installed so that the surface of the natural ground side is obliquely downward, It can be placed in the same manner as above. Concrete can then be placed from the upper joint surface 4 or its vicinity. In this case, concrete can be placed without any problem by placing fluid concrete or the like. Other aspects can be similar to prone strikes.

Also, for example, the synthetic segment 1 may be manufactured by centrifugal stamping. in this case,
The casting mold 20 has, for example, a ring shape. The casting formwork 20 supports a plurality of composite segments 1 arranged in a ring on its inner peripheral surface, and is configured to come into contact with the surface of the plurality of composite segments 1 on the ground side. In centrifugal placing, after placing the inner surface water stop material 81 on the inner surface of the steel shell 6 , the steel shells 6 of a plurality of synthetic segments 1 are placed in a ring shape on the inner peripheral surface of the placing mold 20 . In addition, depending on the form of the steel shell 6, necessary auxiliary forms 21 are arranged. At this time, reinforcing bars 64 and connecting members 61 may be installed on the steel shell 6 inside the steel shell 6 as necessary. Subsequently, the placing formwork 20 is rotated around the center axis of the ring-shaped placing formwork 20, and the inner peripheral surface of the placing formwork 20 is moved from a predetermined position inside the placing formwork 20. Release ready-mixed concrete towards a predetermined location. The inside of each steel shell 6 is filled with ready-mixed concrete by centrifugal force due to the rotation, and concrete 60 is placed inside each steel shell 6 . After the curing of the concrete 60 is completed, the rotation of the placing formwork 20 is stopped and each composite segment 1 is demoulded. After that, the outer peripheral water stop material 82 is stuck in the outer peripheral water stop groove 100 on the outer peripheral surface of the steel shell 6 . In the case of such centrifugal placing, the ground side surface of the concrete 60 contacts the inner peripheral surface of the placing formwork 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 employed in constructing a shield tunnel,
・It can be applied to deep tunnels with high groundwater pressure,
・It can be applied to deep tunnels with large loads and cross-sectional forces, large cross-section tunnels, and non-circular cross-section tunnels.
・Because high water stopping performance can be expected for a long period of time, the service life of tunnels can be extended.
・By increasing the binding force between the steel shell and concrete, cracking of concrete during an earthquake or cracking due to internal water pressure acting on tunnels such as underground rivers is prevented.
Such effects can be expected, and the manufacturing cost of the synthetic segment can be reduced, so a great effect can be expected in reducing the initial cost and maintenance cost for infrastructure development.

1: Synthetic segment 20: Casting formwork 21: Auxiliary formwork 22: Upper surface of casting formwork 23: Curing material 24: Curing material opening 3: Main girder surface 31: One end side main girder steel plate 32: Other end side Main girder steel plate 4: Joint surface 41: One end side joint steel plate 42: Other end side joint steel plate 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 : Anti-slip 7 : Tunnel 70 : Segment ring 8 : Water stopping material 81 : Internal water stopping material 82 : Peripheral water stopping material 9 : Skin plate 100 : Outer water stop groove 101 : Inner water stop groove

Claims (14)

A synthetic segment for a tunnel comprising concrete, a steel shell and a water stop material,
The steel shell has at least both main girder surfaces of the synthetic segment on an outer peripheral surface composed of a main girder surface that is an axial end surface of the tunnel of the synthetic segment and a joint surface that is an end surface of the tunnel in the circumferential direction. Extending in the circumferential direction of the tunnel cross section and the normal direction of the tunnel cross section in
At least one outer peripheral water stop groove is provided on the main girder surface and the joint surface of the composite segment, an outer peripheral water stop material is arranged in the outer peripheral water stop groove, and at least one inner surface is provided on the inner surface side of the steel shell with respect to the concrete. Water stop material is arranged,
The synthetic segment, wherein the inner water stop material has adhesion to the steel shell and the concrete, and conformability to deformation at an interface between the steel shell and the concrete. The inner water stop material is
As the adhesiveness, it has an adhesive force of 1.5 MPa or more to the steel shell and the concrete,
As the followability, it has a breaking elongation of 400% or more,
A synthetic segment according to claim 1 . The inner surface waterproofing material includes epoxy resin, polyurethane resin, fluorine resin, acrylic rubber resin, polybutadiene rubber resin, chloroprene rubber resin, chlorosulfonated polyethylene resin, resin mortar, fiber-reinforced mortar, and non-vulcanized 3. A synthetic segment according to claim 1 or 2, comprising at least one of butyl rubber and composites of some of these materials. 4. The synthetic segment according to any one of claims 1 to 3, wherein the inner surface of the steel shell is provided with a fixing material for preventing separation between the steel shell and the concrete. 5. A composite segment according to any one of the preceding claims, wherein the inner surface of the steel shell is provided with a slip stop to prevent slippage between the steel shell and the concrete. 6. A synthetic segment according to any one of the preceding claims, wherein said steel shell is arranged only on part of said outer peripheral surface constituted by said main girder surface and said joint surface. The synthetic segment according to any one of claims 1 to 6, wherein the cracking strength of the concrete, the elastic reaction force of the inner water stop material, and the water pressure acting from the outside of the tunnel satisfy the following relational expressions: .
(Concrete cracking strength) > (Inner water stop material elastic reaction force) > (Water pressure acting on the tunnel) 8. The composite segment according to any one of claims 1 to 7, wherein the inner water-stopping material is arranged in an inner water-stopping groove provided on the inner surface of the steel shell. 9. The synthetic segment according to any one of claims 1 to 8, wherein the end portion of the inner surface water-stopping material and the outer peripheral water-stopping material are arranged in contact with each other. 10. A steel shell is arranged on both main girder surfaces of said composite segment, and a connecting member for connecting said steel shells and a reinforcing bar are arranged in contact with said connecting member. A synthetic segment as described in section. 11. The composite segment according to claim 10, wherein the connecting member is provided in contact with both the ground side and the hollow side of the reinforcing bar. 12. The synthetic segment according to any one of claims 1 to 11, wherein at least part of said water-stopping material is a water-swellable water-stopping material. 13. The synthetic segment according to any one of claims 1 to 12, wherein the outer peripheral 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. At least one of the main girder surface and the joint surface of the composite segment is the steel shell provided with a corrugated surface having uneven portions, and the concave portions of the corrugated surface are outer water stop grooves or inner surfaces. 14. The synthetic segment according to any one of claims 1 to 13, which is a water stop groove.

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