JP2007009556A - Segment for shield tunnel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a segment for a shield tunnel having high toughness, and restraining form production cost; and its manufacturing method. <P>SOLUTION: This segment 1 for the shield tunnel having integrally an ECC mortar layer 12 on a segment joint surface and a ring joint surface abutting on an adjacent segment, is manufactured by being integrated with a thin plate, by placing concrete in a part being an intermediate part of the segment arranged on the four periphery and surrounded by its thin plate and a segment manufacturing form, by arranging the precast thin plate composed of ECC mortar forming an outside surface shape (a water cut-off rubber arranging groove 12a, and a tenon groove projection 12b) of the segment joint surface or an outside surface shape (a water cut-off rubber arranging groove 12c, a guide pin 12d, and a concrete guide 12e) of the ring joint surface on a surface, on an inside side surface of the four periphery of the segment manufacturing form. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an arc plate-shaped shield tunnel segment obtained by dividing a cylindrical shell into a large number, and a method of manufacturing the same.

  Conventionally, in tunnels such as roads and railways, as a tunnel lining, a technique has been adopted in which a support is built inside the excavation tunnel and the lining is wound up with cast-in-place concrete. Technology to do has come to be adopted. Such a technique is to divide the tunnel into a large number in the axial direction, cut the ring, and further produce a circular cast plate-shaped shield tunnel precast segment divided into a large number in the circumferential direction. It is a technology for assembling on the inner surface, securing a circular cross section in the ground, and filling the backfill concrete between the outside of the assembled segment and the excavated ground, and excavating the tunnel forward. Such a technique has many advantages such as not requiring support work and enabling full-section excavation by an automated excavating machine, and is a general technique. Taking advantage of this technology, this technology has also been adopted for construction of tunnels such as water and sewage systems in urban areas, subways and underpasses, joint ditch tunnels such as electricity, gas and water, or composite tunnels thereof.

  When manufacturing such shield tunnel segments, we prepare molds for placing individual arc plate segment concrete for the number of segments of one divided round, and put concrete in these dedicated molds. Is manufactured. A tunnel formed by assembling such a segment needs not only to secure a cylindrical space but also to withstand an external force acting on the tunnel, for example, a bending moment due to earth pressure, water pressure, and uneven settlement. Further, depending on the application, it is required to resist the internal pressure.

  Conventionally, it is known that concrete has a characteristic that it is strong against compression but weak against tension. Therefore, as a segment for shield tunnel, a reinforced concrete segment that is reinforced by mechanically reinforcing the tensile force, which is a weak point of concrete, or by prestressing concrete by tensioning an embedded PC steel material Prestressed concrete segments with increased bending strength are used. In addition, for the purpose of improving the toughness of concrete, fiber reinforcement in which concrete fibers are mixed with inorganic fibers such as steel fibers and carbon fibers, or short and long fibers formed into synthetic resin fibers such as polyester fibers and aramid fibers. Concrete is also known.

For example, as a shield tunnel segment based on reinforced concrete, a general part made of a high-strength cementitious material, and a propulsion of a shield machine made of fiber-reinforced cementitious mixed material on the end face of this general part A segment having an end face member that is sometimes pressed by a propulsion jack has been proposed (see, for example, Patent Document 1).
JP 2005-76305 A

  According to the shield tunnel segment proposed in Patent Document 1, the portion hit by the shield jack when propelling the shield machine is reinforced with an end face member made of a fiber-reinforced cement-based mixed material that can improve toughness. Therefore, it has a proof strength against corner chipping, and the possibility of segment breakage is reduced even when it receives an eccentric load, for example. However, since the general part is made of a high-strength cementitious material, it is inferior in toughness compared to a fiber-reinforced cementitious mixed material.For example, when transporting a segment manufactured in a factory or an adjacent yard, If the corner portion of the general portion receives an impact accidentally, corner breakage may occur.

  In addition, from the standpoint of preventing corner chipping and breakage due to point contact between concrete after assembling the shield tunnel segment in the tunnel, it is necessary to make the joints between the segments highly precise mating surfaces. It is. As the dimensional accuracy, a surface accuracy of 1.0 mm or less, preferably 0.5 mm or less is required between the pieces (the circumferential seam of the segment) and between the rings (the tunnel axial direction seam of the segment). Since both the ring surface and the piece surface require a higher surface accuracy, a mold with high accuracy is required. As a result, the mold production costs are expensive.

  In view of the above circumstances, an object of the present invention is to provide a shield tunnel segment having high toughness and reduced formwork production costs, and a manufacturing method thereof.

  The shield tunnel segment of the present invention that achieves the above object is a segment of a circular arc plate-like shield tunnel obtained by dividing a cylindrical shell into a plurality of fine cracks on a segment joint surface and a ring joint surface that abuts adjacent segments. A type fiber reinforced cement composite material layer is provided integrally.

  Here, the “multiple fine cracked fiber reinforced cement composite material” referred to in the present invention is, for example, PVA (Polyvinyl Alcohol) fiber or PE (Polyethylene) having a fiber diameter φ = 10 μ to 40 μ and a fiber length l = 10 mm to 15 mm. This is one of cement-based composite materials in which fiber reinforcing materials such as fibers are mixed in cement mortar having a water cement ratio of 30% to 50% and a fine aggregate ratio of about 50%. Hereinafter, such “multiple fine cracked fiber reinforced cement composite material” is referred to as an ECC (Engineered Cementitious Composition) mortar. This ECC mortar shows strain hardening in which tensile stress increases after initial cracking under uniaxial tensile stress, and even after the initial cracking, multiple fine cracks of 0.1 mm or less are formed (multiple microcracking) It is a tough and ductile material with a maximum tensile strain of 4-5%. Moreover, this ECC mortar is a material having considerably higher shear rigidity and torsional rigidity than reinforced concrete. Since the design tensile yield strength of the ECC mortar directly affects the design shear strength of the reinforcing fiber, σy / γ (σy = 200 MPa to 250 MPa) may be calculated as it is as the allowable shear stress degree, and the large shear resistance I have power.

  The segment for shield tunnel of the present invention is provided with an ECC mortar layer having such characteristics and having a thickness of about 10 mm to 30 mm integrally on a segment joint surface and a ring joint surface in contact with an adjacent segment. The segment joint surface is formed with the outer shape of the segment joint surface, such as a water stop rubber installation groove or a tenon groove projection, and the ring joint surface has, for example, a water stop rubber installation groove, a guide pin, or a concrete guide. The outer surface shape of the ring joint surface is formed.

  Therefore, the segment for shield tunnel of the present invention has high toughness at the segment joint surface and ring joint surface. For example, when the segment is subjected to an eccentric load or the like, the segment manufactured in a factory or an adjacent yard is transported. Even when the corner portion receives an impact by mistake, the possibility of breakage such as corner chipping is reduced.

  In the shield tunnel segment of the present invention, the ECC mortar layer integrally provided on the segment joint surface and the ring joint surface shares the tensile load, and the tensile stress (circumferential tension) is applied to the ECC mortar layer. ) Acts as a multiple microcrack, preventing the occurrence of large cracks and reducing the possibility of damage due to cracks.

  Here, in the shield tunnel segment of the present invention, the segment may be a reinforced concrete structure, a multi-fine cracked fiber reinforced cement composite material structure, or a prestressed concrete structure.

  In the reinforced concrete segment, the ECC mortar layer integrally provided on the segment joint surface and the ring joint surface shares the tensile load with the disposed reinforcing bars, so that the amount of reinforcing bars can be reduced. it can.

  In addition, the above-mentioned ECC mortar segment is composed entirely of ECC mortar, so even if tensile stress (surface tension) acts on this segment, the cracks become multiple microcracks and designed on the tension side. Since the influence of the tensile yield strength can be reflected as it is, the amount of reinforcing bars can be reduced.

  Moreover, it is known that the water permeability of ECC mortar is about 1/10 compared with that of normal concrete. Due to the high moisture impermeability of such ECC mortars, segments with excellent durability are provided.

  The prestressed concrete segment is based on concrete or ECC mortar. According to the prestressed concrete segment using concrete as a base material, the amount of reinforcing bars can be reduced. Moreover, according to the segment of the prestressed concrete structure which uses ECC mortar as a base material, while being able to aim at reduction of the amount of reinforcing bars, the improvement of load bearing capacity can be aimed at.

  By reducing the amount of reinforcing bars in this way, the manufacturing cost of the segment is suppressed.

  Further, the manufacturing method of the shield tunnel segment of the present invention that achieves the above-described object provides the outer surface of the segment joint surface or the ring joint surface in manufacturing the arc plate-shaped shield tunnel segment obtained by dividing the cylindrical shell into a large number. A plate-like body to be formed is manufactured, a plurality of fine cracked fiber reinforced cement composite materials are placed in a thin plate form having the plate-like body as a bottom plate, and the segment joint surface or the ring is formed on the surface. Manufactures a precast thin plate made of multiple fine cracked fiber reinforced cement composites with the outer surface shape of the joint surface, and this precast thin plate is connected to the inner side surface of the four circumferences of the segment manufacturing formwork. Are placed in opposition to each other, and cemented hardened material is placed in the segment manufacturing formwork and integrated with the precast thin plate. And butterflies.

  The method for producing a shield tunnel segment of the present invention is produced by placing ECC mortar in a thin plate form having the plate-like body as a bottom plate, and the outer shape of the segment joint surface or ring joint surface on the surface. An intermediate portion of a segment, in which a precast thin plate made of ECC mortar formed with is disposed on the inner side surface of the four circumferences of the segment manufacturing formwork and surrounded by the thin plate arranged on the four circumferences and the segment manufacturing formwork A cement-type hardened material is placed on the part to be integrated with the thin plate. Therefore, according to the method for manufacturing a shield tunnel segment of the present invention, there is a precast thin plate that is integrated with the cast cementitious material to be cast and has a segment joint surface or a ring joint surface formed on the surface. Since the segment manufacturing formwork for cement-based hardened materials is also used, it is not necessary to cut the segment manufacturing formwork to form the outer shape of the segment joint surface or ring joint surface. It is sufficient that the formwork has a planar shape and has dimensional accuracy. Therefore, the production cost of the segment manufacturing formwork can be greatly reduced.

  Here, the manufacturing method of the segment for shield tunnel of the present invention includes a metal plate obtained by cutting the outer shape of the segment joint surface or the ring joint surface, and using the metal plate as a bottom plate. It is preferable to place a curing material in the frame, manufacture a curing material plate having a surface to which the outer surface shape is transferred, and use the curing material plate as the plate-like body.

  In general, a plate-like body formed by cutting a metal is expensive. Therefore, in this way, the hardened material plate manufactured by placing a hardened material such as cement-based hardened material, gypsum, thermosetting plastic, etc. in a plate-like formwork having the metal plate as a bottom plate. Can be manufactured at a low cost and in large quantities.

  In the method for manufacturing a shield tunnel segment according to the present invention described above, the cement-based hardened material is placed by placing reinforcing bars having both ends bonded to the precast thin plate in the segment manufacturing formwork and placing reinforced concrete. Providing a strut between the precast thin plates in the segment manufacturing formwork, and placing a plurality of fine cracked fiber reinforced cement composites with the struts embedded, or the segment It may be possible to embed a pre-tension type steel material in the manufacturing formwork or install a post-tension type PC steel material arrangement duct and place a cement-based hardened material.

  The thin plate made of the ECC mortar having the above-mentioned characteristics, which is integrated with the cement-based cured material of the segment manufactured by the method for manufacturing a shield tunnel segment of the present invention, will share the tensile load. . Therefore, when placing the reinforced concrete, the amount of reinforcing bars can be reduced. In addition, when the ECC mortar is placed with the struts embedded, the ECC mortar also shares the tensile load, so the amount of reinforcing bars can be reduced. In addition, when embedding the pre-tension type steel material or installing the post-tension type PC steel material placement duct and placing the cement-based hardened material, it is possible to reduce the amount of reinforcing bars and improve the load bearing capacity. it can. By reducing the amount of reinforcing bars in this way, the manufacturing cost of the segment is suppressed.

  According to the shield tunnel segment of the present invention, the toughness of the ECC mortar layer integrally provided on the segment joint surface and the ring joint surface in contact with the adjacent segment is high, so that the possibility of breakage such as corner chipping is reduced. Further, according to the shield tunnel segment of the present invention, the ECC mortar layer shares the tensile load, so the amount of reinforcing bars is reduced, and the tensile stress (surface tension) is applied to the ECC mortar layer. Even if it acts, the cracks become multiple microcracks, so that the generation of large cracks is prevented and the possibility of breakage due to cracks is reduced. Moreover, because of the high water impermeability of the ECC mortar, a segment having excellent durability is provided.

  Further, according to the method for manufacturing a shield tunnel segment of the present invention, there is a precast thin plate that is integrated with the cast cementitious material to be cast and on which the outer shape of the segment joint surface or the ring joint surface is formed. Since the segment manufacturing form for the cement-based curable material is also used, it is not necessary to process the segment manufacturing form, and the manufacturing cost of the segment manufacturing form can be greatly reduced.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an external perspective view of a shield tunnel segment to which an embodiment of the present invention is applied.

A segment 1 for a shield tunnel shown in FIG. 1 is an arc plate-like segment obtained by dividing a cylindrical shell into a large number, and is made of reinforced concrete 11 as a base material and has a thickness of about 10 mm to 30 mm (provided that the surface is formed on the surface). The ECC mortar layer 12 (not including the dimensions of the protruding portion and groove portion) is integrally provided on the segment joint surface and the ring joint surface in contact with the adjacent segment. This shield tunnel segment 1 is an embodiment of the shield tunnel segment of the present invention. Further, a water stop rubber installation groove 12 a and a tenon groove projection 12 b are formed on the segment joint surface in the circumferential direction of the segment of the surface of the ECC mortar layer 12. A water stop rubber installation groove 12c, a guide pin 12d, and a concrete guide 12e are formed on the ring joint surface in the tunnel axis direction. The water blocking rubber installation groove 12a and the tenon groove projection 12b are examples of the outer shape of the segment joint surface of the present invention. The water blocking rubber installation groove 12c, the guide pin 12d, and the concrete guide 12e are formed according to the present invention. The ECC mortar constituting the ECC mortar layer 12 is a PVA (Polyvinyl Alcohol) fiber or PE (Polyethylene) having a fiber diameter φ = 10 μ to 40 μ and a fiber length l = 10 mm to 15 mm. 1) A cement-based composite material in which fiber reinforcing materials such as fibers are mixed in 1% to 2% of cement mortar having a water cement ratio of 30% to 50% and a fine aggregate ratio of about 50%. It is an Example of a multiple fine crack type fiber reinforced cement composite material.

  This ECC mortar shows strain hardening in which tensile stress increases after initial cracking under uniaxial tensile stress, and even after the initial cracking, multiple fine cracks of 0.1 mm or less are formed (multiple microcracking) It is a tough and ductile material with a maximum tensile strain of 4-5%.

  Moreover, this ECC mortar is a material whose shear rigidity and torsional rigidity are considerably higher than those of reinforced concrete. Since the design tensile yield strength of the ECC mortar directly affects the design shear strength of the reinforcing fiber, σy / γ (σy = 200 MPa to 250 MPa) may be calculated as it is as the allowable shear stress degree, and the large shear resistance I have power.

  The shield tunnel segment 1 of the present embodiment is provided with the ECC mortar layer 12 having such characteristics integrally on a segment joint surface and a ring joint surface that come into contact with an adjacent segment. Therefore, the segment 1 for shield tunnel of this embodiment has high toughness at the segment joint surface and the ring joint surface. For example, when the segment 1 is subjected to an eccentric load or the like, Even when the corner portion is accidentally impacted when the segment 1 is transported, the possibility of breakage such as corner chipping is reduced. In the shield tunnel segment 1 of the present embodiment, the ECC mortar layer 12 integrally provided on the segment joint surface and the ring joint surface shares the tensile load, and the tensile stress (peripheral surface) is applied to the ECC mortar layer. Even if the tension is applied, the cracks become multiple microcracks, so that the generation of large cracks is prevented and the possibility of breakage due to cracks is reduced.

  Further, in the reinforced concrete segment 1, the ECC mortar layer 12 integrally provided on the segment joint surface and the ring joint surface shares the tensile load together with the disposed reinforcing bars 50 (see FIG. 9). The amount can be reduced, and the manufacturing cost of the segment 1 is suppressed.

  Next, a method for manufacturing the shield tunnel segment 1 shown in FIG. 1 will be described.

  First, the cutting which should form the outer surface shape of the water stop rubber installation groove 12a and the tenon groove protrusion 12b shown in FIG. 1 or the water stop rubber installation groove 12c, the guide pin 12d, and the concrete guide 12e shown in FIG. Processing is performed to manufacture plate-like bodies 20 and 21 as shown in FIGS. 2 and 3 (plate-like body manufacturing process). The plate-like bodies 20 and 21 are examples of the plate-like body of the present invention.

  2 and 3 are external perspective views showing an example of a plate-like body.

  In FIG. 2, a convex portion 20a for forming the outer surface shape of the water blocking rubber installation groove 12a shown in FIG. 1 and a concave portion 20b for forming the outer surface shape of the tenon groove projection 12b are shown in FIG. A plate-like body 20 formed by cutting is shown.

  Further, FIG. 3 shows a convex portion 21a for forming the outer surface shape of the water blocking rubber installation groove 12c shown in FIG. 1 and a concave portion 21b for forming the outer surface shape of the guide pin 12d with respect to a metal flat plate. And the plate-like body 21 in which the recessed part 21c for forming the outer surface shape of the concrete guide 12e was formed by cutting is shown.

  In this embodiment, although the example which performs the cutting etc. which should form the outer surface shape of a segment joint surface or a ring joint surface with respect to a metal flat plate was given, the example which manufactures the plate-shaped bodies 20 and 21 was given. The plate-like body is not limited to this, and a metal plate obtained by cutting the outer shape of the segment joint surface or the ring joint surface is manufactured, and the plate-like body is used as a bottom plate, for example, cement. A hardener such as a system hardener, gypsum, and thermosetting plastic may be placed to manufacture a hardener plate having a surface to which the outer shape is transferred, and this hardener plate may be used as a plate-like body. In general, a plate-like body formed by cutting a metal is expensive. However, by using such a hardened material plate as a plate-like body, it is possible to produce a plate-like body at a low cost and in large quantities.

  Next, as shown in FIGS. 4 and 5, side plates are erected on the four circumferences of the plate bodies 20 and 21 manufactured in the plate body manufacturing process, and the plate bodies 20 and 21 are used as bottom plates. The molds 30 and 32 are manufactured (the thin plate mold manufacturing process). The thin plate molds 30 and 32 are examples of the thin plate molds of the present invention.

  4 and 5 are external perspective views showing an example of a thin plate formwork.

  FIG. 4 shows a thin plate mold 30 that is manufactured by standing side plates 31 on the four circumferences of the plate-like body 20 shown in FIG. 2 and has the plate-like body 20 as a bottom plate.

  Further, FIG. 5 shows a thin plate formwork 32 having the plate-like body 21 as a bottom plate, which is manufactured by standing side plates 33 on the four circumferences of the plate-like body 21 shown in FIG.

  Next, in the thin plate molds 30 and 32 manufactured in the thin plate mold manufacturing process, a kneaded piece of ECC mortar is placed and cured, and the thin plate molds 30 and 32 are removed. 6, a thin plate 121 made of ECC mortar having a water stop rubber installation groove 12a and a tenon groove projection 12b formed on the surface as shown in FIG. 6, and a water stop rubber installation groove 12c on the surface as shown in FIG. A thin plate 124 made of ECC mortar in which the guide pins 12d and the concrete guide 12e are formed is manufactured (thin plate manufacturing process). The thin plates 121 and 124 are examples of the precast thin plate of the present invention. In curing the ECC mortar placed in the thin plate molds 30 and 32, an uneven shape is formed on the back surface of the ECC mortar before the placed ECC mortar is completely cured. Is preferred.

  6 and 7 are external perspective views showing an example of a thin plate.

  FIG. 6 shows the surface of the thin plate mold 30 shown in FIG. 4 which is manufactured by placing and curing a kneaded ECC mortar and removing the thin plate mold 30. A thin plate 121 made of ECC mortar in which water rubber installation grooves 12a and tenon groove projections 12b are formed is shown. Concavities and convexities are formed on the back surface 12f of the thin plate 121 with respect to the surface on which the water blocking rubber installation groove 12a and the tenon groove projection 12b are formed. Further, a coupler or reinforcing bar connector 13 (see FIG. 9) and a dowel 14 (see FIG. 9) are provided on the back surface 12f.

  FIG. 7 shows a surface produced by placing and curing a kneaded ECC mortar in the thin plate mold 32 shown in FIG. 5 and removing the thin plate mold 32. 3 shows a thin plate 124 made of ECC mortar in which a water blocking rubber installation groove 12c, a guide pin 12d, and a concrete guide 12e are formed. Concavities and convexities are formed on the back surface 12f of the thin plate 124 with respect to the surface on which the water blocking rubber installation groove 12c, the guide pin 12d, and the concrete guide 12e are formed. Further, a coupler or reinforcing bar connector 13 (see FIG. 9) and a dowel 14 (see FIG. 9) are provided on the back surface 12f.

  Next, the thin plates 121 and 122 made of ECC mortar, which are manufactured in the thin plate manufacturing process and formed with the water stop rubber installation groove 12a and the tenon groove protrusion 12b on the surface, the water stop rubber installation groove 12c and the guide pin 12d on the surface. And thin plates 123 and 124 made of ECC mortar on which the concrete guide 12e is formed are arranged on the inner side surface of the four circumferences of the segment manufacturing form 40 as shown in FIGS. , 123, 124 are arranged to face each other (thin plate arranging step).

  FIG. 8 is an external perspective view of the segment manufacturing formwork, and FIG. 9 is a plan view showing a state in which four thin plates are arranged on the segment manufacturing formwork shown in FIG.

  As shown in FIG. 8, the segment manufacturing formwork 40 forming the arc-shaped plate-like segment is placed in a flat plate shape on the floor with the arc projecting upward. A segment manufacturing form 40 shown in FIG. 8 is an embodiment of the segment manufacturing form of the present invention, and includes an arcuate side frame 41, a rectangular frame 42, and a curved plate-like bottom plate 43.

  Further, as shown in FIG. 9, on the inner side surface of the side frame 41, the inner side surface and a water stop rubber installation groove 12c, a guide pin 12d, and a concrete guide 12e are formed on the surface, which are manufactured in the thin plate manufacturing process. Further, the thin plates 123 and 124 made of ECC mortar are arranged to face each other via the thin plate spacer 16. Further, on the inner side surface of the end frame 42, the inner side surface and the surfaces of the thin plates 121 and 122 made of ECC mortar manufactured in the thin plate manufacturing process and having the water stop rubber installation groove 12a and the tenon groove projection 12b formed on the surface. Are arranged via a thin plate spacer 16. Further, on the back surface 12f with respect to the front surfaces of the thin plates 121, 122, 123, 124, a coupler or a reinforcing bar connector 13 for connecting the reinforcing bars 50 is provided, and between the opposing thin plates 121, 122, 123, 124, The reinforcing bar 50 is disposed integrally with the thin plates 121, 122, 123, 124 via the coupler or reinforcing bar connector 13 and the reinforcing bar spacer 51. Further, the back surface 12f with respect to the front surfaces of the thin plates 121, 122, 123, 124 is made of 2φ-3φ wire for improving the adhesion between the thin plates 121, 122, 123, 124 and the concrete to be placed. An annular dowel 14 is provided.

  Next, in the segment manufacturing formwork, concrete, which is an example of the cement-based hardened material of the present invention, was placed and cured, and placed on the inner side surface of the four circumferences of the segment manufacturing formwork in the thin plate placement process. Integrate with thin plate (cement-based hardened material placement process).

  10-12 is explanatory drawing which shows a cement-type hardening material placement process.

  As shown in FIG. 10, the concrete 60 is placed in the segment manufacturing form 40 while applying the upper lid 44, and the concrete placement is continued while sequentially covering the upper surface with the upper lid 44 as shown in FIG. 11.

  Here, as shown in FIG. 6 and FIG. 7, the back surface 12f with respect to the surface of the thin plates 121, 122, 123, and 124 is formed with irregularities, and further, as shown in FIG. 14 is provided, the thin plates 121, 122, 123, and 124 and the placed concrete 60 are strongly bonded and integrated.

  Next, as shown in FIG. 12, the upper lid 44 is removed, and the surface 60a of the concrete in the segment manufacturing formwork 40 is smoothed. After the concrete 60 is cured, the segment manufacturing form 40 is removed from the mold, and as shown in FIG. 1, the ECC joint mortar layer 12 composed of the thin plates 121, 122, 123, and 124 is brought into contact with the adjacent segments and the ring. The segment 1 for every sheet which uses the reinforced concrete 11 as a base material integrally provided in the joint surface is obtained.

  As described above, the shield tunnel segment manufacturing method of the present embodiment is manufactured by placing ECC mortar in the thin plate molds 30 and 32 having the plate-like bodies 20 and 21 as bottom plates. Precast thin plates 121, 122, 123, 124 made of ECC mortar with the outer surface shape of the segment joint surface or ring joint surface formed on the surface are arranged on the four inner sides of the segment manufacturing formwork 40, Concrete 60 is placed in the middle part of the segment surrounded by the thin plates 121, 122, 123, 124 and the segment manufacturing form 40, and the thin plates 121, 122, 123, 124 are To be integrated. Therefore, according to the shield tunnel segment manufacturing method of the present embodiment, the thin plates 121, 122, 123 that are integrated with the cast concrete 60 and that have the outer surface shape of the segment joint surface or the ring joint surface formed on the surface. , 124 also serves as a formwork for the concrete 60, and therefore it is not necessary to perform cutting or the like on the segment manufacturing formwork 40 to form the outer shape of the segment joint surface or the ring joint surface. The manufacturing form 40 is sufficient if it has a planar shape and dimensional accuracy. Therefore, the manufacturing cost of the segment manufacturing form 40 can be significantly reduced.

  Next, as another embodiment of the present invention, a method for manufacturing an ECC mortar shield tunnel segment and a method for manufacturing a prestressed concrete shield tunnel segment will be described.

  In the embodiment described below, since the manufacturing method is almost the same as the manufacturing method described in the above-described embodiment, the difference from the above-described embodiment is noted, and the same elements are denoted by the same reference numerals. Is omitted.

  First, a method for manufacturing an ECC mortar shield tunnel segment will be described.

  The thin plates 121 and 122 made of ECC mortar, which are manufactured in the thin plate manufacturing process and formed on the surface with the water stop rubber installation groove 12a and the tenon groove projection 12b, and the water stop rubber installation groove 12c, the guide pin 12d, and the concrete are formed on the surface. The thin plates 123 and 124 made of ECC mortar on which the guide 12e is formed are arranged on the inner side surface of the four circumferences of the segment manufacturing formwork 40 as shown in FIGS. 8 and 13, and the inner side surface and each of the thin plates 121, 122, 123, It arrange | positions facing the surface of 124 (thin board arrangement | positioning process).

  FIG. 13 is a plan view showing a state in which four thin plates are arranged in the segment manufacturing form shown in FIG.

  As shown in FIG. 13, the inner side surface of the side frame 41 is opposed to the inner side surface and the surfaces of the thin plates 123 and 124 made of the ECC mortar manufactured in the thin plate manufacturing process via the thin plate spacer 16. Arrange. In addition, the inner side surface of the wife frame 42 is disposed via the thin plate spacer 16 so that the inner side surface and the surfaces of the thin plates 121 and 122 made of ECC mortar manufactured in the thin plate manufacturing process face each other. Further, a coupler or a reinforcing bar connector 15 for connecting the strut 70 is provided on the back surface 12f with respect to the front surfaces of the thin plates 121, 122, 123, and 124, and the opposing thin plates 121, 122, 123, and 124 are mutually connected. In the meantime, the strut 70 is disposed via the coupler or the reinforcing bar connector 15, and the thin plates 121, 122, 123, 124 are positioned at predetermined positions (thin plate disposing step). Although not shown here, the back surface 12f is also provided with a coupler or a reinforcing bar connector for connecting the reinforcing bars, and the reinforcing bars are connected between the opposing thin plates 121, 122, 123, and 124. Or it arrange | positions integrally with the thin plates 121,122,123,124 through the reinforcing bar connector and the reinforcing bar spacer.

  Next, ECC mortar, which is an embodiment of the cement-based hardened material of the present invention, is placed and cured in a segment manufacturing form by embedding a strut 70, and the segment manufacturing form of the segment manufacturing form is performed in a thin plate disposing process. It is integrated with a thin plate disposed on the inner side surface of the four circumferences (cement-based hardening material placing step).

  Since the segment of the ECC mortar manufactured in this way is composed entirely of ECC mortar, even if tensile stress (surrounding surface tension) acts on this segment, the cracks become multiple microcracks, Since the influence of the design tensile yield strength can be directly reflected on the tension side, the amount of reinforcing bars is further reduced (about 1/2 to 1/3) as compared with the reinforced concrete segment 1 shown in FIG. be able to. Moreover, it is known that the water permeability of ECC mortar is about 1/10 compared with that of normal concrete. Due to the high moisture impermeability of such ECC mortars, segments with excellent durability are provided. By reducing the amount of reinforcing bars in this way, the manufacturing cost of the segment is suppressed.

  Next, a method for manufacturing a prestressed concrete shield tunnel segment will be described.

  The thin plates 121 and 122 made of ECC mortar, which are manufactured in the thin plate manufacturing process and formed on the surface with the water stop rubber installation groove 12a and the tenon groove projection 12b, and the water stop rubber installation groove 12c, the guide pin 12d, and the concrete are formed on the surface. The thin plates 123 and 124 made of ECC mortar on which the guide 12e is formed are arranged on the inner side surface of the four circumferences of the segment manufacturing mold 40 as shown in FIGS. 8 and 14, and the inner side surface and each of the thin plates 121, 122, 123, It arrange | positions facing the surface of 124 (thin board arrangement | positioning process).

  FIG. 14 is a plan view showing a state in which four thin plates are arranged on the segment manufacturing form shown in FIG.

  As shown in FIG. 14, the inner side surface of the side frame 41 is opposed to the inner side surface and the surfaces of the thin plates 123 and 124 made of the ECC mortar manufactured in the thin plate manufacturing process via the thin plate spacer 16. Arrange. In addition, the inner side surface of the wife frame 42 is disposed via the thin plate spacer 16 so that the inner side surface and the surfaces of the thin plates 121 and 122 made of ECC mortar manufactured in the thin plate manufacturing process face each other. Prestressed concrete may be pre-tensioned or post-tensioned. For example, a fixing body mold 80 having a PC steel material arrangement duct 81 attached to the back surface 12f with respect to the front surface of the thin plate 123 disposed inside the side frame 41 is provided. (Thin plate arranging step). This PC steel material arrangement duct 81 is an embodiment of the PC steel material arrangement duct of the present invention.

  Next, concrete or ECC mortar, which is an embodiment of the cement-based hardened material of the present invention, is placed and cured in the segment manufacturing formwork, and placed on the inner side of the four circumferences of the segment manufacturing formwork in the thin plate placement process. Integrate with the installed thin plate (cement-based hardening material placement process). After the cement-based cured material is cured, prestress is introduced into the cement-based cured material. In this embodiment, an example in which pre-stress is introduced by the post-tension method has been shown. However, after pre-tensioning the PC steel material and hardening the cement-based hardened material, the tension is released and pre-stress is applied to the cement-type hardened material. Prestress may be introduced by a pretension method that introduces stress.

  The prestressed concrete segment thus produced is based on concrete or ECC mortar. According to the prestressed concrete segment using concrete as a base material, the amount of reinforcing bars can be reduced. Moreover, according to the segment of the prestressed concrete structure which uses ECC mortar as a base material, while being able to aim at reduction of the amount of reinforcing bars, the improvement of load bearing capacity can be aimed at. By reducing the amount of reinforcing bars in this way, the manufacturing cost of the segment is suppressed.

  As described above, according to the shield tunnel segment and the manufacturing method thereof of the present embodiment, the amount of reinforcing bars and the formwork cost can be reduced, and a tunnel having excellent durability can be constructed. Further, the amount of reinforcing bars can be further reduced by applying prestress.

1 is an external perspective view of a shield tunnel segment to which an embodiment of the present invention is applied. It is an external appearance perspective view which shows an example of a plate-shaped object. It is an external appearance perspective view which shows an example of a plate-shaped object. It is an external appearance perspective view which shows an example of the mold for thin plates. It is an external appearance perspective view which shows an example of the mold for thin plates. It is an external appearance perspective view which shows an example of a thin plate. It is an external appearance perspective view which shows an example of a thin plate. It is an external appearance perspective view of a segment manufacturing formwork. It is a top view which shows the state by which four thin plates were arrange | positioned with respect to the segment manufacturing formwork shown in FIG. It is explanatory drawing which shows a cement-type hardening material placement process. It is explanatory drawing which shows a cement-type hardening material placement process. It is explanatory drawing which shows a cement-type hardening material placement process. It is a top view which shows the state by which four thin plates were arrange | positioned with respect to the segment manufacturing formwork shown in FIG. It is a top view which shows the state by which four thin plates were arrange | positioned with respect to the segment manufacturing formwork shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shield tunnel segment 11 Reinforced concrete 12 ECC mortar layer 12a Water stop rubber installation groove 12b Tenon groove protrusion 12c Water stop rubber installation groove 12d Guide pin 12e Concrete guide 12f Back surface 121, 122, 123, 124 Thin plate 13, 15 Coupler or rebar connection Tool 14 Giber 16 Thin plate spacer 20, 21 Plate-like body 20a, 21a Convex part 20b, 21b, 21c Concave part 30, 32 Thin plate form 31, 33 Side plate 40 Segment production form 41 Side frame 42 Wife frame 43 Bottom plate 44 Top cover 50 Reinforcing Bars 51 Reinforcing Bar Spacers 60 Concrete 70 Struts 80 Fixing Forms 81 PC Steel Placement Duct

Claims (5)

  A circular arc shaped shield tunnel segment with a large number of cylindrical shells divided into a plurality of fine cracked fiber reinforced cement composite layers on the segment joint surface and ring joint surface that abuts adjacent segments. Characteristic shield tunnel segment.   2. The shield tunnel segment according to claim 1, wherein the segment is a reinforced concrete structure, a plurality of fine cracked fiber reinforced cement composite materials, or a prestressed concrete structure.   In manufacturing a circular arc plate-shaped shield tunnel segment obtained by dividing a cylindrical shell into a large number, a plate-like body to be formed on the outer surface shape of a segment joint surface or a ring joint surface is produced, and the plate-like body is used as a bottom plate. A plurality of fine cracked fiber reinforced cement composite material in which a plurality of fine cracked fiber reinforced cement composite materials are placed in a thin plate mold, and the outer surface shape of the segment joint surface or the ring joint surface is formed on the surface. The precast thin plate is manufactured, and the precast thin plate is disposed on the inner side of the four circumferences of the segment manufacturing form with the inner side and the surface facing each other, and cement-based hardening is provided in the segment manufacturing form. A method for producing a segment for a shield tunnel, wherein a material is cast and integrated with the precast thin plate.   A metal plate obtained by cutting the outer shape of the segment joint surface or the ring joint surface is manufactured, and a hardener is placed in a mold for a plate-like body using the metal plate as a bottom plate, and the outer surface shape is transferred. 4. A method for producing a shield tunnel segment according to claim 3, wherein a hardened material plate having a curved surface is produced and the hardened material plate is used as the plate-like body.   Placing the cement-based hardened material includes disposing reinforcing bars having both ends bonded to the precast thin plate in the segment manufacturing formwork, and placing reinforced concrete, and the precast thin plate in the segment manufacturing formwork. A strut material is applied between them, and a plurality of fine cracked fiber reinforced cement composite materials are placed by embedding the strut material, or a pretension type steel material is embedded in the segment manufacturing formwork, or 4. The method for producing a shield tunnel segment according to claim 3, wherein a post-tension type PC steel material arrangement duct is installed to cast a cement-based hardened material.

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