Method for constructing a concrete structure and method for cutting a concrete structure

Abstract

To provide a joint device with a simple structure capable of connecting an end of a reinforcing bar and an end of a rod-shaped member made of resin.SOLUTION: A joint device 1 connects an end portion 11 of a reinforcing bar 10 and an end portion 21 of a rod-shaped member 20 made of resin. The joint device 1 comprises a tubular member 2 in which the end portion 11 of the reinforcing bar 10 is inserted into a hollow portion 2a from an opening portion 2b on one end side, and the end portion 21 of the rod-shaped member 20 is inserted into the hollow portion 2a from an opening portion 2c on the other end side, and a grout material 3 filled into the hollow portion 2a of the tubular member 2 into which the end portion 11 of the reinforcing bar 10 and the end portion 21 of the rod-shaped member 20 has been inserted.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a joint device that connects an end of a reinforcing bar and an end of a rod-shaped member made of resin, a concrete structure in which this joint device, the reinforcing bar, and the rod-shaped member are embedded, and a method for cutting this concrete structure. [Background technology]

[0002] Patent Document 1 discloses a joint fitting that is applied to joining dissimilar materials when carbon fiber reinforced plastic (CFRP) is used as a so-called brace material. In Patent Document 1, a steel joint fitting for connection is embedded in the end of the CFRP material that corresponds to the joint with the dissimilar material to form an integrated unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-42233 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, there has hitherto not been any suitable mechanical joint (joint device) for connecting an end of a reinforcing bar and an end of a rod-shaped member made of resin.

[0005] In view of the above circumstances, the present invention has an object to provide a joint device of simple configuration capable of connecting an end of a reinforcing bar and an end of a rod-shaped member made of resin. [Means for solving the problem]

[0006] Therefore, the joint device according to the present invention is One end and a resin rod-shaped member lower end The joint device of the present invention connects the reinforcing bar. One end is down The rod-shaped member is inserted into the hollow portion from the opening at the end. Bottom end is up Inserted into the hollow space from the opening on the end Extends vertically Cylindrical member and reinforcing bar One end and rod-shaped member lower end and a grout material that is filled in the hollow portion of the tubular member into which the groove is inserted.

[0007] The method for constructing a concrete structure according to the present invention is a method for constructing a concrete structure in a space formed by excavating the ground. The method for constructing a concrete structure according to the present invention comprises the steps of: In a space formed by excavating the ground, one end of a reinforcing bar is connected to a lower end of a resin rod-shaped member extending vertically via a joint device; Constructing a wall of a concrete structure by pouring concrete so as to encase the other end of the reinforcing bar, the joint device, and the rod-shaped member while leaving the other end of the reinforcing bar exposed; Constructing a bottom portion of a concrete structure by pouring concrete so as to encase a portion of the other end of the reinforcing bar; Includes. Here, the joint device and the reinforcing bar are located lower than the top surface of the bottom of the concrete structure. The method for cutting a concrete structure according to the present invention comprises the steps of: Constructed by a method for constructing concrete structures Concrete Structure Wall Cutting the part where the rod-shaped member is embedded forming an opening in a wall of the concrete structure by forming a concrete structure wall having a lower edge adjacent to an upper surface of the bottom of the concrete structure. Effect of the Invention

[0008] According to the present invention, the joint device is composed of the above-mentioned tubular member and grout material, and therefore the joint device can have a simple structure. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a cross-sectional view of a joint device in one embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of a vertical shaft to which the joint device in the above embodiment is applied. [Diagram 3] FIG. 13 illustrates a method of cutting a shaft, including a method of constructing the shaft. [Figure 4] FIG. 13 illustrates a method of cutting a shaft, including a method of constructing the shaft. [Diagram 5] FIG. 13 illustrates a method of cutting a shaft, including a method of constructing the shaft. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] FIG. 1 shows a schematic configuration of a joint device according to one embodiment of the present invention.

[0012] The joint device 1 connects an end 11 of a reinforcing bar 10 and an end 21 of a bar-shaped member (rod) 20 made of resin (synthetic resin). The joint device 1 includes, for example, a cylindrical tubular member (sleeve) 2 and a grout material 3 filled in a hollow portion 2a of the tubular member 2.

[0013] The cylindrical member 2 is made of, for example, metal. In this embodiment, the cross-sectional shape of the cylindrical member 2 is circular, but the cross-sectional shape may also be polygonal.

[0014] An end 11 of the reinforcing bar 10 is inserted into the hollow portion 2a from an opening 2b on one end side of the tubular member 2. An end 21 of a rod-shaped member 20 is inserted into the hollow portion 2a from an opening 2c on the other end side of the tubular member 2.

[0015] The reinforcing bar 10 may be a round bar or a deformed bar (deformed steel bar). The reinforcing bar 10 may extend straight or may be bent or curved (see, for example, Figs. 4 and 5 described later).

[0016] The rod-shaped member 20 extends linearly. The rod-shaped member 20 is preferably made of fiber reinforced plastic (FRP), more preferably made of glass fiber reinforced plastic (GFRP) or carbon fiber reinforced plastic (CFRP), and particularly preferably made of carbon fiber reinforced plastic (CFRP). The rod-shaped member 20 may be a round bar, or may have a spiral convex portion (e.g., a male screw portion) formed on the outer circumferential surface of the round bar.

[0017] The rod-shaped member 20 has a Young's modulus (modulus of longitudinal elasticity) of 80000 N / mm 2 It is preferable that the resistance is 100,000 N / mm or more. 2 More preferably, it is equal to or greater than this.

[0018] An example of the rod-shaped member 20 used in this embodiment is made of carbon fiber reinforced plastic (CFRP), and its Young's modulus is 200000 N / mm 2 Therefore, the rod member 20 in this example is made of a highly elastic material (that is, a material that is less likely to be distorted (deformed) by tensile stress).

[0019] In this embodiment, the diameter (outer diameter) D2 of the rod-shaped member 20 is smaller than the diameter (outer diameter) D1 of the reinforcing bar 10, assuming that the reinforcing bar 10 has the same strength performance (for example, tensile strength) as the rod-shaped member 20. By adopting the rod-shaped member 20 having a small diameter (outer diameter) D2, the interval between the outer peripheral surface of the end 21 of the rod-shaped member 20 inserted into the hollow portion 2a of the tubular member 2 and the inner peripheral surface of the tubular member 2 can be increased, and the filling property of the grout material 3 between the tubular member 2 and the end 21 of the rod-shaped member 20 is improved. Therefore, the end 21 of the rod-shaped member 20 and the tubular member 2 can be reliably integrated by the grout material 3, and the performance as a joint structure is improved. In consideration of the allowable strength, etc., the cross-sectional area of ​​the rod-shaped member 20 is preferably within a range of 50 to 90% of the cross-sectional area of ​​the reinforcing bar 10.

[0020] An annular sealing member 4 is provided to close the gap between the inner peripheral surface of the opening 2b on one end side of the tubular member 2 and the outer peripheral surface of the end 11 of the reinforcing bar 10. The end 11 of the reinforcing bar 10 is inserted into the central through hole 4a of the sealing member 4.

[0021] An annular seal member 5 is provided to close the gap between the inner peripheral surface of the opening 2c on the other end side of the cylindrical member 2 and the outer peripheral surface of the end 21 of the rod-shaped member 20. The end 21 of the rod-shaped member 20 is inserted into a central through hole 5a of the seal member 5.

[0022] Here, the inner diameters of the through holes 4a, 5a of the sealing members 4, 5 can be appropriately selected so as to correspond to the mutually different diameter (outer diameter) D1 of the reinforcing bar 10 and the diameter (outer diameter) D2 of the rod-shaped member 20. Note that in this embodiment, the inner diameter (diameter of the hollow portion 2a) of the cylindrical member 2 is constant (the same size) in the longitudinal direction of the cylindrical member 2, but in addition, the inner diameter (diameter of the hollow portion 2a) of the cylindrical member 2 may be different in the longitudinal direction of the cylindrical member 2. For example, in the hollow portion 2a of the tubular member 2, a portion into which the end portion 11 of the reinforcing bar 10 is inserted is designated as hollow portion 2a1, and a portion into which the end portion 21 of the rod-shaped member 20 is inserted is designated as hollow portion 2a2. On the condition that the diameters (inner diameters) of the hollow portions 2a1 and 2a2 correspond to the diameter (outer diameter) D1 of the reinforcing bar 10 and the diameter (outer diameter) D2 of the rod-shaped member 20, and that the intervals required for injecting and filling the grout material 3 are secured, hollow part The diameter (inner diameter) of 2a2 is hollow part It may be smaller than the diameter (inner diameter) of 2a1.

[0023] Although not shown in the drawings, an injection hole for injecting grout material 3 into the hollow portion 2a and an exhaust hole are formed penetrating the cylindrical member 2 so as to communicate between the inside and the outside of the cylindrical member 2. For example, one of the injection hole and the exhaust hole is formed penetrating one end side of the cylindrical member 2, and the other is formed penetrating the other end side of the cylindrical member 2.

[0024] The grout material 3 is injected (filled) from the injection hole into the hollow portion 2a of the tubular member 2 into which the end portion 11 of the reinforcing bar 10 and the end portion 21 of the rod-shaped member 20 are inserted. The grout material 3 includes an expansive material.

[0025] In a first example of the grout material 3 including an expansive agent, the grout material 3 is, for example, in any one of a liquid state, a slurry state, and a gel state when it is filled into the hollow portion 2a, and expands after being filled into the hollow portion 2a. In the first example of the grout material 3, for example, a slurry-like grout material 3 can be produced by adding water to a cement-based powder material mainly composed of lime and silicate, and kneading the mixture.

[0026] In the first example of the grout material 3, the expansion pressure of the grout material 3 is 20 N / mm 2It is preferable that the expansion pressure of the grout material 3 is 30 N / mm 2 It is more preferable that the expansion pressure of the grout material 3 is 20 N / mm or more. Here, the expansion pressure of the grout material 3 is a pressure generated by the expansion of the grout material 3 after a sufficient time has elapsed (for example, 48 hours) since the grout material 3 was filled into the hollow portion 2a. 2 or more (more preferably 30N / mm 2 By adopting the above configuration, the joint device 1 can firmly connect the end 11 of the reinforcing bar 10 and the end 21 of the rod-shaped member 20 together.

[0027] In the second example of the grout material 3, the grout material 3 includes a non-shrink mortar. Here, the non-shrink mortar is, for example, mortar in which an appropriate amount of an expansive material is mixed into cement to reduce drying shrinkage. In other words, the grout material 3 also includes an expansive material in the second example of the grout material 3. In the second example of the grout material 3, the expansion pressure of the grout material 3 is not generated or is very low compared to the first example of the grout material 3 described above.

[0028] Next, a vertical shaft 30, which is an example of a concrete structure to which the joint device 1 is applied, will be described with reference to Fig. 2. Fig. 2 shows a schematic configuration of the vertical shaft 30.

[0029] The shaft 30 is made of concrete and has a bottomed cylindrical shape that extends vertically underground. The shaft 30 has a cylindrical wall 31 and a bottom 32. The internal space 33 of the shaft 30 is surrounded by the wall 31 and the bottom 32. The wall 31 is constructed of concrete reinforced with reinforcing bars, for example, by a reverse winding method. Here, the shaft 30 functions as a partition wall that separates the internal space 33 (underground space) from the surrounding ground. In this embodiment, the cross-sectional shape of the wall 31 is circular, but the cross-sectional shape may also be polygonal.

[0030] In this embodiment, a planned cutting area 34 is formed in the lower part of the wall body 31 and adjacent to the bottom part 32. This planned cutting area 34 is, for example, an area to be cut by a cutter head of a shield tunneling machine (not shown) when the shield tunneling machine starts from inside the vertical shaft 30 and constructs an adit (an area where so-called mirror cutting is performed).

[0031] In this embodiment, in the planned cutting area 34 of the wall body 31, a plurality of rod-shaped members 20 are embedded in concrete as concrete reinforcement instead of reinforcing bars. In other words, the planned cutting area 34 of the wall body 31 is a portion of the shaft 30 where a plurality of rod-shaped members 20 are embedded in concrete. For those of these rod-shaped members 20 that extend in the vertical direction, the above-mentioned joint device 1 is used to fix the lower end portions of the rod-shaped members 20 to the bottom 32 (in other words, to anchor them). Here, for example, the above-mentioned joint device 1 is used in the portion P in FIG. 2.

[0032] Figures 3 to 5 show a method of cutting the shaft 30, including a method of constructing the shaft 30. Here, Figures 3(a) to 5(e) show the method of constructing the shaft 30, and Figure 5(f) shows the starting shaft mouth 40 formed in the shaft 30 and the tunnel 60 (lining not shown) excavated in the ground. Figures 3(a) to 5(f) correspond to part P in Figure 2 described above.

[0033] When constructing the shaft 30, first, a ground improvement body 50 is constructed in the ground as shown in Fig. 3(A). This ground improvement body 50 is constructed so as to include at least a part of the planned construction area 35 of the ground for the shaft 30. In constructing the ground improvement body 50, a well-known freezing method or a high-pressure jet mixing method can be adopted.

[0034] Next, as shown in Fig. 3(a), the construction area 35 is excavated so as to include at least a part of the ground improvement body 50, thereby forming a construction space 36 in the ground. This construction space 36 can become the internal space 33. The construction space 36 is surrounded by, for example, a bottom excavation surface 37 and a side excavation surface 38. A wall body 31 and a bottom 32 are constructed in the construction space 36 (see Figs. 4(c) to 5(e) described later).

[0035] Next, as shown in Figure 4 (u), a reinforcing bar 10A connected via a joint device 1A is placed to the lower end of a rod-shaped member 20A extending in the vertical direction, and a reinforcing bar 10B connected via a joint device 1B is placed to the lower end of a rod-shaped member 20B extending in the vertical direction.

[0036] Here, joint devices 1A and 1B correspond to the joint device 1 shown in Fig. 1. Reinforcing bars 10A and 10B correspond to the reinforcing bar 10 shown in Fig. 1. Rod-shaped members 20A and 20B correspond to the rod-shaped member 20 shown in Fig. 1.

[0037] The rod-shaped member 20A is an outer concrete reinforcing bar that constitutes the planned cutting area 34 of the wall body 31 of the shaft 30. The rod-shaped member 20B is an inner concrete reinforcing bar that constitutes the planned cutting area 34 of the wall body 31 of the shaft 30.

[0038] Reinforcing bar 10A is bent at bent portion 10AD midway and extends in an L-shape. Straight portion 10AC extending vertically of reinforcing bar 10A extends along side excavation surface 38 with a predetermined distance therebetween. Straight portion 10AE extending horizontally of reinforcing bar 10A extends along bottom excavation surface 37 with a predetermined distance therebetween. At least a portion of straight portion 10AE of reinforcing bar 10A functions as an anchor portion that is embedded in concrete at bottom 32 of shaft 30.

[0039] Reinforcing bar 10B is bent at bent portion 10BD midway and extends in an L-shape. Straight portion 10BC extending vertically of reinforcing bar 10B extends substantially parallel to straight portion 10AC of reinforcing bar 10A with a predetermined gap therebetween. Straight portion 10BE extending horizontally of reinforcing bar 10B extends substantially parallel to straight portion 10AE of reinforcing bar 10A with a predetermined gap therebetween. At least a portion of straight portion 10BE of reinforcing bar 10B functions as an anchor portion that is embedded in concrete at bottom 32 of shaft 30.

[0040] Next, as shown in Fig. 4(d), concrete is poured so as to encase the joint devices 1A, 1B, the reinforcing bars 10A, 10B, and the rod-shaped members 20A, 20B, thereby forming a wall body 31 including an intended cutting region 34. In this process, a portion of the straight portion 10AE of the reinforcing bar 10A that functions as the aforementioned fixing portion (anchor fixing portion) and a portion of the straight portion 10BE of the reinforcing bar 10B that functions as the aforementioned fixing portion (anchor fixing portion) are left exposed.

[0041] Next, as shown in FIG. 5(o), bottom 32 is formed by pouring concrete so as to encase the portion of straight section 10AE of reinforcing bar 10A that functions as the aforementioned fixing portion (anchor fixing portion) and the portion of straight section 10BE of reinforcing bar 10B that functions as the aforementioned fixing portion (anchor fixing portion).

[0042] In this manner, the shaft 30 is constructed.

[0043] 5(F), for example, a cutter head of a shield tunneling machine starting from a vertical shaft 30 is used to cut a planned cutting area 34 of the wall body 31, thereby forming a starting tunnel entrance 40 (opening) in the wall body 31. Thereafter, the above-mentioned shield tunneling machine excavates the ground including the ground improvement body 50 to form a tunnel 60.

[0044] Here, the tunnel 60 is, for example, a shield tunnel formed by the shield tunneling method. In the shield tunneling method, although not shown in the figures, the shield tunneling machine excavates the ground while assembling segments one after another at the rear of the shield tunneling machine to form a cylindrical lining. In this method, the shield tunneling machine pushes the lining behind it backward with a thrust jack, and the thrust generated as a reaction force allows the shield tunneling machine to move forward while excavating the ground.

[0045] In this embodiment, the intended cutting area 34 of the wall 31 is cut with the cutter head of a shield tunneling machine to form an opening, but it is also possible to cut the intended cutting area 34 of the wall 31 to form an opening using an excavation machine other than a shield tunneling machine, such as a backhoe or an electric shovel (hydraulic excavator).

[0046] In this manner, the shaft 30 can be cut.

[0047] Incidentally, when the lower ends of the rod-shaped members 20A, 20B embedded in the planned cutting region 34 of the wall body 31 are fixed (anchored) to the bottom 32, if the lower ends are extended and bent into an L-shape to integrally form the fixing parts with the lower ends of the rod-shaped members 20A, 20B, the strength of the bent parts decreases. Therefore, in this embodiment, when the lower ends of the rod-shaped members 20A, 20B embedded in the planned cutting region 34 of the wall body 31 are fixed (anchored) to the bottom 32, the joint devices 1A, 1B are used to replace the fixing parts with the reinforcing bars 10A, 10B.

[0048] If the rod-shaped member 20 is used as a shear reinforcement, its end needs to be hooked onto a main bar or the like, and therefore the end needs to be hooked. However, when this hooking is performed, the tensile strength is reduced at the bent portion. In this regard, by using the joint device 1 to replace the portion requiring the hooking with the reinforcing bar 10, it is possible to prevent the reduction in tensile strength at the bent portion due to the hooking.

[0049] According to this embodiment, the joint device 1 connects the end 11 of the reinforcing bar 10 and the end 21 of the resin rod-shaped member 20. The joint device 1 includes a tubular member 2 into which the end 11 of the reinforcing bar 10 is inserted from an opening 2b on one end side into a hollow portion 2a and the end 21 of the rod-shaped member 20 is inserted from an opening 2c on the other end side into the hollow portion 2a, and a grout material 3 filled in the hollow portion 2a of the tubular member 2 into which the end 11 of the reinforcing bar 10 and the end 21 of the rod-shaped member 20 are inserted. Therefore, the joint device 1 can be simply configured.

[0050] According to the present embodiment, the grout material 3 includes an expansive material. The grout material 3 has an expansion pressure of 20 N / mm 2 It is preferable that the resistance is 30N / mm or more. 2 It is more preferable that the above is the case. This allows the joint device 1 to firmly connect the end 11 of the reinforcing bar 10 and the end 21 of the rod-shaped member 20. The grout material 3 may contain non-shrink mortar.

[0051] According to this embodiment, the rod-shaped member 20 is made of resin (synthetic resin), preferably made of fiber reinforced plastic (FRP), more preferably made of glass fiber reinforced plastic (GFRP) or carbon fiber reinforced plastic (CFRP), and particularly preferably made of carbon fiber reinforced plastic (CFRP). The rod-shaped member 20 has a Young's modulus of 80000 N / mm 2 It is preferable that the resistance is 100,000 N / mm or more. 2 More preferably, it is equal to or greater than this.

[0052] According to this embodiment, the diameter D2 of the rod-shaped member 20 is smaller than the diameter D1 of the reinforcing bar 10. Here, it is preferable that the diameter of the reinforcing bar 10 is determined so as to have performance (e.g., tensile strength) equivalent to that of the rod-shaped member 20. Furthermore, the reinforcing bar 10 may have bent portions (e.g., bent portions 10AD, 10BD).

[0053] According to the present embodiment, the shaft 30, which is an example of a concrete structure, is one in which the joint devices 1A, 1B, the reinforcing bars 10A, 10B, and the rod-shaped members 20A, 20B are embedded. Therefore, it is possible to cut the intended cutting area 34, which is the portion of the shaft 30 in which the rod-shaped members 20A, 20B are embedded.

[0054] According to the present embodiment, the cutting method of the shaft 30, which is an example of a concrete structure, includes cutting the intended cutting area 34, which is the portion of the shaft 30 where the rod members 20A and 20B are embedded. Therefore, a portion of the shaft 30 can be easily cut.

[0055] According to this embodiment, the cutting method of the shaft 30, which is an example of a concrete structure, includes constructing a ground improvement body 50 in the ground, constructing the shaft 30 in a construction space 36, which is a space formed by excavating the ground so as to include at least a part of the ground improvement body 50, and cutting a planned cutting area 34, which is a part of the shaft 30 where the rod-shaped members 20A and 20B are buried. Therefore, a part of the shaft 30 can be easily cut.

[0056] According to the present embodiment, in the cutting method for the shaft 30, which is an example of a concrete structure, an opening (e.g., the starting shaft mouth 40) is formed in the shaft 30 by cutting the intended cutting area 34. Therefore, the opening can be formed by simply cutting a part of the shaft 30.

[0057] In this embodiment, an example is shown in which an end 11 of a reinforcing bar 10 is connected to one end 21 of a rod-shaped member 20 via a joint device 1, but it goes without saying that in addition to this, an end of another reinforcing bar may also be connected to the other end of the rod-shaped member 20 via a joint device 1.

[0058] The concrete structure to which the joint device described in this embodiment is applied is not limited to a shaft, but may be, for example, a tunnel lining. The concrete structure to which the joint device described in this embodiment is applied may be a partition wall separating an underground space from the surrounding ground.

[0059] As is apparent from the above description, the illustrated embodiments are merely illustrative of the present invention, and it goes without saying that the present invention encompasses various improvements and modifications made by those skilled in the art within the scope of the claims, in addition to those directly shown in the described embodiments. The claims as originally filed were as follows: [Claim 1] A joint device for connecting an end of a reinforcing bar and an end of a resin rod-shaped member, a cylindrical member in which the end of the reinforcing bar is inserted into a hollow portion from an opening on one end side, and the end of the rod-shaped member is inserted into the hollow portion from an opening on the other end side; A grout material is filled in the hollow portion of the tubular member into which the end of the reinforcing bar and the end of the rod-shaped member are inserted; A coupling device comprising: [Claim 2] The coupling device of claim 1 , wherein the grout material comprises an expansive material. [Claim 3] 3. The joint device according to claim 1 or 2, wherein the diameter of the rod-shaped member is smaller than the diameter of the reinforcing bar. [Claim 4] 4. A concrete structure in which the joint device according to any one of claims 1 to 3, the reinforcing bar, and the rod-shaped member are embedded. [Claim 5] 5. A method for cutting a concrete structure, comprising: cutting a portion of the concrete structure according to claim 4 in which the rod-shaped members are embedded. [Claim 6] Constructing a ground improvement body underground; Constructing the concrete structure according to claim 4 in a space formed by excavating the ground so as to include at least a part of the ground improvement body; and cutting a portion of the concrete structure in which the rod-shaped member is embedded; A method for cutting a concrete structure, comprising: [Claim 7] 7. The method for cutting a concrete structure according to claim 5 or 6, further comprising forming an opening in the concrete structure by cutting. [Explanation of symbols]

[0060] 1, 1A, 1B... coupling device, 2... cylindrical member, 2a... hollow portion, 2b, 2c... opening, 3... grout material, 4, 5... sealing member, 4a, 5a... through hole, 10, 10A, 10B... reinforcing bar, 10AC, 10BC... straight portion, 10AD, 10BD... curved portion, 10AE, 10BE... straight portion, 11... end, 20, 20A, 20B... rod-shaped member, 21... end, 30... shaft, 31... wall body, 32... bottom, 33... internal space, 34... planned cutting area, 35... planned construction area, 36... construction space, 37... bottom excavation surface, 38... side excavation surface, 40... starting tunnel entrance, 50... ground improvement body, 60... tunnel, D1, D2... diameter

Claims

1. A method for constructing a concrete structure in a space formed by excavating ground, comprising: Connecting one end of a reinforcing bar to a lower end of a resin rod-shaped member extending vertically in the space via a joint device; Constructing a wall of the concrete structure by pouring concrete so as to encase the other end of the reinforcing bar, the joint device, and the rod-shaped member while leaving a portion of the other end of the reinforcing bar exposed; Pouring concrete so as to encase a portion of the other end of the reinforcing bar to construct a bottom of the concrete structure; Including, The joint device and the reinforcing bar are located lower than the upper surface of the bottom of the concrete structure, The coupling device comprises: A cylindrical member extending in a vertical direction, with one end of the reinforcing bar being inserted into a hollow portion from an opening on a lower end side and with a lower end of the rod-shaped member being inserted into the hollow portion from an opening on an upper end side; A grout material is filled in the hollow portion of the tubular member into which one end of the reinforcing bar and the lower end of the rod-shaped member are inserted; Equipped with How to build a concrete structure.

2. A method for constructing a concrete structure in a space formed by excavating ground, comprising: Connecting one end of a reinforcing bar to a lower end of a resin rod-shaped member extending vertically in the space via a joint device; Constructing a wall of the concrete structure by pouring concrete so as to encase the other end of the reinforcing bar, the joint device, and the rod-shaped member while leaving a portion of the other end of the reinforcing bar exposed; Pouring concrete so as to encase a portion of the other end of the reinforcing bar to construct a bottom of the concrete structure; Including, A method of constructing a concrete structure, wherein the joint device and the reinforcing bar are located below a top surface of the bottom of the concrete structure.

3. The reinforcing bar has a first straight portion extending vertically and a second straight portion extending horizontally from a lower end of the first straight portion, and extends in an L-shape; One end of the reinforcing bar is an upper end of the first straight portion, 3. The method for constructing a concrete structure according to claim 1 or 2, wherein a portion of the other end side of the reinforcing bar is at least a portion of the second straight portion.

4. The method further includes constructing a ground improvement body in the ground prior to forming the space, A method for constructing a concrete structure according to any one of claims 1 to 3, wherein the space is formed by excavating the ground so as to include at least a portion of the ground improvement body.

5. A method for constructing a concrete structure described in any one of claims 1 to 4, wherein the diameter of the rod-shaped member is smaller than the diameter of the reinforcing bar so that the tensile strength of the rod-shaped member is equivalent to the tensile strength of the reinforcing bar.

6. A method for constructing a concrete structure described in any one of claims 1 to 5, wherein the concrete structure is a vertical shaft.

7. A method for constructing a concrete structure comprising the steps of: cutting a portion of a wall of the concrete structure constructed by the method for constructing a concrete structure according to any one of claims 1 to 6, in which the rod-shaped members are embedded, thereby forming an opening in the wall of the concrete structure; A method for cutting a concrete structure, wherein a lower end of an opening in a wall of the concrete structure is adjacent to an upper surface of a bottom of the concrete structure.

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