Method and structure for reinforcing columns

Abstract

The present invention provides a method and structure for reinforcing columns that allows for easy replacement of existing columnar structures using erected columns and enables the firm fixation of the erected columns. [Solution] The method for reinforcing a column includes the steps of: separating an existing vertical columnar body TP into a lower pipe TPD and an upper pipe TPU; inserting the reinforcing pipe section NPD at the bottom of the upright column NP into the upper hollow section HL4 of the lower pipe TPD; and injecting a filler FM into the gap SP2 between the reinforcing pipe section NPD and the lower pipe TPD through an injection hole 4 provided in the reinforcing pipe section NPD.

Description

[[TECHNICAL FIELD]]

[0001] The present invention relates to a column reinforcing method and a reinforcing structure for reinforcing an existing columnar body. [[BACKGROUND ART]]

[0002] As a reinforcing measure against deterioration of an existing columnar body, it has been practiced to cut the existing columnar body into a lower part and an upper part, and replace the upper part with a newly installed column. For example, in order to replace an existing concrete column 7, the existing concrete column 7 is cut to form an existing base 2, a diameter-expanding pipe 3 is engaged with the existing base 2, and a time-curable material 4 is filled inside the diameter-expanded portion 32. An existing concrete column replacement method is disclosed (e.g., Patent Document 1). [[PRIOR ART DOCUMENTS]] [[PATENT DOCUMENTS]]

[0003] [[Patent Document 1]] Japanese Unexamined Patent Application Publication No. 2016-98619 [[SUMMARY OF THE INVENTION]] [[Problem to be Solved by the Invention]]

[0004] However, from the viewpoint of easily replacing an existing columnar body using a newly installed column and firmly fixing the newly installed column, there is room for improvement in the installation of the newly installed column.

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to provide a column reinforcing method and a reinforcing structure that can easily replace an existing columnar body using an erected column and firmly fix the erected column. [[Means for Solving the Problem]]

[0006] A method for reinforcing a column to achieve the above objective is characterized by including the steps of: separating a vertically installed columnar body into a lower pipe and an upper pipe; inserting the reinforcing pipe portion at the lower part of the upright column into the hollow part of the lower pipe; and injecting a filler into the gap between the reinforcing pipe portion and the lower pipe through an injection hole provided in the reinforcing pipe portion.

[0007] The reinforcing structure according to the present means for achieving the above objective comprises a lower pipe formed by separating an existing columnar body into upper and lower sections, an upright column having a reinforcing pipe section at the bottom and an upper pipe section at the top, with the reinforcing pipe section inserted into the hollow part of the lower pipe, and a filler injected into the gap between the outer surface of the reinforcing pipe section and the inner surface of the lower pipe, wherein the upright column has an outer covering that covers the outer circumference near the upper end of the lower pipe. [Effects of the Invention]

[0008] The present invention provides a method for reinforcing a pole, which allows for easy replacement of a utility pole by inserting the reinforcing pipe section at the bottom of the pole into the hollow section of the lower pipe. Furthermore, since the filler is injected into the gap between the reinforcing pipe section and the lower pipe through an injection hole provided in the reinforcing pipe section that directly leads to the gap, it is possible to reliably inject the filler into the gap, and the pole can be firmly fixed to the lower pipe. [Brief explanation of the drawing]

[0009] [Figure 1] This is an explanatory diagram of the reinforcing structure according to the first embodiment. [Figure 2] This is an explanatory diagram of a column reinforcement method according to the first embodiment. [Figure 3] This is an explanatory diagram of a column reinforcement method according to the first embodiment. [Figure 4] This is an explanatory diagram of a column reinforcement method according to the first embodiment. [Figure 5] This is an explanatory diagram of a column reinforcement method according to the first embodiment. [Figure 6] This is an explanatory diagram of a column reinforcement method according to the first embodiment. [Modes for carrying out the invention]

[0010] [First Embodiment] An example of a column reinforcement structure according to the first embodiment will be described with reference to the drawings. Figure 1 shows reinforcement structure 1 as an example of a reinforcement structure.

[0011] The reinforcing structure 1 comprises a lower pipe TPD whose lower part is embedded in the ground level (GL), and an upright column NP which is inserted into the lower pipe TPD from above and fixed in place.

[0012] The lower pipe TPD is formed by separating an existing concrete utility pole at ground level (GL) into upper and lower sections and removing the upper pipe. Because the existing utility pole has a hollow section, the lower pipe TPD has a first hollow section HL1. Above the first hollow section HL1, an upper hollow section HL4 with a larger diameter than the first hollow section HL1 is continuously formed, and a stepped section 3 for holding the erected pole NP is formed at the boundary between the first hollow section HL1 and the upper hollow section HL4.

[0013] The erected column NP functions as a replacement for the removed upper pipe, and its material is not particularly limited, but can be SS material (Structural Steel Material) or STKR material (Steel Tube for Structural Rectangular Material), etc. The erected column NP has a reinforcing pipe section NPD at the bottom and an upper pipe section NPU at the top. The reinforcing pipe section NPD has a substantially conical connecting section NPD1 at the top and a cylindrical hanging section NPD2 at the bottom. The connecting section NPD1 covers the upper end surface of the lower pipe TPD, and a gap SP1 is created between the inner circumferential surface of the connecting section NPD1 and the upper end surface of the lower pipe TPD. The hanging section NPD2 is inserted into the upper hollow section HL4, and a gap SP2 is created between the outer circumferential surface of the hanging section NPD2 and the inner circumferential surface of the lower pipe TPD.

[0014] An injection hole 4 is formed near the lower end of the hanging section NPD2, extending from the upper hollow section HL4 to the gap SP2, for injecting the filler FM. A pad 5 is sandwiched between the lower end of the hanging section NPD2 and the stepped section 3, and a bottom plate 6 is fixed to the inner circumferential surface of the lower end of the hanging section NPD2, contacting the pad 5.

[0015] The upper pipe portion NPU has a cylindrical shape having a hollow portion 7 continuous with the upper hollow portion HL4, and is integrally continuous with the connection portion NPD1. The upper pipe portion NPU may have the same outer diameter as the lower pipe TPD. A mounting hole 8 that penetrates from the outside of the upper pipe portion NPU to the hollow portion 7 and is for attaching an injection pipe when injecting the filler FM is provided in an intermediate portion of the upper pipe portion NPU.

[0016] The upright column NP includes a ring-shaped exterior body 9 that covers the outer periphery near the upper end of the lower pipe TPD, and a gap SP3 is formed between the outer peripheral surface near the upper end of the lower pipe TPD and the inner peripheral surface of the exterior body 9. The exterior body 9 penetrates from the gap SP3 to the outside of the exterior body 9, and is provided with a plurality of air vent holes 10 for evacuating air in the gap SP3 when injecting the filler FM. The exterior body 9 is fixed near the lower end of the upper pipe portion NPU by welding, fusion bonding, an adhesive, or the like.

[0017] The reinforcing structure 1 includes the filler FM continuously injected from the gap SP2 to the gap SP3 via the gap SP1. In addition to mortar, the filler FM may be an anchor gel such as epoxy-based, cement-based, polyester-based, vinyl ester-based, acrylic-based, or a mixture thereof, and the material is not particularly limited.

[0018] <Reinforcing Method for Column Body> A reinforcing method for a column body for forming the reinforcing structure 1 will be described below. The steps of the column body reinforcing method are an example, the order is not limited, and other steps may be included between respective steps.

[0019] First, at a utility pole reinforcement location where the utility pole TP is already installed vertically on the ground GL, an optimal cutting target portion CS for replacing the deteriorated utility pole TP is determined. Next, as shown in Fig. 2(a), the utility pole TP is cut at the cutting target portion CS by a cutting device such as a pipe saw (not shown), and the utility pole TP is divided into the lower pipe TPD and the upper pipe TPU. At this time, it is preferable to grip the upper pipe TPU using a boom or the like of a pole erecting truck. The cutting device is not particularly limited, and may be a saw blade with a reciprocating cutting blade, an endless chainsaw, or the like. The upper pipe TPU is removed, and the lower pipe TPD remains.

[0020] Next, as shown in Fig. 2(b), a drill holding device 20 is attached to the lower pipe TPD, and a core drill 22 is attached to a rotating shaft 23 of the drill holding device 20. The core drill 22 includes a cylindrical member 40, and a plurality of cutting blades 41 are arranged in a substantially circular shape at the lower end of the cylindrical member 40. The core drill 22 has a hollow portion 42 inside the cylindrical member 40 and the plurality of cutting blades 41. The core drill 22 is positioned such that the center line CL1 of the lower pipe TPD coincides with the center line CL2 of the core drill 22.

[0021] Next, as indicated by the broken line in Fig. 2(b), the core drill 22 is rotationally driven, and the drill holding device 20 slides downward along the guide 24. Accordingly, the plurality of cutting blades 41 cut the outer side of the first hollow portion HL1 of the lower pipe TPD into a circular shape while rotating around the center line CL2, thereby forming a cylindrical second hollow portion HL2(1) on the outer side of the first hollow portion HL1.

[0022] Next, the drill holding device 20 slides upward along the guide 24, and the core drill 22 is separated from the first hollow portion HL1. At this time, as shown in Fig. 3(a), a core 45(1) is formed inside the second hollow portion HL2(1). The separated drill holding device 20 and core drill 22 may be temporarily retracted from above the first hollow portion HL1.

[0023] Next, as shown in Figure 3(b), a splitter 43 supported at its center by a rod 46 is inserted into the first hollow section HL1 of the lower pipe TPD, and the multiple wedges 44 of the splitter 43 are spread out and pressed into the inner circumferential surface of the first hollow section HL1. At this time, the vertical position of the wedges 44 coincides with the lower end of the second hollow section HL2(1), and the centerline CL4 of the splitter 43 coincides with the centerline CL1. With the multiple wedges 44 pressed into the inner circumferential surface of the first hollow section HL1, the cylindrical core 45(1) inside the second hollow section HL2(1) is separated from the lower pipe TPD. At this time, the multiple wedges 44 engage with the lower end of the core 45(1). Next, the splitter 43 is removed upward from the lower pipe TPD, and the core 45(1) with the multiple wedges 44 engaged is pulled upward from the lower pipe TPD and removed. Guide 24 may be used to insert and remove the splitter 43 into and from the lower pipe TPD.

[0024] Next, as shown in Figure 4(a), the connecting shaft 25 is fixed to the connecting portion 26 of the core drill 22, the rotating shaft 23 is fixed to the connecting shaft 25, and the core drill 22 is connected to the rotating shaft 23 via the connecting shaft 25. After that, the core drill 22 is slid downward and fitted into the hollow portion HL5 after the core 45(1) has been removed.

[0025] Next, as shown in Figure 4(b), the drill holder 20 is again rotated and slid downward along the guide 24, causing the core drill 22 to descend and cut the outside of the first hollow section HL1 into a cylindrical shape. At this time, the center line CL1 of the lower pipe TPD and the center line CL2 of the core drill 22 coincide.

[0026] Next, the drill holder 20 and core drill 22 are slid upward along the guide 24, after which the connecting shaft 25 is removed from the rotating shaft 23 and the connecting part 26, the rotating shaft 23 is fixed to the connecting part 26, and the drill holder 20 and core drill 22 are further slid upward along the guide 24. As a result, the core drill 22 is pulled out and removed from the lower pipe TPD. The removed drill holder 20 and core drill 22 are then withdrawn. At this time, as shown in Figure 5(a), in the lower pipe TPD, a cylindrical second hollow part HL2(2) is formed on the outside of the cylindrical first hollow part HL1. When the center line CL1 and the center line CL2 coincide, the center line CL1 coincides with the center line CL3(2) of the second hollow part HL2(2).

[0027] Next, as shown in Figure 5(b), the splitter 43 is inserted into the first hollow section HL1 of the lower pipe TPD, and the multiple wedges 44 of the splitter 43 are spread out and pressed into the inner circumferential surface of the first hollow section HL1. At this time, the vertical position of the wedges 44 coincides with the lower end of the second hollow section HL2(2), and the centerline CL4 of the splitter 43 coincides with the centerline CL1. The press-fitting of the multiple wedges 44 into the first hollow section HL1 forms a stepped section 3, and the cylindrical core 45(2) inside the second hollow section HL2 is separated from the lower pipe TPD. At this time, the multiple wedges 44 engage with the lower end of the core 45(2). Next, the splitter 43 is pulled upward from the lower pipe TPD, and the core 45(2) with the multiple wedges 44 engaged is pulled upward from the lower pipe TPD. Guide 24 may be used to insert and remove the splitter 43 into and from the lower pipe TPD.

[0028] As the core 45 is removed from the first hollow section HL1, an upper hollow section HL4 is formed on top of the first hollow section HL1, as shown by the solid line in Figure 6(a). Next, a water-sealing ring 27 is fixed to the outer circumference near the upper end of the lower pipe TPD. The material of the water-sealing ring 27 is not particularly limited and can be rubber, silicone, or synthetic resin, etc.

[0029] Furthermore, as shown by the dashed line in Figure 6(a), the pad 5 is inserted into the upper hollow section HL4 and abuts against the stepped section 3, and the reinforcing pipe section NPD of the newly prepared upright column NP is inserted into the upper hollow section HL4 and the bottom plate 6 abuts against the upper surface of the pad 5. The lower end of the reinforcing pipe section NPD is restricted from descending by the stepped section 3 via the pad 5, and the reinforcing pipe section NPD is positioned in the upper hollow section HL4. Alternatively, the upright column NP may be inserted into the upper hollow section HL4 by sliding a holder (not shown) that holds the upright column NP downward along a vertically installed guide rail (not shown) to align the center line CL1 of the lower pipe TPD with the center line CL5 of the hanging section NPD2.

[0030] An injection pipe 28 is attached to the hollow section 7 of the upright column NP, extending from the injection hole 4 through the mounting hole 8 to the outside of the upper pipe section NPU. A gap SP1 is formed between the connecting section NPD1 and the upper end surface of the lower pipe TPD, a gap SP2 is formed between the hanging section NPD2 and the inner circumferential surface of the lower pipe TPD, and a gap SP3 is formed between the outer circumferential surface near the upper end of the lower pipe TPD and the inner circumferential surface of the outer casing 9. By aligning the center line CL5 of the hanging section NPD2 with the center line CL1, the widths of gaps SP1, SP2, and SP3 become equal in plan view. The lower end of the outer casing 9 is fitted into the watertight ring 27, sealing the lower end of gap SP3.

[0031] Next, as shown in Figure 6(b), an air vent pipe 29 is connected to the air vent hole 10, and an injection device (not shown) is connected to the upper end of the injection pipe 28, and the filler FM is injected into the injection pipe 28 from the upper end of the injection pipe 28. The injection device includes, for example, a tank, a pump, and a pump drive device. An injection device equipped with a pump and a pump drive device can inject the filler FM under pressure.

[0032] The filler FM injected into the injection pipe 28 flows into the gap SP2 through the injection hole 4, then flows through gap SP1 to gap SP3, and is sealed by the watertight ring 27. At this time, the air in gaps SP1, SP2, and SP3 is discharged to the outside of the upright column through the air vent pipe 29, so that the filler FM flows evenly into gaps SP1, SP2, and SP3. The material of the filler FM is not particularly limited, but it is preferable that it be a highly fluid mortar that can spread even if gaps SP1 etc. are narrow. Furthermore, it is preferable that the filler FM is a fast-setting mortar that dries and hardens quickly and gains strength quickly. Furthermore, it is preferable that the filler FM is a non-shrink mortar that does not shrink even after hardening, thereby preventing the formation of voids.

[0033] Once the injected mortar hardens, the injection pipe 28 is removed from the injection hole 4 and the mounting hole 8, and the air vent pipe 29 is removed from the air vent hole 10, forming the reinforcing structure 1 (shown in Figure 1).

[0034] <Effects of the reinforcing structure> The reinforcing structure 1 has an outer covering 9 that covers the outer circumference near the upper end of the lower pipe TPD, so the area near the upper end of the lower pipe TPD can be firmly reinforced. Moreover, since the filler FM is injected into the gap between the outer circumference near the upper end of the lower pipe TPD and the outer covering 9, the outer covering 9 adheres to the outer circumference near the upper end of the lower pipe TPD via the filler FM, increasing the adhesive force between the upright column NP and the lower pipe TPD, and allowing the upright column NP to be firmly fixed to the lower pipe TPD. Furthermore, the area near the upper end of the lower pipe TPD can be firmly fixed to the lower pipe TPD by sandwiching it between the filler FM in gap SP2 and the filler FM in gap SP3. As a result, the strength of the reinforcing structure 1 in which the upright column NP is fixed to the lower pipe TPD can be increased.

[0035] <Effects of column reinforcement methods> The pole reinforcement method according to the present invention allows for easy replacement of the utility pole TP by inserting the reinforcing pipe section NPD at the bottom of the erected pole NP into the upper hollow section HL4 of the lower pipe TPD. Furthermore, since the filler material FM is injected into the gap SP2 between the reinforcing pipe section NPD and the lower pipe TPD through an injection hole 4 provided in the reinforcing pipe section NPD that directly connects to the gap SP2, the filler material FM can be reliably and easily injected into the gap SP2. In addition, it becomes possible to inject the filler material FM into the entire gap SP2, allowing the erected pole NP to be firmly fixed to the lower pipe TPD. Moreover, if the filler material FM is injected by pressurizing through the injection hole 4 using an injection device equipped with a pump or the like, the filler material FM can be injected into the entire gap SP2 even if the width of the gap SP2 is narrow.

[0036] Furthermore, by expanding the first hollow section HL1 of the lower pipe TPD to form the upper hollow section HL4 before inserting the reinforcing pipe NPD into the lower pipe TPD, a larger reinforcing pipe NPD can be inserted, thereby increasing the strength of the formed reinforcing structure 1. In addition, by expanding the first hollow section HL1, a sufficient gap SP2 for injecting the filler FM can be formed.

[0037] Furthermore, since the filler FM is injected into the gap SP2 etc. through the injection hole 4 provided near the lower end of the reinforcing pipe NPD, the filler FM flows into the lower part of the gap SP2, and the filler FM can be injected evenly throughout the entire gap SP2. If mortar, which has viscosity and therefore adheres well to the member, is used as the filler FM, pouring the filler FM into the gap SP2 from above may result in the filler FM not reaching near the lower end of the gap SP2. However, if the filler FM is injected by pressure through the injection hole 4 provided near the lower end of the reinforcing pipe NPD, for example, this problem cannot occur. [Explanation of symbols]

[0038] 1: Reinforcement structure, 3: Stepped section, 4: Injection hole, 5: Pad, 6: Bottom plate, 7: Hollow section of upper pipe, 8: Mounting hole, 9: Outer casing, 10: Air vent hole 45(1): Core, 45(2): Core TP: Utility pole, TPD: Lower pipe, TPU: Upper pipe NP: Standing column, NPD: Reinforcement pipe section, NPU: Upper pipe section, NPD1: Connection section, NPD2: Drooping section HL1: First hollow section of the lower pipe, HL2(1): Second hollow section of the lower pipe, HL2(2): Second hollow section of the lower pipe, HL3: Hollow section of the upright column, HL4: Upper hollow section of the lower pipe, HL5: Hollow section after core removal SP1: Gap between the inner surface of the connection and the upper end surface of the lower pipe; SP2: Gap between the outer surface of the hanging part and the inner surface of the lower pipe; SP3: Gap between the outer surface near the upper end of the lower pipe and the inner surface of the outer casing. CL1: Centerline of the lower pipe, CL2: Centerline of the core drill, CL3(1): Centerline of the second hollow section, CL3(2): Centerline of the second hollow section, CL4: Centerline of the splitter, CL5: Centerline of the hanging section

Claims

1. The process involves separating a vertically installed columnar body into a lower pipe and an upper pipe, The process involves inserting the reinforcing pipe section at the bottom of the erected column into the hollow section of the lower pipe, The process involves injecting a filler into the gap between the reinforcing pipe and the lower pipe through an injection hole provided in the reinforcing pipe, A method for reinforcing a column, including the column itself.

2. After the step of separating the columnar body into the lower pipe and the upper pipe, and before the step of inserting the reinforcing pipe into the lower pipe, the process includes expanding the hollow portion of the lower pipe. The method for reinforcing a column according to claim 1.

3. The step of injecting the filler includes injecting the filler through the injection hole provided near the lower end of the reinforcing pipe section. The method for reinforcing a column according to claim 1.

4. The lower pipe was formed by separating the existing columnar body into upper and lower sections, A standing column having a reinforcing pipe section at the bottom and an upper pipe section at the top, wherein the reinforcing pipe section is inserted into the hollow part of the lower pipe, A filler injected into the gap between the outer surface of the reinforcing pipe and the inner surface of the lower pipe, Equipped with, The aforementioned upright column has an outer covering that covers the outer circumference near the upper end of the lower pipe. Reinforcement structure.

5. The filler was injected into the gap between the outer circumference near the upper end of the lower pipe and the outer casing. The reinforcing structure according to claim 4.

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