Tie rod installation method and tie rod structure

Abstract

To provide a tie rod installation method for restoring the function of an existing damaged tie rod without releasing the tension of the tie rod.SOLUTION: A tie rod installation method uses at least a tension-bearing tie rod 9 for bearing the tension of an existing tie rod 4, and a branch joint 8 for connecting the tension-bearing tie rod 9 to the existing tie rod 4. This makes it possible to restore the function of the existing tie rod 4 that has been damaged or otherwise damaged, without releasing the tension.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a tie rod construction method and a tie rod structure for connecting a pair of structures arranged at a distance from one another and stabilizing one of the structures by its tension. [Background technology]

[0002] Generally, a tie rod is a rod-shaped structural member that stabilizes a pair of structures by tension, i.e., a connecting rod. Tie rods are often used in the foundations of quays, revetments, breakwaters, dams, and water gates in ports and rivers. Tie rods are used as tension members between a pair of structures, such as a sheet pile structure (steel sheet pile or steel pipe sheet pile) and a bracing, between a sheet pile wall and a bracing, and between sheet piles and sheet piles, in the steel sheet pile method, steel pipe sheet pile method, and steel sheet pile double wall method. More specifically, tie rods are connected in series and in parallel between a sheet pile structure and a bracing on a quay, for example, and are used to pull the sheet pile structure toward the land side to prevent the sheet pile structure from tilting toward the sea due to the earth pressure that the sheet pile structure receives from the land side.

[0003] Therefore, if a tie rod is found to have a partial lack of load-bearing capacity (required tension) due to deterioration over time, i.e., damage, etc., it is necessary to change its location and install a new tie rod and bracing work, or to temporarily release the tension of the existing damaged tie rod and replace it with a new tie rod, i.e., to restore its original function.

[0004] However, if the location is changed and new tie rods and bracing works are installed, the construction work will be large-scale and not appropriate from a cost perspective. On the other hand, if the location is changed and new tie rods and bracing works are not installed, the tension of the damaged existing tie rods will be temporarily released, but this also requires measures to safely release the tension, i.e. measures to prevent the sheet pile structure from tilting toward the sea, and the construction work will be large-scale and not appropriate from a cost perspective.

[0005] Patent Document 1 discloses a method for renovating an existing revetment or quay, which includes the steps of improving the ground on the rear side of an existing steel sheet pile and constructing a ground improvement body, removing the existing steel sheet pile and the tie rods supporting the existing steel sheet pile, installing a covering member on the front side of the ground improvement body at the position where the existing steel sheet pile was installed, and filling material between the covering member and the ground improvement body. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2016-108822 A Summary of the Invention [Problem to be solved by the invention]

[0007] The method of renovating an existing revetment or quay wall described in the above-mentioned Patent Document 1 cannot solve the problem of restoring the function of the existing tie rods that have been damaged or the like.

[0008] The present invention has been made in consideration of the above points, and aims to provide a tie rod installation method and a tie rod structure that can restore the function of an existing tie rod that has been damaged, for example, without releasing the tension of the existing tie rod. [Means for solving the problem]

[0009] As a means for solving the above problem, the invention relating to the tie rod installation method of claim 1 is a method for installing a tie rod that extends between a pair of structures arranged at a distance and stabilizes one of the structures by its tension, and is characterized by using at least a tension-bearing tie rod for bearing the tension of an existing tie rod, and a branch joint for connecting the tension-bearing tie rod to the existing tie rod. In the invention of claim 1, at least a tension-bearing tie rod and a branch joint are used, so that the existing tie rod, which has been damaged or otherwise, can be replaced with a new tie rod while the tension of the existing tie rod is being borne by the tension-bearing tie rod, or the existing tie rod and the new tie rod can both be buried while the tension of the existing tie rod is still borne by the tension-bearing tie rod, and the function of the existing tie rod can be restored without releasing the tension of the existing tie rod.

[0010] The invention relating to the tie rod installation method of claim 2 is the invention described in claim 1, characterized in that it includes an installation step of attaching the branch joint to another existing tie rod that is connected to the existing tie rod via a turnbuckle, a connection step of connecting the branch joint to the one of the structures with the tension-bearing tie rod, and a replacement step of removing the existing tie rod from the turnbuckle and the one of the structures and replacing it with a new tie rod, and then removing the branch joint and the tension-bearing tie rod. In the invention of claim 2, the attachment step and the connection step temporarily connect a tension-bearing tie rod to the damaged existing tie rod via a branch joint, so that the tension of the existing tie rod is borne by the tension-bearing tie rod. Meanwhile, in the replacement step, the existing tie rod is replaced with a new tie rod, so that the function of the existing tie rod can be restored without releasing the tension of the existing tie rod.

[0011] The invention relating to the tie rod construction method of claim 3 is the invention described in claim 1, characterized in that it includes an installation step of attaching the branch joint to another existing tie rod that is connected to the existing tie rod via a turnbuckle, a connection step of connecting the branch joint to the one structure with the tension-bearing tie rod, and an burying step of burying the existing tie rod, the branch joint and the tension-bearing tie rod in the ground. In the invention of claim 3, the attachment step and the connection step connect the tension-bearing tie rod to the damaged existing tie rod via the branch joint, and the tension of the existing tie rod is borne by the tension-bearing tie rod. Then, the burying step buries the existing tie rod, the branch joint, and the tension-bearing tie rod in the ground, thereby restoring the function of the existing tie rod without releasing the tension of the existing tie rod.

[0012] The invention relating to the tie rod structure of claim 4 is a tie rod structure extending between a pair of structures spaced apart and stabilizing one of the structures by its tension, characterized in that it includes a tension-bearing tie rod connected to an existing tie rod via a branch joint. In the invention of claim 4, the tension of the existing tie rod that has been damaged or the like is not released, but the tension of the existing tie rod is borne by the tension-bearing tie rod, thereby restoring its function.

[0013] The invention relating to the tie rod structure of claim 5 is the invention described in claim 4, characterized in that the branch joint has an insertion hole through which the existing tie rod is inserted, and a connecting hole which connects the tension-bearing tie rod so that it can rotate freely around its axial end. In the invention of claim 5, the tension-bearing tie rod is freely rotatable around the connecting hole of the branch joint (the base end of the tension-bearing tie rod), so that the tip of the tension-bearing tie rod can be easily connected to one of the structures.

[0014] The invention relating to a tie rod structure of claim 6 is the invention described in claim 5, characterized in that the branch joint is configured to be separable. According to the invention of claim 6, since the branch joint is configured to be separable, the branch joint can be easily connected to the outer periphery of the existing tie rod. Effect of the Invention

[0015] According to the tie rod installation method and tie rod structure of the present invention, it is possible to restore the function of an existing tie rod that has been damaged, for example, without releasing the tension of the existing tie rod. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a side view of the tie rod structure according to the present embodiment. [Diagram 2] FIG. 2 shows a branch joint employed in the tie rod structure according to this embodiment, where (a) is a front view and (b) is a side view. [Diagram 3] FIG. 3 shows the tension-bearing tie rod and the newly installed split tie rod employed in this embodiment, where (a) is a plan view and (b) is a side view. [Figure 4] FIG. 4 is a schematic diagram showing a stepwise process of the tie rod installation method according to the first embodiment. [Diagram 5] FIG. 5 is a schematic diagram showing a step-by-step method of installing a tie rod according to the first embodiment. [Figure 6] FIG. 6 is a schematic diagram showing a stepwise process of the tie rod installation method according to the first embodiment. [Figure 7] FIG. 7 is a schematic diagram showing a stepwise process of the tie rod installation method according to the first embodiment. [Figure 8] FIG. 8 is a schematic diagram showing a stepwise process of the tie rod installation method according to the first embodiment. [Figure 9] FIG. 9 is a schematic diagram showing a stepwise process of the tie rod installation method according to the first embodiment. [Figure 10] FIG. 10 is a schematic diagram showing a number of existing tie rods extending between a sheet pile structure constituting a quay wall and a retaining structure. [Figure 11] FIG. 11 is a side view showing a state in which a plurality of existing tie rods are connected in series. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described in detail with reference to Figs. 10, between a pair of structures arranged at a distance from each other, for example, between a sheet pile structure 51 (steel sheet pile or steel pipe sheet pile) constituting a quay 50 and a bracing work 53, a plurality of existing tie rods 4, 4 extend as tension members, stabilizing the sheet pile structure 51 (one of the structures) by their tension. In more detail, referring to FIG. 11, between the sheet pile structure 51 and the bracing work 53, for example, a plurality of existing tie rods 4, 4 are arranged connected in series by turnbuckles 5 or ring joints 6, and a plurality of existing tie rods 4, 4 connected in series are arranged in parallel.

[0018] 1, the tie rod structure 1 according to this embodiment restores the function of the existing tie rod 4 connected to the sheet pile structure 51 (applying tension between the sheet pile structure 51 and the bracing 53) when the existing tie rod 4 cannot fully perform its function due to damage or the like. Specifically, the tie rod structure 1 according to this embodiment includes a tension-bearing tie rod 9 connected via a branch joint 8 to another existing tie rod 4A connected to the existing tie rod 4 via a turnbuckle 5. In this embodiment, one axial end of the existing tie rod 4 is formed into a male thread portion 15, and the male thread portion 15 is inserted into a steel pipe 52 of the sheet pile structure 51, and a nut member 19 is screwed through a washer 18. Meanwhile, the other axial end of the existing tie rod 4 is also formed into a male thread portion 15, and this male thread portion 15 is screwed into one axial end of the turnbuckle 5. The other axial end of the turnbuckle 5 is screwed into the other existing tie rod 4A. Then, by rotating the turnbuckle 5, a predetermined tension is applied between the sheet pile structure 51 (steel sheet pile or steel pipe sheet pile) and the bracing work 53 by the existing tie rods 4, 4A.

[0019] 1 and 2, the branch joint 8 is attached to the other existing tie rod 4A at a position close to the turnbuckle 5. More specifically, the branch joint 8 is attached so that the longitudinal end face of the branch joint 8 abuts against the axial end face of the turnbuckle 5. The branch joint 8 is configured to have a block shape with an external shape of a substantially rectangular parallelepiped. In the front view shown in FIG. 2(a), the branch joint 8 includes an attachment body part 23 having an insertion hole 22 through which the other existing tie rod 4A is inserted, and a pair of clamping plate parts 24, 24 that are integrally suspended downward from the attachment body part 23 and spaced apart along the width direction. In the front view shown in FIG. 2(a), the branch joint 8 is configured to be split into two parts from the center position in the width direction. That is, the branch joint 8 is configured by integrally joining a pair of branch split joints 8A, 8A.

[0020] The branched split joint 8A includes a split mounting body 23A having an elongated rectangular parallelepiped shape and a clamping plate 24 that is vertically disposed downward from the other end surface in the width direction of the split mounting body 23A. A mounting hole 26 penetrates the upper part of the split mounting body 23A along the width direction. A plurality of mounting holes 26, 26 are formed at intervals along the longitudinal direction. In this embodiment, two mounting holes 26, 26 are formed. A semicircular recess 30 is formed along the entire area of ​​the split mounting body 23A along one end surface in the width direction. The semicircular recess 30 is formed below each mounting hole 26. The clamping plate 24 is vertically disposed downward integrally from the other end surface in the width direction of the split mounting body 23A. A connecting hole 28 penetrates the clamping plate 24 below each mounting hole 26 of the split mounting body 23A and at the same position along the longitudinal direction as one mounting hole 26. A mounting ring portion 32 is provided on the surface of the clamping plate portion 24 facing the divided mounting body portion 23A, and protrudes around the connecting hole 28. A notch portion 29 is formed in the clamping plate portion 24 at a portion opposite the connecting hole 28, extending in an oblique direction.

[0021] When the pair of branched split joints 8A, 8A are integrally joined to form the branch joint 8, the widthwise end faces of the split mounting main bodies 23A, 23A are abutted against each other, and the positions of the mounting holes 26, 26 of the split mounting main bodies 23A, 23A are aligned, and the positions of the semicircular recesses 30, 30 of the split mounting main bodies 23A, 23A are aligned. Then, mounting bolts (not shown) are inserted into the mounting holes 26, 26 of the split mounting main bodies 23A, 23A to fix them. Then, the mounting main body 23 of the branch joint 8 is formed with an insertion hole 22 (a pair of semicircular recesses 30, 30) through which another existing tie rod 4A is inserted, and a pair of clamping plate parts 24, 24 are provided that are integrally suspended downward from the mounting main body 23 and spaced apart along the widthwise direction, and the connection holes 28, 28 of the pair of clamping plate parts 24, 24 are arranged in opposing positions.

[0022] 2, in the branch joint 8, it is better to set the distance L in the up-down direction between the insertion hole 22 and the connection hole 28 to a minimum (for example, 180 mm in this embodiment). This allows the axial end of the existing tie rod 4 and the split tie rod 9C of the tension bearing tie rod 9 to be close to each other, suppressing the bending moment and shear force on the existing tie rod 4 caused by eccentricity, and allowing the tension of the existing tie rod 4 to be safely borne by the tension bearing tie rod 9.

[0023] Referring to FIG. 1, the tension-bearing tie rod 9 is configured by connecting a plurality of split tie rods 9A, 9B, and 9C in series. The outer diameter of each split tie rod 9A, 9B, and 9C is larger than the outer diameter of the existing tie rod 4. The outer diameter of each split tie rod 9A, 9B, and 9C may be the same as the outer diameter of the existing tie rod 4. In this embodiment, there are three split tie rods 9A, 9B, and 9C, with one split tie rod 9B being the longest and two split tie rods 9A and 9C being approximately the same length. Referring to FIG. 3, one axial end of each split tie rod 9A, 9B, and 9C is formed in a flat plate portion 13, and a through hole 14 is formed in the flat plate portion 13. A male thread portion 15 is formed in the other axial end of each split tie rod 9A, 9B, and 9C.

[0024] 1, split tie rods 9B, 9C arranged adjacent to the branch joint 8 side are connected via a turnbuckle 5. Split tie rods 9A, 9B arranged adjacent to the sheet pile structure 51 side are connected via a ring joint 6. Of the three split tie rods 9A, 9B, 9C, the split tie rod 9C on the branch joint 8 side has its flat plate portion 13 arranged between the mounting annular portions 32, 32 of the pair of clamping plate portions 24, 24 of the branch joint 8, and is fixed by inserting a mounting bolt 35 through the pair of connecting holes 28, 28 and the through hole 14. As a result, the tension-bearing tie rod 9 is connected to the branch joint 8 so as to be rotatable about the mounting bolt 35, i.e., the connecting hole 28. On the other hand, of the three split tie rods 9A, 9B, 9C, the split tie rod 9A on the sheet pile structure 51 side has its male thread portion 15 inserted into the steel pipe 52 of the sheet pile structure 51, and is fixed by screwing a nut member 19 onto the male thread portion 15 via a pair of upper and lower flaps 37, 37 (including two washers 18, 18). The inclination angle of the tension-bearing tie rod 9 with respect to the horizontal direction is slightly larger than the inclination angle of the existing tie rod 4 with respect to the horizontal direction.

[0025] Next, a tie rod installation method according to the first embodiment will be described based on Figures 4 to 9, and also with reference to Figures 1 to 3 as appropriate. The tie rod installation method according to the first embodiment replaces an existing tie rod 4 connected to a sheet pile structure 51 with a new tie rod 40, thereby restoring its function. In detail, the tie rod construction method of the first embodiment includes a preparation step of preparing a tension-bearing tie rod 9 for bearing the tension of the existing tie rod 4, and a branch joint 8 for connecting the tension-bearing tie rod 9 to the existing tie rod 4, an excavation step of excavating the ground on the back side of the wharf 50, an installation step of attaching the branch joint 8 to another existing tie rod 4A connected to the existing tie rod 4 via a turnbuckle 5, a connection step of connecting the branch joint 8 to a sheet pile structure 51 (one of the structures) with the tension-bearing tie rod 9, a replacement step of removing the existing tie rod 4 from the turnbuckle 5 and the sheet pile structure 51 and replacing it with a new tie rod 40, and then removing the branch joint 8 and the tension-bearing tie rod 9, and an burying step of burying the new tie rod 40 in the ground.

[0026] That is, first, in a preparation step, the tension-bearing tie rod 9 (multiple split tie rods 9A, 9B, 9C) and the branch joint 8 are prepared. The specific configurations of the tension-bearing tie rod 9 and the branch joint 8 have been described above, so a description thereof will be omitted here. Next, with reference to FIG. 4, a ground excavation step is performed. In this ground excavation step, the ground on the rear side of the quay wall 50 is excavated until the existing tie rod 4 and a part of another existing tie rod 4A connected to the existing tie rod 4 via the turnbuckle 5 are exposed.

[0027] Next, referring to Figs. 1 to 3 and 5, an installation step is performed. In this installation step, the branch joint 8 is installed at a location close to the turnbuckle 5 of the other existing tie rod 4A. Specifically, in the installation step, the branch joint 8 is divided into a pair of branch split joints 8A, 8A. Next, the split mounting body parts 23A, 23A of the pair of branch split joints 8A, 8A are abutted with one end surface in the width direction so as to sandwich the other existing tie rod 4A in the semicircular recesses 30, 30 of the split mounting body parts 23A, 23A of the pair of branch split joints 8A, 8A, and the positions of the mounting holes 26, 26 of the split mounting body parts 23A, 23A are matched. Next, a mounting bolt is inserted and fixed into each mounting hole 26 of each split mounting body part 23A. This allows the branch joint 8 to be installed to the other existing tie rod 4A. At this time, as described above, the longitudinal end surface of the branch joint 8 is abutted against the axial end surface of the turnbuckle 5.

[0028] Next, referring to Fig. 1 to Fig. 3 and Fig. 5, a connecting step is performed. In this connecting step, the flat plate portion 13 of the tension-bearing tie rod 9, i.e., the split tie rod 9C on the branch joint 8 side among the three split tie rods 9A, 9B, 9C, is placed between the pair of clamping plate portions 24, 24 of the branch joint 8. Then, the mounting bolt 35 is inserted through the connecting holes 28, 28 of the pair of clamping plate portions 24, 24 and the through hole 14 of the flat plate portion 13 to fix the split tie rods. Then, the male thread portion 15 of the split tie rod 9A on the sheet pile structure 51 side among the three split tie rods 9A, 9B, 9C is inserted into the steel pipe 52 of the sheet pile structure 51, and the nut member 19 is screwed and fixed to the male thread portion 15 via a pair of upper and lower flaps 37, 37 (including two washers 18, 18).

[0029] At this time, as described above, the inclination angle of the tension-bearing tie rod 9 with respect to the horizontal direction becomes slightly larger than the inclination angle of the existing tie rod 4 with respect to the horizontal direction. Next, a predetermined tension is generated in the tension-bearing tie rod 9 by rotating the turnbuckle 5 between the split tie rod 9B and the split tie rod 9C. Then, the tension-bearing tie rod 9 is connected below the existing tie rod 4 via the branch joint 8, so that the tension of the existing tie rod 4 can be borne by the tension-bearing tie rod 9.

[0030] Next, referring to Figs. 1 to 3 and 6, a replacement step is performed. In the replacement step, first, the existing tie rod 4 is removed from the sheet pile structure 51 and the turnbuckle 5. Next, referring to Fig. 7, a new tie rod 40 is attached to that position. The new tie rod 40 is configured by connecting a plurality of new split tie rods 40A, 40B in series. In this embodiment, the new split tie rods 40A, 40B are two, and are configured by a long new split tie rod 40A and a short new split tie rod 40B. Referring to Fig. 3, each of the new split tie rods 40A, 40B has the same configuration as the split tie rods 9A, 9B, 9C of the tension-bearing tie rod 9, and one axial end of each of the new split tie rods is formed in a flat plate portion 13, and a through hole 14 is formed in the flat plate portion 13. A male thread portion 15 is formed in the other axial end of each of the new split tie rods 40A, 40B. The new tie rod 40 is configured by bridging the ring joint 6 between the through holes 14, 14 of the respective flat plate portions 13, 13 of the new split tie rods 40A, 40B.

[0031] The male threaded portion 15 of one of the newly installed split tie rods 40B is inserted into the steel pipe 52 of the sheet pile structure 51, and the nut member 19 is screwed and fixed to the male threaded portion 15 via a pair of upper and lower flaps 37, 37 (including two washers 18, 18). The male threaded portion 15 of the other newly installed split tie rod is screwed and fixed to the turnbuckle 5. Then, by rotating the turnbuckle 5, a predetermined tension is applied between the sheet pile structure 51 (steel sheet pile or steel pipe sheet pile) and the bracing work 53 by the newly installed tie rod 40 and the existing tie rod 4A. Next, referring to FIG. 8, the tension-bearing tie rod 9 is removed from the branch joint 8 and the sheet pile structure 51, the branch joint 8 is removed from the other existing tie rod 4A, and the tension-bearing tie rod 9 and the branch joint 8 are removed. Next, referring to FIG. 9, the embedding step is performed. In this embedding step, the soil excavated in the above-mentioned ground excavation step is backfilled and the new tie rod 40 is embedded.

[0032] Next, a tie rod construction method according to the second embodiment will be described. The tie rod construction method according to the second embodiment is to bury the tie rod structure 1 according to the present embodiment, including the existing tie rod 4 connected to the sheet pile structure 51, the tension bearing tie rod 9, and the branch joint 8, and restore its function. In detail, the tie rod construction method according to the second embodiment includes a preparation step of preparing the tension bearing tie rod 9 for bearing the tension of the existing tie rod 4 and the branch joint 8 for connecting the tension bearing tie rod 9 to the existing tie rod 4, a ground excavation step of excavating the ground on the back side of the quay wall 50, an attachment step of attaching the branch joint 8 to another existing tie rod 4A connected to the existing tie rod 4 via the turnbuckle 5, a connection step of connecting the branch joint 8 to the sheet pile structure 51 with the tension bearing tie rod 9, and an embedding step of embedding the existing tie rod 4, the tension bearing tie rod 9, and the branch joint 8 in the ground.

[0033] In other words, in the tie rod construction method of the second embodiment, the tie rod structure 1 of this embodiment, which includes the existing tie rod 4, the tension-bearing tie rod 9 and the branch joint 8, is buried directly in the ground without performing the replacement step of replacing the existing tie rod 4 with a newly installed tie rod 40, which is adopted in the tie rod construction method of the first embodiment.

[0034] In the tie rod construction method according to the first and second embodiments described above, at least the tension-bearing tie rod 9 for bearing the tension of the existing tie rod 4 and the branch joint 8 for connecting the tension-bearing tie rod 9 to the existing tie rod 4 are prepared and used as a preparation step. Then, while the tension of the damaged existing tie rod 4 is being borne by the tension-bearing tie rod 9, the existing tie rod 4 can be replaced with the new tie rod 40, or the existing tie rod 4 can be buried together while the tension of the existing tie rod 4 is being borne by the tension-bearing tie rod 9, and the function of the existing tie rod 4 can be restored without releasing the tension of the existing tie rod 4. As a result, there is no need to take safety measures when releasing the tension of the existing tie rod 4, that is, measures to prevent the sheet pile structure 51 from tilting toward the sea, and the construction can be made small-scale, which leads to a reduction in construction costs.

[0035] Furthermore, in the tie rod installation method according to the first embodiment, particularly in the installation step and the connection step, the tension of the existing tie rod 4 is temporarily borne by the tension-bearing tie rod 9, and during that time, the existing tie rod 4 is replaced with the new tie rod 40 in the replacement step, thereby restoring its function. In this way, the function of the existing tie rod 4 can be restored without releasing the tension of the existing tie rod 4, and the same effect as described above can be achieved.

[0036] Furthermore, in the tie rod construction method according to the second embodiment, in particular, the attachment step and the connection step connect the tension-bearing tie rod 9 to the damaged existing tie rod 4 via the branch joint 8, and the tension of the existing tie rod 4 is made to be borne by the tension-bearing tie rod 9, and then the burying step buries the existing tie rod 4, the branch joint 8, and the tension-bearing tie rod 9 in the ground, thereby restoring its function. In this way, since the function of the existing tie rod 4 can be restored without releasing the tension of the existing tie rod 4, the same effect as described above can be achieved. In addition, in the tie rod construction method according to the second embodiment, compared to the tie rod construction method according to the first embodiment, the replacement step of replacing the existing tie rod 4 with the new tie rod 40 is not performed, so that the construction period can be shortened and the construction cost can be further reduced.

[0037] Furthermore, since the tie rod structure 1 according to this embodiment includes the tension-bearing tie rod 9 connected to another existing tie rod 4A via a branch joint 8, the tension of the existing tie rod 4 can be borne by the tension-bearing tie rod 9 without releasing the tension of the damaged existing tie rod 4, thereby restoring its function. This eliminates the need for safety measures when releasing the tension of the existing tie rod 4, i.e., measures to prevent the sheet pile structure 51 from tilting toward the sea, and the construction can be made small-scale, leading to reduction in construction costs.

[0038] Furthermore, in the tie rod structure 1 of this embodiment, the tension-bearing tie rod 9 is freely rotatable around the connecting hole 28 of the branch joint 8 (the base end of the tension-bearing tie rod 9), so that the tip of the tension-bearing tie rod 9 can be easily connected to the sheet pile structure 51.

[0039] Furthermore, in the tie rod structure 1 according to this embodiment, the branch joint 8 is configured to be separable, so that the branch joint 8 can be easily connected to the outer periphery of another existing tie rod 4A. [Explanation of symbols]

[0040] 1 tie rod structure, 4 existing tie rod, 4A other existing tie rod, 5 turnbuckle, 8 branch joint, 9 tension-bearing tie rod, 22 insertion hole, 28 connection hole, 40 new tie rod, 50 wharf, 51 sheet pile structure (one of the structures), 52 bracing (structure)

Claims

1. A method of installing a tie rod that extends between a pair of spaced apart structures and stabilizes one of the structures by tensioning the tie rod, comprising the steps of: A tension-bearing tie rod for bearing the tension of the existing tie rod; A branch joint for connecting the tension-bearing tie rod to the existing tie rod; A tie rod installation method characterized by using at least one of the following.

2. An installation step of installing the branch joint to another existing tie rod connected to the existing tie rod via a turnbuckle; a connecting step of connecting the branch joint and the one structure by the tension-bearing tie rod; A replacement step of removing the existing tie rod from the turnbuckle and the one of the structures and replacing it with a new tie rod, and then removing the branch joint and the tension-bearing tie rod; The method for installing a tie rod according to claim 1, further comprising the steps of:

3. An installation step of installing the branch joint to another existing tie rod connected to the existing tie rod via a turnbuckle; a connecting step of connecting the branch joint and the one structure by the tension-bearing tie rod; An embedding step of embedding the existing tie rod, the branch joint, and the tension-bearing tie rod in the ground; The method for installing a tie rod according to claim 1, further comprising:

4. 1. A tie rod structure extending between a pair of spaced apart structures and stabilizing one of said structures by tension therein, A tie rod structure comprising a tension-bearing tie rod connected to an existing tie rod via a branch joint.

5. The branch joint is An insertion hole through which the existing tie rod is inserted; A connection hole that connects the tension-bearing tie rod so as to be rotatable about its axial end portion; The tie rod structure according to claim 4, further comprising:

6. The tie rod structure according to claim 5 , wherein the branch joint is configured to be separable.

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