PC floor slab replacing method

Abstract

To provide a PC floor slab replacing method capable of replacing only a PC floor slab needed to be replaced with a new PC floor slab.SOLUTION: This PC floor slab replacing method for replacing an existing PC floor slab with a new PC floor slab comprises: a removal step of removing the existing PC floor slab installed between a second floor slab and a third floor slab; a connection step of installing a first floor slab, which is a precast floor slab, at a location where the existing PC floor slab has been removed, connecting one end of a first tendon penetrating the first floor slab to a second tendon penetrating the second floor slab, and connecting the other end of the first tendon to a third tendon penetrating the third floor slab; and a tensioning step of tensioning the first tendon.SELECTED DRAWING: Figure 21

Description

[Technical field]

[0001] The present invention relates to a method for replacing a PC deck slab. [Background technology]

[0002] In recent years, in renewal works for expressways, etc., existing bridge decks are being renewed with precast decks made of reinforced concrete manufactured in advance at factories, etc., because this method can significantly shorten the period of road closures. In addition, precast PC decks, in which prestress is introduced in advance using tendons such as PC steel and continuous fiber reinforcement, are becoming common, because they can improve durability and reduce the dead load by reducing the deck thickness.

[0003] As shown in FIG. 33, in the conventional PC deck 90, fixing devices 95 are provided at both ends of the tendons 92 that penetrate a plurality of concrete skeletons 91 to fix the tendons 92 to the skeletons 91. In addition, the skeletons 91 on which the fixing devices 95 are provided are also provided with fixing devices 98 for other tendons 97 different from the tendons 92 on which the fixing devices 95 are provided. For this reason, when replacing a damaged existing PC deck 90, it is necessary to replace not only the damaged portion but also the entire area between the fixing devices 95, 95. And, when removing the fixing device 95, it is necessary to remove the skeletons 91 on which the fixing devices 95 and 98 are provided. For this reason, healthy PC decks that do not need to be replaced are also removed. Therefore, in the conventional PC deck joining method, there was a situation where only the PC decks that need to be replaced could not be replaced with a new PC deck.

[0004] Conventionally, Patent Document 1 discloses a technique for re-anchoring PC steel members in a narrow working space such as under a girder during bridge repair work, without providing an intermediate anchoring portion for an existing PC structure.

[0005] The re-anchoring method of Patent Document 1 includes an exposure step in which, in an existing PC structure in which compressive force is applied to the main body portion by PC steel members consisting of multiple tensioned steel wires, the concrete near the position where the PC steel members will be cut is chipped away and the existing attachment portion is removed to expose a pre-calculated length of PC steel members, an installation step in which a support plate base and a support plate supported by the support plate are installed on the end face of the exposed PC steel members to expand the spacing between the multiple steel wires, and a tensioning and fixing step in which a single jack is installed in the space formed by the installation step to tension and fix each PC steel member one by one.

[0006] However, the technology disclosed in Patent Document 1 is only for re-anchoring existing PC steel members, and is not for replacing existing PC decks with new PC decks. For this reason, there is a strong demand for technology that can replace only the PC decks that need to be replaced with new PC decks. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2015-140555 A Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, the present invention has been devised in consideration of the above-mentioned circumstances, and its purpose is to provide a method for replacing PC deck slabs that makes it possible to replace only the PC deck slabs that need to be replaced with new PC deck slabs. [Means for solving the problem]

[0009] The PC deck replacement method of the present invention is a PC deck replacement method for replacing an existing PC deck with a new PC deck, and is characterized in that it includes a removal process for removing the existing PC deck installed between the second deck and the third deck, a connection process for installing a first deck which is a precast deck at the location from which the existing PC deck was removed, connecting one end of a first tendon that penetrates the first deck to a second tendon that penetrates the second deck and connecting the other end of the first tendon to a third tendon that penetrates the third deck, and a tensioning process for tensioning the first tendon. Effect of the Invention

[0010] According to the present invention, it is possible to replace only the PC deck slab that needs to be replaced with a new PC deck slab. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view showing a first floor slab used in a joining method for precast PC floor slabs according to the first embodiment. [Diagram 2] FIG. 2 shows a flowchart of the joining method for precast PC floor slabs according to the first embodiment. [Diagram 3] Figure 3(a) is a cross-sectional view showing the state in which the first connecting device is installed in the first deck installation process, and Figure 3(b) is a cross-sectional view showing the state in which the first fixing device is installed on the first tendon in the first deck installation process. [Figure 4] Figure 4(a) is a cross-sectional view showing the first deck slab installed between the second and third deck slabs in the first deck slab installation process, and Figure 4(b) is a cross-sectional view showing the first deck slab connected to the second deck slab in the second deck slab connection process. [Diagram 5] Figure 5(a) is a cross-sectional view showing the state in which the connection outer sleeve of the first connector is installed on the first tendon in the third deck connection process, and Figure 5(b) is a cross-sectional view showing the state in which the connection bolt is connected in the third deck connection process. [Figure 6]Figure 6(a) is a cross-sectional view showing the state in which the second fixing device is installed on the other end of the first tension member in the third deck connection process, and Figure 6(b) is a cross-sectional view showing the state in which the second fixing device and the second connecting device are connected in the third deck connection process. [Figure 7] Figure 7(a) is a cross-sectional view showing the state in which a screw bushing and a tensioning sleeve are installed on the second fixing device during the tensioning process, and Figure 7(b) is a cross-sectional view showing the state in which a U-shaped chair and a curved chair are installed during the tensioning process. [Figure 8] Figure 8(a) is a cross-sectional view showing the state in which the U-shaped chair and the curved chair are connected with a bolt during the tensioning process, and Figure 8(b) is a plan view mainly showing the other end of the first tension member in Figure 8(a). [Figure 9] FIG. 9(a) is a cross-sectional view showing the state in which a straight chair is installed in the tensioning process, and FIG. 9(b) is a cross-sectional view showing the state in which the straight chair is connected to the curved chair in the tensioning process. [Figure 10] FIG. 10 is a cross-sectional view showing a state in which the first tendon is tensioned by the tensioning device in the tensioning step. [Figure 11] FIG. 11(a) is a cross-sectional view showing the first deck after the tensioning process is completed, and FIG. 11(b) is a plan view mainly showing the other end of the first tension member in FIG. 11(a). [Figure 12] FIG. 12 is a diagram for explaining the precast plate installation process. [Figure 13] FIG. 13 is a cross-sectional view showing a first floor slab, a second floor slab, and a third floor slab used in the joining method for precast PC floor slabs according to the second embodiment. [Figure 14] FIG. 14 shows a flowchart of the joining method for precast PC floor slabs according to the second embodiment. [Figure 15] Figure 15(a) is a cross-sectional view showing the first deck after completion of the first deck installation process and the second deck connection process, and Figure 15(b) is a cross-sectional view showing the state of installing the first sleeve and the second sleeve of the second connector in the third deck connection process. [Figure 16]Figure 16(a) is a cross-sectional view showing the state in which the first sleeve and the second sleeve are connected with a plug in the third deck connection process, and Figure 16(b) is a cross-sectional view showing the state in which the first tension member is tensioned by the plug in the tensioning process. [Figure 17] FIG. 17 shows a flowchart of a joining method for precast PC floor slabs according to the third embodiment. [Figure 18] Figure 18(a) is a cross-sectional view showing the second deck at the start of the first deck installation process, and Figure 18(b) is a cross-sectional view showing the state after the first connector has been installed on the third fixing device in the first deck installation process. [Figure 19] Figure 19(a) is a cross-sectional view showing the first deck installed adjacent to the second deck in the first deck installation process, and Figure 19(b) is a cross-sectional view showing the state in which the first tendon is connected to the second deck in the second deck connection process. [Figure 20] Figure 20(a) is a cross-sectional view showing the third deck installed adjacent to the first deck in the third deck installation process, and Figure 20(b) is a cross-sectional view showing the state after the second tendon is installed on the third deck in the third deck connection process. [Figure 21] Figure 21(a) is a cross-sectional view showing the state in which the first tendon is connected to the third deck slab in the third deck connection process, and Figure 21(b) is a cross-sectional view showing the state in which the first tendon and the third tendon are tensioned in the tensioning process. [Figure 22] FIG. 22 shows a flowchart of the PC deck replacement method according to the first embodiment. [Figure 23] Figure 23(a) is a cross-sectional view showing the state in which the connection of the existing first tendon is released during the removal process, and Figure 23(b) is a cross-sectional view showing the state in which the existing first deck slab has been removed during the removal process. [Figure 24] FIG. 24 is a cross-sectional view showing a first floor slab used in a joining method for precast PC floor slabs according to the fourth embodiment. [Diagram 25] FIG. 25 shows a flowchart of a PC deck replacement method according to the second embodiment. [Figure 26]FIG. 26(a) is a cross-sectional view showing the first deck at the start of the removal process, and FIG. 26(b) is a cross-sectional view showing the existing PC deck that has been chipped in the chipping process. [Figure 27] Figure 27(a) is a cross-sectional view showing the state in which the first retaining device and the second retaining device are installed on the existing tendon during the retaining process, and Figure 27(b) is a cross-sectional view showing the existing tendon in a state in which the tensioning force is maintained during the retaining process. [Figure 28] Figure 28(a) is a cross-sectional view showing the state in which the first retaining device and the second retaining device are held on the existing tendon in the retaining process, and Figure 28(b) is a cross-sectional view showing the state in which the existing tendon cut in the cutting process is held by the retaining devices. [Figure 29] Figure 29(a) is a cross-sectional view showing the state after the first deck slab has been installed in the first deck slab installation process, and Figure 29(b) is a cross-sectional view showing the state after the first tendon has been connected to the second deck slab in the second deck slab connection process and after the first tendon has been connected to the third deck slab in the third deck slab connection process. [Diagram 30] Figure 30(a) is a cross-sectional view showing the state in which the first tensioning member and the first tensioning member are tensioned during the tensioning process, and Figure 30(b) is a cross-sectional view showing the state in which the first retaining device and the second retaining device have been removed during the tensioning process. [Diagram 31] FIG. 31 shows a flowchart of a PC deck replacement method according to the third embodiment. [Diagram 32] FIG. 32(a) is a cross-sectional view showing the state in which the first tendon is released in the removal process, and FIG. 32(b) is a cross-sectional view showing the state in which the first deck slab has been removed in the removal process. [Diagram 33] FIG. 33 is a cross-sectional view showing a conventional PC deck slab. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a method for joining precast PC decks and a method for replacing PC decks according to an embodiment will be described in detail with reference to the drawings. In each drawing, the vertical direction is the vertical direction Z, one planar direction that intersects with the vertical direction Z, for example, perpendicular to it, is the extension direction X, and another planar direction that intersects with the vertical direction Z and the extension direction X, for example, perpendicular to it, is the width direction Y. One side of the extension direction X is the first extension direction X1, and the other side is the second extension direction X2. In each drawing, common parts are given common reference symbols, and duplicated explanations are omitted.

[0013] <First embodiment: Joining method for precast PC floor slabs> First, a first floor slab 10 used in the joining method for precast PC floor slabs according to the first embodiment will be described.

[0014] As shown in FIG. 1 , the first deck 10 is a precast deck, and is provided between the second deck 20 and the third deck 30. The first deck 10 has a T-shaped cross section along the extension direction X, and has a first tendon 12 for applying prestress. The first deck 10 has a main body 11 through which the first tendon 12 passes, and extensions 18 and 19 which are the remaining portions obtained by cutting out both sides of the main body 11 in the extension direction X. The main body 11 is separated from the second deck 20 and the third deck 30.

[0015] The extension portion 18 is formed on the second deck 20 side of the upper end of the main body 11. A precast plate 71 is installed on the first deck 10 on the opposite side of the extension portion 18, with one end 13 of the first tendon 12 in between. The precast plate 71 is a plate material extending from the end face of the main body 11 in the first extension direction X1 to the second deck 20, and is installed at the lower end of the main body 11. A lateral tightening member 73 extending in the width direction Y is arranged inside the precast plate 71.

[0016] The extension portion 19 is formed on the third deck 30 side of the upper end of the main body 11. A precast plate 72 is installed on the first deck 10 on the opposite side of the extension portion 19, with the other end 14 of the first tendon 12 in between. The precast plate 72 is a plate material extending from the end face of the main body 11 in the second extension direction X2 to the third deck 30, and is installed at the lower end of the main body 11. A lateral tightening member 74 extending in the width direction Y is arranged inside the precast plate 72.

[0017] The first tendon 12 is made of, for example, a PC steel strand and extends linearly in the extension direction X. A sheath tube 17 is provided around the first tendon 12, and the sheath tube 17 is filled with grout material. Note that the first tendon 12 can also use a continuous fiber reinforcing material such as carbon fiber or resin fiber as the tendon.

[0018] The first tendon 12 has one end 13 which is an end on the first extension direction X1 side and the other end 14 which is an end on the second extension direction X2 side. The one end 13 of the first tendon 12 and the other end 14 of the first tendon 12 protrude from the main body 11 of the first deck 10.

[0019] A first fixing device 150 is fixed to one end 13 of the first tendon 12. The first fixing device 150 has a sleeve 151, a wedge 152, a retaining washer 153, and a bolt 154.

[0020] The sleeve 151 is provided around one end 13 of the first tendon 12 and is formed in a cylindrical shape. The inner surface of the sleeve 151 is formed as an inclined surface, and a wedge 152 is provided on the inside. The wedge 152 is disposed inside the sleeve 151, and has a wedge-shaped outer shape. The retaining washer 153 is provided on the end surface of the wedge 152, and a bolt 154 is passed through the retaining washer 153. The passed bolt 154 is screwed into the sleeve 151. In this way, the first fixing device 150 is fixed to the first tendon 12.

[0021] One end 13 of the first tendon 12 is connected to the second tendon 22 by a first connector 155. The first connector 155 connects the first fixing device 150 and a third fixing device 25, which will be described later. The first connector 155 is, for example, a tubular outer sleeve, and is connected to a sleeve 151 of the first fixing device 150.

[0022] A second fixing tool 160 is fixed to the other end 14 of the first tendon 12. The second fixing tool 160 has a sleeve 161, a wedge 162, and a fixing member 163.

[0023] The sleeve 161 is provided around the first tendon 12 and is formed in a cylindrical shape. The inner surface of the sleeve 161 is formed with an inclined surface, and a wedge 162 is provided on the inside. The wedge 162 is disposed inside the sleeve 161 and has a wedge-shaped outer shape. The fixing member 163 is, for example, a ring nut, and is provided around the sleeve 161. The second fixing device 160 is fixed to the first tendon 12 by rotating the fixing member 163 using a tensioning device.

[0024] The other end 14 of the first tendon 12 is connected to the third tendon 32 by a second connector 165. The second connector 165 connects the second fixing device 160 to a fourth fixing device 35, which will be described later. The second connector 165 has a threaded bushing 166, a connection outer sleeve 167, and a connection bolt 168.

[0025] The threaded bushing 166 has the sleeve 351 of the fourth fixing device 35 connected to its outer surface, and the connecting bolt 168 connected to its inner surface. The connecting outer sleeve 167 is formed in a box shape, and has the second fixing device 160 provided at one end and the fourth fixing device 35 provided at the other end. The connecting bolt 168 connects the threaded bushing 166 and the connecting outer sleeve 167.

[0026] The second deck 20 is a PC deck and has a second tendon 22 for applying prestress. The second tendon 22 is a tendon separate from the first tendon 12, and may be, for example, a PC steel strand. The second tendon 22 may also be made of continuous fiber reinforcement such as carbon fiber or resin fiber. A third fixing device 25 is provided at the end of the second tendon 22. The second deck 20 may be a precast deck.

[0027] The third fixing device 25 fixes the second tendon 22 to the second deck 20. The third fixing device 25 is connected to the first fixing device 150 by the first connecting device 155. The third fixing device 25 has a sleeve 251 and a wedge 252.

[0028] The sleeve 251 is provided around the second tendon 22 and is formed in a cylindrical shape. The inner surface of the sleeve 251 is formed as an inclined surface, and a wedge 252 is provided on the inside. The wedge 252 is disposed on the inside of the sleeve 251, and is formed with a wedge-shaped outer shape.

[0029] The third deck 30 is a PC deck and has a third tendon 32 for applying prestress. The third tendon 32 is a tendon different from the first tendon 12, and for example, a PC steel strand is used. The third tendon 32 can also be made of continuous fiber reinforcement such as carbon fiber or resin fiber. A fourth anchor 35 is provided at the end of the third tendon 32. The third deck 30 may be a precast deck.

[0030] The fourth fixing device 35 fixes the third tendon 32 to the third deck 30. The fourth fixing device 35 is connected to the second fixing device 160 by the second connector 165. The fourth fixing device 35 has a sleeve 351, a wedge 352, and an fixing member 353.

[0031] The sleeve 351 is provided around the third tendon 32 and is formed in a cylindrical shape. The inner surface of the sleeve 351 is formed with an inclined surface, and a wedge 352 is provided on the inside. The sleeve 351 is provided with a threaded bushing 166 on the inner surface of one end, and an anchoring member 353 is provided on the outer surface of the other end. The wedge 352 is disposed inside the sleeve 351, and is formed with a wedge-shaped outer shape. The anchoring member 353 is a ring nut, a shim, or the like, and comes into contact with the third deck 30.

[0032] <Precast PC floor slab joining method S100> Next, a procedure of the joining method S100 for precast PC floor slabs according to the first embodiment will be described. The joining method S100 for precast PC floor slabs is to join the first floor slab 10, which is a precast floor slab, by applying prestress.

[0033] As shown in Figure 2, the method S100 for joining precast PC deck slabs includes a connection process S110 for connecting one end 13 of a first tension member 12 passing through a first deck 10, which is a precast deck, to a second tension member 22 passing through a second deck 20, and for connecting the other end 14 of the first tension member 12 of the first deck 10 to a third tension member 32 passing through a third deck 30 arranged on the opposite side of the second deck 20 across the first deck 10, and a tensioning process S150 for tensioning the first tension member 12.

[0034] <Connection step S110> The connection process S110 includes a first deck installation process S120 in which the first deck 10 is installed between the second deck 20 and the third deck 30, a second deck connection process S130 in which one end 13 of the first tension member 12 and the second tension member 22 of the second deck 20 are connected using a first connector 155, and a third deck connection process S140 in which the other end 14 of the first tension member 12 and the third tension member 32 of the third deck 30 are connected using a second connector 165.

[0035] <1st floor slab installation process S120> As shown in Fig. 3(a), the first deck installation process S120 starts with the second deck 20 having been installed. The second deck 20 is prestressed by the second tendon 22, and the third fastener 25 is fixed to the end of the second tendon 22. After the second deck 20 is prestressed, the portion of the second tendon 22 that protrudes to the opposite side of the second deck 20 across the third fastener 25 is cut to a predetermined length.

[0036] At this time, in the first deck installation process S120, the third deck 30 is provided spaced apart from the second deck 20 in the extension direction X. The third deck 30 is prestressed by a third tendon 32, and a fourth fixing device 35 is fixed to an end of the third tendon 32. After prestressing, the portion of the third tendon 32 that protrudes to the opposite side of the third deck 30 across the fourth fixing device 35 is cut to a predetermined length.

[0037] In the first deck slab installation process S120, the first connector 155 is installed to the third fixing device 25 provided on the second tendon 22.

[0038] Next, as shown in Figure 3(b), in the first deck installation process S120, the first tension member 12 is inserted through the main body 11 of the first deck slab 10, and a first fixing device 150 is installed at one end 13 of the inserted first tension member 12.

[0039] Next, as shown in FIG. 4(a), in the first floor slab installation step S120, the first floor slab 10 is installed between the second floor slab 20 and the third floor slab 30 by being suspended by a crane or the like.

[0040] <Second floor slab connection process S130> Next, as shown in Figure 4(b), in the second deck connection process S130, the first connector 155 is connected to the first fixing device 150 installed on one end 13 of the first tension member 12, thereby connecting one end 13 of the first tension member 12 to the second tension member 22 of the second deck 20.

[0041] <Third floor slab connection process S140> Next, in the third deck slab connecting process S140, the screw bushing 166 is connected to the sleeve 351 of the fourth fixing device 35.

[0042] Next, as shown in FIG. 5( a ), in the third deck slab connecting step S140, the first tendon 12 is inserted into one end of the connection outer sleeve 167 .

[0043] Next, as shown in FIG. 5( b ), in the third deck slab connecting step S140 , the threaded bushing 166 and the connecting outer sleeve 167 are connected by a connecting bolt 168 .

[0044] Next, as shown in Fig. 6(a), in the third deck slab connecting process S140, a second fixing device 160 is installed on the other end 14 of the first tendon 12. In the third deck slab connecting process S140, a sleeve 161 provided with a fixing member 163 is installed around the other end 14 of the first tendon 12.

[0045] Next, as shown in Fig. 6(b), in the third deck slab connecting process S140, the second fixing device 160 installed on the other end 14 of the first tendon 12 is connected to the second connector 165. In the third deck slab connecting process S140, a sleeve 161 provided with a fixing member 163 is placed on one end of a connecting outer sleeve 167, and a wedge 162 is placed inside the sleeve 161. Thus, in the third deck slab connecting process S140, the second fixing device 160 and the fourth fixing device 35 are connected by the second connector 165.

[0046] <Tension process S150> Next, a tensioning process S150 is performed in which the linearly extended first tension member 12 is tensioned from a direction inclined to the extension direction of the first tension member 12 by a tensioning device 76 provided between the other end 14 of the first tension member 12 and the end of the third tension member 32.

[0047] In the tensioning process S150, a tensioning connector 78 is installed in the second fixing device 160. The tensioning connector 78 has a threaded bushing 781, a tensioning sleeve 782, a U-shaped chair 783, a curved chair 784, a straight chair 785, a fixing bolt 786, a pulling grip 787, a pulling strand 789, and a tensioning PC steel strand 788.

[0048] As shown in Fig. 7(a), in the tensioning process S150, a screw bushing 781 is inserted into the connection outer sleeve 167, and the inserted screw bushing 781 is connected to the sleeve 161. Then, in the tensioning process S150, a tensioning sleeve 782 is inserted into the connection outer sleeve 167, and the inserted tensioning sleeve 782 is connected to the screw bushing 781. In the tensioning process S150, a hole is provided in the tensioning sleeve 782 into which the other end 14 of the first tension member 12 is inserted, and the screw bushing 781 is screwed into a screw provided on the outer periphery of the sleeve 161 to fix it.

[0049] 7(b), in the tensioning process S150, a tensioning PC steel strand 788 is attached to a tensioning sleeve 782. A U-shaped chair 783 is installed in the tensioning sleeve 782, and a curved chair 784 is installed in the U-shaped chair 783.

[0050] As shown in Figures 8(a) and 8(b), in the tensioning step S150, the second fixing tool 160, the screw bushing 781, and the tensioning sleeve 782 are arranged inside a U-shaped chair 783 that is formed in a U-shape in a plan view. The curved chair 784 is for tensioning the first tension member 12 in a direction inclined at a predetermined angle, and is connected to the U-shaped chair 783 by a fixing bolt 786. This makes it possible to prevent the curved chair 784 from shifting relative to the U-shaped chair 783. Then, in the tensioning step S150, a pulling grip 787 is connected to the curved chair 784, and a pulling strand 789 is attached.

[0051] Next, as shown in FIG. 9(a), in the tensioning step S150, a straight chair 785 is inserted into a tensioning PC steel strand 788.

[0052] 9(b), in the tensioning process S150, a tensioning tool 75 is installed on the opposite side of the U-shaped chair 783 with the straight chair 785 in between, and the tensioning tool 75 is used to tension the pulling strand 789, pulling the straight chair 785 to the curved chair 784. Then, the straight chair 785 and the curved chair 784 are fastened together by a fixing bolt 786. The tensioning tool 75 is then removed from the straight chair 785.

[0053] Next, as shown in Fig. 10, in the tensioning step S150, the first tension member 12 is tensioned using a tensioning device 76. The tensioning device 76 has a tensioning jack 761 and a pulling head 762. The tensioning jack 761 is connected to a straight chair 785. The pulling head 762 is installed on the opposite side of the straight chair 785 with the tensioning jack 761 in between.

[0054] In the tensioning step S150, the first tendon 12 is tensioned in a direction inclined to its extension direction by using a tensioning device 76 installed on the opposite side of the U-shaped chair 783 across the straight chair 785. This allows the linearly extended first tendon 12 to be tensioned in a direction inclined to the extension direction of the first tendon 12.

[0055] In the tensioning step S150, the fixing member 163 is rotated when tensioning the first tendon 12, thereby fixing the second fixing device 160 to the first tendon 12. By tensioning the first tendon 12, as shown in Figures 11(a) and 11(b), the first tendon 12 stretches, the wedge 162 bites into the sleeve 161, and the connecting outer sleeve 167 stretches, so that a gap L is generated between the sleeve 161 and the connecting outer sleeve 167, and the second fixing device 160 is fixed to the first tendon 12.

[0056] The precast PC deck joining method S100 may further include a precast plate installation step S160 and a grout material filling step S170 after the tensioning step S150.

[0057] <Precast plate installation process S160> As shown in Figure 12, in the precast plate installation process S160, the first deck 10 has a main body 11 in which the first tension member 12 is arranged and spaced apart from the second deck 20 and the third deck 30, and extension portions 18, 19 which are the remaining portions obtained by cutting out both sides of the main body 11 in the extension direction X. Precast plates 71, 72 are installed on the opposite side of the extension portions 18, 19, sandwiching the end of the first tension member 12 between them.

[0058] <Grout filling process S170> In the grout filling process S170, grout is filled into the inside of the sheath tube 17 arranged around the first tendon 12. The sheath tube 17 is provided with an injection hose connected to an injection port formed on the outer surface of the first deck slab 10. When filling with grout, a nipple is provided at the injection port on the underside of the first deck slab 10, and the grout is filled into the inside of the sheath tube 17 from the injection hose. After filling with grout, the nipple is removed, and the injection port is filled with a filler such as resin mortar, thereby closing the injection port.

[0059] In the present invention, the grout filling step S170 may be performed after the precast plate installing step S160, or the precast plate installing step S160 may be performed after the grout filling step S170.

[0060] This completes the precast PC deck joining method S100.

[0061] According to this embodiment, the method includes a connecting step S110 in which one end 13 of the first tendon 12 penetrating the first floor slab 10, which is a precast floor slab, is connected to the second tendon 22 penetrating the second floor slab 20, and the other end 14 of the first tendon 12 of the first floor slab 10 is connected to the third tendon 32 penetrating the third floor slab 30 arranged on the opposite side of the second floor slab 20 across the first floor slab 10, and a tensioning step S150 in which the first tendon 12 is tensioned. As a result, the first floor slab 10 is prestressed by the first tendon 12. That is, the first floor slab 10 can release only the prestress of the first floor slab 10 by releasing the connection between the one end 13 of the first tendon 12 and the second tendon 22 of the second floor slab 20 and releasing the connection between the other end 14 of the first tendon 12 and the third tendon 32 of the third floor slab 30. Therefore, it is possible to replace only the first floor slab 10 that needs to be replaced with a new first floor slab 10.

[0062] According to this embodiment, in the connection step S110, one end 13 of the first tendon 12 is connected to the second tendon 22 of the second deck 20, and the other end 14 of the first tendon 12 is connected to the third tendon 32 of the third deck 30. This allows the first deck 10, which is to be newly installed between the second deck 20 and the third deck 30, to be prestressed and joined. Therefore, instead of joining sequentially in one direction as in the conventional prestressed decks, the tendon 12 can also be tensioned for the deck sandwiched between two existing decks. In this way, construction can be performed from two directions, improving the freedom of construction.

[0063] In addition, according to this embodiment, in the connection step S110, one end 13 of the first tendon 12 is connected to the second tendon 22 of the second deck 20, and the other end 14 of the first tendon 12 is connected to the third tendon 32 of the third deck 30. This allows prestress to be applied to the first deck 10 by the first tendon 12 with both ends connected, and reduces the number of times the first tendon 12 is tensioned. This makes it possible to complete the construction in a short time.

[0064] According to this embodiment, in the tensioning step S150, the linearly extended first tendon 12 is tensioned from a direction inclined with respect to the extension direction X of the first tendon 12. This makes it possible to tension the first tendon 12 even if the space required to apply tension to the first tendon 12 is narrow. This makes it possible to improve the freedom of construction without being subject to spatial restrictions.

[0065] According to this embodiment, in the tensioning step S150, the first tendon 12 is tensioned by a tensioning device 76 provided between the other end 14 of the first tendon 12 and the end of the third tendon 32. This allows the first tendon 12 to be tensioned while being held in a straight line. Therefore, prestress can be applied to the first deck 10 more efficiently than in the case where the first tendon 12 is curved. Also, the thickness of the first deck 10 can be reduced more than in the case where the first tendon 12 is curved.

[0066] In this embodiment, the first tendon 12 is tensioned by a tensioning device 76 provided between the other end 14 of the first tendon and the end of the third tendon 32, but in the present invention, the joining mode at one end 13 and the joining mode at the other end 14 may be reversed, and the first tendon 12 may be tensioned by a tensioning device 76 provided between one end 13 of the first tendon 12 and the end of the second tendon 22. Even in this case, the above-mentioned action and effect can be exerted.

[0067] According to this embodiment, the first deck 10 has a main body 11 through which the first tendon 12 penetrates and which is separated from the second deck 20 and the third deck 30, and extensions 18, 19 which are remaining portions obtained by cutting out both sides of the main body 11 in the extension direction X of the first tendon 12. The first deck 10 further includes a precast plate installation step S160 for installing precast plates 71, 72 on the opposite side of the extensions 18, 19 across both ends 13, 14 of the first tendon 12. As a result, the one end 13 of the first tendon 12 is protected by the extensions 18 and the precast plate 71. In addition, the other end 14 of the first tendon 12 is protected by the extensions 19 and the precast plate 72. This makes it possible to suppress deterioration of the one end 13 and the other end 14 of the first tendon 12 due to corrosion or the like, and improve the durability of the first tendon 12.

[0068] In addition, according to this embodiment, since the extension parts 18, 19 are formed at the upper end of the main body part 11, when the first floor slab 10 is installed between the second floor slab 20 and the third floor slab 30, the first floor slab 10 can be hung down by a crane or the like. Therefore, the first floor slab 10 suspended by a crane or the like can be installed without sliding in the horizontal direction, making it possible to carry out construction with higher safety.

[0069] According to this embodiment, a grout filling step S170 is further provided for filling the sheath tube 17 arranged around the first tendon 12 with grout. This makes it possible to stabilize the first tendon 12 inside the sheath tube 17. This makes it possible to maintain the prestress applied by the first tendon 12 for a longer period of time.

[0070] <Second embodiment: Precast PC floor slab joining method S200> Next, a description will be given of a precast PC deck joining method S200 according to the second embodiment. In this embodiment, a second connector 265 is used.

[0071] 13, the second connector 265 has a first sleeve 266, a second sleeve 267, and a plug 268. The first sleeve 266 is connected to the second fastener 160. The second sleeve 267 is connected to the fourth fastener 35 and is spaced apart from the first sleeve 266. The plug 268 connects the first sleeve 266 and the second sleeve 267. By rotating the plug 268, the distance between the first sleeve 266 and the second sleeve 267 can be adjusted.

[0072] <Second embodiment: Joining method for precast PC floor slabs> Next, the steps of the precast PC deck joining method S200 according to the second embodiment will be described.

[0073] As shown in Figure 14, the method S200 for joining precast PC deck slabs includes a connection process S210 for connecting one end 13 of a first tension member 12 passing through a first deck 10, which is a precast deck, to a second tension member 22 passing through a second deck 20, and for connecting the other end 14 of the first tension member 12 of the first deck 10 to a third tension member 32 passing through a third deck 30 arranged on the opposite side of the second deck 20 across the first deck 10, and a tensioning process S250 for tensioning the first tension member 12.

[0074] <Connection step S210> The connection process S210 includes a first floor slab installation process S120, a second floor slab connection process S130, and a third floor slab connection process S240. The first floor slab installation process S120 and the second floor slab connection process S130 are the same as those in the first embodiment, and therefore will not be described.

[0075] <Third floor slab connection process S240> As shown in Figure 15 (a), after completion of the first deck installation process S120 and the second deck connection process S130, one end 13 of the first tendon 12 is connected to the second tendon 22 of the second deck 20.

[0076] 15(b), in the third floor slab connecting process S240, the second fixing device 160 and the fourth fixing device 35 are connected by the second connector 265. In the third floor slab connecting process S240, a first sleeve 266 is connected to the second fixing device 160, and a second sleeve 267 is connected to the fourth fixing device 35.

[0077] 16(a), in the third deck slab connecting step S240, the first sleeve 266 and the second sleeve 267 are connected by the plug 268. In this manner, in the third deck slab connecting step S240, the other end 14 of the first tendon 12 and the third tendon 32 of the third deck slab 30 are connected by the second connector 265.

[0078] <Tension process S250> 16(b), a tensioning process S250 is performed in which the first tendon 12 is tensioned by the second connector 165 provided between the other end 14 of the first tendon 12 and the end of the third tendon 32. In the tensioning process S250, the plug 268 is rotated to shorten the separation distance between the first sleeve 266 and the second sleeve 267, thereby tensioning the first tendon 12.

[0079] The precast PC deck joining method S200 may further include a precast plate installation step S160 and a grout material filling step S170 after the tensioning step S250.

[0080] According to this embodiment, in the connection step S210, one end 13 of the first tendon 12 is connected to the second tendon 22 of the second deck 20, and the other end 14 of the first tendon 12 is connected to the third tendon 32 of the third deck 30. This allows the first deck 10 to be newly installed between the second deck 20 and the third deck 30 to be prestressed and joined. Therefore, instead of joining sequentially in one direction as in the conventional prestressed decks, the tendon 12 can also be tensioned for the deck sandwiched between two existing decks. In this way, construction can be performed from two directions, improving the freedom of construction.

[0081] According to this embodiment, in the connection step S210, one end 13 of the first tendon 12 is connected to the second tendon 22 of the second deck 20, and the other end 14 of the first tendon 12 is connected to the third tendon 32 of the third deck 30. This allows prestress to be applied to the first deck 10 by the first tendon 12 with both ends connected, and reduces the number of times the first tendon 12 is tensioned. This makes it possible to complete the construction in a short time.

[0082] According to this embodiment, in the tensioning step S250, the first tendon 12 is tensioned by the second connector 165 provided between the other end 14 of the first tendon 12 and the end of the third tendon 32. At this time, tensioning can be achieved by rotating the plug 268 without applying a reaction force to the tensioning force to the precast PC deck itself, making it possible to maintain the tensioning force.

[0083] Furthermore, according to this embodiment, in the tensioning step S250, the first tendon 12 is tensioned by the second connector 165 provided between the other end 14 of the first tendon 12 and the end of the third tendon 32. This allows the first tendon 12 to be tensioned while being held in a straight line. Therefore, prestress can be applied to the first deck 10 more efficiently than in the case where the first tendon 12 is curved. Also, the thickness of the first deck 10 can be reduced more than in the case where the first tendon 12 is curved.

[0084] Furthermore, according to this embodiment, in the tensioning step S250, the first tendon 12 is tensioned by the second connector 165 provided between the other end 14 of the first tendon 12 and the end of the third tendon 32. This allows the first tendon 12 to be tensioned and released without using a large-scale tensioning device. This allows the tensioning and release of the first tendon 12 to be completed in a shorter time.

[0085] In this embodiment, the first tendon 12 is tensioned by the second connector 165 provided between the other end 14 of the first tendon and the end of the third tendon 32, but in the present invention, the joining mode at one end 13 and the joining mode at the other end 14 may be reversed, and the first tendon 12 may be tensioned by the second connector 165 provided between the one end 13 of the first tendon 12 and the end of the second tendon 22. Even in this case, the above-mentioned action and effect can be exerted.

[0086] <Third embodiment: Joining method for precast PC floor slabs> Next, a precast PC deck joining method S300 according to the third embodiment will be described.

[0087] As shown in Figure 17, the joining method S300 for precast PC deck slabs includes a connection process S310 for connecting one end 13 of a first tension member 12 that penetrates a first deck 10, which is a precast deck, to a second tension member 22 that penetrates a second deck 20, and connecting the other end 14 of the first tension member 12 of the first deck 10 to a third tension member 32 of a third deck 30 arranged on the opposite side of the second deck 20 across the first deck 10, and a tensioning process S350 for tensioning the first tension member 12.

[0088] <Connection step S310> The connection process S310 includes a first deck installation process S320 of installing the first deck 10 adjacent to the second deck 20, a second deck connection process S330 of connecting one end 13 of the first tension member 12 to the second tension member 22 of the second deck 20 with a first connector 155, a third deck installation process S331 of installing the third deck 30 adjacent to the first deck 10 on the opposite side of the second deck 20 across the first deck 10, and a third deck connection process S340 of connecting the other end 14 of the first tension member 12 to the third deck 30 with a second connector 165.

[0089] <1st floor slab installation process S320> As shown in Fig. 18(a), the first deck installation process S320 starts with the second deck 20 having been installed. The second deck 20 is prestressed by the second tendon 22, and the third fastener 25 is fixed to the end of the second tendon 22. After the second deck 20 is prestressed, the portion of the second tendon 22 that protrudes to the opposite side of the second deck 20 across the third fastener 25 is cut to a predetermined length.

[0090] As shown in FIG. 18( b ), in the first deck slab installation process S320, a first connector 155 is installed to a third fixing device 25 provided on a second tendon 22.

[0091] Next, as shown in Figure 19(a), in the first deck installation process S320, the first tension member 12 is penetrated through the main body 11 of the first deck slab 10, a first fixing device 150 is installed at one end 13 of the penetrated first tension member 12, and a second fixing device 160 is installed at the other end 14 of the first tension member 12.

[0092] Next, in the first floor slab installation process S320, the first floor slab 10 is placed adjacent to the second floor slab 20.

[0093] <Second floor slab connection process S330> As shown in Figure 19 (b), in the second deck connection process S330, the first connector 155 is connected to the first fixing device 150 installed at one end 13 of the first tendon 12, thereby connecting one end 13 of the first tendon 12 to the second tendon 22 of the second deck 20.

[0094] <3rd floor slab installation process S331> As shown in Fig. 20(a), a third deck installation step S331 is performed in which a third deck 30 is installed adjacent to the first deck 10 on the opposite side of the second deck 20 with the first deck 10 in between. As shown in Fig. 20(b), in the third deck installation step S331, a third tendon 32 is passed through the installed third deck 30, and a fourth fixing device 35 is provided at the end of the third tendon 32. At this point, no prestress is applied to the third deck 30 by the third tendon 32.

[0095] <Third floor slab connection process S340> 21(a), a third deck slab connecting step S340 is performed in which the other end 14 of the first tendon 12 is connected to the third tendon 32 of the third deck slab 30 by the second connector 165. In the third deck slab connecting step S340, the fourth fixing device 35 is connected to the second connector 165, and the second fixing device 160 is connected to the second connector 165. When connecting these to the second connector 165, first, the second connector 165 is placed around the first tendon 12, and the second connector 165 is slid toward the third deck slab 30, and then the other end 14 of the first tendon 12 is connected to the third tendon 32 of the third deck slab 30 by the second connector 165.

[0096] <Tension process S350> Next, as shown in Figure 21(b), a tensioning process S350 is performed in which the linearly extended first tension member 12 and the third tension member 32 are tensioned in a direction along the extension direction of the first tension member 12 (the direction of arrow P in the figure) using a tensioning device not shown.

[0097] The precast PC deck joining method S300 may further include a precast plate installation step S160 and a grout material filling step S170 after the tensioning step S350.

[0098] This completes the precast PC deck joining method S300.

[0099] According to this embodiment, in the connection step S310, after the first floor slab 10 is installed adjacent to the second floor slab 20, one end 13 of the first tendon 12 is connected to the second tendon 22 of the second floor slab 20, and the third floor slab 30 is installed on the opposite side of the second floor slab 20 across the first floor slab 10, and the other end 14 of the first tendon 12 is connected to the third tendon 32 of the third floor slab 30. This makes it possible to tension the tendon 12 of the first floor slab 10 newly installed between the second floor slab 20 and the third floor slab 30, and to apply prestress to the first floor slab 10 and join them. In particular, this is embodied as a method of sequentially extending the PC floor slab in the second extension direction X2.

[0100] According to this embodiment, in the connecting step S310, the other end 14 of the first tendon 12 is connected to the third tendon 32 provided on the third deck 30, and in the tensioning step S350, the first tendon 12 and the third tendon 32 are tensioned simultaneously. This allows the first deck 10 and the third deck 30 to be tensioned simultaneously. Therefore, the tensioning work of the first tendon 12 and the third tendon 32 can be performed efficiently.

[0101] <First embodiment: PC floor slab replacement method S400> Next, a PC floor slab replacement method S400 according to the first embodiment will be described. The PC floor slab replacement method S400 replaces the existing first floor slab 10, which is an existing PC floor slab, with a new first floor slab 10, which is a new PC floor slab.

[0102] As shown in FIG. 22, the PC deck replacement method S400 includes a removal step S410 and a precast PC deck joining method S100.

[0103] <Removal process S410> In the removal process S410, the existing first floor slab 10, which is an existing PC floor slab installed between the second floor slab 20 and the third floor slab 30, is removed.

[0104] As shown in Fig. 23(a), in the removal step S410, first, the precast panels 71, 72 are removed. Then, in the removal step S410, the first connector 155 that connected the first fixing device 150 installed at the one end 13 and the third fixing device 25 installed at the end of the second tendon 22 is removed, and the connection between the one end 13 of the existing first tendon 12, which is an existing tendon that penetrates the existing first deck 10, and the second tendon 22 of the second deck 20 that was connected to the one end 13 of the existing first tendon 12 is released.

[0105] In addition, in the removal process S410, the second connecting device 165 that connected the second fixing device 160 installed at the other end 14 and the fourth fixing device 35 installed at the end of the third tension member 32 is removed, and the connection between the other end 14 of the existing first tension member 12 and the third tension member 32 of the third deck 30 that was connected to the other end 14 of the existing first tension member 12 is disconnected.

[0106] Thereafter, the existing first deck 10, which is an existing PC deck installed between the second deck 20 and the third deck 30, is removed, and the removal process S410 is completed.

[0107] After the removal process S410, the precast PC deck joining method S100 is performed, and the PC deck replacement method S400 is completed. Note that after the removal process S410, the precast PC deck joining method S200 may be performed.

[0108] According to this embodiment, the process includes a removal process S410 for removing the existing first deck 10, which is an existing PC deck installed between the second deck 20 and the third deck 30; a connection process S110 for connecting one end 13 of the first tension member 12 that has penetrated the new first deck 10 to the second tension member 22 of the second deck 20, and connecting the other end 14 of the first tension member 12 of the new first deck 10 to the third tension member 32 of the third deck 30 arranged on the opposite side of the second deck 20 across the new first deck 10; and a tensioning process S150 for tensioning the first tension member 12.

[0109] The existing first deck 10 is prestressed by the existing first tendon 12, and only the existing first deck 10 can be removed by disconnecting one end 13 of the first tendon 12 from the second tendon 22 of the second deck 20 and disconnecting the other end 14 of the first tendon 12 from the third tendon 32 of the third deck 30. Therefore, it becomes possible to replace only the existing first deck 10 that needs to be replaced with a new first deck 10.

[0110] Furthermore, according to this embodiment, instead of joining in sequence in one direction as in conventional prestressed decks, the tendon 12 can also be tensioned for a deck sandwiched between two existing decks. In this way, construction can be performed from two directions, improving the degree of freedom of construction.

[0111] In addition, according to this embodiment, when removing the existing PC deck 80, it is not necessary to chip the existing PC deck 80 to be removed and the second deck 20 and the third deck 30 to be left behind. Therefore, it is possible to remove the existing PC deck 80 in a shorter time.

[0112] Furthermore, according to this embodiment, when removing the existing PC floor slab 80 and replacing it with the new first floor slab 10, there is no need to pour in-situ concrete into the first floor slab 10, the second floor slab 20, and the third floor slab 30. Therefore, the first floor slab 10, the second floor slab 20, and the third floor slab 30 can all be precast floor slabs, making it possible to complete the replacement work in a short period of time.

[0113] <Fourth embodiment: Joining method for precast PC floor slabs> Next, a description will be given of a joining method S500 for precast PC floor slabs according to the fourth embodiment. First, a description will be given of a first floor slab 10 used in the joining method S500 for precast PC floor slabs according to the fourth embodiment.

[0114] As shown in Fig. 24, the first deck 10 used in the joining method S500 of precast PC decks according to the fourth embodiment has a first tendon 12 and a first tendon 42 for applying prestress. The first deck 10 has a main body 11 through which the first tendon 12 and the first tendon 42 pass, and extensions 18 and 19 which are the remaining portions obtained by cutting out both sides of the main body 11.

[0115] The first tendon 12 is inclined with respect to the extension direction X, and one end 13 of the first tendon 12 is disposed higher than the other end 14 of the first tendon 12. The one end 13 of the first tendon 12 and the other end 14 of the first tendon 12 protrude from the main body 11 of the first deck 10.

[0116] A first fixing device 150 is fixed to one end 13 of the first tendon 12. The one end 13 of the first tendon 12 is connected to the second tendon 22 by a first connecting device 155.

[0117] A fifth fixing device 55 is fixed to the other end 14 of the first tendon 12. The fifth fixing device 55 fixes the first tendon 12 to the first deck slab 10. The fifth fixing device 55 has a sleeve 551, a wedge 552, and an fixing member 553.

[0118] The sleeve 551 is provided around the first tendon 12 and is formed in a cylindrical shape. The inner surface of the sleeve 551 is formed as an inclined surface, and a wedge 552 is provided on the inside. The sleeve 551 is provided with an anchoring member 553 on the outer surface. The wedge 552 is placed inside the sleeve 551, and has a wedge-shaped outer shape. The anchoring member 553 uses a ring nut, a shim, or the like, and comes into contact with the first deck slab 10.

[0119] The first tendon 42 is made of, for example, a PC steel strand and is inclined with respect to the extension direction X. One end 43 of the first tendon 42 is disposed lower than the other end 44 of the first tendon 42. A sheath tube 47 is provided around the first tendon 42, and the sheath tube 47 is filled with grout material. Note that the first tendon 42 can also use a continuous fiber reinforcing material such as carbon fiber or resin fiber as the tendon.

[0120] A sixth fixing device 65 is fixed to one end 43 of the first tendon 42. The sixth fixing device 65 fixes the first tendon 42 to the first deck 10. The sixth fixing device 65 has a sleeve 651, a wedge 652, and an fixing member 653.

[0121] The sleeve 651 is provided around the first tendon 42 and is formed in a cylindrical shape. The inner surface of the sleeve 651 is formed as an inclined surface, and a wedge 652 is provided on the inside. The sleeve 651 is provided with an anchoring member 653 on the outer surface. The wedge 652 is placed inside the sleeve 651, and has a wedge-shaped outer shape. The anchoring member 653 uses a ring nut, a shim, or the like, and comes into contact with the first deck slab 10.

[0122] A second fixing device 160 is fixed to the other end 44 of the first tendon 42. The other end 44 of the first tendon 42 is connected to the third tendon 32 by a second connecting device 165.

[0123] <Second embodiment: PC deck replacement method> Next, the PC floor slab replacement method S600 according to the second embodiment will be described together with the precast PC floor slab joining method S500 according to the fourth embodiment. The PC floor slab replacement method S600 replaces the existing PC floor slab 80 with a new PC floor slab, the first floor slab 10. This first floor slab 10 is constructed by the precast PC floor slab joining method S500 according to the fourth embodiment.

[0124] As shown in FIG. 25, the PC deck replacement method S600 includes a removal step S610 and a precast PC deck joining method S500.

[0125] As shown in Figure 26 (a), the existing PC deck 80 is a PC deck and has existing tendons 82 for applying prestress. The existing PC deck 80 is installed between the second deck 20 and the third deck 30. The existing tendons 82 penetrate the second deck 20, the third deck 30, and the existing PC deck 80.

[0126] <Removal process S610> In the removal process S610, the existing PC deck 80 installed between the second deck 20 and the third deck 30 is removed. The removal process S610 includes a chipping process S620, a holding process S630, and a cutting process S640.

[0127] <Scamping process S620> 26(b), in the chipping process S620, the end portion on the second slab 20 side and the end portion on the third slab 30 side of the existing PC deck 80 installed between the second slab 20 and the third slab 30 are chipped to expose the existing tendons 82 that penetrate the second slab 20, the third slab 30, and the existing PC deck 80. When chipping the existing PC deck 80, a chipping means such as a water jet is used.

[0128] <Holding process S630> As shown in Figure 27(a), in the retaining process S630, the first retaining device 51 is used to retain the tension of the existing tension member 82 that penetrates the second deck 20 so that it functions as a second tension member, and the second retaining device 52 is used to retain the tension of the existing tension member 82 that penetrates the third deck 30 so that it functions as a third tension member.

[0129] The first holding device 51 has a support plate 501, a long shim 502, a short shim 503, an intermediate grip 504, and a catamaran jack 505. The second holding device 52 has the same configuration as the first holding device 51, and therefore a description thereof will be omitted.

[0130] In the holding step S630, the bearing plate 501 is installed on the exposed existing tendon 82, and the bearing plate 501 is brought into contact with the second deck 20. Also, in the holding step S630, the long shim 502, the short shim 503, and the intermediate grip 504 are installed on the exposed existing tendon 82. As a result, the first holding device 51 is installed on the existing tendon 82 on the second deck 20 side. Similarly, on the third deck 30 side, the second holding device 52 is installed on the exposed existing tendon 82.

[0131] As shown in FIG. 27(b), in the holding step S630, the catamaran jack 505 is installed on the intermediate grip 504, and a predetermined tension is applied to the intermediate grip 504 by the catamaran jack 505, so that the tension of the existing tendon 82 penetrating the second deck 20 is held by the intermediate grip 504. Similarly, the tension of the existing tendon 82 penetrating the third deck 30 is held. As a result, the existing tendon 82 penetrating the second deck 20 functions as the second tendon. The existing tendon 82 penetrating the third deck 30 functions as the third tendon. Then, a new shim 506 for holding tension is inserted into the gap generated between the long shim 502 and the short shim 503 due to elongation of the tendon due to tension, etc.

[0132] As shown in Figure 28 (a), in the retention process S630, the tension of the existing tendon 82 that penetrates the second deck 20 is maintained, and the tension of the existing tendon 82 that penetrates the third deck 30 is maintained, and then the catamaran jack 505 is removed.

[0133] <Cutting process S640> As shown in FIG. 28(b), in the cutting process S640, the existing tendons 82 between the first retaining device 51 and the second retaining device 52 are cut, and the existing PC deck 80 is removed.

[0134] Next, the precast PC deck joining method S500 is performed.

[0135] The method S500 for joining precast PC deck slabs includes a connection process S510 for connecting one end 13 of a first tension member 12 that penetrates a first deck 10, which is a precast deck, to a second tension member 22 that penetrates a second deck 20, and for connecting the other end 44 of the other first tension member 42 that penetrates the first deck 10 to a third tension member 32 that penetrates a third deck 30 arranged on the opposite side of the first deck 10 to the second deck 20, and a tensioning process S550 for tensioning the first tension member 12 from the other end 14 side of the first tension member 12 and tensioning the first tension member 42 from one end 43 side of the first tension member 42.

[0136] <Connection step S510> The connecting step S510 includes a first floor slab installation step S520, a second floor slab connecting step S530, and a third floor slab connecting step S540.

[0137] <1st floor slab installation process S520> 29(a), in the first deck installation process S520, a third fixing device 25 is installed on the existing tendon 82 that penetrates the second deck 20, which is the second tendon, and a first connector 155 is installed on the third fixing device 25. Also, in the first deck installation process S520, a fourth fixing device 35 is installed on the existing tendon 82 that penetrates the third deck 30, which is the third tendon, and a second connector 165 is installed on the fourth fixing device 35.

[0138] Then, in the first floor slab installation process S520, the first floor slab 10 is placed between the second floor slab 20 and the third floor slab 30.

[0139] 29(b), in the first deck installation process S520, the first tension member 12 is penetrated through the main body 11 of the first deck slab 10, and a first fixing device 150 is installed at one end 13 of the penetrated first tension member 12. Also, in the first deck installation process S520, the first tension member 42 is penetrated through the main body 11 of the first deck slab 10, and a second fixing device 160 is installed at the other end 44 of the penetrated first tension member 42.

[0140] <Second floor slab connection process S530> Next, a second deck connecting step S530 is performed in which one end 13 of the first tendon 12 and the second tendon 22 of the second deck 20 are connected by a first connector 155. In the second deck connecting step S530, the first connector 155 is connected to a first fixing device 150 installed at one end 13 of the first tendon 12, thereby connecting one end 13 of the first tendon 12 and the second tendon 22 of the second deck 20. In the second deck connecting step S530, a fifth fixing device 55 is installed at the other end 14 of the first tendon 12.

[0141] <Third floor slab connection process S540> Next, a third deck slab connecting step S540 is performed in which the other end 44 of the first tendon 42 and the third tendon 32 of the third deck slab 30 are connected by a second connector 165. In the third deck slab connecting step S540, the other end 44 of the first tendon 42 and the third tendon 32 of the third deck slab 30 are connected by connecting the second connector 165 to a second fixing device 160 installed at the other end 44 of the first tendon 42. In the third deck slab connecting step S540, a sixth fixing device 65 is installed at one end 43 of the first tendon 42.

[0142] <Tension process S550> Next, as shown in Figure 30(a), in the tensioning process S550, a tensioning device 77 is installed in the fifth fixing device 55, and the first tension member 12 is tensioned from the other end 14 side of the first tension member 12 by the tensioning device 77. Also, in the tensioning process S550, a tensioning device 77 is installed in the sixth fixing device 65, and the first tension member 42 is tensioned from the one end 43 side of the first tension member 42 by the tensioning device 77.

[0143] As shown in FIG. 30(b), in the tensioning step S550, after tensioning of the first tendon 12 and the first tendon 42 is completed, the first retaining device 51 and the second retaining device 52 are removed.

[0144] The precast PC deck joining method S500 may further include a precast plate installation step S160 and a grout material filling step S170 after the tensioning step S550.

[0145] This completes the PC deck replacement method S600.

[0146] According to this embodiment, the process includes a removal process S610 for removing the existing PC deck 80 installed between the second deck 20 and the third deck 30, a connection process S510 for connecting one end 13 of the first tension member 12 penetrating the new first deck 10 to the second tension member 22 penetrating the second deck 20 after installing a new first deck 10, which is a precast deck, between the second deck 20 and the third deck 30, and connecting the other end 44 of the first tension member 42 of the new first deck 10 to the third tension member 32 penetrating the third deck 30 arranged on the opposite side of the second deck 20 across the new first deck 10, and a tensioning process S550 for tensioning the first tension member 12 from the other end 14 side of the first tension member 12 and tensioning the first tension member 42 from the one end 43 side of the first tension member 42. This allows a new first floor slab 10 to be installed in the location where the existing PC floor slab 80 has been removed. Therefore, it is possible to replace only the existing PC floor slab 80 that needs to be replaced with the new first floor slab 10.

[0147] According to this embodiment, the removal process S610 includes a chipping process S620 in which the end portion of the existing PC deck 80 installed between the second deck 20 and the third deck 30 on the second deck 20 side and the end portion on the third deck 30 side are chipped to expose the existing tension member 82 that has penetrated the second deck 20, the third deck 30, and the existing PC deck 80; a retaining process S630 in which the tension member 82 that has penetrated the second deck 20 is maintained using a first retaining device 51 to form a second tension member, and the tension member 82 that has penetrated the third deck 30 is maintained using a second retaining device 52 to form a third tension member; and a cutting process S640 in which the existing tension member 82 between the first retaining device 51 and the second retaining device 52 is cut. As a result, even in a conventional PC deck in which the existing tendons 82 penetrate the second deck 20, the third deck 30, and the existing PC deck 80, a new first deck 10 can be installed in the location where the existing PC deck 80 has been removed. Therefore, it is possible to replace only the existing PC deck 80 that needs to be replaced with the new first deck 10.

[0148] In addition, according to this embodiment, when removing the existing PC deck 80, only the existing PC deck 80 to be removed is chipped, and there is no need to chip the second deck 20 and the third deck 30 that are left behind. Therefore, it is possible to remove the existing PC deck 80 in a short time.

[0149] Furthermore, according to this embodiment, when removing the existing PC floor slab 80 and replacing it with the new first floor slab 10, there is no need to pour in-situ concrete into the first floor slab 10, the second floor slab 20, and the third floor slab 30. Therefore, the first floor slab 10, the second floor slab 20, and the third floor slab 30 can all be precast floor slabs, making it possible to complete the replacement work in a short period of time.

[0150] Furthermore, according to this embodiment, the tendon 12 can be tensioned even for a deck sandwiched between two existing decks. In this way, construction can be performed from two directions, improving the degree of freedom of construction.

[0151] In the PC deck replacement method S600, the precast PC deck joining method S100, S200 may be performed instead of the precast PC deck joining method S500.

[0152] <Third embodiment: PC deck replacement method> Next, a PC deck replacement method S700 according to the third embodiment will be described.

[0153] As shown in Figure 31, the PC deck replacement method S700 of the third embodiment includes a removal process S710 in which the first deck 10 constructed by the precast PC deck joining method S500 of the fourth embodiment is removed as an existing PC deck.

[0154] 32(a), in the removal process S710, a first retaining device 51 is installed between the third fixing device 25 and the second deck 20 to maintain the tension of the second tendon 22. Also, in the removal process S710, a second retaining device 52 is installed between the fourth fixing device 35 and the third deck 30 to maintain the tension of the third tendon 32.

[0155] In the removal process S710, the connection between the first fixing device 150 and the first connecting device 155 provided at one end 13 of the existing first tension member 12 that penetrates the existing first deck slab 10, which is an existing PC deck, is disconnected, thereby disconnecting the connection between one end 13 of the existing first tension member 12 and the second tension member 22 of the second deck slab 20.

[0156] Then, in the removal process S710, the connection between the second fixing device 160 and the second connecting device 165 provided on the other end 44 of the existing first tension member 42 that penetrates the existing first deck slab 10 is disconnected, thereby disconnecting the other end 44 of the existing first tension member 42 from the third tension member 32 of the third deck slab 30.

[0157] Thereafter, as shown in FIG. 32(b), in the removal process S710, the first deck slab 10, which is the existing PC deck slab, is removed.

[0158] According to this embodiment, when removing the existing PC deck 80, it is not necessary to chip the existing PC deck 80 to be removed and the second deck 20 and the third deck 30 to be left behind. Therefore, it is possible to remove the existing PC deck 80 in a shorter time.

[0159] Furthermore, according to this embodiment, when removing the existing PC floor slab 80 and replacing it with the new first floor slab 10, there is no need to pour in-situ concrete into the first floor slab 10, the second floor slab 20, and the third floor slab 30. Therefore, the first floor slab 10, the second floor slab 20, and the third floor slab 30 can all be precast floor slabs, making it possible to complete the replacement work in a short period of time.

[0160] After the removal process S710, in the PC floor slab replacement method S700 according to the third embodiment, the precast PC floor slab joining method S500 is performed. In the PC floor slab replacement method S700 according to the third embodiment, the precast PC floor slab joining method S100 or S200 may be performed instead of the precast PC floor slab joining method S500.

[0161] Although some of the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. In addition, these embodiments can be implemented in appropriate combinations. Furthermore, the present invention can be implemented in various new forms in addition to the above-mentioned several embodiments. Therefore, each of the above-mentioned several embodiments can be variously omitted, replaced, and modified without departing from the gist of the present invention. Such new forms and modifications are included in the scope and gist of the present invention, and are included in the scope of the invention described in the claims and the equivalents of the invention described in the claims. [Explanation of symbols]

[0162] 10:1st floor slab 11: Main body 12:1st tendon 13:One end 14:Other end 17: Sheath tube 18: Extension part 19: Extension part 42: 1st tension material 43:One end 44:Other end 47: Sheath tube 150: First fixing device 151: Sleeve 152: Wedge 153: Retaining washer 154: Bolt 155: First connector 160: Second fixing device 161: Sleeve 162: Wedge 163: Fixing member 165: Second connector 166: Screw bushing 167: Connection sleeve 168: Connection bolt 265: Second connector 266: 1st sleeve 267: 2nd sleeve 268: Plug 55: 5th fixing device 551: Sleeve 552: Wedge 553: Fixing member 65: 6th fixing device 651: Sleeve 652: Wedge 653: Fixing member 71: Precast plate 73: Horizontal fastening member 72: Precast plate 74: Horizontal fastening member 20: 2nd floor slab 22:Second tension material 25: Third fixing device 251: Sleeve 252: Wedge 30: 3rd floor slab 32:Third tension material 35: 4th fixing device 351: Sleeve 352: Wedge 353: Fixing member 51: 1st holding device 52:Second holding device 75: Tension device 76: Tension device 761: Tension jack 762: Pulling Head 77: Tension device 78: Tensioning connector 781: Screw bushing 782: Tension sleeve 783: U-shaped chair 784: Curved chair 785: Straight chair 786: Fixing bolt 787: Grip 788: PC steel strand for tensioning 789: Pulling wire 80: Existing PC deck 82: Existing tendon 90:PC floor slab 91 :Structure 92: Tensile material 95: Fixture 97: Tensile material 98: Fixture S100:Joining method S110: Connection process S120: 1st floor slab installation process S130: Second floor slab connection process S140: Third floor slab connection process S142: Second fastener connection process S150: Tension process S160: Precast plate installation process S170: Grout filling process S200:Joining method S210: Connection process S240: Third floor slab connection process S250: Tension process S300:Joining method S310: Connection process S320: 1st floor slab installation process S330: Second floor slab connection process S331: Third floor slab installation process S340: Third floor slab connection process S350: Tension process S400: Replacement method S410: Removal process S500: Joining method S510: Connection process S520: 1st floor slab installation process S530: Second floor slab connection process S540: Third floor slab connection process S550: Tension process S600: Replacement method S610: Removal process S620: Scouring process S630: Holding process S640: Cutting process S700: Replacement method S710: Removal process X: Stretching direction X1: 1st stretching direction X2: Second extension direction Y: width direction Z : Up and down direction

Claims

1. A method for replacing an existing PC deck with a new PC deck, comprising: A removal process of removing the existing PC deck installed between the second deck and the third deck; a connection process in which a first deck, which is a precast deck, is installed at the location from which the existing PC deck has been removed, one end of a first tendon passing through the first deck is connected to a second tendon passing through the second deck, and the other end of the first tendon is connected to a third tendon passing through the third deck; and a tensioning step of tensioning the first tendon. A method for replacing a PC deck, comprising:

2. In the removing step, The connection between one end of the existing tension member that penetrates the existing PC deck and the second tension member that penetrates the second deck and that was connected to one end of the existing tension member is released; The other end of the existing tendon is disconnected from the third tendon of the third deck that was connected to the other end of the existing tendon; Remove the existing PC floor slab.

2. A method for replacing a PC deck according to claim 1.

3. In the removing step, The second tendon of the second deck is disconnected from one end of an existing tendon that has been connected to the second tendon and penetrated into the existing PC deck; The third tendon of the third deck is disconnected from the other end of another existing tendon different from the one existing tendon that penetrates the existing PC deck and was connected to the third tendon; Remove the existing PC floor slab.

2. A method for replacing a PC deck according to claim 1.

4. The removing step includes: A chipping process in which an end portion of the existing PC deck installed between the second deck and the third deck is chipped off at the second deck side end and the third deck side end of the existing PC deck to expose an existing tendon that penetrates the second deck, the third deck, and the existing PC deck; Using a first retaining device, a tension force of the existing tendon penetrating the second deck is maintained; A retaining step of retaining the tension of the existing tendon that penetrates the third deck using a second retaining device; and a cutting step of cutting the existing tendon between the first holding device and the second holding device.

2. A method for replacing a PC deck according to claim 1.

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