Guard fence and method for installing guard fence

Abstract

To shorten a traffic regulation period necessary for fixing a guard fence.SOLUTION: A guard fence 1A for partitioning a road 50 formed by floor slabs 21, 22, 23, 24 includes: the floor slabs 22, 23; a guard fence part 10A for partitioning the road 50; a floor slab through-hole part 20h vertically penetrating the floor slabs 22, 23; and a fixing member 30 inserted into the floor slab through-hole part 20h and fixing the guard fence part 10A to the floor slabs 22, 23. Since the guard fence part 10A is fixed to the floor slabs 22, 23 by the fixing member 30 that is inserted into the floor slab through-hole part 20h vertically penetrating the floor slabs 22, 23 and fixes the guard fence part 10A to the floor slabs 22, 23, more of work required to fix the guard fence part to the floor slabs can be done from lower surfaces of the floor slabs than in the conventional technique in which a temporary guard fence is fixed to the floor slabs by anchors driven into upper surfaces of the floor slabs. Therefore, a traffic restriction period required to install the guard fence can be shortened.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a safety fence and a method for installing the safety fence. [Background technology]

[0002] A technology has been proposed for replacing the existing deck slab that forms the road of a bridge with a new deck slab. During the construction period for replacing the deck slab of one lane of the road, it is desirable to keep the other lanes of the road in service for vehicle traffic. For this reason, for example, Patent Document 1 discloses a technology for installing temporary guardrails on the road to separate the lane where construction for replacing the existing deck slab is underway from the lane that is in service for vehicle traffic. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-9396 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned technology discloses the installation of a temporary protective fence to prevent vehicles from leaving their lanes, in order to safely carry out deck replacement work in another lane (lane A) while keeping one lane (lane B) open. To install a temporary protective fence strong enough to withstand the impact of a vehicle leaving its lane, it is necessary to restrict traffic and close the lane. Therefore, the traffic restriction period required to install the protective fence is long.

[0005] Therefore, an object of the present invention is to provide a protective fence and a method for installing a protective fence that can shorten the traffic restriction period required to install the protective fence. [Means for solving the problem]

[0006] The present invention is a protective fence that divides a road formed by a deck slab, and the protective fence comprises a first protective fence section that extends along the lane of the road divided by the protective fence, and a second protective fence section that extends along the lane and is continuous with the first protective fence section, and the connecting section that connects the first protective fence section and the second protective fence section has a convex section on one side and a concave section on the other side when viewed vertically, and the convex section and the concave section are interlockable.

[0007] According to this configuration, the protective fence that divides a road formed by a deck slab comprises a first protective fence section that extends along the lane of the road divided by the protective fence, and a second protective fence section that extends along the lane, continuous with the first protective fence section.The connecting section that connects the first protective fence section and the second protective fence section has a convex section on one side and a concave section on the other side when viewed vertically, and since the convex section and the concave section can be fitted together, it is easy to connect the first protective fence section and the second protective fence section, and the traffic restriction period required to install the protective fence can be shortened.

[0008] In this case, it is preferable that the protrusions and recesses have locking portions that limit movement in the direction along the lane.

[0009] With this configuration, the convex and concave portions have locking portions that limit movement in the direction along the lane, making it easy to connect the first protective fence portion and the second protective fence portion, and shortening the traffic restriction period required to install the protective fence.

[0010] It is also preferable to further provide a deck slab through-hole portion that penetrates the deck slab from top to bottom, and a fixing member consisting of a rod protruding below the first protective fence portion and the second protective fence portion, which is inserted into the deck slab through-hole portion and fixes the first protective fence portion and the second protective fence portion to the deck slab.

[0011] With this configuration, the first and second protective fence sections are fixed to the deck slab by fixing members that are inserted into the deck slab through-holes that penetrate the deck slab from top to bottom, so compared to conventional technology in which temporary protective fences are fixed to the deck slab with anchors driven into the top surface of the deck slab, more of the work required to fix the protective fence sections to the deck slab can be done from the underside of the deck slab, thereby shortening the period of traffic restrictions required to install the protective fences.

[0012] The present invention also provides a method for installing guardrails that divide a road formed by deck slabs, the method comprising a first guardrail section installation step of installing a first guardrail section so that it extends along the traffic lane of the road divided by the guardrail, and a second guardrail section installation step of installing a second guardrail section so that it extends along the traffic lane and is continuous with the first guardrail section, wherein in the first guardrail section installation step and the second guardrail section installation step, the connecting section that connects the first guardrail section and the second guardrail section has a convex section on one side and a concave section on the other side when viewed vertically, and the convex section and the concave section are interlocking with each other.

[0013] In this case, in the first protective fence section installation process and the second protective fence section installation process, it is preferable to install the first protective fence section and the second protective fence section in the convex section and the concave section, which have locking sections that limit movement in the direction along the lane.

[0014] Furthermore, in the first protective fence section installation process, it is preferable that a first protective fence section consisting of a rod protruding below the first protective fence section and having a fixing member for fixing the first protective fence section to the deck slab is installed on a deck slab having a deck slab through-hole section that penetrates the deck slab from top to bottom, by inserting the rod into the deck slab through-hole section, and that in the second protective fence section installation process, a second protective fence section consisting of a rod protruding below the second protective fence section and having a fixing member for fixing the second protective fence section to the deck slab is installed on a deck slab having a deck slab through-hole section, by inserting the rod into the deck slab through-hole section. [Effects of the Invention]

[0015] According to the protective fence and the method for installing the protective fence of the present invention, the traffic restriction period required to fix the protective fence can be shortened. [Brief explanation of the drawings]

[0016] [Figure 1] (A), (B), (C), (D), (E) and (F) are longitudinal cross-sectional views perpendicular to the road travel direction showing each step of the deck replacement construction method according to the first embodiment. [Figure 2] (A) is a plan view showing the first embodiment of the protective fence in which the protective fence section is fixed to an existing deck slab, (B) is a cross-sectional view of (A) taken along the alpha line, and (C) is a cross-sectional view of (A) taken along the beta line. [Figure 3] (A), (B), (C), (D), (E), (F), and (G) are longitudinal cross-sectional views perpendicular to the road travel direction, showing each step after FIG. 1(F) of the deck replacement construction method according to the first embodiment. [Figure 4] (A) is a plan view showing the first embodiment of the protective fence in which the protective fence section is fixed to a newly constructed precast deck, (B) is a cross-sectional view of (A) taken by gamma rays, and (C) is a cross-sectional view of (A) taken by delta rays. [Figure 5] (A) is a plan view showing a protective fence according to the first embodiment, in which the protective fence section is fixed to a newly constructed precast deck slab in a manner different from that shown in Figures 4(A), 4(B), and 4(C), and (B) is a cross-sectional view along the ε line of (A). [Figure 6] (A) is a plan view showing a protective fence according to the first embodiment in which the protective fence section is fixed to a newly constructed precast deck slab in a manner different from that shown in Figures 4(A), 4(B), 4(C), 5(A) and 5(B), and (B) is a cross-sectional view taken along the ζ line in (A). [Figure 7] (A) is a plan view showing a protective fence according to the second embodiment in which the protective fence section is fixed to a newly constructed precast deck, (B) is a cross-sectional view taken along the η line of (A), and (C) is a cross-sectional view taken along the θ line of (A). [Figure 8](A) is a plan view showing a protective fence according to the third embodiment in which the protective fence section is fixed to a newly constructed precast deck, (B) is a cross-sectional view taken along line ι of (A), (C) is a cross-sectional view taken along line κ of (A), and (D) is a diagram showing the state in which temporary reinforcement material has been installed before the protective fence section is fixed by the fixing member as in (B). [Figure 9] (A) is a plan view showing a protective fence according to the fourth embodiment in which the protective fence section is fixed to a newly constructed precast deck, (B) is a cross-sectional view of (A) taken along the λ line, and (C) is a cross-sectional view of (A) taken along the μ line. [Figure 10] (A) is a plan view showing a protective fence according to the fifth embodiment in which the first protective fence section and the second protective fence section are fixed to a newly constructed precast deck, (B) is a cross-sectional view taken along the ν line of (A), and (C) is a cross-sectional view taken along the ξ line of (A). [Figure 11] (A) is a plan view showing details of the connection portion in the top beam of Figure 10(A), (B) is a cross-sectional view along line O of details of the connection portion in the middle beam of Figure 10(C), and (C) is a diagram showing the state in which the second protective fence section is connected to the first protective fence section in the second protective fence section installation process of the protective fence of Figure 10(C). [Figure 12] (A) is a plan view showing a protective fence according to the sixth embodiment in which a first protective fence section and a second protective fence section are fixed to a newly constructed precast deck, and (B) is a cross-sectional view taken along the π line of (A). [Figure 13] (A) is a plan view showing details of the connection portion in the top beam of Figure 12(A), (B) is a plan view showing details of the connection portion in the middle beam of Figure 12(B), and (C) is a diagram showing the state in which the second protective fence section is connected to the first protective fence section in the second protective fence section installation process of the protective fence of Figure 11(C). DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, a guardrail, a guardrail installation method, and a deck replacement method according to embodiments of the present invention will be described in detail with reference to the drawings. The deck replacement method according to a first embodiment of the present invention is applied to replacing the deck 20 of a road 50 having multiple lanes 51, 52 as shown in Figure 1(A). The guardrail and guardrail installation method according to this embodiment are applied, for example, to the deck replacement method according to this embodiment.

[0018] As shown in FIG. 1(A), the existing deck 20 that forms the road 50 is erected on bridge girders 41. A pavement 28 is formed on most of the upper surface of the deck 20, which corresponds to the road surface of the road 50, excluding both ends in the width direction of the road 50. A wall parapet 42 is installed on both ends of the deck 20, which correspond to both ends in the width direction of the road 50. In the example of FIG. 1(A), the top of the existing deck 20 is used as a road 50 with two lanes 51, 52 on each side, for the passage of vehicles V.

[0019] In the deck replacement construction method of this embodiment, even during work to replace the deck 20 in one of the two lanes 51, 52 of the road 50, the other of the lanes 51, 52 continues to be used for the passage of vehicles V. Therefore, in order to separate one of the lanes 51, 52 on which work to replace the deck 20 is being carried out from the other of the lanes 51, 52 that is used for the passage of vehicles V, a protective fence 1A that separates the road formed by the deck slab 20 is installed on the road 50, as shown in Figures 2(A), 2(B), 2(C), 4(A), 4(B), and 4(C).

[0020] As shown in FIG. 1(B), the existing deck slab 20 is divided into two existing deck slabs 21 and 22 along the traveling direction of the road 50 and lanes 51 and 52. The deck slab 21 is replaced first, and the deck slab 22 is used for vehicle V passage during the replacement work of the deck slab 21. As shown in FIG. 1(B), in the deck replacement method of this embodiment, an existing deck slab through hole forming process is performed to form an existing deck slab through hole 22h (decorative slab through hole 20h) that vertically penetrates the existing deck slab 22 in a portion 52 of the multiple lanes 51 and 52. The existing deck slab through hole forming process corresponds to the deck slab through hole forming process in the protective fence installation method of this embodiment. The existing deck slab through hole 22h also vertically penetrates the pavement 28 on the top surface of the existing deck slab 22.

[0021] In the existing deck slab through hole portion forming process, the existing deck slab through hole portion 22h is formed by drilling a hole from the upper surface of the existing deck slab 22, but it can also be formed by drilling a hole from the underside of the existing deck slab 22 using a drill bit or the like. In this case, in the existing deck slab through hole portion forming process, no work on the road surface of the road 50 is required. Therefore, during the existing deck slab through hole portion forming process and the deck slab through hole portion forming process for the existing deck slab 22, the lanes 51, 52 can be used for the passage of vehicles V.

[0022] When the existing deck slab through-hole portion 22h is formed by drilling from the underside of the existing deck slab 22, the passage of vehicles V may be restricted, for example, by placing a road cone or the like on the upper surface of the pavement 28 at the location where the existing deck slab through-hole portion 22h is to be formed. Also, when the existing deck slab through-hole portion 22h is formed by drilling from the underside of the existing deck slab 22 with a drill bit, an iron plate or the like may be laid on the upper surface of the pavement 28 at the location where the existing deck slab through-hole portion 22h is to be formed, as necessary, to prevent the tip of the drill bit from protruding from the upper surface of the pavement 28.

[0023] As shown in FIG. 1(C), the wall parapet 42 is removed from the existing deck slab 21 to be replaced first. As shown in FIGS. 1(C), 1(D), 2(A), 2(B), and 2(C), in the deck replacement method of this embodiment, a guardrail section 10A that defines a portion of the traffic lane 52 is placed on the pavement 28 of the existing deck slab 22 in which the existing deck slab through-hole section 22h has been formed in the existing deck slab through-hole section forming step, and an existing deck slab guardrail section fixing step is performed in which the guardrail section 10A is fixed on the pavement 28 of the existing deck slab 22 by fixing members 30 inserted into the existing deck slab through-hole section 22h. The existing deck slab guardrail section fixing step corresponds to the guardrail section fixing step in the guardrail installation method of this embodiment.

[0024] 2(B) and 2(C), the fixing member 30 is made up of a rod 31 protruding below the protective fence section 10A and a fastening member 32 that fits into the rod 31. For example, the rod 31 is a bolt, that is, a rod with an external thread formed therein, or a member consisting of a rod with an external thread formed therein and a head, and the fastening member 32 is, for example, a nut. As shown in FIG. 1(C), in the existing deck slab protective fence section fixing step, the protective fence section 10A is lowered vertically using a lifting machine such as an erection machine, and the rod 31 is inserted into the existing deck slab through-hole 22h formed in the deck slab through-hole forming step, and the protective fence section 10A is placed on the pavement 28 of the deck slab 22. Also, as shown in Figures 1(D), 2(A), 2(B) and 2(C), in the existing deck slab protective fence section fixing process, after the protective fence section 10A is placed on the deck slab 22, the protective fence section 10A is fixed onto the pavement 28 of the deck slab 22 by working from the underside of the deck slab 22 and fitting the fastening member 32 into the rod 31 inserted into the existing deck slab through-hole section 22h.

[0025] In the existing deck slab protective fence section fixing process, a lower plate having a contact surface that contacts the underside of the deck slab 22 and an insertion hole through which the rod 31 is inserted may be applied to ensure the bearing area. In the existing deck slab protective fence section fixing process, the lower plate may be attached to the rod 31 so that the rod 31 inserted through the existing deck slab through-hole 22h is further inserted into the insertion hole of the lower plate, and then fastening members 32 may be fitted onto the rod 31, and the protective fence section 10A may be fixed by the fastening members 32 via the lower plate. This increases the bearing area.

[0026] The following describes a protective fence 1A of this embodiment in which a protective fence section 10A is fixed to an existing deck slab 22. As shown in Figures 2(A), 2(B), and 2(C), the protective fence 1A of this embodiment defines a road 50 formed by deck slabs 21, 22. The protective fence 1A includes the existing deck slab 22, a protective fence section 10A that defines the road 50, an existing deck slab through-hole section 22h (deck slab through-hole section 20h) that passes vertically through the deck slab 22, and fixing members 30 (rods 31 and fastening members 32) that are inserted into the existing deck slab through-hole section 22h and fix the protective fence section 10A to the deck slab 22.

[0027] The protective fence section 10A is made of steel. The protective fence section 10A has a support post 11A, a beam 12A, a support post base plate 13A, a reinforcing rib 14A, and a protective plate 15. The support post 11A extends from the pavement 28 on the upper surface of the deck slab 22 in a direction perpendicular to the upper surface of the deck slab 22. The support post 11A supports the beam 12A, which extends in the direction of travel of the road 50, from below the beam 12A. The support post base plate 13A is a steel plate that extends in a direction parallel to the upper surface of the deck slab 22. The support post base plate 13A is integrated with the support post 11A at the lower end of the support post 11A, and fixes the support post 11A to the deck slab 22.

[0028] The support base plate 13A includes a plate hole 13h that passes through the support base plate 13A from top to bottom. The plate hole 13h has a threaded inner surface that corresponds to the threaded groove of the bolt, which is the rod 31 of the fixing member 30. In the process of fixing the existing deck slab protective fence section described above, the rod 31, which is the bolt, is threaded into the plate hole 13h in advance to be integrated with the protective fence section 10A, and is transported and placed by an erection machine or the like in a state where it protrudes below the support base plate 13A of the protective fence section 10A.

[0029] Therefore, immediately after the rods 31 are inserted into the existing deck slab through-holes 22h and the guardrail fence section 10A is placed on the deck slab 22, and before the fastening members 32 are fitted to the rods 31, the guardrail fence section 10A is positioned on the deck slab 22 so as not to shift laterally. In this state, the guardrail fence section 10A functions as, for example, a Class A guardrail fence in accordance with the guardrail fence installation standards of the Ministry of Land, Infrastructure, Transport and Tourism. Therefore, immediately after the guardrail fence section 10A is placed on the deck slab 22 and before the fastening members 32 are fitted to the rods 31, the lane 52 formed by the deck slab 22 can be used for the passage of vehicles V.

[0030] Furthermore, the inner diameter of the existing deck slab through-hole portion 22h is sufficiently larger than the diameter of the rod 31. When the fastening member 32 is fitted into the rod 31, it is preferable that the outer peripheral surface of the rod 31 inserted into the existing deck slab through-hole portion 22h and the inner peripheral surface of the existing deck slab through-hole portion 22h are not in contact with each other. By keeping them out of contact, when the fastening member 32 is fitted into the rod 31, the protective fence portion 10A is fixed and secured to the deck slab 22 by the frictional force between the support base plate 13A and the deck slab 22. When the fastening member 32 is fitted into the rod 31, the protective fence portion 10A functions, for example, as a Type SB protective fence in accordance with the Ministry of Land, Infrastructure, Transport and Tourism's standards for installing protective fences.

[0031] A pair of reinforcing ribs 14A are provided between the lower part of the side surface of the support pillar 11A on the lane 51 side and the side surface on the lane 52 side and the support pillar base plate 13A. A pair of protective plates 15 extending in a direction perpendicular to the upper surface of the deck slab 22 and along the traveling direction of the road 50 are attached to the side surface of the support pillar 11A on the lane 51 side and the lane 52 side below the beam 12A.

[0032] The lanes 52 separated by the above-mentioned protective fences 1A are made available for the passage of vehicles V, and as shown in Figure 1(E), in the deck replacement method of this embodiment, the first existing deck removal process is carried out and completed, in which the existing deck slabs 21 are removed in the other lanes 51, excluding the lane 52 of the existing deck slab 22 to which the protective fence section 10A was fixed in the existing deck slab protective fence section fixing process.

[0033] Next, as shown in Figures 1(F), 3(A), 4(A), 4(B), and 4(C), in the deck replacement construction method of this embodiment, a first new deck installation process is carried out in which multiple precast decks 25 are placed in the lane 51 from which the existing deck 21 was removed in the first existing deck removal process. The first new deck installation process corresponds to the new deck installation process in the protective fence installation method of this embodiment.

[0034] As shown in Figures 1(F), 4(A), 4(B), and 4(C), in the first new slab construction process of the slab replacement construction method of this embodiment, multiple precast slabs 25 are arranged side by side with spaces between them in the direction of travel of the lane 51. As shown in Figures 3(A), 4(A), 4(B), and 4(C), in the first new slab construction process, multiple precast slabs 25 are arranged side by side with spaces between them in the direction of travel of the other lane 51, and then filler concrete 27 is poured on site between the multiple precast slabs 25.

[0035] In the first new slab construction process, when the filler concrete 27 is poured on site, a filler concrete through-hole 27h (slab through-hole 20h) is formed that passes vertically through the filler concrete 27. Therefore, similar to the above-described existing slab through-hole forming process, the first new slab construction process corresponds to the slab through-hole forming process in the protective fence installation method of this embodiment. The filler concrete through-hole 27h is formed, for example, by placing a void pipe corresponding to the shape of the filler concrete through-hole 27h as a formwork when the filler concrete 27 is poured on site. A wall parapet 43 is installed on top of the precast slab 25 and the filler concrete 27, and a pavement 28 is formed, completing the first new slab construction process.

[0036] Through the above-described first new deck construction process, a deck 23 is newly constructed in the lane 51, which has a plurality of precast decks 25 arranged at intervals in the direction of travel of the road 50 and filler concrete 27 poured on-site between the plurality of precast decks 25. Even during the first existing deck removal process, the lane 52 remains open for the passage of vehicles V.

[0037] As shown in Figures 3(B), 3(C), 4(A), 4(B), and 4(C), in the deck replacement construction method of this embodiment, a new deck slab protective fence section fixing process is carried out to fix the protective fence section 10A to the deck slab 23 newly installed in the first deck slab new installation process. Similar to the existing deck slab protective fence section fixing process described above, the new deck slab protective fence section fixing process corresponds to the protective fence section fixing process in the protective fence installation method of this embodiment.

[0038] In the new deck slab protective fence section fixing process, the fixing of the protective fence section 10A fixed to the existing deck slab 22 in the existing deck slab protective fence section fixing process by the fixing members 30 (the rods 31 and the fastening members 32) to the existing deck slab 22 is released. Specifically, the nuts which are the fastening members 32 are removed from the bolts which are the rods 31.

[0039] In the process of fixing the new deck slab protective fence section, the protective fence section 10A is moved and placed on the filler concrete 27 in which the filler concrete through hole 27h was formed in the new deck slab construction process and on the pavement 28 of the multiple precast deck slabs 25. As with the process of fixing the existing deck slab protective fence section described above, in the process of fixing the new deck slab protective fence section, the bolts, which are the rods 31, are threaded into the plate holes 13h and integrated with the protective fence section 10A, and are transported and placed by an erection machine or the like in a state where they protrude below the support base plate 13A of the protective fence section 10A.

[0040] In the new deck slab protective fence section fixing process, the protective fence section 10A is fixed onto the filler concrete 27 and the pavement 28 of the multiple precast deck slabs 25 by fixing members 30 (rods 31) inserted into the filler concrete through-holes 27h formed in the first deck slab new construction process. As with the existing deck slab protective fence section fixing process described above, in the new deck slab protective fence section fixing process, after the protective fence section 10A is placed on the deck slab 23, the protective fence section 10A is fixed to the deck slab 23 by working from the underside of the deck slab 23 and fitting fastening members 32 into the rods 31 inserted into the filler concrete through-holes 27h.

[0041] As with the existing deck slab protective fence section fixing process, in the new deck slab protective fence section fixing process, a lower plate having a contact surface that contacts the underside of the precast deck slab 25 and an insertion hole through which the rod 31 is inserted may be used to ensure a bearing area. In the new deck slab protective fence section fixing process, the lower plate may be attached to the rod 31 so that the rod 31 inserted into the fill concrete through hole 27h is further inserted into the insertion hole of the lower plate, and then fastening members 32 may be fitted to the rod 31, and the protective fence section 10A may be fixed by the fastening members 32 via the lower plate.

[0042] As with the above-described process for fixing the protective fence section to the existing deck slab, the rods 31 are inserted into the fill concrete through-holes 27h, and immediately after the protective fence section 10A is placed on the deck slab 23, and before the fastening members 32 are fitted to the rods 31, the protective fence section 10A is positioned on the deck slab 23 so as not to shift laterally. In this state, the protective fence section 10A functions as, for example, a Class A protective fence in accordance with the Ministry of Land, Infrastructure, Transport and Tourism's standards for installing protective fences. Therefore, immediately after the protective fence section 10A is placed on the deck slab 23 and before the fastening members 32 are fitted to the rods 31, the lane 51 formed by the deck slab 23 can be used for the passage of vehicles V.

[0043] As in the above-described process for fixing the protective fence to the existing deck slab, the inner diameter of the filler concrete through hole 27h is sufficiently larger than the diameter of the rod 31. When the fastening member 32 is fitted into the rod 31, it is preferable that the outer surface of the rod 31 inserted into the filler concrete through hole 27h and the inner surface of the filler concrete through hole 27h are not in contact with each other. By keeping them out of contact, when the fastening member 32 is fitted into the rod 31, the protective fence 10A is fixed and secured to the deck slab 23 by the frictional force between the support base plate 13A and the deck slab 23 (filler concrete 27).

[0044] This ensures the quality of the fill concrete 27 against traffic vibrations of the lane 51 used for the passage of vehicle V and against loads when vehicle V comes into contact with the guardrail section 10A. When the fastening members 32 are fitted into the rods 31, the guardrail section 10A functions as, for example, an SB-type guardrail in accordance with the guardrail installation standards of the Ministry of Land, Infrastructure, Transport and Tourism. After the new deck slab guardrail section fixing process, the deck slab 22 is replaced after the deck slab 21, and the newly installed deck slab 23 is used for the passage of vehicle V during the work of replacing the deck slab 22.

[0045] 4(A), 4(B), and 4(C), a guardrail fence 1A in which a guardrail fence section 10A is fixed to a newly installed deck slab 23 of this embodiment includes the deck slab 23, the guardrail fence section 10A that partitions a road 50, interfacial concrete through-holes 27h (slab through-holes 20h) that penetrate the deck slab 23 from top to bottom, and fixing members 30 (rods 31 and fastening members 32) that are inserted into the interfacial concrete through-holes 27h and fix the guardrail fence section 10A to the deck slab. The deck slab 23 has a plurality of precast decks 25 arranged at intervals in the traveling direction of the road 50 and interfacial concrete 27 poured on-site between the plurality of precast decks 25, and the interfacial concrete through-holes 27h are formed in the interfacial concrete 27.

[0046] The lane 51 defined by the above-described protective fence 1A is used for the passage of vehicles V, and as shown in Fig. 3(D), in the deck replacement method of this embodiment, after the new deck protective fence section fixing process, a second existing deck removal process is carried out to remove the existing deck slab 22 in the lane 52. Next, as shown in Fig. 3(E), the lane 51 defined by the protective fence 1A is used for the passage of vehicles V, and in the deck replacement method of this embodiment, a second new deck installation process is carried out to place multiple precast deck slabs 26 in the lane 52 from which the existing deck slab 22 was removed in the second existing deck removal process.

[0047] In the second slab construction process, as shown in FIG. 3(F), tendons 44 are inserted into holes communicating with the precast slabs 25 arranged in the first slab construction process and the precast slabs 26 arranged in the second slab construction process, and a tensioning process is performed in which the tendons 44 apply tension to the precast slabs 25 and 26. Also, in the second slab construction process, as shown in FIG. 3(G), filler concrete 27 is poured in situ between the precast slabs 26. Through the second slab construction process, a slab 24 is newly constructed in the lane 52, including the precast slabs 26 arranged at intervals in the traveling direction of the road 50 and the filler concrete 27 poured in situ between the precast slabs 26. A wall parapet 43 is installed on the slab 24, and a pavement 28 is formed on the slab 24.

[0048] 5(A) and 5(B), in the second slab new installation process, the precast slab 25 placed in the first slab new installation process and the precast slab 26 placed in the second slab new installation process may be connected by an installation jig 70 between the time the precast slab 26 is placed on the lane 52 and the time the tensioning process is completed. The installation jig 70 includes an upper abutment member 71 that abuts across the upper surfaces of the precast slabs 25 and 26, a lower abutment member 72 that abuts across the lower surfaces of the precast slabs 25 and 26, and a pair of fastening members (clamps) 73 that fasten the upper abutment member 71 and the lower abutment member 72. The erection jig 70 connects the precast deck 26 placed in the lane 52 to the precast deck 25 of the lane 51, which is in use and vibrating due to the passage of the vehicle V, until the tensioning process is completed. This makes it possible to suppress displacement of the precast decks 25, 26 and improve the accuracy of the construction.

[0049] When the precast decks 25, 26 are connected by the installation jig 70, for example, in the first deck new installation process, in order to secure space for arranging the installation jig 70, the filler concrete 27 may not be poured and the pavement 28 may not be formed in the area of the precast deck 25 100 to 200 mm inside from the boundary with the lane 52. In the new deck protective fence section fixing process, the protective fence section 10A may be fixed onto the filler concrete 27 and the pavement 28 of the multiple precast decks 25, as in Figures 4(A), 4(B), and 4(C).

[0050] 5(A) and 5(B), when the precast decks 25, 26 are connected by an erection jig 70, for example, in the first deck new construction step, in order to ensure space for arranging the erection jig 70, filler concrete 27 is not poured in the area 100 to 200 mm inside from the boundary of the precast deck 25 with the lane 52, and in order to ensure space for arranging the protective fence section 10A, pavement 28 does not have to be formed in the area 200 to 400 mm inside from the boundary of the precast deck 25 with the lane 52. In the new deck protective fence section fixing step, the protective fence section 10A is fixed via height adjustment materials 60 to the area of the precast deck slab 25 where pavement 28 is not formed so that the protective fence section 10A is at an appropriate height relative to the top surface of the pavement 28.

[0051] 6(A) and 6(B), when the precast slabs 25, 26 are connected by an erection jig 70, and in the first new slab construction step, filler concrete 27 is not poured in the area 100 to 200 mm inside from the boundary between the precast slab 25 and the lane 52, and pavement 28 is not formed in the area 200 to 400 mm inside from the boundary between the precast slab 25 and the lane 52, for example, in the new slab protective fence section fixing step, the protective fence section 10A may be fixed directly to the area of the precast slab 25 where the pavement 28 is not formed. When the protective fence section 10A is fixed directly to the area of the precast slab 25 where the pavement 28 is not formed, the height of the protective fence section 10A may be increased in accordance with the thickness of the pavement 28.

[0052] In addition, in areas of the precast deck 25 where filler concrete 27 was not poured and pavement 28 was not formed in the above-mentioned first deck construction process, filler concrete 27 will be poured in a later process and pavement 28 will be formed.

[0053] As shown in FIG. 3(G), a protective fence portion removal process is performed to remove the protective fence portion 10A from the deck slab 23. In the protective fence portion removal process, the protective fence portion 10A fixed to the deck slab 23 is released from the fixing members 30 (rods 31 and fastening members 32) between the deck slab 23 and the fixing members 30. Specifically, the nuts, which are fastening members 32, are removed from the bolts, which are rods 31. After the protective fence portion 10A is removed by an erection machine or the like, the filler concrete through-holes 27h are filled with a filler material such as mortar. The lanes 51, 52 with the newly constructed deck slabs 23, 24 are once again in use for the passage of vehicles V. In this way, the deck slab replacement method of this embodiment is completed.

[0054] Another technique for installing temporary guardrails on roads involves anchoring reinforced concrete or steel guardrails to the deck slab with anchors driven into the top surface of the deck. However, with this method, the anchors must be driven into the lane side open to vehicular traffic to prevent the guardrail from collapsing due to contact with a vehicle. Therefore, in conventional techniques, a first temporary guardrail is first placed on the existing deck slab between the lane open to vehicular traffic and the lane where traffic is restricted. Next, a second temporary guardrail, secured by anchors, is placed on the lane side of the first temporary guardrail where traffic is restricted.

[0055] At this point, traffic restrictions are placed on the lane that was open to vehicular traffic, and the lane that was previously under traffic restrictions is reopened to vehicular traffic. In this state, anchors are driven into the top surface of the deck slab on the side of the second temporary guardrail fence where traffic is restricted, and the temporary guardrail fence is fixed to the deck slab. The first temporary guardrail fence is removed. Traffic restrictions are placed again on the lane that was open to vehicular traffic on the side opposite to the side where the anchors of the second temporary guardrail fence were driven, and the lane that was previously under traffic restrictions on the side where the anchors of the second temporary guardrail fence were driven is reopened to vehicular traffic. In this state, the deck slab of the lane that was previously under traffic restrictions is replaced for the first time.

[0056] In other words, the anchors must be driven into the lane that is open to vehicular traffic, but this work requires traffic restrictions on that lane. Therefore, with conventional technology, installing a temporary guardrail requires switching between the lane that is open to vehicular traffic and the lane that is subject to traffic restrictions twice. Similarly, removing anchors driven into the lane that is open to vehicular traffic also requires switching between the lane that is open to vehicular traffic and the lane that is subject to traffic restrictions twice. Therefore, with conventional technology, removing a temporary guardrail requires switching between the lane that is open to vehicular traffic and the lane that is subject to traffic restrictions twice. Therefore, with conventional technology, the traffic restrictions associated with installing and removing a temporary guardrail are prolonged.

[0057] Furthermore, this method requires the installation of two temporary guardrails, as described above. Furthermore, the width of each individual temporary guardrail in the road width direction must be increased because the guardrail is fixed to the deck slab with anchors driven into the top surface of the deck. Therefore, this method imposes a large traffic restriction on the installation and removal of the temporary guardrail. Furthermore, this method requires drilling anchor holes into the newly installed precast deck, reducing the durability of the newly installed precast deck. Furthermore, because the temporary guardrail is fixed to the deck slab with anchors, the quality of the guardrail's anchoring portion is poor, withstanding traffic vibrations from the lane in use for vehicle traffic and the load caused by vehicle contact with the guardrail.

[0058] On the other hand, preferably according to this embodiment, a guardrail 1A that defines a road 50 formed by deck slabs 21, 22, 23, and 24 includes the deck slabs 22 and 23, a guardrail section 10A that defines the road 50, a deck slab through-hole 20h that penetrates the deck slabs 22 and 23 from top to bottom, and a fixing member 30 that is inserted into the deck slab through-hole 20h and fixes the guardrail section 10A to the deck slabs 22 and 23. The guardrail section 10A is fixed to the deck slabs 22 and 23 by the fixing member 30 that is inserted into the deck slab through-hole 20h that penetrates the deck slabs 22 and 23 from top to bottom and fixes the guardrail section 10A to the deck slabs 22 and 23. Therefore, compared to conventional technology in which a temporary guardrail is fixed to a deck slab by anchors driven into the deck slab from above, more of the work required to fix the guardrail section 10A to the deck slabs 22 and 23 can be done from the underside of the deck slabs 22 and 23. Therefore, the period of traffic control required to install the protective fence can be shortened.

[0059] Furthermore, according to this embodiment, in the deck replacement construction method, after the existing deck through-hole formation process and the existing deck protective fence fixing process, which shorten the traffic restriction period, a first existing deck removal process is carried out in which some of the lanes 52 separated by the protective fence section 10A are made available for the passage of vehicles V, while the existing deck slabs 22 in other lanes 51 are removed, and a first new deck construction process is carried out in which precast deck slabs 25 are placed in other lanes 51, thereby extending the period during which the road 50 can be made available for the passage of vehicles V.

[0060] Furthermore, according to this embodiment, in the deck replacement construction method, in the new deck slab protective fence section fixing process, the fixation by the fixing members 30 between the protective fence section 10A fixed to the existing deck slab 22 in the existing deck slab protective fence section fixing process and the existing deck slab 22 is released, and the protective fence section 10A is moved and placed to the filler concrete 27 in which the filler concrete penetration hole section 27h has been formed and the multiple precast deck slabs 25 in the new deck slab construction process, and the protective fence section 10A is fixed to the filler concrete 27 and the multiple precast deck slabs 25 by the fixing members 30 inserted into the filler concrete penetration hole section 27h formed in the new deck slab construction process, so the traffic restriction period required to move the protective fence section 10A from the existing deck slab 22 and then install it on the precast deck slab 25 can be shortened.

[0061] In addition, after the process of fixing the new deck protective fence section, which shortens the traffic restriction period, a second process of removing the existing deck 22 in lane 52 is carried out, while keeping lane 51 divided by protective fence section 10A open to vehicle traffic, and a second process of installing a new deck 26 in lane 52 are carried out, thereby extending the period during which road 50 can be used for vehicle V to pass.

[0062] Furthermore, according to this embodiment, there is no need to switch between lanes available for vehicle traffic and lanes subject to traffic restrictions in order to install and remove temporary protective fences. Therefore, according to this embodiment, the period of traffic restrictions related to the installation and removal of temporary protective fences can also be shortened during the lane switching period.

[0063] Furthermore, according to this embodiment, there is no need to install two temporary guardrails. Furthermore, the width of the guardrail section 10A in this embodiment in the width direction of the road can be narrower than that of conventional temporary guardrails because the guardrail section 10A is fixed to the deck slabs 22, 23 by the fixing members 30 inserted through the deck through-holes 20h. Therefore, according to this embodiment, the range of traffic restrictions related to the installation and removal of the temporary guardrail can be reduced.

[0064] Furthermore, according to the protective fence 1A of this embodiment, in the deck 23 having a plurality of precast decks 25 arranged at intervals in the direction of travel of the road 50 and interfacial concrete 27 poured on site between the plurality of precast decks 25, the interfacial concrete through-hole portion 27h is formed in the interfacial concrete 27, and no holes are provided in the precast decks 25 that mainly constitute the deck 23, thereby improving the durability of the deck 23.

[0065] That is, in this embodiment, no anchor holes are drilled in the newly installed precast deck 25, ensuring high durability of the newly installed precast deck 25. Also, in this embodiment, the guardrail fence section 10A is fixed to the deck 23 by the frictional force between the support base plate 13A and the deck 23. This ensures the quality of the fixed section of the guardrail fence section 10A against traffic vibrations of the lane 51 used for the passage of the vehicle V and loads when the vehicle V comes into contact with the guardrail fence section 10A.

[0066] Furthermore, in this embodiment, no work such as anchoring the deck slabs 22, 23 is required. Therefore, safety is ensured during installation and removal of the protective fence section 10A. Furthermore, in this embodiment, the protective fence section 10A is made of steel, and therefore is lighter than conventional protective fences made of reinforced concrete. Therefore, even when the protective fence section 10A is installed on the existing deck slab 22, which is divided into two parts, the existing deck slab 21 and the deck slab 22, and is in a cantilevered state, reinforcement of the existing deck slab 22 is not required, and the impact on the existing deck slab 22 can be reduced. Furthermore, the protective fence section 10A of this embodiment has a simple structure in which the protective fence section 10A is fixed to the deck slabs 22, 23 by the fixing members 30 inserted through the deck slab through-holes 20h. Therefore, it can be manufactured more inexpensively than conventional temporary protective fences.

[0067] Furthermore, according to the protective fence installation method of this embodiment, in the new slab construction step, a plurality of precast slabs 25 are arranged side by side at intervals in the direction of travel of the road 50 to replace the existing ones, and then filler concrete 27 is poured on site between the plurality of precast slabs 25. In the slab through hole formation step, when the filler concrete 27 is poured on site in the new slab construction step, filler concrete through hole portions 27h are formed in the filler concrete 27. Therefore, the pouring of the filler concrete 27 on site and the formation of the filler concrete through hole portions 27h can be performed simultaneously, making it easy to form the filler concrete through hole portions 27h.

[0068] Furthermore, according to the protective fence installation method of this embodiment, the fixing member 30 comprises a rod 31 protruding below the protective fence section 10A and a fastening member 32 that fits into the rod 31, and in the protective fence section fixing step, the rod is inserted into the deck slab through-hole 20h formed in the deck slab through-hole forming step, and the protective fence section 10A is placed on the deck slabs 22, 23. Therefore, immediately after the protective fence section 10A is placed on the deck slabs 22, 23, the protective fence section 10A is placed on the deck slabs 22, 23 so as not to shift laterally. Furthermore, in the protective fence section fixing step, the fastening member 32 is fitted into the rod 31 inserted into the deck slab through-hole 20h, thereby fixing the protective fence section 10A to the deck slabs 22, 23. Therefore, in the protective fence section fixing process, much of the work required to fix the protective fence section 10A to the deck slabs 22, 23 can be done from the underside of the deck slabs 22, 23. This makes it possible to shorten the traffic restriction period required to install the protective fence section 10A.

[0069] A safety fence according to a second embodiment of the present invention will now be described. As shown in Figures 7(A), 7(B), and 7(C), a safety fence 1B according to this embodiment includes a safety fence section 10B instead of the safety fence section 10A of the first embodiment. The safety fence section 10B includes a beam 12B that is supported from below by the upper end of a support post 11A and extends along the direction of travel of the road 50. The safety fence section 10B also includes beams 12C that extend along the direction of travel of the road 50 on the side of the support post 11A facing the lane 51 and the side of the support post 11A facing the lane 52, at two positions midway along the height of the support post 11A.

[0070] The guardrail fence section 10B has a net 18 instead of the guardrail plate 15 of the guardrail fence section 10A of the first embodiment. The net 18 is supported by the centers of the side surfaces of the support posts 11A facing the road 50 in the direction of travel and the side surfaces opposite the road 50 in the direction of travel, the centers of the undersides of the beams 12B, and the centers of the upper surfaces of the support post base plates 13A. The net 18 extends in a direction perpendicular to the upper surface of the deck slab 23 and along the road 50 in the direction of travel. The net 18 is made of metal or synthetic resin.

[0071] In this embodiment, the protective fence section 10B is provided with the net 18 instead of the protective plate 15, and therefore durability against wind loads on the road 50 can be improved.

[0072] A guardrail according to a third embodiment of the present invention will now be described. As shown in Figures 8(A), 8(B), and 8(C), a guardrail 1C according to this embodiment includes a guardrail section 10C instead of the guardrail section 10A of the first embodiment. The guardrail section 10C includes openings 16A that open near the support base plates 13A in the guardrail plates 15 on both the side of the lane 51 used for vehicle V passage and the side of the lane 52 where work to replace the deck slab 22 will be carried out.

[0073] In this embodiment, for example, in the process of fixing the newly constructed deck slab protective fence section, even if the bolt, which is the rod material 31, is not previously screwed into the plate hole portion 13h, after the protective fence section 10B is placed on the deck slab 23, a worker can reach into the opening 16A from the lane 52 side where the work of replacing the deck slab 22 is being carried out, and perform the work, thereby allowing the rod material 31 to be inserted into the plate hole portion 13h and the interfill concrete through hole portion 27h while keeping the lane 51 open for the passage of vehicles V.

[0074] 8(D), after the protective fence section 10C is placed on the deck slab 23, until the rods 31 are inserted through the plate holes 13h and the filler concrete through holes 27h, temporary reinforcement members 17 that can be moved on the deck slab 22 by casters or the like may be used to prevent the protective fence section 10C from shifting toward the deck slab 22 due to contact with a vehicle V or the like. If necessary from the standpoint of guiding a vehicle V that has come into contact with the protective fence section 10C, the opening 16A of the protective plate 15 on the side of the lane 51 used for vehicle V passage may be closed with a removable steel plate.

[0075] The protective fence section 10C of this embodiment can also be applied to the existing deck slab protective fence section fixing process. In this case, in the existing deck slab through-hole forming process, the protective fence section 10C may be shifted from its original position on the existing deck slab 22 toward the existing deck slab 21 as a Class A protective fence in the protective fence installation standards of the Ministry of Land, Infrastructure, Transport and Tourism, and then the existing deck slab through-hole 22h may be formed on the deck slab 22 side of the protective fence section 10C.

[0076] A protective fence according to a fourth embodiment of the present invention will now be described. As shown in Figures 9(A), 9(B), and 9(C), a protective fence 1D of this embodiment includes a protective fence section 10D instead of the protective fence section 10A of the first embodiment. The protective fence section 10D is made of reinforced concrete and does not include a beam 12A or a protective plate 15. The protective fence section 10D includes a support post 11B, a support post base plate 13B, a reinforcing rib 14B, and an opening 16B. The support post 11B is a steel pipe whose tip is embedded in the reinforced concrete of the protective fence section 10D. The support post base plate 13B is a steel plate similar to the support post base plate 13A of the first embodiment and includes a plate hole portion 13h. The reinforcing rib 14B is similar to the reinforcing rib 14A of the first embodiment.

[0077] The opening 16B is a through-hole portion that penetrates between the lane 51 side used for the passage of vehicles V and the lane 52 side where work to replace the deck slab 22 is being performed, near the support base plate 13B. The opening 16B performs the same function as the opening 16A in the third embodiment. As in the third embodiment, if necessary from the standpoint of guiding vehicles V that come into contact with the protective fence portion 10C, the side of the opening 16B on the lane 51 side used for the passage of vehicles V may be closed with a removable steel plate.

[0078] The guardrail fence section 10D of this embodiment is made of reinforced concrete and is heavier than the steel guardrail fence section 10A of the first embodiment. Therefore, the rods 31, which are bolts, are not threaded into the plate holes 13h in advance, and even during the period from when the guardrail fence section 10D is placed on the deck slab 23 until the rods 31 are inserted into the plate holes 13h and the filler concrete through holes 27h, the guardrail fence section 10B can be prevented from shifting toward the deck slab 22 due to contact with the vehicle V or the like, without requiring the temporary reinforcement 17 as in the second embodiment.

[0079] A guardrail and a guardrail installation method according to a fifth embodiment of the present invention will now be described. As shown in Figures 10(A), 10(B), and 10(C), a guardrail 1E according to this embodiment replaces the guardrail section 10A of the first embodiment by including a first guardrail section 10e extending along the lanes 51 and 52 of a road 50 defined by the guardrail 1E, and a second guardrail section 10E extending along the lanes 51 and 52, continuing from the first guardrail section 10e. In this embodiment, the first guardrail section 10e and the second guardrail section 10E have the same configuration.

[0080] 10(A), 10(B), 10(C), 11(A), 11(B), and 11(C), connecting portion 19A connecting first protective fence portion 10e and second protective fence portion 10E has, when viewed vertically, a convex portion 19a on one side and a concave portion 19b on the other side, and convex portion 19a and concave portion 19b can fit together. In addition, convex portion 19a and concave portion 19b have locking portions 19x and 19y that limit movement along lanes 51 and 52.

[0081] In this embodiment, the first protective fence section 10e and the second protective fence section 10E have the same configuration, and therefore the first protective fence section 10e and the second protective fence section 10E have a convex section 19a at one of the connecting sections 19A and a concave section 19b at the other connecting section 19A. Note that, for example, the first protective fence section 10e may have either the convex section 19a or the concave section 19b at both connecting sections 19A, and the second protective fence section 10E may have the other of the convex section 19a or the concave section 19b at both connecting sections 19A.

[0082] The first and second safety fence sections 10e and 10E each have a post 11C, a beam 12D, a beam 12E, and a post base plate 13C. The beam 12D is supported from below by the upper ends of the two posts 11C and extends along the direction of travel of the road 50. The beam 12E extends along the direction of travel of the road 50 at two positions midway between the heights of the two posts 11C, on the side of the post 11C facing the lane 51 and the side of the post 11C facing the lane 52. Both ends of the beams 12D and 12E are located at the same position, spaced apart from the post 11C, when viewed vertically. The post base plate 13C is a steel plate similar to the post base plate 13A of the first embodiment and includes a plate hole 13h.

[0083] The first and second safety fence sections 10e, 10E have fitting vertical members 19v at one of the connecting portions 19A. The fitting vertical members 19v extend vertically from the upper ends of the beams 12D, 12E, passing between the two upper beams 12E and between the two lower beams 12E, to the lower end of the lower beam 12E. When viewed vertically, parts of the fitting vertical members 19v protrude from the ends of the beams 12D, 12E. The parts of the fitting vertical members 19v protruding from the ends of the beams 12D, 12E form the convex portions 19a. When viewed vertically, protrusions protrude from the side of the tip of the convex portion 19a facing the lane 51 and the side of the tip of the convex portion 19a facing the lane 52. The protrusions protrude over the entire vertical range of the fitting vertical members 19v that form the convex portions 19a. The protrusions form the locking portions 19x.

[0084] The first and second safety fence sections 10e and 10E have cutouts in the beams 12D, 12E of the other connecting portion 19A that correspond to the shape of the protrusion 19a when viewed vertically. The cutouts form recesses 19b. When viewed vertically, the cutouts include a portion that is further recessed in the lateral direction intersecting the lanes 51, 52 and can accommodate the protrusion of the locking portion 19x. The portion of the cutout that is recessed in the lateral direction intersecting the lanes 51, 52 forms the locking portion 19y. The protrusion 19a and the recess 19b are composed of surfaces that extend in the vertical direction. The protrusion 19a and the recess 19b face each other so that their surfaces extending in the vertical direction are in contact with each other and are fitted together. The fitted protrusion 19a and recess 19b can slide against each other in the vertical direction and mutually restrict movement in the lateral direction intersecting the lanes 51, 52.

[0085] Locking portion 19x protrudes in a lateral direction intersecting with lanes 51 and 52. Locking portion 19y is recessed in a lateral direction intersecting with lanes 51 and 52. Locking portion 19x and locking portion 19y engage with each other, thereby restricting movement of fitted protrusion 19a and recess 19b in directions away from each other. Therefore, first protective fence portion 10e and second protective fence portion 10E are fitted to each other at connection portion 19A.

[0086] Furthermore, similar to the first embodiment, the protective fence 1E of this embodiment is provided with a deck slab through-hole 20h that passes vertically through the deck slab 23, and a fixing member 30 made of a rod 31 that protrudes downward from the first protective fence section 10e and the second protective fence section 10E, which is inserted into the deck slab through-hole 20h and fixes the first protective fence section 10e and the second protective fence section 10E to the deck slab 23. The deck slab through-hole 20h is a fill concrete through-hole 27h, similar to the protective fence 1A of the first embodiment. The protective fence 1E of this embodiment can be applied to either the deck slab 22 or the deck slab 23, similar to the protective fence 1A of the first embodiment.

[0087] 11(C), in the method for installing a guardrail fence of this embodiment, in the existing deck slab guardrail section fixing step and the new deck slab guardrail section fixing step in the deck slab replacement construction method of the first embodiment, a first guardrail section installing step is performed in which a first guardrail section 10e is installed so as to extend along the lanes 51, 52 of the road 50 partitioned by the guardrail fence 1E. In addition, a second guardrail section installing step is performed in which a second guardrail section 10E is installed so as to extend along the lanes 51, 52, continuous with the first guardrail section 10e installed in the first guardrail section installing step.

[0088] In the first protective fence section installation process and the second protective fence section installation process, the connection section 19A connecting the first protective fence section 10e and the second protective fence section 10E has a convex section 19a on one side and a concave section 19b on the other side when viewed vertically, and the first protective fence section 10e and the second protective fence section 10E are installed so that the convex section 19a and the concave section 19b are interlocked. As shown in Figure 11(C) , in the second protective fence section installation process, the convex section 19a and the concave section 19b are interlocked, and a lifting machine such as an erection machine is used to vertically lower the second protective fence section 10E installed in the first protective fence section installation process and slide it downward using the interlocked convex section 19a and concave section 19b, thereby installing the second protective fence section 10E.

[0089] In the first protective fence section installation process and the second protective fence section installation process, first protective fence section 10e and second protective fence section 10E are installed on convex section 19a and concave section 19b, having locking sections 19x, 19y that limit movement in directions along lanes 51, 52. In the second protective fence section installation process, convex section 19a and concave section 19b are fitted together while locking section 19x and locking section 19y are engaged with each other, and while restricting movement of fitted convex section 19a and concave section 19b in directions away from each other, second protective fence section 10E is slid downward relative to first protective fence section 10e installed in the first protective fence section installation process, to install second protective fence section 10E.

[0090] In the first protective fence section installation process, a first protective fence section 10e consisting of a rod 31 protruding below the first protective fence section 10e and having a fixing member 30 that fixes the first protective fence section 10e to the deck slabs 22, 23 is installed on the deck slabs 22, 23 having a deck slab through-hole 20h that penetrates the deck slabs 22, 23 from top to bottom, while the rod 31 is inserted through the deck slab through-hole 20h. In the second protective fence section installation process, a second protective fence section 20E consisting of a rod 31 protruding below the second protective fence section 10E and having a fixing member 30 that fixes the second protective fence section 20E to the deck slabs 22, 23 is installed on the deck slabs 22, 23 having a deck slab through-hole 20h while the rod 31 is inserted through the deck slab through-hole 20h.

[0091] When the first protective fence section 10e and the second protective fence section 10E are installed on the deck slab 23 newly constructed in the first protective fence section installation process and the second protective fence section installation process, in the first protective fence section installation process and the second protective fence section installation process, the first protective fence section 10e and the second protective fence section 10E are installed while inserting a rod 31 into the fill concrete through hole section 27h.

[0092] 11(C), by repeatedly installing the second protective fence section 10E by the second protective fence section installation step similar to that described above so that the second protective fence section 10E extends along the lanes 51, 52 of the road 50, contiguous to the second protective fence section 10E installed in the second protective fence section installation step, it is possible to install the first protective fence section 10e and the second protective fence section 10E that extend continuously along the lanes 51, 52 of the road 50. Note that, depending on the situation, for example, the second protective fence section 10E may be installed by the second protective fence section installation step similar to that described above between two first protective fence sections 10e that were installed along the lanes 51, 52 of the road 50 in the first protective fence section installation step, so that the second protective fence section 10E extends along the lanes 51, 52 of the road 50, contiguous to each of the first protective fence sections 10e.

[0093] According to this embodiment, the protective fence 1E that divides the road 50 formed by the deck slabs 22, 23 comprises a first protective fence section 10e that extends along the lanes 51, 52 of the road 50 divided by the protective fence 1E, and a second protective fence section 10E that extends along the lanes 51, 52, continuous with the first protective fence section 10e.The connection section 19A that connects the first protective fence section 10e and the second protective fence section 10E has a convex section 19a on one side and a concave section 19b on the other side when viewed vertically, and since the convex section 19a and the concave section 19b are interlocking, it is easy to connect the first protective fence section 10e and the second protective fence section 10E, and the traffic control period required to install the protective fence 1E can be shortened.

[0094] Furthermore, according to this embodiment, the convex portion 19a and the concave portion 19b have locking portions 19x, 19y that limit movement in the direction along the lanes 51, 52, making it easy to connect the first protective fence portion 10e and the second protective fence portion 10E, and shortening the traffic restriction period required to install the protective fence 1E.

[0095] Furthermore, according to this embodiment, the first and second protective fence sections 10e and 10E are fixed to the deck slabs 22 and 23 by fastening members 30 inserted through the deck slab through-holes 20h that penetrate the deck slabs 22 and 23. This allows more of the work required to fasten the protective fence sections to the deck slab to be performed from the underside of the deck slab, compared to conventional techniques in which temporary protective fences are fixed to the deck slab with anchors driven into the upper surface of the deck slab. This shortens the traffic restriction period required to install the protective fence. Furthermore, the first and second protective fence sections 10e and 10E are connected by fitting together at the connecting portions 19A, providing the strength to withstand the impact of vehicles straying from their lanes.

[0096] A protective fence and a protective fence installation method according to a sixth embodiment of the present invention will now be described. As shown in Figures 12(A) and 12(B), a protective fence 1F of this embodiment includes a first protective fence section 10f and a second protective fence section 10F instead of the first protective fence section 10e and the second protective fence section 10E of the fifth embodiment. In this embodiment, the first protective fence section 10f and the second protective fence section 10F have the same configuration. As shown in Figures 12(A), 12(B), 13(A), 13(B), and 13(C), a connection section 19B connecting the first protective fence section 10f and the second protective fence section 10F has a convex section 19m on one side and a concave section 19n on the other side when viewed vertically, and the convex section 19m and the concave section 19n can fit together.

[0097] Beam 12D is supported from below by the upper ends of the three pillars 11C and extends along the direction of travel of road 50. Beam 12E extends along the direction of travel of road 50 at two positions midway between the height of the three pillars 11C, on the side of pillar 11C facing lane 51 and the side of pillar 11C facing lane 52.

[0098] In this embodiment, the first protective fence section 10f and the second protective fence section 10F have the same configuration, and therefore the first protective fence section 10f and the second protective fence section 10F have a convex section 19m at one of the connecting sections 19B and a concave section 19n at the other connecting section 19B. Note that, for example, the first protective fence section 10f may have either the convex section 19m or the concave section 19n at both connecting sections 19B, and the second protective fence section 10F may have the other of the convex section 19m or the concave section 19n at both connecting sections 19B.

[0099] The first protective fence section 10f and the second protective fence section 10F have protruding portions 19m that protrude in a rectangular shape when viewed vertically at the ends of the beams 12D of one connecting section 19B. Bridging members 19p are bridged between the ends of the two upper beams 12E and the two lower beams 12E of one connecting section 19B. The first protective fence section 10f and the second protective fence section 10F have protruding portions 19m that protrude in a rectangular shape when viewed vertically at the ends of the upper and lower bridging members 19p.

[0100] Furthermore, the first protective fence section 10f and the second protective fence section 10F have recesses 19n that are rectangular in shape when viewed vertically at the ends of the beams 12D of the other connecting section 19B. Bridging members 19q are bridged between the ends of the two upper beams 12E and the two lower beams 12E of the other connecting section 19B. The first protective fence section 10f and the second protective fence section 10F have recesses 19n that are rectangular in shape when viewed vertically at the ends of the upper and lower bridging members 19q.

[0101] The protrusions 19m and recesses 19n are formed by surfaces extending in the vertical direction. The protrusions 19m and recesses 19n are opposed to each other so that their surfaces extending in the vertical direction are in contact with each other and fit together. The fitted protrusions 19m and recesses 19n can slide relative to each other in the vertical direction and mutually restrict movement in the lateral direction that intersects with the lanes 51 and 52.

[0102] Note that the convex portion 19m may protrude into a shape other than a rectangle, such as a trapezoid when viewed vertically. The concave portion 19n may be recessed into a shape other than a rectangle, such as a trapezoid when viewed vertically. The connection portion 19B formed by the convex portion 19m and the concave portion 19n in this embodiment may be formed by any of a dovetail joint, a sickle joint, a double dovetail joint, a tensioned dovetail joint, a tensioned dovetail joint, a double dovetail joint, a double dovetail joint, a cover dovetail joint, a dovetail joint, a box dovetail joint, and a four-sided sickle joint.

[0103] Furthermore, the protrusion 19m and recess 19n of this embodiment do not have locking portions 19x, 19y like the protrusion 19a and recess 19b of the fifth embodiment, but the mutually engaged protrusion 19m and recess 19n may be restricted from moving apart by any of a dovetail joint, a sickle joint, a double uneven sickle joint, a tensioned uneven dovetail joint, a tensioned uneven sickle joint, a double uneven over sickle joint, a dovetail joint, a dovetail joint, a double uneven bottom sickle joint, and a four-sided sickle joint. According to this embodiment, the connection portion 19B can be formed with a simple structure.

[0104] 13(C), the protective fence installation method of this embodiment also includes a first protective fence section installation step of installing a first protective fence section 10f and a second protective fence section installation step of installing a second protective fence section 10F, as in the fifth embodiment. In FIG. 13(C), by repeatedly installing the second protective fence section 10F so that it extends along the lanes 51, 52 of the road 50 in succession to the second protective fence section 10F installed in the second protective fence section installation step, it is possible to install the first protective fence section 10f and the second protective fence section 10F that extend continuously along the lanes 51, 52 of the road 50. Furthermore, depending on the situation, for example, a second protective fence section 10F may be installed between two first protective fence sections 10f that are installed along the lanes 51 and 52 of the road 50 at a distance corresponding to the second protective fence section 10F in the first protective fence section installation process, so as to extend along the lanes 51 and 52 of the road 50, continuous with each of the first protective fence sections 10f.

[0105] Although the present invention has been described above with reference to an embodiment, the present invention is not limited to the above embodiment and can be embodied in various forms. For example, in the above embodiment, the configurations and quantities of the beams 12A, 12B, 12C, 12D, and 12E, the reinforcing ribs 14A and 14B, the protective plate 15, the net 18, and the fixing members 30 may be changed as appropriate. [Explanation of symbols]

[0106] 1A, 1B, 1C, 1D, 1E, 1F... protective fence, 10A, 10B, 10C, 10D... protective fence section, 10e... first protective fence section, 10E... second protective fence section, 10f... first protective fence section, 10F... second protective fence section, 11A, 11B, 11C... support, 12A, 12B, 12C, 12D, 12E... beam, 13A, 13B, 13C... support base plate, 13h... plate hole section, 14A, 14B... reinforcing rib, 15... protective plate, 16A, 16B... opening, 17... temporary reinforcement material, 18... net, 19A, 19B... connection section, 19v... fitting vertical member, 19a... convex portion, 19b... concave portion, 1 9x, 19y... retaining portion, 19m... convex portion, 19n... concave portion, 19p, 19q... bridging member, 20, 21, 22, 23, 24... deck slab, 20h... deck slab penetration hole portion, 22h... existing deck slab penetration hole portion, 25, 26... precast deck slab, 27... filling concrete, 27h... filling concrete penetration hole portion, 28... pavement, 30... fixing member, 31... rod material, 32... fastening member, 41... bridge girder, 42, 43... wall parapet, 44... tension member, 50... road, 51, 52... lane, 60... height adjustment member, 70... erection jig, 71... upper abutment member, 72... lower abutment member, 73... fastening member (clamp), V... vehicle.

Claims

1. A protective fence that divides a road formed by a deck, The protective fence includes a first protective fence section extending along a lane of the road partitioned by the protective fence, and a second protective fence section extending along the lane and continuous with the first protective fence section, A protective fence in which the connection portion connecting the first protective fence portion and the second protective fence portion has a convex portion on one side and a concave portion on the other side when viewed vertically, and the convex portion and the concave portion are interlockable.

2. The safety fence according to claim 1 , wherein the protrusions and recesses have locking portions that limit movement in a direction along the lane.

3. A deck slab through-hole portion that penetrates the deck slab vertically; a fixing member consisting of a rod protruding downward from the first protective fence portion and the second protective fence portion, inserted into the deck slab through-hole portion, and fixing the first protective fence portion and the second protective fence portion to the deck slab; The protective fence according to claim 1 or 2, further comprising:

4. A method for installing a protective fence that divides a road formed by a deck, a first protective fence section installation process of installing a first protective fence section so as to extend along a lane of the road partitioned by the protective fence; a second safety fence section installation process of installing a second safety fence section so as to extend along the lane and be continuous with the first safety fence section; Equipped with A protective fence installation method in which, in the first protective fence section installation process and the second protective fence section installation process, the connection section connecting the first protective fence section and the second protective fence section has a convex section on one side and a concave section on the other side when viewed vertically, and the first protective fence section and the second protective fence section are installed so that the convex section and the concave section can be fitted together.

5. A protective fence installation method as described in claim 4, wherein in the first protective fence section installation process and the second protective fence section installation process, the first protective fence section and the second protective fence section are installed in the convex section and the concave section, respectively, having locking sections that limit movement in a direction along the lane.

6. In the first protective fence section installation step, the first protective fence section is installed on the deck slab having a deck slab through-hole section that penetrates the deck slab from top to bottom, the first protective fence section being made of a rod protruding below the first protective fence section and having a fixing member that fixes the first protective fence section to the deck slab, while the rod is inserted into the deck slab through-hole section; A method for installing a protective fence as described in claim 4 or 5, wherein in the second protective fence section installation process, the second protective fence section, which consists of a rod protruding below the second protective fence section and has a fixing member for fixing the second protective fence section to the deck slab, is installed on the deck slab having the deck slab through-hole section while inserting the rod through the deck slab through-hole section.

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