JP2024067645A - Guard fence installation structure and replacement method - Google Patents

Abstract

[Problem] To provide a mounting structure for a guard fence such as a parapet that can reduce costs and shorten construction time when replacing a guard fence such as a parapet. [Solution] The present invention is directed to a mounting structure for a guard fence for mounting a guard fence to a protruding ground cover 8 at the roadside edge. A groove-shaped ground cover cover 2 that opens downward is arranged to fit over the ground cover 8 from above, and a fixing bolt 27 passes through at least one flange of the ground cover 2 and is fixed to the ground cover 8, thereby fixing the ground cover 2 to the ground cover 8, and the lower end of a support post 3 is fixed to a web 20 of the ground cover 2, and a cross member is attached to the support post 3. [Selected drawing] Figure 1

Description

This invention relates to the mounting structure and replacement method for guardrails, etc., installed along the roadside edge of a bridge.

Bridges usually have a parapet on both sides as a protective fence. The parapets on relatively old bridges are often made of concrete, but the required strength has increased over time, and in recent years metal parapets have become the norm. Parapets have a base (foundation) of protruding guardrails that run continuously along the sides of the bridge, and are made of posts erected on the guardrails, with copings and cross beams attached to the posts.

When replacing an old type of concrete balustrade (existing balustrade) with a new type of high-strength metal balustrade (newly constructed balustrade), the existing balustrade is generally removed, leaving the ground cover in place, and after removal, the new balustrade is installed using the remaining ground cover.

On the other hand, in the case of a high-strength metal balustrade as shown in Patent Document 1 below, anchor bolts are driven into the top surface of the ground cover, and the base plate of the support is fixed to the ground cover via the anchor bolts.

In this type of metal railing, the anchor bolts must be driven deep into the ground cover to ensure sufficient strength for the railing, i.e., the mounting strength of the posts.

JP 2011-153405 A

However, when replacing an existing concrete railing with a new metal railing as shown in Patent Document 1, the bridge with the existing railing has a low ground cover height (thickness) and the rebar is also buried, so when driving the anchor bolts of the new railing into the remaining ground cover after removing the existing railing, the anchor bolts cannot be driven deep enough. For this reason, for example, after removing the existing railing, concrete is poured on top of the remaining ground cover to raise the ground cover, and the anchor bolts of the new railing are driven deep into the raised ground cover.

However, with the conventional balustrade mounting structure shown in Patent Document 1, replacing the balustrade requires pouring new concrete into the ground cover, which results in large-scale construction work, increasing costs, and requiring a curing period for the concrete, lengthening the construction period.

This invention was made in consideration of the above problems, and aims to provide a mounting structure for guardrails and other protective fences and a method for replacing guardrails and other protective fences that can reduce costs and shorten construction time when replacing guardrails and other protective fences.

To solve the above problems, the present invention provides the following:

[1] A mounting structure for a guardrail for mounting a guardrail to a protruding ground guardrail at a road edge, comprising:
A groove-shaped ground cover that opens downward is arranged in a state where the ground cover is fitted from above,
The ground cover is fixed to the ground cover by a fixing bolt penetrating at least one flange of the ground cover and fixing the ground cover to the ground cover,
The lower ends of the posts are fixed to the webs of the ground covering cover,
A protective fence mounting structure, characterized in that a cross member is attached to the support post.

[2] The mounting structure for the protective fence described in paragraph 1 above, in which the fixing bolt is provided on the inner flange of the ground cover.

[3] The mounting structure for the protective fence described in paragraphs 1 or 2 above, in which the fixing bolts are provided on both flanges of the ground cover.

[4] A mounting structure for a protective fence as described in any one of paragraphs 1 to 3 above, in which grout is filled between the ground cover and the ground cover.

[5] An anchor bolt is fixed to the web of the ground covering cover so as to protrude upward,
The support has a base plate at a lower end,
A mounting structure for a protective fence as described in any one of claims 1 to 4, wherein the support post is fixed to the ground cover by fixing the base plate via the anchor bolt.

[6] A mounting structure for a guard fence according to any one of claims 1 to 5, in which a flange accommodating recess is formed on the inner surface of the ground cover corresponding to the inner flange of the ground cover, and the inner flange of the ground cover is accommodated within the flange accommodating recess.

[7] A mounting structure for a safety fence according to any one of claims 1 to 6, in which the fixing bolt is a flat head bolt.

[8] A method for replacing a guardrail, comprising removing an existing guardrail installed on a protruding guardrail at a roadside edge, and then attaching a new guardrail to the guardrail that remains after the removal, comprising:
The new protective fence comprises a groove-shaped ground cover that opens downward, a support, and a cross member;
The ground covering cover is fitted onto the remaining ground covering from above without reinforcing the remaining ground covering,
A fixing bolt is inserted through at least one flange of the ground cover to fix the ground cover to the ground cover;
A lower end of the support is fixed to a web of the ground cover fixed to the ground cover;
A method for replacing a protective fence, characterized in that the cross member is attached to the support post.

According to the mounting structure of the guard fence of the invention [1], the anchor bolts for fixing the posts are not directly fixed to the ground cover, but the ground cover cover is fixed to the ground cover and the posts are attached to the ground cover cover. Therefore, when replacing the guard fence, after removing the existing guard fence, the guard fence can be constructed without reinforcing the remaining ground cover. In this way, reinforcement work for the ground cover is not required when replacing the guard fence, and costs can be reduced and construction time can be shortened. Furthermore, the mounting structure of the guard fence of the present invention fits the groove-shaped ground cover cover into the ground cover from above, fixes the flange of the ground cover to the ground cover with fixing bolts, and fixes the posts to the ground cover. Therefore, the posts can be firmly attached to the ground cover via the ground cover, and a guard fence with the desired strength can be reliably constructed.

According to the protective fence mounting structure of invention [2], the inner flange of the ground cover is fixed to the ground cover by a fixing bolt, so that the ground cover can be stably attached to the ground cover.

According to the protective fence mounting structure of invention [3], the flanges on both sides of the ground cover are fixed to the ground cover with fixing bolts, so that the ground cover can be fixed more firmly to the ground cover.

According to the protective fence mounting structure of invention [4], grout is filled between the ground cover and the ground cover, so that the ground cover can be attached to the ground cover more firmly.

According to the protective fence mounting structure of the invention [5], the posts are fixed via anchor bolts fixed to the ground cover, so the posts can be fixed reliably with high strength.

According to the protective fence mounting structure of the invention [6], the inner flange of the ground cover is accommodated in the flange accommodation recess provided on the inner surface of the ground cover, so that the inner flange does not protrude inward from the inner surface of the ground cover, and defects such as a reduction in width can be reliably prevented.

The mounting structure for the protective fence of invention [7] uses flat head bolts as fixing bolts, which prevents the bolt heads from protruding, and prevents problems caused by such protrusion, such as adverse effects on the width and impaired aesthetics.

The method of replacing the protective fence of invention [8], like invention [1] above, does not require reinforcement work on the remaining ground cover, which reduces costs and shortens construction time, while also ensuring the construction of a protective fence with the desired strength.

FIG. 1 is a perspective view showing a mounting structure for a safety fence according to an embodiment of the present invention. FIG. 2 is an exploded view of FIG. FIG. 3 is a side view showing the mounting structure of the protective fence according to the embodiment. FIG. 4 is an exploded view of the lower portion of FIG. FIG. 5 is a plan view showing a ground covering cover applied to the mounting structure of the safety fence according to the embodiment. FIG. 6 is a front view showing the ground covering cover according to the embodiment.

Figure 1 is a perspective view showing the mounting structure of a balustrade as a protective fence according to an embodiment of the present invention, Figure 2 is a perspective view showing the mounting structure of the balustrade in an exploded form according to the embodiment, Figure 3 is a side view showing the mounting structure of the balustrade in an exploded form according to the embodiment, Figure 4 is a side view showing the lower part of the mounting structure of the balustrade in an exploded form according to the embodiment, Figure 5 is a plan view showing a ground cover applied to the mounting structure of the balustrade in an embodiment, and Figure 6 is a front view showing the ground cover in an embodiment. In the following description, the inside of the balustrade is the road side, and the opposite is the outside. When looking at Figures 3 and 4, the right side is the inside (road side), and the left side is the outside.

As shown in these figures, the railing mounting structure of this embodiment involves removing a railing (existing railing) made of concrete or the like that was previously installed on the bridge, and then installing a new railing (new railing) 1 of this embodiment on the ground cover 8 that remains in the area where it was removed. Note that in this embodiment, when the word "railing" is simply used, it means a "new railing."

The ground cover 8 is a protruding structure that is continuously installed along both sides of the bridge and forms the base of the parapet 1.

Meanwhile, in this embodiment, the balustrade 1 includes a ground cover (ground cover plate) 2, a support 3, a coping 4, an upper cross beam (main cross beam) 5, and a lower cross beam 6. In this embodiment, the coping 4 and the cross beams 5 and 6 form a cross member.

In this embodiment, the ground cover 2 is made of cast iron. The ground cover 2 has a groove shape that opens downward, and is integral with an inner flange 21, an outer flange 22, and a web 20 that connects the upper ends of both flanges 21, 22. As described below, the ground cover 2 is configured so that it can be fitted and positioned so as to accommodate the ground cover 8 in the groove. When fitted, the inner flange 21 is positioned on the inside (road side) based on the bridge, and the outer flange 22 is positioned on the outside.

Needless to say, the ground cover 2 is not limited to being a cast iron product, but may be a press-molded product or may be made by bolting together multiple components, etc.

The dimensions (vertical dimension) of the inner flange 21 of the ground cover 2 are formed to a length corresponding to the height of the ground cover 8 from the road surface, and the dimensions of the outer flange 22 are formed to be longer than the dimensions of the inner flange 21.

The intermediate portion of the web 20 and the outer flange 22 of the ground cover 2 is thin-walled to form a recess 25.

Furthermore, the lower ends of four anchor bolts 26 are fixed to the recessed portion 25 of the web 20 by screwing or welding, etc., and these four anchor bolts 26 are arranged so as to protrude upward from the upper surface of the recessed portion 25 of the web 20.

In addition, three bolt insertion holes 23 are formed in the inner flange 21 of the ground cover 2, and three bolt insertion holes 23 are formed in the recessed portion 25 of the outer flange 22.

Meanwhile, in the area of the ground cover 8 where the ground cover 2 is attached, the area corresponding to the inner flange 21 of the ground cover 2 is formed with a flange accommodating recess 81 by chipping or other machining, while the area corresponding to the web 20 and the outer flange 22 is roughened by chipping or other machining. The depth of the flange accommodating recess 81 is set to a depth that does not damage the reinforcing bar 80 (see Figure 4) inside the ground cover 8, and is set to be approximately the same as the thickness of the inner flange 21.

In addition, drilling holes are formed on the inner and outer surfaces of the ground cover 8 in correspondence with the bolt insertion holes 23 in the flanges 21, 22 on both sides of the ground cover 2, and driving anchors (embedded nut members) 9 are driven into and fixed in the drilling holes.

The ground cover 2 is fitted from above onto the ground cover 8, so that the ground cover 2 is arranged to cover the top surface and both inner and outer surfaces of the ground cover 8. In this fitted state, the bolt insertion holes 23 of both flanges 21, 22 of the ground cover 2 are arranged to correspond to the driven anchors 9 of the ground cover 8. Furthermore, the inner flange 21 of the ground cover 2 is arranged within the flange accommodating recess 81 of the ground cover 8, so that the surface of the inner flange 21 of the ground cover 2 is arranged in approximately the same plane as the inner surface of the area of the ground cover 8 where the ground cover 2 is not attached. In other words, the inner flange 21 of the ground cover 2 is configured not to protrude inward beyond the inner surface of the ground cover 8.

In addition, a fixing bolt 27 made of a flat head bolt is inserted into the bolt insertion hole 23 of the ground cover 2 and screwed into the anchor 9 of the ground cover 8. This ensures that the ground cover 2 is firmly fixed in place while covering the ground cover 8.

The gap between the ground cover 2 and the ground cover 8 is filled with grout 91 such as epoxy resin or non-shrink mortar and hardened (see Figure 3). In this embodiment, the area of the ground cover 8 that corresponds to the ground cover 2 is formed as a rough surface or a chipped portion (flange accommodating recess 81), so that the ground cover 2 and the ground cover 2 are reliably prevented from slipping, and the grout 91 firmly bonds the ground cover 2 and the ground cover 8 together.

The support 3 comprises a support body 31 and a base plate 35 fixed to the lower end of the support body 31 by welding or the like.

The pillar body 31 is basically made of I-beam or H-beam with an I-shaped or H-shaped cross-sectional shape, and has a pair of flanges 32 arranged on the inner and outer sides, and a web 33 connecting the two flanges 32.

As shown in FIG. 3, the outer flange 32 of the upper part of the support body 31 has been removed, leaving only the inner flange 32.

The base plate 35 has four bolt insertion holes 36 formed therein corresponding to the four anchor bolts 26 of the ground cover 2.

The base plate 35 of the support 3 is placed on the web 20 of the ground cover 2 with the anchor bolts 26 of the ground cover 2 inserted into each bolt insertion hole 36 and pulled out upward. In this state, nuts 37 are fastened to each anchor bolt 26 and pressed against the base plate 35. This fixes the support 3 to the ground cover 2 with high strength.

Although not shown in the figures, in this embodiment, caps are provided to cover the anchor bolts 26 and nuts 37 exposed on the upper surface of the base plate 35, preventing deterioration of the anchor bolts 26 and nuts 37, such as rust prevention, while also improving the design.

In this way, multiple posts 3 are fixed at predetermined intervals along the ground cover 8 via the ground cover covers 2.

Between adjacent posts 3, horizontal members such as a capping 4, upper cross beam 5, and lower cross beam 6 are attached. In other words, multiple cappings 4 in the shape of round pipes or cylinders are arranged in series between each other with sleeves 41 between them, and at the sleeve connection part of the capping 4, a bolt 38 is passed through the inner flange 32 of the corresponding post 3 from the outside, and the bolt 38 is further passed through the peripheral wall of the capping 4 and screwed into the sleeve 41. In this way, the capping 4 is attached so as to span between each of the multiple posts 3.

The upper cross beam 5 and the lower cross beam 6 are also attached in the same way. That is, multiple cross beams 5, 6 are arranged in series via sleeves 51, 61, and at the sleeve connection parts of the cross beams 5, 6, bolts 38 are passed through the inner flanges 32 of the corresponding pillars 3 from the outside, and the bolts 38 are further passed through the peripheral walls of the cross beams 5, 6 and screwed into the sleeves 51, 61. In this way, the cross beams 5, 6 are attached between the multiple pillars 3.

In the balustrade mounting structure of this embodiment configured as described above, after removing the existing balustrade made of concrete or the like, the remaining ground cover 8 is subjected to simple work such as scraping without being reinforced with concrete or the like, and then the support posts 3 are attached via the ground cover 2. This eliminates the need for large-scale construction such as pouring reinforcing concrete, reducing costs and shortening the construction period by eliminating the need for a curing period for the concrete.

In addition, in the railing mounting structure of this embodiment, the groove-shaped metal ground cover 2 is fitted into the ground cover 8 from above, and both side flanges 21, 22 of the ground cover 2 are bolted and fixed to the ground cover 8 with fixing bolts 27, and the metal support pillar 3 is fixed via the anchor bolt 26 fixed to the ground cover 2, so that the ground cover 2 can be firmly attached to the ground cover 8, and the support pillar 3 can be firmly attached to the ground cover 8 via the ground cover cover 2. In this way, the support pillar 3 can be attached with sufficient mounting strength, and the railing 1 with the desired strength can be reliably constructed.

Furthermore, in this embodiment, grout 91 is filled between the ground cover 2 and the ground cover 8 and hardened, so that the ground cover 2 can be attached more firmly to the ground cover 8, and the mounting strength of the support 3 can be further improved.

The outer flange 22 of the ground cover 2 is longer than the inner flange 21 to ensure a sufficiently large contact area with the outer surface of the ground cover 8, thereby more reliably improving the mounting strength of the ground cover 2 to the ground cover 8.

In addition, in this embodiment, a flange accommodating recess 81 is formed on the inner side of the ground cover mounting area of the ground cover 8, and the inner flange 21 of the ground cover 2 is accommodated in the recess 81. This ensures that the inner flange 21 does not protrude inward from the inner side of the ground cover, that the portion of the ground cover 2 does not exceed the building limit, and that problems such as a reduction in width are reliably prevented.

In addition, in this embodiment, flat head bolts are used as the fixing bolts 27 that fix the inner flange 21 of the ground cover 2 to the ground cover 8, so the heads of these bolts 27 do not protrude inward, which avoids adverse effects such as a reduction in width and ensures good aesthetics. Furthermore, flat head bolts are also used for the fixing bolts 27 that fix the outer flange 22 of the ground cover 2 to the ground cover 8, so the heads of the bolts 27 do not protrude outward, which ensures good aesthetics.

In addition, in this embodiment, the intermediate portion of the web 20 and the outer flange 22 of the ground cover 2 is made thin, which reduces the weight accordingly, making it easier to carry in and out the ground cover 2, as well as the construction work itself.

Next, we will explain the construction procedure (replacement method) of the railing mounting structure of this embodiment for a bridge with an existing concrete railing. Note that the construction procedure in this invention is not limited to the following procedure, and any procedure may be used.

First, the existing concrete balustrade is removed while leaving the ground cover 8 in place.

Next, in the mounting area of the ground cover 2 on the remaining ground cover 8, the inner surface of the ground cover 2 is machined by chipping or other machining to form a flange accommodating recess 81, and the top surface (upper surface) and outer surface are roughened by chipping or other methods.

Next, in the mounting area of the ground cover 2 on the ground cover 8, drill holes are formed at the bolt fixing positions on both sides of the ground cover 8, and anchors 9 are driven into the drill holes to secure them in place.

Then, the ground cover 2 is fitted over the ground cover 8 from above while its inner flange 21 is placed in the flange accommodating recess 81 of the ground cover 8, so that the top surface and both the inner and outer side surfaces of the ground cover 8 are covered with the ground cover 2.

Next, the fixing bolts 27 are inserted into the bolt insertion holes 23 in the flanges 21 and 22 on both sides of the ground cover 2, and screwed into the driving anchors 9 fixed to the ground cover 8 to secure it in place.

Next, the opening of the gap between the ground cover 2 and the ground cover 8 is sealed with a sealant such as silicone or epoxy resin, and in this state, grout 91 is injected to fill the gap between the ground cover 2 and the ground cover 8.

After the grout 91 has hardened, the support pillars 3 are attached. That is, the anchor bolts 26 of the ground cover 2 are inserted into the bolt insertion holes 36 of the base plate 35 of the support pillar 3, and the base plate 35 is placed on the web 20 of the ground cover 2. In this state, the nuts 37 are fastened to the anchor bolts 26, respectively, to fix the support pillars 3 on the ground cover 2. In this way, the multiple support pillars 3 are fixed at predetermined intervals along the ground cover 8 through the ground cover 2.

Then, as described above, the coping 4, upper cross beam 5, and lower cross beam 6 can be attached between adjacent posts 3 to construct the balustrade 1 of this embodiment.

In the above embodiment, the mounting structure of the guardrail of the present invention has been described as being applied to the railing of a bridge, but the present invention is not limited to this and can also be applied to guardrails installed in locations other than the bridge.

In the above embodiment, pipe-shaped coping 4 and cross beams 5 and 6 are used as cross members, but the present invention is not limited to this. Beam-shaped guardrail components, cable (wire)-shaped cross members, etc. may also be used as cross members, and the number of cross members is not limited.

In the above embodiment, the present invention has been described as being applied to a vehicle guardrail, but the present invention is not limited to this. It can also be applied to a pedestrian/bicycle guardrail, or a vehicle guardrail that also serves as a pedestrian/bicycle guardrail.

In the above embodiment, both flanges 21, 22 of the ground cover plate 2 are fixed to the ground cover 8 by the fixing bolts 27, but this is not limited thereto. In the present invention, it is sufficient to fix at least one of the flanges of the ground cover plate 2 by the fixing bolts. When only one flange of the ground cover plate 2 is fixed to the ground cover, it is preferable to fix the inner flange to the ground cover rather than the outer flange from the viewpoint of strength.

In the above embodiment, the support pillars 3 are either I-shaped or H-shaped, but the shape of the support pillars 3 is not particularly limited in the present invention, and it is also possible to use pipe-shaped, groove-shaped (C-shaped), angle-shaped, etc.

The protective fence mounting structure of this invention can be suitably used when installing a new protective fence using the remaining ground cover after removing an existing protective fence.

1: Parapet (protective fence)
2: Ground cover 20; Web 21: Inner flange 22: Outer flange 25: Recessed portion 26: Anchor bolt 27: Fixing bolt 3: Support 31: Support body 35: Base plate 4: Capping (horizontal member)
5: Upper cross beam (cross member)
6: Lower cross beam (horizontal member)
8: Ground cover 81: Flange receiving recess 91: Grout

Claims (8)

A guardrail mounting structure for mounting a guardrail to a protruding ground guardrail at a road edge, comprising:
A groove-shaped ground cover that opens downward is arranged in a state where the ground cover is fitted from above,
The ground cover is fixed to the ground cover by a fixing bolt penetrating at least one flange of the ground cover and fixing the ground cover to the ground cover,
The lower ends of the posts are fixed to the webs of the ground covering cover,
A protective fence mounting structure, characterized in that a cross member is attached to the support post. The protective fence mounting structure according to claim 1, in which the fixing bolt is provided on the inner flange of the ground cover. The protective fence mounting structure according to claim 1, in which the fixing bolts are provided on both flanges of the ground cover. A mounting structure for a protective fence according to any one of claims 1 to 3, in which grout is filled between the ground cover and the ground cover. An anchor bolt is fixed to the web of the ground covering cover so as to protrude upward,
The support pillar has a base plate at a lower end thereof,
A mounting structure for a protective fence as described in any one of claims 1 to 3, wherein the support post is fixed to the ground cover by fixing the base plate via the anchor bolt. A mounting structure for a guard fence according to any one of claims 1 to 3, in which a flange accommodating recess is formed on the inner surface of the ground cover corresponding to the inner flange of the ground cover, and the inner flange of the ground cover is accommodated within the flange accommodating recess. A mounting structure for a safety fence according to any one of claims 1 to 3, in which the fixing bolt is a flat head bolt. A method for replacing a guard fence in which an existing guard fence installed on a protruding guard fence at a road edge is removed, and then a new guard fence is attached to the guard fence remaining after the removal, comprising the steps of:
The new protective fence comprises a groove-shaped ground cover that opens downward, a support, and a cross member;
The ground covering cover is fitted onto the remaining ground covering from above without reinforcing the remaining ground covering,
A fixing bolt is inserted through at least one flange of the ground cover to fix the ground cover to the ground cover;
A lower end of the support is fixed to a web of the ground cover fixed to the ground cover;
A method for replacing a protective fence, characterized in that the cross member is attached to the support post.

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