JP7625772B2 - How to build a wall parapet - Google Patents

Description

The present invention relates to a method for constructing wall parapets that are installed, for example, on the deck of a bridge.

Conventionally, bridge decks are provided with a wall balustrade, for example made of reinforced concrete, to prevent vehicles or people from falling off. This wall balustrade is constructed by erecting rebar from the ground covering at the deck side end, installing a back side formwork located on the back side of the wall balustrade on the side facing the outside of the deck, and installing a front side formwork located on the front side of the wall balustrade on the side facing the inside of the deck, and pouring concrete into these formworks (see, for example, Patent Document 1). In this case, the back side formwork and the front side formwork are connected with a gap maintained by multiple separators, and the front side formwork is supported by supports fixed to the deck by anchors.

JP 2013-57215 A

For example, in the construction of a bridge using a concrete deck, it is common to lay a waterproof layer on the concrete surface of the deck to prevent rainwater from penetrating into the concrete of the deck, and then apply asphalt or other paving on top of that, but the deck waterproofing is done after the wall parapet is constructed.

However, when constructing a wall parapet by pouring concrete on-site, as in conventional cases, construction of the deck waterproofing work cannot begin until the concrete has had time to cure and the formwork has been removed. Moreover, the time required to remove accessories such as the formwork and supports is also required before construction of the deck waterproofing work can begin, lengthening the overall construction period.

The present invention was made in consideration of the above problems, and its purpose is to provide a method for constructing a wall parapet that can shorten the overall construction period, including the construction of the wall parapet.

In order to achieve the above-mentioned objective, the method for constructing a wall balustrade of the present invention is a method for constructing a wall balustrade on a deck using wall panels made of plate-shaped concrete, in which a rear-side formwork that is placed on the rear side of the wall balustrade is installed on the outside of the deck in the width direction, and the wall panel is installed on the inside of the deck in the width direction using supports to form a front-side formwork that is placed on the front side of the wall balustrade, concrete is poured between the rear-side formwork and the wall panel, and the rear side of the wall panel is embedded in the concrete to be integrated with the concrete, and then the supports are removed before the specified concrete curing period has elapsed, and the rear-side formwork is removed after the concrete curing period has elapsed.

By doing this, the wall panel supports can be removed after the concrete has been poured and before the concrete curing period has elapsed, allowing other subsequent construction work (e.g., deck waterproofing) to begin sooner than the period between removing the supports and removing the rear formwork, without having to wait for the concrete curing period to elapse.

According to the present invention, other subsequent construction work (e.g., deck waterproofing work) can be started without waiting for the concrete curing period of the wall parapet to elapse, which shortens the overall construction period, including the construction of the wall parapet.

FIG. 1 is a perspective view of a wall balustrade showing one embodiment of the present invention. Rear view of the wall panel Side cross-sectional view of wall panel Wall panel plan Plan view of the main part showing the wall panel joining process Exploded perspective view of the support part Side cross-sectional view showing the construction process of the wall parapet Side cross-sectional view showing the construction process of the wall parapet Side cross-sectional view showing the construction process of the wall parapet Side cross-sectional view showing the construction process of the wall parapet Side cross-sectional view showing the construction process of the wall parapet Side cross-sectional view showing the construction process of the wall parapet Side cross-sectional view showing the construction process of the wall parapet Front view showing the construction process of the wall parapet Front view showing the construction process of the wall parapet Front view showing the construction process of the wall parapet A diagram showing the construction process for wall parapets and deck waterproofing

Figures 1 to 17 show one embodiment of the present invention, for example, a method for constructing a wall parapet that is installed on the deck of a bridge or the like.

The wall parapet 1 shown in the figure is made of reinforced concrete and is installed on the ground cover 3 of the deck 2 by a construction method described below. The deck 2 is made of, for example, a precast concrete deck and is erected on steel girders (not shown). The wall parapet 1 is a so-called Florida-type wall parapet, with the back surface (the surface facing the outside of the deck 2) formed vertically and the front surface (the surface facing the inside of the deck 2) slightly inclined toward the back surface from below to above (for example, inclined at an angle of 84° to the horizontal).

The pedestal 3 is constructed of concrete at the side end of the deck, with its back surface (the surface facing the outside of the deck 1) formed vertically and its front surface (the surface facing the inside of the deck 1) formed to slope downwards. In addition, the pedestal 3 is provided with reinforcing bars 4 for the wall balustrade that rise upwards from its top surface, and the top surface of the pedestal 3 is formed to form a slight downward slope (for example, 2%) toward the inside of the deck 1.

The wall railing 1 of this embodiment is constructed using a rear formwork 10 arranged on the rear side of the wall railing 1, a wall panel 20 arranged on the front side of the wall railing 1, a lower formwork 30 arranged on the lower end side of the wall panel 20, and a support 40 that supports the wall panel 20 and the lower formwork 30, and the wall panel 20 is used as a buried formwork that forms the front formwork. In addition, multiple inserts 3a for fixing the rear formwork 10 are buried in advance on the rear side of the ground covering 3, and multiple inserts 3b for fixing the support 40 are buried in advance on the front side of the ground covering 3.

The rear side formwork 10 is made of a wooden formwork formed by formwork plates 11, vertical frame members 12, and horizontal frame members 13, and its lower end is fixed to the rear of the ground covering 3. On the rear side of the rear side formwork 10, multiple single pipes 14 extending in the longitudinal direction of the wall balustrade 1 (bridge axis direction) are arranged at intervals in the vertical direction, and each single pipe 14 is attached to the formwork plates 11 and vertical frame members 12 by fixing brackets 15.

The wall panel 20 is made of a concrete plate-shaped panel body 21, a mesh-like reinforcing member 22 embedded in the panel body 21, and a connecting member 23 for connecting the panel body 21 to the concrete of the wall balustrade 1, and is manufactured in advance in a factory or the like. The panel body 21 is formed in a rectangular shape, and its upper end surface is formed in a mountain-shaped cross section so that the front half in the plate thickness direction and the back half in the plate thickness direction each have a downward slope. The back half in the plate thickness direction of the lower end surface of the panel body 21 is formed to have an upward slope, and the front half in the plate thickness direction is formed to form a surface perpendicular to the front surface of the panel body 21. In addition, the end surface on one side in the width direction of the panel body 21 and the other surface on the other side form joint surfaces 21a and 21b that are joined to the adjacent wall panel 20. Each joint surface 21a, 21b is formed so that the front half in the plate thickness direction is inclined, and the rear side in the plate thickness direction is formed so that it forms a surface perpendicular to the rear surface of the panel body 21. In this case, one inclined surface of each joint surface 21a, 21b is inclined toward the inside of the wall panel 20, and the other inclined surface is inclined toward the outside of the wall panel 20. Although not shown, the rear surface of the panel body 21 is provided with unevenness, for example, in the shape of a broom, to improve adhesion to concrete.

The reinforcing member 22 is made of a mesh-like metal plate such as an expanded metal with diamond-shaped mesh, and its surface is coated with an anticorrosive coating such as cationic electrocoating. The connecting member 23 is provided on the rear side of the wall panel 20, and is formed by arranging steel materials (e.g., channel steel materials) extending vertically and horizontally in a rectangular frame shape. The connecting member 23 is joined to the reinforcing member 22, and approximately half of the connecting member 23 in the thickness direction is embedded in the panel body 21, and the other half is exposed to the outside from the rear of the panel body 21. In addition, multiple inserts 24 are embedded in the front side of the panel body 21, and the inserts 24 are arranged in four places on both sides of the upper width direction and both sides of the lower width direction of the panel body 21.

The lower formwork 30 is made of a plate-like member, such as a long and narrow concrete panel, and is placed on the lower end side of the wall panel 20 so that its longitudinal direction (bridge axis direction) is horizontal and its thickness direction is the front-to-rear direction.

The support 40 includes a first support member 50 that supports the lower end of the wall panel 20 from the ground cover 3 side, a second support member 60 that supports the upper end of the wall panel 20 from the first support member 50 side, a third support member 70 that supports the upper end of the wall panel 20 from the rear formwork 10 side, a first connecting member 80 that connects the wall panel 20 to the first support member 50, a second connecting member 90 that connects the wall panel 20 to the second and third support members 60, 70, and a fixing member 100 that fixes the third support member 70 to the rear formwork 10.

The first support member 50 consists of a fixing part 51 fixed to the front surface of the ground cover 3, a pair of first connecting parts 52 in the width direction to which the second support member 60 is connected, a first support part 53 supporting the lower formwork 30, a second support part 54 supporting the wall panel 20, and a second connecting part 55 to which the first connecting member 80 is connected. The fixing part 51 is formed so as to be inclined at an angle equal to the front surface of the ground cover 3, and two bolt insertion holes 51a for fixing are provided at the top and bottom. Each of the first connecting parts 52 is formed so as to extend forward from both ends of the fixing part 51 in the width direction, and two bolt insertion holes 52a for connecting are provided at the top and bottom. The first support part 53 is formed in a substantially L-shape so as to support the lower end surface and front surface of the lower formwork 30, and the part supporting the front surface of the lower formwork 30 is formed so as to be inclined at an angle equal to the inclination of the front surface of the wall balustrade 1. The second support part 54 is formed to extend forward from the upper end of the first support part 53, and its upper surface is formed to form a flat surface that is long in the width direction. The second connecting part 55 is formed to extend upward from the front end of the second support part 54, and has connecting bolt insertion holes 55a at two locations in the width direction. In addition, the bolt insertion hole 55a is formed in a circle of a size that allows the bolt to move up, down, left, and right.

The second support member 60 is composed of a vertical portion 61 extending in the up-down direction and a horizontal portion 62 extending rearward from the upper end of the vertical portion 61, and the vertical portion 61 and the horizontal portion 62 are formed of a member having a U-shaped cross section. The vertical portion 61 is formed longer than the horizontal portion 62, and two bolt insertion holes 61a for connection are provided at the top and bottom of both widthwise side portions on the lower end side of the vertical portion 61, and nuts 61b that communicate with the bolt insertion holes 61a are fixed to the inner surfaces of both widthwise side portions. The horizontal portion 62 has a bolt insertion hole 62a for connection on both widthwise side portions on the rear end side, and nuts 62b that communicate with the bolt insertion hole 62a are fixed to the inner surfaces of both widthwise side portions.

The third support member 70 is composed of a horizontal portion 71 extending in the front-rear direction and a vertical portion 72 extending downward from the front end of the horizontal portion 71, with the horizontal portion 71 and vertical portion 72 being formed of a member with a U-shaped cross section. The horizontal portion 71 is formed longer than the vertical portion 72, and an engagement portion 71a is provided on the bottom surface portion at the rear end side with which the fixing member 100 engages. A bolt insertion hole 72a for connection is provided on each of the widthwise side portions on the lower end side of the vertical portion 72, and a nut 72b that communicates with the bolt insertion hole 72a is fixed to the inner surface side of each of the widthwise side portions.

The first connecting member 80 is composed of a fixing portion 81 fixed to the lower front surface of the wall panel 20, a height adjustment bolt 82 for adjusting the height position of the wall panel 20 relative to the first support member 50, a bolt mounting portion 83 to which the adjustment bolt 82 is attached, and a connecting portion 84 to which the first support member 50 is connected. The fixing portion 81 is formed to form a surface parallel to the wall panel 20, and has bolt insertion holes 81a for fixing at two locations in the width direction. The bolt mounting portion 83 is formed to extend forward from the lower end of the fixing portion 81, and has bolt insertion holes 83a for inserting the height adjustment bolt 82 at two locations in the width direction. Nuts 83b communicating with the bolt insertion holes 83a are fixed to the lower surface of the bolt mounting portion 83, and the height adjustment bolt 82 inserted from above through the bolt insertion holes 83a is screwed into the nuts 83b. The connecting portion 84 is formed to extend downward from the front end of the bolt attachment portion 83 and has a bolt insertion hole 84a for connection, and a nut 84b that communicates with the bolt insertion hole 84a is fixed to the back side.

The second connecting member 90 is composed of a fixing portion 91 fixed to the upper front surface of the wall panel 20 and a pair of connecting portions 92 in the width direction to which the second and third support members 60, 70 are connected. The fixing portion 91 is formed to form a surface parallel to the wall panel 20, and its lower end side is bent forward in an approximately L-shape. Two bolt insertion holes 91a for fixing are provided in the fixing portion 91 in the width direction, and each bolt insertion hole 91a is formed as a long hole extending in the width direction. Each connecting portion 92 is formed to extend vertically from the fixing portion 91, and is arranged inside each bolt insertion hole 91a at intervals in the width direction. Two connecting portions 92 in the upper and lower directions are provided with bolt insertion holes 92a for connecting, and each bolt insertion hole 92a is formed as a long hole extending in the vertical direction.

The fixing member 100 is composed of a pair of U-shaped side plates 101 spaced apart from each other in the width direction, an intermediate plate 102 joined to each side plate 101, and a fixing bolt 103 attached to the intermediate plate 102, and each side plate 101 is formed in a U-shape. The intermediate plate 102 is arranged inside each side plate 101, and its upper surface is formed in an L-shape so that it extends forward along the upper end side of each side plate 101. The fixing bolt 103 is inserted in the vertical direction into the upper surface of the intermediate plate 102, and the fixing bolt 103 is screwed into a nut 102a fixed to the lower surface of the upper surface of the intermediate plate 102. The lower end side of the fixing bolt 103 protrudes inside each side plate 101 and is adapted to engage with the engaging portion 71a of the third support member 70, and the engaging portion 71a has a hole with which the lower end side of the fixing bolt 103 engages.

Here, the method of constructing the wall parapet 1 in this embodiment will be described with reference to Figures 7 to 16. Note that the following description shows a case in which the wall parapet 1 is constructed after the girders 3 are formed on the deck slab 2 and reinforcing bars 4 are arranged in the girders 3.

First, as shown in Figures 7 and 8, the lower end of the rear-side formwork 10 is fixed to the rear of the ground covering 3 by fastening the single-tube pipe 14 below the rear-side formwork 10 to the insert 3a on the rear side of the ground covering 3 with the fixing bracket 15. In addition, the fixing portion 51 of the first support member 50 of the support 40 is fastened to the insert 3b on the front side of the ground covering 3 with the bolt 56, thereby fixing the first support member 50 to the front side of the ground covering 3.

Next, as shown in Figures 8, 9 and 14, the lower formwork 30 is supported by the first support part 53 of the first support member 50, and the lower end side of the wall panel 20 is supported by the second support part 54 of the first support member 50. The first connecting member 80 is fixed to the wall panel 20 in advance, and the wall panel 20 is supported by the second support part 54 via the first connecting member 80. The first connecting member 80 is fixed to the wall panel 20 by screwing the bolt 85 that passes through the fixing part 81 into the insert 24 on the front lower side of the wall panel 20. The bolt 85 is inserted into either the left or right bolt insertion hole 81a of the fixing part 81.

When the wall panel 20 is supported by the first support member 50, as shown in FIG. 14, it is temporarily placed on the first support member 50 with a gap in the width direction from the existing wall panel 20 installed on one side in the width direction. As a result, the lower end of the height adjustment bolt 82 of the first connecting member 80 abuts against the second support part 54, and the height of the wall panel 20 relative to the first support member 50 is adjusted by the height adjustment bolt 82. The height adjustment bolt 82 is inserted into either the left or right bolt insertion hole 83a of the bolt attachment part 83.

Then, as shown in Figures 14 and 15, the wall panel 20 is shifted in the width direction and the width direction end is joined to the existing wall panel 20. At this time, as shown in Figure 5(a), adhesive S (e.g., polyurethane adhesive) is applied to the joining surface 21a on one side in the width direction of one wall panel 20, and as shown in Figure 5(b), it is engaged so as to butt against the joining surface 21b on the other side in the width direction of the other wall panel 20. As a result, since the inclined surfaces of each joining surface 21a, 21b are inclined in the same direction, the relative movement of each wall panel 20 in the thickness direction is restricted by the inclined surfaces of each joining surface 21a, 21b.

Next, the bolt 57 inserted through the bolt insertion hole 55a of the second connecting portion 55 of the first support member 50 is screwed into the nut 84b of the connecting portion 84 of the first connecting member 80 to connect the first connecting member 80 to the first support member 50. At this time, since the bolt insertion hole 55a is formed larger than the outer diameter of the bolt 57, the vertical and widthwise positional deviation of the second connecting portion 55 relative to the first support member 50 is absorbed. The first support members 50 are arranged at the butt positions of the adjacent wall panels 20, and the first connecting members 80 of each wall panel 20 are connected to one first support member 50. As a result, the wall panels 20 are connected to each other by the first connecting members 80 and the first support members 50.

Next, the second connecting members 90 are fixed to the adjacent wall panels 20. The second connecting members 90 are arranged so that both widthwise ends of the fixing portion 91 span the front surface of each wall panel 20, and are fixed to each wall panel 20 by screwing the bolts 93 that pass through the bolt insertion holes 91a of the fixing portion 91 into the inserts 24 on the upper front surface side of the wall panel 20. In this way, the wall panels 20 are connected to each other by the second connecting members 90.

Next, as shown in Figs. 10 and 16, the second support member 60 is attached to the first support member 50, and the upper end side of the wall panel 20 is supported by the second support member 60. At this time, the lower end side of the second support member 60 is connected to the first support member 50 by screwing the bolt 63 inserted through the bolt insertion hole 51a of each first connecting portion 52 of the first support member 50 into the nut 61b on the lower end side of the second support member 60. In addition, the upper end side of the second support member 60 is connected to the second connecting member 90 by screwing the bolt 64 inserted through one of the bolt insertion holes 92a (lower side) of the second connecting member 90 into the nut 62b on the upper end side of the second support member 60.

Next, as shown in Figs. 11 and 16, a third support member 70 is attached to the upper end of the rear-side formwork 10, and the upper end side of the wall panel 20 is supported by the third support member 70. At this time, the upper horizontal frame member 13 of the rear-side formwork 10 and the rear end side of the third support member 70 are sandwiched by the fixing member 100, and the fixing bolt 103 is tightened to fix the third support member 70 to the upper end of the rear-side formwork 10. In addition, the bolt 73 inserted through the other bolt insertion hole 92a (upper side) of the second connecting member 90 is screwed into the nut 72b on the front end side of the third support member 70, thereby connecting the front end side of the third support member 70 to the second connecting member 90.

After the installation of the formwork is completed as described above, concrete C is poured into the space between the rear formwork 10 and the wall panel 20 as shown in FIG. 11. At that time, the connecting member 23 on the rear side of the wall panel 20 is embedded in the concrete C. After this, the support 40 is removed, leaving the rear formwork 10 and the lower formwork 30 as shown in FIG. 12. The poured concrete usually develops its strength in about one day, and the wall panel 20 embedded in the concrete C is held in place, so it is possible to remove the support 40, for example, the day after pouring. With the support 40 removed, work can be carried out in front of the wall balustrade 1, and construction of the deck waterproofing work (laying of the waterproof layer 5) can be started. Then, after a predetermined concrete curing period has passed, the rear formwork 10 and the lower formwork 30 are removed, completing the construction of the wall balustrade 1 as shown in FIG. 13. At this time, the front of the wall balustrade 1 is formed by a wall panel 20, which is embedded in the concrete C by a joining member 23, so that the wall panel 20 is firmly integrated with the concrete C. The curing period for concrete varies depending on the season (outdoor temperature) and the cement used in the concrete, but for example, it is about 5 days for normal cement.

Thus, according to this embodiment, the rear formwork 10, which is placed on the rear side of the wall balustrade 1, is installed on the outside in the width direction (perpendicular to the bridge axis) of the deck 2, and the wall panel 20 is installed on the inside in the width direction of the deck 2 by the support 40 so as to form the front formwork placed on the front side of the wall balustrade 1. Concrete C is poured between the rear formwork 10 and the wall panel 20, and the rear side of the wall panel 20 (connecting member 23) is embedded in the concrete C to be integrated with the concrete C. The support 40 is then removed before the specified concrete curing period has elapsed, and the rear formwork 10 is removed after the concrete curing period has elapsed, which allows the overall construction period, including the construction of the wall balustrade 1, to be shortened.

That is, as shown in FIG. 17, construction of the wall balustrade 1 is carried out in the following order: installation of the rear formwork 10, installation of the wall panel 20, pouring of concrete C, removal of the support 40, and removal of the rear formwork 10. In this embodiment, however, the support 40 of the wall panel 20 is removed after a time T1 has elapsed since the concrete C has been poured, and construction of the slab waterproofing work can be started earlier by the time T3 between the removal of the support 40 and the removal of the rear formwork 10, without waiting for the concrete curing period T2 to elapse.

The wall panel 20 is made of a panel material in which a mesh-like reinforcing member 22 is embedded in a plate-like formwork body 21 made of concrete, so sufficient strength can be ensured even if the thickness dimension is reduced.

Furthermore, the support 40 is equipped with first and second support members 50, 60 that support the upper and lower ends of the wall panel 20 from the ground cover 3 side, so that supports that support the formwork from above the deck as in the past are not required, and the support structure can be simplified.

The support 40 also includes a third support member 70 that supports the upper end of the wall panel 20 from the rear formwork 10, eliminating the need for a separator to connect the rear formwork and the front formwork as in the past, and offering the advantage of preventing interference between the separator and the reinforcing bars. In particular, when a communication pipe is placed inside the wall parapet 1, this is extremely advantageous in that there is no interference between the separator and the communication pipe.

Furthermore, a new wall panel 20 is temporarily placed on the support 40 at a distance in the width direction on one side of the width direction of the existing wall panel 20 supported by the support 40, and the height position of the new wall panel 20 is adjusted on the support 40 with the height adjustment bolts 82. After that, the new wall panel 20 is shifted in the width direction relative to the support 40 and joined to the width direction end of the existing wall panel 20 with adhesive S, and the new wall panel 20 is supported by the support 40. Therefore, the height of the wall panel 20 can be adjusted before joining with adhesive S, and the height adjustment work and joining work of the wall panel 20 can be performed efficiently.

The wall panels 20 are also formed so that the joint surfaces 21a, 21b at the widthwise ends of adjacent wall panels 20 engage with each other in a manner that can restrict movement of the wall panels 20 in the thickness direction, so that adjacent wall panels 20 can be joined together without causing misalignment in the thickness direction.

In the above embodiment, the first support member 50, the second support member 60, the third support member 70, the first connecting member 80, the second connecting member 90, and the fixing member 100 of the support device 40 are each configured as separate parts and assembled on-site, but at least some of these members may be configured as a single unit.

In addition, in the above embodiment, a Florida-type wall balustrade with inclined wall panels 20 was shown, but the present invention can also be applied to a straight-wall-type wall balustrade with vertical wall panels.

The above embodiment is an example of the present invention, and the present invention is not limited to the above embodiment.

1...wall balustrade, 2...floor slab, 3...ground covering, 4...reinforcing bars, 5...waterproof layer, 10...rear side formwork, 20...wall panel, 30...lower side formwork, 40...support, 50...first support member, 60...second support member, 70...third support member, 80...first connecting member, 90...second connecting member, 100...fixing member.

Claims (6)

A method for constructing a wall balustrade on a floor slab using a wall panel made of plate-shaped concrete, comprising:
A rear side formwork to be arranged on the rear side of the wall balustrade is installed on the outer side in the width direction of the floor slab,
The wall panel is installed on the inner side in the width direction of the floor slab using a support tool so as to form a front side formwork to be placed on the front side of the wall parapet,
Concrete is poured between the rear formwork and the wall panel, and the rear side of the wall panel is embedded in the concrete to integrate it with the concrete.
The support is removed before a predetermined concrete curing period has elapsed;
A method for constructing a wall parapet, comprising removing the rear formwork after a concrete curing period has elapsed.
2. The method for constructing a wall balustrade according to claim 1, characterized in that a wall panel having a mesh-like reinforcing member embedded within a panel body is used as the wall panel. The method for constructing a wall balustrade according to claim 2, characterized in that the support used is provided with support members for supporting the upper and lower ends of the wall panel. The method for constructing a wall balustrade according to claim 3, characterized in that the support member is a support device equipped with a connecting member that connects the upper end side of the wall panel and the rear side formwork above the wall balustrade. A new wall panel is temporarily placed on the support at a widthwise interval on one side of the existing wall panel supported by the support,
After adjusting the height of the new wall panel on the support,
A new wall panel is shifted in the width direction relative to the support and joined to the width direction end of the existing wall panel via an adhesive;
5. The method for constructing a wall parapet according to claim 1, 2, 3 or 4, further comprising supporting the new wall panel with a support. The method for constructing a wall balustrade as described in claim 5, characterized in that the wall panels used are wall panels in which the joint surfaces of the widthwise ends of adjacent wall panels engage with each other so as to restrict movement of the wall panels in the thickness direction.

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