JP2020159162A - Temporary structure and construction method thereof - Google Patents

Abstract

To provide a temporary structure to be a temporary bridge or pier that can reduce the period and cost for construction and dismantling.SOLUTION: A temporary structure is a temporary bridge 10 which is provided with a plurality of box-shaped bodies 1 having openings formed at least on opposite side surfaces, placed on the ground D on the bottom of the water, and containing a heavy object 5 inside thereof, a girder receiver 2 fixed to the upper surface of each of the plurality of box-shaped bodies 1, a main girder 3 fixed over the girder receiver 2, and a lining plate 4 installed on the main girder 3.SELECTED DRAWING: Figure 1

Description

The present invention relates to a temporary structure to be a temporary bridge or a temporary pier and a method for constructing the temporary structure.

When carrying out revetment work on a large river, it is necessary to install a temporary bridge that is strong enough for the construction machine to pass in order to install the construction machine in the sandbar. In addition, temporary bridges may be installed to replace bridges or to urgently build bridges damaged by floods or earthquakes. In addition, a temporary pier may be installed for construction machines, construction vehicles, workers, etc. to pass through when performing water or underwater construction. Conventionally, these temporary bridges and temporary piers have been constructed by erection of steel bridge girders and lining plates on concrete or steel piers (see, for example, Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2015-227580 Japanese Patent No. 2001-115421

However, the piers that make up the temporary bridge and temporary pier are manufactured in a shape that matches the construction site at a factory, etc., and then transported to the construction site, where the bridge girders and the like are fixed. Therefore, the period required to construct a temporary bridge or a temporary pier was long and the cost was high. Furthermore, although temporary bridges and piers are dismantled in a few months, the period required for dismantling is long and the cost is high.

In view of the above points, it is an object of the present invention to provide a temporary structure or a method for constructing a temporary bridge or a temporary pier capable of reducing the period and cost for construction and dismantling.

The temporary structure of the present invention is a temporary structure that serves as a temporary bridge or a temporary pier, and is a plurality of boxes in which openings are formed at least on opposite side surfaces, the boxes are placed on the ground of the bottom of the water, and heavy objects are housed inside. A shape, a girder holder fixed to the upper surface of each of the plurality of box-shaped bodies, a main girder fixed over the girder holder, and a lining plate installed on the main girder. It is characterized by having.

According to the temporary structure of the present invention, since a plurality of box-shaped bodies in which heavy objects are housed function as piers, the box-shaped bodies before the heavy objects are housed are conventional concrete or steel piers. In comparison with the above, it is possible to reduce the weight and thus simplify the work. This makes it possible to reduce the period and cost associated with the construction and dismantling of a temporary bridge or temporary pier.

In the temporary structure of the present invention, it is preferable that an opening is also formed on the upper surface of the box-shaped body.

In this case, a heavy object can be accommodated from the upper surface of the box-shaped body, and the accommodating work can be simplified.

Further, in the temporary structure of the present invention, the heavy object is preferably a rock or a stone.

In this case, since many gaps are formed between the rocks and stones housed inside the box-shaped body, the river bottom with the surface in which the opening of the box-shaped body is formed facing upstream and downstream. By installing it in, it is possible to suppress the obstruction of the flow of river water.

The method for constructing a temporary structure of the present invention is a method for constructing a temporary structure to be a bridge or a temporary pier, and is a step of placing a plurality of box-shaped bodies having openings formed on at least opposite side surfaces on the ground of the bottom of the water. A step of accommodating a heavy object inside the plurality of box-shaped bodies, a step of fixing a girder holder on the upper surface of each of the plurality of box-shaped bodies, and a step of fixing the main girder over the girder holders. It is characterized by including a step of installing a lining plate on the main girder.

According to the method for constructing a temporary structure of the present invention, it is possible to reduce the period and cost for constructing and dismantling a temporary bridge or a temporary pier, similarly to the above-mentioned temporary structure of the present invention.

The schematic top view of the temporary bridge which concerns on embodiment of this invention. FIG. 1 is a schematic cross-sectional view taken along the line II-II of FIG.

The temporary bridge 10 according to the embodiment of the temporary structure of the present invention will be described with reference to the drawings.

Here, the temporary bridge 10 connects the riverbank B of the large river A and the sandbank C with reference to FIG. 1, and is configured so that construction machinery such as heavy machinery can travel. The temporary bridge 10 includes a box-shaped body 1, a girder holder 2, a main girder 3, and a lining plate 4.

The box-shaped body 1 has, for example, a rectangular parallelepiped outer shape, and a plurality of box-shaped bodies 1 are installed on the ground D of the riverbed (river bed) over the erection direction of the temporary bridge 10. A large number of heavy objects 4 such as rocks and stones are housed inside the box-shaped body 1. The riverbed corresponds to the waterbed of the present invention. Further, in the drawing, the two box-shaped bodies 1 located in the central portion are installed adjacent to each other.

Here, each box-shaped body 1 has a cage-like structure in which a rod-shaped body 1a made of a steel material such as H-shaped steel located at each line segment constituting the rectangular parallelepiped is fixed by welding or a fastening structure using bolts. ing. In addition, the rod-shaped body 1a may be provided at a portion located on the diagonal line of the surface forming the outer surface of the rectangular parallelepiped for reinforcement.

Further, a net 1b in which a steel wire or the like is woven is arranged in a portion corresponding to each surface constituting the rectangular parallelepiped of each box-shaped body 1. As the box-shaped body 1, for example, a commercially available submerged basket can be used, whereby the box-shaped body 1 can be obtained at low cost.

The outer shape of the box-shaped body 1 is not limited to a rectangular parallelepiped shape, and even if it is a cylindrical shape, in addition to a polygonal pillar shape such as a triangular columnar shape or a hexagonal columnar shape, a shape asymmetrical in the vertical direction, for example, a truncated cone shape , A truncated cone shape or a shape in which a plurality of rectangular parallelepiped shapes are stacked may be used.

The box-shaped body 1 configured in this way makes it possible to prevent heavy objects 5 such as rocks and stones housed inside the box-shaped body 1 from spilling to the outside. Further, when rocks and stones are housed as heavy objects 5 inside the box-shaped body 1, the river water freely flows between the rocks and stones and also in the gaps of the net 1b, so that the flow of the river is almost blocked. I can't. The size of the mesh of the net 1b may be determined so that the heavy object 5 housed in the box-shaped body 1 does not spill to the outside, and is, for example, 1 cm or more and 5 cm or less.

In addition to rocks and stones, sand and gravel may be contained in the box-shaped 1 as a heavy object 5, but these are not preferable because they flow out when the river flow is steep. However, if a damming plate or the like is provided on the lower portion of the downstream surface of the box-shaped body 1, sand, gravel, or the like may be accommodated. Further, sand or gravel may be put in a bag-shaped body having a fine mesh made of cloth or the like, and the bag-shaped body may be housed in the box-shaped body 1.

Further, the box-shaped body 1 may contain another object as a heavy object 5 as long as it does not pollute the river environment. However, as the rocks and stones, those existing in the river on which the temporary bridge 10 is constructed or the riverbank thereof can be used, and it is not necessary to transport them from other places, which is preferable.

Further, it is preferable to provide a large opening on the upper surface of the box-shaped body 1 so that the work of accommodating the heavy object 5 can be facilitated. It is not necessary to fill the box-shaped body 1 with the heavy object 5, and it is sufficient to accommodate the heavy object 5 at least to the extent that the box-shaped body 1 does not move due to the flow of the river.

The net 1b is not limited to the one arranged on each surface of the box-shaped body 1, and it is sufficient that openings are formed at least on the upstream and downstream surfaces of the river. For example, each surface of the box-shaped body 1 may be covered with a planar body, and one or a plurality of openings may be formed in the upstream-side and downstream-side planar bodies. In this case as well, by securing a sufficient opening area, it is possible to hardly block the flow of the river.

The box-shaped body 1 in which a heavy object 5 such as a rock or a stone is housed is heavy, and the river water passes between the net 1b of the box-shaped body 1 and the heavy object 5, so that the flow of the river is greatly blocked. Not only is it unstoppable, the box-shaped body 1 is not moved by the river water and remains stationary at the initially installed position.

As a result, the box-shaped body 1 in which the heavy object 5 is housed functions as a direct foundation type pier foundation. Therefore, no work is required to provide a pile or the like to fix the box-shaped body 1 to the ground D. Further, as described above, since the river water flows through the box-shaped body 1 containing the heavy object 5 with almost no resistance, the water level difference due to the installation of the box-shaped body 1 between the upstream side and the downstream side of the river. Rarely occurs.

In addition, in order to install the box-shaped body 1 without inclining it, it is preferable to level the ground D at the bottom of the river as necessary. In this case, it is preferable to level the ground D so that at least the steel material 1a constituting the lower surface of the box-shaped body 1 is horizontal. The box-shaped body 1 is lifted by using a claim such as a crane car and installed on the ground D at a predetermined position on the riverbed.

The box-shaped body 1 may be manufactured at the construction site of the temporary bridge 10, or may be transported to the site after being manufactured at a factory or the like. At the stage of transportation, since the heavy object 5 is not housed in the box-shaped body 1, it is lightweight and easy to transport.

Further, the box-shaped body 1 can be installed and removed at a predetermined position by using a crane. When the box-shaped body 1 is installed and removed, it is not necessary to store the heavy object 5 in the box-shaped body 1, so that even a small crane can perform these operations. Further, a heavy object 5 such as a rock or a stone can be put into the box-shaped body 1 by using a hydraulic excavator or the like. As a result, it is possible to simplify the installation and removal work as compared with the case of using a concrete or steel pier.

A girder holder 2 is fixed to the upper surface of each box-shaped body 1. The girder holder 2 is made of a steel material such as H-shaped steel, and is fixed to the rod-shaped body 1a constituting the box-shaped body 1 on the upper surface of the box-shaped body 1 by using a Bulman C-shaped metal fitting. However, it may be fixed by another fixing method such as welding or a fastening structure using bolts. The girder receiver 2 may have the same configuration as that of a conventional temporary bridge or the like, which is fixed on a pier and receives a main girder.

On the plurality of girder receivers 2, main girders 3 extending in the erection direction of the temporary bridge 10 are installed so as to extend over these girder receivers 2. A plurality of main girders 3, here two main girders 3, are arranged in parallel. The main girder 3 is made of a steel material such as H-shaped steel. The main girder 3 is not limited to being provided directly on the upper surface of the girder receiver 2, and the main girder 3 may be provided above the girder receiver 2 via another member.

A plurality of lining plates 4 are laid on the main girder 3. The lining plate 4 is made of, for example, a rectangular steel plate. Further, in addition to the lining plate 4, a reinforcing material or the like may be installed on the main girder 3. The lining plate 4 is not limited to being provided directly on the upper surface of the main girder 3, and the lining plate 4 may be provided above the main girder 3 via another member.

The configuration of the main girder 3 and the lining plate 4 may be the same as that used in a conventional temporary bridge using a bridge pier made of steel or the like. Further, if necessary, an accessory such as a guardrail may be installed on the lining plate 4.

It is preferable that the attachment portion of the temporary bridge 10 is reinforced by using sandbags 6 or the like. It is not necessary if the ground of the mounting part is strong enough, but it is preferable to reinforce it because the ground is often fragile in Nakasu and other areas.

Next, a method of constructing the temporary bridge 10 according to the embodiment of the temporary structure of the present invention will be described.

In this method, a plurality of box-shaped bodies 1 are placed on the ground D at the bottom of the river, a step of accommodating a heavy object 5 inside the box-shaped objects 1, a step of accommodating the heavy object 5, or after accommodating the heavy object 5. A step of fixing the girder receiver 2 on the upper surface of each of the box-shaped bodies 1, a step of fixing the main girder 3 over the girder receiver 2, and a lining plate on the main girder 3. It has a process of installing 4. As a result, the temporary bridge 10 can be constructed.

As described above, since the temporary bridge 10 uses the box-shaped body 1 accommodating the heavy object 5 as the direct foundation type pier foundation, it is configured as compared with the case where the pier foundation is made of concrete or steel as in the conventional case. However, since the construction is simplified and the construction is facilitated, it is possible to reduce the cost and the period required for constructing and removing the temporary bridge 10. Further, since the box-shaped body 1 can be reused, it is possible to reduce the cost from this point as well.

The present invention is not limited to the temporary bridge 10 as the temporary structure specifically described in the above-described embodiment, and can be appropriately modified as long as it is within the scope of the claims.

For example, a temporary pier may be constructed as a temporary structure. In this case, the box-shaped body 1 is installed on the ground having the seabed, the lake bottom, or the riverbed as the water bottom, and the lining plate 4 is configured to protrude into the sea, the lake, or the river.

1 ... box-shaped body, 1a ... rod-shaped body, 1b ... net, 2 ... girder holder, 3 ... main girder, 4 ... lining plate, 5 ... heavy object, 6 ... sandbag, A ... river, B ... riverbank, C ... Nakashu, D ... The ground of the riverbed (water bottom).

Claims (4)

It is a temporary structure that becomes a temporary bridge or a temporary pier.
Multiple box-shaped bodies that have openings on at least opposite sides, are placed on the ground at the bottom of the water, and contain heavy objects inside.
A girder holder fixed to the upper surface of each of the plurality of box-shaped bodies,
The main girder fixed over the girder holder,
A temporary structure including a lining plate installed on the main girder. The temporary structure according to claim 1, wherein an opening is also formed on the upper surface of the box-shaped body. The temporary structure according to claim 1 or 2, wherein the heavy object is a rock or a stone. A method of constructing a temporary structure that will be a temporary bridge or a temporary pier.
The process of placing multiple box-shaped bodies with openings on at least opposite sides on the ground at the bottom of the water,
The step of accommodating a heavy object inside the plurality of box-shaped bodies, and
A step of fixing a girder holder on the upper surface of each of the plurality of box-shaped bodies,
The process of fixing the main girder over the girder holder and
A method for constructing a temporary structure, which comprises a step of installing a lining plate on the main girder.

Images