JP2019152025A - Construction method of box culvert, and box culvert - Google Patents

Abstract

To provide a construction method of a box culvert that can suitably construct a relatively large box culvert by using precast concrete together with cast-in-place concrete.SOLUTION: In a construction method of a box culvert A, a step for forming a side plate comprises: a side plate building unit installation step for installing side plate building units H and J at predetermined positions; and a side plate placing step that is carried out after the side plate building unit installation step and that places cast-in-place concrete in a concrete placement space in the side plate building units H and J.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a box culvert construction method and a box culvert constructed by the construction method.

  At present, there is a strong concern that the number of field workers working at construction sites will decrease due to the decline in population and the aging of the population. Recently, in order to improve productivity at construction sites, even large box culverts depend only on cast-in-place concrete that requires many workers to assemble formwork, reinforcing bars, scaffolding, temporary support works, etc. Instead, there is a growing demand for construction methods that allow the use of partially precast concrete blocks.

  However, when building a large box culvert using a plurality of precast concrete blocks, the size of the individual precast concrete blocks has to be increased, making it difficult to manufacture, transport and construct. Will face. For this reason, in the past, when constructing a large box culvert, most of the part had to depend on on-site concrete.

  In order to eliminate such problems, conventionally, a study has been made to construct a large box culvert (so-called half precast box culvert) that uses precast concrete blocks of a size that can be manufactured, transported, and constructed together with cast-in-place concrete. Has been made.

  However, when constructing a large half precast box culvert, a considerable number of small blocks of precast concrete are required. For this reason, from the stage of study, the work of loading and unloading a plurality of precast concrete blocks on the site or accurately assembling and installing the precast concrete blocks into a desired shape becomes extremely complicated. The problem was pointed out.

JP 2007-146541 A

  The present invention has been made by paying attention to the above-described circumstances, and is a box culvert that can suitably construct a relatively large box culvert by using a cast-in-place concrete together with a precast concrete member. It is to provide a construction method and a box culvert.

  That is, the present invention has the following configuration.

  The invention according to claim 1 is a box culvert provided with a bottom plate, left and right side plates standing on both ends of the bottom plate, and a top plate constructed between upper ends of the left and right side plates. In the construction method, the left and right side slabs are formed by placing a side slab concrete in a side slab construction unit and a site cast concrete placement space provided in the side slab construction unit. The side plate construction unit includes a first side plate forming member made of precast concrete, a second side plate forming member made of precast concrete, and these first side plates. A support member for supporting the first side plate forming member and the second side plate forming member, respectively, in a state in which the in-situ concrete placement space is formed between the forming member and the second side plate forming member; With The steps for forming the side plate include a side plate building unit installation step for installing the side plate building unit at a predetermined position, and after the side plate building unit installation step, the concrete arrangement of the side plate building unit. A method for constructing a box culvert, comprising: a side plate placing step for placing a cast-in-place concrete in an installation space.

  According to a second aspect of the present invention, the side plate construction unit forms the in-place concrete placement space communicating in the vertical direction, and the first side plate forming member has a plate shape and is a box 2. The method for constructing a box culvert according to claim 1, wherein the second slab forming member has a plate shape and is positioned on the inner space side of the box culvert. .

  According to a third aspect of the present invention, the side plate construction unit installation step includes a step of arranging a plurality of the side plate construction units adjacent to each other in a direction in which the internal space of the box culvert communicates, The box culvert construction method according to claim 1 or 2, wherein a reinforcing bar capable of passing through a virtual boundary line between plate construction units is disposed in the spot cast concrete placement space.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the first side plate forming member and the second side plate forming member are plate-shaped and substantially parallel to each other. It is a construction method of the box culvert described in the paragraph.

  According to a fifth aspect of the present invention, the side plate construction unit sets the lower end edge of the first side plate forming member and the lower end edge of the second side plate forming member at the same horizontal position. Item 5. A method for constructing a box culvert according to any one of Items 1 to 4.

  According to a sixth aspect of the present invention, the first and second side plate forming members or both of the first and second side plate forming members are provided with a reinforcing steel material protruding in a cantilever manner in the cast-in-place concrete placement space. Item 6. A box culvert construction method according to any one of Items 1 to 5.

  The invention according to claim 7 is the method for constructing a box culvert according to any one of claims 1 to 6, wherein the support member is made of one or a plurality of steel materials.

  According to an eighth aspect of the present invention, the side plate construction unit is supported by the support member so that a separation distance between the first side plate forming member and the second side plate forming member can be changed. The method for constructing a box culvert according to any one of claims 1 to 6.

  The invention according to claim 9 is a box culvert including a bottom plate, left and right side plates standing on both ends of the bottom plate, and a top plate constructed between upper ends of the left and right side plates. The left and right side plates are a side plate construction unit and a site-placed side plate component formed by placing the site-cast concrete in a site-placed concrete placement space provided in the side plate construction unit. The side plate construction unit is made of precast concrete and is made of a first side plate forming member, a second side plate forming member made of precast concrete, and these first side plates. A support member for supporting the first side plate forming member and the second side plate forming member, respectively, in a state in which the in-situ concrete placement space is formed between the forming member and the second side plate forming member; Has It is a Tsu box culvert.

  As described above, according to the present invention, there is provided a box culvert construction method and a box culvert capable of suitably constructing a relatively large box culvert by using a cast-in-place concrete together with a precast concrete member. can do.

The perspective view which shows one Embodiment of this invention. The front view of the side version construction unit in the embodiment. The side view of the side version construction unit in the embodiment. The top view of the side version construction unit in the embodiment. XX sectional drawing in FIG. The YY sectional view taken on the line in FIG. The typical front view for demonstrating the construction method of the box culvert in the embodiment (corner part block installation process). The typical front view explaining the construction method of the box culvert in the embodiment (bottom plate placing process, first side plate construction unit installation process). The typical front view explaining the construction method of the box culvert in the embodiment (second side plate construction unit installation process). The typical front view explaining the construction method of the box culvert in the embodiment (top plate component block installation process). The typical front view explaining the construction method of the box culvert in the embodiment (side plate placing process, top plate placing process). The top view for demonstrating the connection aspect of the front-back direction of the side plate construction unit in the embodiment. The partial front view for demonstrating an example of the usage aspect of the reinforcing bar in a side version construction unit. The partial top view for demonstrating an example of the use aspect of the reinforcing bar in a side version construction unit. The partial front view for demonstrating an example of the usage aspect of the reinforcing bar in a side version construction unit. The partial top view for demonstrating an example of the usage aspect of the reinforcing bar between the side plate construction units adjacent to the front-back direction. The front view for demonstrating an example of the connection aspect of a corner part block and a side version construction unit. The front view for demonstrating an example of the connection aspect of a side plate construction unit and a top plate component block. The perspective view which shows other one Embodiment of this invention. The top view for demonstrating the connection aspect of the front-back direction of the side plate construction unit in the embodiment. The flowchart for demonstrating an example of the construction method of a box culvert.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 12 and FIG. 21. 1 is a perspective view showing an overall outline of a large half precast box culvert A. FIG. Moreover, FIGS. 2-6 is a figure for demonstrating the 1st side version construction unit H which is a side version construction unit. 6 to 12 and FIG. 21 are diagrams for explaining a method of constructing the half precast box culvert A. FIGS. 13 to 20 show other embodiments, and will be described with reference to FIGS. 1 to 12 and FIG. 21 as appropriate to supplement the embodiments shown in FIGS.

  The large half precast box culvert A in this embodiment is made of a precast concrete member (that is, the corner block F, the outer side and inner side side plate forming members 1, 2, 5, 6 and the top. A portion formed by placing a plate-forming block L) and on-site concrete (that is, on-site bottom plate component G, first and second on-site side plate components I and K, and on-site punch The plate composition part M) is used in combination.

  In the following description, the half precast box culvert A is simply referred to as “box culvert A”.

  As shown in FIG. 1, the box culvert A includes a bottom plate B provided on the foundation E, left and right side plates C erected on both ends of the bottom plate B, and upper end portions of the left and right side plates C. And a top plate D erected.

<< Bottom B >>
The bottom plate B is located between the left and right corner block F made of precast concrete and spaced from the left and right corner block F so as to be positioned at the left and right corners of the box culvert A. And an in-situ bottom slab component G formed by placing in-situ concrete.

<Corner Block F>
The left and right corner block F is substantially L-shaped when viewed from the front. A plurality of left and right corner block F are arranged in a direction in which the internal space P of the box culvert A communicates (hereinafter referred to as “front-rear direction”). The left and right corner block F arranged in the front-rear direction are firmly connected by connecting means (not shown).

  Any connecting means for connecting the corner block F adjacent in the front-rear direction may be used. As the connecting means, for example, a mortar-filled reinforcing bar joint is provided in the corner block F, and a reinforcing bar protruded from one side is inserted into a mortar-filled reinforcing bar joint provided on the other side. The aspect to fix can be mentioned. In addition to this, as a means for connecting the corner block F adjacent in the front-rear direction, for example, a mode of connecting the corner block F adjacent in the front-rear direction using a connecting bolt and a nut as appropriate, Examples include tightening using PC steel (PC steel bar or PC steel strand).

<In-situ bottom plate component G>
The in-situ bottom slab component G is formed by placing in-situ concrete in the in-situ concrete placement space SB for the bottom slab formed between the left and right corner block F. Reinforcing bars are provided in advance in the in-place concrete placement space SB for the bottom plate.

  As shown in FIG. 17, a plurality of reinforcing bars f2 project from the left and right corner block F toward the site-placed concrete placement space SB, and are integrated with the site-placed bottom plate component G. Is planned.

<< Side version C >>
The left and right side plates C were mounted on the first side plate building unit H and the first side plate building unit H, which are side plate building units mounted on the left and right corner block F. The second side plate building unit J, which is the side plate building unit, and the first and second field cast concretes, which are the site casting concrete placement spaces provided in the first and second side plate building units H, J. It is provided with first and second on-site side plate constituting parts I and K which are on-site side-side plate constituting parts formed by placing on-site concrete in placement spaces R1 and R2. .

<First side version construction unit H>
The first side plate construction unit H is made in advance at a place different from the place where the box culvert A is constructed (for example, a factory where a precast concrete member is manufactured). The first side plate construction unit H can be transported and installed at the site where the box culvert A is constructed in a grouped form, that is, a unitized form.

  As shown in FIG. 2, the first side plate building unit H includes a side plate forming member 1 on the outer air side which is a first side plate forming member made of precast concrete and located on the outer air side of the box culvert A. The inner side side plate forming member 2 as the second side plate forming member made of precast concrete located on the inner side of the box culvert A, the outer side side plate forming member 1 and the inner side Support for mutually supporting the side plate forming member 1 on the outer air side and the side plate forming member 2 on the inner air side in a state where the first cast-in-place concrete placement space R1 is formed between the plate forming member 2 and each other. A plurality of reinforcing bars 3 as members are provided.

  The first side plate building unit H includes an outer air side plate forming member 1 and an inner air side side plate forming member 2 that is spaced apart from the outer air side side plate forming member 1. It is supported by a plurality of reinforcing bars 3. That is, the first side plate construction unit H is a unit in which the side plate forming members 1 and 2 on the outer air side and the inner air side are connected by a plurality of reinforcing bars 3 to form a unit. In other words, the first side plate building unit H is configured to be able to move the side plate forming member 1 on the outer air side, the side plate forming member 2 on the inner air side, and the plurality of reinforcing bars 3 integrally. It is a thing.

  The side plate forming member 1 on the outer air side has a plate shape. The side plate forming member 1 on the outer air side is located on the outer air side of the box culvert A, that is, on the outer side of the first on-site concrete placement space R1. Inside the side plate forming member 1 on the outer air side, a plurality of internal force distribution bars 11 configured by reinforcing bars in a manner extending in the horizontal direction are provided. An end portion of the internal force distribution bar 11 is protruded into the first spot cast concrete arrangement space R1. The side plate forming member 1 on the outer air side is provided with a plurality of reinforcing bars 12 extending in the vertical direction at predetermined locations.

  The side plate forming member 2 on the inner air side has a plate shape. The side plate forming member 2 on the inner air side is located on the inner air side of the box culvert A, that is, on the inner side of the first on-site concrete placement space R1. Inside the side plate forming member 2 on the inner air side, a plurality of internal force distribution bars 21 configured by reinforcing bars in a manner extending in the horizontal direction are provided. An end portion of the internal force distribution bar 21 protrudes into the first spot cast-in concrete arrangement space R1. The side plate forming member 2 on the inner air side is provided with a plurality of reinforcing bars 22 extending in the vertical direction at predetermined locations. The inner side side plate forming member 2 is formed with a plurality of reinforcing bar insertion holes 23 penetrating in the thickness direction of the inner side side plate forming member 2. In addition, a recessed portion 24 in which a mounting seat for the outer nut n2 is formed is provided at a position continuous with the reinforcing bar insertion hole 23 on the outer surface side (side facing the inner space P) of the side plate forming member 2 on the inner air side. ing.

  The outer side and inner side side plate forming members 1 and 2 in the first side plate building unit H are set to have substantially the same size. Further, the side plate forming members 1 and 2 on the outer air side and the inner air side are in an upright posture and are arranged so as to be substantially parallel to each other. The side plate forming members 1 and 2 on the outer air side and the inner air side have lower end edges 1e and 2e set at the same horizontal position. In other words, the lower end edges 1e and 2e of the side plate forming members 1 and 2 on the outer air side and the inner air side are set at the same height position.

  The first cast-in-place concrete placement space R1 is formed between the side plate forming members 1 and 2 on the outer air side and the inner air side. In other words, the first side plate construction unit H forms a first on-site concrete placement space R1 that communicates in the vertical direction and the front-rear direction.

  As shown in FIGS. 5 and 6, the plurality of reinforcing bars 3 as support members can support the outer side side plate forming member 1 and the inner side side plate forming member 2 in a separated state. is there. The end portions 31 of the plurality of reinforcing bars 3 are embedded so as not to move with respect to the outer side side plate forming member 1. On the other hand, thread grooves 321 are formed in the end portions 32 of the plurality of reinforcing bars 3. Then, the end portions 32 of the plurality of reinforcing bars 3 are inserted into the plurality of reinforcing bar insertion holes 23 provided in the side plate forming member 2 on the inner air side, and are predetermined by the inner nut n1 and the outer nut n2. It is attached to the position. That is, the plurality of reinforcing bars 3 are configured such that their attachment positions can be adjusted with respect to the side plate forming member 2 on the inner air side. In other words, the first side plate building unit H is supported by the plurality of reinforcing bars 3 so that the distance between the side plate forming members 1 and 2 on the outer air side and the inner air side can be changed. .

  As shown in FIGS. 8 and 9, the corner block F and the first side plate construction unit H are firmly connected by a connecting means (not shown). Any connecting means may be used for connecting the corner block F adjacent in the vertical direction to the first side plate construction unit H. As the connecting means, for example, as shown in FIG. 17, a mortar filling type reinforcing bar joint tt is provided at the lower end of the outer side and inner side side plate forming members 1 and 2 in the first side plate construction unit H. A mode in which the reinforcing bar f3 projecting upward from the corner block F is inserted into the mortar filling type reinforcing bar joint tt and then the non-shrinking mortar is fixed by pouring into the mortar filling type reinforcing bar joint tt. Can be mentioned. As other connecting means between the corner block F and the first side plate construction unit H adjacent in the vertical direction, for example, the corner block F and the first side plate are appropriately used by using connecting bolts and nuts as appropriate. Examples include an aspect in which the building unit H is connected, and an aspect in which the construction unit H is fastened using a PC steel material (PC steel bar or PC steel strand).

<First on-site striking plate component I>
The first in-situ side slab component I is formed by placing in-situ concrete in the first in-situ concrete placement space R1 formed in the first side slab construction unit H. .

  In addition, as shown in FIG. 12, in the first on-site concrete placement space R1, before the on-site concrete is placed, the outer air side and inner air side side plates connected in the front-rear direction are provided. External force distribution bars 4a and 4b extending in the horizontal direction along the forming members 1 and 2 are disposed.

  The external force distribution bars 4a along the outer side side plate forming member 1 are disposed in the front-rear direction, and end portions 111 of the internal force distribution bars 11 projecting into the first on-site concrete placement space R1. Is supported in a predetermined manner. The external force distribution bars 4b along the side plate forming member 2 on the inner air side protrude into the first cast-in-place concrete placement space R1 in the first side plate building unit H continuously provided in the front-rear direction. The end portion 211 of the internal force distribution bar 21 is supported by a predetermined method. After the external force distribution bars 4a and 4b are set at predetermined positions, the cast-in-place concrete is placed in the first cast-in-place concrete placement space R1, and the first cast-in-place plate component I is formed. It will be.

  By the way, the external force distribution bars 4a and 4b only need to be disposed at predetermined positions along the side plate forming members 1 and 2 on the outer air side and the inner air side, respectively. For this reason, it does not need to take the aspect connected to the internal force distribution bars 11 and 12 as mentioned above.

  For example, as shown in the example of FIG. 20, the first on-site concrete placement space R <b> 1 or the second on-site concrete placement space R <b> 2 of the side plate forming members 1 and 2 on the outer air side and the inner air side is respectively provided. You may make it provide the support means sh which can support the external force distribution muscle 4a, 4b from the lower side at least. The support means sh shown in FIG. 20 is a hook that protrudes in an L shape toward the first spot-cast concrete placement space R1. The support means sh only needs to be able to support the external force distribution bars 4a and 4b. For example, the support means sh may be a hook-like one protruding obliquely toward the first spot-cast concrete placement space R1.

  If the support means sh as described above is used for the external force distribution bars 4a and 4b, the temporary fixing work by the worker is unnecessary, so the side plate forming members 1 on the outer air side and the inner air side, The external force distribution muscles 4a and 4b can be set relatively easily at predetermined positions along the line 2.

  For example, if the external force distribution bars 4a and 4b are inserted from the wife side (small edge side), that is, the front side or the back side, and the external force distribution bars 4a and 4b are placed on the support means sh, the first It is possible to arrange the external force distribution bars 4a and 4b at predetermined positions without the need for an operator to enter the on-site concrete placement space R1.

<Second side construction unit J>
The second side plate construction unit J is disposed on the first side plate construction unit H. Regarding the connection mode between the plurality of reinforcing bars 7 and the outer side and inner side side plate forming members 5 and 6 in the second side plate building unit J, basically, the plurality of reinforcing bars 7 in the first side plate building unit H This is the same as the connection mode between the reinforcing bar 3 and the side plate forming members 1 and 2 on the outer air side and the inner air side.

  The outer side side plate forming member 5 in the second side plate building unit J is disposed on the outer side side plate forming member 1 in the first side plate building unit H. The inner side side plate forming member 6 in the second side plate building unit J is disposed on the inner side side plate forming member 2 in the first side plate building unit H. The second on-site concrete placement space R2 in the second side plate construction unit J is disposed on the first on-site concrete placement space R1 in the first side plate construction unit H.

  Compared with the first side plate building unit H, the second side plate building unit J has a height dimension of the side plate forming member 5 on the outer air side that is the height of the side plate forming member 6 on the inner air side. It differs in that it is set longer than the dimensions.

  The second side plate construction unit J is made in advance at a place different from the place where the box culvert A is constructed (for example, a factory where a precast concrete member is manufactured). Then, the second side plate construction unit J can be transported to and installed at the site where the box culvert A is constructed in a grouped form, that is, a unitized form.

  The second side plate building unit J includes an outer side side plate forming member 5 which is a first side plate forming member made of precast concrete located on the outer side of the box culvert A, and an inner space of the box culvert A. Between the inner side side plate forming member 6 which is a second side plate forming member made of precast concrete located on the side, and between the outer side side plate forming member 5 and the inner side side plate forming member 6 A plurality of reinforcing bars 7 as supporting members for supporting the outer side side plate forming member 5 and the inner side side plate forming member 6 with each other in a state in which the second cast-in-place concrete placement space R2 is formed It has.

  The second side plate building unit J includes a side plate forming member 5 on the outer air side and a side plate forming member 6 on the inner air side spaced apart from the side plate forming member 5 on the outer air side. It is supported by a plurality of reinforcing bars 7. That is, the second side plate construction unit J is a unit in which the outer side and inner side side plate forming members 5 and 6 are connected by a plurality of reinforcing bars 7 to form a unit. In other words, the second side plate construction unit J is configured to be able to integrally move the outer side side plate forming member 5, the inner side side plate forming member 6, and the plurality of reinforcing bars 7. It is a thing.

  The side plate forming member 5 on the outer air side has a plate shape. The side plate forming member 5 on the outer air side is located on the outer air side of the box culvert A, that is, outside the second cast-in-place concrete placement space R2. Inside the side plate forming member 5 on the outer air side, a plurality of internal force distribution bars 11 configured by reinforcing bars in a manner extending in the horizontal direction are provided. The end of the internal force distribution bar 11 protrudes into the second spot cast concrete arrangement space R2. The outer side side plate forming member 5 is provided with a plurality of reinforcing bars 12 extending in the vertical direction at predetermined locations. The reinforcing bar 12 is for securing the rigidity of the outer side side plate forming member 5.

  The outer air side plate forming member 5 has an extended portion 5 n extending upward from the inner air side side plate forming member 6. Between the extended portions 5n of the outer side side plate forming members 5 arranged on the left and right sides, a top-cast concrete placement space SD for forming the top plate D is formed.

  The upper end surface 5m of the outer side side plate forming member 5 in the second side plate constructing unit J is set at substantially the same height as the upper end surface M1 of the on-site punching plate forming part M. That is, the upper end surface 5m of the outer side side plate forming member 5 and the upper end surface M1 of the on-site top plate forming portion M are substantially flush with each other. The inner side side plate forming member 6 and the upright portion L1 of the top plate constituting block L are firmly connected by a connecting means (not shown).

  As shown in FIG. 18, from the upper part of the outer side side plate forming member 5 (the portion located above the inner side side plate forming member 6), the standing portion L1 or the on-site cast concrete arrangement for the top plate is arranged. A plurality of reinforcing bars f4 project from the installation space SD.

  The side plate forming member 6 on the inner air side has a plate shape. The side plate forming member 6 on the inner air side is located on the outer air side of the box culvert A, that is, on the inner side of the second on-site concrete placement space R2. Inside the side plate forming member 6 on the inner air side, a plurality of internal force distribution bars 21 configured by reinforcing bars in a manner extending in the horizontal direction are provided. An end portion of the internal force distribution bar 21 is projected into the second cast-in-place concrete placement space R2. The inner side side plate forming member 6 is provided with a plurality of reinforcing bars 22 extending in the vertical direction at predetermined locations. The inner side side plate forming member 6 is formed with a plurality of reinforcing bar insertion holes 23 penetrating in the plate thickness direction of the inner side side plate forming member 6. In addition, a recessed portion 24 in which a mounting seat for the outer nut n2 is formed is provided at a position continuous to the reinforcing bar insertion hole 23 on the outer surface side (side facing the inner space P) of the side plate forming member 6 on the inner air side. ing.

  The outer side side plate forming member 5 in the second side plate building unit J has a vertical dimension longer than that of the inner side side plate forming member 6. Further, the side plate forming members 5 and 6 on the outer air side and the inner air side are each in an upright posture and are arranged so as to be substantially parallel to each other. The side plate forming members 5 and 6 on the outer air side and the inner air side have lower end edges 5e and 6e set at the same horizontal position. In other words, the lower end edges 5e and 6e of the side plate forming members 5 and 6 on the outer air side and the inner air side are set at the same height position.

  The second cast-in-place concrete placement space R2 is formed between the side plate forming members 5 and 6 on the outer air side and the inner air side. In other words, the second side plate construction unit J forms a second on-site concrete placement space R2 that communicates in the vertical direction and the front-rear direction.

  The plurality of reinforcing bars 7 as support members can support the outer side side plate forming member 5 and the inner side side plate forming member 6 in a separated state. The end portions 31 of the plurality of reinforcing bars 7 are embedded so as not to move with respect to the outer side side plate forming member 5. On the other hand, thread grooves 321 are formed in the end portions 32 of the plurality of reinforcing bars 7. The end portions 32 of the plurality of reinforcing bars 3 are inserted into the plurality of reinforcing bar insertion holes 23 provided in the side plate forming member 6 on the inner side, and are predetermined by the inner nut n1 and the outer nut n2. Is attached in position. That is, the plurality of reinforcing bars 7 are configured such that their attachment positions can be adjusted with respect to the inner side side plate forming member 6. In other words, the second side plate construction unit J is supported by the plurality of reinforcing bars 7 so that the distance between the outer side and inner side side plate forming members 5 and 6 can be changed. .

  The first side plate construction unit H and the second side plate construction unit J are firmly connected to each other by a connecting means. Any connecting means for connecting the first side plate building unit H and the second side plate building unit J adjacent in the vertical direction may be used. As the connecting means, for example, as shown in FIG. 17 and FIG. 18, a mortar-filling type reinforcing bar joint is provided at the lower end portions of the outer side and inner side side plate forming members 5 and 6 in the second side plate building unit J. tt is provided, and the reinforcing bar f5 projecting upward from the first side plate construction unit H is inserted into the mortar filling type reinforcing bar joint tt, and then the non-shrink mortar is poured into the mortar filling type reinforcing bar joint tt. The aspect fixed by this can be mentioned. As another connection means of the 1st side plate construction unit H and the 2nd side plate construction unit J which adjoin the up-down direction, for example, the aspect connected using a connection bolt and a nut suitably, PC steel materials ( A mode of tightening using a PC steel rod or a PC steel strand) can be given.

<Second on-site striking plate component K>
The second on-site strike side plate component K is formed by placing on-site cast concrete in the second on-site cast concrete arrangement space R2 formed in the second side plate construction unit J. .

  In addition, in the second on-site concrete placement space R2, before the on-site concrete is placed, the outer air side and the inner air side side plate forming members 5 and 6 that are continuously provided in the front-rear direction are provided. In addition, external force distribution bars (not shown) extending in the horizontal direction are disposed. The configuration of the external force distribution bars is the same as the description of the first side plate construction unit H shown in FIG.

<< top version D >>
The top plate D includes a top plate constituting block L made of precast concrete installed between second side plate building units J arranged on the left and right sides, an upper side of the top plate constituting block L, and a second side plate. On-site strike formed by placing cast-in-place concrete in the cast-in-place concrete placement space SD for the top plate formed between the extended portions 5e of the side plate forming member 5 on the outer air side in the construction unit J. And a plate component M.

<Top plate building block L>
The top plate constituting block L is composed of an upright portion L1 erected on the inner side side plate forming member 6 in the second side plate construction unit J and a horizontal portion L2 connecting between the upper end portions of the upright portions L1. It forms a downward U-shape with and.

  As shown in FIG. 18, a reinforcing bar f <b> 6 that extends substantially horizontally toward the side plate forming member 5 on the outer air side protrudes from the standing portion L <b> 1. Further, a reinforcing bar f7 is erected on the horizontal portion L2 toward the spot cast concrete placement space SD for the top plate. At the corner that becomes the boundary between the upright portion L1 and the horizontal portion L2, one end projects into the spot cast concrete placement space SD for the top plate, and the other end projects into the second spot cast concrete placement space R2. An inclined reinforcing bar f8 is embedded.

  The top plate constituting block L is placed on the upper end surface of the inner side side plate forming member 6 in the second side plate building unit J disposed on the left and right. In other words, the top plate constituting block L is constructed between the upper end portions of the inner side side plate forming members 6 in the second side plate constituting units J arranged on the left and right. A plurality of top plate constituting blocks L are arranged in the front-rear direction. A plurality of the top plate constituting blocks L arranged in the front-rear direction are firmly connected by a connecting means.

  Any connecting means for connecting the top plate constituent blocks L adjacent in the front-rear direction may be used. As the connecting means, for example, a mortar-filled reinforcing bar joint is provided in the top plate constituting block L, and a reinforcing bar protruded from one side is inserted into a mortar-filled reinforcing bar joint provided on the other side. The aspect to fix can be mentioned. In addition to this, as a connecting means between the top plate constituent blocks L adjacent in the front-rear direction, for example, a mode in which the top plate constituent blocks L adjacent in the front-rear direction are connected appropriately using a connecting bolt and nut, Examples include tightening using PC steel (PC steel bar or PC steel strand).

  The top plate constituting block L and the inner side side plate forming member 6 in the second side plate building unit J are firmly connected by a connecting means. Any connecting means may be used for connecting the top plate constituting block L adjacent in the vertical direction and the side plate forming member 6 on the inner side. As the connecting means, for example, as shown in FIG. 18, a mortar-filled reinforcing bar joint tt is provided inside the top plate constituting block L (the lower end portion of the upright portion L1), and the mortar-filled reinforcing bar joint tt The aspect which fixes by inserting the reinforcing bar f9 protruded upward from the side plate construction unit J, and pouring a non-shrink mortar in the mortar filling type reinforcing steel joint tt can be mentioned. As other connecting means between the top plate constituent block L adjacent in the vertical direction and the side plate forming member 6 on the inner side, for example, a connecting bolt and a nut are appropriately used to connect the top plate constituent block L and the inner side side plate forming member 6 to each other. Examples include a mode in which the side plate forming member 6 is connected and a mode in which the side plate forming member 6 is fastened using a PC steel material (PC steel bar or PC steel strand).

<Site-cutting top plate component M>
The on-site top plate constituent part M is formed by placing on-site concrete in the on-site concrete placement space SD for the top plate. In addition, in the spot cast concrete arrangement space SD for the top plate, a reinforcing bar f7 erected from the top plate constituting block L and other reinforcing bars are arranged.

  Further, a reinforcing bar f4 extending in the horizontal direction from the side plate forming member 5 on the outer side in the second side plate construction unit J toward the spot-casting concrete arrangement space SD for the top plate is projected, Integration with the on-site top plate component M is achieved.

<< Method for constructing box culvert A >>
Next, a method for constructing the box culvert A in this embodiment will be described with reference to FIGS. 7 to 12 and FIG. 21 which is a flowchart.

  The construction method of the box culvert A in this embodiment includes a step for forming the bottom plate B, a step for forming the side plate C, and a step for forming the top plate D.

  The steps for forming the bottom plate B include a corner block installation step s1 for installing the corner block F at a predetermined position on the foundation E, as shown in FIGS. After the corner block installation step s1 is completed, a bottom slab placing step s2 for placing the cast-in-place concrete in the spot-casting concrete placement space SB for the bottom slab formed between the corner block F is provided. .

  In the corner block installation step s1, a plurality of corner blocks F arranged in the front-rear direction are firmly connected by a connecting means (not shown). Before the bottom slab placing step s2 is executed, the steel slab f2 projecting from the corner block F is placed in the bottom-placed concrete placement space SB for the bottom slab formed between the left and right corner block F. Other reinforcing bars (not shown) are arranged in an appropriate manner.

  As shown in FIGS. 8, 9, 11, and 21, the process for forming the side plate C is performed by placing the first side plate building unit H on a predetermined position, that is, on the corner block F. The first side plate construction unit installation step s3 to be installed and the second side plate construction unit J to be installed on the first side plate construction unit H after the first side plate construction unit installation step s3 is completed. After the second side plate building unit installation step s4 and the second side plate building unit installation step s4 are completed, the first and second on-site concrete placements in the first and second side plate building units H and J are arranged. And a side plate placing step s5 for placing on-site concrete in the spaces R1 and R2.

  In this embodiment, the side plate placing step s5 is performed after completing the top plate constituting block installation step s6 described later. That is, as shown in FIG. 10, after the top plate constituting block installation step s6 is completed, as shown in FIG. 11, the first and second on-site concrete placement spaces R1, R2, and the top plate The cast-in-place concrete is continuously put into the cast-in-place concrete placement space SD.

  The side plate building unit installation step, that is, the first and second side plate building unit installation steps s3 and s4 include a step of arranging a plurality of first and second side plate building units H and J adjacent in the front-rear direction. Is included.

  Here, as shown in FIG. 12, when the cast-in-place concrete is placed in the first cast-in-place concrete placement space R1, the external force distribution bars arranged in the first cast-in-place concrete placement space R1. The state where 4a, 4b and the internal force distribution muscles 11, 21 provided in the first side plate construction unit H are substantially connected is constructed. In other words, in the first and second side plate construction unit installation steps s3 and s4, the external power distribution that is a reinforcing bar that can pass through the virtual boundary line ks between the first side plate construction units H adjacent in the front-rear direction. The streaks 4a and 4b are arranged in the in-situ concrete placement space R1 (in-situ concrete placement space R2) before the side plate placing step s5.

  That is, a plurality of first side plate construction units H arranged in the front-rear direction are firmly integrated with the cast-in-place concrete. In the same way, the second side plate construction unit J is also connected to the external distribution bar and is firmly integrated by placing the cast-in-place concrete.

  As shown in FIGS. 10, 11, and 21, the steps for forming the top plate D are as follows. The top plate constituting block is formed on the inner side plate forming member 6 in the second side plate construction unit J. A top plate placing step s7 is performed after the top plate constituting block installation step s6 for installing L and the top plate constituting block installing step s6, and the on-site cast concrete is placed in the on-site concrete placement space SD for the top plate. And.

  In the top plate constituent block installation step s6, a plurality of top plate constituent blocks L arranged in the front-rear direction are firmly connected by connecting means (not shown). Prior to the top plate placing step s7, the on-site concrete placement space SD for the top plate includes a reinforcing bar f7 erected on the horizontal portion L2 and the outer side of the second side plate construction unit J. A reinforcing bar f4 protruding from the plate forming member 5 and other reinforcing bars (not shown) are disposed.

  As described above, the method for constructing the box culvert A according to the present embodiment includes the bottom plate B, the left and right side plates C erected on both ends of the bottom plate, and the upper end portions of the left and right side plates C. This is a method for constructing a box culvert A provided with a top plate D erected. And the left and right side plates C are the first and second side plate building units H and J and the first and second on-site strikes provided in the first and second side plate building units H and J. It comprises first and second on-site side plate components I and K formed by placing on-site concrete in the concrete placement spaces R1 and R2.

  The first and second side plate building units H and J are the first side plate forming members made of precast concrete, the outer side side plate forming members 1 and 5 and the second side plate made of precast concrete. The inner plate side side plate forming members 2 and 6 which are side plate forming members, and the outer plate side side plate forming members 1 and 5 and the inner plate side side plate forming members 2 and 6 are first, A plurality of rebars 4 and 7 as support members for supporting the inner side and outer side side plate forming members 1, 5, 2, and 6, respectively, in the state where the second cast-in-place concrete placement spaces R 1 and R 2 are formed. It is equipped with.

  The steps for forming the side plate C include first and second side plate building unit installation steps s3 and s4 for installing the first and second side plate building units H and J at predetermined positions, After the second side plate construction unit installation steps s3 and s4, the cast-in-place concrete is cast in the first and second concrete placement spaces R1 and R2 in the first and second side plate construction units H and J. And a side plate placing step s5.

  For this reason, the construction method of the box culvert A which can construct | assemble the comparatively large-sized box culvert A suitably can be provided by using a cast-in-place concrete together with the member made from a precast concrete.

  That is, the first and second side plate building units H and J include the outer side side plate forming members 1 and 5, the inner side side plate forming members 2 and 6, and the plurality of reinforcing bars 3 and 7. It is unitized so that it can be handled integrally. In order to build the side plate C of the box culvert A, the first and second side plate building units H and J, which are unitized building members, are used. The construction member can be managed in units. Therefore, according to the construction method of the box culvert A of the present embodiment, the large box culvert A using the precast concrete member can be constructed with high accuracy and smoothly.

  Further, by applying the method for constructing the box culvert A in this embodiment, the generation of subdivided members is suppressed, and the half precast box culvert A can be constructed without difficulty. As a result, it is possible to reduce the size of the vehicle for carrying the members and the carry-in heavy machinery, shorten the construction period by improving the efficiency of the field work, and reduce the reinforcing bars and the formwork.

  By applying the construction method of the box culvert A shown in the present embodiment, a problem of shortage of work in the field recently, for example, special workers (work of formwork, reinforcing bars, scaffolding, temporary support work in the field) It is possible to cope with the problem of shortage of employees etc. within a limited number of people. In other words, by using the unitized first and second side plate construction units H and J for the construction of the box culvert A, the amount of setting up the formwork, reinforcing bars, scaffolding, temporary support work, etc. is reduced. Therefore, it is possible to flexibly cope with labor shortage.

  The first and second side plate construction units H and J form first and second on-site concrete placement spaces R1 and R2 communicating in the vertical direction. For this reason, after setting the first and second side plate building units H and J at predetermined positions, by placing the cast-in-place concrete in the first and second cast-in-place concrete placement spaces R1 and R2. The desired side plate C can be constructed.

  The side plate forming members 1, 2, 5, and 6 on the outer air side and the inner air side are plate-shaped and substantially parallel to each other. For this reason, it is easy to perform installation work on site.

  The first and second side plate building units H and J set the lower end edges 1e, 2e, 5e, and 6e of the outer side and inner side side plate forming members 1, 2, 5, and 6 to the same horizontal position. It is a thing. For this reason, the first and second side plate building units H and J can stably stand on the ground, the corner block F, and the first side plate building unit H. And the installation process can be carried out smoothly.

  Since the supporting members for supporting the outer air side and inner air side side plate forming members 1, 2, 5, and 6 are constituted by a plurality of reinforcing bars 3 and 7, the first and second on-site strike sides It is excellent in ensuring the rigidity in the plate components I and K.

  The first and second side plate building units H and J can change the separation distance between the outer side and inner side side plate forming members 1, 2, 5, and 6. The empty side plate forming members 1, 2, 5, 6 are supported by a plurality of reinforcing bars 3, 7. Therefore, the first and second side plate building units H and J are respectively installed at appropriate positions by adjusting the distances 1, 2, 5, and 6 of the outer side and inner side side plate forming members. Will be able to.

  The side plate building unit installation step, that is, the first and second side plate building unit installation steps s3 and s4 include a step of arranging a plurality of first and second side plate building units H and J adjacent in the front-rear direction. . Then, the externally arranged reinforcing bars 4a and 4b, which are reinforcing bars that can pass through the virtual boundary line ks between the first and second side plate building units H and J adjacent in the front-rear direction, are used as the on-site cast concrete arrangement spaces R1 and R2. It is arranged. For this reason, the first and second side plate construction units H, which are adjacent to the external force distribution bars 4a and 4b in the front-rear direction by interposing the cast-in-place concrete put into the cast-in-place concrete placement spaces R1 and R2, Connection with J can be ensured appropriately.

  The present invention is not limited to the embodiment described in detail above.

  The construction method of the bottom plate and the top plate constituting the box culvert may be an application of an appropriate construction method. That is, most of the bottom plate and the top plate may be formed by in-situ concrete, or most of the bottom plate and the top plate may be formed by a precast concrete block.

  The step for forming the side plate may be applied to form only a part of the side plate. That is, the side plate construction unit installation step and the side plate placing step may be applied to only a part of the side plate.

  The side plate construction unit can adopt various forms as long as it has a unitized form, and is not limited to the one shown in the above-described embodiment.

  For example, the first and second side plate forming members constituting the side plate building unit are not limited to plate-like members, and those having various shapes can be adopted.

  Further, the support member constituting the side plate building unit is the first side plate forming member in a state in which an in-situ concrete placement space is formed between the first side plate forming member and the second side plate forming member. As long as it supports the second side plate forming member and the second side plate forming member, any member may be used.

  For example, as shown in FIGS. 17 and 18, the support member may include iron plates 3 ′ and 7 ′ in addition to the reinforcing bars 3 and 7.

  The support member may be a member to which a shape steel such as an H-shaped steel, an I-shaped steel, an L-shaped steel, a T-shaped steel, a flat steel, or a grooved steel is applied.

  The support member may be made of a material other than metal, for example, a material made of wood or synthetic resin.

  Needless to say, the support member functions as a reinforcing material for the in-situ side plate component after the in-situ concrete is placed.

  The support member applied to the side plate construction unit is not limited to one constituted by one type of steel material, and may be one in which a plurality of types of steel materials are applied. For example, the support member may be configured by using an appropriate number of both iron plates and reinforcing bars.

  In the above-described embodiment, the support member is applied with a plurality of reinforcing bars, but may be a single reinforcing bar or a plurality of reinforcing bars set to a smaller number than the above-described embodiment. It may be configured.

  In the embodiment described above, one end side of the plurality of reinforcing bars as the support member is configured to be movable with respect to the side plate forming member. However, the present invention is not limited to this.

  For example, as shown in FIGS. 17 and 18, the support member 3 may be attached to the side plate forming members 1, 2, 5, and 6 on both sides so as not to move. Further, the thickness of the reinforcing bar 12 provided on the outer side side plate forming member 1 may be configured to be thicker than the reinforcing bar 22 provided on the inner side side plate forming member 2.

  In the above-described embodiment, two types of side version building units are used for building the side version. However, the present invention is not limited to this. In building the side version, one type of side version building unit may be used, or two or more types of side version building units may be used. It goes without saying that one side plate building unit may be stacked in the vertical direction to build the side plate.

  The side plate construction unit may be provided with a reinforcing steel material that cantileverly protrudes from the side plate forming member to the in-situ concrete placement space together with the support member.

  For example, as shown in FIGS. 13 to 15, the side plate construction unit H is made of cast-in-place concrete from both the outer air side and the inner air side side plate forming members 1 and 2 together with a support member (not shown). It is assumed that the reinforcing steel material f1 protruding in a cantilever manner is provided in the arrangement space R1. The reinforcing steel material f1 has one end embedded in the side plate forming members 1 and 2 on the outer air side and the inner air side. The reinforcing steel material f1 can exhibit a reinforcing function with respect to the on-site strike side plate component after the on-site cast concrete is placed. Note that the reinforcing steel materials f1 protruding from both the outer air side and the inner air side side plate forming members 1 and 2 are arranged so as to overlap each other when viewed from a predetermined direction orthogonal to the longitudinal direction. It is desirable.

  In order to increase the degree of connection between the side plate building units adjacent in the front-rear direction, external strength bars, which are reinforcing bars that can pass through the virtual boundary line between the side plate building units adjacent in the front-rear direction, are placed on-site. It is desirable to arrange in a space.

  That is, what is shown in FIG. 16 has a shape in which the front edge and the rear edge of the side plate forming member 1 constituting the side plate building unit H are cut out in plan view. Then, in the cutout space RK created by the cutout, the external force distribution bars 4a serving as reinforcing bars are arranged so as to pass through the virtual boundary line ks between the side plate construction units H. The external force distribution bars 4a in this embodiment are attached to one side of the adjacent side plate construction unit H. By configuring in this manner, the cast-in-place concrete is disposed in the cast-in-place concrete placement space R1 including the notch space RK, and after the cast-in-place concrete is cured, the side plate building units H adjacent in the front-rear direction are arranged. The firm connection is ensured.

  As shown in FIG. 16, the side plate building unit H having the side plate forming member 1 with the front and rear end edges cut away is hung at a predetermined position so that another side plate building unit adjacent to the side plate building unit H is suspended. It is possible to install without interfering with H.

  Various arrangement modes of the plurality of side plate construction units adjacent in the front-rear direction can be set, and are not limited to those shown in the above-described embodiments.

  For example, the thing as shown in FIG.19 and FIG.20 can be considered. That is, in this embodiment, the embedded form U is interposed between a pair of side plate construction units H adjacent in the front-rear direction. In other words, in the step for forming the side plate, the side plate building unit H is disposed with a predetermined gap sk in the front-rear direction, and the embedded formwork U is disposed between the side plate building units H. It has a process. The embedded formwork U is disposed between the first formwork panel u1 disposed between the adjacent outer side side plate forming members 1 and the second inner side side plate forming member 2 disposed adjacent to each other. A formwork panel u2 and a support frame u3 that supports the first and second formwork panels u1 and u2 are provided. The first and second formwork panels u1 and u2 are formed in a plate shape by, for example, high-strength fiber reinforced mortar.

  In this embodiment, the plurality of side plate building units H are installed with a gap sk of about 10 cm in the front-rear direction. Concave portions 15 and 25 are formed at the front and rear end edges on the outer surface side of each side plate forming member 1 and 2. The embedded form U is installed suspended from above so as to engage with the recessed portions 15 and 25, for example. The first mold panel u1 is disposed between the pair of recessed portions 15 in the outer side side plate forming member 1 adjacent to the front and rear, and the second mold panel u2 is adjacent to the front and rear. It is arranged between the pair of recessed portions 25 in the side plate forming member 2 on the inner side.

  The support frame u3 that supports the first and second formwork panels u1 and u2 is supported so as to be movable with respect to one, ie, the second formwork panel u2. For this reason, after temporarily placing the embedded formwork U at a predetermined position, the second formwork panel u2 is tightly attached to the recessed portion 25 of the inner side plate forming member 2 by tightening the nut nt. It can arrange | position, adjusting appropriately to a position.

  In this embodiment, by burying the embedded formwork U between the side plate building units H arranged in the front-rear direction, it is possible to suitably absorb dimensional errors and installation position errors in the side plate building unit H. It has become.

  Between the outer air side and inner air side side plate forming members 1 and 2 in the side plate building unit H, a reinforcing bar 3 and an iron plate 3 ′ as support members are interposed.

  On the inner surface side of the side plate forming members 1 and 2 on the outer air side and the inner air side, support means sh (hook protruding in an L shape) capable of supporting the external force distribution bars 4a and 4b from at least the lower side, respectively. Is provided. External force distribution bars 4a and 4b can be placed on the support means sh. If such a support means sh is used, a temporary fixing operation by an operator is not necessary, so that comparison is made at a predetermined position along the outer air side and inner air side side plate forming members 1 and 2. It is possible to set the external force distribution muscles 4a and 4b with ease. For example, if the external force distribution muscles 4a and 4b are inserted from the wife side (small edge side), that is, the front side or the back side, and the external force distribution muscles 4a and 4b are installed at predetermined positions on the support means sh, the first It is possible to arrange the external force distribution bars 4a and 4b at predetermined positions without the need for an operator to enter the on-site concrete placement space R1. The external force distribution bars 4a and 4b, which are reinforcing bars, can pass through the virtual boundary line ks between the side plate construction units H adjacent in the front-rear direction, and are disposed in the on-site concrete placement space R1. is there. When the cast-in-place concrete is poured into the cast-in-place concrete placement space R1 and then hardened, the cast-in-place side plate component I is formed.

  For example, depending on the dimension in the height direction of the box culvert to be constructed, the first side plate construction unit and the second side plate construction unit may be integrated in advance to form a single side plate construction unit. Further, for example, by providing a third side plate building unit between the first side plate building unit and the second side plate building unit in the vertical direction, the side plate building unit constituting the side plate is provided. You may divide and comprise. In other words, the side plate construction unit applied to the side plate construction method may be two or more stacked in the vertical direction.

  Moreover, when the dimension of the width direction (cross direction) in the box culvert to construct is long, it can also be set as the structure which provided the wall or the column between the bottom plate and the top plate.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

A ... Box culvert B ... Bottom plate C ... Left and right side plates D ... Top plate H ... First side plate building unit (side plate building unit)
1 ... Outer side side plate forming member (first side plate forming member)
2 ... Inner side side plate forming member (second side plate forming member)
3 ... Several reinforcing bars (support members)
s3 ... Side plate construction unit installation process (first side plate construction unit installation process)
s5 ... Side plate placement process

Claims (9)

A method for constructing a box culvert comprising a bottom plate, left and right side plates standing upright at both ends of the bottom plate, and a top plate constructed between upper ends of the left and right side plates,
Each of the left and right side plates includes a side plate building unit, and a on-site side plate forming part formed by placing on-site cast concrete in a on-site cast concrete installation space provided on the side plate building unit. And
The side plate building unit includes a first side plate forming member made of precast concrete, a second side plate forming member made of precast concrete, and these first side plate forming member and second side plate forming. A support member that supports each of the first side plate forming member and the second side plate forming member in a state in which the in-situ concrete placement space is formed between the members,
The steps for forming the side plate include a side plate building unit installation step for installing the side plate building unit at a predetermined position, and after the side plate building unit installation step, the concrete arrangement of the side plate building unit. A method for constructing a box culvert, comprising: a side plate placing step for placing cast-in-place concrete in an installation space. The side plate construction unit forms the spot cast concrete arrangement space communicating in the vertical direction,
The first side plate forming member has a plate shape and is located on the outer air side of the box culvert,
The method for constructing a box culvert according to claim 1, wherein the second side plate forming member has a plate shape and is located on the inner space side of the box culvert. The side plate construction unit installation step includes a step of arranging a plurality of the side plate construction units adjacent to each other in a direction in which the internal space of the box culvert communicates,
The method for constructing a box culvert according to claim 1 or 2, wherein a reinforcing bar that can pass through a virtual boundary line between the adjacent side plate construction units is disposed in the spot cast concrete placement space. The method for constructing a box culvert according to any one of claims 1 to 3, wherein the first side plate forming member and the second side plate forming member have a plate shape and are substantially parallel to each other. . The said side plate construction unit sets the lower end edge of said 1st side plate forming member and the lower end edge of said 2nd side plate forming member in the same horizontal position, The any one of Claim 1 thru | or 4 The construction method of the box culvert described in 1. Either or both said 1st, 2nd side plate forming members are provided with the reinforcing steel material which cantilever-projected in the said cast-in-place concrete arrangement space. The construction method of the box culvert described in 1. The method for constructing a box culvert according to any one of claims 1 to 5, wherein the support member is made of one or a plurality of steel materials. The side plate construction unit is supported by the support member so as to change a separation distance between the first side plate forming member and the second side plate forming member. The box culvert construction method according to any one of the above. A box culvert having a bottom plate, left and right side plates standing on both ends of the bottom plate, and a top plate constructed between upper ends of the left and right side plates,
The left and right side plates include a side plate building unit, and a site-placed side plate component formed by placing the site-cast concrete in the site-cast concrete placement space provided in the side plate-building unit. And
The side plate construction unit is made of precast concrete and has a first side plate forming member, a second side plate forming member made of precast concrete, and these first side plate forming member and second side plate forming unit. A box culvert provided with a supporting member for supporting the first side plate forming member and the second side plate forming member in a state where the spot cast concrete arrangement space is formed between the members.

Images