JP7334948B2 - Culvert structure and its construction method - Google Patents

Description

The present invention relates to a culvert structure using precast concrete members and a construction method thereof.

In recent years, new construction of trunk roads has shifted from plain areas to mountainous areas, and new construction of roads passing through steep mountainous areas is increasing. In road construction in mountainous areas, as the ratio of tunnels and bridges increases, high embankments will increase, and the construction of culvert structures (simply called culverts) that crosses these will increase. As culvert structures, box culverts having a substantially rectangular frame-shaped cross section, arch culverts having a horseshoe-shaped cross section (arch-shaped cross section), and the like are known, and these structures are made of, for example, reinforced concrete. In general, a structure such as a tunnel is constructed by constructing an embankment in parallel with or after construction of a culvert structure.

As a technique for constructing a culvert structure, a technique of embedding reinforcing bars in concrete is generally known. Techniques are disclosed. Further, for example, Patent Literature 2 discloses a reinforcement arrangement technique for a reinforcing member for improving the proof stress of a planar member among reinforced concrete structural members.

Also, when constructing a culvert structure, so-called precast concrete members (also simply called precast members) are sometimes used, in which members manufactured in advance at a factory or the like are brought to the site and assembled to existing members. .

Utility Model Application Publication No. 54-6984 JP 2013-221355 A

In the reinforced concrete structure as described in Patent Documents 1 and 2, the reinforcing bars in the concrete are arranged by casting on site, which tends to complicate the work. In particular, the corners of culvert structures require more efficient on-site work due to the use of complicated reinforcement structures.

Therefore, the object of the present invention is to improve the work efficiency during construction by using precast concrete members, to ensure the transportability of the members, and to ensure the bearing strength of the constructed culvert structure. It is to provide a possible culvert structure and its construction method.

In order to achieve the above object, according to the present invention, there is provided a culvert structure made of reinforced concrete, comprising a side wall constituting a side surface of the culvert structure, a top slab constituting a ceiling surface of the culvert structure, wherein the top plate comprises a precast top plate member as a lower structure and a field cast top plate member as an upper structure, and the precast top plate members are arranged in parallel in the width direction of the culvert structure A lower main reinforcing bar, a plurality of lower distributing bars perpendicular to the lower main reinforcing bar and arranged parallel to the longitudinal direction of the culvert structure, and a plurality of lower distributing bars arranged parallel to the width direction of the culvert structure, the precast and a plurality of corrugated reinforcing bars having a corrugated shape in which peaks and valleys alternately rise and fall in the thickness direction of the top slab member, and the lower main reinforcing bar and the lower force distribution bar extend from the precast top. The corrugated reinforcing bar is provided inside the plate member, and the lower part in the height direction of the corrugated reinforcing bar is embedded in the precast concrete part of the precast top plate member, and the upper part in the height direction is the precast top plate. A culvert structure is provided which is configured to protrude into said cast-in-place top plate member from a precast concrete portion of the member.

The precast top plate member has thickened portions that are thickened downward at both ends in the width direction, the thickened portions constitute the corner portions of the culvert structure, and the wave height of the corrugated reinforcing bars is , the wave height may be amplified in the thickened portion so as to cover the inside of the thickened portion.

A plurality of upper main reinforcing bars arranged parallel to the width direction of the culvert structure and arranged perpendicular to the upper main reinforcing bars and arranged parallel to the longitudinal direction of the culvert structure inside the in-situ top slab member. A plurality of upper distributing bars may be provided, and the upper main reinforcing bars and the upper distributing bars may be provided at positions corresponding to upper ends of the corrugated reinforcing bars.

The upper main reinforcing bar is composed of a bent portion including bent portions at both ends of the top plate in the width direction, and a straight portion located substantially in the center of the width direction of the top plate, and is one of the reinforcing bars protruding to the upper part of the side wall. The portion and the bent portion may be connected via a rebar receiving hole.

The precast top plate member has thickened portions that are thickened downward at both ends in the width direction, and the reinforcing bars protruding to the upper part of the side walls are the first reinforcing bars along the outer surface side of the side walls and the side walls. A second reinforcing bar along the inner surface side, wherein the first reinforcing bar is connected to the bent portion through a reinforcing bar receiving hole inside the thickened portion, and the second reinforcing bar is inside the thickened portion , and the upper end thereof may be embedded in the cast-in-place plate member.

The reinforcing-bar receiving hole may be a sleeve-type reinforcing-bar joint structure in which reinforcing bars are connected by injecting a time-hardening material into the hole and hardening the material.

According to another aspect of the present invention, in the method for constructing a culvert structure described above, the reinforcing bars protruding to the upper part of the side wall are the first reinforcing bars along the outer surface side of the side wall and the side wall. A side wall construction step of constructing a side wall on the ground , which consists of a second reinforcing bar along the inner surface of the second reinforcing bar and has a plurality of reinforcing bars protruding upward, and a plurality of reinforcing bars protruding from the side wall are received in the reinforcing bar receiving hole. A precast top plate member installation step of installing the precast top plate member on the upper part of the side wall in a state of being folded, and the upper main reinforcing bar, the upper distributing bar, the upper end of the second reinforcing bar, and the corrugated reinforcing bar A method for constructing a culvert structure is provided, comprising: a step of constructing a cast-in-place top slab for constructing cast-in-place concrete so that a portion protruding from the precast concrete portion is embedded in the concrete.

According to the present invention, by using precast concrete members, it is possible to improve the work efficiency during construction, ensure the transportability of the members, and ensure the bearing strength of the constructed culvert structure. In addition to reinforcing the corners of the constructed culvert structure, by installing corrugated reinforcing bars that serve as shear reinforcing bars, the strength of the entire structure can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic explanatory drawing of the culvert structure which concerns on embodiment of this invention. It is a schematic explanatory drawing regarding the construction method of a culvert structure. It is a schematic explanatory drawing regarding the construction method of a culvert structure. It is a schematic explanatory drawing regarding the construction method of a culvert structure. It is a schematic explanatory drawing regarding the construction method of a culvert structure. It is a schematic explanatory drawing regarding the construction method of a culvert structure. It is a schematic explanatory drawing (substantially side view) which expanded the thickening part. It is a schematic explanatory drawing (substantially top view) which expanded the thickening part.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, constituent elements having substantially the same functional configuration may be denoted by the same reference numerals, thereby omitting redundant description. In addition, in this specification, the structure of the culvert structure 1 and its top plate (including the precast top plate member 20 described later) are shown in the drawings, and the ground on which the culvert structure 1 is installed, etc. It may be omitted for simplification of description and illustration. Also, in some cases, a reinforcing bar structure inside the member is illustrated for the sake of explanation.

(Configuration of culvert structure according to embodiment of the present invention)
FIG. 1 is a schematic explanatory diagram of a culvert structure 1 according to an embodiment of the present invention. The culvert structure 1 shown in FIG. 1 is a rectangular culvert-shaped hollow structure installed at the entrance of a tunnel or the like provided for a highway or railway (not shown). A route (not shown) is laid for the . Hereinafter, the direction in which the internal space of the culvert structure 1 extends is defined as the longitudinal direction, and the direction parallel to the laying surface of the culvert structure 1 and perpendicular to the longitudinal direction is defined as the width direction, and the culvert structure 1 is laid. The vertical direction of is defined as the height direction.

As shown in FIG. 1, the culvert structure 1 according to the present embodiment comprises side walls 5 (5a, 5b) constructed vertically with respect to the ground, and a top slab 10 that is a ceiling surface. The top slab 10 has a two-layer structure consisting of a precast top slab member 20 as a lower structure and an on-site top slab member 21 as an upper structure. A detailed configuration of the top plate 10 will be described later with reference to the drawings.

In addition, the precast top plate member 20 has a shape in which the thickness is increased downward at both ends in the width direction, and the increased thickness portions 25 (25a, 25b) constitute the upper corner portions of the culvert structure 1. . The shape of the thickened portion 25 can be arbitrarily designed. good. Here, the thickness of the thickened portion 25 is preferably about 40 to 50% of the thickness of the top plate 10 for the purpose of strengthening corner portions of the culvert structure 1 and preventing stress concentration.

(Construction method of culvert structure)
Here, a method for constructing the culvert structure 1 according to the present embodiment will be described. 2 to 6 are schematic explanatory diagrams relating to the construction method of the culvert structure 1, showing the construction process in the order of FIGS. It should be noted that the configurations of the reinforcing bars shown in FIGS. 2 to 6 are examples, and the arrangement and number of these bars can be designed arbitrarily.

As shown in FIG. 2, first, the left and right side walls 5 (5a, 5b) are constructed with, for example, cast-in-place concrete. At this time, reinforcing bars 30 are provided on the side walls 5, and a plurality of reinforcing bars 30 are provided on the upper ends of the side walls 5 so as to protrude upward (side wall construction step). The reinforcing bar 30 is composed of, for example, a first reinforcing bar 30a along the outer side of the side wall 5 and a second reinforcing bar 30b along the inner side of the side wall 5, each of which protrudes above the side wall 5 by a predetermined length. there is

Next, as shown in FIG. 3, the precast top plate member 20 is installed on the upper part of the side wall 5 (precast top plate member installation step). Here, the thickened portion 25 of the precast top plate member 20 is provided with a reinforcing bar receiving hole 35 such as a through hole or a sleeve joint hole at a predetermined position, and the reinforcing bar 30 projecting to the upper part of the side wall 5 is A precast top slab member 20 is installed to pass through the rebar receiving hole 35 .

In addition, in the reinforcing bar receiving holes 35, when all the predetermined reinforcing bars are received, a time-hardening material such as mortar or concrete is injected and hardened to connect the side wall 5 and the precast top plate member 20. be done. As an example, a sleeve type rebar joint structure may be used as the rebar receiving hole 35 .

As shown in FIG. 3, the precast top slab member 20 includes a plurality of lower main reinforcing bars 40 arranged in parallel with the width direction of the culvert structure 1 and a direction orthogonal to the lower main reinforcing bars 40 (that is, , longitudinal direction of the culvert structure 1). The precast top plate member 20 is provided with a corrugated reinforcing bar 50 having a corrugated shape that rises and falls in its thickness direction (the height direction of the culvert structure 1). The corrugated reinforcing bar 50 is configured by one continuous reinforcing bar in the width direction of the culvert structure 1, and a plurality of such corrugated reinforcing bars 50 are arranged in the longitudinal direction of the culvert structure 1. be provided. Further, the upper side in the height direction of this corrugated reinforcing bar 50 is provided so as to protrude upward from the main body portion 20a (precast concrete portion) of the precast top plate member 20 made of precast concrete or the like. is buried in the body portion 20a.

Although the amount of protrusion of the corrugated reinforcing bars 50 from the main body 20a can be arbitrarily designed, as shown in FIG. In order to obtain the effect of anti-slipping between the precast top slab member 20 and the site-cast top slab member 21, the protruding amount of the corrugated reinforcing bars 50 is preferably five times or more the diameter of the reinforcing bars. On the other hand, an increase in the amount of reinforcing steel leads to an increase in the weight of the precast top plate member 20, and there is a concern that work efficiency and transportability during construction will decrease. In addition, the upper limit of the amount of projection of the corrugated reinforcing bars 50 ensures a reinforcing bar covering that is not affected by corrosion when the corrugated reinforcing bars 50 are embedded in cast-in-place concrete (the top plate member 21 described later). It is preferable to make it as high as possible.

Then, as shown in FIGS. 4 and 5 , a plurality of upper main reinforcing bars 60 arranged parallel to the width direction of the culvert structure 1 are provided at the upper end portions (peak portions) of the corrugated reinforcing bars 50 . Further, at the upper end of the corrugated reinforcing bars 50, a plurality of upper distributing bars 62 are provided in a direction perpendicular to the upper main reinforcing bars 60 (that is, the longitudinal direction of the culvert structure 1) (upper reinforcing bar arranging step). Here, as shown in FIG. 5, the upper main reinforcing bar 60 is composed of a bent portion 60a including bent portions at both ends in the width direction, and a straight portion 60b positioned substantially in the center in the width direction. For example, one end of the bent portion 60a is connected to the first reinforcing bar 30a and the other end is connected to the straight portion 60b. For this connection, for example, a sleeve type reinforcing bar joint structure is used.

Then, as shown in FIG. 6, the projecting portion of the upper main reinforcing bar 60, the upper distributing bar 62, the protruding portion of the corrugated reinforcing bar 50 from the main body portion 20a, and the upper end of the second reinforcing bar 30b are buried in the concrete. Concrete is poured to construct the on-site top slab member 21 (on-site top slab construction process). As described above, the side wall 5, the precast top slab member 20, and the on-site top slab member 21 are integrated with the inner reinforcing bars connected to each other, and the culvert structure 1 according to the present embodiment is constructed.

(Configuration of reinforcing bars in precast top plate member)
The culvert structure 1 according to the present embodiment is constructed as described above with reference to FIGS. is laid out. By means of these reinforcing bars, the connection between the side wall 5 and the precast top plate member 20 or the connection between the precast top plate member 20 and the on-site casting top plate member 21 is effectively realized, and the strength of the culvert structure 1 is improved. . Here, the configuration of the reinforcing bars in the thickened portion 25 will be described.

7 and 8 are schematic explanatory views enlarging the thickened portion 25 of the precast top plate member 20 and its vicinity in the culvert structure 1 according to the present embodiment, FIG. 7 being a schematic side view, and FIG. It is a top view. As shown in FIGS. 7 and 8, the precast top plate member 20 is provided with a plurality of lower main reinforcing bars 40, a plurality of lower force distribution bars 42, and corrugated reinforcing bars 50 protruding upward. Further, as shown in the figure, a through hole or a sleeve joint hole as a reinforcing bar receiving hole 35 is provided inside the thickened portion 25, and the reinforcing bar 30 provided in the side wall 5 and the upper main reinforcing bar 60 are inserted into the reinforcing bar receiving hole 35. 35.

The upper side of the corrugated reinforcing bars 50 is embedded in the on-site top plate member 21, and a plurality of upper main reinforcing bars 60 and a plurality of upper distributing bars 62 are provided. and a reinforcing bar 30 (first reinforcing bar 30 a ) are connected through a reinforcing bar receiving hole 35 . On the other hand, in the thickened portion 25, the lower side of the corrugated reinforcing bar 50 has a corrugated shape extending into the thickened portion 25, and the wave height of the corrugated reinforcing bar 50 provided in the precast top plate member 20 is , the structure differs depending on the position in the member (body portion 20a and thickened portion 25). The wave height of the corrugated reinforcing bars 50 is arbitrarily designed, and in the thickened portion 25, the wave height is amplified to cover the inside thereof. That is, the corrugated reinforcing bars 50 protrude above the precast top plate member 20 and are arranged so as to cover the entire interior of the precast top plate member 20 .

Also, the upper main reinforcing bar 60 and the upper distributing bar 62 may be arranged at a position corresponding to the upper end of the corrugated reinforcing bar 50 , and the upper distributing bar 62 is the upper end (peak) of the corrugated reinforcing bar 50 . , and as shown in the figure, the upper distributing bar 62 may be provided so as to communicate near the inside of the upper ends of the plurality of corrugated reinforcing bars 50 .

Further, the culvert structure 1 is provided with oblique reinforcing bars 70 over the inside of the precast top plate member 20 and the in-situ top plate member 21 . As shown, the diagonal reinforcing bars 70 are disposed primarily within the thickened portion 25 and the cast-in-place top slab 21, one end of which is fixed to the upper distributing bar 62 and the other end of which is fixed to the upper distributing bar 62. It is fixed to auxiliary reinforcing bars 72 arranged in the thickened portion 25 . The oblique reinforcing bars 70 are basically provided along the inner surface side of the thickened portion 25 (the inner surface side of the culvert structure), and the ends thereof fit inside the thickened portion 25 according to the shape of the thickened portion 25. It can be folded like this.

(Effect)
According to the culvert structure 1 configured as described above with reference to FIGS. Among the reinforcing bars provided inside, the upper side in the height direction of the corrugated reinforcing bars 50 is configured to protrude upward from the main body 20a made of precast concrete or the like. This corrugated reinforcing bar 50 plays a role as a corner reinforcing reinforcing bar of the culvert structure 1, and also plays a role of slip prevention between the precast top plate member 20 and the on-site top plate member 21 (joint position). As a result, the structural safety and strength of the constructed culvert structure 1 are sufficiently ensured. In addition, the corrugated reinforcing bar 50 uses a single reinforcing bar formed into a corrugated shape. It is possible to improve the yield strength of

Further, in constructing the culvert structure 1, the side wall 5 and the cast-in-place top plate member 21 are cast-in-place members, while the precast top plate member 20 is a so-called precast concrete member that is manufactured in advance at a factory or the like. As a result, when the culvert structure 1 is made of reinforced concrete, instead of building the culvert structure 1 entirely with precast members, by using precast members for the parts that require the most time and effort in the cast-in-place construction method, the material cost can be reduced. reduction and shortening of the construction period will be realized. By adopting such a so-called half precast structure, precast members are used for members that have the most complicated bar arrangement structure and are difficult to cast in place, and other members are cast in place. It is possible to achieve both improvement in work efficiency and transportability of members.

In particular, corners (corresponding to thickened portions 25 in the present embodiment) of the culvert structure 1 are intricately arranged with rebars for corner reinforcement as countermeasures against earthquakes and the like. known and can be difficult to install using cast-in-place methods. Therefore, as the precast top slab member 20 according to the present embodiment, a member having such a complicated reinforcing bar arrangement structure is manufactured in advance at a factory or the like, and transported to the site. Reduction and shortening of construction period are planned.

Further, in the present embodiment, the precast top slab member 20 is configured such that the oblique reinforcing bars 70 are housed inside the thickened portion 25 . As a result, the reinforcing bar arrangement structure in the thickened portion (so-called haunch portion) 25 of the precast top plate member 20 can be easily manufactured in a factory in advance.

Further, in the precast top plate member 20 according to the present embodiment, the reinforcing bar receiving holes 35 such as through holes or sleeve joint holes are provided in the thickened portion 25 . Then, in a state in which a predetermined reinforcing bar is received in the reinforcing bar receiving hole 35, a time hardening material such as mortar or concrete is injected and hardened to perform connection. By firmly connecting each member such as the side wall 5, the precast top plate member 20, and the site-cast top plate member 21 using such connecting means, the culvert structure 1 with high safety can be constructed efficiently. can.

Although an example of the embodiment of the present invention has been described above, the present invention is not limited to the illustrated form. It is obvious that a person skilled in the art can conceive various modifications or modifications within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. understood as a thing.

For example, in the above embodiment, the side wall 5 is constructed by the cast-in-place method, but the side wall 5 may also be a precast member. In addition, although it has been explained that the plurality of upper main reinforcing bars 60 and the plurality of upper distributing bars 62 are arranged at the time of construction at the site, these upper main reinforcing bars 60 and the upper distributing bars 62 are also precast top slab members 20 may be prefabricated at the factory as part of the In particular, when the culvert structure 1 is small, it is preferable to use precast members as much as possible in consideration of the transportability of the members.

In addition, in the above-described embodiment, the illustrated and described reinforcing bar structure is an example, and various reinforcing bars (lower main reinforcing bars, lower distributing bars, corrugated reinforcing bars, upper main reinforcing bars, upper distributing bars, oblique reinforcing bars, auxiliary reinforcing bars, etc.) ) can be designed arbitrarily.

INDUSTRIAL APPLICABILITY The present invention can be applied to a box culvert top plate member using precast concrete members, a culvert structure, and a construction method thereof.

DESCRIPTION OF SYMBOLS 1... Culvert structure 5... Side wall 10... Top plate 20... Precast top plate member 21... On-site top plate member 25... Thickening part 30... Reinforcing bar (of side wall) 35... Reinforcing bar receiving hole 40... Lower main reinforcing bar 42... Lower part Distributing bar 50 Corrugated reinforcing bar 60 Upper main reinforcing bar 62 Upper distributing bar 70 Oblique reinforcing bar 72 Auxiliary reinforcing bar

Claims (7)

A culvert structure made of reinforced concrete,
a side wall forming a side surface of the culvert structure;
A top plate that constitutes the ceiling surface of the culvert structure,
The top slab comprises a precast top slab member as a lower structure and a site-cast top slab member as an upper structure,
The precast top slab member includes a plurality of lower main reinforcing bars arranged parallel to the width direction of the culvert structure;
a plurality of lower distributing bars orthogonal to the lower main reinforcing bars and arranged parallel to the longitudinal direction of the culvert structure;
and a plurality of corrugated reinforcing bars arranged in parallel to the width direction of the culvert structure and having a corrugated shape in which peaks and valleys alternately rise and fall in the thickness direction of the precast top plate member. ,
The lower main reinforcing bars and the lower distributing bars are provided inside the precast top slab member,
A portion of the corrugated reinforcing bar on the lower side in the height direction is embedded in the precast concrete portion of the precast top plate member, and a portion on the upper side in the height direction extends from the precast concrete portion of the precast top plate member to the site. A culvert structure, characterized in that it is configured to protrude into the top plate member. The precast top plate member has thickened portions that are thickened downward at both ends in the width direction,
The thickened portion constitutes a corner portion of the culvert structure,
The culvert structure according to claim 1, wherein the wave height of the corrugated reinforcing bars is amplified in the thickened portion to a wave height that covers the inside of the thickened portion. a plurality of upper main reinforcing bars arranged parallel to the width direction of the culvert structure inside the top plate member;
a plurality of upper distributing bars orthogonal to the upper main reinforcing bars and arranged parallel to the longitudinal direction of the culvert structure;
The culvert structure according to claim 1 or 2, wherein the upper main reinforcing bars and the upper distributing bars are provided at positions corresponding to upper ends of the corrugated reinforcing bars. The upper main reinforcing bar is composed of a bent portion including bent portions at both ends of the top plate in the width direction, and a straight portion positioned substantially in the center of the width direction of the top plate,
4. The culvert structure according to claim 3, wherein a part of the reinforcing bar protruding to the upper part of the side wall and the bent portion are connected through a reinforcing bar receiving hole. The precast top plate member has thickened portions that are thickened downward at both ends in the width direction,
The rebar protruding to the upper part of the side wall consists of a first rebar along the outer side of the side wall and a second rebar along the inner side of the side wall,
The first reinforcing bar is connected to the bent portion through a reinforcing bar receiving hole inside the thickened portion,
5. The culvert structure according to claim 4, wherein said second reinforcing bar passes through a through hole inside said thickened portion, and its upper end is embedded in said cast-in-place top slab member. The culvert structure according to claim 4 or 5, wherein the reinforcing bar receiving hole is a sleeve-type reinforcing bar joint structure that connects the reinforcing bars by injecting a time-hardening material into the hole and hardening it. thing. A method for constructing a culvert structure according to any one of claims 4 to 6,
The rebar protruding to the upper part of the side wall consists of a first rebar along the outer side of the side wall and a second rebar along the inner side of the side wall,
A side wall building process of building a side wall with a plurality of reinforcing bars protruding upward on the ground;
a precast top plate member installing step of installing the precast top plate member on the upper part of the side wall in a state in which a plurality of reinforcing bars protruding from the side wall are received in the reinforcing bar receiving holes;
Cast-in-place concrete is applied so that the upper ends of the upper main reinforcing bars, the upper distributing bars, the upper ends of the second reinforcing bars, and the portions of the corrugated reinforcing bars protruding from the precast concrete portion are embedded in the concrete. and a top slab construction step.

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