JP3720025B2 - How to build a large box culvert - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a construction method of a large box culvert capable of easily assembling a large culvert. In particular, the present invention relates to a construction method of a large box culvert constructed by a side wall member and a top plate member having a novel structure made of precast concrete.
[0002]
[Prior art]
Traditionally, large culverts have been built on site by reinforced concrete. Therefore, the work such as the formwork at the site is complicated, and there is a problem in workability. In order to solve this problem, the present applicant has proposed a number of simple methods for assembling and constructing stacked blocks having a reduced size (Patent Document 1).
In addition, a side wall member in which the inner wall and the outer wall are planted with a space formed between the legs forming the bottom wall is formed by precast concrete with a predetermined width in the left and right pairs, and the inner wall of the side wall member is It is known that concrete is placed between an outer wall and a top plate member is stretched between inner wall upper ends of the left and right side wall members to construct a frame. (Patent Document 2). Furthermore, it is divided into a top wall part, both side wall parts, and a bottom wall part, and both side wall parts and the top wall part are molded with precast and concrete, transported to the site and assembled, and concrete is applied to the bottom wall part by placing reinforcing bars. A construction method for casting is also proposed (Patent Document 3).
[0003]
Patent Document 1 Japanese Patent Laid-Open No. 11-229212 Patent Document 2 Japanese Patent No. 3180316 Patent Document 3 Japanese Patent Laid-Open No. 2001-303654
The method of Patent Document 1 has no problem with a box culver that is not too large. However, when the size is large, there is a problem in the alignment and size adjustment of the reinforcing bars inserted into the block. The waterproofing process was very expensive. In addition, Patent Document 2 provides a space between the inner wall and the outer wall having different heights of the side wall member, and places the top plate member between the upper ends of the inner wall, and fixes and stretches the fixed plate member. Concrete is filled between the inner wall and the outer wall, and the purpose is to make the precast concrete lightweight. However, the hollow part between the inner wall and the outer wall of the side wall member may be damaged during transportation. There was a problem. Further, Patent Document 3 is composed of a top wall portion having a flat surface and both side wall portions, and a joint portion with the top wall portion placed on the upper end of both side wall portions is formed in a mountain shape, and a convex insert joint However, this portion is bonded with a resin adhesive or mortar and has low strength.
In the case of these Patent Documents 2 and 3, due to the difference in the design conditions at the construction site (1m, 2m, 3m of earth covering), the side wall member and the top plate member having different sizes are molded in the precast product manufacturing factory, Need to be prepared. The cost was high. In addition, since the earth pressure varies greatly depending on the difference in the covering, it is necessary to use side wall members and top plate members having different thicknesses.
[0005]
[Problems to be solved by the invention]
The present invention provides an improvement in the complexity of construction and the drawbacks of accuracy of the conventional large box culvert construction method as well as a good durability even in water.
An object of the present invention is to provide a culvert with a shortened construction and excellent strength in the field.
An object of the present invention is to provide a method for constructing a large box culvert that does not require complete waterproofing after construction and has little error in product accuracy after construction.
Another problem of the present invention is that it is manufactured in a factory with good quality control, can be easily transported to the construction site, can be easily assembled and integrated at the site, and uses standardized side wall members and top plate members. Another object of the present invention is to provide a construction method for a large box culvert that can be constructed in various sizes by changing the size of the reinforcing rib at the construction site.
[0006]
[Means for Solving the Problems]
The said subject of this invention can be achieved by the following structures.
A pair of concave cross-sectional side wall members and U-shaped top plate members, each having a U-shaped protruding leg, are made of precast concrete. A plurality of side wall members planted on both sides are arranged adjacent to each other via tension joints to form a wall portion, and a recess is formed between the upper ends of the side wall members. The top plate member is placed and stretched on the outside, and the connecting portion between the side wall member and the top plate member is positioned by a guide pin and connected by a tension joint, and the top plate member and the side wall member are large-sized. This is a construction method of a large box culvert in which a box frame is formed, a reinforcing bar is assembled and stretched with a predetermined width on the surface of the foundation bottom between the side wall members, and concrete having a predetermined thickness is placed.
[0007]
Another object of the present invention is to incorporate a PC steel rod into a concave flange on both sides of a concave shape of a pair of concave side wall members having a U-shaped leg projecting and a top plate member having a concave cross section. It is made of precast concrete, and the U-shaped overhangs of the legs of the pair of side wall members are placed inside to face each other on the foundation bottom at a predetermined interval. A wall portion is formed by arranging a plurality of adjacent ones via joints, and the top plate member is placed and stretched with the concave portion outside between the upper ends of the side wall members. The connecting part is positioned with a guide pin and connected with a tension joint, and a large box frame is formed by a top plate member and a side wall member provided with a PC steel rod in the collar part, and on the surface of the foundation bottom plate between the side wall members. Assemble and reinforce reinforcing bars with a predetermined width, and cast concrete with a predetermined thickness Can be achieved by a method for constructing a large box culvert was.
[0008]
An object of the present invention is to form a large box by the side wall member and the top plate member, and to reinforce a reinforcing bar on the surface of the base bottom plate between the side wall members, and to place a reinforcing bar in the concave portion of the side wall member and the top plate member. Weaving and embedding, concealing the concave portion of this side wall member with an outer plate, opening both ends of the top plate member and providing a plurality of openings at a constant interval at the central portion, and fixing with the outer plate. This can be achieved by a method for constructing a large box culvert in which concrete is cast from the opening of the member and concrete having a predetermined thickness is also cast on the reinforcing bar portion of the surface of the foundation bottom between the side wall members.
[0009]
Furthermore, the problem of the present invention is that the length of the reinforcing bars incorporated in the recesses after the construction without changing the length and width of the side wall member and the top plate member, and the length and width of the outer plate of the reinforcing rib The structure that can accommodate several types of soil covering lengths, and the central recess at the lower end of the side wall member is formed shorter than the side flanges, thereby incorporating the reinforcing bars to be laid on the legs of the space part This can be achieved by connecting the reinforcing bars in the recesses such as the side wall members and forming the reinforcing ribs and the foundation bottom wall by placing concrete in the reinforcing bars.
[0010]
In the construction method of the large box culvert of the present invention, the side wall member and the top plate member made of precast concrete are formed in a concave section with a predetermined thickness, so that they can be transported without trouble when transporting from the factory to the construction site. can do. Moreover, since it is precast in the factory, the accuracy control of the buried position of the tension joint and the like can be sufficiently performed.
[0011]
Moreover, the construction method of the large box culvert of the present invention is excellent in the strength of the side wall member because the reinforcement for the base bottom wall of the bottom wall is knitted and laid in the space between the legs. Moreover, because the concrete is cast by embedding reinforcing bars in the recesses between the top plate member and the side wall member, the strength of the side wall member is reinforced, and the intrusion of moisture and the like into the interior is prevented by the ready-mixed concrete receiving frame and the outer plate. can do.
In addition, there is a difference of 1m, 2m, and 3m on the construction site using a standardized size without changing the length and width of the side wall member and top plate member. This can be dealt with by changing the length and width of the reinforcing ribs such as the outer plate and the ready-mixed concrete receiving plate, so that it is not necessary to prepare a large number of precast product formwork and the cost can be reduced.
[0012]
Furthermore, since the side wall member is planted on the foundation bottom plate on which concrete is cast, the flatness of the bottom plate can be maintained, and a large box culvert with strength can be constructed. Since the inclined surface is formed in the connecting portion and connected to the concave portion of the side wall member, the reinforcing bars to be incorporated in the concave portion are strongly bonded. In addition, the foundation bottom wall rebar is assembled between the leg portions of the side wall member, and the reinforcing bar circulates in the recesses between the side wall member and the top plate member, and the concrete is placed. Excellent strength.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a construction method for a large box culvert according to the present invention will be described in detail with reference to the drawings.
1 to 3 are schematic explanatory views showing the work process of the construction method of the large box culvert of the present invention. FIG. 4 to FIG. 6 are schematic explanatory views for explaining the work process of another embodiment of the construction method of the large box culvert of the present invention. 7 and 8 are explanatory views showing an embodiment of the snow shelter in an area where the amount of snowfall is large in winter. FIG. 9 is an explanatory view showing an embodiment when a PC bar is inserted into the side wall member and the top plate member used in the present invention.
[0014]
A construction method of a large box culvert according to the present invention will be described based on an embodiment shown in the drawings.
An in-situ bottom plate 1 in which a level adjusting embedded rail 2 for positioning the leg 3c of the side wall member 3 having a concave cross section is laid at the construction site is formed. The leg portions 3c of the left and right side wall members 3 are made to face each other, and the lower surfaces of the leg portions 3c are aligned to be planted on the embedded rails 2, 2, 2, 2 of the spot bottom plate 1. The site bottom plate 1 is not necessary in the case of a ground or the like where flatness is maintained. However, since the surface of the ground is usually uneven, the side wall member 3 is constructed after the site bottom plate 1 is constructed. Build up.
A plurality of side wall tension joints 7 projecting from the side surfaces of the side wall members 3,... Are embedded in the upper end portion and the lower end portion, for example, and a plurality of side wall members 3 are arranged by fitting the side wall tension joints 7. Closely form sidewalls.
[0015]
On the upper surfaces of the left and right side wall members 3, 3, the top plate member 5 having a concave cross section is mounted with the concave portion 5 a facing upward, and the top plate is placed on the guide pins 4, 4 protruding from the end surface of the side wall member 3. The end surface of the member 5 is fitted, and the flange portion 5b of the top plate member 5 and the flange portion 3b of the side wall member 3 are connected to each other by the tension joint 6 and the flange portions 5b of the top plate member 5 are connected by the top wall tension joint 7a. Assembly. A foundation bottom plate bottom wall 10 is formed by braiding a foundation bottom plate reinforcing bar 9 on the spot bottom plate 1 surrounded by the legs 3c of the side wall member 3 and placing concrete around it (see FIG. 3).
[0016]
Another embodiment shown in FIG. 4 will be described.
After the frame body assembly process of the side wall member 3 and the top plate member 5 in FIG. 1 is constructed in the same manner, the rebar 8 is assembled into the concave portion 3a of the side wall member 3 and the concave portion 5a of the top plate member 5 and assembled. In particular, reinforcing bars are assembled obliquely on the inclined surfaces of both ends of the top plate member 5 and assembled. Similarly, the foundation bottom slab reinforcing bar 9 is assembled in the portion surrounded by the leg 3c, and the outer plate is formed between the flanges 3b and 3b of the side wall member 3, that is, the recess 3a is covered with the ready-mixed concrete receiving frame 11. Is done. When the ready-mixed concrete charging frame 11 is used as a reinforcing rib, the durability is increased.
On the other hand, an intermediate plate 12 covering the assembled reinforcing bar 8 disposed in the recess 5a of the top plate member 5 is disposed at a predetermined interval, and an opening is provided and fixed. Concrete is poured from the opening portion of the top plate member 5 of the frame body formed in this way and placed. Further, concrete is also placed on the foundation bottom slab reinforcement 9 for construction.
[0017]
The large box culvert of the present invention constructed in this way can be constructed by assembling the standardized side wall member 3 and top plate member 5 of a certain size, Large box culverts of several sizes with different wall thicknesses can be constructed simply by changing the sizes of the ready-mixed concrete receiving frame 11 and the intermediate plate 12 which are reinforcing ribs depending on the length of the earth covering.
[0018]
FIG. 7 is a perspective view showing an embodiment of a box culvert constructed by inclining a top plate member for a snow shelter, and the top plate member 5 with a ready-mixed concrete receiving frame 11 interposed in an extension portion of the side wall member 3 on one side. The side wall member 3 is provided with daylighting windows 13 at appropriate intervals. is there. FIG. 8 is a schematic explanatory view showing an embodiment in which the top plate member 5 of the snow shelter is formed in an arch shape.
[0019]
FIG. 9 shows the side wall member 3 and the top plate member 5 used in the method for constructing the large box culvert of the present invention, in which a PC steel bar is inserted into the flange of the wall thickness of the concave portion and tensioned and precast. The side wall member 3 and the top plate member 5 are inserted through the PC steel rod 14 and are strained. Even if the reinforcing bar is not embedded in the concave portion 3a of the side wall member 3 formed as described above, a box culvert excellent in strength can be constructed.
[0020]
【The invention's effect】
The large box culvert construction method of the present invention uses precast concrete side wall members and top plate members made of precast concrete manufactured under strict quality control in the factory, so it is easily transported to the construction site. It can be easily assembled at a construction site and can be constructed in a short time. Labor saving of assembly work at the construction site is possible.
[0021]
Moreover, not only the braiding by the assembled reinforcing bars is simple, but also the ready-mixed concrete receiving receiving frame is fitted into the recesses of the side wall member and the top plate member after the reinforcing bars are assembled, so that the ready-mixed concrete can be easily placed. The box culvert constructed in this way is acutely desired to be strong, and there is no exposure of the boundary surface, so waterproofing is not necessary.
In addition, large-sized box culverts having various sizes and thicknesses can be constructed at low cost by using standardized side wall members and top plate members.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing an operation process for assembling a side wall member and a top plate member on a basic bottom plate of a large box culvert construction method of the present invention.
FIG. 2 is an explanatory view illustrating a state in which the side wall member and the top plate member of the present invention are assembled.
FIG. 3 is an explanatory view showing a state constructed by the construction method of a large box culvert of the present invention.
FIG. 4 is a schematic explanatory view showing a state in which an assembled reinforcing bar is incorporated in a recessed portion of the assembled side wall member and top plate member 5 in another embodiment of the construction method of the large box culvert of the present invention.
FIG. 5 is an explanatory view showing a state in which an assembling reinforcing bar is knitted into the frame shown in FIG.
6 is a schematic explanatory diagram of a completed drawing of the large box culvert shown in FIG. 4. FIG.
FIG. 7 is a schematic perspective view showing an embodiment of a snow shelter in an area with a large amount of snowfall in winter in the large box culvert of the present invention.
FIG. 8 is a schematic perspective view showing an embodiment of a large box culvert in which a top plate member is constructed in an arch shape.
FIG. 9 is an explanatory view showing an embodiment when a PC bar is inserted into a side wall member and a top plate member used in the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Foundation bottom plate 2 Embedded rail 3 Side wall member 4 Guide pin 5 Top plate member 6 Tension joint 7 Side wall tension joint 8 Assembly reinforcement 9 Foundation bottom wall reinforcement 10 On-site foundation bottom wall 11 Ready-mixed concrete receiving frame 12 Plate 13 Lighting window 14 PC steel bar

Claims (5)

The pair of concave side wall members and the top plate members having a concave cross section with leg portions protruding in a U-shape are made of precast concrete, and the U-shaped overhang portions of the leg portions of the pair of side wall members are inside. A plurality of side wall members planted on both sides are arranged adjacent to each other via tension joints to form a wall portion, and a recess is formed between the upper ends of the side wall members. The top plate member is placed and stretched on the outside, and the connecting portion between the side wall member and the top plate member is positioned by a guide pin and connected by a tension joint, and the top plate member and the side wall member are large-sized. A construction method of a large box culvert characterized by forming a box frame, assembling and reinforcing steel bars with a predetermined width on the surface of the foundation bottom plate between the side wall members, and placing concrete with a predetermined thickness. PC steel rods are built in pre-cast concrete by incorporating a pair of concave side wall members with leg portions protruding in a U-shape and a concave side wall member with a concave cross-section top plate member. A large number of side wall members planted on both sides are arranged adjacent to each other via tension joints, with the U-shaped protruding portions of the leg portions of the pair of side wall members facing each other on the foundation bottom plate at predetermined intervals. A wall portion is formed by arranging, and the top plate member is placed and stretched with the recessed portion between the upper ends of the side wall members, and the connecting portion between the side wall member and the top plate member is positioned by a guide pin. At the same time, they are connected by tension joints, and a large box frame is formed by a top plate member and a side wall member provided with a PC steel bar in the collar portion, and reinforcing bars are assembled and stretched with a predetermined width on the surface of the base bottom plate between the side wall members. It is a large, characterized by laying concrete with a predetermined thickness How to build a box culvert. After the large-sized box is formed by the side wall member and the top plate member, reinforcing bars are laid around the surface of the foundation bottom plate between the side wall members, and reinforcing reinforcing bars are knitted in the respective recesses of the side wall member and the top plate member. Embedding, concealing the side recesses of the side wall member with an outer plate, opening both ends of the top plate member and providing a plurality of openings at regular intervals at the center portion and fixing with the outer plate to form a reinforcing rib 3. Concrete according to claim 1 or 2, wherein concrete is cast from the opening of the top plate member and concrete of a predetermined thickness is also cast on the surface of the foundation bottom between the side wall members. Construction method of the large box culvert described. After the construction without changing the length and width of the side wall member and the top plate member, by changing the length of the reinforcing bars incorporated in these recesses, the length and width of the outer plate of the reinforcing rib, The construction method for a large box culvert according to any one of claims 1 to 3, wherein the construction method can cope with the length of the earth covering. The center concave portion at the lower end of the side wall member is formed to be shorter than both side flanges, and reinforcing bars laid on the leg portions of the space portion formed thereby are incorporated, and concrete is driven to form a bottom wall. The construction method of the large-sized box culvert according to claim 1.

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