JP7564041B2 - Method for forming furnace pit and composite slab - Google Patents

Description

The present invention relates to a method for forming a composite slab with a boiler pit space in buildings such as steel-reinforced concrete structures, and to a boiler pit used therein.

Patent Document 1 discloses a pump pit formwork that eliminates the need to remove the pump pit formwork or perform finishing processes after pouring concrete, shortening the construction period and preventing water leakage.

JP Patent Publication No. 7-26618

There is a technique to form a composite slab by forming a steel frame on top of a foundation slab, placing a deck plate on top of the steel beams, placing reinforcing bars on top of the deck plate, and pouring concrete on top of the deck plate using the deck plate as the bottom of the formwork. A space exists between the composite slab formed in this way and the foundation slab.
In order to provide a boiler pit in such a composite slab, a recess is conventionally provided on the bottom surface formed by the deck plate to surround the boiler pit, reinforcing bars are placed at the bottom of the recess, and concrete for the bottom of the boiler pit is poured. Then, rising reinforcing bars are placed on top of the bottom concrete, rising formwork is installed, and the concrete for the sides of the boiler pit is poured at the same time as the concrete for the main body of the composite slab. This requires pouring the concrete in two stages. The rising formwork in the recess is then removed. Thus, providing a boiler pit in a composite slab requires a lot of work, a long construction period, and high costs.
By applying the technology disclosed in Patent Document 1, it is not necessary to remove the formwork; however, the effort required for forming recesses and arranging reinforcement remains the same.
An object of the present invention is, for example, to solve such problems and to easily form a composite slab having a furnace pit.

The boiler pit has side panels and a bottom panel, and is equipped with a boiler pit defining part that defines a boiler pit space with an open top, legs that extend downward from the boiler pit defining part and support the boiler pit defining part, fixing parts that are provided at the lower ends of the legs and fix the legs to the top surface of the foundation slab, deck plate abutment parts that extend outward from the side panels and abut against a deck plate, and a lid receiving part that is provided at the upper end of the side panels and receives a lid that covers the top surface of the boiler pit space. The part of the side panels above the deck plate abutment parts, together with the deck plate, becomes a formwork for concrete to be poured on the deck plate.
In a method for forming a composite slab having a boiler pit space, the boiler pit is placed on a foundation slab and fixed in place. A deck plate is installed around the boiler pit. Concrete is poured onto the deck plate using the side panels of the boiler pit and the deck plate as formwork.

The portion of the side panel above the deck plate contact portion, together with the deck plate, serves as a formwork for the concrete to be poured onto the deck plate, eliminating the need to pour the concrete in two separate steps. In addition, there is no need to pour concrete around the portion of the side panel below the deck plate contact portion, eliminating the need to lay reinforcing bars. This reduces the amount of work required, shortens the construction period, and keeps costs down.

FIG. 1 is a perspective view showing an example of a boiler pit. FIG. 2 is a side cross-sectional view showing an example of a boiler pit. FIG. 2 is a side cross-sectional view showing an example of a composite slab.

As shown in FIG. 1, the boiler pit 10 has, for example, a boiler pit defining portion 12 that defines a boiler pit space 11 having a substantially rectangular parallelepiped shape, a support portion 13 that supports the boiler pit defining portion 12, a fixing portion 14 for fixing the support portion 13, and a lid receiving portion 15 provided on the boiler pit defining portion 12.

As shown in FIG. 2, the boiler pit defining portion 12 is, for example, a rectangular box shape with an open top, and has rectangular side panels 21-24 and a rectangular bottom panel 25. The boiler pit defining portion 12 is formed, for example, by bending and welding a steel plate.

The lid receiving portion 15 receives the lid 106 (see FIG. 3) that covers the upper surface of the boiler pit space 11. The lid receiving portion 15 is, for example, a thin, roughly rectangular parallelepiped shape with openings on the top and bottom, and has rectangular plate-shaped side portions 51-54 and a bottom portion 55 with a large opening 56 in the center.

The support section 13 has, for example, four legs 31 to 34, a deck plate abutment section 36 that connects the upper end portions of the legs 31 to 34, a center beam section 37 that connects the middle portions of the legs 31 to 34, and a lower beam section 38 that connects the lower end portions of the legs 31 to 34.

The legs 31 to 34 are, for example, angle steel, and extend vertically along the edges between the side panels 21 to 24 of the boiler pit defining portion 12, and further extend downward to support the boiler pit defining portion 12 at a predetermined height. The legs 31 to 34 are fixed to the boiler pit defining portion 12, for example, by welding.

The deck plate abutment portion 36 has, for example, four beam members 61-64. The beam members 61-64 are, for example, angle steels that extend substantially horizontally along the side panels 21-24 of the boiler pit defining portion 12, with their end portions connected to the upper end portions of the legs 31-34. The beam members 61-64 are fixed to the boiler pit defining portion 12 and the legs 31-34 by, for example, welding.

The central beam section 37 has, for example, four beam members 71-74. The beam members 71-74 are, for example, angle steel, and extend approximately horizontally along the edge between the side panels 21-24 and the bottom panel 25 of the boiler pit defining section 12, with their end portions connected to the middle portions of the legs 31-34. The beam members 71-74 are fixed to the boiler pit defining section 12 and the legs 31-34 by, for example, welding.

The lower beam portion 38 is, for example, a substantially rectangular ring-shaped member, and has four beam members 81-84. The beam members 81-84 are, for example, angle steel members that extend substantially horizontally, with their end portions connected to each other. The lower end portions of the legs 31-34 are connected to the inside of the corners between the beam members 81-84. The beam members 81-84 are fixed to each other and to the legs 31-34, for example, by welding.

The fixing portion 14 has, for example, eight fixing pieces 41 to 48. The fixing pieces 41 to 48 are, for example, short angle irons, and are fixed to the beam members 81 to 84 of the support portion 13, for example, by welding. The fixing pieces 41 to 48 have through holes for inserting, for example, anchor bolts 91 to 98.

Next, we will explain how to use the boiler pit 10.

As shown in FIG. 3, the boiler pit 10 is placed on a foundation slab 101 formed, for example, from cast-in-place concrete, and the boiler pit 10 is fixed to the foundation slab 101 using anchor bolts 91 to 98.

Next, deck plates 102, 103 are installed at a predetermined height from the foundation slab 101, surrounding the boiler pit 10. At this time, the deck plates 102, 103 are abutted against the deck plate abutment portion 36 of the boiler pit 10 to prevent gaps. For example, the ends of the deck plates 102, 103 are placed on the deck plate abutment portion 36, or, as shown in Figure 3, the ends of the deck plates 102, 103 are butted against the ends of the deck plate abutment portion 36.

Then, reinforcing bars 104 are placed above the deck plates 102 and 103.

Thereafter, the deck plates 102, 103 and the outer surfaces of the boiler pit defining portion 12 are used as formwork.
Concrete 105 is poured to form a composite slab 100 consisting of the deck plate and reinforced concrete.

Finally, a lid 106 such as a steel grating is placed on the lid receiving portion 15.

In this way, a composite slab 100 with a furnace pit space 11 is formed.

Since there is no need to pour concrete on the bottom or outside of the lower side of the boiler pit defining section 12, there is no need to create a recess in the surface formed by the deck plate, and there is also no need to place reinforcing bars in the recess. This reduces the amount of work, shortens the construction period, and keeps costs down.
In addition, since the boiler pit 10 has a lid receiving portion 15, the labor required for installing the lid receiving portion is reduced, the construction period is shortened, and costs are reduced.

The above-described embodiment is an example for facilitating understanding of the present invention. The present invention is not limited thereto, and includes various modifications, changes, additions, or deletions without departing from the scope defined by the appended claims. This can be easily understood by a person skilled in the art from the above description.

As described above, in the construction method for installing the boiler pit on the foundation of a building, a steel boiler pit is installed before pouring concrete. The steel boiler pit supports the slab formwork and also serves as the frame for the permanent grating cover. This allows for a significant reduction in the construction time and cost of a complex pit.
Concrete is poured after a steel (galvanized steel, etc.) boiler area is installed. The steel boiler area is integrated with the support base of the lower pit and the support material for the slab formwork. It also serves as the bottom frame material for the lid. This means that concrete only needs to be poured once, shortening the construction period. There is no need to backfill the area around the boiler area with soil. Concrete is not required on the slope. The frame for the lid can be constructed first. There is no need for complex reinforcing bars such as diagonal bars.

10 boiler pit, 11 boiler pit space, 12 boiler pit defining portion, 13 support portion, 14 fixing portion, 15 lid receiving portion, 21-24 side panels, 25 bottom panel, 31-34 legs, 36 deck plate abutment portion, 37 center beam portion, 38 lower beam portion, 41-48 fixing pieces, 51-54 side portions, 55 bottom portion, 56 opening, 61-64, 71-74, 81-84 beam members, 91-98 anchor bolts, 100 composite slab, 101 foundation slab, 102, 103 deck plate, 104 reinforcing bars, 105 concrete, 106 lid.

Claims (2)

A boiler room pit defining portion having a side plate and a bottom plate and defining a boiler room pit space with an open top;
A leg portion extending downward from the boiler pit defining portion and supporting the boiler pit defining portion;
A fixing portion provided at a lower end of the leg and fixing the leg to an upper surface of a foundation slab;
A deck plate abutment portion extending outward from the side panel and abutting against the deck plate;
A lid receiving portion provided at the upper end of the side panel and receiving a lid covering the upper surface of the boiler pit space;
Equipped with
The portion of the side panel above the deck plate abutment portion serves, together with the deck plate, as a formwork for concrete poured onto the deck plate.
Boiler pit. The boiler pit of claim 1 is placed on a foundation slab and fixed thereon,
A deck plate is installed around the boiler pit,
Using the side plate of the boiler pit and the deck plate as formwork, pour concrete onto the deck plate.
A method for forming a composite slab having a furnace pit space.

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