JP2021139146A - Equipment base and construction method of equipment base - Google Patents

Abstract

To provide a construction method of an equipment base allowing the equipment base to be easily constructed on an existing floor slab surface.SOLUTION: An equipment base 20 formed to be erected from an existing floor slab surface E is provided with: mold frame members 1, 10 adhered to the floor slab surface along the outer shape of the equipment base; steel bars placed in an area surrounded by the mold frame members; and an erected part 21 integrally formed in the area with the mold frame members as well as the steel bars and concrete C.SELECTED DRAWING: Figure 6

Description

The present invention relates to an equipment foundation for constructing an equipment foundation on an existing floor slab surface and a method for constructing the equipment foundation.

When equipment such as a water tank, water heater, cubicle, generator, refrigerator, boiler, and air conditioner is installed in a building, the equipment foundation is formed in a board shape on the floor slab surface formed of concrete. This equipment foundation is constructed, for example, by installing a formwork on a floor slab, arranging reinforcing bars, and then placing concrete in the formwork.

In facilities such as hospitals and factories where many equipments are installed, there are many places where equipment foundations are installed, and it takes man-hours to construct these equipment foundations. It is desirable to construct the equipment foundation integrally with the floor slab in order to counter the force generated by external forces such as seismic loads.

When the equipment foundation and the floor slab are integrated, the reinforcing bars are arranged in advance before the concrete of the floor slab is placed, and the concrete is placed to form the floor slab surface where the reinforcing bars are exposed. After that, a formwork for the equipment foundation is assembled on the floor slab surface, concrete is placed including the exposed reinforcing bars, and the equipment foundation rising from the floor slab surface is constructed.

According to the method of constructing such an equipment foundation, the reinforcing bars exposed on the floor slab surface are bent and temporarily placed on the floor slab surface from the floor slab concrete placement to the construction of the equipment foundation. Need to keep. During this time, the reinforcing bars hinder the loading and unloading of materials and equipment, and work efficiency is reduced. In addition, when arranging the reinforcement of the equipment foundation, it is necessary to bend back the once bent reinforcing bar, which requires a corresponding man-hour.

In connection with this, for example, a technique for constructing an equipment foundation described in Patent Document 1 is known. According to the technique described in Patent Document 1, a frame-shaped rising portion is formed in advance on the floor slab surface as an integral structure, and a disc-shaped rising portion is formed in a region surrounded by the frame-shaped rising portion via a cushioning material. The equipment foundation is fitted and the equipment foundation is fixed.

Japanese Unexamined Patent Publication No. 2003-328509

According to the technique described in Patent Document 1, it is necessary to form a rising portion in advance on the floor slab surface, and the rising portion formed in advance is a resource from the placement of the floor slab concrete to the construction of the equipment foundation. It may interfere with the loading and unloading of equipment.

An object of the present invention is to provide an equipment foundation and a method for constructing an equipment foundation that can easily construct an equipment foundation on an existing floor slab surface.

In order to achieve the above object, the present invention is a formwork foundation formed by standing up from an existing floor slab surface, and a formwork member bonded to the floor slab surface along the outer shape of the equipment foundation. It is characterized by including a reinforcing bar arranged in an area surrounded by the formwork member, and a rising portion formed in the area by integrating the formwork member and the reinforcing bar with concrete. It is a facility foundation.

According to the present invention, the formwork member is adhered to the floor slab surface, concrete is cast, and then the formwork member is integrated as it is as a part of the equipment foundation to construct the formwork foundation. Removal is not required and construction can be simplified.

Further, the present invention may be configured such that the adhesive area is set so that the adhesive strength of the formwork member opposes the force generated by the external force acting on the equipment fixed to the equipment foundation. ..

According to the present invention, the adhesive strength generated by the adhesive area for adhering the formwork member and the floor slab surface with an adhesive is set so that the formwork member does not peel off from the floor slab surface even when an external force is applied to the equipment. Therefore, sufficient strength of the equipment foundation can be secured.

Further, the present invention may be configured such that the adhesive strength in the adhesive area is set so as to oppose the overturning moment generated in the equipment by the external force.

According to the present invention, even if an overturning moment is generated in the equipment due to an external force, the adhesive strength is set so that the formwork member and the floor slab surface do not peel off, so that the strength of the equipment foundation can be sufficiently secured.

Further, in the present invention, the formwork member may be configured to be formed at a height required for the equipment foundation.

According to the present invention, after the concrete is cast on the formwork member, the height of the formwork member becomes the height of the equipment foundation as it is, and it is not necessary to cut for adjusting the height of the formwork member, so that the construction can be simplified. ..

Further, in the present invention, the formwork member may be configured to be formed of precast reinforced concrete.

According to the present invention, the formwork member and concrete can be more integrated by forming the formwork member using precast reinforced concrete.

In order to achieve the above object, the present invention is a method for constructing an equipment foundation formed by standing up from an existing floor slab surface, and a formwork member is adhered to the floor slab surface along the outer shape of the equipment foundation. The step of arranging the reinforcing bars in the area surrounded by the formwork members, and the step of placing concrete in the area to integrate the formwork members, the reinforcing bars, and the concrete. It is a method of constructing a facility foundation, which is characterized by having.

According to the present invention, when constructing the equipment foundation on the floor slab surface, the formwork member is adhered on the floor slab surface, concrete is cast, and then the formwork member is integrated as it is as a part of the equipment foundation. By doing so, it is not necessary to remove the formwork member, and the construction can be simplified.

Further, the present invention may be configured to include a step of roughening the area before placing the concrete.

According to the present invention, the adhesive strength can be increased by roughening the area where the formwork member and the floor slab surface are adhered to increase the unevenness.

According to the present invention, the equipment foundation can be easily constructed on the existing floor slab surface.

It is a figure which shows the structure of the formwork member for constructing the equipment foundation which concerns on embodiment of this invention. It is a figure which shows the structure of the formwork member used for a corner part. It is a figure which shows the process of arranging the formwork member. It is a figure which shows the formwork member arranged along the outer shape of the equipment foundation. It is a figure which shows the process of arranging a reinforcing bar in a formwork member. It is a figure which shows the process of placing concrete in a formwork member. It is a side view of the equipment foundation for examining the adhesive strength of a formwork member. It is a top view of the equipment foundation for examining the adhesive strength of a formwork member.

Hereinafter, embodiments of the equipment foundation and the method for constructing the equipment foundation according to the present invention will be described with reference to the drawings. The equipment foundation is formed in a board shape on a flat floor slab surface in a building.

As shown in FIGS. 1 and 2, the equipment foundation is constructed by the formwork members 1 and 10. The formwork member 1 is formed by using, for example, precast reinforced concrete (PCaRC). PCaRC is a preformed reinforced concrete member. As will be described later, the formwork member 1 is assembled in a frame shape on the floor slab surface and is used as a concrete formwork. The length of the formwork member 1 is formed according to the design dimensions of the equipment foundation.

The formwork member 1 is formed, for example, in an L cross-sectional shape. The formwork member 1 includes a bottom plate portion 2 along the horizontal direction and a side plate portion 4 formed by rising upward along the vertical direction from one side surface 3 side of the bottom plate portion 2. The bottom plate portion 2 and the side plate portion 4 are formed so as to have the same width, for example.

The bottom plate portion 2 is formed in a strip shape. The lower surface 2A of the bottom plate portion 2 is adhered to the floor slab surface with an adhesive as described later. As will be described later, the bottom plate portion 2 has an area (adhesive area) of the lower surface 2A set so that the adhesive strength opposes the force generated by the external force acting on the equipment fixed to the equipment foundation. Concrete is cast on the upper surface 2B side of the bottom plate portion 2 as described later.

The side plate portion 4 is formed so as to have a height required for the equipment foundation, as will be described later. One side 4A side of the side plate portion 4 is formed so as to be a rising portion of the equipment foundation as described later. Concrete is cast on the other surface 4B side of the side plate portion 4 as described later. The formwork member 1 is integrated after the concrete is poured.

The formwork member 10 is formed of, for example, concrete in a cubic shape. The formwork member 10 is arranged at four corners of the formwork member 1 assembled in a frame shape on the floor slab surface. The formwork member 10 is used as a part of a concrete formwork. The length of one side of the formwork member 10 is formed to be the same as the width of the bottom plate portion 2 and the side plate portion 4 of the formwork member 1.

The formwork member 10 is formed with a bottom surface portion 11, a top surface portion 16, and four side surface portions 12-15. The bottom surface portion 11 is adhered to the floor slab surface with an adhesive. The four side surface portions 12-15 are formed so as to have a height higher than the height required for the equipment foundation, as will be described later.

The pair of side surface portions 12 and 13 that are in contact with each other at right angles are formed so as to be corner portions of a rising portion of the equipment foundation, as will be described later. Concrete is cast on the pair of side surface portions 14 and 15 as described later. Since the four side surface portions 12-15 of the formwork member 10 to be integrated after the concrete is poured are formed in the same shape, the rising portion of the equipment foundation is the pair of side surface portions 12. Not limited to, and 13, it may be changed as appropriate depending on the arrangement relationship.

Next, a method of constructing a facility foundation formed by standing up from an existing floor slab surface will be described.

As shown in FIG. 3, the existing floor slab surface E is formed flat. On the floor slab surface E, for example, a plurality of formwork members 1 are arranged in a frame shape along the outer shape of the equipment foundation. Formwork members 10 are arranged at four corners in the area where the formwork member 1 is arranged. The formwork members 1 and 10 are adhered to the floor slab surface E at the time of arrangement.

In the formwork member 1, an adhesive is applied to the lower surface 2A of the bottom plate portion 2. The formwork member 1 coated with the adhesive is arranged at a preset position, and is fixed to the floor when the adhesive solidifies. As the adhesive, for example, an elastic adhesive, a urethane-based adhesive, or an epoxy-based adhesive having a proven track record in adhering concrete to each other is used. The area of the floor slab surface E surrounded by the formwork member 1 may be roughened in order to improve the integrity of the floor slab surface E and the equipment foundation before placing concrete. The bonding surface B between the floor slab surface E and the formwork member 1 may also be roughened before bonding in order to improve the integrity of the floor slab surface E and the equipment foundation.

In the roughing process, when the concrete of the floor slab surface E has already hardened, the surface of the floor slab surface E is made uneven by using a tool such as a water jet, a grinder, a sander, a hammer, or a bush hammer. Before the concrete on the floor slab surface E hardens, the surface is made uneven by using a broom, a bamboo brush, or the like. The lower surface 2A of the formwork member 1 may also be roughened. When the formwork member 1 and the floor slab surface E are not required to be integrated, the floor slab surface E may be cleaned to remove dust and the like. After the adhesive is solidified, the formwork T of the equipment foundation is formed by the formwork members 1 arranged in a frame shape.

As shown in FIG. 5, in the formwork T, the reinforcing bar S is arranged in the area X surrounded by the formwork member 1. Reinforcing bars S are arranged in a grid pattern, for example. The reinforcing bars S are arranged so as to bridge the bottom plate portions 2 of the pair of formwork members 1 facing each other, for example. As a result, the reinforcing bars S are arranged with a gap above the floor slab surface E.

As shown in FIG. 6, concrete C is placed in the area X. The concrete C is filled, for example, to the same height as the side plate portion 4. The surface of the concrete C may be smoothed by moving a trowel arranged so as to bridge the upper ends of the pair of side plate portions 4, for example. When the concrete C is hardened, the formwork member 1, the reinforcing bar S, and the concrete are integrated to construct the equipment foundation 20. The equipment foundation 20 is formed in a plate shape. The equipment foundation 20 is formed with a rising portion 21 in which the side plate portion 4 of the formwork member 1 rises upward from the floor slab surface E.

Next, the adhesive strength between the floor slab surface E and the formwork member 1 will be described.

As the design external force applied to the equipment foundation, for example, seismic load, vibration during equipment operation, lateral pressure during concrete placement, etc. are assumed. The adhesive area between the floor slab surface E and the formwork member 1 is set so that the adhesive strength resists the overturning moment generated in the equipment by the external force. The overturning moment is a moment generated by an overturning motion generated in equipment during an earthquake.

Against overturning moment M _T that occur equipment during an earthquake, indicating whether frame members 1 and the floor slab surface E and the adhesive strength can be ensured design example of determining below. Against overturning moment generated in the equipment, the adhesive strength of the adhesive Uwamaware if equipment than the moment of resistance M _A is designed to avoid tipping. Overturning moment M _T is calculated, for example, as shown in the following equation (1).
_{M T = K H × W ×} L 1 (1)
However, horizontal seismic intensity for design: K _H
Equipment weight: W
Vertical distance from the center of rotation to the center of gravity: L ₁

Resistance moment M _A is, for example, is calculated as shown in the following equation (2).
_{M A = S × σ a ×} F × L 2 (2)
However, the area of the adhesive part: S
Allowable tensile strength of the adhesive used: σ _a
Adhesive factor of safety: F
Distance from the adhesive part to the center of rotation: L ₂

As shown in FIGS. 7 and 8, facility basis, to set the value of the equipment, to calculate the tipping moment M _T and moment of resistance M _A.
Equipment weight: W = 1000kg (9800kN)
Equipment dimensions: 800 ^L x 1500 ^D x 1000 ^H
Equipment foundation dimensions: 1000 ^L x 1700 ^D x 100 ^H
Allowable tensile strength of the adhesive used: σ _a = 1.0 N / mm ²
Adhesive safety factor: F = 0.25
Bottom width of formwork member: 50 mm
Horizontal seismic intensity for design: K _H = 2.0
The falling direction of the equipment and the direction of the arrow, ignoring the weight of the equipment foundation, overturning moment M _T of the equipment is calculated by the following equation (3).
_{M T = 2.0 × 9800 × 500} = 9.8 × 10 6 Nmm (3)
Resistance moment _{M A} is calculated by the following equation (4).
MA = 50 × 1500 × 1.0 × 0.25 × 875 = 16.4 10 ⁶ Nmm (4)

According to equation (3) and (4), next to M _A> M _T, relative to overturning moment caused by the design load of the equipment, the resistance moment increases, sufficient adhesive strength can be ensured by using an adhesive The equipment foundation can be constructed.

As described above, according to the method of constructing the equipment foundation, it is possible to eliminate the need for the construction of exposing the reinforcing bars from the floor slab surface in advance. According to the method of constructing the equipment foundation, the process of bending and temporarily placing the reinforcing bar exposed from the floor slab surface is not required, and the flat floor slab surface can be used as a work space until the equipment foundation is constructed. Work efficiency can be improved and safety can be improved.

According to the method of constructing the equipment foundation, since concrete is cast on the formwork member 1 and integrated to construct the equipment foundation, there is no process of installing the formwork, re-bending the reinforcing bars, and removing the formwork, and the work manpower The construction period can be shortened and the construction cost can be significantly reduced. According to the method of constructing the equipment foundation, the work related to the construction can be easily performed, the skilled worker is not required, and the unit price of labor cost can be reduced.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned one embodiment, and can be appropriately modified without departing from the spirit of the present invention. For example, in the form T, the form member 1 is formed in an L cross-sectional shape, and the form member 10 formed in a cube is arranged at a corner portion. The formwork T may have a height required for the equipment foundation and a bottom surface width that can secure a predetermined bonding area, and the formwork member may be formed in a square cross-sectional shape.

1 Formwork member, 2 Bottom plate part, 3 One side surface, 4 Side plate part, 10 Formwork member, 11 Bottom part, 12-15 Side part, 16 Top surface part, 20 Equipment foundation, 21 Rising part, B Adhesive surface, C concrete , E floor slab surface, S rebar, T formwork

Claims (7)

It is a facility foundation formed by standing up from the existing floor slab surface.
A formwork member bonded to the floor slab surface along the outer shape of the equipment foundation,
Reinforcing bars arranged in the area surrounded by the formwork members,
An equipment foundation comprising the formwork member and a rising portion formed by integrating the reinforcing bar and concrete in the region. The formwork member has an adhesive area set so that the adhesive strength opposes the force generated by the external force acting on the equipment fixed to the equipment foundation.
The equipment foundation according to claim 1. The adhesive area is set so that the adhesive strength opposes the overturning moment generated in the equipment by the external force.
The equipment foundation according to claim 2. The formwork member is formed at a height required for the equipment foundation.
The equipment foundation according to claim 3. The formwork member is made of precast reinforced concrete.
The equipment foundation according to any one of claims 1 to 4. It is a method of constructing a facility foundation that is formed by standing up from the existing floor slab surface.
A step of adhering and arranging the formwork member on the floor slab surface along the outer shape of the equipment foundation.
The process of arranging the reinforcing bars in the area surrounded by the formwork members,
A method for constructing an equipment foundation, which comprises a step of placing concrete in the area and integrating the formwork member, the reinforcing bar, and the concrete. A step of roughening the area before placing the concrete is provided.
The method for constructing a facility foundation according to claim 6.

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