JP2501709B2 - Foundation structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foundation structure using a precast concrete foundation which has been formed in a factory or the like in advance and installed at a construction site to form a house or the like.

[0002]

2. Description of the Related Art Generally, a continuous foundation of a wooden house or the like extends to the left and right at the lower part of the foundation upright to support the foundation upright of a rectangular plate that supports the base of the house. And a footing portion which is formed of a concrete block integrally formed in an inverted T-shape in cross section.
Conventionally, such a continuous foundation has been processed on site through processes such as excavation of root cutting holes, formation of ground work at the bottom of root cutting holes, building of formwork, reinforcement, and concrete placement. It was made of poured concrete.

Further, in recent years, in place of the cast-in-place concrete foundation having many steps as described above, a precast concrete foundation which is previously formed into a reverse T-shape in a factory or the like may be used. .

[0004]

By the way, in the above foundation, when the footing portion supporting the rising portion of the foundation is insufficient in rigidity and it is necessary to increase the rigidity of the footing portion, the concrete forming the footing portion is thickened. Was. At this time, the width of the footing portion is determined according to the weight of the house supported by the foundation (including the weight of the foundation), so the concrete of the footing portion is made thicker and the weight of the foundation increases, It was necessary to widen the footing portion.

In a relatively lightweight wooden house, the weight of the foundation, which is a lump of concrete, is large. Therefore, as described above, the increase in the width of the footing portion due to the increase in the weight of the foundation becomes relatively large. Therefore, in order to build a house of a size just within a limited area of land, it is necessary to reduce the floor space of the house by the amount that the width of the footing portion increases.

Further, since the rigidity of the footing portion is increased, the thickness and width of the footing portion are increased as described above, so that the weight of the foundation is significantly increased. As another method of strengthening the rigidity of the footing part that supports the foundation rising part, make the center part of the footing part thicker and make both side edges of the footing part thinner so that the top surface of the footing part is inclined. Methods of forming are known.

However, constructing a foundation having such an inclined surface with cast-in-place concrete is a laborious task due to the fluidity of the concrete before hardening.
For example, once the cast concrete has begun to harden and its fluidity becomes low, it is necessary to shape it with a trowel or the like to provide an inclination on the upper surface of the footing portion.

Further, the above construction method also inevitably increases the weight of the foundation to some extent. Therefore, strengthening the rigidity of the footing part leads to an increase in the weight of the foundation, and when the foundation is made of precast concrete, the transportation volume from the factory to the site is reduced and a large truck is used. There was a problem such as requiring In addition, since the precast concrete foundation was originally heavy, it was difficult to load and unload it during construction and construction work.

The present invention has been proposed in view of the above circumstances, and an object thereof is to achieve light weight and high rigidity,
It is to provide a foundation structure that is easy to construct.

[0010]

A base structure of the present invention is formed in advance in a factory or the like and has a substantially rectangular base footing portion in plan view, and a base footing portion formed in advance in a factory or the like, and on the base footing portion. Is a base structure that is installed in the main body and is configured in an inverted T-shape in cross section with a substantially rectangular base rising portion as a side view,
It comprises a box-shaped base portion having an open upper surface, and a plurality of support plates spaced apart in the length direction of the base portion and provided on the base portion at a substantially right angle to the length direction of the base portion. The support plate is formed in a substantially triangular shape, and a cutout portion is formed in a central portion thereof, and the base upright portion has a lower portion thereof fitted into the cutout portion of the support plate and supported by the support plate. It is installed inside the box-shaped base, and the base is installed.
A plurality of rod-shaped members are provided on the ground
The base is placed on the bottom of the base.
An opening is formed between the base and the ground from the opening
Concrete is flowed in, and further the bottom edge of the foundation upright
Concrete is placed in the base to embed the
That is the means for solving the above problems.

[0011]

Further, in the foundation structure of the present invention, a groove along a horizontal direction is formed in a portion embedded in concrete cast in the base portion on the lower side surface of the foundation rising portion. It was used as a solution to the problem.

[0013]

According to the structure of the invention described in claim 1, the footing portion is composed of a box-shaped base portion having a hollow inside, and a supporting plate arranged at intervals in the longitudinal direction of the footing portion, Further, since the support plate serves as a reinforcing rib against the force applied to the foundation, the footing portion can be made lightweight and highly rigid.

The concrete cast inside the base portion only receives the ground pressure of the bottom surface of the footing portion divided into a small area by the support plate and the foundation upright portion, and can be formed thin. In addition, the footing portion after construction can be made lightweight, and the width of the footing portion at the design stage can be made small. Ma
In addition, concrete poured into the inside of the base flows from the bottom opening of the base between the base and the bottom, increasing the adhesion between the ground and the foundation, preventing slipping between the foundation and the ground, and further It is possible to reduce the weight.

According to the second aspect of the present invention, by providing a groove in a portion of the side of the foundation rising portion to be embedded in concrete, the foundation is divided into a footing portion and a foundation rising portion. Even if there is a pull-out stress on the foundation, the force applied to the upper part of the foundation is efficiently transmitted to the concrete portion in the base, and the whole foundation can cope with the pull-out stress.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 are drawings showing a basic structure of this embodiment. The basic structure of this embodiment is a precast concrete foundation upright 10 for supporting a base portion of a house or the like, and the foundation upright. A footing portion 20 made of precast concrete that supports 10 is mainly configured.

The foundation of this embodiment is to be installed on the earthwork 1 formed at the bottom of a root cutting hole (not shown), as in the prior art. On the groundwork 1, three steel rod-shaped members 2 ... Are arranged at equal intervals and parallel to each other along the length direction of the foundation. Further, the two outer bar-shaped members 2 and 2 are arranged on the inner side of both side edges of the footing portion 20 placed on the bar-shaped members 2 ... As described later, and the center bar-shaped member 2 is Footing section 20
It is arranged so that it comes to the approximate center. The rod-shaped members 2 are not limited to steel members as long as they are linear. Further, the rod-shaped members 2 may have an L-shaped cross section or a channel shape.

Then, the footing portion 20 is placed on the rod-shaped members 2. The footing portion 20 has a base portion 2 formed in a substantially rectangular shape in plan view as shown in FIG.
1 and a plurality of support plates 22 ... Which are arranged at equal intervals along the length direction of the base 21 are integrally formed on the base 21. The base 21 has a rectangular bottom plate 23.
And side plates 24, 2 which are vertically installed on both side edges of the bottom plate 23.
4 is formed into a box shape whose upper surface is opened and which is divided by the support plates 22.

Further, the bottom plate 23 is formed with rectangular openings 25, 25 on the left and right of the central portion of the bottom plate 23, respectively. That is, the bottom plate 23 has the openings 25, 25.
Allows the central plate portion 23a and the two side edge plate portions 23b, 2
It has a shape divided into 3b and 3b.

The support plate 22 is erected at a right angle to the length direction of the base portion 21 and connects the bottom plates 23 in the three-divided state. The bottom surfaces of the support plates 22 are integrally joined to the central plate portion 23a and the side edge plate portions 23b and 23b of the bottom plate 23, and at the openings 25 and 25 of the bottom plate 23, the central plate portion 23a. And the side edge plate portions 23b, 23b are flush with the bottom surfaces. The left and right ends of the support plates 22 are integrally connected to the side plates 24, 24 of the base 21 and are formed at substantially the same height as the side plates 24, 24. Further, the upper surfaces of the support plates 22 ... Are inclined surfaces that are higher than the side plates 24, 24 from both ends of the support plates 22 toward the center of the support plates 22. That is, the support plate 22 ...
Are formed in a substantially triangular shape when viewed from the front.

A rectangular notch 22a extending from the upper end of the support plate 22 to the upper surface of the center plate 23a of the bottom plate 23 is formed in the center of the support plate 22. That is, the support plate 22 is
It is configured to be divided into two by the cutout portion 22a. Further, the width of the cutout portion 22a is made slightly wider than the thickness of the foundation rising portion 10 so that the foundation rising portion fits into the notch portion 22a. In addition, the notch 22 of the support plate 22 into which the joint 11 of the foundation rise 10 described later is fitted.
The width a is widened corresponding to the thickness of the joint 11.

Then, the foundation stand 10 is formed in the notches 22a.
And the bottom surface of the foundation upright 10 is in contact with the top surface of the central plate portion 23a of the base portion 21, concrete is poured into the inside of the base portion 21, and the cast-in-place concrete layer 2
6 are formed. The concrete has a base 21 and a bottom plate 2
It flows from the openings 25, 25 of the No. 3 between the bottom surface of the base 21 and the top surface of the earthwork 1 and acts as a grout material between the base 21 and the earthwork 1. Further, the concrete flowing out from the openings 25, 25 is restricted from flowing out by the side surface (not shown) of the root cutting hole. The height of the cast concrete layer 26 is substantially the same as the height of the side plates 24, 24 of the base 21.

The foundation rising portion 10 is a rectangular plate body as viewed from the side. Grooves 12 and 12 are horizontally formed in a portion of the lower end of the foundation rising portion 10 which is embedded in concrete. The grooves 12, 12 are shear cotters, and are used to increase the efficiency of the force transmission between the concrete layer 26 and the foundation upright 10 which are cast by the concrete to be poured into the groove. It is a thing.

In addition, on both the left and right ends of the foundation upright 10,
A joint portion 11 (only one end of the foundation rising portion 10 is shown in FIG. 1) is formed to connect the plurality of foundation rising portions 10 and 10 to form a continuous foundation. The joint 11 is
In a state of protruding to one side surface side of the foundation rising portion 10, the thickness is increased, and the notch 13 opening to the upper surface, the lower surface and the end surface of the foundation rising portion 10 is formed, and has a substantially y-shape in plan view. Is formed in.

At the joints between the two foundation uprights 10 and 10, the foundation uprights 10 and 10 are abutted against each other with their end faces facing each other. Then, in a state in which both the notches 13 and 13 are put together, a plurality of reinforcing bars 14 are provided across the notches 13 and 13 of both foundation uprights 10 and 10.
(Only one is shown in phantom in FIG. 1) are horizontally arranged in the notches 13 and 13. And both foundations 1
Concrete is placed in the notches 0 and 10 in one piece.

A method of constructing a foundation to which the foundation structure of this embodiment is applied will be described below. First, the footing portion 20 and the foundation rising portion 10 are manufactured in a factory. Then, the footing portion 20 and the foundation rising portion 10 are transported from the factory to the construction site by a truck or the like. At this time, the foundation is the footing portion 20 and the foundation rising portion 1
The footing unit 20 is divided into 0 and
Since the inside thereof is formed in a substantially hollow box shape and the openings 25, 25 are formed in the bottom plate 23, it is extremely lightweight, and can be easily transported and loaded and unloaded. Construction can be performed.

Next, at the construction site, the root cutting hole and the groundwork 1 are formed as in the conventional case. Then, three bar-shaped members 2 ... Are installed on the earthwork 1. At this time, even if the groundwork 1 has some unevenness, the foundation can be easily installed horizontally by installing the rod-shaped members 2.

Next, the footing portion 2 is formed on the rod-shaped members 2.
Place 0. In addition, when the foundation is a relatively long continuous foundation, a plurality of footing portions 20 and 20 are connected and used. Next, the notch 22a of the support plate 22 is attached to the foundation stand 10
The foundation upright 10 is installed on the footing portion 20 such that the lower portions of the foundations fit together. Then, concrete is placed inside the base portion 21 of the footing portion 20. The poured concrete is used for the openings 25, 25 of the bottom plate 23 of the base 21.
Flows into the space between the base portion 21 formed by the rod upper members 2 ... And the groundwork 1. Then, the cast concrete layer 26 is cured and the root cutting holes are backfilled to complete the foundation construction.

According to the above-mentioned foundation structure, the force against the load of the upper structure (house) on the foundation is from the ground to the base 2
The concrete layer 26, the base portion 21, the support plate 22, and the foundation rising portion 10 which are cast in the structure 1 are transmitted in this order. In addition, when the house sways due to an earthquake, wind, or the like, the pulling force applied to the foundation upright portion 10 is transmitted to the concrete layer 26 cast in the base portion 21 via the grooves 12 and 12 serving as shear cotters. And transmitted to the base 21 and the support plate 22.

As described above, according to the basic structure of this embodiment, since the bar-shaped members 2 are installed on the earthwork 1 and the footing portion 20 is placed on the bar-shaped members 2, the horizontal level of the foundation can be easily adjusted. Can be matched. Also, the footing unit 20
Has a box-shaped base portion 21 and support plates 22 and has a substantially hollow interior, so that it can be made extremely lightweight and can be transported easily.

Further, in the footing portion 20, a plurality of support plates 22 ... Fitting the foundation rising portion 10 serve as reinforcing ribs of the footing portion 20 and also serve as reinforcing plates supporting the foundation rising portion 10, so that the foundation Can be made lightweight and highly rigid. Further, the concrete layer 26 cast in the base 21 only receives the ground pressure of the bottom surface of the base 21 divided into a small area by the support plates 22 ... , It can be thinner and lighter than the conventional footing part of the foundation.

Therefore, the footing portion 20 reinforced by the support plates 22 can be made lightweight and highly rigid even after concrete is placed therein,
At the design stage, the width of the footing portion 20 can be reduced. Therefore, when building a house of a very small size on a limited area of land, the area occupied by the footing portion 20 can be made small and the floor space of the house can be made large.

Even if the foundation is divided into the footing portion 20 and the foundation rising portion 10 by providing the groove 12 on the side surface of the foundation rising portion 10, when the foundation is subjected to pulling stress, The force applied to the foundation rising portion 10 is efficiently transmitted to the concrete layer 26 in the base portion 21, and the entire foundation can handle the pulling force. The shapes, dimensions, etc. of the respective constituent members shown in the above embodiment are examples, and can be variously changed based on design requirements and the like.
For example, the number of rod-shaped members 2, ..., The height, length, thickness, etc. of the foundation riser 10 can be changed according to the size of the house and the like.

[0034]

As described above in detail, according to the foundation structure of the present invention, the footing portion of the foundation can be made lightweight and highly rigid, and can be easily transported and constructed. it can. In addition, since the footing part can be made lightweight even after construction, the width of the footing part can be reduced, and the footing part can be used when building a house just barely on a limited area of land. The area occupied by the parts can be reduced.

Further, the horizontal level of the foundation can be easily adjusted by installing the rod-shaped member in advance under the footing portion. An opening is provided in the bottom plate of the base, and when pouring concrete into the base, concrete can be introduced between the base and the ground to enhance the adhesion between the bottom surface of the foundation and the ground, and in particular, Since it is not necessary to inject grout material or apply mortar or the like, the construction can be facilitated.

Further, even if the foundation is divided into the footing portion and the foundation rising portion, the pulling stress is applied to the foundation by providing the groove in the portion of the side portion of the foundation rising portion which is embedded in the concrete. When this happens, the force applied to the upper part of the foundation is efficiently transmitted to the concrete part inside the base,
The entire foundation can handle the pulling force.

[Brief description of drawings]

FIG. 1 is a perspective view showing a basic structure of the above embodiment.

FIG. 2 is a perspective view showing a footing portion of the basic structure.

[Explanation of symbols]

 1 Geotechnical work 2 Bar-shaped member 10 Foundation rise 12 Groove of foundation rise 20 Footing part 21 Base 22 Support plate 22a Support plate notch 23 Base bottom plate (bottom) 25 Bottom plate opening 26 Concrete cast layer

Claims (2)

(57) [Claims] 1. A base footing portion which is preliminarily formed in a factory or the like and has a substantially rectangular shape in a plan view, and a base footing portion which is preliminarily formed in a factory or the like and is installed on the base footing portion and which is substantially rectangular in side view. A basic structure having an inverted T-shaped cross-section mainly including a base rising portion, wherein the base footing portion has a box-shaped base portion having an open upper surface and a space in the longitudinal direction of the base portion. And a plurality of supporting plates provided on the base at substantially right angles to the length direction of the base, the supporting plate being formed in a substantially triangular shape and having a notch in the center thereof. parts are formed, the underlying raised portion, together with its lower part supported by the support plate is fitted in the notch of the support plate, is installed in the box-shaped in the base, the ground where the base is placed There are multiple rods on top
And the base is placed on the rod-shaped member, and the base has an opening formed at the bottom thereof.
Concrete flows between the base and the ground, and
In the base so as to bury the lower end of the foundation upright
Foundation structure characterized by concrete being cast . 2. The foundation rising portion is the lower portion of the side surface thereof.
In the part that is embedded in the concrete that was placed in the base,
Characterized by the formation of grooves along the horizontal direction
The basic structure according to claim 1.