JP3213721B2 - Building foundation reinforcement method and reinforcement 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 of a building, and more particularly to a method and a structure for reinforcing a foundation of a building for the purpose of strengthening the foundation of an existing wooden building.

[0002]

2. Description of the Related Art In recent years, the revision of the Building Standard Law and the like has made it possible to construct a wooden three-story house. However, when constructing a wooden three-story house by extension, unlike the case of a new construction, it is necessary to reinforce the existing two-story foundation to conform to the three-story standard.

[0003] As a conventional technique of such foundation reinforcement, for example, Japanese Patent Application No. 8-34467 (Japanese Patent Application Laid-Open No. 10-1689)
No. 02 publication). This is because, as shown in FIG. 4, in order to reduce the contact pressure acting on the cloth foundation 10, in order to increase the bottom area of the footing portion 10a, the base streak 11 is fixed to the rising portion 10b and the rising portion 10b is fixed. The reinforcing fiber-mixed high-strength high-fluidity concrete 12 is cast over the entire area surrounded by the square.

[0004]

However, the prior art has the following problems. (1) The high-strength and high-fluidity concrete 12 mixed with reinforcing fibers is expensive, and since it is cast over a wide area, the construction cost increases. (2) The concrete 1
Since 2 is to be cast over the entire area surrounded by the rising portion 10b, work and materials are wasted.

In view of the above problems, the present invention provides an efficient method of reinforcing a building foundation and a reinforcing structure in which only special parts are reinforced without using expensive special concrete. The purpose is to provide.

[0006]

That is, the invention according to claim 1 is a method for reinforcing a cloth foundation comprising a horizontal footing portion and a vertical rising portion, wherein a large number of metal members are provided in the middle of the rising portion. Providing a bottom or through horizontal hole,
Inserting a streak into each of the horizontal holes, holding the stairs so as to protrude on one or both sides of the rising portion, and covering the streak with the rising portion to a structurally necessary height. A step of pouring ordinary concrete on one or both sides of the building and forming an auxiliary footing having a fixed width along the rising portion. Further, the invention according to claim 2 is a cloth foundation comprising a horizontal footing portion and a vertical rising portion, and is inserted into a number of bottomed or penetrating horizontal holes provided in the middle of the rising portion, A streak held so as to protrude on one or both sides of the rising portion, and a fixed width which is cast to the structurally necessary height by covering the streak on one or both sides along the rising portion. And an auxiliary footing made of ordinary concrete.

According to such a reinforcing method and a reinforcing structure, an inexpensive ordinary concrete is used instead of an expensive special concrete as in the prior art, so that the construction cost can be kept low. In addition, instead of casting concrete over the entire area surrounded by the rising portion as in the related art, an auxiliary footing having a required width is formed along the rising portion,
Waste of materials and work can be reduced.

[0008]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the description, the same elements will be denoted by the same reference symbols, without redundant description.

1. Significance Adding an existing two-story building to a three-story building will increase the building weight, and if the base area of the foundation remains the same, the ground pressure of the foundation will increase. There is no particular problem if the increased contact pressure is still smaller than the bearing capacity of the supporting ground. However, if the contact pressure is larger than the bearing capacity, the ground cannot support the building and the building sinks. Therefore, this can be prevented by adding a foundation having a necessary bottom area. The present invention is based on such an idea, and has a meaning that the ground pressure does not exceed the ground strength by forming an auxiliary footing having a constant width along the rising portion of the foundation.

[0010] 2. Structure FIG. 1 is a perspective view illustrating an embodiment of a reinforcing structure for a building foundation according to the present invention. Here, reference numeral 10 indicates a cloth foundation to be reinforced, reference numeral 21 indicates a horizontal hole, and reference numeral 22
Denotes a streak, reference numeral 23 denotes ordinary concrete, and reference numeral 20 denotes an auxiliary footing composed of these. Hereinafter, the significance of the present invention will be clarified by detailing the configuration, operation, and the like of each of these components.

(1) Cloth Foundation The cloth foundation 10 is a lower structure that supports a building, and is a reinforcement target in the present invention. The cloth foundation 10 is composed of a horizontal footing portion 10a and a vertical rising portion 10b integrated with the footing portion 10a, and has an inverted T-shaped cross section as a whole. In addition, the cloth base 10 in the present invention may be either straight or unstripped, and
An eccentric cloth base having a V-shaped cross section may be used.

(2) Auxiliary footing The auxiliary footing 20 is added to the cloth foundation 10 to compensate for the shortage of the bottom area of the footing portion 10a and to reduce the contact pressure of the footing portion 10a.
It is composed of a horizontal hole 21, a streak 22 and ordinary concrete 23. As shown in FIG. 2, the auxiliary footing 20 is formed on both sides of the rising portion 10b of the fabric base 10 (FIG. 2A), and is formed on only one side (FIG. 2B). ).

Horizontal Hole The horizontal hole 21 is a penetrating hole provided at a fixed height in the middle of the rising portion 10b, and plays a role of inserting and holding the streak 22. This horizontal hole 21
0b, and therefore horizontally, with a diameter of
2 is determined according to the diameter. The height position of the horizontal hole 21 is determined so as to be lower than the upper surface of the auxiliary footing 20 by a predetermined height, and in the present embodiment, the height of the horizontal hole 21 is set to about 1/2 of the thickness of the auxiliary footing 20. 22 are arranged. The number of horizontal holes 21, that is, the number of inserted streaks 22, depends on the required auxiliary footing 20.
Is determined by structural calculation according to the reinforcing strength of the steel.

Although the horizontal hole 21 in the present embodiment penetrates the rising portion 10b, the present invention is not limited to this, and may be a bottomed hole that does not penetrate the rising portion 10b. In this case, the streak 22 is supported in a cantilever manner from the rising portion 10b.

The streak 22 is inserted and held in a horizontal hole 21 provided in the middle of the rising portion 10b, and is integrated with the ordinary concrete 23 to increase the strength of the auxiliary footing 20 and to reduce cracks in the auxiliary footing 20. It plays a role in preventing it. Therefore, the streaks 22 are made of ordinary concrete 23
In consideration of the adhesion to steel, deformed steel bars are desirable, and the diameter and number thereof are determined by structural calculations. Further, the length of the difference streaks 22 is determined so as to fit within the width of the auxiliary footing 20 to be formed. Therefore, the rising portion 10b
And projecting to both sides thereof, and the rising portion 10b
The length of the differential streaks 22 is naturally different between the case of being supported in a cantilever shape and the case of being supported.

As shown in FIG. 2 (b), the difference streaks 22, which are supported in a cantilever manner from the rising portion 10b, are formed by threading a thread groove at one end of the difference streaks 22. Nut 2
2a is fixed to the rising portion 10b by fitting. Further, as another embodiment, the difference rod 2 shown in FIG.
2 'can be used. This is composed of a deformed steel bar 22a 'having a predetermined length with irregularities formed on the outer peripheral surface, and a sleeve 22b' fixed to one end of the deformed steel bar 22a '. With the use of the difference rod 22 ', the sleeve 22b' can be fixed to the rising portion 10b in a cantilever fashion by simply driving the sleeve 22b 'into the horizontal hole 21 without using a fixing means such as an adhesive. .

Ordinary concrete The ordinary concrete 23 is a main part of the auxiliary footing 20, and covers the streak 22 and is integrated therewith to form the auxiliary footing 20. This ordinary concrete 2
3 is cast on the slab concrete 13 cast for the purpose of preventing moisture in the underfloor space, and the casting height and the casting width are the same as the diameter and the number of the streaks 22, and the cloth foundation 10 is effective. It is determined by structural calculation so that it can be reinforced. In addition,
The ordinary concrete in the present invention is not limited to the ordinary concrete in the narrow sense in the concrete engineering, and includes even a slightly modified composition thereof, but is excluded from the category of high-strength concrete and other apparently narrow ordinary concrete. Does not include special concrete.

3. Construction method Next, an embodiment of a method for reinforcing a building foundation according to the present invention will be described.

(1) First Step In the first step, a horizontal hole 21 for inserting a streak 22 is formed in the rising portion 10b of the foundation 10. This drilling work can be performed manually by a worker who has dived under the floor from the underfloor inspection port provided on the first floor using a concrete drill, core drill, etc. Send the robot and perform it remotely.

(2) Second Step In the second step, the streak 22 is inserted and held in the horizontal hole 21 formed in the rising portion 10b in the previous step. This work is also performed by a worker under the floor manually or by a remotely controlled industrial robot, as in the previous step.

(3) Third Step In the third step, the auxiliary footing 20 is constructed by placing the ordinary concrete 23 on the slab concrete 13 with required dimensions. At this time, it is necessary to previously lay a formwork for pouring the ordinary concrete 23, and it is desirable that this formwork is a discarded formwork that does not need to be dismantled and collected later. After pouring the ordinary concrete 23 into the form, curing is performed, and the form is disassembled and collected as necessary.

[0022]

As described above, according to the method and structure for reinforcing a building foundation according to the present invention, inexpensive ordinary concrete is used instead of expensive special concrete as in the past, so that the construction cost is kept low. be able to. Also,
Instead of casting concrete over the entire area surrounded by the rising part as in the past, an auxiliary footing of the required width is formed along the rising part, so that waste of materials and work can be reduced. In addition, it is possible to easily and efficiently reinforce the cloth foundation after the extension.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an embodiment of a building foundation reinforcement structure according to the present invention.

FIGS. 2A and 2B are longitudinal sectional views showing an embodiment of a reinforcing structure for a building foundation according to the present invention, wherein FIG. 2A shows auxiliary footings formed on both sides of a rising portion, and FIG. An auxiliary footing is formed on one side.

FIG. 3 is a perspective view showing a difference rod used in place of the difference muscle.

FIG. 4 is a perspective view showing a conventional reinforcing structure for a building foundation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Cloth foundation 10a ... Footing part 10b ... Rise part 11 ... Base streaks 12 ... High-strength highly fluidized concrete mixed with reinforcing fiber 13 ... Soil concrete 20 ... Auxiliary footing 21 ... Horizontal hole 22 ... Bar 22a ... Nut 22 '... Difference Reinforcing rod 22a '... deformed steel bar 22b' ... sleeve 23 ... ordinary concrete

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-42165 (JP, A) JP-A 8-60678 (JP, A) JP-A 10-168902 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) E02D 27/08 E02D 27/01

Claims (2)

(57) [Claims] 1. A method for reinforcing a fabric foundation comprising a horizontal footing portion and a vertical rising portion, wherein a plurality of bottomed or penetrating horizontal holes are provided in the middle of the rising portion; Inserting a streak into each of the horizontal holes, holding the stairs so that they protrude on one or both sides of the rising portion, and covering the streak to a structurally necessary height of the rising portion. A step of casting ordinary concrete on one or both sides and forming an auxiliary footing having a constant width along the rising portion. 2. A cloth foundation comprising a horizontal footing portion and a vertical rising portion, wherein the one side of the rising portion is inserted into a number of bottomed or penetrating horizontal holes provided in the middle of the rising portion. Or, a reinforcing bar held so as to protrude on both sides, and on one side or both sides along the rising portion, ordinary concrete of a fixed width which is cast to a structurally necessary height by covering the reinforcing bar, A reinforcement structure for a building foundation, comprising an auxiliary footing comprising: