JP2003013460A - Foundation structure in building and its construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the ground subsidence of a building while preventing the inclination or the like of the building, and to execute even a countermeasure to vibrations. SOLUTION: Buoyancy D, dKN/m<2> per a unit plane area by a foamed-resin bedrock 4 pushing away soil and sand buried to the soil and sand of a ground 2 and being arranged in a hole 3 is set at a value of approximately A+B-C+E and a+b-c+e as mentioned above in the section of the foamed-resin bedrock 4 corresponding to two and one-storied building sections. A and (a) represent load per the unit area of the building 1, B and (b) load per the unit area of a foundation 5 and C and (c) ground strength. E and (e) represent the load of an article having density smaller than soil. The inclination of the building 1 can be prevented by a uniform supporting by adjusting the size of the foamed- resin bedrock 4 buried to the ground 2 in response to load per the unit areas of the building 1 and the foundation 5 or the article having density smaller than soil, that is, buoyancy D and (d) obtained by removing soil and sand.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foundation structure for a building that can be constructed as a countermeasure for ground subsidence and a countermeasure for differential subsidence by building a building on the ground, and a construction method therefor.

[0002]

Conventionally, in a reinforcing structure and a reinforcing construction method of a foundation structure in a building as a countermeasure for ground subsidence or a countermeasure for uneven settlement, excavation of the lower side of the foundation structure in the building to remove earth and sand. A hole is provided, a foamed resin substrate is placed in this hole, and the foamed resin substrate is joined and integrated with an existing foundation structure. By replacing it with a resin concrete board, it becomes a lightweight basic structure, and it is possible to take measures to prevent ground subsidence of buildings.

However, although the conventional solutions can prevent the ground subsidence of the building, the building cannot be supported uniformly and the building may be inclined. This is because the bearing capacity across the foundation of the building is not uniform.

Therefore, an object of the present invention is to provide a foundation structure and a construction method for a building which can prevent the ground subsidence of the building as well as the inclination of the building and also prevent vibration.

[0005]

According to the invention of claim 1, there is provided a foundation structure in a structure in which a buoyancy base having a density lower than the density of the ground is buried under a foundation of the structure provided on the ground. The buoyancy per unit area of the foundation is made substantially equal to the value obtained by subtracting the ground strength per unit area from the load per unit area of the building and the foundation in the entire area of the foundation of the building. It is the basic structure of a building.

According to the structure of claim 1, the foundation can be adjusted in the entire area of the foundation of the building to uniformly support the building.

A second aspect of the present invention is the foundation structure for a building according to the first aspect, characterized in that the base is a foamed resin base or an object having a density lower than that of soil.

According to the second aspect of the present invention, the base is made of a foamed resin base or a material having a density lower than that of the soil, so that the density difference between the base and the soil can be increased and the strength can be secured.

A third aspect of the present invention is the foundation structure for a building according to the first aspect, characterized in that a foamed resin wall for absorbing vibration waves and / or reflecting vibration waves is embedded outside the foundation and the foundation. .

According to the third aspect, the vibration wave can be absorbed and / or reflected by the foamed resin wall.

A fourth aspect of the present invention is the foundation structure for a building according to the first aspect, characterized in that a drainage wall when groundwater is high is buried outside the foundation and the foundation.

According to the structure of claim 4, when the ground water is high, the water can be drained by the drain wall.

According to a fifth aspect of the present invention, the ground is excavated to remove the earth and sand, and then a foamed resin substrate or an object having a density lower than that of the soil is placed in the hole formed by removing the earth and sand, and then the foaming is performed. In the construction method of the foundation structure in the building where the foundation of the building is provided on the resin base or the one having a smaller density than the soil, the strength of the ground is measured before the excavation, and the buoyancy per unit area of the base is It is a construction method for a foundation structure in a building, wherein the load is made substantially equal to a value obtained by subtracting the ground strength per unit area from the load per unit area of the building and the foundation.

According to the structure of claim 5, the ground strength can be previously investigated and measured to accurately calculate the buoyancy of the foamed resin base material or a material having a density lower than that of the soil. It can be adjusted to evenly support the building.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in the first embodiment of FIG. 1, the ground strength of the ground 2 at the place where the building 1 having a part of two floors is installed is previously measured and investigated, and the ground 2 is excavated to form the hole 3
To form. Next, a foamed resin substrate 4 which is a buoyancy substrate having a density lower than that of the ground 2 is embedded in the hole 3. The foamed resin substrate 4 may be any one that is lightweight and has the required compressive strength, and may be a plastic foam or a foamed material having a density lower than that of the soil, which is an environmentally friendly material. Preferably there is. Although it depends on the structure of the building, it is generally 10 to 200 KN / square meter. Moreover, the density of the material is smaller than that of soil. Then, on the object 4 whose density is lower than that of the soil (not shown)
After installing, the concrete is poured into the frame to form the foundation 5.

By the way, since the building 1 is partly a two-story building, it has a two-story portion and a one-story portion with the boundary 1A interposed therebetween. Then, the load of the two-story portion of the building 1, and thus the load per unit area of the two-story portion, for example, the plane 1
The load per square meter is AKN / square meter, the plane load per unit area of the one-story portion, for example, the load per square meter is aKN / square meter. Further, the load of the portion corresponding to the two-story portion of the foundation 5, and thus the load per unit area of the foundation 5 corresponding to the two-story portion, for example, the load per square meter of the plane BKN / square meter, the unit of the one-story portion. The load of the foundation 5 per area, for example, the load of the foundation 5 per square meter is bKN / square meter. 2 of the ground 2 previously measured and surveyed here
The ground strength corresponding to the one-story part and the one-story part is C, c
Then, in the portion 4A corresponding to the two-story portion of the foamed resin base 4 or the one having a lower density than the soil, the foamed resin base 4A embedded in the earth and sand of the ground 2 to displace the earth and sand and arranged in the hole 3A or the soil The buoyancy per unit area DKN / square meter due to the low density is D = A
It becomes + B-C + E. EKN / square meter is the load per unit area of the foamed resin substrate 4A or the one having a smaller density than the soil. And foamed resin substrate 4A
Alternatively, the buoyancy D per unit area of a material having a density lower than that of soil is set to a value equal to or more than A + BC + E (D = A + BC + E or D> A + BC + E). In the case of D> A + B-C + E, the safety factor K is generally multiplied by a safety factor K of 1 or more and 2 or less, preferably 1 or more and 1.5 or less (D = K (A + B-C +
E)).

On the other hand, in the portion 4B corresponding to the one-story portion of the foamed resin substrate 4 or the one having a lower density than the soil, the foamed resin substrate 4B embedded in the earth and sand of the ground 2 and displaced in the hole 3B or placed in the hole 3B or The buoyancy force dKN / square meter per unit area of a material having a density lower than that of soil is d = a + bc + e. The eKN / square meter is the load per unit area of the foamed resin substrate 4B or a material having a density lower than that of the soil. Then, the buoyancy d per unit area of the foamed resin substrate 4B or a material having a density lower than that of the soil is equal to or greater than a + bc + e (d = a + bc + e or d> a + bc +).
e). In the case of d> a + bc + e, the safety factor k is generally 1 or more and 2 or less, preferably 1 or more and 1.5.
It is assumed that the following safety factor k is multiplied (d = k (a + b
-C + e)).

As described above, the portion 4 corresponding to the two-story portion of the foamed resin substrate 4 or the one having a smaller density than the soil
Since A requires a larger buoyancy than the portion 4B corresponding to the one-story portion, its depth L is larger than the depth 1 of the portion 4B. In addition, the portion 4 corresponding to the two-story portion of the foamed resin substrate 4 or the one having a smaller density than the soil
The connecting portion between the lower portion of A and the lower portion of the portion 4B corresponding to the one-story portion is formed with the inclined portion 4C so that the depth changes almost uniformly in order to avoid a rapid change in the sectional area. .

Furthermore, a foamed resin wall 7 for absorbing and / or vibrating vibrational waves is buried outside the foamed resin substrate 4 or an object having a density lower than that of the soil at a distance. The lower end 7A of the resin wall 7 is preferably arranged deeper than the lowermost end of the foamed resin substrate 4. When the groundwater level is high, a drainage wall may be provided together with or separately from the foamed resin wall 7 for absorbing and / or vibrating the vibrational waves.

Next, the operation of the above structure will be described. An object having a density lower than that of the foamed resin base 4 or soil is embedded in the ground 2, and a foundation 5 and a building 1 are provided on the foamed resin base 4 or an object having a density lower than the soil, and the load of the foundation 5 and the structure 1 is applied. By balancing the load of excavated sand on the ground 2, the increase of underground stress can be suppressed and a so-called floating foundation structure can be obtained. In this way, the load of earth and sand removed by excavation is increased to near the load of the building 1 and the foundation 5, and the settling stress is set by laying the foamed resin substrate 4 of a material having a smaller density than that of the earth or a material having a smaller density than the soil. It is possible to prevent an increase in the height of the building 1 and to suppress the subsidence of the building 1 even if the ground 2 is soft and maintain the stability. Further, when a vibration due to a road or an earthquake occurs, the foamed resin wall 7 absorbs or reflects the vibration to prevent the vibration from being transmitted to the building 1 or the foundation 5 side.

As described above, in the above-described embodiment, the foamed resin substrate 4 corresponding to the two-story portion or the portion having a density lower than that of the soil is embedded in the soil of the ground 2 to displace the soil and dispose in the hole 3A. The buoyancy per unit area DKN / square meter by the foamed resin substrate 4A is set to A as described above.
+ B-C + E or K (A + B-C + E), one
In the portion corresponding to the floor portion, the foamed resin substrate 4 is buried in the soil of the ground 2 and is pushed away to dispose of the sand and placed in the hole 3B.
The buoyancy per unit area dKN / square meter by B or the one whose density is smaller than soil is a + b-c + e or k (a
+ B-c + e) as a value, the size of the foamed resin substrate 4 embedded in the ground 2 according to the load per unit area of the building 1 and the foundation 5, and thus the buoyancy D obtained by removing the sand and sand,
By adjusting d, it is possible to uniformly support and prevent the building 1 from tilting.

By embedding a foamed resin wall 7 for absorbing or absorbing vibration waves on the outside of the base 4 and the foundation 5, vibrations due to roads or earthquakes are absorbed or absorbed to protect the building 1, etc. can do.

Moreover, the ground 2 is excavated to remove soil,
Then, after placing the foamed resin substrate 4 or an object having a smaller density than the soil in the hole 3 formed by removing the earth and sand, the foundation of the building 1 is placed on the foamed resin substrate 4 or an object having a lesser density than the soil. In the construction method of the foundation structure in the building provided with 5, the ground strength of the ground 2 is measured and investigated in advance before the excavation, and the buoyancy D, d per unit area of the base 2 is calculated as the building 1 and the foundation. Load per unit area of 5, A, B,
It is almost equal to the value obtained by subtracting the ground strength per unit area C and c from a and b (A + B-C + E) or K (A + B-C +
E), a + b-c + e or k (a + b-c + e),
The buoyancy D, d per unit area of the base 2 can be accurately calculated to accurately support the building 1.

Moreover, when the groundwater level is high, a drainage wall can be provided together with or separately from the foamed resin wall 7 for absorbing and / or reflecting the vibrational waves, so that drainage can be favorably carried out. The floating foundation structure described above can be secured.

FIG. 2 shows a second embodiment of the first embodiment.
The same parts as those in the embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In the second embodiment, the lower part of the portion 4A corresponding to the two-story portion and the portion 4 corresponding to the one-story portion in the foamed resin substrate 4 or the one having a density smaller than the soil.
The connection portion with the lower portion of B is formed such that the depths L and l change stepwise with a boundary 1A between the two-story portion and the one-story portion as a boundary.

In this way, the connecting portion between the lower portion of the portion 4A corresponding to the two-story portion and the lower portion of the portion 4B corresponding to the one-story portion in the foamed resin substrate 4 or the one having a density lower than the soil is stepwise. By doing so, the two-story portion and the one-story portion can be smoothly supported.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, since the buoyancy base may be provided on the entire bottom surface of the foundation of the building corresponding to the shape of the building, the buoyancy base is variously deformed according to the shape of the building.

[0028]

According to the invention of claim 1, there is provided a foundation structure for a structure in which a buoyancy base smaller than the density of the ground is buried under the foundation of the structure provided on the ground. The buoyancy per unit area of the foundation is substantially equal to the value obtained by subtracting the ground strength per unit area from the load per unit area of the building and the foundation in the entire bottom surface of the building. It is a foundation structure, and the foundation can be adjusted in the entire area of the foundation of the building to eliminate the risk of the building leaning.

The invention according to claim 2 is the foundation structure in a building according to claim 1, characterized in that the base is a foamed resin base or an object having a density lower than that of the soil, and has a large density difference from the earth and sand. Therefore, the structure can be surely supported.

A third aspect of the present invention is the foundation structure for a building according to the first aspect, characterized in that a foam resin wall for absorbing vibration waves or reflecting vibration waves is embedded outside the foundation and the foundation. The vibration wave can be absorbed or reflected by the foamed resin wall to protect the building from the vibration wave.

The invention according to claim 4 is the foundation structure in a building according to claim 1, characterized in that a drainage wall when groundwater is high is buried outside the foundation and the foundation.
A floating foundation structure can be secured by draining water.

According to a fifth aspect of the present invention, the ground is excavated to remove the earth and sand, and then a foamed resin substrate or an object having a density lower than that of the soil is placed in the hole formed by removing the earth and sand, and then the foaming is performed. In the construction method of the foundation structure in the building where the foundation of the building is provided on the resin base or the one having a smaller density than the soil, the strength of the ground is measured before the excavation, and the buoyancy per unit area of the base is A method for constructing a foundation structure in a building, which is substantially equal to a value obtained by subtracting the ground strength per unit area from the load per unit area of the building and the foundation, which is more dense than a foamed resin base or soil. The buoyancy of small objects can be accurately calculated, and the foundation of the building can be adjusted to uniformly support the building.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

[Explanation of symbols]

1 building 2 ground 3 holes 4 Foamed resin board (buoyancy board) 5 basics 7 Foamed resin wall A a B b load C c Ground strength D d buoyancy

Claims (5)

[Claims] 1. A foundation structure in a structure in which a buoyancy base having a density smaller than that of the ground is embedded in a lower portion of the foundation of the structure provided on the ground, and the base is provided over the entire bottom surface of the foundation of the structure. The buoyancy per unit area is substantially equal to the value obtained by subtracting the ground strength per unit area from the load per unit area of the building and the foundation, the foundation structure in the building. 2. The foundation structure for a building according to claim 1, wherein the base is a foamed resin base or an object having a density lower than that of soil. 3. The foundation structure in a building according to claim 1, wherein a foamed resin wall for absorbing vibration waves or reflecting vibration waves is embedded outside the foundation and the foundation. 4. A drainage wall when groundwater is high is buried outside the foundation and the foundation.
Foundation structure of the described building. 5. Excavating the ground to remove soil, and then
In a structure in which a foam resin substrate or a material having a density lower than that of soil is placed in the hole formed by removing the earth and sand, and then a foundation of the building is provided on the foam resin substrate or a material having a density lower than the soil. In the construction method of the foundation structure, the strength of the ground was measured before the excavation, and the buoyancy per unit area of the foundation was subtracted from the load per unit area of the building and the foundation minus the ground strength per unit area. A construction method for a foundation structure in a building, which is characterized in that it is approximately equal to the value.