JP2018115462A - Mat foundation for housing adaptable to liquefied and soft ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mat foundation for a housing allowing for prevention of compressive strain settlement of the housing when ground is liquefied, and a method of forming the mat foundation.SOLUTION: A mat foundation 1 for housing having an entrance, a kitchen, a bath, a toilet, and a living room is provided, comprising a slab part 2 and an upstanding part 3a upstanding from the slab part. The slab part includes a bottom board part 2a having an outer circumference having predetermined shape and extending along a design ground line GL, and an outer circumferential underground beam part 2b protruding downward from an outer circumferential part of the bottom board part and all along the outer circumferential part. A dimension D1 from a lower face of an intermediate portion 4 being a portion located inside the outer circumferential underground beam part in the bottom board part to a lower edge of the outer circumferential underground beam part is 0.3 m or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a solid foundation for a house that can cope with liquefaction and soft ground, and a method for producing the foundation.

  Conventionally, when a house is constructed on soft ground, it is known that the foundation of the house is a solid foundation.

  In addition, with regard to the depth of the foundation of the house, for example, the design and construction standards of the Housing Liability Guarantee Insurance Corporation Housing Compensation Organization (currently Housing Compensation Organization Co., Ltd.) are known (see Non-Patent Document 1). This design standard is the basis of other insurance companies. On page 40 of this design standard, a basic cross-sectional view is described, and “the depth of penetration should be 240 mm or more from the ground and the freezing depth or more.”

Housing Warranty Insurance Corporation Housing Compensation Organization “2012 version Mamorisui Insurance Design and Construction Standards / Commentary” (especially page 40)

  However, no specific proposal has been made regarding the design and construction standards regarding measures for liquefaction of the ground.

  The present invention was made in order to solve the problems associated with liquefaction of the ground, and provides a solid foundation for a house capable of preventing the sinking of the house when the ground is liquefied and a method for producing the foundation. Objective.

  In order to solve the above-mentioned problem, a solid foundation according to an aspect of the present invention is a solid foundation of a house having an entrance, a kitchen, a bath, a toilet, and a living room, and rises from the slab portion and the slab portion. A slab portion having a predetermined shape outer periphery, extending from a plate-shaped bottom plate portion extending along a design ground line, and an outer peripheral portion of the bottom plate portion, to the entire periphery of the outer peripheral portion. The outer underground beam portion protruding downward, and from the lower surface of the intermediate portion that is a portion located inside the outer peripheral underground beam portion in the bottom plate portion to the lower end of the outer circumferential underground beam portion The dimension is 0.3 m or more.

  According to this structure, the outer periphery underground beam part of a solid foundation and the intermediate part located inside the outer periphery underground beam part in a bottom board part form the recessed part (henceforth downward recessed part) opened below. And the dimension from the lower surface of the intermediate part of a bottom board part to the lower end of an outer periphery underground beam part is equivalent to the depth of this downward recessed part. Then, a crushed stone industry was created in the planned construction site of the house, a sand and gravel layer was formed on the portion other than the outer periphery of the crushed stone industry, and an outer ground underground beam was formed on the outer periphery of the crushed stone industry. When the solid foundation is provided so that the lower end portion of the portion is located and the downward concave portion is positioned on the sand / gravel layer, the depth of the downward concave portion is 0.3 m or more. It can be filled with sand and gravel layers with a thickness of 3m or more. As a result, even if the ground is liquefied, surplus water rising in the downward recess can be absorbed by the sand / gravel layer in the downward recess, so that the sinking of the house can be prevented.

  The penetration depth, which is a dimension from the design ground line to the lower end of the outer peripheral underground beam portion, may be 0.4 m or more.

  According to this configuration, since the dimension from the design ground line to the lower surface of the intermediate portion of the bottom plate portion is 0.1 m or more, the necessary strength of the bottom plate portion can be ensured.

  A pipe having a predetermined number of ends or more opened per predetermined area may be provided in the bottom plate portion so as to penetrate the bottom plate portion in the vertical direction over the entire surface of the bottom plate portion.

  According to this configuration, when the excess water generated by liquefaction rises in the sand / gravel layer in the downward recess of the bottom plate, the air in the sand / gravel layer in the downward recess is discharged from the pipe having both ends opened. Therefore, the sand / gravel layer can easily absorb surplus water. As a result, the sinking of the house can be suitably prevented.

  The bottom plate portion has an outer periphery with a corner shape, and an outer periphery rising portion is provided on the outer periphery of the bottom plate portion over the entire periphery of the bottom plate portion, and the outer periphery is located at the corner of the bottom plate portion. An intermediate rising portion may be provided so as to connect to the rising portion.

  According to this configuration, since the building having the entrance corner is fixed on the outer periphery rising portion of the outer peripheral shape having the entrance corner, the outer periphery rise portion (hereinafter referred to as the entrance corner rise) located at the corner of the entrance corner at the time of an earthquake. Torsional moment occurs. However, since the intermediate rising portion supports the entering corner rising portion, damage to the entering corner rising portion due to the twisting moment can be prevented.

  The bottom board portion has an outer periphery with a shape having a protruding corner, and the rising portion has an outer corner along the outer periphery of the bottom plate portion except for the protruding corner portion in a plan view, and has an entering corner at the protruding corner portion. The outer periphery rising part may be provided so that it may have a shape outer periphery and may stand up from the bottom board part.

  According to this configuration, since the building having the corner is fixed on the outer peripheral rising portion having the outer corner shape having the corner, a twisting moment is generated in the corner rising portion at the time of an earthquake. However, since the outer underground underground beam portion at the exit corner supports the rising corner rising portion, damage to the rising corner rising portion due to the twisting moment can be prevented.

  The dimension from the lower surface of the intermediate part of the bottom board part to the lower end of the outer periphery underground beam part may be 0.3 m or more and 1.0 m or less.

  According to this configuration, it is not expected that surplus water will rise beyond 1.0 m from the crushed stone industry, so that it can be safely absorbed by the sand / gravel layer in the downward recess.

  The depth of penetration may be 0.4 m or more and 1.1 m or less.

  According to this configuration, it is not expected that surplus water will rise beyond 1.0 m from the crushed stone industry, so that it can be safely absorbed by the sand / gravel layer in the downward recess.

Further, a method for creating a solid foundation for a house according to another aspect of the present invention is a method for creating a solid foundation for a house using any one of the solid foundations for a house described above. A step of creating a crushed stone industry on the ground, a step of creating a sand / gravel layer composed of at least one of sand and gravel on a portion excluding the outer periphery of the crushed stone industry, and Providing the solid foundation so that a lower end portion of the outer peripheral underground beam portion is positioned on the outer peripheral portion, and an intermediate portion of the bottom base portion is positioned on the sand / gravel layer,
The thickness of the sand / gravel layer under the intermediate portion of the bottom board is 0.3 m or more.

  According to this configuration, since the downward concave portion of the bottom plate portion is filled with a sand / gravel layer having a thickness of 0.3 m or more, even if the ground liquefies due to an earthquake, excess water rising to the downward concave portion is contained in the downward concave portion. Can be absorbed by sand and gravel layer. As a result, the sinking of the house can be prevented.

  A thickness of the sand / gravel layer under the middle portion of the bottom base portion of the solid foundation may be not less than 0.3 m and not more than 1.0 m.

  According to this configuration, it is not expected that surplus water will rise beyond 1.0 m from the crushed stone industry, so that it can be safely absorbed by the sand / gravel layer in the downward recess.

  INDUSTRIAL APPLICABILITY The present invention has an effect that it is possible to provide a solid foundation for a house that can prevent the sinking and sinking of the house when the ground is liquefied and a method for producing the foundation.

1A and 1B are a perspective view and a partial cross-sectional view showing a configuration of a solid foundation for a house according to Embodiment 1 of the present invention. FIG. 2 is a partial cross-sectional view showing a method for building a solid foundation for a house using the solid foundation for the house shown in FIG. FIG. 3: is the top view and partial sectional view which show the structure of the solid foundation of the house based on Embodiment 2 of this invention. FIG. 4: is the top view and partial sectional view which show the structure of the solid foundation of the house based on Embodiment 3 of this invention. FIG. 5: is the top view and partial sectional view which show the structure of the solid foundation of the house based on Embodiment 4 of this invention.

(Knowledge of the present invention)
The present inventors have intensively studied to solve problems associated with liquefaction of the ground, specializing in houses among various buildings. In the process, the following knowledge was obtained.

  The inventors of the present invention are the authors of Goji Kunio's paper “The formation of water film and the effect on ground stability during liquefaction due to the stratified structure of the sand layer (Application Geology, Vol. 41, No. 2, pp. 77-86, 2000). ”. Hereinafter, this paper is abbreviated as “national paper”.

  In this paper, two types of model experiments are conducted on the effect of the stratified structure often seen in sand ground on the behavior during liquefaction. First, in a liquefaction experiment of a one-dimensional loose saturated sand layer that simulates a stratified structure, pore water squeezed from the bottom immediately below the low-permeability layer contained in the sand layer is temporarily stored, and a water film is easily formed. It has been shown that. When a water film is generated in a heterogeneous sand layer by a vibration test on the model slope, the flow failure of the ground continues even after the end of the vibration, as was often seen in past earthquake damage, and discontinuous along the water film. Has been shown to occur. Further, it has been found that when the low water permeability layer is broken by the osmotic force, the upper layer is locally liquefied and destabilized. In other words, in this paper, the liquefaction mechanism in the stratified structure of sand ground is clarified qualitatively. And especially from the experimental results for sand layers containing silt seams (low water permeability layers), it can be read that the amount of subsidence of sand layers in this simulated liquefaction is 3.7 cm (page 79, Fig. 5 (a)). Silt seam).

  Since this numerical value of subsidence is based on an experiment using a model, it cannot be applied to actual liquefaction of the ground as it is. However, the present inventors have found that specific numerical values relating to liquefaction whose qualitative mechanism has been elucidated in this way can be effectively applied to actual ground liquefaction if the safety factor is expected.

  The present invention has been made based on such knowledge.

  Hereinafter, embodiments of the present invention embodying these findings will be described with reference to the accompanying drawings. In the following description, the same or corresponding elements are denoted by the same reference numerals throughout all the drawings, and redundant description thereof is omitted. In the following, in order to facilitate understanding of the present invention, the drawings are arranged as follows. In the following drawings, elements not related to the present invention may be omitted. Further, the following drawings may be exaggerated for easy understanding, and the dimensional ratio of the object is not always accurate. Also, the drawings may not exactly match each other.

(Embodiment 1)
[Structure of solid foundation]
FIG. 1 is a diagram illustrating a configuration of a solid foundation for a house according to Embodiment 1 of the present invention, an upper diagram is a perspective view, and a lower diagram is a partial cross-sectional view of part A of the upper diagram. . This partial cross-sectional view shows a vertical cross section along the horizontal direction of the solid foundation in part A. Here, in this application, it defines as follows. “Housing” means a building having a front door, a kitchen, a bath, a toilet, and a living room. “Housing” includes a foundation and a building body fixed on the foundation. In addition, the size of the foundation structure of the building is represented by “m” in accordance with the metrology law prescribed in Article 3 of the Patent Law Enforcement Regulations. In addition, the concept of “entrance” and “exit” used for the building body is also used for the foundation.

  Referring to FIG. 1, a solid foundation (hereinafter simply referred to as a solid foundation) 1 of a house includes a slab part 2 and rising parts 3 a and 3 b (see FIG. 4) rising from the slab part 2. Although the material of the solid foundation 1 is not specifically limited, For example, it is the product made from the concrete by which the reinforcing bar was arrange | positioned inside.

  In fact, the rising portions 3a and 3b may be formed with recesses on the upper surface and openings on the side surfaces, but are simplified in FIG. The rising portions 3a and 3b are provided according to the partition between the outer peripheral rising portion 3a corresponding to the outer periphery of the base of the building main body (not shown) and the building main body, and are intermediate risings that connect two appropriate portions of the outer peripheral rising portion. Part 3b (see FIG. 4). In FIG. 1, only the outer peripheral rising part 3a corresponding to the outer periphery of the building main body is shown for easy understanding of the invention.

  The slab part 2 includes a bottom board part 2a and an outer peripheral underground beam part 2b. The bottom board part 2a has a predetermined-shaped outer periphery. Here, it has a rectangular outer periphery with a corner. The outer peripheral shape of the bottom plate portion 2a basically matches the outer peripheral shape of the outer peripheral rising portion, but may not match as in the fourth embodiment described later. The bottom board part 2a is formed in the plate shape extended along the design ground line GL.

  The outer periphery underground beam part 2b is provided so that it may protrude below from the outer peripheral part of the bottom board part 2a over the perimeter of the said outer peripheral part. In addition, you may provide the intermediate underground beam part which connects two appropriate places of the outer periphery underground beam part 2b. The cross-sectional shape of the outer peripheral underground beam portion 2b is arbitrary. Typically, the outer peripheral underground beam portion 2b is formed in a trapezoidal shape in which one base angle is a right angle downward. Typically, the outer peripheral surface of the outer peripheral rising portion 3a, the outer base surface 2a of the slab portion 2, and the outer peripheral surface of the outer peripheral underground beam portion 2b are formed flush with each other.

  And in the slab part 2, the dimension D1 from the lower surface of the intermediate part 4 which is a part located inside the outer periphery underground beam part 2b in the bottom board part 2a to the lower end of the outer periphery underground beam part 2b is 0.3 m or more. is there. Here, the “dimension from the lower surface of the intermediate portion to the lower end of the outer peripheral underground beam portion” means the distance between the lower surface in the normal direction of the lower surface of the intermediate portion 4 and the lower end of the outer peripheral underground beam portion 2b. To do. Moreover, the outer periphery underground beam part 2b and the intermediate | middle part 4 located inside the outer periphery underground beam part 2b in the bottom board part 2a form the downward recessed part 15 opened below. The bottom surface (upper surface) of the downward concave portion 15 is constituted by an inner peripheral surface of the outer peripheral underground beam portion 2b and a lower surface of an intermediate portion of the bottom plate portion 2a. And the dimension from the lower surface of the intermediate part 4 of the bottom board part 2a to the lower end of an outer periphery underground beam part is equivalent to the depth of this downward recessed part 15. FIG.

  Moreover, the penetration depth D2 which is a dimension from the design ground line GL to the lower end of the outer periphery underground beam part 2b is 0.4 m or more. The grounds for limiting the numerical values of D1 and D2 will be described in [Principle of the present invention] described later. The upper limit of D1 is preferably 1.0 m or less, and the upper limit of D2 is preferably 1.1 m or less. Since surplus water is not expected to rise beyond 1.0 m from the crushed stone industry, even if D1 is 1.0 m or less and D2 is 1.1 m or less, the sand / This is because it can be absorbed by the gravel layer.

[How to create a solid foundation]
FIG. 2 is a partial cross-sectional view showing a method for building a solid foundation for a house using the solid foundation 1 for a house shown in FIG.

  Referring to FIG. 2, in the method for building the solid foundation of the house according to the first embodiment, the crushed stone industry 11 is created in the planned construction site of the house, and then on the portion excluding the outer peripheral part of the crushed stone industry 11. A sand / gravel layer 12 composed of at least one of sand and gravel is formed, and then the lower end of the outer peripheral beam portion 2b is positioned on the outer peripheral portion of the crushed stone industry 11, and the sand / gravel A solid foundation 1 is provided on the layer 12 so that the intermediate part 4 of the bottom part 2a is located. In addition, as above-mentioned, when the outer periphery underground beam part 2b is formed in the trapezoid whose one bottom angle is a right angle toward the downward direction, the solid foundation 1 is on the outer peripheral part of the crushed stone industry 11 It is provided so that the lower end surface of the outer peripheral underground beam portion 2b is positioned and the inner peripheral surface of the outer peripheral underground beam portion 2b and the lower surface of the intermediate portion 4 of the bottom plate portion 2a are positioned on the sand / gravel layer 12. . The sand / gravel layer 12 is flat so as to have an upper surface that conforms to the shape of the inner peripheral surface of the outer peripheral underground beam portion 2b constituting the bottom surface (upper surface) of the downward concave portion 15 and the lower surface of the intermediate portion 4 of the bottom plate portion 2a. It is constructed so as to have a trapezoidal longitudinal section.

  A leveling mortar layer (abandoned concrete layer) may be provided on the sand / gravel layer 12. A vinyl sheet for water shielding (moisture prevention) may be provided on the sand / gravel layer 12.

  And thickness D3 of the sand and gravel layer 12 under the intermediate part 4 of the bottom board part 2a shall be 0.3 m or more. Here, the “sand / gravel layer” may be composed of sand, gravel, or sand and gravel. The phrase “consisting of at least one of sand and gravel” means that “sand / gravel layer” substantially includes at least one of sand and gravel, and “sand / gravel layer” is a mixture of technical common sense. It may contain things. The grounds for limiting the numerical value of the thickness D3 of the sand / gravel layer below the intermediate portion 4 of the bottom plate 2a will be described in [Principle of the present invention] described later. In addition, it is preferable that thickness D3 of the said sand and gravel layer shall be 1.0 m or less. This is because surplus water is not expected to rise beyond 1.0 m from the crushed stone industry, so even if D3 is 1.0 m or less, it can be safely absorbed by the sand / gravel layer in the downward recess. .

[Function and effect]
1 and 2, according to the first embodiment, the solid foundation 1 includes an outer peripheral underground beam portion 2b and an intermediate portion 4 located on the inner side of the outer peripheral underground beam portion 2b in the bottom plate portion 2a. A downward concave portion 15 that opens downward is formed. A dimension D1 from the lower surface of the intermediate portion 4 of the bottom plate portion 2a to the lower end of the outer peripheral underground beam portion 2b corresponds to the depth of the downward recess 15. Then, as described above, the crushed stone industry 11 is formed on the planned construction site of the house, and the sand / gravel layer 12 is formed on the portion other than the outer peripheral portion of the crushed stone industry 11, and the crushed stone industry 11 When the solid foundation 1 is provided so that the lower end portion of the outer peripheral underground beam portion 2b is positioned on the outer peripheral portion and the downward concave portion 15 is positioned on the sand / gravel layer 12, the depth of the downward concave portion 15 is increased. Since it is 0.3 m or more, the downward concave portion can be filled with a sand / gravel layer having a thickness of 0.3 m or more. As a result, even if the ground is liquefied, surplus water rising to the downward recess 15 can be absorbed by the sand / gravel layer 12 in the downward recess 15, so that the sinking of the house can be prevented.

[Principle of the present invention]
<Calculation of sand layer thickness>
In the following, a safety calculation for liquefaction of the ground is performed using a building model in which the foundation of the building has a rectangular shape of 9.0 m × 7.0 m and a corner of 2 m × 2 m.

  First, specific gravities of gravel and sand alone, and gravel and sand containing water were determined by experiments.

  The specific gravity of only gravel is ρg1 = 1.42, and the specific gravity of (gravel + water) is ρg2 = 1.95.

  The specific gravity of only sand is ρs1 = 1.49, and the specific gravity of (sand + water) is ρs2 = 1.92.

  Next, the thickness of surplus water absorbed just below the building will be examined.

The difference between the specific gravity of gravel or sand containing water and the specific gravity of gravel or single sand is nothing but the specific gravity of the contained water, that is, the water content. Further, the moisture content in this specific gravity experiment corresponds to the water absorption rate. Therefore,
The water absorption rate of gravel is ρg2−ρg1 = 0.53,
The water absorption rate of sand is ρs2−ρs1 = 0.43.

  Here, since safety against liquefaction is calculated, the lower value 0.43 on the safe side is adopted as the water absorption rate.

  Excess pore water (surplus water) is generated in the liquefied layer below the normal water level due to the earthquake in sandy soil. Therefore, if the surplus water that rises can be safely absorbed and retained, it is possible to prevent the sinking and sinking of the building that occurs on the ground surface during an earthquake.

  As mentioned above, as the safety factor for the conclusion of the national paper, the safety factor of the allowable stress level specified in the notification of the Ministry of Land, Infrastructure and Transport 4). The notice stipulates that “the allowable stress level is 1/3 of the ultimate stress level”, and the safety factor is expected to be three times as high as the allowable stress level.

Here, the subsidence amount of the sand layer including the silt seam (low permeability layer) in the national paper was 3.7 cm. If we expect a safety factor of 3 times,
0.037 m × 3 = 0.111 m.

  The required sand layer thickness is proportional to the inverse ratio of its water absorption. Then, the necessary thickness of the sand layer is 0.111 ÷ 0.43 = 0.258 m.

<Application to buildings>
Next, application to the building model will be discussed with reference to FIGS. In the building model, the area of the solid foundation is (9 × 7) − (2 × 2) = 63−4 = 59 m ² . This is the liquefaction generation floor area.

  On the other hand, in this Embodiment 1, since the generated surplus water is absorbed by the sand / gravel layer 12 in the downward recess 15 described above, the area of the lower end surface of the outer peripheral underground beam portion 2b is reduced from the area of the solid foundation 1. What is subtracted is the substantial absorption floor area that substantially absorbs excess water.

The width of the lower end of the outer peripheral underground beam portion 2b is 0.25 m in the building model. Therefore, the area of the lower end of the outer peripheral underground beam portion 2b is (9 + 7) × 2 × 0.25 = 8 m ² . Therefore, the substantial absorption area is 59−8 = 51 m ² .

  The thickness of excess water generated is equal to the amount of ground subsidence. Therefore, the thickness of the surplus water is 0.111 m, which is calculated by considering the safety factor of the above three times to the subsidence amount of 3.7 cm in the national paper.

Then, the maximum generation amount of excess water becomes 0.111m × ^{59m 3} = 6,549m 3.

  The necessary sand layer thickness is 6,549 ÷ 51 ÷ 0.43 = 0.298≈0.30 m.

  In the case of a gravel layer, the required thickness is 6,549 ÷ 51 ÷ 0.53 = 0.242 m <0.298 m, which indicates that gravel is safer than sand.

In the building model, the dimension from the design ground line GL to the lower surface of the intermediate part 4 of the bottom panel 2a is 0.10 m. Therefore, the penetration depth of the solid foundation 1 on the outer periphery of the building is
0.30 + 0.10 = 0.40 m.

  Therefore, when the dimension D1 from the lower surface of the intermediate portion 4 to the lower end of the outer peripheral underground beam portion 2b is 0.3 m or more and the penetration depth D2 is 0.4 m or more, the gap generated at the time of the earthquake The sinking and sinking of the building due to the ejection of water (surplus water) can be prevented.

(Embodiment 2)
FIG. 3 is a diagram illustrating a configuration of the solid foundation 1 of the house according to the second embodiment of the present invention, the upper diagram is a plan view, and the lower diagram is a partial cross-sectional view of a portion B of the upper diagram. . This partial sectional view shows a longitudinal section along the horizontal direction of the solid foundation 1 in the B part.

Referring to FIG. 3, in the second embodiment, a pipe 13 having a predetermined number of ends or more opened per predetermined area over the entire surface of the bottom plate portion 2 a is vertically moved on the bottom plate portion 2 a. It is provided so that it may penetrate. Other points are the same as in the first embodiment. Although the material of the pipe 13 is not specifically limited, For example, it is a product made from vinyl. Here, the outer diameter of the pipe 13 is 0.075 m. For example, one or more pipes 13 are disposed per 5 m ² on the entire surface of the bottom board 2a. Here, for example, the area of the bottom plate portion 2a is (9 × 7) − (3 × 3) = 54 m ² , and 54 ÷ 5 = 10.8≈11 or more pipes 13 are disposed. Specifically, as shown in FIG. 3, thirteen are arranged on the entire surface of the bottom board 2a so as to be as uniform as possible. Moreover, since the density of the pipes 13 is important, the pipes 13 may be arranged randomly. However, it is preferable to arrange the pipes 13 in an aligned manner from the viewpoint of arranging the pipes 13 uniformly.

  In addition, when the leveling mortar layer (disposal concrete layer) or the vinyl sheet for water shielding is provided on the sand / gravel layer 12, the pipe 13 is composed of the mortar layer (disposal concrete layer) or the vinyl sheet for water shielding. It penetrates and is provided so that the lower end may open to the sand / gravel layer 12.

  According to the second embodiment, when the excess water generated by liquefaction rises in the sand / gravel layer 12 of the downward recess 15 of the bottom plate portion 2a, the air in the sand / gravel layer 12 of the downward recess 15 is opened at both ends. Since it is discharged | emitted from the made pipe 13, the said sand and gravel layer 12 can absorb an excess water easily. As a result, the sinking of the house can be suitably prevented.

(Embodiment 3)
FIG. 4 is a diagram showing a configuration of a solid foundation 1 for a house according to Embodiment 3 of the present invention, in which the upper diagram is a plan view, and the lower diagram is a partial cross-sectional view of part C of the upper diagram. . This partial sectional view shows a longitudinal section along the horizontal direction of the solid foundation 1 in the portion C.

  Referring to FIG. 4, in the third embodiment, the bottom plate portion 2 a has an outer periphery having a shape having an entrance corner 21. And the outer peripheral rising part 3a is provided in the outer peripheral part of the base part 2a over the perimeter of the said base part 2a. Further, an intermediate rising portion 3b is provided so as to connect to the outer peripheral rising portion 3a located at the corner 21 of the bottom plate portion 2a.

  According to the third embodiment, since the building having the corner is fixed on the outer peripheral rising portion 3a having the outer corner shape having the corner 21, the corner rising portion located at the corner of the corner 21 at the time of an earthquake. 16 generates a twisting moment. However, since the intermediate rising portion 3b supports the corner rising portion 16, it is possible to prevent the corner rising portion 16 from being damaged by the twisting moment.

(Embodiment 4)
FIG. 5 is a diagram illustrating a configuration of a solid foundation 1 for a house according to a fourth embodiment of the present invention, a lower diagram is a plan view, and an upper diagram is a partial cross-sectional view of a portion D in the lower diagram. . This partial sectional view shows a longitudinal section along the horizontal direction of the solid foundation 1 in the portion D.

  Referring to FIG. 5, in the fourth embodiment, the bottom plate portion 2 a has an outer periphery having a shape having a protruding corner 22. Then, the outer peripheral rising portion 3a has an outer periphery in a shape having an entry corner 21 along the outer periphery of the bottom plate portion 2a excluding the protruding corner 22 portion in plan view, and the bottom plate portion 2a. It is provided to stand up from.

  According to the fourth embodiment, since the building having the corner is fixed on the outer peripheral rising portion 3a having the outer corner 21 having the corner 21, a twisting moment is generated in the corner rising portion 16 at the time of an earthquake. However, since the outer peripheral underground beam portion 2b of the exit corner 22 supports the entrance corner rising portion 16, it is possible to prevent the entrance corner rising portion 16 from being damaged by the twisting moment.

  From the foregoing description, many modifications and other embodiments of the present invention are obvious to one skilled in the art. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention.

  The solid foundation of a house and its creation method of the present invention are useful as a solid foundation of a house that can prevent the sinking and sinking of the house when the ground is liquefied and its creation method.

DESCRIPTION OF SYMBOLS 1 Solid foundation 2 Slab part 2a Bottom board part 2b Outer peripheral underground beam part 3a Outer peripheral rising part 3b Intermediate rising part 4 Intermediate part 11 Crushed stone industry 12 Sand and gravel layer 13 Pipe 15 Downward recessed part 16 In corner rising part 21 In corner 22 Out Corner D1 Dimension D2 Dimension D3 Thickness GL Ground line

In order to solve the above-mentioned problem, a solid foundation according to an aspect of the present invention is a solid foundation of a house having an entrance, a kitchen, a bath, a toilet, and a living room, and rises from the slab portion and the slab portion. A slab portion having a predetermined shape outer periphery, extending from a plate-shaped bottom plate portion extending along a design ground line, and an outer peripheral portion of the bottom plate portion, to the entire periphery of the outer peripheral portion. The outer underground beam portion protruding downward, and from the lower surface of the intermediate portion that is a portion located inside the outer peripheral underground beam portion in the bottom plate portion to the lower end of the outer circumferential underground beam portion dimensions, der least 0.3m is, the bottom plate portion, over the entire surface of the bottom plate portion, the pipe a predetermined number or more ends per given area has been opened, passing through the bottom plate portion in the vertical direction The opening at the upper end of the pipe is Unblocked by the member.

According to this structure, the outer periphery underground beam part of a solid foundation and the intermediate part located inside the outer periphery underground beam part in a bottom board part form the recessed part (henceforth downward recessed part) opened below. And the dimension from the lower surface of the intermediate part of a bottom board part to the lower end of an outer periphery underground beam part is equivalent to the depth of this downward recessed part. Then, a crushed stone industry was created in the planned construction site of the house, a sand and gravel layer was formed on the portion other than the outer periphery of the crushed stone industry, and an outer ground underground beam was formed on the outer periphery of the crushed stone industry. When the solid foundation is provided so that the lower end portion of the portion is located and the downward concave portion is positioned on the sand / gravel layer, the depth of the downward concave portion is 0.3 m or more. It can be filled with sand and gravel layers with a thickness of 3m or more. As a result, even if the ground is liquefied, surplus water rising in the downward recess can be absorbed by the sand / gravel layer in the downward recess, so that the sinking of the house can be prevented. In addition, when excess water generated by liquefaction rises in the sand / gravel layer in the downward recess of the bottom plate, the air in the sand / gravel layer in the downward recess is discharged from the pipe open at both ends.・ The gravel layer can absorb excess water easily. As a result, the sinking of the house can be suitably prevented.

In order to solve the above-mentioned problems, a solid foundation according to an aspect of the present invention ( except when a discarded concrete layer is provided over the entire lower surface) includes a front door, a kitchen, a bath, a toilet, and a living room. A plate-shaped bottom board having a predetermined outer periphery and extending along a design ground line, comprising a slab part and a rising part rising from the slab part And an outer peripheral underground beam portion projecting downward from the outer peripheral portion of the bottom plate portion over the entire circumference of the outer peripheral portion, and located inside the outer peripheral underground beam portion in the bottom plate portion The dimension from the lower surface of the intermediate portion, which is a portion, to the lower end of the outer peripheral underground beam portion is 0.3 m or more, and the bottom plate portion has a predetermined number or more per predetermined area over the entire surface of the bottom plate portion. pipe whose both ends are open (termite particles of filler And excluding water drainage holes), the bottom plate portion provided so as to penetrate in the vertical direction, the opening at the upper end of the pipe is not closed by the other members.

Claims (6)

A solid foundation for a house with a front door, kitchen, bath, toilet, and living room,
A slab part and a rising part rising from the slab part,
The slab portion has an outer periphery of a predetermined shape, and protrudes downward from the outer peripheral portion of the plate-like bottom plate portion extending along the design ground line and the outer peripheral portion of the bottom plate portion over the entire circumference of the outer peripheral portion. Including an outer periphery underground beam portion,
A solid foundation for a house, wherein a dimension from a lower surface of an intermediate portion, which is a portion located inside the outer peripheral underground beam portion in the bottom plate portion, to a lower end of the outer peripheral underground beam portion is 0.3 m or more.   The solid foundation of a house according to claim 1, wherein a penetration depth, which is a dimension from the design ground line to a lower end of the outer peripheral underground beam portion, is 0.4 m or more.   A pipe having a predetermined number or more of open ends per predetermined area is provided in the bottom plate portion so as to penetrate the bottom plate portion in the vertical direction over the entire surface of the bottom plate portion. Solid foundation for housing as described in 2.   The bottom plate portion has an outer periphery with a corner shape, and an outer periphery rising portion is provided on the outer periphery of the bottom plate portion over the entire periphery of the bottom plate portion, and the outer periphery is located at the corner of the bottom plate portion. The solid foundation of the house according to any one of claims 1 to 3, wherein an intermediate rising portion is provided so as to be connected to the rising portion.   The bottom board portion has an outer periphery with a shape having a protruding corner, and the rising portion has an outer corner along the outer periphery of the bottom plate portion except for the protruding corner portion in a plan view, and has an entering corner at the protruding corner portion. The solid foundation of a house according to any one of claims 1 to 3, further comprising an outer peripheral rising portion having an outer periphery having a shape and rising from the bottom plate portion. A method for building a solid foundation for a house using the solid foundation for a house according to any one of claims 1 to 5,
Creating a crushed stone industry in the planned construction site of the house;
Creating a sand / gravel layer composed of at least one of sand and gravel on a portion excluding the outer peripheral portion of the crushed stone industry;
The step of providing the solid foundation so that the lower end portion of the outer peripheral underground beam portion is positioned on the outer peripheral portion of the crushed stone industry and the middle portion of the bottom plate portion is positioned on the sand / gravel layer. And including
A method for constructing a solid foundation for a house, wherein a thickness of the sand / gravel layer under the intermediate part of the bottom board is 0.3 m or more.

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