JP2001348886A - Building foundation construction method in weak ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the uneven settlement of concrete placed on the ground surface of the soft ground so as not to interfere with the use of a building and the ground surface. SOLUTION: A foundation pile 3 is driven into the hard ground 2 in a lower layer from the soft ground 1 so that depth D from the ground surface 1a of the soft ground 1 to an upper face 4a of a footing 4 provided at the upper end 3a of the foundation pile is the predicted ground settlement or more. The footing 4 is provided at the upper end 3a of the foundation pile 3, and a column 5 is erected on the footing 4. The concrete 6 is placed on the ground surface 1a of the soft ground 1 excluding the upper part of the footing 4, and a buried space 7 above the footing 4 is filled with a removable embedded material 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a seashore, a sea, a river,
The present invention relates to a foundation method for building on soft ground when building a building on soft ground in which a swamp or the like has been reclaimed.

[0002]

2. Description of the Related Art Conventionally, when a building is built on soft ground (ground containing water) such as a landfill, first, as shown in FIG. 5, from a soft ground 1 to a lower hard ground (supporting ground) 2 as shown in FIG. A pile 3 is placed in the soft ground 1, a concrete footing 4 is provided on an upper end 3 a of the pile 3, and a pillar 5 is placed on the footing 4.
Is erected, and a concrete foundation 6 is cast to cover the soft ground 1 and the footing 4 exposed on the surface of the ground, thereby constructing the foundation of the building, and the building is constructed on this foundation.

[0003]

In such a case, FIG.
As shown in the figure, the soft ground 1 undergoes consolidation settlement over time.
For example, about 25 cm one year after completion, subsidence almost converges6
About 90 cm later. Then, concrete 6
The surface of the footing 4 where the surface does not sink in response to the consolidation settlement of the soft ground 1 and the part of the soft ground 1 which sinks form continuous irregularities, and a gap may be formed between the building and the ground surface. The ground surface becomes unusable. Therefore, when wavy irregularities occur on the ground surface, the wavy interstitial concrete 6 has to be removed and new interstitial concrete has to be poured.

[0004] The present invention has been developed in view of the above-mentioned points, and an object of the present invention is to prevent uneven settlement of concrete poured on the ground surface of soft ground, and to use the ground surface. It is an object of the present invention to provide a building foundation method on soft ground which does not cause troubles.

[0005]

SUMMARY OF THE INVENTION The present invention has the following configuration in order to effectively achieve the above object. That is, the building foundation in the soft ground according to the first aspect of the present invention is configured such that the depth from the ground surface of the soft ground to the upper surface of the footing provided at the upper end of the foundation pile is equal to or more than the ground subsidence expected in the future. A foundation pile is cast from the soft ground to a lower hard ground, a footing is provided at the upper end of the foundation pile, a pillar is erected on the footing, and the soft ground except above the footing is provided. The concrete structure is cast on the ground surface and the buried space above the footing is buried with a removable burying material.

According to a second aspect of the present invention, a depth of a soft ground from a ground surface of the soft ground to an upper surface of a footing provided at an upper end of a foundation pile is equal to or greater than a ground subsidence expected in the future. In this way, each foundation pile is cast from the soft ground to the lower hard ground with appropriate intervals, and a footing is provided at the upper end of each foundation pile, and an underground beam connecting each footing is provided, Pillars are erected on the desired footing, and concrete is cast on the ground surface of the soft ground except above each footing and each center beam, and further buried space above the footing and each center beam. This is a configuration characterized by filling with a removable embedding material.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same reference numerals are used for the same parts as described above for convenience.

FIG. 1 and FIG. 2 are explanatory views showing a foundation method for a building on soft ground according to the present invention. This method is based on, for example, the ground of a soft ground 1 reclaimed with earth and sand in a landfill such as the sea. The soft ground 1 is set so that the depth D from the surface 1a to the upper surface 4a of the footing 4 provided at the upper end 3a of the foundation pile 3 is equal to or greater than the amount of ground subsidence expected in the future.
From above, a foundation pile 3 is driven into the lower hard ground 2, and a footing 4 is provided on the upper end 3 a of the foundation pile 3.

On the footing 4, a pillar 5 of a building to be constructed is erected. Further, concrete 6 is cast and covered on the ground surface 1a of the soft ground 1 except for the buried space 7 above the footing 4, and the buried space 7 is a buried material that is slightly hardened so that sand, small blocks, etc. can be removed. Fill with 8. The surface 8a of the embedding material 8 is flush with the surface 6a of the concrete 6.

In the building foundation constructed in this manner, the soft ground 1 gradually consolidates and sinks as time passes, and the concrete 6 covering the ground surface 1a of the soft ground 1 also sinks with the settlement. However, since the concrete 6 is provided on the ground surface 1a of the soft ground 1 except for the area above the footing 4 as described above, the embedding material 8 that does not sink together with the soft ground 1 has an amount corresponding to the sinking of the soft ground 1 and the concrete 6. It is exposed above the surface 6a of the concrete 6. Therefore, the exposed embedded material 8 is removed with a scoop or the like, and the surface 6a of the sinking concrete 6 is removed.
And the shaved surface 8b of the embedded material 8 (see FIG. 2)
And the same.

As described above, since the concrete 6 covering the ground surface 1a of the soft ground 1 is not provided so as to overlap the footing 4 as in the prior art, the whole of the soft ground 1 sinks substantially uniformly as the soft ground 1 sinks. However, no wavy irregularities are formed.

FIGS. 3 and 4 are explanatory views of another example of the foundation method for building on soft ground according to the present invention. The foundation method for building on soft ground is similar to that of the above-described example. Each of the foundation piles 3 is appropriately spaced from each other so that the depth D from the ground surface 1a to the upper surface 4a of the footing 4 provided at the upper end 3a of the foundation pile 3 is equal to or greater than the amount of ground subsidence expected in the future. Driving from soft ground 1 to lower hard ground 2
A footing 4 is provided at the upper end 3a of each foundation pile 3. Underground beams 9 are provided and connected between the footings 4. A pillar 5 is erected on the desired footing 4,
A buried space 7 above each footing 4 and a central beam 9
Concrete 6 is cast on the ground surface 1 a of the soft ground 1 except for the surface 10. Further, the burying spaces 7 and 10 above the footing 4 and the central beam 9 are filled with the removable filling material 8 described above. The surface 8 a of the embedding material 8 embedded in each of the embedding spaces 7 and 10 is made to be flush with the surface 6 a of the concrete 6.

In this example, as described above, the soft ground 1 gradually consolidates and sinks as time passes.
With this settlement, the concrete 6 covering the ground surface 1a of the soft ground 1 also sinks. However, since the concrete 6 is cast on the ground surface 1a of the soft ground 1 excluding the footing 4 and the underground beam 9 as described above, the embedded material 8 that does not sink does not sink in the soft ground 1 and the concrete 6. It is exposed above the surface 6a of the concrete 6 by an amount. By removing the exposed embedding material 8, the surface 6 a of the sinking concrete 6 can be flush with the shaved surface (not shown) of the shaved embedding material 8.

Therefore, since the concrete 6 is not provided so as to overlap the footing 4 and the underground beam 9 as in the prior art, even if the soft ground 1 sinks, the whole of the concrete 6 descends substantially uniformly, and the wavy irregularities are formed. Does not occur.

[0015]

As is apparent from the above description, in the foundation method for building on soft ground according to the present invention, concrete poured on the ground surface of soft ground substantially sinks with consolidation of soft ground. By removing the embedding material on the footing and making the surface of the concrete and the surface of the embedding material flush, the ground surface, which is the concrete surface, can be kept flat, and the building constructed on this foundation And there is no hindrance to the use of the ground surface.

The same effect as described above can also be obtained in the foundation of a building in which footings provided in the ground are connected by underground beams by the method of building foundation on soft ground according to the present invention.

[0017]

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a state immediately after completion by a building foundation method on soft ground according to the present invention.

FIG. 2 is an explanatory diagram showing a state after a lapse of a predetermined period by a building foundation method on soft ground according to the present invention.

FIG. 3 is an explanatory diagram showing a state immediately after completion of another example of a building foundation method on soft ground according to the present invention.

FIG. 4 is an explanatory plan view of another example of the building foundation method on soft ground according to the present invention.

FIG. 5 is an explanatory diagram showing a state immediately after completion by a conventional building foundation method on soft ground.

FIG. 6 is an explanatory diagram showing a state after a lapse of a predetermined period by a conventional building foundation method on soft ground.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Soft ground 1a Ground surface 2 Hard ground 3 Foundation pile 3a Upper end 4 Footing 4a Upper surface D Depth 5 Column 6 Concrete 7 Embedded space 8 Embedded material 9 Underground beam 10 Embedded space

Claims (2)

[Claims] 1. A method of mounting a foundation pile from a soft ground to a lower hard ground so that a depth from a ground surface of the soft ground to an upper surface of a footing provided at an upper end of the foundation pile is equal to or greater than a ground subsidence expected in the future. And a footing is provided at the upper end of the foundation pile, a pillar is erected on the footing, and
A foundation method for a building on soft ground, wherein concrete is cast on the ground surface of the soft ground except above the footing, and the buried space above the footing is filled with a removable embedding material. 2. The method according to claim 1, wherein a depth from a ground surface of the soft ground to an upper surface of a footing provided at an upper end of the foundation pile is equal to or more than a land subsidence expected in the future. Driving from soft ground to lower hard ground, and providing a footing at the upper end of each foundation pile, and providing an underground beam connecting each footing, further erecting a column on the desired footing, and , Concrete is poured on the ground surface of the soft ground except for each footing and the upper part of the central beam,
Furthermore, a foundation method for building on soft ground, characterized by filling the footing and the buried space above the central beam with a removable buried material.