JP3065228B2 - How to build a building foundation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a building foundation for constructing a building on soft ground.

[0002]

2. Description of the Related Art When constructing a building on soft ground, in order to support the weight of the building, a solidified material is injected into the ground, and a foundation pile reaching a solid support layer is formed. Had improved. In addition, excavating the ground to build the foundation of the building required a retaining wall that could withstand the earth pressure and water pressure acting on the excavated surface.

[0003] Therefore, in the construction of such a conventional building foundation, it is necessary to install a large-scale and solid retaining wall as a temporary material together with the improvement of the ground, which is a considerable burden.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems. The purpose is to improve the ground by injecting the solidified material into the soft ground and use the discharged slime effectively by injecting the solidified material when constructing the building foundation, function as a retaining wall, and make a large temporary temporary It is an object of the present invention to propose a method of constructing a building foundation that can eliminate the need for construction, and at the same time can save labor and cost.

[0005]

According to the method of constructing a building foundation, in a method of constructing a building foundation in which a solidified material is injected into soft ground to improve the ground, and a building is constructed thereon, slime discharged at the time of ground improvement is used. It is characterized by being buried around the base part to form a slime compact.

[0006]

The present invention has the above-mentioned structure, and backfills the discharged slime. The slime consolidated body formed around the building foundation opposes the surrounding earth pressure and acts on the excavated surface of the building foundation. Can be reduced. Accordingly, construction work such as excavation can be performed without installing a girder or installing a large retaining wall.

Further, since the slime is effectively used at the site where the slime is generated, the disposal cost is reduced and the environment is effectively protected.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of constructing a building foundation will be described below in the order of steps with reference to the drawings.

[0009] A mountain retaining wall 2 is provided around the building on the soft ground 1 on which the building is to be constructed (see FIG. 1).

Excavation is performed on the outside of the retaining wall 2, that is, around the building to be constructed while forming a slope with a stable slope angle according to the soil quality (see FIG. 2). At this time, if the groundwater level is high, a well point 3 is provided on the slope to lower the groundwater level, and excavation proceeds.

After excavation to a predetermined depth, in order to reduce deformation and stress of the retaining wall, a cutting beam 4 receiving earth pressure is erected on a line diagonally connecting the top of the retaining wall 2 and the root bottom. . In addition, a belly material 5 for increasing the rigidity of the retaining wall 2 in the out-of-plane direction is attached between the adjacent cutting beams 4. Excavate the remaining soil near the mountain retaining wall 2.

Next, as shown in FIG. 3, a solidification material is injected by a jet-type stirring method over the entire lower surface of the building to be constructed, mixed with the soil and soil, and a ground improvement body 6 is formed. The slime 7 in the form of a slurry made of a mixture of the earth and sand and the solidified material discharged during the ground improvement is buried in the excavation space around the excavated building.

Thereafter, as shown in FIG. 4, backfilling of the slime 7 to be discharged is continued, and the well point 3 is removed when the upper surface position of the slime 7 becomes higher than the groundwater level. Stop and allow to solidify.

After the backfilled slime 7 solidifies to form a slime consolidated body 8 and reaches a predetermined strength, a solidified material is injected from the ground as shown in FIG. The ground improvement part 9 having a predetermined width reaching the depth below the root cut is created.

After the strength of the ground improvement part 9 below the slime consolidated body 8 has developed, as shown in FIG. 6, excavation of the building foundation, that is, the inside of the retaining wall 2 is started.

Excavation is continued, and as shown in FIG. 7, excavation is performed up to the root bottom reaching the ground improvement body 6 to construct a building foundation. FIG.
Is a building 10 built on the building foundation. The foundation of the building is ground improvement body 6, slime consolidated body 8, and ground improvement section 9.
And the groundwater is prevented from entering.

In the above embodiment, the ground improvement part 9 is provided below the slime consolidated body 8, but it is not always necessary to provide the ground improvement part 9.
However, when the ground improvement part 9 is provided as in the embodiment, the slime solidified body 8 and the ground improvement part 9 are united even when the excavation proceeds, and the earth pressure is balanced with the earth pressure, and the earth pressure is applied to the retaining wall. It does not work, and construction can proceed as it is.

[0018]

The present invention is as described above. A solidified material is injected into soft ground, a ground improvement body is formed, and slime discharged with the ground improvement when a building is constructed thereon is backfilled. By making a slime compact around the building,
Extensive temporary stakes are not required, and excavation of the ground of a building foundation, efficiency of foundation construction, and reduction of construction costs can be achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a state where a retaining wall is installed underground.

FIG. 2 is a cross-sectional view of a state where an outer peripheral portion of a retaining wall is excavated.

FIG. 3 is a cross-sectional view showing a state where a solidification material is injected into the inside of the retaining wall to form a ground improvement body.

FIG. 4 is a cross-sectional view showing a state in which the discharged slime is backfilled to the outer peripheral portion of the retaining wall to form a slime compact.

FIG. 5 is a cross-sectional view showing a state in which a ground improvement part is formed below the slime compact.

FIG. 6 is a cross-sectional view of a state where a building base portion inside a retaining wall is excavated.

FIG. 7 is a sectional view of a building foundation portion excavated to a root incision.

FIG. 8 is a conceptual diagram of a state in which a building has been built on an excavated building base.

[Explanation of symbols]

1 ... soft ground, 2 ... earth retaining wall, 3 ... well point, 4 ... cut beam, 5 ... belly material, 6 ... ground improvement body, 7
… Slime, 8… slime solidification, 9… ground improvement section, 10… building.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masayoshi Nagata 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Inventor Hiroaki Kubo 3-164 Nakamura Minami, Nerima-ku, Tokyo (56) References JP-A-63-233115 (JP, A) JP-A-53-87511 (JP, A) JP-A-5-287722 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) E02D 3/00 E02D 3/12 E02D 27/00-27/52 E02D 17/04

Claims (1)

(57) [Claims] 1. A method of constructing a building foundation in which a solidified material is injected into soft ground to improve the ground, and a building is constructed thereon, wherein slime discharged at the time of ground improvement is backfilled around the building foundation. A method for constructing a building foundation, comprising forming a slime compact.