JPH09296437A - Construction method of foundation ground of building - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To provide a construction method for a foundation ground of a building, which enables extremely efficient, economical and safe ground improvement of soft ground. SOLUTION: An excavation space 4 is constructed in a soft ground 1 on which a building 12 is constructed, a solidifying material is injected into the soft ground 1, and the mixture is agitated and mixed to form a ground improvement body 6, which is the ground improvement body. A solidifying material is added to the slime discharged when building 6, and the mixture is stirred and mixed, and this slime is backfilled in the excavation space 4 to form a ground improvement body 7 continuous with the ground improvement body 6. . Moreover, the earth retaining walls 2 and 3 are constructed in the soft ground 1 to divide the soft ground 1 into a plurality of sections.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art When building a building on soft ground,
In order to support the weight of the building, it is necessary to improve the soft ground to a solid and stable ground.Conventionally, this type of ground improvement method has been to inject a solidifying material such as cement paste into the soft ground and It is generally known to form a foundation ground that reaches a solid support layer by stirring and mixing with.

[0003]

However, in this type of ground improvement, a large amount of slime in the form of a slurry formed of a mixture of earth and sand and a solidifying material is generated, and this slime needs to be treated with mud. However, there were problems such as a great burden in terms of labor and cost for this mud treatment. In addition, the mud treated cannot be expected to have sufficient strength to support a building, and thus is treated as industrial waste, which has been a considerable burden. Furthermore, in order to excavate soft ground and construct the foundation part of the building, it is necessary to improve the ground and also to construct the earth retaining wall that withstands the earth pressure and water pressure acting on the excavation surface particularly firmly. There were problems such as requiring a great deal of labor and expense.

The present invention has been made to solve the above problems, and provides a method for constructing a foundation ground of a building which enables extremely efficient, economical and safe ground improvement of soft ground. The purpose is to do.

[0005]

A method for constructing a foundation ground of a building according to the present invention is to construct an excavation space in a soft ground where a building is constructed, inject a solidifying material into the soft ground, and mix with stirring. By forming a ground improvement body by doing, by mixing with stirring while adding a solidifying material to the slime discharged when creating the ground improvement body, and the ground improvement body by backfilling this slime in the excavation space Create an integrated ground improvement body. Further, a mountain retaining wall is constructed in the soft ground to divide the soft ground into a plurality of sections.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment of the Invention 1 (a), (b), (c), (d), and (e) show an embodiment of the present invention, which will be described in order below.

First, the soft ground 1 on which the building is constructed
Inside, the mountain stopper walls 2 and 3 are arranged appropriately, for example, in the shape of a simple rectangle or grid, or in the shape of a cross girder, and the soft ground 1
Are divided into appropriate areas and shapes. In this case, the mountain retaining wall 2 divides the soft ground 1 into an appropriate area and shape to prevent the ground from moving or collapsing when the ground is improved, thus ensuring work safety and facilitating ground improvement work. In addition, it is constructed to improve the stability of the ground after ground improvement, for example, PC sheet piles or sheet piles (see Figure (a)).

Next, the excavation space 4 is formed by excavating the ground of this portion outside the cliff wall 2 while forming a slope having a stable slope angle according to the soil quality (see FIG. (A)). ).

The excavation space 4 is dug down to the bottom of the portion where the ground is to be improved. Also, in this case, if the groundwater level is high, a well point (not shown) will be provided on the slope to reduce the groundwater level and proceed with excavation as necessary to ensure construction safety.

Next, when the excavation space 4 can be excavated to a predetermined depth, the landscaping wall 2 is provided with a plurality of tieback anchors 5 and the like inside the landslide wall 2 in preparation for deformation and stress of the landslide wall 2. Support in the ground.

Next, the soft ground 1 inside the mountain retaining wall 2
Inside, by injection type stirring method, that is, while injecting a solidifying material such as cement paste into the soft ground 1,
Ground improvement body 6 by thoroughly stirring and mixing the solidifying material and ground soil
(See Figure (b)). At the same time, after adding the solidifying material to the slime in the form of a slurry made of a mixture of the earth and sand and the solidifying material discharged to the ground at the time of creating the ground improvement body 6, and thoroughly stirring and mixing the slime, the slime is excavated in the space. It is backfilled with 4 and the ground improvement body 7 is created (refer to figure (b)). In this case, the solidifying material to be added to the slime is added by examining the compounding amount so that the supporting strength of the ground improving body 7 becomes equal to that of the ground improving body 6.

Next, the soft ground 1 between the mountain retaining walls 2 and 3 is dug down to construct an excavation space 8. In this case, the soft ground 1a above the ground improvement body 6 is exposed until the ground improvement body 6 is exposed. Excavate and excavate the soft ground 1b around the ground improvement body 6 to the bottom portion of the ground improvement body 6 (see FIG. (C)). Further, when the excavation space 8 can be excavated to a predetermined depth, the mountain retaining wall 3 is placed in the ground outside the mountain retaining wall 3 with a plurality of tieback anchors 5 or the like in preparation for deformation and stress of the mountain retaining wall 3. To support.

Next, the soft ground 1 outside the mountain retaining wall 3
Inside, the ground improvement body 9 is formed by the injection stirring method as in the case of. At the same time, a solidifying material is further added to the slime discharged above the ground when the ground improvement body 9 is formed, and the mixture is sufficiently stirred and mixed, and then the slime is backfilled to the level of the ground improvement body 7 in the excavation space 8. The ground improvement body 10 integrated with the ground improvement bodies 6 and 7 is formed (see FIG. (D)).

Next, excavating the soft ground 1c on the ground improvement body 9 until the ground improvement body 9 is exposed, and removing the projecting portions 2a and 3a of the mountain retaining walls 2 and 3 by removing it. As a result, the ground improvement bodies 6, 7, 9 are made continuous to form the stable ground 11, and the building 12 is constructed on the stable ground 11 (see Fig. (E)).

When the excavation spaces 4 and 8 are excavated, the amount of slime discharged to the ground when constructing the ground improvement body is examined, and an appropriate size and depth that can process the discharged slime without excess or deficiency. Shall be built.

Further, regarding the construction position of the ground improvement body and the construction position of the excavation space in which the slime discharged during the formation of the ground improvement body is filled up, the intervals and the like should be carefully examined so that the work can be performed most efficiently. To decide.

Embodiment 2 of the Invention 2 (a), (b), (c),
(d) and (e) show another embodiment of the present invention. In the steps of the ground improvement method shown in the first embodiment of the present invention, particularly different steps will be described. The shallow excavation space 4 is constructed (see Figure (a)). Then, the ground improvement body 6 is formed in the soft ground 1 inside the mountain retaining wall 2 by the injection stirring method. At the same time, a solidifying material is further added to the slime discharged to the ground when the ground improvement body 6 is constructed, and after sufficiently stirring and mixing, the slime is backfilled in the excavation space 4 to form the ground improvement body 7 ( (See Figure (b)). In this case, the ground improvement body 7 is constructed below the upper end surface of the ground improvement body 6 and shallower than the ground improvement body 6 (a depth of 1/2 or less of the ground improvement body 6).

Next, the soft ground 1 between the mountain retaining walls 2 and 3 is dug down to the upper end surface of the ground improvement body 7 (see FIG. (C)).
In this case, excavate the soft ground 1a above the ground improvement body 6 until the ground improvement body 6 is exposed, and also drill the soft ground 1b around the ground improvement body 6 to the bottom portion of the ground improvement body 6. The excavation space 8 is constructed around the ground improvement body 6. Further, by removing the protruding portion 2a of the mountain retaining wall 2, the ground improvement bodies 6 and 7 are made into one continuous ground improvement body (see FIG. (D)).

Next, the ground improvement body 13 is formed in the soft ground 1d below the ground improvement body 7 by the injection stirring method. At the same time, a solidifying material is further added to the slime discharged to the ground when the ground improvement body 13 is formed, and after sufficiently stirring and mixing, the slime is backfilled in the excavation space 8 to be continuous with the ground improvement bodies 6 and 7. Stable soil 11 consisting of soil improvement bodies 6, 7, 13, 14 by creating a soil improvement body 14
Then, the building 12 is built on the stable ground 11.
The other steps are almost the same as those in the first embodiment of the invention.

[0020]

The method for constructing the foundation ground of a building according to the present invention has the above-described structure, constructs an excavation space in the soft ground where the building is constructed, and injects a solidifying material into the soft ground. Agitating and mixing to create a ground improvement body, adding a solidifying material to the slime discharged during the creation of the ground improvement body, and mixing with stirring, and then backfilling the slime into the excavation space to improve the ground. Since a ground improvement body that is continuous with the body is newly created, the solidification material is added to the slime discharged during the creation of the ground improvement body, and the mixture is stirred and mixed, and then it is backfilled into the excavation space and newly created. Since the soil improvement body is created, it is not necessary to treat the slime mud, and this mud is used as backfill soil without being discarded, so it is extremely economical and efficient to improve the soil. It can be carried out.

In addition, since the earth retaining wall is constructed in the soft ground to divide the soft ground into a plurality of pieces during the ground improvement, the ground movement or collapse during the ground improvement can be prevented, and the construction safety can be improved. The ground improvement work is easy, and the ground stability after ground improvement is improved.

[Brief description of drawings]

1 (a), (b), (c), (d) and (e) are vertical cross-sectional views showing an embodiment of the present invention and showing steps of a ground improvement method.

2 (a), (b), (c), (d) and (e) are vertical cross-sectional views showing another embodiment of the present invention and showing steps of the ground improvement method.

[Explanation of symbols]

1 ... Soft ground, 2, 3 ... Mountain retaining wall, 4 ... Excavation space, 5 ... Tieback anchor, 6,7 ... Ground improvement body, 8 ... Excavation space,
9,10… Soil improvement body, 11… Stable ground, 12… Building, 13,14
… Ground improvement body.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadashi Takeuchi 1-3-8 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. Tokyo Branch (72) Inventor Tatsuaki Ichimura 1-chome, Moto Akasaka, Minato-ku, Tokyo No. 3-8 Kashima Construction Co., Ltd. Tokyo Branch (72) Inventor Yukio Mohri Kamo Construction Co., Ltd. Tokyo Branch (72) Inventor Susumu Uesawa Tokyo Metropolitan Port City Akasaka 1-6-4 Chemikarugrout Co., Ltd.

Claims (2)

[Claims] 1. A method for constructing a foundation ground of a building in which a solidified material is poured into soft ground and mixed by stirring to form a ground improved body, and a building is constructed on the ground improved body. While constructing the excavation space in, the solidification material is added to the slime discharged when constructing the soil improvement body and mixed by stirring, and the slime is backfilled in the excavation space and integrated with the soil improvement body. Construction method of foundation ground of building characterized by constructing ground improvement body. 2. The method for constructing a foundation ground of a building according to claim 1, wherein a mountain retaining wall is constructed in the soft ground to divide the soft ground into a plurality of sections.