JPH0751769B2 - Ground improvement method for construction - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improved construction method for building ground.

(Prior Art) Conventionally, a method of improving the surface soil of the ground by using a cement-based solidifying material (referred to as Conventional Example 1), a method of reinforcing the ground by adding a reinforcing material (referred to as Conventional Example 2), a reinforcing material in the embankment There was a construction method (referred to as Conventional Example 3) in which the ground is put in to strengthen the ground.

(Problems to be Solved by the Invention) In Conventional Example 1, the compressive strength is increased, but the tensile strength is not, and there is a problem that, for example, when a vertical compressive force is applied to the ground, cracks easily form in the ground. It was

The conventional example 2 has a problem in that the soil is disturbed when the reinforcing material is inserted, and the compressive strength is weakened.

In the conventional example 3, since the reinforcing material is put in the embankment, there is a problem that the ground is insufficiently compacted.

(Means for Solving Problems) The present invention is to excavate the current ground over the entire construction site to remove the topsoil, and lay a new good sand on the base bottom of the ground from which the topsoil has been removed, The new earth and sand and an appropriate amount of solidifying material are mixed and stirred, and then compacted to form an underlayer, and a reinforcing material formed in a lattice shape, a mesh shape, or the like is arranged on the underlying board. A new soil of good quality is laid on top of this to a suitable thickness, and the new soil and an appropriate amount of solidifying material are mixed and stirred, and then compacted to form the upper ground and form the building ground. It is an improved construction method.

(Function) By arranging the reinforcing material between the base and the upper ground, which are improved by new quality sand and an appropriate amount of solidifying material, the compressive strength and shear strength of the ground as well as the tensile strength are increased.

(Example) Drawing shows the Example of the ground improvement method for construction of this invention.

First, the existing ground 1 in the entire building ground is excavated by using an excavator (not shown) or the like to remove the topsoil 2 having a depth of about 300 mm to 700 mm (see FIG. 2). The thickness of the topsoil 2 to be removed may be 200 mm in consideration of the softness of the topsoil 2, or 100
In some cases, about 0 mm is required.

In this way, an appropriate amount of new earth and sand 4 is laid on the base bottom 3 of the ground from which the top soil 2 has been removed. An appropriate amount of the solidifying material 5 is sprinkled on this new quality sand 4 and the solidifying material 5 and the new quality sand 4 are mixed and stirred using an excavator to obtain the first improved soil 6 Eggplant (see Figure 4).

As the new high quality earth and sand 4, it is preferable to use well-drained earth, sand, river sand, sea sand, Masa earth, etc. alone or in combination.

As the solidifying material 5, a ground stabilization agent, cement or the like is used alone or in a mixture. As the ground stabilization agent, for example, Fuji Beton (trade name of Keio Kaken Kogyo Co., Ltd.) or Asano Clean Set 1140 (trade name of Nippon Cement Co., Ltd.) is suitable.

The surface of the above-mentioned first improved soil 6 is leveled with, for example, a bucket of an excavator, and the first improved soil 6 is temporarily compressed.

After the temporary rolling pressure is completed, the level of the first improved soil 6 is measured, and the operator corrects a large level difference, a mixed unevenness, or the like.

After the correction of the level difference and the like, the first improved soil 6 is fully compacted by using a roller or the like (not shown).

After the completion of this compaction, water is sprinkled on the first improved soil 6 to adjust the water content ratio.

The base board 7 is constructed by taking an appropriate curing period.

A reinforcing material 8 formed in a lattice shape, a mesh shape or the like is arranged on the base board 7 (see FIG. 5).

As the reinforcing material 8, for example, plastic, rebar, bamboo, rope, cloth or the like is used. The reinforcing material 8 is basically formed in a lattice shape or a mesh shape, but it may be assembled in a single direction.

In this way, new quality sand 9 is laid on the base plate 7 on which the reinforcing material 8 is arranged in an appropriate thickness, and an appropriate amount of the solidifying material 10 is sprinkled on the new sand 9 ( (See FIG. 6).

The solidifying material 10 may be the same as the solidifying material 5 described above. The high quality new earth and sand 9 may be the same as the high quality new earth and sand 4 described above.

A new soil 8 is sprayed with an appropriate amount of the solidifying material 10 and mixed and stirred using the same excavator to obtain the second improved soil 11 (see FIG. 7).

The surface of the second improved soil 11 thus mixed and stirred is leveled by, for example, an excavation bucket of an excavator, and the second improved soil 11 is temporarily compressed.

After the temporary rolling pressure is completed, the level of the second improved soil 11 is measured, and the operator corrects the place where the level difference is large or the place where there is uneven mixing. Furthermore, the main rolling of the second improved soil 11 is performed using a roller or the like.

After the completion of this compaction, reconfirm the level of the second improved soil 11,
Water is sprayed on the second improved soil 11 to adjust the water content ratio.

Then, the upper ground 12 is constructed by taking an appropriate curing period.

In this way, the base plate 7 and the upper ground plate with the reinforcing member 8 interposed therebetween
The building ground 13 is composed of 12 and. A foundation or the like is built on this building ground 13.

It should be noted that one or a plurality of improved grounds may be further formed between the foundation ground 7 and the upper ground 12, and the reinforcing material 8 may be interposed between these improved grounds.

FIG. 9 shows a state in which the construction ground 13 configured as described above is bent due to unequal subsidence or the like. Reference symbols A, B, in the figure
Especially tensile force is generated in C.

Even if the ground is bent in this way, the reinforcing material 8 shares the tensile force of the soil and suppresses the tensile force of the soil, so that the rigidity of the ground is increased and cracks do not occur.

(Effect of the invention) A new high quality earth and sand is laid and improved on the ground from which the soft topsoil has been removed to form a foundation board, and a new high quality earth and sand is laid and improved again on this foundation board and above. And the upper ground, and a reinforcing material having a grid shape, a mesh shape, or the like is interposed between the base ground and the upper ground. Therefore, it is possible to obtain a building ground with improved compressive strength / shear strength and tensile strength.

Since the foundation is also made of high quality new earth and sand, it is possible to obtain a construction ground with higher compressive and shear strength.

Since the ground is improved over the entire area of the building site, not only the foundation part, but also the part where the meteorite is installed is strong.

Even if uneven subsidence occurs, the ground has tensile strength, so that the ground does not crack. Therefore, the building built on such ground is stable.

[Brief description of drawings]

1 to 8 show the procedure for carrying out the ground improvement method for construction of the present invention, FIG. 1 is a cross-sectional view of the building land, and FIG. 2 is a cross-sectional view of the existing ground over the entire area of the building, with the top soil removed. Fig. 3 is a cross-sectional view of laying new quality sand on the ground from which the top soil has been removed, and spraying solidifying material on this new quality soil, and Fig. 4 shows the first improved soil. Sectional view, fifth
Fig. 6 is a cross-sectional view of reinforcing material laid on the base plate, and Fig. 6 is a cross-sectional view of placing new quality sand on the base plate on which the reinforcing material is laid and spreading the solidifying material on the new earth and sand. FIG. 7 is a cross-sectional view of the second improved soil in which high-quality new earth and sand and solidifying material are mixed and stirred, and FIG. 8 is a cross-sectional view of the ground for construction completed by constructing the upper ground, and FIG. FIG. 4 is a cross-sectional view showing that the reinforcing material suppresses the tensile force of the soil even if the building ground completed in this way is unevenly settled. 1 ... Current ground, 2 ... Soil 3 ... Base bottom, 4 ... New quality sand 5,10 ... Solidifying material, 6 ... First improved soil 7 ... Underground board, 8 ... Reinforcing material 9 ... New good quality Sediment 11… Second improved soil, 12… Upper ground 13… Building ground A, B, C… Tensile force

Claims (1)

[Claims] 1. Excavation of the existing ground over the entire construction site to remove the topsoil, laying new quality sand on the base bottom of the ground from which the topsoil has been removed, and adding this new earth and an appropriate amount of solidifying material. After mixing and agitating the mixture, rolling is performed to form a base plate, and a reinforcing material formed in a lattice shape, a mesh shape, or the like is arranged on the base plate, and a new good-quality earth and sand is placed on the reinforcing material. Is laid to an appropriate thickness, the new earth and sand and an appropriate amount of the solidifying material are mixed and stirred, and then compacted to form the upper ground, thereby forming a building ground.