JPH0751768B2 - 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 existing ground over the entire construction site to remove the topsoil, spray an appropriate amount of a solidifying material on the base bottom of the ground from which the topsoil has been removed, and solidify the solids. After mixing and stirring the material and the base bottom excavated to an appropriate depth, rolling is performed to form the base plate, and a reinforcing material formed in a lattice shape, a mesh shape, or the like is arranged on the base plate. A new earth and sand of good quality is laid on the reinforcing material to an appropriate thickness, and the new earth and sand and an appropriate amount of solidifying material are mixed and stirred, and then compacted to form the upper ground to form the building ground. It is a ground improvement method.

(Function) By arranging a reinforcing material between the ground improved ground and the upper ground, the tensile strength as well as the compressive strength / shear strength of the ground is 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 500 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 700
It may be necessary for about mm.

In this way, an appropriate amount of the solidifying material 4 is sprayed on the base bottom 3 of the ground from which the top soil 2 has been removed (see FIG. 3). As the solidifying material 4,
The ground stabilization agent, cement, etc. may be used alone or as a mixture. As a 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.)
Etc. are suitable.

The base bottom 3 on which an appropriate amount of the solidifying material 4 has been sprinkled is similarly excavated by an excavator to a depth of about 300 mm to 600 mm, and the excavated soil 5 and the solidifying material 4 are mixed and stirred to obtain the first improved soil 6 (No. 1). (See Fig. 4).

The surface of the first improved soil 6 thus mixed and stirred is leveled by, for example, a hugget of an excavator, and the first improved soil 6 is temporarily rolled.

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 4 described above. As the high quality new earth and sand 9, it is preferable to use well-drained mountain sand, river sand, sea sand, Masa earth, etc. alone or in combination.

A new soil 9 is sprayed with an appropriate amount of the solidifying material 10 by using an excavator in the same manner to mix and stir to make a 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.

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) The upper ground improved by laying a new good quality earth and sand on the existing ground by removing the soft ground soil and improving the existing ground to an appropriate depth. In the above, a reinforcing material having a lattice shape, a mesh shape, or the like is interposed between the base board and the upper ground. Therefore, it is possible to obtain a building ground with improved compressive strength / shear strength and tensile 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 the solidified material scattered on the base bottom of the ground from which the top soil has been removed, Fig. 4 is a cross-sectional view of the first improved soil, and Fig. 5 is a cross-sectional view of laying a reinforcing material on the base soil, Fig. 6 is a cross-sectional view in which new quality sand is put on a baseboard on which a reinforcing material is laid, and a solidifying material is sprinkled on this new sand, and Fig. 7 shows a new quality sand and solidifying material. Cross-sectional view of the second improved soil mixed and stirred,
Fig. 8 is a cross-sectional view of the building ground that is completed by constructing the upper ground, and Fig. 9 is the tensile force of the soil due to the reinforcing material even if the building ground completed in this way is unevenly settled. It is sectional drawing which shows suppressing. 1 ... Current ground, 2 ... Soil 3 ... Base bottom, 4,10 ... Solidification material 5 ... Excavation soil, 6 ... First improved soil 7 ... Substrate, 8 ... Reinforcement material 9 ... New quality sand, 11 ... Second improved soil 12… Upper ground, 13… Construction ground A, B, C… Tensile force

Claims (1)

[Claims] 1. Excavation of the existing ground over the entire construction site to remove the topsoil, and an appropriate amount of a solidifying material is sprayed on the base bottom of the ground from which the topsoil has been removed, and the solidification material and an appropriate depth are excavated. After mixing and stirring the base bottom, 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. Construction method by laying different earth and sand to an appropriate thickness, mixing and stirring the new earth and sand and an appropriate amount of solidifying material, and then rolling to construct the upper ground to form the building ground .