JPS63280111A - Ground improving work for building - Google Patents

Abstract

PURPOSE:To increase the strength of the ground by a method in which surface soil is removed, a reinforcing material is laid, and soil is newly placed on them to form an improved ground. CONSTITUTION:The surface soil 2 of all site area for building is removed, and a latticed or meshed reinforcing material 4 is laid. Good-quality of soil 5 is newly placed in an adequate thickness on the material 4 and mixed with a solidifying agent 6 with stirring, and the ground is tamped to form a ground 9 for building. The ground 9 having improved compressive strength, improved shear strength, and improved tensile strength for building can thus be obtained.

Description

[Detailed description of the invention] (°Industrial application field) The present invention relates to a method for improving construction ground.

(Conventional technology) Conventionally, there has been a method of improving the topsoil of the ground using a cement-based solidifying agent (referred to as conventional example 1), a method of strengthening the ground by adding reinforcing material (referred to as conventional example 2), and a method of strengthening the ground by adding reinforcing material during embankment. There is a construction method (called Conventional Example 3) that strengthens the ground by adding

(Problems to be Solved by the Invention) Conventional Example 1 has high compressive strength but lacks tensile strength, and has problems such as easy cranking into the ground when vertical compressive force is applied to the ground. Ta.

Conventional Example 2 had a problem in that the soil was disturbed when reinforcing material was inserted, which weakened the compressive strength.

Conventional Example 3 had problems such as insufficient compaction of the ground because reinforcing material was inserted into the embankment.

(Means for Solving the Problems) The present invention provides reinforcement by excavating the existing ground over the entire area of the construction site, removing topsoil, and forming a grid-like, mesh-like, etc. A building ground is created by placing new earth and sand of good quality on top of this reinforcing material to an appropriate thickness, mixing and stirring this new earth and sand and solidifying material, and then compacting it to form the building ground. This is an improved construction method.

(Function) Reinforcing materials are placed on top of the ground from which soft topsoil has been removed, and new, high-quality soil is poured on top of this to form the upper ground, increasing the compressive and shear strength of the ground. Increase tensile strength.

(Example) The drawings show an example of the construction ground improvement method of the present invention.

First, an excavator (not shown) or the like is used to excavate the current ground 1 in the entire area of the construction ground, and remove topsoil 2 to a depth of approximately 300 mm to 500 mm (see Figure 2).

The thickness of the topsoil 2 to be removed is 200 mm considering the softness of the topsoil 2.
In some cases, 0 is sufficient, and in other cases, 700 am is necessary.

A reinforcing material 4 formed in a lattice shape, mesh shape, etc. is placed on the base bottom 3 of the ground from which the topsoil 2 has been removed in this way (see FIG. 2).

As the reinforcing material 4, for example, plastic, reinforcing steel, bamboo, rope, cloth, etc. are used. The reinforcing material 4 is basically formed in a lattice shape or a mesh shape, but may also be formed in a single direction.

On top of the base bottom 3 on which the reinforcing material 4 has been placed, a suitable thickness of new soil 5 of good quality is laid down, and at the same time, an appropriate amount of solidification material 6 is sprinkled on top of this new soil 5 ( (See Figure 3).

As the new soil 5 of good quality, it is preferable to use well-drained mountain sand, river sand, sea sand, masa soil, etc. singly or in combination.

As the solidifying material 6, a ground stabilizing agent, cement, etc. are used alone or in combination. As the ground stabilization treatment agent, for example, Fujibeton (trade name of Keio Kaken Kogyo Co., Ltd.) or Asatsu Clean Set 1140 (trade name of Nippon Cement Co., Ltd.) is suitable.

An improvement of ±7 is achieved by mixing and stirring new soil 5 with an appropriate amount of solidifying material 6 sprinkled thereon using an excavator or the like (see Fig. 4).

The surface of the improved ±7 thus mixed and stirred is leveled using, for example, a packet of an excavator, and the improved ±7 is temporarily rolled.

After the preliminary rolling is completed, the level of improvement ±7 is measured, and the operator corrects areas where the level difference is large or where there is uneven mixing.

After correcting this level difference, etc., the improved ±7 is rolled to zero using a roller or the like (not shown).

After zero rolling pressure is completed, water is sprinkled on the improved ±7 to adjust the water content ratio.

The upper ground 8 is constructed by taking an appropriate curing period.

By constructing the improved upper ground 8 on top of the reinforcing material 4 disposed on the base bottom 3 in this manner, a building ground 9 is obtained (see FIG. 5).

Note that the upper ground 8 may be formed in multiple layers, and the reinforcing material 4 may be provided between each layer.

FIG. 6 shows a state in which the construction ground 9 constructed in this manner is bent due to the unevenness.

In particular, tensile forces are generated at symbols A, B, and C in the figure.

Even if the ground bends in this way, the reinforcing material 4 takes part in suppressing the tensile force of the soil, increasing the rigidity of the ground and preventing cracks from occurring.

(Effects of the invention) Reinforcing materials formed in a lattice shape, mesh shape, etc. are placed on the ground from which soft topsoil has been removed, and new soil of good quality is laid on top of this reinforcing material for improvement. It constitutes the upper ground. Therefore, it is possible to obtain a construction ground with increased compressive strength and shear strength as well as increased tensile strength.

Because the ground has been improved over the entire area of the building site, the strength of the ground is high not only in the foundation area but also in the area where the gables will be installed.

This ground has tensile strength, so even if uneven settlement occurs, cranks etc. will not enter the ground.

Therefore, buildings built on such ground are stable.

[Brief explanation of drawings]

Figures 1 to 5 show the implementation procedure of the ground improvement method for construction according to the present invention. Figure 1 is a cross-sectional view of the building site, and Figure 2 is a reinforcement material placed at the bottom of the base of the ground from which the topsoil has been removed. cross-sectional view,
Figure 3 is a cross-sectional view of the base bottom with reinforcing material placed on top of which new soil of good quality is poured and solidification material is sprinkled on top of this new soil. Cross-sectional view of improved soil made by mixing and stirring new soil and solidification material, No. 5
The figure is a cross-sectional view of the completed construction ground that forms the upper ground.
FIG. 6 is a sectional view showing that the tensile force of the soil is suppressed by the reinforcing material even if the construction ground completed in this manner undergoes uneven settlement. 1... Current ground 2... Topsoil 3...
・Base bottom 4...Reinforcement material 5...New soil of good quality 6...Solidification material 7...Improvement ±
8... Upper ground 9... Construction ground A, B, C... Tensile force figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1) Excavating the current ground over the entire area of the construction site to remove topsoil, and arranging reinforcing material in the form of a lattice, mesh, etc. at the bottom of the base of the ground from which the topsoil has been removed; Ground improvement for construction, characterized by laying new high-quality earth and sand to an appropriate thickness on top of this reinforcing material, mixing and stirring the new earth and sand and solidifying material, and then compacting it to form the ground for construction. Construction method.