JPH0574644B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a ground improvement method for construction aimed at preventing uneven settlement of buildings due to soft ground or destruction of concrete foundations.

(Prior Art) Conventionally, when constructing a house or the like on soft ground, ground countermeasures have been taken using slab foundations, pile foundations, etc.

(Problems to be Solved by the Invention) A solid foundation is effective in sandy ground, and in clay ground it is effective in reducing the ground contact thickness, but the construction cost is extremely high and it is uneconomical.

In addition, pile foundations cause environmental pollution problems due to noise and vibration during driving, and the construction cost is considerably higher than the total building cost, making it an uneconomic construction method.

(Means for solving the problem) The construction ground improvement method of the present invention excavates the existing ground over the entire area of the construction site and removes the topsoil with a thickness of approximately 300 to 500 mm. After scattering an appropriate amount of solidification material on the base bottom of the ground, excavate the base bottom to a depth of about 300 to 600 mm, mix and stir the excavated soil and solidification material, and make the improved soil mixed and stirred in this way. Level the surface and perform temporary rolling pressure.
Next, after adjusting the level of the improved soil surface, main compaction is performed, and the main compacted improved soil is sprinkled with water to adjust the moisture content and then cured.

(Operation) The topsoil, which is generally soft, is removed over the entire area of the construction site, and an appropriate amount of solidification material is sprinkled on the base bottom of the removed ground, and this solidification material and the excavated soil are added to the base bottom. Improving the ground for construction by mixing and stirring.

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

First, an excavator 1 is used to excavate the existing ground 2 over the entire area of the construction site, and topsoil 3 with a thickness of about 300 to 500 mm is removed. Considering the softness of the topsoil 3, the thickness of the topsoil 3 to be removed may be 200 mm, or about 700 mm may be necessary.

The base bottom 4 of the ground from which the topsoil 3 has been removed in this way
An appropriate amount of solidifying material 5 is sprinkled on the area. As the solidifying material 5,
Ground stabilization agents, cement, etc. are used alone or in combination. As the ground stabilizing agent, for example, Fujibeton (trade name of Keio Kaken Kogyo Co., Ltd.) or Asano Clean Set 1140 (trade name of Nippon Cement Co., Ltd.) is suitable.

The base bottom 4, on which an appropriate amount of solidification material 5 has been sprinkled, is similarly excavated to a depth of approximately 300 to 600 mm using the excavator 1, and the excavated soil 6 and solidification material 5 are mixed and stirred to obtain improved soil 7 ( (See Figure 3).

The surface of the improved soil 7 mixed and stirred in this manner is leveled using, for example, the excavation bucket 1a of the excavator 1, and the improved soil 7 is temporarily compacted.

After the preliminary compaction is completed, measure the level of the improved soil 7,
The operator corrects areas where there is a large level difference or uneven mixing.

Further, the improved soil 7 is subjected to main compaction using a rammer 8, rollers 9, etc.

After the main compaction is completed, the level of the improved soil 7 is reconfirmed, and water is sprinkled on the improved soil 7 to adjust the water content ratio.

After a suitable curing period, the ground improvement is completed.

The foundation will be constructed on the ground that has been improved as described above.

(Effect of the invention) The construction ground improvement method of the present invention removes the topsoil of the existing ground over the entire area of the construction site to an appropriate depth,
The ground from which this topsoil has been removed is improved using a solidification material. Therefore, since the topsoil, which is soft ground, is removed, the improvement effect is enhanced and the building can be constructed on stable ground.

[Brief explanation of the drawing]

The drawings show an embodiment of the ground improvement method for construction according to the present invention. Fig. 1 is a cross-sectional view of the current ground being excavated using an excavator, and Fig. 2 is an enlarged cross-section of the excavated ground with solidification material sprinkled on the bottom of the base. Figure 3 is a cross-sectional view of the bottom of the base on which solidification material has been sprinkled, excavated to an appropriate depth, mixed and stirred to form improved soil, and Figure 4 is a cross-sectional view of a worker leveling the surface of the improved soil. 5 is a cross-sectional view showing improved soil being compacted using a rammer, and FIG. 6 is a cross-sectional view showing improved soil being compacted using rollers. 1...Excavator, 2...Current ground, 3...Top soil,
4... Base bottom, 5... Solidification material, 6... Excavated soil,
7...improved soil, 1a...excavation bucket, 8...ranma, 9...roller.

Claims (1)

[Claims] 1 Excavate the current ground throughout the entire construction site and excavate approximately
After removing the topsoil with a thickness of about 300 to 500 mm and spraying an appropriate amount of solidification material on the base bottom of the ground from which the top soil was removed, excavate the base bottom to a depth of about 300 to 600 mm. The excavated soil and solidification material are mixed and stirred, and the surface of the mixed and stirred improved soil is leveled and preliminary compaction is performed. Next, after adjusting the level of the improved soil surface, main compaction is performed. A construction ground improvement method characterized by curing the compacted improved soil by sprinkling water on it to adjust the moisture content.