Method for improving ground

Abstract

A method for improving ground is capable of improving the strength or quality of an underground consolidated body formed by reducing the ratio of water to a “rich-mixed” solidification material (a cement) (W / C), assuredly carrying the solidification material from a feed source to a jet device, and reducing the amount of solidification material treated as an industrial waste in a construction process. The method for improving ground includes a step of drilling a drilling hole in the ground to be improved, a step of moving (pulling up) a jet device in a vertical direction by rotating the same while the jet device is inserted into the drilling hole and a fluid for cutting the ground (a stable liquid or a partition forming material) is injected from the jet device, and a step of injecting a solidification material from the jet device.

Description

TECHNICAL FIELD[0001]The present invention relates to a ground improvement technology that forms an underground consolidated body by cutting (in-situ) soil in the ground to be improved and mixing water and a solidification material such as cement and agitating a mixture thereof.BACKGROUND[0002]A technology for forming an underground consolidated body of a cylindrical shape by drilling a drilling hole in a ground to be improved, moving (pulling up or pushing down) a jet device in a vertical direction by rotating the same while the jet device is inserted into the drilling hole and a high-pressure fluid such as water is injected in an outward radial direction from the jet device to cut an in-situ soil, and by mixing the cut soil and a solidification material such as a cement and agitating a mixture thereof by injecting or delivering the solidification material to the soil has widely been known (e.g. Patent Document 1).[0003]In order to improve the strength (quality) of an underground c...

AI Technical Summary

Benefits of technology

The present invention provides a method for improving the strength of an underground consolidated body formed from a rich-mixed solidification material. This is achieved by using a separation layer composed of a partition forming material, which reduces the contact between the solidification material and the mixture of stabilized liquid and cut soil, resulting in a slurry that is mostly composed of the stabilized liquid and cut soil. This reduces the amount of solidification material that needs to be discharged above the ground, saving construction costs. Overall, this method improves the quality and strength of the underground consolidated body.

Problems solved by technology

However, a lower W / C might lead to more viscosity of a mixture of water and a cement, thereby blocking a carrying passage from a cement feed source to a jet device.

Thus, it is difficult to carry a solidification material to the jet device.

In addition, all of a solidification material injected from a jet device is not solidified underground and large amounts of the solidification material are discharged above the ground as a slurry.

Also, if a solidification material is “rich-mixed” with a low W / C, large amounts of the solidification material will be treated as an industrial waste, resulting in an increase in construction costs accordingly.

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