JPH04108911A - Foundation piling method - Google Patents

Abstract

PURPOSE:To prevent a pile from being eroded by driving a resin pipe in harmful soil under pressure while the soil is drilled, and forming soil-cement slurries between the resin pipe and the pile during piling by cement-milk method. CONSTITUTION:A resin pipe 1 is driven into harmful soil under pressure until it reaches good soil while earth and sand in the harmful soil are removed. Then a screw auger 7 drills the good soil while it discharges a cement solution from its tip. Further, soil-cement slurries obtained by stirring the cement solution and the earth and sand of good quality by the screw auger 7 are accumulated inside the resin pipe 1 through the windows of a casing 3. Thereafter, a pile is inserted, and the soil-cement slurries are raised to be filled between the resin pipe 1 and the pile. Thus, since the soil cement of good quality can be formed and the harmful soil is shut off by the resin pipe 1, the pile and its surroundings can be protected from erosion.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to the construction of a pile foundation by penetrating through toxic soil that contains strong acidic soil, sulfate ions, etc. and corrodes the pile material. This is a construction method for preventing pile erosion.

It can be used as the foundation for buildings in hot spring areas.

[Conventional method] Currently, no method has been established to prevent erosion of foundation piles in strongly acidic soil or soil containing sulfates. In such soils, steel piles are more susceptible to corrosion than concrete piles, so you have to rely on concrete piles.However, even for concrete piles, the standards regarding the materials used for piles and the mix of concrete must be applied mutatis mutandis. There was no drastic construction method.

[Problems to be solved by the invention] Increasingly, buildings are being built on toxic soil that severely erodes concrete and steel, such as in hot spring areas. The present invention is a foundation construction method that can be handled using conventional pile materials, and is intended to solve the problem of preventing pile erosion at construction sites.

[Means for solving the problem] / When constructing piles through hazardous soil, first install resin concrete pipes or steel pipes whose surfaces are sealed with resin, depending on the depth of the hazardous soil. Press fit the pipe (1) and remove most of the harmful soil inside the pipe.

21 Next, excavation is performed from the inner bottom of the resin pipe (1) to the depth of the pile using the cement milk injection method, and the injected cement solution and harmless earth and sand are sufficiently mixed and stirred to form a high-quality soil cement 1-slurry. After creating the pile, when the pile is inserted into the hole, high quality soil cement slurry rises from the bottom according to the volume of the pile and flows into the resin pipe (1) and the pile (2).
) will fill the gap between the

3. When the soil cement slurry (5) solidifies, the pile (
2) The entire length of the area is surrounded by high-quality soil cement.

As described above, the present invention includes a resin pipe (1), a resin pipe and a pile (
2) This is a construction method that permanently protects the pile from harmful soil by solidifying high-quality soil-cement slurry that fills the gap between the pile and the pile.

[Function] An effective measure to deal with soil that is harmful to piles is to surround the pile with soil cement, but if the soil used to create soil cement is harmful soil, the effectiveness of this method may be reduced. cannot be expected.

Therefore, the present invention is designed to press-inject a resin pipe (1) into the stratum of hazardous soil, excavate the inside of the pipe, and then excavate the inside of the pipe to create a good material when constructing a pile (2) using the cement milk injection method. Pour the soil cement slurry (5) into the resin pipe (
The soil-cement slurry does not contain harmful soil and is made from high-quality soil and sand because it is a construction method that prevents erosion of the pile by raising it into the gap between 1) and the pile (2) and waiting for this solidification to prevent erosion of the pile.

In addition, soil cement around piles in hazardous soil is
Since the pile is surrounded by resin pipes, no harmful ions will permanently permeate through it, so the consolidation of the soil cement can be expected to provide horizontal resistance to the pile.

Therefore, even if conventional commonly used piles are used,
If this method is used, a pile foundation that will not be eroded can be expected.

[Example code] This will be explained using figures.

/ As shown in Figure 1, the resin pipe (
1), and press-fit to a depth that penetrates the harmful soil while excavating the harmful soil inside. During the excavation, harmful soil inside the resin pipe is discharged as carefully as possible using, for example, a barracket (6).

4. After draining the hazardous soil from inside the pipe, set a commonly used construction machine for the cement milk injection method, such as a screw auger machine with a casing, to the pile core as shown in Figure 2, and then press the tip of the screw auger. While discharging more cement solution, start drilling into the good quality soil at the bottom of the resin tube.

3. During drilling, the cement solution and high-quality soil discharged from the auger tip become a high-quality soil-cement slurry through the stirring action of the screw auger rotation.
While some of it escapes between the periphery of the casing and the soil, most of it rises within the casing and is accumulated in the resin pipe through the window (4) in the casing.

In this case, no harmful soil is mixed into the soil-cement slurry that is created.

After continuing excavation to a predetermined depth in this manner, the auger is pulled up while stirring.

After the auger is raised, as shown in Figure 4, the area from the vicinity of the tip of the pile to the inside of the resin pipe will be filled with high-quality soil-cement slurry that does not contain harmful soil.

6. After that, the conventionally used piles are inserted, and after reaching a predetermined depth, wait for the soil cement to harden and complete the construction.

[Effects of the Invention] As described above, according to the present invention, a resin pipe is press-fitted into harmful soil, and after the harmful soil inside is discharged, a pile is constructed using the cement milk injection method.

/ Soil cement does not contain harmful soil and will not be eroded in the future.

Since the toxic soil is blocked by resin pipes, it does not directly erode the soil cement around the piles.

3. Since the soil below the hazardous soil is of good quality, the piles and soil cement will not be eroded.

Yes, you can use conventional general piles.

Therefore, if the hazardous soil is relatively shallow compared to the pile length,
It's extremely economical.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the situation during press-fitting of a resin pipe. FIG. 2 is an explanatory diagram showing the state of the screw auger with a sink set at the pile core position at the bottom of the resin pipe. FIG. 3 is an explanatory diagram of the situation in which excavation is performed while creating soil cement 1 to slurry. FIG. 4 is an explanatory diagram showing the filling situation of soil cement slurry. FIG. 5 is an explanatory diagram showing the situation after the pile is inserted. (1) is a resin pipe, (2) is a pile, (3) is a casing, (
4) is the window of the casing, (5) is the soil cement slurry, (6) is to the excavation bucket 1, (7) is the screw auger

Claims (1)

[Claims] Resin concrete pipes with an inner diameter larger than the pile diameter used, or resin pipes such as steel pipes whose surfaces are sealed with resin (
1) is press-fitted into the ground that is harmful to the material of the pile to remove the harmful soil inside the pipe, and then the pile (2) is constructed inside the pipe using the cement milk injection method. ) and the resin pipe (1) is filled with high-quality soil cement (5) made during pile construction.