JPH08209678A - Ground improvement method and construction method of pile or underground wall - Google Patents

Abstract

(57) [Summary] [Purpose] It is not necessary to dispose of earth and sand or muddy water at the time of drilling, and stable materials can be supplied, so the quality of piles and ground improvement can be easily improved, To provide a ground improvement method capable of constructing a good column row wall, and a method of constructing a pile or an underground wall [Configuration] A ground improvement method and a pile construction method of the present invention,
It is characterized by excavating auger 11 to a predetermined depth while discharging earth and sand, manufacturing soil mortar from the earth and sand discharged on the ground, and injecting soil mortar 32 from the tip of the auger into the drilling hole while pulling up auger 11. And Further, the method of constructing the underground walls 35, 36 of the present invention is to excavate the auger 11 to a predetermined depth while discharging the earth and sand, to manufacture soil mortar with the earth and sand discharged to the ground, and to lift the auger 11 while the auger is being pulled up. It is characterized in that soil mortar is injected into the drilled hole from the tip to construct a pile, and a plurality of piles 33 are consecutively constructed in the same process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement method and a pile or underground wall construction method.

[0002]

2. Description of the Related Art At present, a CFA (Continuous Flight Auger) method is proposed as a method for constructing a pile or an underground wall. This method uses a large-diameter auger (pile drilling machine) to drill holes to a specified depth to discharge the earth and sand, and while pulling up the auger, inject concrete and mortar from the tip, and then rebar or shaped steel that becomes the core material. Is a method of constructing cast-in-place piles and column walls by inserting into concrete or mortar. That is, in the CFA method, the earth pressure applied to the hole wall at the time of drilling was supported by the auger, and the earth and sand were completely replaced in the drilled hole by concrete or mortar to construct the piles and column walls, which were then discharged. Discard the earth and sand.

In addition to this, as a construction method used for backfilling of excavated trenches and holes, there is a method of adding cement, water or the like to the earth and sand discharged to the ground at a construction site and using it as a soil mortar. In this method, a bucket or earth drill is used to excavate grooves or holes while preventing the collapse of the hole wall with a stable liquid such as bentonite mud, and the soil mortar is placed in the grooves or holes to produce bentonite mud or the like. This is a method of replacing soil mortar.

[0004]

However, in the above-mentioned conventional CFA method, the discharged earth and sand have to be discarded, which causes a problem that the construction cost increases. In addition, in the case of a pillar row wall formed by connecting piles in series, it is difficult to cut the concrete or mortar that has been placed first, and it is difficult to cut it, and the waterproofing between adjacent piles However, there is a problem in that Furthermore, since a concrete pump car with a boom is used for placing concrete, a relatively large construction space is required, and the cost is increased.

In the conventional method using soil mortar, a mud making plant, a mud water treatment plant, a tremie pipe or a concrete pouring height measuring device, and a crane or the like for building or pulling out the tremie pipe are installed. Will be required and the construction cost will increase. Further, since the soil mortar is cast in bentonite muddy water, there is a problem in that quality control is difficult because of the high technology required for casting and muddy water management. Furthermore, there is also a problem that a huge amount of bentonite mud must be treated as a waste liquid.

Therefore, the present invention has been made in view of the above-mentioned problems, and its purpose is to eliminate the need to discard most of the earth and sand and mud water generated during drilling and to supply a stable material, so that the piles And a ground improvement method, which can easily improve the quality of ground improvement, and can obtain a seam with good waterproofness when constructing a column wall, and a method for constructing a pile or an underground wall. To provide.

[0007]

The present invention has been made in view of the above object, and its gist is to excavate an auger to a predetermined depth while discharging earth and sand to the ground, and to remove soil with the earth and sand discharged to the ground. It is a method for ground improvement and a method for constructing piles, which comprises producing mortar and injecting the soil mortar into the drilling hole from the tip of the auger while pulling up the auger. Further, another gist of the present invention is to excavate an auger to a predetermined depth while discharging earth and sand to the ground, to manufacture a soil mortar with the earth and sand discharged to the ground, and while pulling up the auger, the soil mortar from the tip of the auger. It is a method of constructing an underground wall, which is characterized in that it is injected into a drilled hole to construct a pile, and a plurality of piles are consecutively constructed in the same process.

[0008]

In the method of constructing a pile according to the present invention, first, an auger of an excavator is drilled to a predetermined depth. At this time, the hole wall in the drill hole is maintained so as not to be collapsed by the auger filled with earth and sand during the flight. Next, while pulling up the auger, the soil mortar produced by using the earth and sand generated in the previous step is pumped by a pump through the pipe and the inside of the auger, and is injected into the drilled hole from the tip of the auger. This time,
The hole wall in the drilled hole is maintained so as not to be collapsed by the auger and the poured soil mortar. Here, the earth and sand are scraped off when the auger is pulled up, and transported by the transporting means to the soil mortar blending plant provided in the stockyard. The transported earth and sand is mixed with a predetermined amount of cement and water, or if necessary, bentonite or the like, and mixed as soil mortar.
The soil mortar thus produced is supplied to the pump of the excavator by the conveying means. After the soil mortar is filled in the drilled hole, a reinforcing rod cage or shaped steel as a core material is inserted into the hole to construct a pile. Moreover, when constructing an underground wall, it is sufficient to form a plurality of piles by the above-mentioned steps and to connect them in series. Further, even when the ground is improved, it is possible to improve the ground to be stable by constructing a plurality of piles in the predetermined site by the above-described process.

[0009]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a side view of an apparatus used for the ground improvement method and the pile or underground wall construction method of the present invention. In FIG. 1, an excavator 1 includes, for example, an auger 11 in which a blade (flight) is spirally formed on a large-diameter pipe body.
(Outer diameter of about 500 to 1200 mm), a boom 14 that erects and supports the boom 14, supports the boom 14, and the excavator 1
A base machine 15 that moves the whole body, a rotary press-fitting device 10 that is provided on the upper end of the auger 11 and press-fits into the ground while rotating the auger 11, and a lower part of the boom 14, and the left-right direction when the auger 11 is moved up and down. And an auger guide 12 that scrapes off the earth and sand when pulling up the auger 11. Further, the excavator 1 has a pump 1 as a pumping means for pumping soil soil mortar into the auger 11 via a hose 13.
7 and an unwinding and winding device 16 for the hose 13. In the construction method of the present invention, the auger guide 1
A residual soil carrier 20 such as a belt conveyor for transporting the soil scraped off by 2 is arranged at the drilling port.

Next, the method of constructing a pile according to the present invention will be described with reference to FIG. As shown in FIG. 2, first, the tip of the auger 11 of the excavator 1 is aligned with the planned pile formation point on the construction site, and the residual soil carrier 20 is installed around the auger 11.

Next, as shown in FIG. 2, the auger 11 is pressed into a predetermined depth while being rotated by the rotary press-fitting device 10. At this time, the hole wall in the drilled hole is maintained so as not to be collapsed by the large-diameter auger 11 filled with earth and sand during the flight.

Then, as shown in FIG. 2, while pulling up the auger 11, the soil mortar supplied to the pump 17 is pressure-fed through the hose 13 and the inside of the auger 11, and injected into the drilled hole 31 from the tip of the auger 11. To do. At this time, the hole wall in the drilled hole is maintained by the auger 11 and the poured soil mortar 32 so as not to collapse. Here, the poured soil mortar is manufactured by using the earth and sand generated in the previous step. Also, this auger 11
When pulling up, the soil sandwiched between the flights is scraped off by the auger guide 12, and the soil mortar blending plant (in the stockyard inside or outside the construction site with the residual soil carrier 20 shown in FIG. (Not shown). In addition to this, the residual soil can be transferred from the residual soil carrier 20 by loading it on a dump according to the size of the construction site, or directly using the backhoe without using the residual soil carrier 20. The earth and sand transported to the soil mortar blending plant are measured for particle size, silt content, water content, etc., and are weighed and put into an agitator (not shown). At the same time, a predetermined amount of cement and water, or cement milk in which bentonite or the like is mixed depending on the measured value is added to the stirrer. The stirrer mixes the soil and cement milk that have been put in, mixes the soil mortar, and stores it in a storage tank. The soil mortar thus manufactured is supplied to the pump 17 of the excavator 1 by a pump, a ready-mixed concrete vehicle or the like.

By filling the inside of the drilled hole 31 with soil mortar and inserting a rebar cage or shaped steel (not shown) as a core material into this hole, a cast-in-place pile is constructed.

In the case of constructing an underground wall, a plurality of cast-in-place piles 33 may be formed and connected in series by the above-described process, for example, in the arrangement shown in the plan views of FIGS. . Since the pile of the present invention is formed of soil mortar, when constructing the pile at a position in contact with the pile constructed in advance, the auger 11 makes a hole while easily cutting the outer peripheral portion of the preceding pile. By filling the hole with soil mortar, it is possible to form the column row walls 35 and 36 having good integration with the preceding piles and good water blocking property, or column row walls of other arrangements. .

Further, even when the ground is improved, if a plurality of piles are constructed in the predetermined site by the above process,
It can be improved to a stable ground.

[0016]

INDUSTRIAL APPLICABILITY The ground improvement method and pile construction method of the present invention are drilled with an auger, a soil mortar is produced from the earth and sand discharged by the auger, and the soil mortar is pulled out from the tip while pulling out the auger. Pouring into the drill hole, the hole wall in the drill hole is always supported by the auger or / and soil mortar. Therefore, it is not necessary to fill the drill hole with bentonite mud or the like in order to prevent the collapse of the hole wall. Therefore, a tremy for pouring mud plant or mud treatment plant for this bentonite mud, concrete, etc. It is not necessary to use a pipe, a driving height measuring device, and a crane or the like for installing and extracting a tremie pipe, and it is possible to significantly reduce the space and the facility cost for installing these facilities.

Further, since soil mortar is produced in a plant on the ground by using the earth and sand produced during drilling, it is possible to produce high quality soil mortar, and further, in the drilling where there is no liquid such as bentonite muddy water. Since the soil mortar is directly injected into the ground, the ground can be improved and the quality of the pile can be improved. Furthermore, the amount of earth and sand to be disposed of can be greatly reduced, and the total amount of earth and sand discharged is 20 to 30
It is enough to dispose about%.

Furthermore, when constructing an underground wall by means of a column wall, etc., since each pile is constructed with soil mortar,
You can easily drill the outer peripheral part of the leading pile with an auger and fill the hole with soil mortar to form a column wall that has good seam integrity and good waterproofness. You can

[Brief description of drawings]

FIG. 1 is a side view of an apparatus used in the ground improvement method and the pile or underground wall construction method of the present invention.

FIG. 2 is a side view for explaining the ground improvement of the present invention and the steps of constructing a pile or an underground wall.

FIG. 3 is a plan view of an underground wall formed by the construction method of the present invention.

[Explanation of symbols]

 1 Excavator 11 Auger 32 Soil mortar 33 Pile 35, 36 Column wall (underground wall)

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kimiaki Ishihara 2-5-8 Kita-Aoyama, Minato-ku, Tokyo In-group (72) Inventor Yuetsu Kikuchi 2-5-8 Kita-Aoyama, Minato-ku, Tokyo (72) Inventor Kaoru Hirose 1-6 Shioda-cho, Kochi City

Claims (2)

[Claims] 1. A soil mortar is excavated to a predetermined depth while being discharged to the ground, a soil mortar is manufactured from the soil discharged to the ground, and the soil mortar is injected into a drilling hole from the tip of the auger while pulling up the auger. A method for improving the ground and a method for constructing a pile. 2. An auger is excavated to a predetermined depth while discharging the earth and sand, and a soil mortar is manufactured from the earth and sand discharged on the ground, and the soil mortar is injected into a drilling hole from the tip of the auger while pulling up the auger. Then, a pile is constructed, and a plurality of piles are consecutively constructed in the same process to construct the underground wall.