JPH1161799A - High pressure jet agitation pile method by two or more jet nozzles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To halve the jetting time necessary for forming a columnar soidified body and the number of lifting times of a jet-injection device, by arranging two jet nozzles at the upper and lower positions with a distance equal to the unit excavating thickness, in a jet- injection device used for excavation in common. SOLUTION: A jet-injection device used for excavation in common is connected to a triple- structural injection pipe to form a high pressure water passage 8, an air passage 9, and an injection passage 10. And two jet nozzles 11 are arranged at the upper and lower positions with a distance equal to the unit excavating thickness and the injection nozzle 20 is arranged thereunder. An air nozzle 15 is arranged at the periphery of the high pressure nozzle 14 to constitute the jet nozzles 11. An air check valve 12, an injection check valve 21, and a high pressure check valve composed of an extensible circular valve, are arranged between respective passages and the nozzles. Accordingly, an excavating thickness two times an ordinary thickness can be obtained with one time of jetting operation. The jetting time necessary for forming a columnar solidified body and the number of lifting times of the jet-injection device can be reduced by half to curtail the working time. And further, Jamming resulting from the reverse flow of underground water or soil from respective nozzles can be prevented by the check valves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
Attach a jet injection device to the tip of the injection tube, send high-pressure liquid and compressed air through the injection tube swivel at the top of the injection tube, and simultaneously jet high-pressure liquid and compressed air from the injection nozzle of the injection injection device. At the same time, the soil of the ground in the predetermined formation range is cut, and at the same time, the predetermined formation range is solidified and formed in a columnar shape with the cement-type solidification material liquid by the cement-type solidification material liquid injected from the high-pressure nozzle or the injection nozzle of the injection and injection device. ,
The present invention relates to a high-pressure injection stirring pile method.

[0002]

2. Description of the Related Art As a known technique of using a triple pipe as an injection pipe, a casing pipe is previously drilled to a predetermined formation start position by a drilling machine, and an injection pipe is provided in the casing pipe and an injection injection device is provided at a tip of the injection pipe. After inserting and inserting the casing tube, replace the drilling machine and the forming machine,
High-pressure water and compressed air are sent to the inner pipe flow path of the injection pipe and the compressed air to the middle pipe flow path through the injection pipe swivel at the top of the injection pipe, and are injected from the injection nozzle of the injection injection device to form a ground of a predetermined formation area. While cutting the sediment, the cement-based solidifying material liquid is simultaneously sent to the outer pipe flow path of the injection pipe while the cut soil is discharged as slime, and the cement-based solidifying material liquid is injected from the injection nozzle of the injection injection device, and the injection pipe is discharged. In the case of a column jet method in which a predetermined formation range is intermittently raised by a predetermined rotation speed and injection time and a predetermined formation range is solidified and formed with a cement-based solidifying material liquid in a column shape, or when a double pipe is used as an injection pipe, Attach the injection injection device to the tip of the injection pipe, insert a hole to the predetermined formation start position, and through the injection pipe swivel at the top of the injection pipe, from the inner pipe flow path of the injection pipe as a high-pressure liquid, cement-based solidified material. Pressure from the liquid and outer pipe flow path Sending air, simultaneously cutting from the injection nozzle of the injection injection device to cut the soil of the ground in the predetermined formation range, and the injection pipe was intermittently rotated up by the predetermined rotation speed and injection time to cut the predetermined formation range There is known a JSG method and the like in which solidification and formation are performed in a columnar shape using earth and sand and a cement-based solidifying material liquid.

[0003]

According to the conventional method using a multi-pipe as an injection pipe, the injection and injection apparatus at the tip of the injection pipe has one injection nozzle composed of a combination of a high-pressure nozzle and an air nozzle containing a high-pressure nozzle. Yes, high pressure liquid and high pressure liquid are simultaneously injected from the high pressure nozzle and air nozzle of the injection injection device inserted into the ground, and the injection pipe is rotated at a predetermined number of revolutions while rotating the injection pipe at a predetermined time and unit cutting thickness according to the ground cutting capacity. The height is raised as a unit pulling interval, and a predetermined formation range is solidified and formed into a column shape with a cement-based solidifying material liquid. For example, in the conventional method using a triple pipe as an injection pipe, the injection nozzle in the injection and injection apparatus has a capacity of 70 l / min of fresh water as a high pressure liquid at a pressure of 400 kg / cm ² and a compressed air of 7 kg / cm ² as a high pressure liquid. Inject at a discharge rate of 1.5 m ² / min,
The unit lifting interval is set to 2.5 cm, which is equal to the unit cutting thickness, and the unit is intermittently rotated and raised at a speed of 30 seconds per unit lifting interval. In this case, there are 40 intermittent pulling outs of the injection time of 20 minutes per 1 m of growth, and 3.
It requires cement solidifying material liquid amount of 6 m ^3, further 5m
^This results in more than ^three slimes being discharged. However, with the recent increase in the scale of civil engineering construction work, ground improvement work by high-pressure injection agitation method has also been performed at a large depth, and in the above-mentioned conventional method, the drilling distance has increased while the ground characteristics have also been strengthened. In addition to this, there is a problem that the construction efficiency is greatly reduced, such as the effective diameter of the formation is 2 m or less, and the work of attaching and detaching the injection pipe or the injection pipe swivel increases, so that each nozzle in the injection injection device is blocked. And the workability deteriorates. Further, in the conventional construction method using the triple pipe, the earth and sand cut by the high-pressure jet of the injection nozzle of the injection injection device is sequentially discharged from a slime discharge path around the injection pipe, and is treated as industrial waste in the processing. Because of the necessity, it is an urgent issue to reduce the amount in terms of environmental protection. Furthermore, since the amount of cement-based solidifying material liquid equal to the amount of sediment cut and discharged by the high-pressure jet of the injection nozzle is injected from the injection nozzle, the strength of the consolidated body in the formation range is generally excessively large with respect to the design strength. However, there was also a problem in terms of economy.

[0004]

In order to solve the above-mentioned problems, the present invention has an injection pipe having a multi-layer structure and an injection injection device at the tip thereof. The injection injection device has a high-pressure nozzle communicating with a high-pressure channel. A plurality of injection nozzles each including a combination of air nozzles including the high-pressure nozzle and communicating with an air flow path at intervals equal to a unit cutting thickness in a direction perpendicular to the axis of the injection injection device; Below the injection nozzle, there is an injection nozzle that communicates with the injection flow path, and comprises a stretchable annular valve between the high pressure flow path and the high pressure nozzle, between the air flow path and the air nozzle, and between the injection flow path and the injection nozzle. Each pump has a check valve, which sends high-pressure liquid to the high-pressure flow path and compressed air to the air flow path through the injection pipe swivel attached to the top of the injection pipe, and also feeds the injection material liquid to the injection flow path. Note that consists of a building machine After the injection pipe and the injection injection device are inserted in advance at the formation start position by the above-mentioned formation machine, the high-pressure liquid and the compressed air are simultaneously injected from the injection nozzle while the injection pipe is rotated at a predetermined rotation speed, and the injection is performed. While injecting the injection material liquid from the nozzle, the value is multiplied by a predetermined number of rotations, a unit cutting thickness, and the number of the injection nozzles, and the value is multiplied intermittently as a unit lifting interval. As described above, according to the configuration of the present invention, by using a high-pressure pump and an air compressor having the same injection conditions as those of the conventional method from each injection nozzle, the earth and sand having a plurality of unit cutting thicknesses are simultaneously cut. In addition to reducing the injection time, the amount of slime generated by construction can be reduced, resulting in a reduction in industrial waste, and a reduction in material costs by using solidified materials that match the design strength. It is characterized by improved workability and efficient and economical ground improvement.

[0005]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an injection pipe 2 having a triple structure according to the present invention, and an injection injection device 3 attached to the tip thereof to cut earth and sand within a predetermined formation range, and at the same time, injection of a cement-based solidifying material liquid from an injection nozzle to columnar consolidation. It is explanatory drawing which shows the construction aspect which constructs a body, drills while sending drilling water via the pouring swivel 1 to the formation start position of a predetermined formation area by the forming machine 4 beforehand, and makes the injection injection device 3 into a predetermined position. After fixation, 400 kg of fresh water is supplied as a high-pressure liquid through the injection swivel 1.
/ Cm ³ and discharge rate 140l / min, compressed air pressure 7kg
/ Cm ² at a discharge rate of 3.0 m ³ / min. Further, a cement-based solidifying material liquid as an injecting material was operated at a pressure of 30 kg / cm ² at a discharge rate of 240 l / min. The formation completion region 5 is formed by rotating the rotation in the range of 4 to 12 rotations. The injection / injection device 3 is provided with two injection nozzles 11, and the soil at the injection nozzle position is cut by high-pressure injection to form a soil / sand cutting area 6, and the cement-based solidifying material liquid injected from the injection nozzle 20 and After being stirred and mixed, the surplus is discharged as slime through the slime discharge path 7 to the ground. The unit lifting interval of the injection tube 2 is
As a result of intermittently raising the predetermined forming range with a spraying time of 30 seconds per time, the interval was 5 cm, which is a multiple of the unit cutting thickness 2.5 cm of the spray nozzle 11, and as a result, 2 m per 1 m of forming growth.
It is characterized by zero intermittent lifting and a 10 minute injection time, which can reduce the forming time by half. FIG. 2 is a cross-sectional view of the hole injection type injection injection device 3 used in the present invention.
There are a high-pressure flow path 8 communicating with the inner pipe of the injection pipe 2 having a triple structure, an air flow path 9 communicating with the middle pipe flow path, and an injection flow path 10 communicating with the outer pipe flow path. Two injection nozzles 11 are mounted in the direction opposite to each other at an interval equal to the unit cutting thickness in the vertical direction, and an injection nozzle 20 is provided below the injection nozzle 11. The injection nozzle 11 is composed of a combination of a high-pressure nozzle 14 communicating with the high-pressure channel 8 and an air nozzle 15 communicating with the air channel 9, and the air nozzle 15 is located at a position including the high-pressure nozzle 14. There is an air check valve 12 between the high pressure nozzle 14 and the high pressure check valve 13 and the air flow path 9 and the air nozzle 15, and an injection check valve between the injection flow path 10 and the injection nozzle 20. 21. FIG. 3 is a cross-sectional view of each check valve provided in the injection device 3.
FIG. 3 is a cross-sectional view showing a high-pressure liquid, which pushes up and discharges a stretchable annular valve 25 of a high-pressure check valve 13 from a high-pressure flow path 8 and is jetted from a high-pressure nozzle 14; FIG. 4 is a cross-sectional view, in which compressed air pushes up and discharges an elastic annular valve 25 of an air check valve 12 from an air passage 9 and discharges the air nozzle 1.
Inject from 5 FIG. 3C is a cross-sectional view showing the injection check valve 21, in which the injection material liquid pushes up the elastic annular valve 25 of the injection check valve 21 from the injection flow path 10 and discharges the injection liquid from the injection nozzle 20. It is characterized by.

[0006]

As described above, the effect of the structure of the present invention is that the injection / injection device at the tip of the injection pipe is provided by the conventional method in which the injection pipe is a multiple pipe having a plurality of flow paths such as a double pipe or a triple pipe. There is one injection nozzle for earth and sand cutting. Therefore, the injection pipe is intermittently rotated and pulled up at a pulling interval equal to the unit cutting thickness of the injection nozzle, and the predetermined formation area is solidified with a cement-based solidifying material liquid into a cylindrical shape. In the case of a conventional method using a triple pipe as an injection pipe, the injection conditions are as follows: the pressure of fresh water as a high pressure liquid is 400 kg / cm ² , the discharge rate is 70 l / min, and the pressure of compressed air is 7 kg / cm ² . Discharge rate 1.5m ³ /
Each pump is operated at a pressure of 40 kg / cm ² and a discharge rate of 180 l / min, and the unit lifting interval is equal to the unit cut thickness.
5 cm, intermittently rotating and pulling up at a rate of 30 seconds per unit pulling interval, and simultaneously forming a columnar consolidated body with a pile diameter of about 2 m by a cement-based solidifying material liquid injected from an injection nozzle. Minute injection time and 4
There is no intermittent lifting, 3.6c as solidified material
m is required cement solidifying material liquid amount of ^3, there is a further 5 m ³ or more slime emissions. According to the embodiment of the present invention, the capacity of each pump is increased to make clear water as a high pressure liquid a pressure of 400 k.
g / cm ² , discharge rate 140l / min and compressed air pressure 7k
By feeding at a discharge rate of 3.0 m ³ / min at g / cm ² and evenly jetting from the two injection nozzles, the two lifting intervals of the conventional method can be cut at the same time. It can be 2. Further, a cement-based solidifying material liquid was injected as an injecting material at a pressure of 30 kg / cm ² and the discharge amount was 2
By operating the pump at 40 l / min, the amount of cement-based solidifying material liquid of 2.4 m ^{3 and} the amount of slime discharge of 4 m ³ or more as the solidifying material were obtained, and the injection time was reduced by half compared to the conventional method per 1 m of growth. And about 30% solidified material and 20%
% Of the slime emission is achieved.
One of the most important technical management items in the high-pressure jet-stirring pile method, in which earth and sand is cut by a jet nozzle composed of a combination of a high-pressure nozzle and an air nozzle, is to prevent clogging of the slime, which can reduce the air effect. When the slime discharge route has the same shape, the greater the amount of slime discharged per unit time, the more effective the slime discharge is. In the case of the embodiment, the amount of slime discharged is 1.6 times that of the conventional method. And it can be reliably recovered from the slime discharge route. On the other hand, the injection / injection device according to the present invention has a check valve composed of a stretchable annular valve in all of the high-pressure nozzle and the air nozzle or the injection nozzle. Since the backflow of groundwater and earth and sand from each nozzle of the injection and injection device, which is a problem as a result of an increase in the number of times, can be reliably prevented, workability is improved, and in particular, compressed air is sent from one air passage to multiple air nozzles. Since the uniform injection is solved by the check valve using the elastic annular valve according to the present invention, it is possible to reliably form the columnar consolidated body with the cement-based solidifying material liquid even under a deep groundwater pressure. Can be done. According to the configuration of the present invention, by increasing the number of injection nozzles by increasing the capacity of the injection equipment and each pump as necessary, an efficient and economical high-pressure injection stirrer pile according to construction conditions The construction method can be implemented.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a construction mode of the present invention.

FIG. 2 is a cross-sectional view showing the injection / injection device of the present invention.

FIG. 3 is a sectional view showing a check valve in the injection device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Injection pipe swivel 2 Injection pipe 3 Injection injection device 4 Construction machine 5 Construction completion area 6 Sediment cutting area 7 Slime discharge path 8 High pressure flow path 9 Air flow path 10 Injection flow path 11 Injection nozzle 12 Air check valve 13 High pressure check Valve 14 High pressure nozzle 15 Air nozzle 16 High pressure differential valve 17 High pressure differential valve spring 18 Injection differential valve 19 Injection differential valve spring 20 Injection nozzle 21 Injection check valve 22 Drilling water discharge port 23 Drilling check valve 24 Drill bit 25 Elastic annular valve

Claims (4)

[Claims] 1. An injection pipe comprising a multi-tube comprising a plurality of flow paths,
A jet injection device is attached to the tip of the injection tube, and high-pressure liquid and compressed air are sent from the top of the injection tube via an injection tube swivel. The high-pressure liquid, the compressed air, and the injection material liquid are simultaneously injected as the liquid by injecting the cement-based solidifying material liquid and the compressed air, or the high-pressure liquid, the compressed air, and the injection material liquid are sent from the top of the injection pipe through the injection pipe swivel. While simultaneously injecting fresh water and compressed air as high-pressure liquid from the injection nozzle consisting of the combination of, the injection nozzle sprays cement-based solidification material liquid as the injection material liquid,
A high-pressure jet stirring pile for raising the injection pipe at a predetermined rotation speed and a lifting interval to cut earth and sand within a predetermined formation range, and simultaneously mixing and solidifying the predetermined formation range with a cement-based solidifying material liquid to form a columnar consolidated body. A high-pressure injection stir pile method, wherein the injection injection device is provided with at least two or more injection nozzles comprising a combination of a high-pressure nozzle and an air nozzle. 2. An injection and injection device attached to the tip of an injection pipe, the injection comprising a combination of a high-pressure nozzle communicating with a high-pressure flow path and an air nozzle containing the high-pressure nozzle and communicating with an air flow path. In the case of an injection / injection apparatus having an injection nozzle, there are at least two or more nozzles in the direction perpendicular to the axis of the injection / injection apparatus, and the injection nozzles are spaced at intervals equal to the unit cutting thickness. Is located below the injection nozzle, and in forming, the injection pipe is intermittently pulled up for a predetermined time as a unit pulling interval, which is a value obtained by multiplying a predetermined number of rotations, a unit cut thickness, and the number of the injection nozzles. And a high-pressure jet-stirring pile method according to claim 1. 3. An injection / injection apparatus comprising two or more injection nozzles each comprising a combination of a high pressure nozzle and an air nozzle, or comprising two or more injection nozzles each comprising a combination of a high pressure nozzle and an air nozzle. Below the injection nozzle is an injection injection device having an injection nozzle,
Between the high-pressure channel and high-pressure nozzle of the injection device and between the air channel and the air nozzle, or between the high-pressure channel and high-pressure nozzle of the injection device and between the air channel and the air nozzle, and further between the injection channel and the injection nozzle. A high-pressure jet-stirring pile method according to claim 1, wherein a check valve comprising an elastic annular valve is attached. 4. The check valve, comprising a stretchable annular valve, has a cylindrical shape with one of the ports being an inlet, and the end of the inlet is fixed by screwing or meshing with the outer periphery of the cylindrical face. There is a concave groove whose both surfaces are inclined surfaces, there are a plurality of discharge holes on the bottom surface of the concave groove, the concave groove is closed with a discharge hole, and an elastic annular valve is attached, from the inflow port 2. The high-pressure jet-stirred pile method according to claim 1, wherein the discharge hole has an outflow direction of 90 ° to 180 ° with respect to the inflow direction of the high-pressure injection stirrer.