JPH09111750A - High pressure jet agitation pile method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to develop a plurality of high pressure jet agitation piles simultaneously by combining one and more sub-injection holes whose developing areas are placed one upon another and then excavating the holes for one main injection hole and allowing slime to join and discharging the slime with a discharge pipe in the main injection hole. SOLUTION: The soil is excavated down to the lower end of a main injection hole scheduled developing area 8 with a casing pipe where the casing pipe is pulled and fixed above the scheduled developing area 8, thereby forming a slime discharge pipe 6. Then, a main injection hole jet injection device 7 is mounted on the tip of a main injection hole injection pipe 3 of a main injection hole machine 4, while excavation water is being supplied, the scheduled developing area 8 is excavated down to the lower end. In the same manner, a sub-injection hole scheduled developing area 8' is excavated with a sub-injection hole machine 4' down to the lower end. Then, the injection water is switched over to a cement-based solidifying liquid and compressed air, thereby turning the injection pipes 3 and 3' and mixing with the excavated soil and developing a cement-based solidifying pile in injection hole development areas 9 and 9'. The generated slime is joined in a doubled part of the injection hole development area 9 and 9' and discharging the slime to the ground from the clearance between the injection pipe 3 of the main injection hole and a slime discharge pipe 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a double pipe or a triple pipe as an injection pipe, and installs a high-pressure nozzle and an injection / injection device in which an air nozzle is combined around the injection pipe at its tip to cut a ground in a predetermined improvement range. However, the present invention relates to a high-pressure injection stirring pile construction method in which the ground is solidified into a column shape by mixing with a cement-based solidifying liquid.

[0002]

2. Description of the Related Art In a high-pressure injection stirring pile method consisting of a combination of a high-pressure injection fluid and compressed air, a double pipe is used as an injection pipe, and a high-pressure nozzle at the tip of the injection pipe and an injection nozzle having an air nozzle around the injection pipe are injected. A method of attaching a device and injecting a cement-based solidification liquid from a high-pressure nozzle in the injection injection device, and at the same time ejecting compressed air from an air nozzle around the high-pressure nozzle to cut the ground and mix and solidify with the cement-based solidification liquid. Alternatively, a triple pipe is used as an injection pipe, and there is an injection nozzle in which a high pressure nozzle and an air nozzle are combined around the injection pipe, and an injection injection device consisting of a cement-based solidified liquid nozzle separately attached below the injection nozzle is attached. , At the same time as injecting clean water from the high-pressure nozzle in the injection injection device, compressed air from the air nozzle around the high-pressure nozzle. Out was to cut the ground, and the cement solidifying liquid by jetting injection method or the like for solidification replace the cutting sand are known from cement solidifying liquid nozzle simultaneously. In both of the above two conventional methods, by injecting compressed air from the air nozzle by an injection nozzle that combines a high-pressure nozzle and an air nozzle around the high-pressure nozzle, the cement-based solidified liquid or fresh water in the ground water is injected from the high-pressure nozzle. As a result of suppressing the damping of the injection pressure of, the common principle is that the principle of dramatically expanding the earth and sand cutting range in the ground compared to the case of using a high-pressure nozzle alone is applied. In the conventional method, the discharge amount of the cement-based solidifying liquid is about 60 liters per minute, and as a result, the discharge amount of slime generated during construction is small at about 60 liters per minute, and the discharge route is clogged with cutting soil. Is easily blocked. If slime blockage occurs during construction of the high-pressure jet stirring pile method, the surrounding ground uplift,
Alternatively, adverse effects such as influences on surrounding structures cannot be avoided, and in this respect, the conventional method using the double pipe has a problem. On the other hand, in the conventional method using the triple pipe, the casing pipe is first drilled to the lower end of the predetermined improvement range, the triple pipe with the injection injection device is inserted into the casing pipe, and then the casing pipe is pulled up to an arbitrary position and fixed. By using the casing pipe as a slime discharge pipe, the discharge route can be surely secured, and the discharge amount of slime is as high as about 250 liters per minute from the discharge amount of the cement-based solidifying liquid and the fresh water, so that the slime is blocked. It can be said that it is a highly reliable construction method without any harmful effects. However, when comparing the amount of cement-based solidified liquid per unit building growth and the amount of slime discharged, the cost is higher than that of the conventional method using double pipes, and the material cost and slime disposal cost are correspondingly large, which is economical and economical. There was a problem in terms of environmental protection. For the above reasons, at present, the double pipe method is used when the soft ground is relatively shallow and the triple pipe method is often used when the ground is deep and hard.

[0003]

SUMMARY OF THE INVENTION The present invention eliminates the problem of the conventional method using a double pipe as an injection pipe, that is, the protrusion of the ground, or the clogging of slime that causes an influence on surrounding structures, thereby ensuring a reliable operation. A economical and high-pressure injection stirring pile method is proposed.

[0004]

The structure of the present invention for solving the above-mentioned problems is to arrange at least two or more injection holes in the construction of a pile in a predetermined improvement range, and to arrange the plurality of said injection holes. With respect to one main injection hole, at least one or more injection holes at positions where the main injection hole and the formation region overlap are combined as a sub injection hole with respect to one main injection hole, and the main injection hole and the sub injection hole combined are: It is characterized in that the injection device including the injection pipe and the injection injection device is inserted or drilled up to the lower end of the predetermined improvement range in advance, and then the combined main injection hole and sub injection hole are simultaneously formed. Also, in the creation of the combined main injection hole and sub injection hole,
At the position of the main injection hole, there is a slime discharge pipe that contains the injection device for the main injection hole.The slime discharge pipe is drilled in advance to the lower end of the prescribed improvement range with a casing pipe, etc., and the injection device for the main injection hole is inserted. Then, the casing pipe is pulled up to a predetermined position and fixed to form a slime discharge pipe.
Alternatively, there is a slime discharge pipe at the position where the combined main injection hole and sub injection hole creation areas overlap, and at the same distance from the combined main injection hole and sub injection hole, and the slime discharge pipe is predetermined by a casing pipe or the like. After drilling to the lower end of the improvement range, pull up and fix it to a predetermined position to make a slime discharge pipe. In the practice of the present invention having the above-described configuration, the slime continuously generated from each of the main injection hole and the sub injection hole, which are combined at the time of forming the predetermined improvement range, is the slime discharge pipe at the position including the main injection pipe. Or from the slime discharge pipe at the position where the combined main injection hole and the auxiliary injection hole overlap, and at the same distance from the combined main injection hole and the auxiliary injection hole, through the overlapping part of the injection area. Combined and discharged through the slime discharge pipe to the ground. For example, when one main injection hole and one sub injection hole are combined, the main injection hole or the combined main injection hole and sub injection hole is equal when the combined main injection hole and sub injection hole are formed. From the slime discharge pipe located at a distance, double the amount of slime generated during the conventional method is merged and discharged through the overlapping part of the construction area, resulting in slime discharge under the same discharge path diameter conditions. The speed is double that of the conventional one, and the discharge path is secured by the slime discharge pipe, so the slime can be discharged reliably without being blocked.

[0005]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a case where the present invention is carried out by a method of using a double pipe as an injection pipe, and a drilling machine is used in advance at the position of the main injection hole, and the lower end of the planned main injection hole forming region 8 is formed by a casing pipe. After drilling up to the upper position that does not overlap the creation area, it is fixedly fixed and installed as a slime discharge pipe 6, then the main injection hole machine 4 is installed again at the main injection hole position, the main injection hole injection pipe 3 and its tip. The main injection hole injection injection device 7 is attached to the main injection hole injection pipe swivel 1 and the main injection hole injection hose 2.
While sending the drilling water from, the drilling is performed to the lower end of the planned main injection hole forming area 8. Similarly, a sub-injection hole machine 4'is installed at the sub-injection hole position, a sub-injection hole injection pipe 3'and a sub-injection hole jetting and injecting device 7'are attached to the tip of the sub-injection hole injection pipe swivel 1 '. Then, while drilling water is fed from the sub-injection hole injecting hose 2 ', the sub-injection hole is drilled up to the lower end of the planned sub-injection hole forming region 8'. The combined main injection hole and sub injection hole are formed by sending the cement-based solidifying liquid and compressed air from the main injection hole injection hose 2 and the sub injection hole injection hose 2 to inject the main injection hole injection injection device 7 and the auxiliary injection hole injection. The main injection hole injection pipe 3 and the auxiliary injection hole injection pipe 3'are rotated at a predetermined number of revolutions simultaneously with the injection from the injection nozzle in the injection device 7 ', so that the main injection hole formation region 9 and the sub injection hole formation region 9 are formed. 'Is mixed with the cutting soil and the cement-based solidifying solution to form the cement-based consolidated pile. Simultaneously with the start of formation, the slime generated from each of the combined main injection hole and sub injection hole merges at the overlapping portion of the main injection hole formation area 9 and the sub injection hole formation area 9 ', and the slime discharged from the main injection hole is discharged. After passing through the route 10, the slime discharge pipe 6
And the main injection hole of the main injection hole is discharged to the above-ground portion from the gap and is sequentially processed by the discharge pump while being stored in the slime pit 5.

[0006]

According to the conventional method using the double pipe, the hole diameter is 8
The diameter of the injection pipe is 5 mm and the diameter of the injection pipe is 60 mm as a standard. The cement-based solidification liquid is injected at a discharge rate of 60 liters per minute, and as a result, the slime passing through the slime discharge route in the injection hole is 16 minutes per minute. Discharge to the ground at a speed of 0.6m. According to the present invention, when the slime discharge pipe diameter is set to 85 mm under the same conditions as described above, the generated slime is merged into the common slime discharge pipe, and as a result, the discharge speed is doubled to 33.2 m / min. Will be. In addition, when the cement-based solidified liquid is jetted from the high-pressure nozzle and compressed air is jetted from the air nozzles around the high-pressure nozzle to cut the ground, the properties of the slime generated depending on the nature of the ground in the created area also change. Is known to
In sandy soil, the constituent soil particles are decomposed and mixed with cement-based solidifying liquid to form mortar, which can be discharged relatively easily, but in the case of cohesive soil, the constituent soil particles themselves are decomposed. As a result, the slime becomes highly viscous and contains a residual clod of decomposed cohesive soil, so the faster the slime discharge speed, the easier the decomposed clod is discharged to the ground. The amount of residual soil mixed in the development area is reduced, and the effect of uniforming the improved strength in the development area is also obtained. Further, in the conventional method using a double pipe or a triple pipe as an injection pipe, it is necessary to previously install a slime pit for slime treatment on the construction base surface in a range including the entire area of the arranged injection holes. According to the method, the size of the slime pit required may be within the range including the arranged slime discharge pipes, and the area thereof can be halved as compared with the conventional method.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a plan view in which a slime discharge pipe is arranged at a main injection hole position of the present invention.

FIG. 3 is a plan view in which a slime discharge pipe is arranged at an equal distance from the combined main injection hole and sub injection hole of the present invention.

[Explanation of symbols]

 1 Main injection hole injection pipe swivel 1'Sub injection hole injection pipe swivel 2 Main injection hole injection hose 2'Sub injection hole injection hose 3 Main injection hole injection pipe 3'Sub injection hole injection pipe 4 Main injection hole machine 4'Sub injection Hole machine 5 Slime pit 6 Slime discharge pipe 7 Main injection hole injection injection device 7'Sub injection hole injection injection device 8 Main injection hole planned creation area 8'Sub injection hole planned creation area 9 Main injection hole creation area 9'Sub injection hole Creation area 10 slime discharge route

Claims (2)

[Claims] 1. A double pipe or a triple pipe is used as an injection pipe, and an injection injection device having an injection nozzle in which a high pressure nozzle and an air nozzle are combined around the high pressure nozzle is attached to the tip of the injection pipe, and the injection pipe has a predetermined rotation speed. While rotating with, the soil in the specified improvement range is cut by simultaneously injecting the cement-based solidifying liquid from the high-pressure nozzle and the compressed air from the air nozzle, and solidifying it into a columnar shape with the injected cement-based solidifying liquid. In the construction of the pile in the predetermined improvement range, which is a high-pressure injection stirring pile construction method, at least two or more injection holes are arranged, and the arranged injection holes are one main injection hole. On the other hand, at least one or more injection holes at positions where the main injection hole and the formation area overlap are combined as a sub injection hole, and the piles of the combined main injection hole and sub injection hole are simultaneously formed. High-pressure injection stirring pile method. 2. The construction according to claim 1, wherein the main injection hole has a slime discharge pipe including the injection pipe, or the main injection hole and the auxiliary injection hole are overlapped with each other and the main injection hole is formed. There is a slime discharge pipe at the same distance from the auxiliary injection hole,
When forming the combined main injection hole and sub injection hole, the slime generated from each of the combined main injection hole and sub injection hole is merged into the slime discharge pipe and discharged, and the combined slime holes are formed simultaneously. A high-pressure jet agitation pile method characterized by using a discharge pipe.