JP2017002464A - Method and device for checking improvement radius of improvement body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for checking whether or not improvement radius of an improvement body during establishment in a high-pressure injection mixing method has reached a designed improvement radius during establishment of the improvement body.SOLUTION: An arrival pipe 5, which is a cylindrical steel pipe, is inserted in a ground 6 in advance at a position B at a distance L corresponding to a designed improvement radius from a position A where an injection pipe 4 is inserted in the ground 6 before the injection pipe 4 is inserted into the ground 6. Subsequently, the injection pipe 4 is inserted into the ground 6 by lowering the pipe downward while rotating the pipe. When the injection pipe 4 reached a predetermined depth, lowering of the injection pipe 4 is stopped. A solidification material slurry is injected from a nozzle 9 while the injection pipe 4 is pulled up at a predetermined speed while the injection pipe 4 is rotated at predetermined revolution speed. An acceleration sensor 10 detects acceleration generated on the arrival pipe 5 and transfers the detection result to a recording meter 11 while the injection pipe 4 is pulled up.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method and an apparatus for confirming an improved radius of an improved body, and more particularly, to a method and an apparatus for confirming an improved radius of an improved body formed in the ground by high-pressure jet agitation.

  In the high-pressure jet agitation method, the solidified material slurry, which has been pressurized by an ultra-high pressure pump, is cut from the ground by the energy that is injected from the nozzle provided at the tip of the rod, and an improved body is created in the ground. It is a construction method. However, since the improved body is created in the ground, the improved body itself cannot be visually observed. Therefore, unless the improved body is excavated and exposed, the improved radius of the improved body cannot be directly measured.

  Patent Document 1 describes a method for determining an improved radius during creation of an improved body. In this method, a built-in pipe is fixed in each vertical hole provided at a plurality of points at different distances from the injection pipe, a detector is provided in each built-in pipe, and then the solidified material slurry is injected from the injection nozzle of the injection pipe. The high-pressure jet is injected and the sound generated when the injected solidifying material slurry collides with the built-in pipe or the vibration of the built-in pipe is detected by the detector to determine which built-in pipe the solidifying material slurry has reached. By judging, the improvement radius of the improvement body under construction is judged.

Japanese Patent No. 5542593

  However, in the method described in Patent Document 1, it is necessary to provide a detector in the built-in pipe. Then, it is necessary to prepare a built-in pipe having an inner diameter that can accommodate the detector, and there is a problem that a built-in pipe corresponding to the configuration of the detector must be prepared.

  The present invention has been made to solve such problems, and it is confirmed during the creation of the improved body whether or not the improved radius of the improved body under the high-pressure jet stirring method has reached the design improved radius. It is an object to provide a method and apparatus.

In the method of cutting the ground by injecting the solidified material slurry into the ground and mixing and stirring the solidified material slurry and the soil to be improved to create the improved body and confirming the improved radius of the improved body, the solidified material slurry is injected. A step of providing one or more access pipes to be inserted into the ground at a position separated by a preset design improvement radius from a position at which an injection pipe having a nozzle is inserted into the ground; A step of providing a detector for detecting the acceleration generated in the arrival pipe, a step of injecting the solidified material slurry from the nozzle while the injection pipe is inserted into the ground and then pulling up while rotating the injection pipe, and while the injection pipe is pulled up, A step of detecting the acceleration generated in the access pipe, and a step of determining whether or not the improvement radius of the improvement body under construction has reached the design improvement radius based on the detected acceleration. Including the door.
If it is determined that the improvement radius of the improvement body under construction has not reached the design improvement radius, the injection of the solidified slurry and the pull-up of the injection pipe are stopped, and then the injection pipe is inserted into the ground again and injected. The step of injecting solidified material slurry from the nozzle while pulling up the tube, the step of detecting the acceleration of the arrival tube while pulling up the injection tube, and the improvement radius of the improvement body being built based on the detected acceleration are designed and improved And determining whether or not the radius has been reached.
The detector detects acceleration at a constant detection time interval, and the constant detection time interval is an interval less than t represented by t = 30B / [π · (r + B / 2) · a], where , B [m] is the width [m] of the arrival tube when the arrival tube is viewed from the injection tube, r [m] is the distance from the injection tube to the arrival tube, and a [rpm] is the injection tube It may be the number of rotations.
Providing at least one other access pipe in addition to the position where the injection pipe having the nozzle into which the solidifying material slurry is injected is inserted into the ground by a predetermined design improvement radius; and at least one Providing another detector tube with a detector for detecting an acceleration generated in at least one of the other access tubes.
The detector may be detachably fixed at a position above the ground of the arrival tube or another arrival tube.

The device that checks the radius of improvement of the improved body while injecting the solidified material slurry into the ground to cut the ground and mixing and stirring the solidified material slurry and the soil to be improved while checking the improved radius of the improved body. One or a plurality of arrival tubes provided to be inserted into the ground at a position separated by a predetermined design improvement radius from the position at which the injection tube having the nozzle is inserted into the ground, and acceleration generated in the arrival tube And a recorder for recording the acceleration detected by the detector.
At least one other access pipe provided to be inserted into the ground at a position other than the position where the injection pipe having the nozzle into which the solidifying material slurry is injected is inserted into the ground at a predetermined design improvement radius. And a detector for detecting an acceleration generated in the at least one other reaching tube in the at least one other reaching tube.
The access tube may be the same tubular member as the injection tube.
The detector may be detachably fixed at a position above the ground of the arrival tube or another arrival tube.

  According to this invention, while the solidifying material slurry is ejected from the nozzle while pulling up the injection pipe, the acceleration generated in the arrival pipe provided at a position corresponding to the design improvement radius from the injection pipe is detected and detected. Based on the measured acceleration, it is determined whether or not the improvement radius of the improvement body being built has reached the design improvement radius. Can be confirmed inside.

1 is an overall view of a high-pressure jet stirring apparatus used in a method according to an embodiment of the present invention. It is a figure which shows the recording of the acceleration detected in the method which concerns on this embodiment. In the method which concerns on this embodiment, it is the figure which simplified and showed arrangement | positioning of the injection | pouring pipe | tube and an arrival pipe | tube.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows an overall view of a high-pressure jet stirring apparatus used in this embodiment. FIG. 1 shows a high-pressure jet stirring device 1 placed on the ground 6 to be improved. The high-pressure jet agitating apparatus 1 includes an injection tube 4 that can be inserted into the ground 6. The injection tube 4 is movable in the vertical direction while rotating. One end of the injection tube 4 is connected to one end of the hose 7 via the swivel 3. The other end of the hose 7 is connected to a plant (not shown) that prepares and pumps the solidified slurry. At the other end of the injection tube 4, a nozzle 9 for injecting the solidifying material slurry is provided. The nozzle 9 communicates with the hose 7 via a slurry flow path (not shown) formed in the injection tube 4.

  From the position A at which the injection pipe 4 is inserted into the ground 6 to the position B separated by an arbitrary distance L, the ground pipe 6 is parallel to the injection pipe 4 so that the arrival pipe 5, which is an iron pipe having a cylindrical shape, is parallel to the injection pipe 4. Has been inserted. As shown in FIG. 1, an acceleration sensor 10, which is a detector that detects acceleration generated in the reaching pipe 5, is detachably attached to the reaching pipe 5 by a fixing means such as a magnet (not shown). Is attached. The acceleration sensor 10 may be fixed to the arrival tube 5 at a position where the acceleration sensor 10 can continuously measure the acceleration generated in the arrival tube 5 during construction. Installed in the vicinity. The acceleration sensor 10 is electrically connected to a recorder 11 that records the detected acceleration. The distance L corresponds to a design improvement radius set in advance as an improvement radius of the improvement body 8 formed by spraying the solidified material slurry in the ground.

Next, the operation of the high-pressure jet stirring method according to this embodiment will be described.
As shown in FIG. 1, the high-pressure jet agitator 1 is installed on the ground 6 to be improved, and the injection pipe 4 is lowered while being inserted and inserted into the ground 6. When the injection tube 4 is inserted to a predetermined depth, the lowering of the injection tube 4 is stopped. When the solidified material slurry is pumped at a high pressure from a plant (not shown) through the hose 7, the solidified material slurry passes through a slurry flow path (not shown) formed in the injection pipe 4 and is then injected from the nozzle 9. When the injection tube 4 is pulled up at a predetermined speed while rotating the injection tube 4 at a predetermined number of revolutions, the ground is cut by the injected solidifying material slurry, and the solidifying material slurry and the soil to be improved are mixed and agitated. A substantially cylindrical improvement body 8 is formed therein.

  The improved radius of the improved body 8 formed at this time is the distance from the nozzle 9 to the position where the injected solidified material slurry reaches. The position where the solidified material slurry reaches is influenced not only by the injection pressure of the solidified material slurry but also by the hardness (shear strength) of the ground to be cut. Since the hardness (shear strength) of the ground cannot be ascertained before construction, there is a possibility that the improvement radius of the improved body to be created does not satisfy the design improvement radius.

  Therefore, in this embodiment, before the injection tube 4 is inserted into the ground 6, the cylinder is placed at a position B separated from the position A where the injection tube 4 is inserted into the ground 6 by a distance L corresponding to the design improvement radius. A reach pipe 5 which is an iron pipe having a shape is inserted in the ground 6 in advance. While pulling up the injection tube 4, the acceleration sensor 10 attached to the arrival tube 5 detects the acceleration generated in the arrival tube 5 and transmits the detection result to the recorder 11. When the solidified material slurry sprayed from the nozzle 9 does not reach the arrival tube 5, the solidification material slurry does not vibrate the arrival tube 5, but when the solidification material slurry reaches the arrival tube 5, the solidification material slurry. Vibrates the access tube 5.

  Then, as shown in FIG. 2, the detected arrival is more when the solidified material slurry reaches the reaching tube 5 than when the solidified material slurry injected from the nozzle 9 does not reach the reaching tube 5. The acceleration of the tube 5 increases, and the peak of the acceleration recorded on the chart 12 in the recorder 11 is larger in the latter than in the former. Thereby, it is possible to determine whether or not the improvement radius of the improvement body 8 has reached the design improvement radius during the creation of the improvement body 8. In order to clarify the acceleration peak in the former case, it is desirable to detect the acceleration of the arrival pipe 5 before the start of the injection of the solidified slurry from the nozzle 9.

  When it is determined that the improvement radius of the improvement body 8 has not reached the design improvement radius during the formation of the improvement body 8, the injection of the solidified material slurry from the nozzle 9 and the lifting of the injection pipe 4 are stopped, and the injection pipe 4 is inserted again to the position where the pulling-up starts or the improved radius of the improved body 8 does not reach the design improved radius. Then, the pulling-up speed of the injection tube 4 is reduced, and the solidifying material slurry is ejected from the nozzle 9 and the injection tube 4 is pulled up. Also in this case, it is determined by the same method whether or not the improvement radius of the improvement body 8 has reached the design improvement radius. The reason why the pulling-up speed of the injection tube 4 is decreased is to increase the improved radius of the improved body 8. Other methods include increasing the injection pressure of the solidifying material slurry or increasing the injection flow rate of the solidifying material slurry by changing the nozzle tip of the nozzle 9 if the solidifying material slurry pump has sufficient capacity. Also good. Further, prior drilling may be performed to disturb the improvement target range, and the shear strength of the improvement target ground may be lowered prior to the re-injection of the solidified slurry.

  In this way, while the solidifying material slurry is ejected from the nozzle 9 while pulling up the injection pipe 4, the acceleration generated in the arrival pipe 5 provided at a position separated from the injection pipe 4 by a distance L corresponding to the design improvement radius is detected. Based on the detected acceleration, it is determined whether or not the improvement radius of the improvement body 8 under construction has reached the design improvement radius by determining whether or not the improvement radius of the improvement body 8 under construction has reached the design improvement radius. Can be confirmed during the construction of the improved body 8.

  In this embodiment, a single-tube high-pressure jet stirring method in which only the solidified material slurry is jetted from the nozzle 9 formed in the injection pipe 4 is performed, but the present invention is not limited to this mode. The injection tube 4 has a double tube structure, and can be applied to a double tube method in which air is injected together with the solidified material slurry so as to surround the solidified material slurry. Furthermore, the injection tube 4 can also be applied to a multiple tube construction method such as a triple tube structure.

  In this embodiment, the reach pipe 5 is an iron pipe having a cylindrical shape, but is not limited to this form. The reach pipe 5 may be any iron rod-shaped one, round steel bar, H steel, or the like having a characteristic capable of detecting vibration generated when the injected solidified material slurry hits the reach pipe 5 as acceleration. It may be a thing. Therefore, if the same thing as the tubular member which comprises the injection | pouring pipe | tube 4 is used as the arrival pipe | tube 5, the preparation of the method and apparatus which concern on this invention can be simplified.

  In this embodiment, only one access pipe 5 is provided, but this is not a limitation. A plurality of reaching pipes 5 may be provided at positions separated from the position where the injection pipe 4 is inserted into the ground 6 by a preset design improvement radius. Furthermore, in addition to the position where the injection tube 4 is inserted into the ground 6 away from the position where the design improvement radius is set in advance, one or a plurality of other arrival tubes having different distances from the injection tube 4 are provided. Thus, the range of the improved radius of the improved body 8 can be confirmed. In addition, it is necessary to provide a similar acceleration sensor in another reaching tube in the same manner as the case where the acceleration sensor 10 is provided in the reaching tube 5 to detect acceleration generated in another reaching tube.

  When the acceleration sensor 10 that detects the acceleration generated in the arrival pipe 5 detects intermittently at a constant detection time interval, depending on the detection time interval, it corresponds to the case where the solidified material slurry hits the arrival pipe 5. As shown in FIG. 2, it cannot be clearly distinguished from the case of not. FIG. 3 shows a simplified arrangement of the injection tube 4 and the arrival tube 5. In FIG. 3, the diameter of the reaching tube 5 is B [m], and the distance from the center of the injection tube 4 to the reaching tube 5 is r [m]. When the line segment L having a length (r + B / 2) rotates around the injection tube 4, the end of the line segment L draws a locus of the circle S. When the diameter of the circle S is much larger than the diameter of the reaching tube 5, the solidified material slurry injected from the nozzle 9 (see FIG. 1) of the injection tube 4 vibrates the reaching tube 5 because the solidifying material slurry Can be thought of as passing through a portion of the length B of the locus of the circle S. Then, in FIG. 3, when the end of the line segment L passes the portion of the length B in the middle of drawing the trajectory of the circle S, it is when the solidifying material slurry hits the arrival tube 5 and vibrates the arrival tube 5. Can think.

Here, when the time when the end of the line segment L passes through the length B portion is t, t is expressed by the following equation (1).
t = B / (r + B / 2) ω (1)
However, ω [rad / sec] is an angular velocity when the line segment L rotates around the injection tube 4, and this schematically represents the angular velocity of the rotation of the injection tube 4. Here, if the rotation speed of the injection tube 4 is a [rpm],
ω = 2πa / 60 [sec] = πa / 30 (2)
Substituting Equation (2) into Equation (1) t = 30B / [π · (r + B / 2) · a] (3)
It becomes.

  If the detection time interval of the acceleration sensor 10 (see FIG. 1) is set to a value smaller than t obtained from the above equation (3), the solidifying material slurry has a length B even if the rotational speed a is uneven. At least once during the passage of the part, it is possible to detect the acceleration that occurs when the jet of solidified material slurry hits the access tube 5 directly. Then, during one rotation of the injection tube 4, the acceleration of the reaching tube 5 due to the vibration generated when the jet of solidified material slurry directly hits the reaching tube 5 can be detected at least once. As a result, as shown in FIG. 2, the acceleration peak becomes clear so that the case where the solidified material slurry hits the reaching pipe 5 and the case where it does not hit can be distinguished.

  In the above description, since the reaching tube 5 has a cylindrical shape, the length B is the diameter of the reaching tube 5. However, when the reaching tube 5 has a shape other than the cylindrical shape and the columnar shape, the injection tube 4 is used. The width of the arrival tube 5 when the arrival tube 5 is viewed from the side, that is, the length of the longest portion of the arrival tube 5 in the direction perpendicular to the length direction of the arrival tube 5 may be defined as B.

  As described above, the case where the jet jet jetted mainly at high pressure is the solidified slurry, but the jet jet of the solidified slurry is also used when the jet jet cutting the ground by the triple pipe method or the like is ultra high pressure drilling water. Needless to say, the concept in which is replaced with a jet jet of ultrahigh-pressure drilling water is applied and included in the knowledge of the present invention.

  4 injection pipe, 5 reaching pipe, 6 ground, 8 improved body, 9 nozzles, 10 acceleration sensor (detector), 11 recorder.

Claims (9)

A method of confirming the improved radius of the improved body while injecting the solidified material slurry into the ground to cut the ground and mixing and stirring the solidified material slurry and the improvement target soil,
A step of providing one or a plurality of reaching pipes in the ground at a position separated by a predetermined design improvement radius from a position at which the injection pipe having a nozzle for injecting the solidifying material slurry is inserted into the ground; When,
Providing the access tube with a detector for detecting acceleration generated in the access tube;
After inserting the injection tube into the ground, injecting the solidified material slurry from the nozzle while pulling up while rotating the injection tube;
Detecting the acceleration generated in the access tube while the injection tube is pulled up;
Determining whether the improvement radius of the improvement body being built has reached the design improvement radius based on the sensed acceleration. When it is determined that the improvement radius of the improvement body under construction does not reach the design improvement radius, after stopping the injection of the solidified slurry and the pulling up of the injection pipe,
Inserting the injection tube into the ground again and injecting the solidified material slurry from the nozzle while pulling up the injection tube;
Detecting the acceleration of the reach tube while pulling up the injection tube;
The method according to claim 1, further comprising: determining whether the improvement radius of the improvement body being built has reached the design improvement radius based on the detected acceleration. The detector detects the acceleration at a fixed detection time interval, and the fixed detection time interval is:
t = 30B / [π · (r + B / 2) · a]
An interval less than t expressed by
Here, B [m] is the width [m] of the arrival tube when the arrival tube is viewed from the injection tube, r [m] is the distance from the injection tube to the arrival tube, and a The method according to claim 1 or 2, wherein [rpm] is the number of rotations of the injection tube. Providing at least one other reaching pipe in addition to a position away from a position where the injection pipe having the nozzle through which the solidifying material slurry is injected is inserted into the ground by a preset design improvement radius;
The method according to any one of claims 1 to 3, further comprising the step of providing the at least one other access tube with a detector that detects an acceleration generated in the at least one other access tube.   The method according to any one of claims 1 to 4, wherein the detector is detachably fixed at a position above the ground of the reaching pipe or the other reaching pipe. A device for confirming the improved radius of the improved body while jetting the solidified material slurry into the ground to cut the ground and mixing and stirring the solidified material slurry and the soil to be improved while forming the improved body,
One or a plurality of reaching pipes provided to be inserted into the ground at a position separated from a position where the injection pipe having the nozzle for injecting the solidifying material slurry is inserted into the ground by a predetermined design improvement radius. When,
A detector for detecting acceleration generated in the access pipe;
And a recorder for recording the acceleration detected by the detector. At least one other arrival provided to be inserted into the ground at a position other than the position where the injection pipe having the nozzle through which the solidifying material slurry is injected is inserted into the ground at a predetermined design improvement radius. Tube,
The apparatus according to claim 6, further comprising a detector for detecting an acceleration generated in the at least one other access tube in the at least one other access tube.   The device according to claim 6 or 7, wherein the access tube is the same tubular member as the injection tube.   The device according to any one of claims 6 to 8, wherein the detector is detachably fixed at a position above the ground of the reaching tube or the other reaching tube.

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