JP2015001121A - Ground improvement device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ground improvement device and a method, capable of construction even at a job site severe in height restriction, and capable of stably vertically moving a treatment machine having an agitation blade in the ground.SOLUTION: A treatment machine 2 of downwardly projecting a rotary shaft 4 for rotatingly driving by installing an agitation blade 5, is connected to a suspension wire 10c wound on a drum 10a of a winch 10, and the suspension wire 10c is delivered by operating the winch 10, and after excavating the ground B up to the predetermined depth by downwardly moving the treatment machine 2 by controlling an attitude of the treatment machine 2 by a stabilizer 6 installed in the treatment machine 2, the suspension wire 10c is wound by operating the winch 10 while rotatingly driving the agitation blade 5 while supplying a ground improvement chemical S in its ground B via a supply line 8, and ground improvement is executed by agitating and mixing the ground improvement chemical S in the ground B by upwardly moving the treatment machine 2 by controlling the attitude of the treatment machine 2 by the stabilizer 6.

Description

  The present invention relates to a ground improvement device and method, and more particularly, can be applied even at a site where the height is severely restricted, and can stably move a processing machine equipped with a stirring blade up and down in the ground. The present invention relates to a ground improvement device and method.

  There is known a CDM (Cement Deep Mixing) method for improving a soft ground to a solid ground by stirring and mixing soft soil and an improved material. In the CDM method, a ground improvement device provided with a stirring blade that is rotationally driven is used (see, for example, Patent Document 1). This stirring blade is attached to a long rod and moves up and down in the ground. As a construction process, first, the ground is excavated to a predetermined depth by moving downward in the ground while rotating the stirring blade. Thereafter, while supplying the ground improvement chemical solution into the ground, the stirring blade is rotated and moved upward. As a result, the ground improvement chemical solution is diffused and mixed in the ground to improve the ground.

  Here, since the stirring blade is attached to the long rod, the conventional ground improvement device for performing the CDM method has been provided with a rod for supporting the long rod. For this reason, there are problems such as limited work time at construction sites where height restrictions are severe, such as in the vicinity of airports. On the other hand, since the stirring blade is attached to the rod, it can move up and down stably without being greatly shaken in the ground. Therefore, when there are no rods and wrinkles, it becomes difficult to move the stirring blades up and down stably in the ground.

JP 2007-224645 A

  An object of the present invention is to provide a ground improvement device and method that can be applied even on a site with severe height restrictions and can stably move a processing machine equipped with a stirring blade up and down in the ground. It is in.

  In order to achieve the above object, the ground improvement device of the present invention is a ground improvement device comprising a processing machine having a stirring blade that moves up and down in the ground, and a supply line that supplies a ground improvement chemical into the ground. A rotary shaft, which is attached to a blade and is driven to rotate, protrudes downward from the processing machine, and a winch that moves the processing machine up and down via a suspension wire, and is attached to the processing machine to control the attitude of the processing machine. It is provided with a stabilizer.

  In the ground improvement method of the present invention, the agitating blade is rotated and moved downward in the ground to excavate the ground to a predetermined depth, and during or after the excavation, the ground improving chemical solution is supplied into the ground, In the ground improvement method in which the ground improvement chemical solution is stirred and mixed in the ground by rotating and rotating, and a rotating shaft that is rotationally driven with the agitating blade attached is projected downward. When the excavator is excavated to a predetermined depth by rotating the stirring blade in the ground and rotating it, the winch is activated. The suspension wire is fed out, the attitude of the processor is controlled by a stabilizer attached to the processor, the processor is moved downward, and the stirring blade is rotated and moved upward. When the ground improvement chemical solution is stirred and mixed in the ground, the winch is operated to wind up the suspension wire, and the processing machine is moved upward by controlling the attitude of the processing machine by the stabilizer. And

  According to the present invention, a processing machine is used in which a rotating shaft that is attached with a stirring blade and is driven to rotate is protruded downward. Then, this processing machine is connected to a suspension wire wound around a winch. When the processing machine is moved downward in the ground, the suspension wire is unwound from the winch, and when moved upward, the suspension wire is wound around the winch. . Therefore, unlike the prior art, it is not necessary to attach the stirring blade to the long rod, and accordingly, no soot is required. Therefore, it is possible to perform construction even at a site where height restrictions are severe.

  Moreover, since the stabilizer is attached to the processing machine, when the processing machine moves up and down in the ground, the processing machine can be controlled to an appropriate posture by the stabilizer. Thereby, the processing machine can be moved up and down stably in the ground.

It is explanatory drawing which illustrates the whole outline | summary of embodiment of the ground improvement apparatus of this invention. FIG. 2 is a partially enlarged view of FIG. 1. It is explanatory drawing which illustrates the state which the processing machine of FIG. 2 has closed the stabilizer. It is A arrow directional view of FIG. FIG. 4 is a view taken in the direction of arrow B in FIG. It is a top view which expands and illustrates a rotary blade. It is explanatory drawing which illustrates the state which the processing machine of FIG. 2 has opened the stabilizer. It is C arrow line view of FIG. It is explanatory drawing which illustrates the state which set the processing machine on the ground. It is explanatory drawing which illustrates the process of moving a processing machine below in the ground to the vicinity of the lower end part area | region of the ground improvement object range. It is explanatory drawing which illustrates the process of moving a processing machine downward in the lower end part area | region of the ground improvement object range. It is explanatory drawing which illustrates the process of moving a processing machine upward in the lower end part area | region of the ground improvement object range. It is explanatory drawing which illustrates the process of moving a processing machine downward again in the lower end part area | region of the ground improvement object range. It is explanatory drawing which illustrates the process of moving a processing machine upward again in the ground improvement object range. It is explanatory drawing which illustrates the state which pulled up the processing machine from the ground and the ground was improved.

  Hereinafter, the ground improvement device and method of the present invention will be described based on an embodiment in the case of improving the bottom of the ground.

  A ground improvement device 1 of the present invention illustrated in FIGS. 1 to 5 is a device that improves the ground by a deep mixing method, and is installed on a work boat 13. The ground improvement device 1 includes a processing machine 2 having a stirring blade 5, a winch 10 for moving the processing machine 2 up and down via a suspension wire 10c, a stabilizer 6 attached to the processing machine 2, and a ground improvement in the ground. And a supply line 8 for supplying the chemical S.

  The stirring blades 5 are attached to the respective rotary shafts 4 projecting downward from the processing machine 2 in two upper and lower stages. The number of stages of the stirring blades 5 can be one, three, or the like. The number of rotating shafts 4 is not limited to four, and can be set to an appropriate number, but a plurality is preferable.

  The number of stirring blades 5 extending in the horizontal direction at each stage of the single rotating shaft 4 is two in this embodiment, but may be one, three, or the like. In the case where a plurality of stirring blades 5 are provided at each stage of the single rotating shaft 4, they may be arranged at equal intervals in the circumferential direction. In this embodiment, two stirrer blades 5 are arranged at positions facing each other (positions separated by 180 ° in the circumferential direction).

  The rotating shaft 4 (stirring blade 5) is rotationally driven by a drive motor 3 provided in the processing machine 2. The drive motor 3 is a hydraulic motor that is operated by electric power generated by the generator 14a.

  The winch 10 includes a drum 10a that winds the suspension wire 10c, and a boom 10b that adjusts the overhang position (front-rear direction position) of the suspension wire 10c. In this embodiment, the processing machine 2 is suspended by a large number of parallel hanging wires 10c. The boom 10b is rotated around the lower end by a hydraulic cylinder or the like, and the position of the tip of the boom 10b is changed to adjust the protruding position of the suspension wire 10c. Since the present invention enables construction even at a site where the height is severely limited, the length of the boom 10b is about 10 m at the maximum, and more preferably about 5 m. That is, the height of the winch 10 is about 10 m at the maximum and is preferably 5 m or less.

  The winch 10 is operated by electric power generated by another generator 14b. On the work boat 13, a generator 14c for supplying power to other devices is also installed.

  One end of the supply line 8 is connected to the supply source of the ground improvement chemical S. The supply line 8 extends along the stirring blade 5 so as to penetrate the inside of the processing machine 2 up and down.

  Discharge ports 9 are provided at the positions of the respective stirring blades 5. Specifically, as illustrated in FIG. 6, the discharge port 9 is provided at a position midway in the blade length direction of the stirring blade 5. The discharge port 9 can also be provided at the position of the blade tip of the stirring blade 5. Preferably, as illustrated in FIG. 6, the horizontal distances from the rotation shaft 4 of the discharge ports 9 are made different. That is, it is preferable that the discharge ports 9 provided at the positions of the respective stirring blades 5 have the discharge ports 9 having different horizontal distances from the rotating shaft 4.

  In this embodiment, the supply pipe 8 a extends in the length direction from the rotating shaft 4 along the stirring blade 5, and the tip of the extended supply pipe 8 a is the discharge port 9. It is also possible to make the inside of the stirring blade 5 hollow and extend the supply line 8 in the longitudinal direction of the stirring blade 5 so that the discharge port 9 is opened in the stirring blade 5.

  The supply line 8 is, for example, a system extending to the upper stirring blade 5 and a system extending to the lower stirring blade 5. The supply management of the ground improvement chemical S and water W to the discharge port 9 at the position of the upper stirring blade 5 and the discharge port 9 at the position of the lower stirring blade 5 is performed on the work ship 13, for example.

  An on-off valve that opens and closes each discharge port 9 can also be installed. When this on-off valve is installed, for example, the upper and lower agitating blades 5 and 5 are controlled so as to switch the opening and closing of the discharge port 9 by controlling the on-off valve. For example, a cement-based slurry is used as the ground improvement chemical solution S.

  The stabilizer 6 is attached to the side surface of the processing machine 2 and has a structure that opens and closes by a cylinder or the like. 3 to 5 show a state in which the stabilizer 6 is closed, and FIGS. 7 and 8 show a state in which the stabilizer 6 is opened (projected).

  The processing machine 2 is provided with a sensor that detects acceleration in three axis directions (X, Y, and Z axis directions), and data detected by the sensor is input to the control device 11. The opening and closing of each stabilizer 6 is independently and independently controlled by the control device 11. Based on the input detection data, the control device 11 controls the opening / closing state of each stabilizer 6 so that the processing device 2 can move in a preset direction, and controls the processing device 2 to an appropriate posture. To do.

  In this embodiment, four stabilizers 6 are attached at equal intervals in the circumferential direction of the processor 2, but the number is not limited to four and may be three or more. The stabilizers 6 are preferably arranged at equal intervals in the circumferential direction of the processor 2.

  The processor 2 is further provided with an upper rotary blade 7 at the upper end. It is optional to provide the upper rotor blade 7. By rotating the upper rotor blade 7, the earth pressure acting on the processor 2 in the ground B is reduced. Specifically, the earth and sand existing above the processing machine 2 is scraped by the rotary blades 7 and the earth and sand are moved downward through the gaps on the side of the processing machine 2 to thereby reduce the earth pressure acting on the processing machine 2. Reduce. The upper rotary blade 7 and the stirring blade 5 are driven to rotate independently of each other.

  A rod-shaped sub-leader 12 is detachably attached to both side surfaces of the processing machine 2 of this embodiment. The processor 2 is configured to be movable up and down along the sub-leader 12. The sub reader 12 is used to accurately install the processor 2 at a predetermined position measured by GPS. The sub-leader 12 is erected at an appropriate position on the ground B so that the processor 2 that moves downward is accurately placed at a predetermined position on the ground B. As described above, it is sufficient for the sub-leader 12 functioning as the positioning means of the processing machine 2 to have a length of about the water depth.

  Next, a method for improving the ground B using the ground improvement device 1 will be described.

  First, as illustrated in FIG. 9, the suspension wire 10 c is fed out from the drum 10 a of the winch 10, and the processing machine 2 suspended from the work ship 13 is guided by the sub-leader 12 erected vertically to move downward in the water. Move. And the front-end | tip of the rotating shaft 4 is made to land on the predetermined position of the ground B to be improved, and the processing machine 2 is set on the ground B. By using the sub reader 12, the processor 2 is accurately set at a predetermined position on the ground B.

  In addition, the code | symbol B2 of FIGS. 9-15 shows the upper end position of the ground improvement object range, and code | symbol B3 has shown the upper end position of the lower end part area | region of the ground improvement object range. Therefore, the range (B3 to B1 region) from the upper end position B3 of the lower end region to the support ground B1 is the lower end region of the ground improvement target range. The depth (length in the vertical direction) of the lower end region is appropriately determined by design and is, for example, about 2 m to 3 m.

  Next, as illustrated in FIG. 10, the rotating shaft 4 is driven to rotate, and the stirring blade 5 extending in the horizontal direction from the rotating shaft 4 is driven to rotate while the processing machine 2 (the lower end of the rotating shaft 4) is in the ground improvement target range. Is lowered to a position approximately 0.5 m above the upper end position B3 of the lower end region. When the processor 2 is lowered, the suspension wire 10c is fed out from the drum 10a. During the descent, the water W supplied through the supply line 8 is discharged from the discharge port 9 arranged at the position of the lower stirring blade 5. Note that the water W may not be discharged depending on the construction conditions.

  Subsequently, as illustrated in FIG. 11, the ground improvement chemical S supplied through the supply line 8 is disposed at the position of the lower stirring blade 5 while the processing device 2 is lowered while the stirring blade 5 is driven to rotate forward. It discharges from the discharge port 9 made. That is, in this downward movement process of the processor 2, the ground improvement chemical S and the soil of the ground B are agitated and mixed.

  Since the processor 2 is suspended via the suspension wire 10c, the posture is likely to be unstable. Therefore, in the present invention, when the processor 2 is moving downward in the ground B, the stabilizer 6 is opened and closed to control the processor 2 to an appropriate posture.

  After excavating the ground B and the stirring blade 5 (the lower end of the rotating shaft 4) reaches the support ground B1, the winch 10 is operated and suspended while the stirring blade 5 is driven in reverse rotation as illustrated in FIG. The wire 10c is wound around the drum 10a and the processor 2 is moved upward. During this upward movement, the ground improvement chemical S is not discharged from the discharge port 9. That is, in this upward movement process of the processing machine 2, the ground improvement chemical solution S and the soil of the ground B are simply stirred and mixed without newly adding the ground improvement chemical solution S.

  Even when moving upward in the ground B, the processor 2 tends to be unstable in posture. Therefore, in the present invention, even when the processing machine 2 is moving upward in the ground B, the respective stabilizers 6 are opened and closed as necessary to control the processing machine 2 to an appropriate posture.

  After the processor 2 is moved upward until the lower stirring blade 5 is close to the upper end position B3 of the lower end region of the ground improvement target range, the stirring blade 5 is driven to rotate forward as illustrated in FIG. Then, the processor 2 is lowered. During this lowering, the ground improvement chemical S is not discharged from the discharge port 9. That is, in this downward movement process of the processor 2, the ground improvement chemical solution S and the soil of the ground B are merely stirred and mixed without newly adding the ground improvement chemical solution S.

  After the agitating blade 5 (lower end of the rotating shaft 4) reaches the support ground B1, as shown in FIG. 14, the winch 10 is operated while the agitating blade 5 is driven to rotate reversely, and the suspension wire 10c is moved to the drum 10a. The processor 2 is wound up and moved upward. During the upward movement, the ground improvement chemical solution S is discharged from the discharge port 9 disposed at the position of the upper stirring blade 5. That is, in this upward movement process of the processor 2, the ground improvement chemical S and the soil of the ground B are agitated and mixed while newly adding the ground improvement chemical S.

  After the upper stirring blade 5 reaches the vicinity of the upper end position B2 of the ground improvement target range, the discharge of the ground improvement chemical S from the discharge port 9 is stopped, and as shown in FIG. Lift wing 5) onto ground B. The construction is completed by performing the same process at another position in the construction range. The ground B to be constructed is firmly improved by the ground improvement chemical S through this series of processes.

  12 and 13, the stirring blade 5 reciprocates up and down twice in the lower end region (B3 to B1 region) of the ground improvement target range. The number of reciprocations of the stirring blade 5 can be appropriately changed depending on the properties of the ground B. Moreover, the method of rotation of the stirring blade 5 and the discharge of the ground improvement chemical | medical solution S in the process illustrated in FIGS. 10-15 can be performed by arranging suitably. For example, the ground improvement chemical S can be discharged when the processor 2 is lowered to a position about 0.5 m above the upper end position B3.

  As described above, in the present invention, it is not necessary to attach the stirring blade 5 to a long rod as in the prior art, and accordingly, no soot is required. Therefore, it is possible to perform construction even at a site where height restrictions are severe.

  Moreover, since the stabilizer 6 is attached to the processing machine 2, the processing machine 2 that moves up and down in the ground B can be brought into an appropriate posture by the stabilizer 6 without attaching the stirring blade 5 to the long rod as in the prior art. Can be controlled. Thereby, the processing machine 2 can be moved up and down stably in the ground B. Therefore, the ground can be improved with high accuracy as designed.

  In this embodiment, when the processing machine 2 is moved upward in the ground B, the processing machine 2 can be pushed upward by rotationally driving the upper rotary blade 7. Thereby, the processor 2 can be moved upward more smoothly.

  As in this embodiment, in the construction where the winch 10 is installed on the work boat 13 and the processing machine 2 moves up and down in the ground B at the bottom of the water, even if the work boat 13 is shaken by the wave, the peristalsis of the suspension wire 10c Is transmitted to the processor 2 via In the case where the stirring blade 5 is attached to a long rod as in the prior art, the peristalsis of the work boat 13 is directly transmitted to the processing machine 2 through the rod, which is disadvantageous in preventing the processing machine 2 from shaking. However, in the present invention, the peristalsis of the work boat 13 is difficult to be transmitted to the processing machine 2, which is advantageous for accurate and safe construction. In addition, this invention is applicable not only when improving a water bottom ground, but also when improving a land ground.

  As illustrated in FIG. 6, if the discharge ports 9 having different horizontal distances from the rotation shaft 4 are present (mixed), the ground improvement chemical S can be easily mixed into the ground B evenly.

DESCRIPTION OF SYMBOLS 1 Ground improvement apparatus 2 Processing machine 3 Drive motor 4 Rotating shaft 5 Stirring blade 6 Stabilizer 7 Upper rotary blade 8 Supply line 8a Supply pipe 9 Discharge port 10 Winch 10a Drum 10b Boom 10c Suspension wire 11 Control device 12 Subleader 13 Work ship 14a, 14b, 14c Generator B Ground B1 Support ground S Ground improvement chemical

Claims (8)

  In a ground improvement device comprising a processing machine having a stirring blade that moves up and down in the ground and a supply line that supplies a ground improvement chemical solution into the ground, the rotating shaft to which the stirring blade is attached and rotationally driven is the processing machine. A ground improvement device comprising: a winch that protrudes downward from above and moves the processing machine up and down via a hanging wire; and a stabilizer that is attached to the processing machine and controls the attitude of the processing machine.   The ground improvement apparatus of Claim 1 with which the said processing machine is provided with the rotary blade which reduces the earth pressure which acts on a processing machine in the ground.   The ground improvement device according to claim 1 or 2, wherein the winch is installed in a ship, and the processing machine moves up and down in the water bottom ground.   A plurality of the stirring blades are extended in the horizontal direction from different positions in the circumferential direction of the rotating shaft, the ground improvement chemical solution discharge port is provided at each stirring blade position, and the horizontal distance from the rotating shaft is The ground improvement apparatus in any one of Claims 1-3 in which a different discharge outlet exists. The ground is excavated to a predetermined depth by rotating the stirring blade in the ground while rotating, and after the excavation or after the excavation, the ground improvement chemical solution is supplied into the ground, and the stirring blade is rotated and moved upward. In the ground improvement method of performing ground improvement by stirring and mixing the ground improvement chemical in the ground,
A processing machine is provided with a rotating shaft protruding downward and attached to the stirring blade. The processing machine is connected to a suspension wire wound around a winch, and is rotated downward while rotating the stirring blade in the ground. When excavating the ground to a predetermined depth by moving it, the winch is actuated to feed out the suspension wire, and the processing machine is moved downward by controlling the attitude of the processing machine with a stabilizer attached to the processing machine. When the ground improvement chemical solution is stirred and mixed in the ground by rotating the stirring blade, the winch is operated to wind the suspension wire, and the stabilizer is used to wind the suspension wire. A ground improvement method characterized by controlling a posture and moving a processor upward.   The ground improvement method according to claim 5, wherein when the processing machine is provided with a rotary blade and the processing machine is moved upward in the ground, the earth pressure acting on the processing machine is reduced by rotating the rotary blade.   The ground improvement method according to claim 5 or 6, wherein the winch is installed in a ship and the processing machine is moved up and down in the bottom ground to improve the ground of the bottom bottom.   A plurality of the stirring blades are extended in the horizontal direction from different positions in the circumferential direction of the rotating shaft, and the ground improvement chemical solution is introduced into the ground from a plurality of positions having different horizontal distances from the rotating shaft of the plurality of stirring blades. The ground improvement apparatus in any one of Claims 5-7 to discharge.

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