JP2011231467A - Soil improvement construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soil improvement construction machine that dose not wastefully consume a hardening material injected into a drilling hole and is suitable for a high pressure injection stirring construction method.SOLUTION: A soil improvement construction machine that pulls up a rod from a drilling hole formed in the ground while rotating the rod and performs soil improvement by injecting a hardening material from a nozzle at the tip of the rod at a high pressure comprises: a first chuck that is mounted in a vertically movable manner to a rod rotated by a motor for driving the chuck and rotatably holds the rod; a second chuck that is mounted in a vertically movable manner to the rod for driving the chuck and rotatably holds the rod while the first chuck rotatably holds it alternatively; a first hydraulic cylinder whose piston moves the first chuck vertically; and a second hydraulic cylinder whose piston moves the second chuck vertically in the opposite direction of the movement of the piston of the first hydraulic cylinder.

Description

  The present invention relates to a ground improvement construction machine using a high-pressure jet agitation method, and more particularly, to a ground improvement construction machine having a short construction time and no consumption loss in a hardened material injected into a drilling hole.

  Patent Document 1 discloses a rotary drive unit, a rotary table, a chuck drive rod (Kelly rod) connected to a transmission system in the rotary table, and a chuck drive rod that is slidable in the vertical direction. 1 chuck and a second chuck fixed to the rotary table, step by step while rotating the chemical injection / excavation rod while sandwiching the chemical injection / excavation rod between the first chuck and the second chuck. There is shown a chemical injection / excavator that raises a chemical injection / excavation rod one stroke at a time and injects a chemical for improving the ground.

  In the chemical injection method disclosed in Patent Document 1, the chemical injection / excavation rod is pulled up in a stepwise manner and injected into the excavation hole from the nozzle at the tip of the chemical injection / excavation rod. The chemical solution injection / drilling rod is pulled up by the first chuck and the second chuck. First, the first chuck moves upward by one stroke while grasping the chemical injection / excavation rod. Next, the first chuck is lowered by one stroke without grasping the chemical injection / excavation rod for re-holding. During this time, the second chuck holds the chemical solution injection / excavation rod so as not to fall. Again, the first chuck moves up one stroke by grasping the chemical injection / excavation rod. This is repeated, and the chemical injection / excavation rod is pulled up.

  In the chemical solution injection method, if the time required for the chemical solution injection / excavation rod to move up by one stroke and the time required for the first chuck to be replaced are set as one step time, the required chemical solution is injected within this one step time. Therefore, even if the chemical solution injection / excavation rod is stopped at the time of gripping, no loss occurs in the chemical solution injection. In such a chemical solution injection method, for example, the pressure of the chemical solution at the nozzle tip is 0.2 to 0.5 MPa, the stroke is 25 to 50 cm, the injection speed is 16 liters / minute, and the time per step is several minutes to Tens of minutes.

  The high-pressure jet agitation method is a method in which a slurry-like hardener is jetted at a high pressure, the periphery of the excavation hole is agitated with a jet, and solidified in a short time. When a curing material is used in place of a chemical solution in a chemical injection / excavator as shown in Patent Document 1 and this is applied to a high-pressure jet agitation method, there are the following problems. In other words, the high-pressure jet agitation method is a method in which one step is raised from 2.5 cm to 20 cm in a short time of several seconds to several tens of seconds, and is changed every 50 cm for a small construction machine with a short stroke of 50 cm. As a result, a stop time of several tens of seconds occurs, resulting in a consumption loss. In order to avoid this, there is a method in which the length of one stroke is 3 m to 5 m, but the construction machine is enlarged and cannot be used in a narrow place.

JP-A-7-324326

  An object of the present invention is to provide a ground improvement construction machine suitable for the high-pressure jet agitation method without any loss of consumption of the hardener in the step of spraying into a borehole.

In the ground improvement construction machine according to claim 1 according to the present invention, the rod is lifted from the excavation hole formed in the ground while rotating, and the hardened material is injected from the nozzle at the tip of the rod at a high pressure to improve the ground. In the ground improvement construction machine to be performed, it is attached to a chuck driving rod rotated by a motor so as to be movable up and down, and is attached to the chuck driving rod so as to be movable up and down, and a first chuck that grips and rotates the rod A second chuck for rotating the rod by gripping the rod alternately with the first chuck, a first hydraulic cylinder for moving the first chuck up and down by a piston, and a piston for the first hydraulic cylinder by using the second chuck by a piston And a second hydraulic cylinder that moves up and down in directions opposite to each other.
Furthermore, the ground improvement construction machine according to claim 2 according to the present invention includes the first chuck, the second chuck, the first hydraulic cylinder, and the second hydraulic cylinder, and the rod is lifted when the rod is pulled up. The first chuck and the second chuck are alternately gripped and released, and the rod is continuously pulled up without generating time for gripping with the chuck every stroke. Features.

  The first chuck and the second chuck are controlled such that the vertical movement speed when the rod is not gripped is faster than the speed when the rod is gripped.

  When the first chuck or the second chuck approaches the position at which one of the first chuck or the second chuck holding the rod finishes the vertical movement, the other of the other chucks not holding the rod The first chuck or the second chuck grips the rod and starts to move up and down.

  According to the ground improvement construction machine according to the first and second aspects of the present invention, the first hydraulic cylinder and the second hydraulic cylinder are provided with the first and second chucks respectively moving up and down by the first and second hydraulic cylinders. The pistons are moved up and down in opposite directions, and the vertical movement of the rod is alternately performed by the first chuck and the second chuck, so that there is no stop of the vertical movement of the rod caused by the lowering of the cylinder every time it is held. . The rotation of the rod is continued and the pulling operation is continued, so that the curing material is not injected unnecessarily at one place, and the consumption loss of the curing material can be prevented. In addition, the construction time can be shortened because the lifting of the rod is not stopped every time the grip is changed.

  Since the first chuck and the second chuck are controlled so that the speed when the rod is not gripped is higher than the speed when the rod is gripped, the first chuck or the second chuck gripping the rod When the chuck finishes the vertical movement of one stroke, the first chuck or the second chuck not holding the rod can be reliably returned to the start position of the vertical movement. That is, the next vertical movement of the rod can be continued without stopping.

  When the first chuck or the second chuck approaches the position where one of the first chuck or the second chuck holding the rod finishes the vertical movement, the other first chuck or the second chuck not holding the rod Since the rod grips the rod and starts to move up and down, the rod is simultaneously driven by the first chuck and the second chuck, so that an instantaneous stop at the time of gripping can be prevented. The rod lifting or pushing operation can be further continued.

It is a principal part block diagram of the ground improvement construction machine by this invention. It is a top view of FIG. It is operation | movement explanatory drawing of a 1st hydraulic cylinder and a 1st chuck | zipper. It is operation | movement explanatory drawing of a 2nd hydraulic cylinder and a 2nd chuck | zipper. It is operation | movement explanatory drawing of the 1st chuck | zipper and the 2nd chuck | zipper at the time of hardening material injection. It is operation | movement explanatory drawing of the 1st chuck | zipper and the 2nd chuck | zipper at the time of drilling. It is explanatory drawing of the high pressure injection stirring construction method using the ground improvement construction machine of FIG.

  Hereinafter, the ground improvement construction machine according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram of a main part of a ground improvement construction machine 100 according to the present invention. The ground improvement construction machine 100 includes a chuck driving rod 4 driven by a motor 7, a first chuck 1 that is attached to the chuck driving rod 4 so as to be movable up and down, and that grips and rotates the rod 3, and for chuck driving. A first chuck that is attached to the rod 4 so as to be movable up and down, grips and rotates the rod 3, and moves up and down alternately with the first chuck 1, and moves the first chuck 1 up and down with a piston 5a. The hydraulic cylinder is composed of a hydraulic cylinder and a second hydraulic cylinder 6 that moves the second chuck 2 up and down in a direction opposite to the piston 5a of the first hydraulic cylinder 5 by a piston 6a. The curing material 10 is supplied to the rod 3 at a high pressure and sprayed from the nozzle 8. The injected hardener is agitated with surrounding soil particles. The rod 3 rotates when held by the first chuck 1 or the second chuck 2.

  FIG. 2 is a plan view of FIG. The rotation direction of the chuck driving rod 4 and the rotation direction of the first chuck 1 and the second chuck 2 are the same. When the first chuck 1 or the second chuck 2 grips the rod 3, the rod 3 also rotates in the same direction as the first chuck 1 or the second chuck 2.

  FIG. 3 is an explanatory view of the operation of the first hydraulic cylinder 5 and the first chuck 1. (A) is the state which the piston 5a of the 1st hydraulic cylinder 5 protruded, and the 1st chuck | zipper 1 is pulled up upwards. (B) is a state in which the piston 5a of the first hydraulic cylinder 5 is retracted, and the first chuck 1 is pushed downward. Thus, the vertical movement of the first chuck 1 is performed by the piston 5 a of the first hydraulic cylinder 5. The vertical movement is a vertical movement of the length of one stroke of the piston 5a. This is repeated, and the rod 3 can be lifted or pushed down. In this embodiment, the piston 5a of the first hydraulic cylinder 5 is attached so as to face upward.

  FIG. 4 is an explanatory view of the operation of the second hydraulic cylinder 6 and the second chuck 2. (A) is a state in which the piston 6a of the second hydraulic cylinder 6 protrudes, and the second chuck 2 is pushed downward. (B) is a state in which the piston 6a of the second hydraulic cylinder 6 is retracted, and the second chuck 2 is pulled upward. The vertical movement of the second chuck 2 is performed by the piston 6 a of the second hydraulic cylinder 6. In the present embodiment, since the piston 5a of the first hydraulic cylinder 5 faces upward, the piston 6a of the second hydraulic cylinder 6 is attached so as to face downward. For example, the piston 5a of the first hydraulic cylinder 5 and the piston 6a of the second hydraulic cylinder 6 may be attached so as to face upward.

  The first hydraulic cylinder 5 and the second hydraulic cylinder 6 are configured to perform two systems of hydraulic control so that the speed at which the pistons 5a and 6a protrude is different from the speed at which the pistons 5a retract. Further, the first hydraulic cylinder 5 and the second hydraulic cylinder 6 are provided with magnetic sensors (not shown) inside, and the positions of the pistons 5a and 6a can be detected. As a specific example, P1 is a position where the pistons 5a and 6a are retracted, P7 is a protruding position, P2 to P6 are midway positions, and if P1 to P7 are detected, the first chuck 1 or the second chuck 2 is moved up and down. You can know the current position. The position of the first chuck 1 and the second chuck 2 may be directly detected by the position sensor, instead of the magnetic sensor provided inside the first hydraulic cylinder 5 and the second hydraulic cylinder 6.

  As shown in FIGS. 3 and 4, the piston 5a of the first hydraulic cylinder 5 and the piston 6a of the second hydraulic cylinder 6 are moved up and down in opposite directions. When the piston 5a is protruded upward as shown in FIG. 3A, the piston 6a is protruded downward as shown in FIG. 4A. During this time, the first chuck 1 in FIG. 3 (A) holds the rod 3 for lifting, and the second chuck 2 in FIG. 4 (A) does not hold the rod 3 for preparation for the next lifting. Conversely, when the piston 5a is retracted downward as shown in FIG. 3B, the piston 6a is retracted upward as shown in FIG. 4B. During this time, the first chuck 1 in FIG. 3B does not grip the rod 3 in preparation for the next lifting, and the second chuck 2 in FIG. 4B grips the rod 3.

  FIG. 5 is an operation explanatory view of the first chuck and the second chuck when the hardened material is injected into the excavation hole. It is assumed that the drilling holes have been drilled in advance. Further, the curing material 10 is jetted at a high pressure from the nozzle 8 at the tip of the rotating rod 3. 5A to 5J show the positions of the first chuck 1 and the second chuck 2. FIG. When the content below the arrow Ya is operated, the state on the left side of the arrow Ya is changed to the state on the right side of the arrow Ya. Ya indicates opening / closing of the first chuck 1 or the second chuck 2 as (open) and (closed). (Open) indicates that the chuck is opened and the rod 3 is not gripped. (Closed) indicates that the chuck is closed and the rod 3 is gripped. If the chuck is closed, the chuck is rotated by the chuck driving rod 4, so that the rod 3 is also rotated. An arrow Yb indicates the traveling direction of the first chuck 1 or the second chuck 2. This corresponds to whether the pistons 5a and 6a of the first hydraulic cylinder 5 or the second hydraulic cylinder 6 are projected or retracted.

  As shown in FIG. 5, the first chuck 1 and the second chuck 2 move toward and away from each other. The second chuck 2 is closed, for example, between (b) and (g), and grips the rod 3 and pulls it up by one stroke. The first chuck 1 is closed between, for example, (g), (h), (i), (j), (a), and (b), and is lifted by one stroke while gripping and rotating the rod 3. In this way, the rod 3 is pulled up alternately by the first chuck 1 and the second chuck 2.

  As shown in FIG. 5, the first chuck 1 is quickly returned while the second chuck 2 pulls up the rod 3 between (b) and (g). This can be realized by speeding up the retraction of the piston 5a of the first hydraulic cylinder 5. The second chuck 2 is quickly returned while the first chuck 1 pulls up the rod 3 between (g), (h), (i), (j), (a), and (b). This can be realized by increasing the protruding speed of the piston 6a of the second hydraulic cylinder 6. As a result, the other chuck that performs the next lifting operation can be reliably returned to the starting position until the one-stroke lifting operation is completed by one chuck.

  As shown in FIG. 5, “simultaneous lifting” of the rod 3 by the first chuck 1 and the second chuck 2 is performed. In (b), the first chuck 1 pulls up the rod 3, and at the same time, the rod 3 is gripped by the second chuck 2 quickly returned to start the pulling up. This is because the sensor detects that the piston 5a of the first hydraulic cylinder 5 has protruded to reach the position P6 (position where the end of the one-stroke pull-up operation is near), and the second chuck 2 starts to be lifted. In (g), the second chuck 2 pulls up the rod 3, and at the same time, the rod 3 is gripped by the first chuck 1 quickly returned to start the pulling up. This is because the sensor detects that the piston 6a of the second hydraulic cylinder 6 has retracted and has reached the position P2 (the position where the end of the one-stroke pull-up operation is near), and starts to pull up the first chuck 1. . Simultaneous pulling raises the rod 3 by both the first chuck 1 and the second chuck 2. According to this, before the first chuck 1 or the second chuck 2 stops at the top dead center, the pulling by the second chuck 2 or the first chuck 1 can be started.

  In the present embodiment, the rod 3 is rotated at a variable speed at a rotational speed of 15 to 40 rpm. At the time of injection of the hardened material 10, the first hydraulic cylinder 5 and the second hydraulic cylinder 6 are operated, and the rod 3 is pulled up about 2 to 20 cm every about 3 to 20 seconds. For example, the rod 3 is rotated about 3 times by raising a stroke of 5 cm. The pressure of the curing material 10 is 20 to 60 MPa.

  FIG. 6 is an operation explanatory view of the first chuck and the second chuck during drilling in the ground improvement. By operating the first chuck 1 and the second chuck 2 as shown in FIG. 6, the efficiency of drilling can be increased. 6A to 6J show the positions of the first chuck 1 and the second chuck 2. FIG. (Open) indicates that the chuck is opened and the rod 3 is not gripped. (Closed) indicates that the chuck is closed and the rod 3 is gripped. If the chuck is closed, since the chuck is rotated by the chuck driving rod 4, the rod 3 also rotates. When the content shown below the arrow Ya is operated, the state on the left side of the arrow Ya is changed to the state on the right side. An arrow Yb indicates the traveling direction of the first chuck 1 or the second chuck 2.

  As shown in FIG. 6, the first chuck 1 and the second chuck 2 move toward and away from each other. The second chuck 2 is closed between, for example, (b) to (g), and holds the rod 3 and pushes it down by one stroke. The first chuck 1 is closed, for example, between (g), (h), (i), (j), (a), and (b), and holds the rod 3 and pushes it down by one stroke. Thus, the rod 3 is pushed down alternately by the first chuck 1 and the second chuck 2. If the rod 3 is gripped by the first chuck 1 or the second chuck 2, the rod 3 is simultaneously rotated.

  As shown in FIG. 6, the 1st chuck | zipper 1 is made to return quickly, for example between (b)-(g). This can be realized by speeding up the protrusion of the piston 5a of the first hydraulic cylinder 5 contrary to the time of pulling up. For example, the second chuck 2 is rapidly returned between (g), (h), (i), (j), (a), and (b). This can be realized by speeding up the retraction of the piston 6a of the second hydraulic cylinder 6.

  As shown in FIG. 6, simultaneous drilling by both the first chuck 1 and the second chuck 2 is performed by simultaneously depressing the rod 3 by the first chuck 1 and the second chuck 2. In (b), the first chuck 1 pushes down the rod 3, and at the same time, the rod 3 is gripped by the second chuck 2 quickly returned to start pushing down. This is because the sensor detects that the piston 5a of the first hydraulic cylinder 5 has retracted and has reached the position P2 (the position where the end of the one-stroke push-down operation is almost finished) and starts to push the second chuck 2 down. is there. In (g), the second chuck 2 pushes down the rod 3, and at the same time, the rod 3 is gripped by the first chuck 1 quickly returned to start pushing down. This is because the sensor detects that the piston 6a of the second hydraulic cylinder 6 has retracted and has reached the position P6 (the position where the end of the one-stroke pressing operation is almost finished) and starts to press the first chuck 1 down. is there. Simultaneous push-down pushes down the rod 3 by both the first chuck 1 and the second chuck 2. According to this, before the 1st chuck | zipper 1 or the 2nd chuck | zipper 2 stops at a bottom dead center, pushing down by the 2nd chuck | zipper 2 or the 1st chuck | zipper 1 can be started.

  FIG. 7 is an explanatory diagram of a high-pressure jet stirring method using the ground improvement construction machine 100. As shown in FIG. 7, the construction procedure of the high-pressure jet stirring method is as follows: (1) First, the ground improvement construction machine 100 is moved to center the ground 20. (2) Next, the excavation hole 11 is drilled in the ground with the drill bit 9 at the tip of the rod 3. (3) After the excavation hole 11 is formed, the hardened material 10 is jetted and stirred from the nozzle 8 at the tip of the rod 3 at a high pressure. The curing material 10 is fed through the curing material pumping hose 12 and the rod 3. In the example of FIG. 7, the nozzle 8 is a two-way injection nozzle. (4) Continue to inject the curing material 10 while rotating and pulling up the rod 3, and (5) Finally, the nozzle 8 is pulled up until it is positioned at the upper end of the design improvement length, stopping the injection and pulling out the blanking portion. Creation is complete. In this way, when the ground is improved, the rod 3 is always rotated and pulled up, so there is no loss in chuck holding time and consumption of the hardener. Further, when drilling, the rod 3 can always be rotated for drilling, so that there is no time loss for gripping.

  The hardening material 10 is a slurry-like material containing a cement-based solidifying material, and is sprayed from the nozzle 8 around the excavation hole 11. Since the nozzle 8 is rotated by the rotation of the rod 3, the jet entrains the soil particles around the excavation hole 11, and mixing and stirring with the hardening material 10 are performed. For this reason, the formed cylindrical improvement body can be made firm.

  According to this invention, it is suitable as a ground improvement construction machine with no wasteful consumption loss of the hardened material.

DESCRIPTION OF SYMBOLS 1 1st chuck 2 2nd chuck 3 Rod 4 Chuck drive rod 5 1st hydraulic cylinder 5a 1st piston 6 2nd hydraulic cylinder 6a 2nd piston 7 Motor 8 Nozzle 9 Drill bit 10 Hardening material 11 Drilling hole 12 Hardening material pressure feed Hose 20 Ground 100 Ground improvement construction machine

Claims (4)

In the ground improvement construction machine that pulls up the rod while rotating it from the excavation hole formed in the ground, and improves the ground by injecting the hardened material at a high pressure from the nozzle at the tip of the rod,
A first chuck that is attached to a chuck driving rod that is rotated by a motor so as to be movable up and down, and that grips and rotates the rod;
A second chuck which is attached to the chuck driving rod so as to be vertically movable, and which grips and rotates the rod alternately with the first chuck;
A first hydraulic cylinder that moves the first chuck up and down by a piston;
A ground improvement construction machine, comprising: a second hydraulic cylinder that moves the second chuck up and down in a direction opposite to the piston of the first hydraulic cylinder by a piston.
In the ground improvement construction machine that pulls up the rod while rotating it from the excavation hole formed in the ground, and improves the ground by injecting the hardened material at a high pressure from the nozzle at the tip of the rod,
A first chuck that is attached to a chuck driving rod that is rotated by a motor so as to be movable up and down, and that grips and rotates the rod;
A second chuck which is attached to the chuck driving rod so as to be vertically movable, and which grips and rotates the rod alternately with the first chuck;
A first hydraulic cylinder that moves the first chuck up and down by a piston;
A second hydraulic cylinder that moves the second chuck up and down in a direction opposite to the piston of the first hydraulic cylinder by a piston;
When the rod is lifted, the rod is alternately gripped and released alternately by the first chuck and the second chuck, and continuously without the time for gripping by the chuck every stroke. A ground improvement construction machine characterized by pulling up.
The first chuck and the second chuck are controlled so that a vertical movement speed when the rod is not gripped is higher than a speed when the rod is gripped. Item 3. The ground improvement construction machine according to item 1 or 2.
  When the first chuck or the second chuck approaches the position at which one of the first chuck or the second chuck holding the rod finishes the vertical movement, the other of the other chucks not holding the rod The ground improvement construction machine according to claim 3, wherein the first chuck or the second chuck grips the rod and starts to move up and down.

Images