JP5212258B2 - Ground improvement method and ground improvement device - Google Patents

Description

  The present invention relates to a ground improvement method and a ground improvement device for improving a ground by injecting a chemical material into the ground.

Conventionally, a rod is inserted into an excavated hole, and a stirring blade provided on the side surface of the rod is rotated while a chemical for improving the ground is injected from an injection port provided on the rod, thereby forming a cylindrical shape. The ground was improved by forming a ground improvement body.
For example, Patent Document 1 discloses a ground improvement method that uses a ground improvement device provided with a stirring blade and injects a chemical from the tip of the stirring blade to improve the ground. In this construction method, first, the water is ejected from the tip of the stirring blade in a state where the stirring blade is substantially horizontal, the rod is lifted by a predetermined distance, and the ground is excavated and stirred. After lowering the rod only, the material is sprayed from the tip of the stirring blade, and the rod is pulled up again by a predetermined distance to reduce the amount of mud and form a large-diameter ground improvement body. It is.

JP-A-5-33334

  However, in the ground improvement method described in Patent Document 1, a large-diameter ground improvement body can be formed by injecting a chemical material from the tip of the stirring blade. While a uniform improved body is created by stirring, the outer part of the stirring blade is not forcedly stirred by the stirring blade, so a ground improvement body with non-uniform distribution of chemicals is formed. There is a possibility that.

  Therefore, the present invention has been made in view of the above-described problems, and it is possible to improve a large diameter with a small machine, and to form a ground improvement body with a uniform distribution of chemicals. An object of the present invention is to provide a ground improvement method and a ground improvement device.

The ground improvement method of the present invention includes a rod having a first injection port on the outer periphery for injecting a chemical for improving the ground, and the rod at a position closer to the tip than the first injection port of the rod. An injection device that protrudes by a predetermined length in the radial direction and has a second injection port for injecting the medicinal material at the protruding end, and the injection device at a position closer to the tip than the injection device of the rod And a stirring device that protrudes in the radial direction of the rod for a longer period of time, the spray device of the ground improvement device and the stirring device that are in a state along the longitudinal direction of the rod, and the rod from the ground into the ground Inserting to a predetermined depth of,
A step of pulling up the rod to a first predetermined distance while injecting a chemical from the first injection port;
A step of causing the injection device to protrude in a radial direction of the rod while injecting a chemical from the first injection port;
Raising the rod to a second predetermined distance while stirring the ground by the spray device;
A step of projecting the stirring device in a radial direction of the rod while injecting a chemical from the first injection port and the second injection port;
And a step of pulling up the rod by a predetermined distance while stirring the ground with the jetting device and the stirring device.

  According to the ground improvement method of the present invention, when inserting the ground improvement device into the ground, by bringing the injection device and the stirring device close to each other along the outer peripheral surface of the rod, the injection device from the outer peripheral surface of the rod and The amount of protrusion of the stirring device can be negligible. Therefore, when inserting a rod into the hole drilled from the ground surface to the ground, the injection device and the stirring device do not hinder.

  Further, by injecting the chemical material from the second injection port of the injection device, it is possible to perform injection mixing farther than the injection from the first injection port. Furthermore, in addition to the ground mixed by injection from the first injection port, the ground mixed by injection from the second injection port can be stirred by the stirring device. Therefore, since the uniform mixture of a chemical | medical material and soil can be created in a large diameter in the ground, a highly reliable ground improvement body can be formed in a wide range.

  Further, the inside of the ground mixed by injection from the first injection port is stirred by the injection device, and the inside of the ground mixed by injection from the second injection port is stirred by the stirring device, whereby the injection device And since the rotational resistance at the time of rotation of a stirring apparatus is reduced, the rotational torque required in order to rotate an injection apparatus and a stirring apparatus may be small. Thereby, a ground improvement apparatus main body can be reduced in size.

  In addition, since the first injection port and the second injection port having different positions in the rod diameter direction are provided, the diameter of cutting the ground by the injection of the chemical material from one injection port may be small. The amount of chemicals injected into the ground can be reduced. Thereby, the amount of mud is also reduced, and the cost required for the mud treatment can be reduced.

The ground improvement device of the present invention is a ground improvement device that improves the ground by jetting and stirring a chemical material on the ground,
A rod having a first injection port on the outer periphery for injecting the chemical material;
A second injection port for injecting the medicinal material is provided at the tip end side of the first injection port of the rod so as to protrude by a predetermined length in the radial direction of the rod. An injection device in the part;
A stirrer for agitating the ground, provided at a position on the tip side of the ejector of the rod so as to protrude in the radial direction of the rod longer than the ejector. To do.

  According to the present invention, since the injection device that protrudes in the radial direction of the rod and has the second injection port is provided, the injection mixing with the chemical material is performed farther than the injection from the first injection port. Can do. Further, the ground mixed by injection from the second injection port in addition to the ground mixed by injection from the first injection port by the stirring device protruding longer in the radial direction of the rod than the injection device Can also be stirred. Therefore, since the uniform mixture of a chemical | medical material and soil can be created in a large diameter in the ground, a highly reliable ground improvement body can be formed in a wide range.

  Furthermore, the inside of the ground mixed by injection from the first injection port is agitated by the injection device, and the inside of the ground mixed by injection from the second injection port is stirred by the agitation device, whereby the injection device And since the rotational resistance at the time of rotation of a stirring apparatus is reduced, the rotational torque required in order to rotate an injection apparatus and a stirring apparatus may be small. Thereby, a ground improvement apparatus main body can be reduced in size.

  In addition, since the first injection port and the second injection port having different positions in the rod diameter direction are provided, the diameter of cutting the ground by the injection of the chemical material from one injection port may be small. The amount of chemicals injected into the ground can be reduced. Thereby, the amount of mud is also reduced, and the cost required for the mud treatment can be reduced.

  In the present invention, at least one of the injection device and the stirring device is a mechanism that can rotate between a state protruding in the radial direction of the rod and a state along the longitudinal direction of the rod. When the ground improvement device is inserted into the ground, the injection device and the stirring device can be brought close to each other along the outer peripheral surface of the rod, so that the hole drilled from the ground surface to the ground In addition, when inserting the rod, the injection device and the stirring device do not hinder.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to form the ground improvement body with uniform distribution of a chemical | medical material, performing a wide range improvement with a small machine.

It is a side view which shows the state which opened the injection apparatus and stirring apparatus of the ground improvement apparatus which concern on 1st embodiment of this invention. It is a side view which shows the state which closed the injection apparatus and the stirring apparatus. It is an AA arrow line view of FIG. It is a figure which shows the injection device of a closed state by R arrow line view of FIG. It is a figure which shows the injection device of the closed state by L arrow line view of FIG. FIG. 4 is an enlarged view of the vicinity of the base end portion of the stirring blade, as viewed from the arrow R in FIG. FIG. 4 is an enlarged view of the vicinity of the base end portion of the stirring blade, as viewed in the direction of arrow L in FIG. 3. It is a BB arrow line view of FIG. FIG. 5 is a view taken along the arrow B′-B ′ in FIG. 4. It is a figure which shows the injection apparatus of the open state. It is CC arrow line view of FIG. It is an enlarged view of a stopper. It is a figure which shows the stirring apparatus of the closed state by the arrow R figure of FIG. It is a figure which shows the stirring apparatus of the closed state by L arrow line view of FIG. FIG. 4 is an enlarged view of the vicinity of the base end portion of the stirring blade, as viewed from the arrow R in FIG. FIG. 4 is an enlarged view of the vicinity of the base end portion of the stirring blade, as viewed in the direction of arrow L in FIG. 3. It is DD arrow line view of FIG. It is a D'-D 'arrow line view of FIG. It is a figure which shows the stirring apparatus of the open state. It is an EE arrow line view of FIG. It is an enlarged view of a stopper. It is a figure which shows the construction procedure using a ground improvement apparatus. It is a figure which shows the construction procedure using a ground improvement apparatus. It is a figure which shows the construction procedure using a ground improvement apparatus. It is a figure which shows the construction procedure using a ground improvement apparatus. It is a figure which shows the construction procedure using a ground improvement apparatus. It is a figure which shows the construction procedure using a ground improvement apparatus. It is a figure which shows the construction procedure using a ground improvement apparatus. It is a figure which shows the construction procedure using a ground improvement apparatus.

  Hereinafter, preferred embodiments of a ground improvement device according to the present invention will be described in detail with reference to the drawings.

  First, the overall configuration will be described.

  FIG. 1 is a side view showing a state in which the injection device 2 and the agitation device 3 of the ground improvement device 1 according to the first embodiment of the present invention are opened. Moreover, FIG. 2 is a side view which shows the state which closed the injection apparatus 2 and the stirring apparatus 3, and FIG. 3 is an AA arrow line view of FIG.

  As shown in FIGS. 1 to 3, the ground improvement device 1 includes a rod 4 having a first injection port 4 a for injecting a chemical material that is a grout material on the outer periphery, and a tip than the first injection port 4 a. The injection device 2 attached to the rod 4 at a position on the side, and the stirring device 3 attached to the rod 4 at a position further to the tip than the injection device 2 are provided.

  Next, the structure of the rod 4 will be described.

  A bit is attached to the tip of the rod 4. When the rod 4 is inserted into the ground E, the rod 4 is rotated and water is sprayed from the tip, and the ground E is excavated with a bit.

  A first check valve 4b is attached to the first injection port 4a, and the first check valve 4b opens when the pressure of the chemical material supplied into the rod 4 exceeds a predetermined value, and the medicine The material is injected from the first injection port 4a.

  The injection device 2 has the following structure.

  4 and 5 are views showing the injection device 2 in a closed state, respectively, as viewed from the arrows R and L in FIG. 3, and FIGS. 6 and 7 are views as seen from the arrows R and L, respectively, in FIG. FIG. 3 is an enlarged view of the vicinity of a base end portion of a stirring blade 2a. 8 and FIG. 9 are views taken along arrows BB and B′-B ′ in FIG. 4, respectively, and FIG. 10 is a view showing the injection device 2 in an opened state. 11 is a view taken along the line CC in FIG. 10, and FIG. 12 is an enlarged view of the stopper 5b.

  As shown in FIGS. 4 to 11, the injection device 2 includes a stirring blade 2 a provided so as to sandwich the rod 4. The stirring blade 2a is formed by connecting the blade 2p and the blade 2q with a connecting member 2c so as to sandwich the rod 4. In the present embodiment, plate-shaped steel materials are used as the blade 2p and the blade 2q.

  The wing 2p and the wing 2q have a pair of front and back arc-shaped grooves 2e provided at the base end thereof as a guide, and project in the radial direction of the rod 4 (that is, in an open state) and in the longitudinal direction of the rod 4 (A mechanism for rotation will be described later). When the wing 2p and the wing 2q rotate, the cutout portion 2i is provided on the side surface of the rod 4 so that the rod 4 does not hinder the movement range of the connecting member 2c.

  When the wing 2p is rotated downward about its base end from the open state, the wing 2q connected by the connecting member 2c is simultaneously moved upward about the base end. By rotating, each is in a closed state. Since the blade 2p is heavier than the blade 2q, the stirring blade 2a is closed by its own weight when no external force is applied.

  The injection device 2 includes an arcuate groove 2e at the base end portions of the blade 2p and the blade 2q, and includes an injection device rotation mechanism 5 for opening and closing the stirring blade 2a.

  The injection device turning mechanism 5 is fixed to the outer periphery of the rod 4 and is provided in a third opening portion 4d that is freely fitted in the groove 2e and that opens and closes the opening 4d that communicates the inside of the rod 4 and the groove 2e. The check valve 2k is provided on the outer periphery of the rod 4 and includes a stopper 5b for temporarily fixing the blade 2q to the rod 4.

  The third check valve 2k opens when the pressure of the chemical material in the rod 4 exceeds a predetermined value, and the chemical material is supplied into the groove 2e through the opening / closing hole 4d.

  When the chemical material in the rod 4 passes through the opening / closing hole 4d and is supplied into the groove 2e, the pressure of the chemical material acts on one end face 2f of the groove 2e, so that the blade 2p and the blade 2q are opened. Rotate.

  When the wing 2p and the wing 2q rotate around the base end and the protrusion 5a contacts the other end surface 2g of the groove 2e, the wing 2p and the wing 2q stop rotating and maintain their state. . At this time, the blade 2p and the blade 2q are in a substantially horizontal state. In the present embodiment, the circumferential length of the groove 2e is formed so that the rotational angle range of the blade 2p and the blade 2q is 90 °.

  As shown in FIG. 12, the stopper 5 b is installed in a hole 5 c formed in the outer peripheral portion of the rod 4 with which the closed wing 2 q contacts, and has a convex shape with its tip end outward from the outer periphery of the rod 4. The protrusion 5d includes a protrusion 5d and a spring 5e installed between the bottom of the hole 5c and the protrusion 5d. Further, a pilot hole 5g for transmitting the pressure in the rod 4 to the hole 5c is provided.

  When the pressure of the chemical material passing through the rod 4 is smaller than a predetermined value, the rod protrudes outward from the outer peripheral surface of the rod 4 and fits into the recess 2m of the blade 2q to suppress the rotation of the blade 2q. . On the other hand, when the pressure of the chemical passing through the rod 4 exceeds a predetermined value, the spring 5e contracts due to the pressure transmitted through the pilot hole 5g and the protrusion 5d is drawn inward from the outer peripheral surface of the rod 4. Then, the blade 2q is brought into a rotatable state.

  At the tips of the wing 2p and the wing 2q, a second injection port 2b for injecting a chemical material is provided. Further, the blade 2p and the blade 2q are each provided with a feed path 2d for feeding a chemical supplied through a feed hole 4c provided on the outer periphery of the rod 4 to the second injection port 2b. ing.

  A second check valve 2j is attached to the supply hole 4c, and the second check valve 2j opens when the pressure of the chemical material supplied into the rod 4 exceeds a predetermined value, and the chemical material is fed. Supplied to the path 2d.

  While the blade 2p and the blade 2q are rotated with the rotation of the rod 4, the drug material is injected from the second injection port 2b, thereby being injected and mixed with the drug material from the first injection port 4a. In addition, the ground E around the rod 4 can be forcibly stirred, and the outer peripheral portion can be further jet-mixed.

  The stirring device 3 has a structure shown below.

  FIGS. 13 and 14 are views of the agitator 3 in the closed state as viewed from the arrows R and L in FIG. 3, respectively, and FIGS. 15 and 16 are views as seen from the arrows R and L in FIG. 3, respectively. It is an enlarged view of the base end part vicinity of the stirring blade 3a. 17 and 18 are DD and D′-D ′ arrow views of FIG. 13, and FIG. 19 is a diagram showing the stirring device 3 in an opened state. 20 is an EE arrow view of FIG. 19, and FIG. 21 is an enlarged view of the stopper 6b.

  As shown in FIGS. 13 to 20, the stirring device 3 includes a stirring blade 3 a provided so as to sandwich the rod 4. The stirring blade 3a is formed by connecting the blade 3p and the blade 3q with a connecting member 3b so as to sandwich the rod 4. In the present embodiment, plate-shaped steel materials are used as the blades 3p and 3q. The longitudinal lengths of the blade 3p and the blade 3q are longer than those of the blade 2p and the blade 2q of the injection device 2.

  The wing 3p and the wing 3q have a pair of front and back arc-shaped grooves 3c provided at the base end thereof as a guide, and project in the radial direction of the rod 4 (that is, in an open state), and the longitudinal direction of the rod 4 (A mechanism for rotation will be described later). When the wing 3p and the wing 3q rotate, the cutout portion 3i is provided on the side surface of the rod 4 so that the rod 4 does not hinder the range in which the connecting member 3b moves.

  When the blade 3p is rotated downward about its base end from the opened state, the blade 3q connected by the connecting member 3b is simultaneously opened upward about the base end. By rotating, each is in a closed state. Since the blade 3p is heavier than the blade 3q, the stirring blade 3a is closed by its own weight when no external force is applied.

  The stirring device 3 has an arcuate groove 3c at the base ends of the blades 3p and 3q, and includes a stirring device rotating mechanism 6 for opening and closing the stirring blade 3a.

  The stirrer rotation mechanism 6 is fixed to the outer periphery of the rod 4 and is provided in a protrusion 6a loosely fitted in the groove 3c, and a fourth opening / closing hole 4e communicating the rod 4 and the groove 3c. The check valve 3j is provided on the outer periphery of the rod 4 and includes a stopper 6b for temporarily fixing the blade 3q to the rod 4.

  The fourth check valve 3j opens when the pressure of the chemical material in the rod 4 exceeds a predetermined value, and the chemical material is supplied into the groove 3c through the opening / closing hole 4e.

  When the chemical material in the rod 4 passes through the opening / closing hole 4e and is supplied into the groove 3c, the pressure of the chemical material acts on one end surface 3f of the groove 3c, so that the blade 3p and the blade 3q are opened. Rotate.

  When the wing 3p and the wing 3q rotate around the base end and the protrusion 6a contacts the other end surface 3g of the groove 3c, the rotation of the wing 3p and the wing 3q stops and maintains that state. . At this time, the blade 3p and the blade 3q are in a substantially horizontal state. In the present embodiment, the circumferential length of the groove 3c is formed so that the rotational angle range of the blade 3p and the blade 3q is 90 °.

  As shown in FIG. 21, the stopper 6 b is installed in a hole 6 c formed in the outer peripheral portion of the rod 4 with which the closed wing 3 q contacts, and has a convex shape with its tip end outward from the outer periphery of the rod 4. The protrusion 6d is configured to protrude and a spring 6e installed between the bottom of the hole 6c and the protrusion 6d. A pilot hole 6g for transmitting the pressure in the rod 4 to the hole 6c is provided.

  When the pressure of the chemical material passing through the rod 4 is smaller than a predetermined value, the rod protrudes outward from the outer peripheral surface of the rod 4 and fits into the recess 3m of the blade 3q to suppress the rotation of the blade 3q. . On the other hand, when the pressure of the chemical passing through the rod 4 exceeds a predetermined value, the spring 6e contracts due to the pressure transmitted through the pilot hole 6g, and the protrusion 6d is drawn inward from the outer peripheral surface of the rod 4. Then, the blade 3q is brought into a rotatable state.

  By rotating the blade 3p and the blade 3q with the rotation of the rod 4, the ground where the chemicals injected from the first injection port 4a and the second injection port 2b are present is forcibly stirred. Can do.

  Next, ground improvement using the ground improvement device 1 will be described.

  22-29 is a figure which shows the construction procedure using the ground improvement apparatus 1. FIG. In these figures, the hatched portion of the left-downward inclined line indicates the range in which the chemical mixture is injected and mixed, and the cross-shaped hatched portion indicates the range in which the injected and mixed range is stirred and mixed with the stirring blades. .

  First, as shown in FIG. 22, the ground E is drilled to a predetermined depth while spraying water from the tip of the rod 4. The injection pressure of the drilling water at this time is, for example, 5 MPa, but is not limited to this value, and may be smaller than the value at which the first check valve 4b is opened.

  Then, as shown in FIG. 23, when a hole is drilled to a predetermined depth, the steel ball 7 is dropped into the rod 4 and the tip of the rod 4 is closed.

  Next, as shown in FIG. 24, when the chemical material is supplied into the rod 4 and the pressure in the rod 4 is maintained at 10 MPa, the first check valve 4b is opened and the chemical material is supplied from the first injection port 4a. Be injected. In this manner, the chemical material is injected and mixed in the ground E around the rod 4 by pulling up the rod 4 while rotating the rod 4 while injecting the chemical material from the first injection port 4a.

  Next, as shown in FIG. 25, the tip of the blade 2p located on the lower side of the closed stirring blade 2a reaches the lower end depth of the jet-mixed region (the hatched portion of the left downward inclined line in the figure). When the rod 4 is lifted by a distance until it reaches (corresponding to the first predetermined distance of claim 1), the rotation and the pulling are stopped, and then the pressure in the rod 4 is increased. When the pressure in the rod 4 reaches 15 MPa, the stopper 5b is released.

  After that, when the pressure is continuously increased and the pressure in the rod 4 reaches 20 MPa, as shown in FIG. 26, first, the fourth check valve 3j is opened and the stirring blade 2a of the injection device 2 begins to open. When the pressure in the rod 4 reaches 22 MPa, the second check valve 2j is also opened, and the chemical material is injected from the second injection port 2b.

  The lengths of the blade 2p and the blade 2q are set to be approximately equal to the radius of the jet stirring from the first injection port 4a.

  As shown in FIG. 27, while the stirring blade 2a of the injection device 2 is opened, the drug substance is injected from the first injection port 4a and the second injection port 2b, and the rod 4 is pulled up while rotating. In addition, the ground E can be jet-mixed to a large diameter outside the stirring blade 2a, and the ground within the stirring blade 2a can be mechanically stirred.

  Then, the distance until the tip of the lower blade 3p of the closed stirring blade 3a reaches the lower end depth of the mechanically stirred region (cross-shaped hatched portion in the figure). When the rod 4 is lifted by a predetermined distance), the rotation and pulling are stopped, and then the pressure in the rod 4 is increased. When the pressure in the rod 4 reaches 24 MPa, the stopper 6b is released.

  After that, when the pressure is continuously increased and the pressure in the rod 4 reaches 25 MPa or more, the fourth check valve 3j is opened and the stirring blade 3a of the stirring device 3 is opened as shown in FIG. The lengths of the blade 3p and the blade 3q are set to be approximately equal to the radius of the jet stirring from the second injection port 2b. In the state where the stirring blade 2a of the injection device 2 and the stirring blade 3a of the stirring device 3 are opened, the chemical material is injected from the first injection port 4a and the second injection port 2b, and the rod 4 is pulled up while rotating. As a result, the ground E can be jetted and mixed to a large diameter outside the stirring blade 2a, and the target ground can be mechanically stirred to form a uniform ground improvement body.

  Then, when the ground is improved within a predetermined range while pulling up the rod 4, the rotation of the rod 4 is stopped and the supply of the chemical material into the rod 4 is stopped. When the pressure in the rod 4 decreases due to the stop of the supply of the chemical material into the rod 4, as shown in FIG. 29, when the heavy wings 2p and 3p are rotated downward naturally by their own weight from the open state. At the same time, the blades 2q and 3q connected by the connecting members 2c and 3b rotate upward, so that the injection device 2 and the stirring device 3 are closed. The injection device 2 and the stirring device 3 are closed, and the rod 4 is pulled up to the ground.

  According to the above-described embodiment, since the agitating blade 2a of the injection device 2 includes the second injection port 2b at the projecting end portion, even with the same injection pressure, injection mixing with a chemical material is performed to a larger diameter range. be able to. Moreover, since the wing 3p and the wing 3q of the stirring device 3 projecting to the jet mixing range from the tip of the wing 2p and the wing 2q are provided, in addition to the ground agitated by the jet from the first jet port 4a The ground which has been jetted and stirred by jetting from the second jetting port 2b can also be stirred. Therefore, since the uniform mixture of a chemical | medical material and soil can be created in the ground E with a large diameter, a reliable ground improvement body can be formed in a wide range. Further, the inside of the ground injected and mixed by the injection from the first injection port 4a is agitated by the stirring blade 2a, and the inside of the ground injected and mixed by the injection from the second injection port 2b is stirred by the stirring blade 3a. Thus, since the rotational resistance during rotation of both stirring blades 2a and 3a is reduced, the rotational torque required to rotate both stirring blades 2a and 3a may be small. Thereby, the ground improvement apparatus 1 main body can be reduced in size.

  In addition, by providing the first injection port 4a and the second injection port 2b at different positions in the rod diameter direction, the diameter of cutting the ground E by the injection of the chemical material from each injection port is small. Since it is good, the injection amount of the chemical material to the ground E can be reduced. Thereby, the amount of mud is also reduced, and the cost required for the mud treatment can be reduced.

  Since the agitating blade 2a and the agitating blade 3a are rotatable, by rotating them so that they are closed, the amount of protrusion of the agitating blade 2a and the agitating blade 3a from the outer peripheral surface of the rod 4 is very small. can do. Therefore, when the rod 4 is inserted into the hole drilled in the ground E from the ground surface, the stirring blade 2a and the stirring blade 3a do not hinder.

  The operating pressures of the first to fourth check valves 2j, 2k, 3j, 4b, the stirring blades 2a, 3a, and the stoppers 5b, 6b are not limited to the above-described values, Accordingly, it is appropriately determined depending on the design.

  In the present embodiment, the case where only one stage of the injection device 2 is provided has been described, but a plurality of stages may be provided. And in the case where the injection device 2 is provided in a plurality of stages, it is possible to reduce the injection pressure of the chemical material and reduce the amount of injection from each of the injection devices 2, so that the amount of excess mud is reduced, Waste disposal costs can be reduced.

  In the present embodiment, the wing 2p and the wing 2q are described as rotating the wing 3p and the wing 3q in different directions. However, the present invention is not limited to this, and the wing 2p and the wing 2q are rotated in the same direction. Also good.

  In the present embodiment, the stirring blade 2a and the stirring blade 3a use a mechanism that protrudes by rotation, but the present invention is not limited to this, and a hollow hose-like structure may be considered. It is done. In this case, the stirring blade 2a and the stirring blade 3a are in a state along the longitudinal direction of the rod 4 when the chemical material is not supplied into the hose. The hose stands up due to the injection pressure and protrudes in the radial direction of the rod 4.

DESCRIPTION OF SYMBOLS 1 Ground improvement apparatus 2 Injection apparatus 2a Stirring blade 2b 2nd injection port 2c Connecting material 2d Feeding path 2e Groove 2f One end surface 2g The other end surface 2i Notch part 2j 2nd check valve 2k 3rd check valve 2m Recess 2p Blade 2q Blade 3 Stirring device 3a Stirring blade 3b Connecting material 3c Groove 3f One end surface 3g The other end surface 3i Notch 3j Fourth check valve 3m Recess 3p Blade 3q Blade 4 Rod 4a First injection port 4b First 1 check valve 4c supply hole 4d opening / closing hole 4e opening / closing hole 5 jetting device turning mechanism 5a protrusion 5b stopper 5c hole 5d protrusion 5e spring 5g pilot hole 6 stirring device turning mechanism 6a protrusion 6b stopper 6c hole 6d Protrusion 6e Spring 6g Pilot hole 7 Steel ball E Ground

Claims (3)

A rod having a first injection port on the outer periphery for injecting a chemical material for improving the ground, and a predetermined length in the radial direction of the rod at a position closer to the tip than the first injection port of the rod And an injection device having a second injection port for injecting the chemical material at the protruding end, and a rod diameter longer than the injection device at a position closer to the tip than the injection device of the rod. A step of inserting the rod from the ground up to a predetermined depth in the ground, with the jetting device and the stirring device of the ground improvement device provided with a stirrer protruding in the direction in a state along the longitudinal direction of the rod When,
A step of pulling up the rod to a first predetermined distance while injecting a chemical from the first injection port;
A step of causing the injection device to protrude in a radial direction of the rod while injecting a chemical from the first injection port;
Raising the rod to a second predetermined distance while stirring the ground by the spray device;
A step of projecting the stirring device in a radial direction of the rod while injecting a chemical from the first injection port and the second injection port;
And a step of pulling up the rod by a predetermined distance while stirring the ground with the spray device and the stirring device. A ground improvement device that improves the ground by injecting and stirring chemicals on the ground,
A rod having a first injection port on the outer periphery for injecting the chemical material;
A second injection port for injecting the medicinal material is provided at the tip end side of the first injection port of the rod so as to protrude by a predetermined length in the radial direction of the rod. An injection device in the part;
A stirrer for agitating the ground, provided at a position on the tip side of the ejector of the rod so as to protrude in the radial direction of the rod longer than the ejector. To improve the ground.   At least one of the injection device and the stirring device includes a mechanism that can rotate between a state protruding in the radial direction of the rod and a state along the longitudinal direction of the rod. The ground improvement device according to claim 2.

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