JP3956171B2 - Ground improvement method and ground improvement equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a ground improvement method for improving the ground by attaching a stirring head having an improvement material discharge port to the top and bottom of the rod body at the tip of the excavation rod, and switching the discharge port to stir and mix the improvement material and soil. It relates to the device.
[0002]
[Prior art]
For example, Japanese Patent Publication No. 5-62167 and Japanese Patent Publication No. 6-39779 have been disclosed as techniques for improving the ground by switching the upper and lower discharge ports provided in the stirring head and discharging the improvement material.
However, both of these techniques have a problem that the agitation head has a double-pipe structure, so that the structure becomes complicated and the apparatus becomes large.
[0003]
[Problems to be solved by the invention]
Japanese Laid-Open Patent Publication No. 6-146267 has been proposed as a discharge switching device for a single-tube stirring head. This device is configured so that the upper and lower agitating blades are covered with an upper housing and a lower housing, respectively, and each housing moves up and down by a certain stroke relatively, but the device becomes larger and heavier. Penetration resistance will increase, and problems such as inability to penetrate depending on the soil will not be solved.
[0004]
Furthermore, there is a method of switching the discharge port by forward / reverse rotation of the stirring head, but since this method limits the rotation direction of the stirring head, it can be applied by using forward / reverse rotation of the stirring head at the time of construction. There is a problem that it cannot be done.
In addition, none of the conventional techniques has a means for confirming whether or not the upper and lower discharge ports are appropriately switched.
[0005]
The present invention has been made to solve these problems, and whether or not the discharge port of the improved material is switched by the upper and lower discharge port switching mechanism having a simple structure, and whether or not the discharge port is appropriately switched. It is to provide a ground improvement method for improving the ground while confirming the above and a device used therefor.
[0006]
[Means for Solving the Problems]
In order to solve these problems, the present invention is provided with a plurality of stirrer blades attached to a rod body of a hollow rod having an improved material flow passage, and improved material discharge ports provided at the upper and lower portions of the rod body. In the ground improvement method for improving the ground by stirring and mixing the improvement material discharged from the discharge port of the stirring head of the ground improvement device attached to the tip of the excavation rod and the soil, the stirring head of the ground improvement device is A single-pipe structure with an upper discharge port at the upper part of the rod body of the stirring head and a lower discharge port at the lower part, and an upper and lower discharge port switching mechanism that utilizes the difference in earth pressure that acts when the rod is inserted and pulled up An improved material is provided on the rod body, and the improved material is discharged from the lower discharge port when the rod is inserted by the discharge port switching mechanism and from the upper discharge port when the rod is lifted. The soil was mixed and stirred, a ground improvement method to improve the soil.
[0007]
Further, a stirrer head provided with a plurality of stirrer blades in a rod body of a hollow rod having an improved material flow passage, and a discharge head communicating with the improved material flow passage respectively provided in the upper and lower portions of the rod body, the tip of the excavation rod In the ground improvement device attached to the section, the stirring head has a single tube structure, and a switching blade is attached to the rod body so that it can be moved up and down by a certain distance by earth pressure acting when the rod is inserted and pulled up. the stop valve provided in the connecting rod of the wing, at the time of intrusion in communication with the lower portion discharge port improved material flow path, at the time of the rod pulling the upper and lower discharge port switching mechanism for closing an improved material flow path of the lower discharge port of the upper stirring blade The ground improvement device is provided with a check valve provided at the upper part and provided with a check valve that opens at a certain fluid pressure or higher at the upper discharge port.
[0008]
Further, excavating the stirring head provided with a plurality of stirrer blades in the rod body of the hollow rod having the improved material flow passage and provided with the improved material discharge ports communicating with the improved material flow passage in the upper and lower portions of the rod body, respectively. In the ground improvement device attached to the tip of the rod, the stirring head has a single tube structure, and a switching blade having a connecting rod at a position deviated from the center position in the width direction of the blade body is provided with an upper stirring blade of the rod body. The passage of the passage switching valve having two passages with different diameters, which are interposed in the improvement material flow passage by turning of the switching blade and the connecting rod when the rod is inserted, is inserted in the upper part of the rod. It is a ground improvement device provided with a vertical discharge port switching mechanism that is sometimes communicated to the lower discharge port and to the upper discharge port when the rod is lifted.
[0009]
It is a ground improvement device that confirms the switching of the upper and lower discharge ports by reading the scale of the pressure gauge of the injection pump.
[0010]
Since the present invention has the above configuration. The following effects are produced.
(1) Since the stirring head body has a single tube structure, the structure is simple and the handling is easy.
(2) Since the upper and lower discharge ports are switched by the vertical movement of the stirring head, the discharge ports can be switched regardless of the rotation direction of the stirring head.
(3) Since a drive (power) source is not required to switch the upper and lower discharge ports, it is economical.
(4) Check whether the upper and lower discharge ports are properly switched by reading the pressure gauge of the infusion pump by providing a check valve that opens above the fluid pressure at the upper discharge port. Can do.
(5) By using a passage switching valve having two passages with different diameters for switching to the upper and lower discharge ports. It is possible to confirm whether the upper and lower discharge ports are appropriately switched by reading the pressure gauge of the infusion pump.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below based on examples.
FIG. 1 is an overall front view of a stirring head of a ground improvement device used in a ground improvement method according to claim 1 of the present invention. The stirring head 1 of the improved apparatus has a rod body 2 having a single tube structure, a plurality of stirring blades 6 and 7 projecting from the rod body 2, and an upper discharge port 3 at the upper part of the rod body. The lower discharge ports 4 are respectively provided, and the upper and lower discharge port switching mechanisms 20 and 20a shown in FIGS.
[0012]
The improved material upper / lower outlet switching mechanism 20 has the following configuration.
As shown in FIG. 2, a switching blade 5 is provided above the upper stirring blade 6 (not shown in FIG. 2) provided at the lower portion of the upper discharge port 3 of the rod body 2 having the improved material flow passage 11.
This switching blade 5 is connected by a stop valve 9 and a connecting rod 8 which are disposed in a part of the diameter-enlarging portion 11a of the improved material flow passage 11 of the rod body 2, and is connected to the switching blade 5 when the rod is inserted or pulled up. The rod body 2 is attached so as to be movable up and down by a predetermined distance in the vertical direction of the rod body 2 by the earth pressure acting.
The upper discharge port 3 is provided with a check valve 10 that opens at a certain fluid pressure or higher.
The stirring head 1 configured as described above is attached to a drilling rod (not shown) and penetrates into the ground while rotating the drilling rod. In this case, since upward earth pressure acts on the stirring head 1, the switching blade 5 attached to the rod body 2 so as to be movable up and down by a predetermined distance is pushed up to the upper end position (position indicated by a solid line in FIG. 2). Stop.
[0014]
At this time, the stop valve 9 attached to the connecting rod 8 connected to the switching blade 5 rises in the partial diameter enlarged portion 11a of the improved material flow passage 11 as the switching blade 5 rises. When stopping at the upper end position, the stop valve 9 also stops with the improved material flow passage 11 in communication with the lower discharge port 4. In this case, the upper discharge port 3 is also communicated, but the discharge of the improved material is reverse because it is discharged from the lower discharge port 4 at a pressure lower than the fluid pressure at which the check valve 10 provided at the upper discharge port opens. No discharge is made from the upper discharge port 3 by the action of the stop valve 10.
Thus, after excavating and stirring to a predetermined depth while discharging the improved material from the lower discharge port 4, the excavating rod is pulled up while rotating.
[0015]
In the case of rotating the excavating rod, since a downward earth pressure opposite to that when penetrating acts on the stirring head 1, the switching blade 5 is pushed down to the lower end and stops. (Position indicated by dotted line in FIG. 2).
At this time, the stop valve 9 is also lowered and stopped in a state where it is fitted to the improved material flow passage 11, the improved material flow passage 11 b to the lower discharge port is closed, and the improved material flow passage 11 is connected to the upper discharge port 3. Communicate.
In this state, the improvement material is discharged from the upper discharge port 3 by the fluid pressure at which the check valve 10 provided at the upper discharge port 3 opens, and the excavation rod is rotated to improve the ground.
[0016]
In order to prevent inflow of earth and sand into the lower discharge port 4, a check valve that opens at a pressure equal to or lower than the fluid pressure at which the check valve 10 of the upper discharge port 3 opens may be provided.
Whether or not the upper and lower discharge ports 3 and 4 are appropriately switched is confirmed by reading the pressure gauge of the infusion pump (not shown). That is, when the improving material is discharged from the upper discharge port 3, the reading of the pressure gauge shows a value equal to or higher than the pressure value at which the check valve 10 of the upper discharge port 3 opens and is discharged from the lower discharge port 4. If it is, the value below that is shown.
In the embodiment, the shape of the stop valve 9 is spherical. However, the shape is not limited to this, and various shapes such as a conical shape are conceivable.
[0017]
Next, an embodiment of the ground improvement device according to claim 3 and a construction method using the same will be described.
As shown in FIG. 3, the switching blade 5a is attached to the rod body 2 by the connecting rod 8a at a position deviated from the center position in the width direction of the blade body. As shown in FIG. 5, a passage switching valve 12 having passages 13a and 13b having different diameters is interposed in the middle of the improvement material flow passage 11 inside the rod body. The diameter of the passage switching valve 12 is different. An upper / lower discharge port switching mechanism 20a having a structure in which the improved material flow passage 11 communicates with the upper discharge port 3 and the lower discharge port 4 by switching between the two passages (13a, 13b) is provided.
The passage switching of the passage switching valve 12 is performed by turning the switching blade 5a and the connecting rod 8a (see FIG. 4).
[0018]
The agitation head configured as described above is attached to an excavation rod (not shown), and penetrates into the ground while rotating the excavation rod. In this case, since the upward earth pressure acts on the stirring head, the switching blade 5a and the connecting rod 8a rotate around the connecting rod to the position shown by the solid line in FIG. As shown in FIG. 5A, the improved material flow passage 11 communicates with the lower discharge port 4 through the large-diameter passage 13 a of the passage switching valve 12.
[0019]
In this state, after the improvement material is discharged from the lower discharge port 4 and excavated and stirred to a predetermined depth, the excavating rod is pulled up while rotating. In this case, since the downward earth pressure acts on the stirring head, the switching blade 5a and the connecting rod 8a rotate about the connecting rod to the position indicated by the dotted line in FIG. As shown in FIG. 5B, the improvement material passage 11 is communicated with the upper discharge port 3 by the small diameter passage 13 b of the passage switching valve 12.
In this state, the improvement material is discharged from the upper discharge port 3, and the excavation rod is rotated and pulled up to improve the ground.
[0020]
Whether the upper and lower discharge ports are properly switched is confirmed by reading the pressure gauge of the infusion pump. That is, when the improved material is discharged from the upper discharge port, the improved material is communicated through the small-diameter passage 13b of the passage switching valve 12, so that the discharge from the lower discharge portion 4 communicated through the large-diameter passage 13a of the passage switching valve 12 is performed. Pressure gauge readings are higher than sometimes.
When the upper discharge port 3 is communicated with the large-diameter passage 13a and the lower discharge port 4 is communicated with the small-diameter passage 13b, when the improving material is discharged from the upper discharge port 3, the pressure is higher than when discharging from the lower discharge port 4. The gauge reading shows a low value.
[0021]
As seen in the above embodiments, the method and apparatus of the present invention can efficiently stir and mix the improving material and the soil with all the stirring blades in a plurality of stages both when the excavation rod is inserted and when it is pulled up.
In this embodiment, a switching blade is separately provided on the upper part of the upper stirring blade. Of course, this switching blade has the function of a stirring blade, and the upper stirring blade is used as a switching blade. Of course, it can be configured.
[0022]
In addition, the construction method of the present invention is not limited to the mechanical stirring method, and can be sufficiently applied to the switching of chemical flow paths in various fields such as high-pressure injection, horizontal improvement, and chemical injection.
[0023]
【The invention's effect】
As a result of the ground improvement by the ground improvement method according to the present invention, it is possible to confirm the effects as described in the action section of the present specification, obtain an improved body of uniform quality, and obtain a desired improvement effect. I was able to.
[Brief description of the drawings]
FIG. 1 is a front view of an entire stirring head used in a ground improvement method according to the present invention.
FIG. 2 is a schematic sectional view of a main part of an upper / lower discharge port switching mechanism of a stirring head according to claim 2;
3 is a schematic cross-sectional view of a main part of an upper and lower discharge port switching mechanism of a stirring head according to claim 3. FIG.
FIG. 4 is a schematic view showing a rotating state of the switching blade and the connecting rod according to claim 3;
FIG. 5 is a schematic view showing an operating state of a passage switching valve of an upper and lower discharge port switching mechanism according to claim 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Stirring head 2 Head main body 3 Upper discharge port 4 Lower discharge port 5 Switching blade 5a Switching blade 6 Upper stirring blade 7 Stirring blade 8 Connecting rod 8a Connecting rod 9 Stop valve 10 Check valve 11 Improved material flow passage 11a Partial diameter expansion Part 12 Passage switching valve 13 Passage switching valve passage 20 Vertical discharge port switching mechanism 20a Vertical discharge port switching mechanism

Claims (4)

A ground where a plurality of stirrer blades are attached to a rod body of a hollow rod having an improved material flow passage, and an agitation head provided with improved material discharge ports at the upper and lower portions of the rod body is attached to the tip of a drilling rod. In the ground improvement method for improving the ground by stirring and mixing the improved material discharged from the discharge port of the stirring head of the improved device and the soil, the stirring head of the ground improving device has a single pipe structure, and the rod body of the stirring head An upper discharge port is provided at the upper part and a lower discharge port is provided at the lower part, and an upper and lower discharge port switching mechanism that utilizes the difference in earth pressure acting when the rod is inserted and pulled up is provided above the upper stirring blade of the rod body . provided a check valve which opens on one fluid pressure or the upper discharge port, from the lower discharge port at the time of rod penetrated by the vertical discharge port switching mechanism, at the time of rod pulled up from the upper discharge opening The discharge of each of the modifying material, if the improvement material is discharged from the upper discharge port, the pressure reading gauge indicates a value of more than the pressure value check valve of the upper discharge opening is opened, discharged from the lower discharge port The ground is characterized by improving the ground by confirming the switching of the upper and lower discharge ports by reading the pressure gauge of the infusion pump by showing a value less than that, and stirring and mixing the improvement material and the soil. Improved construction method. A hollow rod having an improved material flow passage is provided with a plurality of stirrer blades on the rod body, and an agitation head provided with discharge ports communicating with the improved material flow passage at the upper and lower portions of the rod body is provided at the tip of the excavation rod. In the attached ground improvement device, the stirring head has a single-pipe structure, and a switching blade is attached to the rod body so that it can move up and down by a certain distance by earth pressure acting when the rod penetrates and pulls up. the stop valve provided in the connecting rod, at the time of intrusion in communication with the lower portion discharge port improved material flow path, at the time of the rod pulling the upper and lower discharge port switching mechanism for closing an improved material flow path of the lower discharge opening at the top of the upper stirring blade A ground improvement device provided with a check valve that opens at an upper discharge port at a certain fluid pressure or higher. A hollow rod having an improved material flow passage is provided with a plurality of stirrer blades on the rod body, and an improved material discharge port communicating with the improved material flow passage is provided at the upper and lower portions of the rod body. In the ground improvement device attached to the section, the stirring head has a single tube structure, and a switching blade having a connecting rod at a position deviated from the center position in the width direction of the blade body is provided above the upper stirring blade of the rod body. The passage of the passage switching valve having two passages with different diameters inserted in the improved material flow passage by the rotation of the switching blade and the connecting rod accompanying the attachment, penetration of the rod, and pulling up, the lower discharge port when the rod penetrates In addition, the ground improvement device is provided with a vertical discharge port switching mechanism that communicates with the upper discharge port when the rod is lifted. Ground improvements apparatus according to claim 2-3, wherein the performing by the scale reading of the pressure gauge infusion pump confirmation of upper and lower discharge port of the switching.

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