JPS641606B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention involves drilling a pilot hole in the ground and then injecting high-pressure water in the horizontal direction to form a cylindrical cavity in the ground. The present invention relates to a ground modification device suitable for application to a ground modification method in which a new ground is formed by pouring a soil improving agent such as concrete into a hollow cavity.

(b) Background of the technology When constructing an artificial ground, a cavity is excavated underground and the hollow part is replaced with a ground improvement agent such as concrete, resulting in the construction of a solid plate-shaped artificial ground underground. A construction method has been proposed to
133918, JP 58-24020, JP 58-26115, JP 58-20819, etc.).

In this method, the ground is excavated by injecting ultra-high pressure water from a nozzle. However, as the distance from the nozzle to the wall of the cavity to be excavated increases as excavation progresses, the excavation ability of ultra-high pressure water decreases. It will drop.

(c) Prior art and problems Therefore, in order to solve these problems,
In 58-24020, in addition to the normal nozzle, another nozzle is installed at the tip of the rotatable stirring blade, and when the diameter of the cavity is small, drilling is performed with the normal nozzle, and when the diameter of the cavity increases, it When it becomes difficult to demonstrate sufficient excavation ability with the conventional nozzles, a method has been proposed in which the stirring blade is rotated and opened, and the nozzle at the tip is used to perform excavation. This method requires two types of nozzles, one for short-distance excavation and one for long-distance excavation, which has the disadvantage of complicating the structure of the soil modification device. Since it is stored along the axis of the tube and is spread out like an umbrella when in use, the height of the cavity must be sufficient for the rotation of the stirring blades, and if the cavity is too flat, However, there was an inconvenience that the stirring blade could not be rotated from the stored position, making it impossible to excavate.

Another possibility is to use a conventional nozzle to simply increase the jetting pressure of drilling water, but the pressure of drilling water is still several hundred atmospheres,
In order to further improve this, there was a drawback that incidental equipment such as pumps and high-pressure liquid supply pipes had to be larger and more precise.

Furthermore, FIG. 6 shows another conventional proposal example. This method uses a single nozzle 17 to
Although this method requires only one nozzle 17, the discharge direction of the nozzle 17 is not fixed and draws an arc, so the excavation is carried out in this way. The bottom of the cavity 32 also has an arcuate shape, resulting in the need for corrective excavation after excavation of the cavity 32, resulting in process waste.

(d) Purpose of the Invention In order to solve the above-mentioned drawbacks, the present invention is capable of excavating a large-diameter cavity with a single nozzle, regardless of the flat shape of the cavity, and also requires small incidental equipment such as a pump. The first objective is to provide a ground remodeling device that can be used in a variety of situations, and the second objective is to provide a ground remodeling device that can maintain a constant nozzle discharge direction.

(e) Configuration of the Invention That is, the present invention is configured such that a nozzle is provided on an excavation pipe through a parallel movement mechanism so that it can be freely projected and moved in the horizontal direction, and the discharge direction of the nozzle is always constant.

(f) Embodiments of the invention Hereinafter, embodiments of the invention will be specifically described based on the drawings.

Fig. 1 is a front view showing one embodiment of the ground modification device according to the present invention, Fig. 2 is an enlarged front view of the vicinity of the nozzle of the ground modification device shown in Fig. 1, and Fig. 3 is an enlarged front view of the nozzle shown in Fig. 2 extended. FIG. 4 is an enlarged front view showing another embodiment of the present invention, and FIG. 5 is an enlarged front view when the nozzle of FIG. 4 is extended.

As shown in FIG. 1, the ground modification device 1 includes a mobile heavy machine 2 such as a crawler crane, and the mobile heavy machine 2 is provided with a driver's seat 2a, crawlers 2b, 2b, and the like. Further, a columnar leader 3 is erected on the mobile heavy equipment 2 via a support frame 5, and a guide rail 3a is formed on the leader 3 in the vertical direction in the figure. A drilling pipe holding and rotating device 6 is provided on the guide rail 3a so as to be able to move up and down, and one end of a wire 7, the other end of which is wound around a winch (not shown), is connected to the drilling pipe holding and rotating device 6. has been done. Therefore, by driving the winch in the forward and reverse directions to pay out or retract the wire 7, the excavation pipe holding and rotating device 6 moves in the up and down direction along the guide rail 3a of the leader 3, that is, in the direction of arrows C and D.
You can move freely in any direction.

The excavation pipe holding and rotation device 6 is provided with a chuck 9 rotatable in the directions of arrows A and B by a rotary drive means 10 such as a motor built in the excavation pipe holding and rotation device 6. drilling pipe 15
A hollow cylindrical rod 13 constituting the rod 13 is installed through the rod 13 so as to be able to be gripped and fixed, and flanges 13a, 13a for connection are formed at both upper and lower ends of the rod 13. A plurality of rods 13 are connected in series at the lower part of the rod 13 in FIG.
Even if the rod rotates forward or backward in the directions of arrows A and B, each rod 13
There is no possibility that the connection between the two will become loose as would occur with a screw connection. The lower end of the excavation pipe 15 forms an opening 15a open to the outside, and an excavation bit 16 is attached to the lower end. Further, an ultrasonic ranging sensor 19 and a parallel movement mechanism 41 are provided slightly above the bit 16. As shown in FIG. 2, the parallel movement mechanism 41 includes a plurality of links 41a, 41b, 41c, 41
d, and a hydraulic jack 41e is provided between the rotation center of the links 41a and 41b and the rotation center of the links 41c and 41d, and the tips of rams 41f and 41f are pivotally mounted so as to be able to protrude from both the upper and lower sides. It is set in. A nozzle 17 is pivotally attached to the left end of the links 41b and 41d in the figure with its discharge port 17b facing horizontally, and a flexible high-pressure liquid supply pipe 20 is connected to the nozzle 17. ing. The high-pressure liquid supply pipe 20 is extended along the outer circumference of the excavation pipe 15 in the axial direction of the excavation pipe 15, that is, upward in FIG. There, it is connected to a flexible tube 22 having flexibility.
On the other hand, a flexible tube 25 that is similarly flexible is connected to the upper end of the excavation pipe 15.

Since the ground modification device 1 has the above configuration, in order to construct an artificial ground using the soil modification device 1, first move the excavation pipe holding and rotating device 6 along the guide rail 3a of the leader 3 in the direction of arrow C. Pull up,
The rotation drive means 10 in the excavation pipe holding and rotation device 6 is driven to rotate the chuck 9, for example, in the A direction. When the chuck 9 rotates, the excavation pipe 15 held by the chuck 9 also rotates in the direction A, and the excavation pipe 1
The bit 16 at the tip of 5 starts digging downward in FIG. 1 due to the weight of the excavation pipe holding and rotation device 6 and the excavation pipe 15. The excavation pipe holding and rotating device 6 is the leader 3
As the excavation pipe 15 and therefore the bit 16 move downward along
Pilot hole 2 as the trajectory of bit 16 in the direction
6 is excavated and formed. The pilot hole 26 is supplied with muddy water 27, and its hydrostatic pressure causes the pilot hole 2 to
6 from collapsing, the muddy water 27 in the pilot hole 26 is slurried together with the excavated earth and sand generated by the bit 16 through the flexible tube 25 by a suction pump (not shown), and is then pumped into the excavation pipe from the excavation pipe opening 15a. It is sucked up and discharged to the outside of the pilot hole 26 through each rod 13 inside 15. The discharged muddy water 27 is returned to the pilot hole 26 after separating the suctioned earth and sand, and is continuously used for excavation.

During excavation, the chuck 9 that rotationally drives the excavation pipe 15 continues to excavate by repeating accurate and reverse rotations within a 360° angle range by the rotation drive means 10, but the excavation pipe 15 cannot rotate more than 360°. Therefore, the muddy water 27 is discharged from the flexible tube 25 which is fixedly connected to the upper part of the excavation pipe 15 via the flange 13a.
It is done smoothly without giving extreme twist to 5.

Note that while the pilot hole 26 is being drilled, the hydraulic jack 41e of the parallel motion mechanism 41 has its rams 41f and 41f both extended as shown in FIG. is in a state in which the nozzle 17 is folded toward the excavation pipe 15 side. In this state, the distance L1 from the tip of the nozzle 17 to the axis of the drilling pipe 15 is smaller than the radius of the pilot hole 26. This is done smoothly without contacting the wall surface of the pilot hole 26.

In this way, the pilot hole 26 is excavated to a certain depth, and when the excavation pipe holding rotary device 6 reaches below the leader 3, the driving of the rotary drive means 10 is stopped to stop the excavation operation, and the excavation by the chuck 9 is stopped. The grip on the pipe 15 is stopped, the flexible tube 25 at the upper end of the excavation pipe 15 is removed, and the rod 13 is newly connected. Therefore, only the excavation pipe holding and rotating device 6 was pulled up in the C direction along the leader 3, and
The excavation pipe 15 is gripped via the newly connected rod 13 portion. Next, the flexible tube 25 is fixedly connected to the upper end of the newly connected rod 13, and in this state, the excavation tube holding and rotating device 6 is connected again.
The pilot hole 26 is rotated by driving the rotary drive means 10 of the
Start excavation. In this way, the pilot hole 26
is gradually formed in the D direction, and when the depth reaches DP, the excavation by the bit 16 is stopped and the excavation pipe holding rotation device 6 is pulled up together with the excavation pipe 15 by L1. Therefore, this time, ultra-high pressure water 29 is ejected from the flexible tube 22 from the nozzle 17 via the high-pressure liquid supply pipe 20. At this time, as the excavation pipe holding and rotating device 6 is gradually lowered in the D direction and the excavation pipe 15 is rotated back and forth through 360 degrees in the forward and reverse directions in the same manner as described above, ultra-high pressure water is generated in the ground 31. 29 forms a cylindrical cavity 32.

The excavation ability of the ultra-high pressure water 29 ejected from the nozzle 17 decreases as the distance increases in the horizontal direction from the discharge port 17b of the nozzle 17, so as the diameter of the cavity 32 being excavated increases as the excavation progresses. Therefore, the hydraulic jack 41e is driven to cause the rams 41f, 41f to retreat at a constant speed in the direction of arrow E in FIG. Then, through the links 41a, 41b, 41c, and 41d of the parallel movement mechanism 41, the nozzle 17 projects in the G direction, that is, in the direction of the wall surface 32a of the cavity 32 being excavated, while maintaining its discharge port 17b in the horizontal direction. , as shown in FIG. 3, protrudes and moves until the distance between the tip of the nozzle 17 and the axis of the excavation pipe 15 reaches L2. As a result, the distance X between the nozzle 17 and the cavity wall surface 32a, which is the surface to be excavated, is significantly shortened compared to the previous storage state of the nozzle 17, and the excavation ability of the ultra-high pressure water 29 from the nozzle 17 is greatly improved. This improves the ability to smoothly and reliably excavate and form a cavity 32 having a large diameter.

Note that, since the high-pressure liquid supply pipe 20 is formed to have flexibility, even if the nozzle 17 moves in the horizontal directions G and H, the high-pressure liquid supply pipe 2
0 and the nozzle 17 are maintained well. Furthermore, when cutting the cavity 32, the excavation pipe 15
rotates only within an angular range of 360°, so the connection state between the high pressure liquid supply pipe 20 installed in the excavation pipe 15 and the flexible tube 22 is
is maintained well without getting entangled with the excavation pipe 15,
The ultra-high pressure water 29 is supplied smoothly, and therefore the cavity 32 is formed without any hindrance. Note that the shape of the cavity 32 during excavation is such that ultrasonic waves 33 are transmitted from the ultrasonic ranging sensor 19 to the cavity wall surface 32a.
It is possible to accurately grasp the distance by emitting a wave, capturing the reflected wave, and measuring the distance from the ultrasonic ranging sensor 19 to the wall surface 32a.

In this way, by appropriately expanding and contracting the parallel movement mechanism 41 in a manner that matches the diameter of the cavity 32 being excavated, the nozzle 17 is moved in the G and H directions, and the work is carried out while maintaining a high level of excavation ability of the nozzle 17. I'm going.

Once a cavity 32 of a predetermined size has been formed in the ground 31, while rotating the excavation pipe 15 and pulling up the nozzle 17 from the bottom of the cavity 32 in the C direction, cement milk, etc. is poured from the flexible tube 22 into the nozzle 17. supplying ground improvement agents,
The soil improvement agent is injected into the cavity 32 from the nozzle 17 at high pressure to fill the cavity 32 with the soil improvement agent (note that the excavation pipe 15 is used as a tremie pipe, and the opening 1
A ground improvement agent such as concrete may be filled into the cavity 32 and the pilot hole 26 through the hole 5a. ). At this time, the improving agent can be efficiently and reliably filled into the cavity 32 by moving the nozzle 17 appropriately in the G and H directions and jetting out the improving agent.

In this way, when the excavation pipe 15 is pulled up in the direction C while filling the ground improvement agent into the cavity 32 and the pilot hole 26, the filled improvement agent solidifies and a strong artificial ground is constructed in the ground 31. That will happen.

Once one artificial ground has been constructed, the mobile heavy equipment 2 is moved, a new pilot hole 26 is excavated in a position adjacent to the constructed artificial ground, a cavity 32 is constructed, and a ground improvement agent is added. The artificial ground is expanded by filling the cavity 32 with the previously constructed cavity 32 (in which the soil improvement agent has already been filled and solidified) and making it horizontally continuous.

Note that the parallel movement mechanism 41 for the nozzle 17 may be any type of mechanism as long as the nozzle 17 can be moved horizontally while the discharge direction of excavation water such as ultra-high pressure water is always maintained in a constant direction. Mechanisms of configurations may also be used, for example, as shown in FIGS.
As shown in the figure, a parallel crank mechanism is used as the parallel movement mechanism 41, and the link 41d is driven by a hydraulic jack 41e to cause the nozzle 17 fixed to the tip of the link 41c to protrude from the distance L1 to L2. Of course it is also possible.

Furthermore, the guide means such as the leader 3 that supports and guides the excavation pipe holding and rotating device 6 is not necessarily the same as the moving heavy equipment 2.
Although it is not necessary that the movable heavy equipment 2 is provided with a guide means, it becomes possible to efficiently excavate a large number of pilot holes 26.

(g) Effects of the Invention As described above, according to the present invention, the nozzle 17 can be moved horizontally to the excavation pipe 15 via the parallel motion mechanism 41, and the discharge direction of the nozzle 17 is always constant. Therefore, by moving the nozzle 17 in the horizontal direction as appropriate depending on the diameter of the cavity 32 during excavation, it is possible to maintain a short distance Then, the large mouth cavity 32 is connected to the nozzle 1.
Excavation can be easily carried out without any increase in the discharge pressure of excavation water such as ultra-high pressure water from 7, and ancillary equipment such as a pump can be small, simplifying and downsizing the entire configuration of the ground modification device 1. I can do it. Furthermore, compared to the conventional method of excavating a large-diameter cavity by rotating a nozzle installed separately from a normal nozzle using a stirring blade, the nozzle can be freely moved horizontally regardless of the flatness of the cavity. Not only can a single nozzle be made to protrude into the air, but also a large-diameter cavity can be effectively excavated with a single nozzle, making it possible to demonstrate powerful excavation ability with a simple configuration.

Furthermore, since the discharge direction of the nozzle 17 is always maintained constant in the horizontal direction, the nozzle 17 shown in FIG.
Unlike the case where the ground modification device 1 is used, an inconvenient situation such as the bottom of the cavity 32 being excavated in a circular shape does not occur, and a highly reliable ground modification device 1 can be provided.

In addition, since the parallel movement mechanism 41 stirs the excavated earth and sand in the muddy water 27, the muddy water 27 and the excavated earth and sand can be easily sucked up and discharged from the excavation pipe 15.

[Brief explanation of the drawing]

Fig. 1 is a front view showing one embodiment of the ground modification device according to the present invention, Fig. 2 is an enlarged front view of the vicinity of the nozzle of the ground modification device shown in Fig. 1, and Fig. 3 is an enlarged front view of the nozzle shown in Fig. 2 extended. 4 is an enlarged front view showing another embodiment of the present invention, FIG. 5 is an enlarged front view of the nozzle shown in FIG. 4 when extended, and FIG. 6 is a conventional nozzle. FIG. 2 is a front view showing a proposed example. 1... Ground modification device, 15... Excavation pipe, 16...
... Bit, 17... Nozzle, 29... Drilling water (ultra high pressure water), 31... Ground, 41... Parallel movement mechanism.

Claims (1)

[Claims] 1 Ground modification that has a rotatable drilling pipe with a bit attached to the tip, a nozzle is provided at the tip of the drilling pipe, and high-pressure drilling water is spouted from the nozzle to excavate the ground around the pilot hole. A ground modification device, wherein the nozzle is installed in the excavation pipe so that the nozzle can be moved horizontally in a protruding manner through a parallel movement mechanism, and the discharge direction of the nozzle is always constant.