JPS639607Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a ground improvement device, particularly a ground improvement device useful when applied to improving soft ground.

The applicant first inserts a guide casing into the ground under the guidance of the tip bit, and when the insertion reaches a predetermined depth, inserts an arm with a chain cutter that can be freely stored and extended into the casing into the ground. As the cutter rotates, the casing extends into the ground from the stored state at the time of insertion, and then continues to rotate the cutter to disturb the ground and gradually pull the casing out of the ground.At the same time, the jet formed on the arm and tip bit We proposed a device that improves the ground by injecting a liquid (grout) into the disturbed ground through a hole (see, for example, Japanese Patent Publication No. 32531/1983). This ground improvement device can improve the ground stably and reliably over a certain width without being affected by the soil quality, and improves the soil quality better than conventional methods such as jet grouting, which inject liquid directly into the ground. It is excellent in that ground improvement can always be carried out stably and reliably over a certain width without being affected. However, this type of equipment has a narrow construction width equivalent to the width of a chain cutter, so when it is applied to ground improvement over a wide width such as soft ground or a wide area range, the construction width becomes too small. The narrowness inevitably caused problems in terms of work efficiency, making it unsuitable for such uses. Additionally, if the cutter was covered with sticky soil, there was a risk that the soil disturbance effect would be reduced.

The present invention has been made with the aim of eliminating such conventional problems, and one embodiment of the present invention will be described below with reference to the accompanying drawings.

In the figure, reference numeral 1 denotes a guide rod having a tip bit 2 at the lower end for guiding excavation into the ground, and at two places on the left and right on the circumferential side of the lower end of the guide rod 1.
A set of two arm cutters 3 and 3' are each provided with horizontally arranged central axes that are aligned vertically, and are rotated when inserted into the ground, and rotated and rotated when pulled up from the ground. There is. In the present invention, at least one set of such arm cutters 3, 3' is sufficient. Further, each set may include two or more arm cutters 3 (or 3').

Arm cutters 3, 3' and tip bit 2
In order to perform ground operation and rotate (including rotation and revolution), for example, the guide rod 1 has double inner and outer pipes 1a that are individually rotated by drive devices 4 and 5 installed on the ground (see Figures 5 and 6). , 1b, and the lower end of the inner tube 1a is connected to a horizontally arranged upper penetrating shaft 6a passing through the lower end of the outer tube 1b via a first rotation transmission mechanism 7 using an umbrella gear. The upper arm cutters 3, 3 integrally supported at both ends of the shaft 6a are given autorotation (rotation with the central axis of the arm cutter 3 as the rotation axis, the same applies hereinafter), and the upper penetrating shaft 6a is arranged in parallel directly below the upper arm cutters 3, 3. The lower arm cutters 3', 3', which are connected to the lower penetrating shaft 6b via a second rotation transmission mechanism 8 using a flat gear and are integrally supported at both ends of the lower penetrating shaft 6b, are given rotational rotation; The lower penetrating shaft 6b connects to the support shaft 2a of the tip bit 2 via a third rotation transmission mechanism 9 using a bevel gear.
is connected to give rotation to the tip bit 2. Further, since the arm cutters 3, 3' are supported by upper and lower penetrating shafts 6a, 6b that pass through the lower end of the outer tube 1b, when the outer tube 1b is rotated by the drive device 5, the arm cutters 3, 3' is revolved around the central axis of the outer tube 1b as the rotation axis. In the present invention, the rotation transmission mechanism is not limited to the one shown in the drawings, and other types may be used.

Cutter parts 3a, 3 of arm cutters 3, 3'
a' are arranged in a comb-teeth pattern, for example, as shown in Fig. 3, they are formed in four rows at 90° intervals, and are configured to mesh with each other at the same or different rotation speeds. There is.

In order to make the rotational speeds of the arm cutters 3 and 3' different, for example, as shown in FIG.
The flat gear wheels 8a and 8b on the upper and lower penetrating shafts 6a and 6b have different diameters. As shown in the figure, an intermediate pinion 8 is located between the pinion 8a and 8b.
c, the upper and lower penetrating shafts 6a and 6b, as well as the upper and lower arm cutters 3 and 3' connected to both ends thereof, can be rotated in the forward direction, and by doing so, the earth and sand that is a concern due to reverse rotation transmission can be rotated in the forward direction. It can prevent the tendency of biting.

The upper and lower arm cutters 3, 3' and the tip bit 2 have nozzles 10a, 10a' and 10b, respectively.
are formed, such as nozzles 10a, 10a' and 10b.
are liquid passages 11a, 1 formed in the upper and lower arm cutters 3, 3' and the support shaft 2a of the tip bit 2.
1a' and 11b, a liquid agent passage 11c formed in the lower part of the outer tube 1b so as to communicate with the liquid agent passages 11a, 11a' and 11b, and a liquid agent formed in the inner tube 1a so as to communicate with the liquid agent passage 11c. Passage 11
d, it is connected to a liquid agent pumping unit 12 (see FIG. 5) installed on the ground.

When carrying out ground improvement using the illustrated device of the present invention, for example, as shown in FIGS. 5 and 6, the inner pipe 1a and the outer pipe 1b of the guide rod 1 are
They are individually held by the drive devices 4 and 5 on the ground plane A. The drive devices 4 and 5 are elevating members that are moved up and down along the guide rail _a2 by the elevating device _a1 , respectively.
Provided on _A3 .

FIG. 5 shows the situation at the start of construction. In the state shown in FIG. 5, the rotary drive mechanism 4 is driven and the inner pipe 1a
When rotation is applied to the cutter, this rotation is transmitted to the upper and lower arm cutters 3 and 3' and the tip bit 2 via the first, second and third transmission mechanisms 7, 8 and 9,
These are rotated around the central axis (rotation).
In the state shown in FIG. 5, the drive device 5 is in a non-driving state, the outer tube 1b is not rotated, and therefore the upper and lower arm cutters 3, 3' only rotate on their own axis, and do not rotate around their orbit ( Rotation about the center axis of the outer tube 1b as the rotation axis is not performed.

When the elevating member _a3 is lowered along the guide rail _a2 via the elevating device _a1 in the state shown in FIG. Drill a hole vertically,
Guide rod 1 is inserted into the ground and guided.

As shown in Fig. 6, when the insertion into the ground reaches a predetermined depth, while continuing to rotate the inner pipe 1a,
When the idle drive device 5 is driven to give rotation to the outer tube 1b, the upper and lower arm cutters 3, 3' start to revolve while continuing to rotate on their own axis, and disturb the ground within the radius of revolution. Therefore, while continuing the rotation and revolution of the upper and lower arm cutters 3 and 3', the tip bit 2 and the nozzle 10 of the upper and lower arm cutters 3 and 3' are disposed within the disturbed ground within the radius of revolution.
While spouting the liquid (grout agent) for ground improvement from a, 10a' and 10b, guide rod 1
By gradually pulling upward, the ground within the orbital radius can be improved all at once. In addition, when pulling up the guide rod 1, if there is an obstacle buried in the ground that prevents the upper and lower arm cutters 3, 3' from rotating, the guide rod 1 must be pulled up until the guide rod 1 passes the obstacle. Alternatively, the rotation of the outer tube 1b may be stopped, the revolution of the upper and lower arm cutters 3, 3' may be stopped, and only the rotation may be continued.

As described above, according to the present invention, the guide rod 1 can be inserted into the ground to a predetermined depth by the drilling guidance based on the rotation of the tip bit 2 and the upper and lower arm cutters 3, 3', and after being inserted to the predetermined depth. By rotating and revolving the upper and lower arm cutters 3, 3', it is possible to achieve ground improvement over a wide area whose radius is the overhang width of the cutters 3, 3'. If such soil improvement sections a are continued in a series, a thick underground continuous wall can be formed, and as shown in Figure 8, if multiple rows are combined by shifting them by half a pitch, the ground can be improved over a wide area. The purpose of improvement can be achieved, and it is extremely useful especially when applied to applications where it is desired to form a thick underground continuous wall or improve the ground over a wide area, such as in soft ground.

Furthermore, in the device of the present invention, arm cutter 3,
3' are provided in multiple stages at the top and bottom, so the ground disturbance effect can be improved compared to a single stage configuration, and the multi-stage configuration can increase the pulling speed and improve work efficiency.

Furthermore, the arm cutters 3 and 3' of each stage have their central axes aligned vertically, and the cutter portion 3
The cutter portions 3a and 3a' are arranged in a comb-teeth pattern and are configured to mesh with each other at the same or different rotational speeds, so these cutter portions 3a and 3a' are During disturbance, they mutually exert a cleaning effect and prevent sticky soil from adhering to the cutter parts 3a and 3a', so that the cutter parts 3a and 3a' are not affected by the geology of the ground. , it has the advantage of efficiently achieving the purpose of drilling and ground disturbance.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a vertical sectional view of the main part, Fig. 2 is a plan view of Fig. 1, and Fig. 3 is a plan view of Fig. 1.
The figure is a front view showing the combination of the upper and lower arm cutters, Figure 4 is a front view showing the arrangement of the flat gear wheels,
FIG. 5 and FIG. 6 are explanatory diagrams showing one usage situation of the device of the present invention, and FIGS. 7 and 8 are explanatory diagrams showing a ground improvement situation. In the figure, 1 is the guide rod, 1a is the inner tube, and 1b
is the outer tube, 2 is the tip bit, 3, 3' are the upper and lower arm cutters, 3a, 3a' are the cutter parts, 4,
5 is a drive device, 6, 6' are through shafts, 7, 8 and 9
are first, second and third rotational transmission mechanisms, 10a,
10a' and 10b are nozzles, 11a, 11a', 11
c and 11d are liquid agent passages, and 12 is a liquid agent pressure feeding section.

Claims (1)

[Scope of utility model registration request] The guide rod has a tip bit at the lower end for guiding excavation into the ground. At least one point on the circumferential side of the lower end of the guide rod is operated on the ground so that it rotates on its axis when inserted into the ground, and rotates on its axis and revolves when it is pulled up from the ground. The arm cutters are provided with horizontally arranged arm cutters that are rotated in multiple stages and whose central axes coincide with each other vertically, and the cutter portions of each arm cutter are arranged in a comb-teeth pattern and are configured to mesh with each other, Furthermore, the tip bit and each arm cutter are each formed with a liquid passage with a spout which is connected to a liquid pumping unit installed on the ground through a liquid passage formed in the guide rod. Device.