JPH0227488B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a multi-shaft auger type soft ground improvement device.

Conventional technology In the past, various methods have been proposed as ground improvement methods, such as chemical injection method, high-pressure injection method, displacement method, dewatering method, and mixing and stirring method.In particular, the mixing and stirring method is a quick, reliable, and low-cost method. It can be constructed and is currently attracting the most attention.

Problems to be Solved by the Invention Various types of soil improvement devices have been proposed for use in the mixing and agitation method.In particular, the multi-shaft auger system is advantageous in that it can speed up construction. There is a limit to the number of walls that can be installed, and no matter how many walls you increase, you will only be able to improve the shape of a long, narrow wall, which is inconvenient, and there was a desire to expand the construction area. The present invention has been made in view of these demands.

Means for Solving the Problems The present invention comprises a hollow guide rod and a plurality of guide rods provided at the lower end of the rod for forcibly disturbing the ground and filling the forcibly disturbed ground with a liquid agent supplied from the rod. A multi-axis auger is equipped with an axial auger, and is composed of a horizontal base plate and a plurality of auger parts installed vertically on the bottom surface of the base plate and arranged in parallel at intervals on a straight line. The rod is connected to the lower end of the rod on the upper surface so as to be able to slide as appropriate in the parallel direction of the auger parts, and the base plate has a cutting blade protruding outwardly and upwardly so as to surround the peripheral side thereof. Further, the guide rod is provided with a first drive device for appropriately rotating the guide rod, a multi-shaft auger is provided with a second drive device for appropriately sliding the auger, and a third drive device for individually rotating the auger parts. The present invention relates to a multi-shaft auger type soft ground improvement device characterized in that each drive device is provided.

Embodiment An embodiment of the present invention will be described below based on the accompanying drawings.

In the figure, 1 has a hollow guide rod, and there is a supply port 1 for liquid such as cement milk on the circumferential side of the upper end.
A is provided.

Reference numeral 2 denotes a multi-shaft auger provided at the lower end of the guide rod 1, which includes a base plate 2a and a plurality of auger parts 2b, 2b', for example, two auger parts, which are attached in parallel on the lower surface of the base plate 2a. The auger part 2 is attached to the lower end of the rod 1 on the base plate 2a.
b, 2b' are supported so as to be slidable as appropriate in the parallel direction. The auger parts 2b, 2b' are
Bits 3, 3' are provided at the lower end, and stirring blades 4..., 4'... are provided in multiple stages up and down on the circumferential side.
4' are vertically shifted by half a pitch, and are arranged in such a manner that they overlap to some extent in a plane, and by this arrangement, the disturbed part of the ground can be effectively distributed in the parallel direction of the auger parts 2b and 2b'. It can be made continuous. The auger parts 2b, 2b' are hollow, and the hollow parts 5, 5' can be moved at any sliding position.
It is configured to communicate with the hollow portion 6 of the rod 1 via a liquid passageway (not shown) in the base plate 2a. Reference numerals 7 and 7' designate liquid injection holes formed in the auger parts 2b and 2b'.

8 is a first rod for appropriately rotating the guide rod 1.
This is a drive device, and a motor is shown in the figure, and the rotation of the motor is transmitted to the rotating inner ring (not shown) of the clamp 11 through a chain 9 and a sprocket 10 that meshes with the chain 9 in the conventional manner. It's getting old. The outer ring 11a of the clamp 11 is attached to the ground plane 1, for example.
2 (see Figure 4). It is desirable that the rod 1 be formed into a rectangular shape for reliable clamping.

13 is a second drive device for sliding displacement operation provided on the upper surface of the base plate 2a of the multi-axis auger 2;
The figure shows a cylinder, the tip of the rod 13a of the cylinder is connected to the circumferential side of the guide rod 1, and when the rod 13a is in the withdrawn position (see Figure 1), the rod 1 is in the center of the multi-shaft auger 2. It is becoming located.

Reference numeral 14 denotes a third drive device for individually rotating the auger parts 2b and 2b', which is provided on the lower surface of the base plate 2a of the multi-shaft auger 2. A motor is shown in the figure, and the rotation of the motor is controlled by an appropriate transmission mechanism. Through the auger part 2
b and 2b' are transmitted separately.

Reference numeral 15 denotes a chainsaw belt for ground excavation that is wound around the peripheral side of the base plate 2a of the multi-axis auger 2, and the chainsaw belt 15 has a blade portion 15a that projects laterally and a blade that projects upwardly. The second drive device 13 is housed in the upwardly projecting blade portion 15b. chainsaw belt 1
A third drive device 14 is used as a drive source for the drive unit 5.

FIG. 4 schematically shows the implementation status of ground improvement using the apparatus of the present invention in the order of steps. In the first step (see the left diagram in FIG. 4), the third drive device 14 is operated in the state shown in FIG. 1 to individually rotate the auger parts 2b, 2b' and the chainsaw belt 15. The guide rod 1 is inserted to a predetermined depth by the rotary excavation guide.

Next, in the second step (see the middle diagram in Figure 4), the first drive device 8 rotates the guide rod 1 while continuing the above-mentioned individual rotations, and the entire multi-shaft auger 2 at the lower end of the guide rod 1 is rotated. Let it rotate. By doing this, each auger part 2b, 2b' of the multi-axis auger 2 performs orbital rotation in addition to individual rotation (rotation), and approximately 1/2 of the parallel length of the auger parts 2b, 2b' is The ground is stirred as the radius of rotation.

Next, in the third step (see the right diagram in FIG. 4), while continuing the rotation of the above-mentioned parts, the second drive device 13
and connect the multi-axis auger 2 to the auger parts 2b, 2.
As the slide displacement in the parallel direction of b' progresses, the rotation radius of the multi-axis auger 2 increases accordingly.
Finally, the ground is stirred with a radius of rotation approximately equal to the entire length of the parallel lengths of the auger parts 2b, 2b'.

In this third step, the auger section 2b,
By gradually pulling up the guide rod 1 while squirting and filling the agitated ground with a liquid agent, such as cement milk, from the ejection holes 7, 7' of 2b', a wide cylindrical ground improvement is achieved. When pulling up the guide rod 1, the chainsaw belt 1
5 continues its rotation and revolution, and the blade part 15
The ground is excavated at points a and 15b to enable the rod 1 and the multi-shaft auger 2 to be pulled up to the ground.

In the illustrated embodiment, the range of ground improvement in the third step is approximately 4 degrees of individual rotation in the first step.
This has reached double the amount of rotation, and compared to individual rotation, the range of ground improvement can be dramatically improved.

In addition, if during construction, an obstruction such as a buried object interferes with lifting the rod 1, the obstruction can be easily cleared by returning the construction state to that of the second process or even the first process. can.

Effects As described above, in the present invention, a wide cylindrical ground improvement area can be obtained at once by the individual rotation, overall rotation, and sliding displacement of the multi-axis auger, expanding the area of improved ground and improving the performance of the device. It has characteristics that can be significantly improved.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line A to A in FIG. 1,
FIG. 3 is a front view showing the situation when the multi-axis auger is slid and displaced, and FIG. 4 is a process diagram schematically showing the construction situation of the apparatus of the present invention. In the figure, 1 is a guide rod, 2 is a multi-shaft auger, 2a is its base, 2b, 2b' are its auger parts, 3, 3' are bits, 4, 4' are stirring blades, 5,
5' and 6 are hollow parts, 7 and 7' are nozzle holes, and 8 is the first
Drive device, 9 is a chain, 10 is a sprocket,
11 is a clamp, 12 is a ground machine, 13 is a second drive device, 14 is a third drive device, and 15 is a chainsaw belt.

Claims (1)

[Claims] 1 Equipped with a hollow guide rod and a multi-shaft auger that forcibly disturbs the ground and fills the forcibly disturbed ground with the liquid supplied from the rod. It is composed of a plurality of auger parts arranged in parallel at intervals on a straight line, and a rod is attached to the lower end of the rod on the upper surface of the base plate so that it can be slid as appropriate in the parallel direction of the auger parts. The base plate is provided with a digging blade that protrudes outwardly and upwardly so as to surround the circumferential side thereof, and further includes a first drive device on the guide rod for appropriately rotating the cutting blade. A multi-shaft auger type soft ground improvement device characterized in that the shaft auger is provided with a second drive device for appropriately sliding the auger, and a third drive device for individually rotating the auger parts. .