JPS5832246B2 - Method of constructing stable hardened ground in soft soil layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for easily constructing a stable hardened ground necessary for civil engineering into a soft soil layer by mixing and stirring the soft soil in the soft paper ground with a hardening agent such as Beton cement.

Conventionally, in order to obtain stable ground necessary for civil engineering in ponds, lakes, rivers, ports, etc. where sludge, etc. has accumulated on the ground, the sludge above is removed from the supporting ground such as the ground, and sand or sand is removed. It was necessary to replace the mountain top, etc., which required advanced technology, difficult work, and many days, and also resulted in high costs.

Moreover, there was also the problem of new pollution such as secondary pollution on land due to the large amount of sludge being shipped.

In view of the current situation, the present invention aims to provide a new method that can extremely easily construct stable ground necessary for civil engineering, and its feature is that the lower limit position of the stirring blade follows the unevenness of the supporting ground. This work method allows for the construction of stable hardened ground based on this supporting ground.

An example of implementing the present invention will be described based on the apparatus shown in the accompanying drawings.

FIG. 1 schematically shows an example of construction, and shows A
is a front view, and B is a side view cut along the line X-X of A.

In this figure, reference numeral 1 indicates supporting ground such as the underground, and the − part of the soft soil layer 2 that exists in the upward direction from the supporting ground 1 is covered with Beton cement up to the respective height h where the upper part forms a plane. This is a schematic diagram of a hardened ground 3 obtained by continuously curing the middle width W of the supporting ground along the unevenness of the support ground using a hardening agent such as the following.

FIG. 2 shows a hardening work vessel that is preferably used for carrying out the above-mentioned hardening process.

A is a front view, B is a side view, C is a partially enlarged detailed view of the stirring blade unit in Figure B, and D is a cutaway detailed view of the tip of the stirring blade.

Reference numeral 5 indicates a float of the work boat, which in this case is configured as a catamaran, and the upper part is for receiving the curing agent sent from land, stirring and mixing it again, and feeding it to the stirring blade means 6 to be described later. Agitator and slurry pump 8 are installed.

In addition, 9 is these power generating devices, and Y is a winch for maneuvering the work boat.

The stirring blade means 6 is guided by frames S, S provided on the rear side and is movable up and down, and is equipped with a plurality of stirring blade units 10 that are arranged in parallel to move up and down independently, as shown in Figure C. ing.

The stirring blade unit 10 is constructed in such a manner that the base plate 12 can be moved up and down within a pair of frames 11 and 11' having a U-shaped groove A.

That is, the opening is guided in the U-shaped groove by a guide roller provided on the side surface of the base plate 12 (only one side is shown in the drawing), and the motor 13 is mounted on the front surface of the base plate 12. The rotating shaft 16 for lifting and lowering is rotated via the chain wheels 14 and 15.

The rotation shaft 16 is rotatably supported by bearings 17 and 17', and gears 18 and 18' are attached to both ends.
8 and 18' are engaged with racks 19 and 19' attached to the front surfaces of frames 11 and 11', respectively.

Reference numeral 20 denotes another motor provided on the front surface of the base plate 12, and this motor is for rotating the stirring shaft 22 which passes through the interior of the base plate 12 via chain wheels 21, 21'.

On the other hand, the stirring shaft has a hollow interior, and a stirring blade 23 having a hollow interior is attached to the lower tip to communicate with the hollow stirring shaft, as shown in Fig. D. A large number of slits 24 for ejecting the curing agent are bored around the slit 23 .

The curing agent is fed from the slurry pump 8 through a suitable hose (not shown) to the upper end of the stirring shaft protruding above the base plate 12, and passes through the inside of the stirring shaft to the stirring blade. It is ejected from the slit 24.

Although not shown, the sludge hardening agent may be supplied to the stirring section through a separately provided pipe or the like.

Note that 25 is an earth pressure detection device attached to the tip of the stirring blade.

The stirring blade unit 10 is configured as described above, and the motor 1
3 rotates the rotation shaft 16, the gears 18, 18' rotate on the racks 19, 19' to raise and lower the base plate 12 itself along the racks 11, 11', and the stirring shaft 22 The position of the stirring blade 23 attached to the tip within the soft stratum can be changed at any time.

Therefore, while detecting the earth pressure with the earth pressure detection device 25, this lifting and lowering is carried out by motors that move part of the soft soil layer upward from the supporting ground up to the respective heights where the upper part forms a plane. This is done by changing the drive of 13.

In this example, a detection means in which an earth pressure detection device is provided at the tip of the stirring blade has been described, but the present invention is not limited to this example, and various other detection means can be employed.

For example, this can be done by detecting changes in the torque applied to the drive system, which similarly changes as the resistance changes when the stirring shaft moves downward.

As mentioned above, the stirring blade means 6 of the present device is for raising and lowering the stirring blades for each unit, and for example, each of the stirring blades a, b, c, d, etc. of each unit. When the motor 2 reaches any uneven surface of the supporting ground 1, it is detected and this detection command automatically turns the motor 2 on.
0 is driven to rotate the stirring blades, and at the same time, the hardening agent is ejected to perform hardening treatment within the stratum.

At this time, the driving of the motor 13 is changed to reverse rotation, and the stirring blades are raised one by one, and when the upper parts reach respective heights forming a plane, the driving of the motor 13 is changed to reverse rotation again, and the stirring blades are sequentially lowered.

By repeating this operation as the workboat progresses,
A part of the soft soil layer 2 existing in the upward direction from the supporting ground 1 is continuously hardened over a certain width and a certain length up to the respective heights where the upper part forms a plane.

The lower limit of the base plate 12 in each unit that moves up and down in this S varies depending on the unevenness of the supporting ground 1, but the upper limit determines the upper surface of the hardened ground, so it should be kept as constant as possible. is preferred.

For this purpose, as in the case described above, the motor 13 is
This can be done by changing the direction of rotation, but in this case, a simple method is to move the base plate 12 up and down by
It is recommended that a limit switch be installed at a certain position within the area so that when the plywood rises, it comes in contact with the limit switch.

If the limit switch is set to the same position for each unit, all the upper surfaces of the hardened ground will be formed on the same plane, but if necessary, arbitrary height differences can be formed inward and outward. A hardened ground can also be easily formed by simply changing its position as appropriate.

Therefore, necessary structures and buildings are installed directly or indirectly on the hardened ground.

The above explanation was an example in which the stirring blade means, which has a large number of stirring blades arranged in one stage in parallel, is operated as the work boat moves.
It is also possible to move the work boat intermittently, operate each stirring blade unit of the stirring blade means while the work ship is stopped, and repeat this operation.

Alternatively, if a stirring blade unit is constructed in which the stirring blades are moved up and down while rotating and moved horizontally when the work boat is stopped, it will have substantially the same effect as having a large number of stirring blades. Even with one stirring blade, the same hardening treatment as described above can be performed.

In either embodiment, the lower limit of operation of the stirring blades is determined by a command from the ground detection means that detects the uneven state of the supporting ground, so whether the stirring blades are operated manually or automatically. This allows work to be carried out while accurately following the unevenness of the supporting ground.

Although a detailed explanation has been omitted, the stirring blade means 6 has a frame body s as a whole.
, s' as a guide and can be further raised and lowered by a certain distance by the operation of the winch R, so that the above-mentioned hardening process can be carried out to a deeper layer.

In the above embodiment, the work boat is configured as a catamaran, and the frames s and s' supporting the stirring blade means 6 are provided at the stern of the ship. It may be located at the center, or it may be a four-hulled ship if the frame bodies s and s' are moved in the width direction of the ship.

Further, the work boat may be constructed so that it can be divided and combined as appropriate in consideration of transportation, assembly, etc.

Note that the stirring unit 10 may be configured such that the base plate 12 is movable up and down using a hoisting device, for example, a winch.

In this case, gears 18, 18' and rack 19°19'
Such mechanisms are not necessary.

3 to 5 illustrate working examples according to the present invention.

This will be explained below. Figure 3 shows the state in which a waterway is constructed in soft ground. First, as shown in Figure A, the middle width of the soft soil layer 2 on the supporting ground 1 is completely covered without leaving any untreated parts. Continuously hardened ground 3
Nasu.

Next, the hardened portion 240 is cut and removed and piled up on both sides of the hardened ground 30 to form a water channel wall.

Figure 4 shows the construction of stable hardened ground required for civil engineering in the sea, in which a soft soil layer 2 is extended upward from the supporting ground 1 to a width W7. W2. W3...
A hardened wall 3W1, 3W2, which is continuous in the length direction by being subjected to a partial hardening process.
A plurality of such walls (three in the drawing) are arranged in parallel at appropriate intervals within the soft soil layer, and the soft soil layer on each wall surface is completely or partially covered. The hardened ground 3 is hardened continuously at a constant height H2 to form a stable hardened ground 3.

The structure is formed by setting the stirring blades aybyc... to stop at the same upper limit position, and stirring blades a and c.

02g, . . . indicate the range of H2 and the stirring blade.

d, ft... are the stirring blades a, C by continuously curing the range (H2+H,).

A tunnel-shaped untreated portion remains under the H2 in e2gt... and is easily obtained.

On the upper surface thus obtained, necessary structures are constructed as appropriate based on the ground.

The drawing shows an embankment, where p indicates the foundation rubble,
q indicates root protection rubble.

Fig. 5 shows a case where the hardened ground 3 is structured in the shape of a grid, and the hardened ground 3 is covered with nets, ropes, sheet mats, etc. to form a foundation such as foundation rubble. Build embankments, roads, runways, etc. in the same way as above.

To form the structure, stirrer blades ayb, c, . . . are set to stop at the upper limit position, and stirrer blades C2f,
. . . are subjected to continuous curing treatment over time, and stirring blades a, btd, e, . . . are subjected to continuous curing treatment intermittently over time, stirring blade a,
It can be easily obtained by leaving square-shaped untreated portions in the portions b, d, e, . . . .

The soft ground improvement device used in the above-mentioned embodiments has a stirring blade means 6.
Although the explanation has been given on the case where one stage is provided in parallel, two or more stages may be provided in series, or they may be arranged in a staggered manner to achieve an effective hardening treatment.

Further, it is also free to configure it in a grid-like or other appropriate shape.

What is important in all of the embodiments described above is that the hardening treatment is performed in a state extending upward from the bottom along the unevenness of the supporting ground, and that the strength between the stirring hardened parts is the same. The bonded continuous layer is then cured.

In the present invention, the distance between the stirring ranges of the stirring blades is set so that the soft soil and the hardening agent are mixed, and the hardening process is performed.The stirring blades can also stir from the bottom upward along the unevenness of the supporting ground. In order to harden the hardening process, the subsequent curing process is performed while the previous curing process is in an uncured state. We solved this problem by operating the device so that it can be cured into a continuous hardening layer by injecting it into the preceding hardening process so that a portion of it polymerizes, and repeating the same operation. This is fundamentally different from the conventional continuous wall, in which hardened piles are arranged as close together as possible in parallel.

As described above, in the construction according to the present invention, the soft soil layer from the bottom to the top along the unevenness of the supporting ground is continuously hardened into the desired shape up to the husband's height and the middle width. , In this case, the respective treatment heights and dimensions of ↑W are determined appropriately depending on the size of the required stable hardening treated ground and the required strength, but at least in order to make the stable hardened treated ground necessary for civil engineering. should be designed so that the N value indicates a numerical value of 10 or more.

Such hardened ground is excellent in that it can prevent uneven settlement due to upper loads and does not cause settlement due to loading.

[Brief explanation of the drawing]

Fig. 1 schematically shows an embodiment of the construction according to the present invention, in which A is a front view, B is a side view cut along the line X- of A, and Fig. 2 is a hardening treatment work boat. A is the front view, B
is a side view, C is a partially enlarged detailed view of the stirring blade unit in Figure B, D is a detailed cutaway view of the tip of the stirring blade, and 3rd
5 to 5 are schematic explanatory diagrams showing examples of work. 1...Supporting ground, 2...Soft soil layer, 3
... Hardening treatment ground, 4 ... Hardening treatment work boat, 6 ... Stirring blade means, 10 ... Stirring blade unit, 11 ... - Frame, 12...
- Base plate, S... Frame body, 25... Earth pressure detection device.

Claims (1)

[Claims] 1. In the work of stirring and mixing soft soil and hardening agent in soft ground with stirring blades and hardening them upward from the supporting ground, the lower limit position of the stirring blade detects the unevenness of the supporting ground. A method for constructing stable hardened ground in a soft soil layer, characterized in that the work is determined by a command from a means and the work is carried out while following the unevenness.