JPS62153412A - Improver for seabed soft ground - Google Patents

Abstract

PURPOSE:To adequately improve a necessary position of seabed soft ground by providing a rotary stirring blade in an improver for the seabed soft ground. CONSTITUTION:A pile 1 as a guider and reinforcing material to be driven into the seabed soft ground 4 and a stirrer 2 to be fitted into the pile 1 while being supported by a supporting frame 7 on a ship are provided. The stirrer 2 is provided with a rotary part 10 having a stirring blade 17 with a nozzle 16 through which cement milk is jetted and a rotation-stopping mechanism provided between the rotary part 10 and the pile 1 supporting the part 10, and comprises a body 3 hung down by a wire 25 from the supporting frame 7 in a rocking manner. Since only a necessary portion of the seabed soft ground 4 can be surely improved, the operating time can be shortened, and the cost can also be curtailed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement device for soft ground on the seabed.
This invention relates to an improvement device for forming soil cement around piles driven into weak ground.

[Conventional technology]

Conventional soft ground improvement is carried out as shown in Figure 3.

First, the work boat 8 is placed on a predetermined sea surface 15 in a sea area on soft ground to be improved. In addition, the work boat 8 has the anchor 20 held below the seabed surface 5 and the mooring wire 1
9 and lock it on the ti screen.

Next, while rotating the winch 9 on the work boat 8, the stirring motor 6', the stirring shaft 27 mounted below the motor, and the stirring blade 17 are lowered, and the stirring 1'1 is lowered.
The tip of the blade 17 is inserted into the soft ground 4 below the seabed surface 5.

That is, the stirring motor support groove 7 erected in the -ygJ section of the work boat 8 is provided with a motor lifting guide part 71), and the motor lifting guide part 7b is further provided with a motor lifting guide part 7b. A stirring motor 6' is mounted so as to be vertically movable via an idle roller 10'.

When the stirring motor 6' is lowered, one end is connected to the stirring motor 6' and the end of the pond is wound around the winch 9 on the ship while being guided by the fixed slide IIL 7a at the upper end of the stirring motor support frame 7. The rotated motor lifting wire 9a is sent out by reversing the winch 9. As a result, the stirring motor 6', the stirring shaft 7) 27. The stirring blade 17 is moved by its own weight to the motor lifting guide section 7.
b, and the tip of the stirring blade 17 enters into the soft ground 4.

Next, the stirring motor 6' is operated in normal rotation to rotate the stirring blade 17 via the stirring shaft 27.

Along with this rotation, the stirring blade 17 advances downward in the soft ground g14.

When the stirring blade 17 has advanced to a predetermined depth within the soft ground 4, the rotation of the stirring motor 6' is stopped.
Two.

Next, the onboard cement milk pump 12 is activated to drive the cement milk created in the onboard cement mixer 11, and the cement milk is pumped into the stirring blade 17 through the cement milk pumping pipe 13. The cement milk is ejected into the soft ground 4 from the cement milk ejection nozzle 16 provided at the tip of the stirring blade 17.

At the same time, the stirring motor 6' is rotated in reverse while the stirring blade 17 is gradually retreated to the upper blade in the soft ground 4.

Then, when the stirring blade 17 rises to the seabed surface 5, the operations of the cement milk pump 12 and the stirring motor 6' are stopped.

As a result, columnar soil cement 18a, which is a mixture of solidified cement and soil, is formed in the soft ground 4, and the ground is improved. Soil cement like this) 18a is a soft ground! 24, the required number is formed at each required location.

[Problem that the invention seeks to solve]

However, in the conventional soft ground improvement means as described above, in places where the water depth is large, the stirring shaft 27 also needs to be long.
must have a higher rigidity, that is, a certain diameter, in order to prevent it from swinging around during rotation.

Therefore, the weight of the stirring shaft 27 is quite large, and the stirring motor 6' that drives the stirring shaft 27 and the stirring blade 17 must also have a large capacity. 7) 27
．． The stirring motor support frame 7 that supports the stirring motor 6', the motor lifting/lowering guide section 7b, and the work boat 8 itself must also be made larger, which poses a major problem in terms of cost.

In addition, even if the rigidity of the stirring shaft 27 is increased, if it is not possible to prevent the stirring shaft 27 from whirling around when stirring the soft ground 4, the whirling will continue and the necessary minimum amount will be applied only to the required ground improvement locations. However, it is difficult to form soil cement 18α. Furthermore, when the work boat 8 is shaken by waves etc., the stirring shaft 27 is also shaken due to the shake of the ship, making it even more difficult to form soil cement +8a only on the required seabed ground. Put it away. This results in an increase in work time and work costs.

Furthermore, soil cement 18a, which is a mixture of solidified cement and soil, has compressive strength due to the characteristics of soil and concrete, but has extremely low tensile strength, so tensile force acts on the improved soft ground. Another problem is that the soil cement 18a has almost no reinforcing effect.

The present invention is an attempt to solve the above-mentioned problems, and while making each device lighter and easier to use, it also appropriately improves the necessary parts even at deep seabeds, and is capable of pulling tension onto the improved ground. It is an object of the present invention to provide a submarine soft ground improvement device that can improve the ground so that it can sufficiently withstand even when force is applied.

[Means for solving problems]

Therefore, the submarine soft ground improvement device of the present invention includes a pile that is driven into the seabed soft ground and serves as a reinforcing material, and a stirring rock that is supported by a support on a ship and fitted into the pile. a cement milk spouting nozzle provided on the stirring blade of the stirring rock; The main body is made up of a V
It is characterized by being suspended by wire from the support groove.

[For production]

In the above-mentioned VC system for improving seabed soft ground of the present invention, the stirring member rotates the stirring blade of the rotating part, and while being guided by the piles driven into the required seabed soft ground, the agitation member rotates the stirring blade of the rotating part, and while being guided by the piles driven into the required seabed soft ground, F.J.
After stirring the above-mentioned soft seabed ground without being affected by the J-shake, cement milk was spouted from the cement milk spouting nozzle while rotating the stirring blade, and the soil and cement milk were mixed around the pile. Strengthen soft ground by forming soil cement.

〔Example〕

Below, a submarine soft ground improvement device as an embodiment of the present invention will be explained with reference to the drawings. FIG. 1 is a schematic configuration diagram thereof, and FIG. 2 is a schematic sectional view of the ground improved thereby.

As shown in FIG. 1, on one edge of the work boat 8 at sea, there is a
A support frame l+''17 is erected, and the upper end of the support frame 7 is provided with a constant slide rlt7a.

Furthermore, a stirring-like lifting winch 9 is provided on the work boat 8, and a wire 9a for suspending the stirring mixture, one end of which is wound around the winch 9, is connected to the stirring member through a hanging wire 26 and a hanging wire 25. Hanging number 2. In other words, the stirring wire 9a is guided by the fixed pulley 7a, and the other end is connected to the hanging fitting 2G.
It is connected to the. One end of the hanging wire 25 is connected to each of the four corners of the hanging fitting 26, and the other end of each hanging wire 25 is connected to the upper end of the ring 4'1 and the rock 2.
6 Furthermore, in the areas of soft seabed soil fi4 to be improved, piles 1 are buried in advance using a pile-driving ship, etc., with their upper ends protruding above the seabed surface 5. has been done. A plurality of guide vanes 6 as anti-rotation members are fixed to the resistor 1 in its axial direction.

The stirring member 2 is composed of a main body 3 and a rotating part 10, and the rotating part 10 has four stirring blades 17 radially protruding from the lower end of each stirring blade 17. A jet nozzle 16 is formed.

A hole 2[1 as a rotation preventing member is formed in the center of the stirring pattern 2, and the stake 1 is inserted into the same size 2a. In other words, a hole 2a is formed in the main body 3 of stirring mode 2 from a hole corresponding to the pile 1 and a recess corresponding to each guide vane 6 around the hole, and the resistance 1 of the guide vane 6 attached is formed in this hole 2a. While fitting, a rotation prevention mechanism is formed and the main body 3 is prevented from rotating.

Further, the main body 3 of the stirring mode 2 is equipped with a stirring motor (not shown), and the rotating part 10 is turned into a rotating part by the motor! I! IJ is done. In addition, the stirring motor electric 1172
1 is provided on the work boat 8, and power is supplied via the work cable 23.

Furthermore, a flow path (not shown) is formed in the stirring mode 2 for supplying cement milk to each cement milk spouting nozzle 16, and this flow path is connected to the stirring mode 2 for pumping cement milk. It is in communication with the pipe 13.

Then, the cement mixer 11 installed on the work boat 8
The produced cement milk is driven by the cement milk pump 12 installed on the work boat 8, passes through the cement milk pump pipe 13, and is sent from the flow path in the stirring member 2 to the cement milk jetting nozzle 16. It is designed to be pumped to

Since the submarine soft ground improvement apparatus as an embodiment of the present invention is configured as described above, the soft ground improvement work is performed in the following manner.

A work boat 8 is placed on a predetermined sea surface 15 (above piles 1 buried in advance) in a sea area on soft ground to be improved. In addition, the work boat 8 has an anchor 20 held below the seabed surface 5 and is anchored on the sea surface via a mooring wire 19.

Then, the winch 9 on the work boat 8 is activated to send out the wire ○a. In this case, the stirring element 2 suspended from the wire 9a descends through the seawater 14 due to its gravity and reaches the upper end of the pile 1.

At this time, in order to ensure that the stirring mode 2 reaches the upper end of the pile 1 in the seawater 14, one end of the stirring wire 4't' R guiding wire is connected to the upper end of the pile 1 as shown in the figure. , Q/j) of the same wire are collected in the work boat 8 on the sea surface and guided by this stirring allowance guiding wire.
The stirring rock 2 is lowered.

Furthermore, the stirrer 2 is fitted onto the pile 1 while being guided by the rock guide wire. This results in
The lower end of the stirring blade 17 of the stirrer 2 penetrates into the soft seabed ground 4 due to its own weight.After this, the wire 9a
to prevent the vibrations of the vessel 8 from being transmitted to the stirrer 2.

And stirring 4'H! By operating a motor (not shown) in the main body 3 of 12 in normal rotation, the stirring blade 17 is rotationally driven and advances downward in the soft seabed fiA.

That is, the stirring blade 17 stirs the inside of the soft seabed ground 4 while descending along the pile 1 . At this time, the main body 3 of the stirrer 2 receives the reaction force of the rotating force of the rotary unit 10 equipped with the stirring blade 17,
The main body 3 is prevented from rotating due to this reaction force while being fitted with the guide vane 6 of the main body 3.

The stirrer 2 reaches a predetermined depth within the soft ground 4 of the seabed.

After penetrating, the stirring motor (not shown) inside the main body 3 is stopped. Next, the winch 9 is operated to pull up the agitator 2 while winding up the wire 9a, and the motor is operated in reverse. As a result, the stirring blade 17 gradually rises upward in the soft ground 4 while rotating. At the same time, the operation of the cement milk pump 12 is started, and the cement milk from the cement mixer 11 is pumped to the cement milk spouting nozzle 16.
Milk is squirted from the tip of the soft ground.

In this way, when the stirrer 2 rises to the seabed surface 5, the cement milk pump 12 and the stirring motor are stopped. Then, while winding up the wire 9a with the winch 9, the agitator 2 is further raised and recovered to a work boat on the sea.

As a result, in the soft ground 4, i [as shown in Figure 2,
A column-shaped soil cement 18a is formed around the pile 1, which is a mixture of solidified cement and soil.

The improved ground 18 provided with soil cement 18a is formed around each of the piles 1 at the required locations in the soft ground 4 in the required number.

As mentioned above, since the stirring motor that drives the stirring blade 17 is provided in the stirring 8!2, the vibration h of the stirring machine 2 is
l1li') fi' 1iJjstopzh, It 4↑
It has the advantage that the motor can be made small.

In addition, when stirring the soft ground on the seabed, (!) Since the rocky shore 2 is not restrained by the work boat 8, the shaking of the ship due to waves etc. is not transmitted to the stirrer, making stirring work extremely easy. 1li- of the support framework 7 etc. for the stirrer 2.
The strength and rigidity required by the four-body equipment are reduced, and there is also the advantage that these hull equipment can be made smaller and lighter.

Since the agitator 2 advances and retreats while being guided by the pile 1, soil cement 13a is reliably formed around the pile 1 and the soft ground is improved. In particular, in deep seabed areas, this ground improvement is reliably carried out at the required locations (locations where the piles 1 have been installed in advance), contributing to reductions in work time and work costs.

Furthermore, since the improved ground 18 is depleted from the pile 1 and the soil cement) 18g formed around it, the soil cement) 18a is mainly responsible for the vertical compressive force.
supports and reinforces the soft ground 4, and the piles 1 mainly support and reinforce the sea/bottom soft ground 4 against vertical tensile forces.

In this way, the undersea soft ground 4 is reliably reinforced and improved.

Also, Ii on pile 1! The attached guide vane 6 greatly expands the contact area between the pile 1 and the soil cement 18a, and has the advantage of strengthening the adhesion between the pile 1 and the soil cement 18a.

〔Effect of the invention〕

As described in detail above, according to the submarine soft ground improvement device of the present invention, there are piles that are driven into the seabed soft ground as guides and reinforcing materials, and piles that are supported by support structures on board the ship and are inserted into the piles. The above-mentioned stirring device 1 is equipped with a stirrer that can
゛The rock is composed of a rotating part having the above-mentioned stirring blade, and a main body that supports the rotating part and forms a rotation prevention mechanism between the above-mentioned resistance, and the main body is rocked against the support frame on the ship. Thanks to its elegant configuration, in which it is movably suspended by wires from the support frame, it is possible to miniaturize the various equipment involved in ground improvement, and it is also possible to reliably improve only the required points in the soft seabed ground. This has the advantage of shortening the work time for soil improvement and reducing the cost of each device and work.

In addition, the improved ground has piles in solid cement.
In particular, it has the effect of reinforcing the ground against tensile forces and extremely reliably strengthening and improving soft seabed ground.

[Brief explanation of drawings]

Figure f51.2 shows a submarine soft ground improvement device as an embodiment of the present invention, and Figure 1 is a schematic diagram of its configuration;
FIG. 2 is a schematic sectional view of the ground improved thereby, and FIG. 3 is a schematic configuration diagram showing a conventional submarine soft ground improvement device. 1. Pile, 2. Stirrer, 2a. Hole as anti-rotation member, 3. Stirrer fixing part, 4. Soft seabed ground, 5
... Seabed surface, 6. Id vane as a rotation prevention member, 7. Support Song groove, 7a. Fixed pulley, 8. Work boat, 9.
・Winch for lifting the rocky shore 4'1'', 9a... Wire for lifting the stirring rocky shore, 10... Rotating part of the stirrer, 11... Cement mixer, 12... Pump for pumping cement milk, 13
...Semen) Vibrator for pumping milk, 14...Seawater, 15
・・Sea level, 16・・For cement milk spout 77: Le, 1
7...P1も1゛blade, 18...Improved ground,
18a... Soil cement, 19... Mooring wire,
20φ・Anchor, 21・・Power supply, 23・・Moving cable, 25・・Hanging wire, 26・・Hanging fittings.

Claims (1)

[Claims] It is equipped with a pile that serves as a guide and reinforcing material that is driven into the soft ground of the seabed, an agitator that is supported by a support structure on a ship and fitted into the pile, and a nozzle for spouting cement milk that is installed on the stirring blade of the agitator. , the agitator is composed of a rotating part having the agitating blade, and a main body that supports the rotating part and forms a rotation prevention mechanism between the above-mentioned pile, and the main body is attached to the support frame on the ship. On the other hand, a submarine soft ground improvement device is characterized in that it is suspended by wires from the same support frame so as to be able to swing.