JP6393003B1 - Press-fitting device and press-fitting method to submerged ground - Google Patents

Abstract

A method for press-fitting a casing into a seabed without relying on a counterweight is provided.
In a casing press-fitting method to seabed ground, a pressure control device in a casing 32 is used. The pressure control device includes a pump that sends compressed air into the underwater casing 32, an underwater exhaust pipe 56 that guides the air pressure in the casing 32 to the outside, and an elevating unit that raises and lowers the exhaust pipe. When the casing 32 is press-fitted into the seabed ground, the inside of the casing 32 is completely drained by pressurizing the inside of the casing 32 with compressed air, and the lower end of the casing is abutted against the seabed. Subsequently, the exhaust pipe 56 is pulled up with the bottom end of the completely drained casing 32 being in close contact with the seabed. Thereby, the water pressure acting in the casing press-fitting direction becomes dominant, and the casing 32 can be press-fitted into the seabed ground using this water pressure.
[Selection] Figure 13

Description

  The present invention relates to a press-fitting device, a press-fitting method, a material discharge device, a material discharge method, and a sediment take-in method that can be used in various constructions such as improvement of the bottom of the seabed, lake bottom, river bottom, etc. Specifically, the present invention relates to an apparatus and a method for press-fitting a casing into a submarine ground such as a seabed ground, a method for discharging material in the casing in water, and a method for taking soil and sand from the submarine ground into the casing.

  Conventionally, various constructions have been carried out for the purpose of improving the submarine ground and the seabed environment. Patent Document 1 discloses a technique that can be used for improving the seabed ground and the seabed environment. ing. FIG. 15 shows the steps of “seabed ground excavation”, “movement of excavated earth and sand”, and “discharge of excavated earth and sand” disclosed in Patent Document 1.

As shown in FIG.
(a) While pressing the casing into the seabed ground, excavating the seabed ground with a hydraulically driven bucket,
(b) Take the excavated earth and sand into the casing and move it to another place in the sea.
(c) The excavated earth and sand taken in the casing is discharged from the casing toward the seabed ground at an arbitrary location and timing.
Such a process is disclosed.

Japanese Patent No. 6209698 (FIG. 11)

  The techniques disclosed in Patent Document 1 have been proposed by the applicant of the present application, and it has been studied to use these techniques for various constructions for the bottom of the sea such as the seabed, lake bottom, and riverbed. Specifically, the apparatus and method disclosed in Patent Document 1 are used in construction involving press-fitting of a casing into the submarine ground, taking in earth and sand of the submarine ground into the casing, and discharging the material in the casing in water. Use is under consideration.

  However, the conventional techniques including Patent Document 1 have the following problems.

(Problems related to press-fitting of casing and earth and sand intake into casing)
In order to take the sediment at the bottom of the water into the casing, it is necessary to press-fit the casing into the bottom of the ground as shown in FIG. 15 (a). In the prior art, in order to obtain the pressure input of the casing, a counterweight (weight) is used. It was necessary to use the indentation load due to.
However, when the casing is press-fit by relying on a heavy-weight counterweight, there are problems that the construction equipment becomes large, the manufacturing cost of the construction equipment becomes high, and the assembly becomes complicated.

(Problems related to material discharge in the casing)
When the material in the casing is discharged in water, in the case of the prior art, the material is discharged in a natural fall while leaving the weight to its own weight.
However, when the material in the casing is viscous, it takes time to discharge the material, so that the construction takes time and it is difficult to proceed with the construction as scheduled.
Further, when the viscous material is discharged as described above, there is no choice but to wait for the material to be discharged due to natural fall in a situation where it cannot be predicted when the material in the casing will fall. Therefore, it was difficult to predict the time required for material discharge, and there was a problem that construction could not proceed as scheduled.

Then, in view of the subject mentioned above, an object of the present invention is to provide a press-fitting method and a press-fitting device that make it possible to press-fit a casing into a water bottom ground without relying on a counterweight.
Another object of the present invention is to provide a method for taking in earth and sand that makes it possible to take in earth and sand from the bottom of the ground into the casing without relying on a counterweight.
Another object of the present invention is to provide a material discharge method that enables a material in a casing to be discharged quickly and reliably in water.

The above object is a device for press-fitting a casing into a submerged ground,
A pump for sending compressed air into the underwater casing;
An exhaust passage for guiding the air pressure in the underwater casing to the outside of the casing;
Elevating means for raising and lowering the exhaust port of the exhaust path,
Depending on the relative height of the exhaust port with respect to the underwater casing, the air pressure in the casing varies,
It is achieved by a press-fitting device to the bottom ground, wherein the pressure in the casing underwater is lowered by raising the exhaust port of the exhaust passage in water, and the casing is pressed into the bottom ground by water pressure. .

The above purpose is
A pump for sending compressed air into the underwater casing, an exhaust passage provided to guide the air pressure in the underwater casing to the outside, and an elevating means for raising and lowering the exhaust port of the exhaust passage; A method of press-fitting a casing into a water bottom ground using a pressure control device in the casing comprising:
A step of bringing the lower end of the casing into contact with the bottom of the water in a state in which the inflow of water into the casing is prevented by pressurizing the inside of the casing with compressed air;
A step of raising the exhaust port of the exhaust passage in a state where the inflow of water into the casing is prevented by compressed air and the lower end of the casing is in contact with the water bottom;
This is achieved by a method of press-fitting the casing into the submerged ground.

The above purpose is
A pump for sending compressed air into the underwater casing, an exhaust passage provided to guide the air pressure in the underwater casing to the outside, and an elevating means for raising and lowering the exhaust port of the exhaust passage; Using a pressure control device in a casing comprising the following:
A step of bringing the lower end of the casing into contact with the bottom of the water in a state in which the inflow of water into the casing is prevented by pressurizing the inside of the casing with compressed air;
A step of raising the exhaust port of the exhaust passage in a state where the inflow of water into the casing is prevented by compressed air and the lower end of the casing is in contact with the water bottom;
It is achieved by the soil uptake method of submarine ground including.

The above purpose is
A method of discharging the material in the casing in water using a pump for sending compressed air into the casing in water, and a material pushing means provided so as to be able to be raised and lowered in the casing,
Positioning the casing containing the material at a material discharge position in water;
A step of pressing the material in the casing in the discharge direction by the compressed air in the casing and the material extruding means in a state in which the inflow of water into the casing is prevented by the compressed air;
This is achieved by a method for discharging material in water containing water.

  The casing used in the material discharging method has a bucket capable of opening and closing the lower end opening of the casing. And you may make it crush the material discharged | emitted by the casing in the state which the bucket closed.

  The apparatus and method according to the present invention can achieve excellent effects when applied to water engineering works such as improvement of water bottom ground and water bottom environment.

  In addition, as a specific example of the “water bottom” in the present invention, for example, a sea bottom, a river bottom, and a lake bottom are exemplified. Further, specific examples of the “water bottom ground” include, for example, a sea bottom ground, a river bottom ground, and a lake bottom ground. Specific examples of “water” include seawater, river water, and lake water.

  Hereinafter, the seabed is given as an example of the water bottom, and the seabed ground is given as an example of the water bottom ground.

The press-fitting device according to the present invention is a device for press-fitting a casing into the seabed ground,
A pump for sending compressed air into the underwater casing;
An exhaust path for guiding the air pressure in the underwater casing to the outside of the casing;
-Elevating means for raising and lowering the exhaust port of the exhaust path is provided.
According to such a configuration, the atmospheric pressure (compressed air pressure) in the casing varies in accordance with the relative height of the exhaust port by moving the exhaust port up and down relative to the casing in water. The water pressure acting on the casing varies.
Therefore, by pulling up the exhaust port relative to the underwater casing, the compressed air in the casing escapes to the outside. As a result, the atmospheric pressure is reduced and negative pressure is generated in the underwater casing. As a result, the water pressure acting on the casing becomes dominant, and the casing is pressed into the seabed ground by the water pressure. That is, by raising and lowering the exhaust passage in water, it is possible to freely control the pressure input due to the water pressure acting on the casing, and it is possible to reliably press the casing into the seabed ground using this water pressure. it can.
Therefore, according to the present invention, the casing can be easily and surely press-fitted into the target seabed ground regardless of the soil quality of the seabed ground.

In the press-fitting method according to the present invention, first, a state in which the inflow of seawater into the casing is prevented by pressurizing the inside of the casing with compressed air. In this state, the lower end (lower end opening) of the casing is brought into contact with the seabed. Subsequently, the exhaust port of the exhaust passage is raised (from this state) in a state in which seawater inflow into the casing is prevented by the compressed air and the lower end of the casing is in contact with the seabed.
According to such a method, by raising the relative height of the exhaust port with respect to the underwater casing at a predetermined timing, the water pressure acting on the casing (water pressure acting in the casing press-fitting direction) becomes dominant, and this water pressure is reduced. It becomes possible to press-fit the casing into the seabed ground. Therefore, according to the present invention, it is possible to easily and surely press the casing into the target submarine ground regardless of the soil quality of the submarine ground (for example, even viscous soil that is difficult to press with the counterweight alone). Become.
Further, in the present invention, since the casing is press-fitted using water pressure, a counterweight (a heavy load weight for press-fitting the casing) that is indispensable in the prior art becomes unnecessary. Therefore, construction equipment can be manufactured at low cost, and assembly of construction equipment can be simplified.

  Further, according to the earth and sand taking-in method according to the present invention, the relative height of the exhaust passage with respect to the underwater casing is increased at a predetermined timing, whereby the compressed air in the casing is discharged to the outside, and the atmospheric pressure in the casing is increased. Since it falls, the negative pressure resulting from this can be generated in the casing. Furthermore, it becomes possible to take in the sediment of the seabed ground (as if it is sucked) into the casing by using this negative pressure. Therefore, according to the present invention, it is possible to generate a negative pressure in the casing and easily and reliably take in the earth and sand of the target seabed ground into the casing.

Moreover, in the material discharge | emission method which concerns on this invention, it becomes possible to extrude the material in a casing reliably by the double extrusion action by the material extrusion means provided in the casing so that raising / lowering is possible and the compressed air in a casing. . That is, even when a material discharged in water has a viscosity, for example, the material can be forcibly discharged to the outside by a double pushing action against the adhesive force against the inner wall of the casing. It becomes.
Further, by forcibly discharging the material in this way, the material in the casing can be quickly discharged. As a result, it is possible to assume the time required to discharge the material once (compared to the case where the material in the casing is left under its own weight and waits for the natural fall as before), and the assembly of the construction schedule is possible. It becomes easy and construction can proceed according to the schedule.
Moreover, in the material discharge | emission method which concerns on this invention, the material in a casing is discharged | emitted in water in the state which prevented the seawater inflow into the casing with compressed air. Thereby, it can prevent that seawater mixes with the material in a casing, As a result, the quality fall and quality change of material by seawater mixing can be prevented. That is, it is possible to prevent the material from being deteriorated or altered when the material is discharged from the casing.
In addition, by preventing the inflow of seawater into the casing at the time of material discharge, it is possible to prevent water pollution (because there is no situation where the material is washed by the inflowing seawater), and consider the environment such as fishing grounds. It is possible to perform the construction.
Further, for example, when a series of cycles of “casing press-fitting → material discharge in the casing” is repeated, the cycle can be efficiently repeated without the trouble of drainage in the casing. Therefore, construction requiring these processes can be efficiently advanced.
Moreover, since the seawater in a casing is not drained at a time when starting the next cycle, the water pollution resulting from such drainage does not generate | occur | produce. Therefore, it becomes possible to perform construction in consideration of the environment.

  Moreover, in the material discharge | emission method which concerns on this invention, in the state which closed the bucket of the casing lower end, the material discharged | emitted by the casing is crushed by this casing. This makes it possible to adjust the top height of the material discharged to the seabed, for example, in construction such as shallow field construction.

Moreover, in the material discharge | emission method which concerns on this invention, the material discharged | emitted by the seabed ground is crushed with a casing in the state which prevented the inflow of the seawater into the casing with compressed air.
For example, when repeating a series of cycles of “press fitting of casing → material discharge in casing → crushing discharged material”, the cycle can be efficiently repeated without the trouble of drainage in the casing. Therefore, construction requiring these processes can be efficiently advanced.
Moreover, since the seawater in a casing is not drained at a time when starting the next cycle, the water pollution resulting from such drainage does not generate | occur | produce. Therefore, it becomes possible to perform construction in consideration of the environment.

It is the side view and front view which show an example of the work ship (ground improvement ship) which can be utilized for implementation of this invention. It is a top view which shows an example of the work ship (ground improvement ship) which can be utilized for implementation of this invention. 3 (a) is an enlarged side view showing the bow side of the work boat shown in FIG. 1 (a), and FIG. 3 (b) is a side view showing a single unit of the excavating and stirring and mixing apparatus shown in FIG. 3 (a). FIG. 3 (c) is a side view showing a single unit of the backfilling material input device shown in FIG. 3 (a). FIG. 4 (a) is an enlarged front view mainly showing the excavating and stirring mixing device provided in the work boat shown in FIG. 1 (b) (illustration of members adjacent to the excavating and stirring mixing device is omitted as appropriate) FIG. 4 (b) is a front view showing a single unit of the excavating and stirring and mixing apparatus shown in FIG. 4 (a). FIG. 5A is an enlarged front view mainly showing the backfilling material charging device provided in the work boat shown in FIG. 1B (illustration of members adjacent to the backfilling material charging device is omitted as appropriate). FIG.5 (b) is a front view which shows the single body of the backfilling material injection | throwing-in apparatus shown to Fig.5 (a). FIG. 6B is an enlarged side view showing a specific configuration of the excavation and stirring and mixing device included in the work boat shown in FIG. 1B, and FIG. 6A shows a state in which the bucket (excavation means) at the tip of the casing is opened. Fig. 6 (b) shows the operation of the bucket when excavating the seabed ground, and Fig. 6 (c) shows the state where the bucket is open and the excavating and agitating mixing blades are lowered to lower the seabed ground. FIG. 6 (d) shows a state when the excavated earth and sand is taken into the casing and the bucket is closed. FIG. 7 is an enlarged front view showing a specific configuration of the excavating and stirring mixing device provided in the work boat shown in FIG. 1 (b), and FIG. 7 (a) shows a state in which the excavating and stirring mixing blade in the casing is raised. FIG. 7B shows a state where the excavating and stirring blades in the casing are lowered. It is a side surface enlarged view which shows the excavation and stirring mixing part shown in FIG.6 (b). It is a schematic block diagram, a side view, and a front view showing a casing internal pressure control device. It is a figure which shows the function effect | action of the pressure control apparatus in a casing. It is process drawing which shows the main processes of the water construction using this invention. It is process drawing which shows the main processes of the water construction using this invention. It is process drawing which shows an example of the casing press-fit method to the water bottom ground which concerns on this invention. It is process drawing which shows an example of the casing press-fit method to the water bottom ground which concerns on this invention. It is process drawing which shows an example of the earth and sand taking-in method of the water bottom ground which concerns on this invention. It is the side view and front view which illustrate the process of a prior art.

(Work ship)
First, based on FIGS. 1-8, the structure of the work ship (ground improvement ship) utilized as an example by this embodiment is demonstrated. Note that the work boat illustrated in this embodiment is an example of work equipment that can be used in the implementation of the present invention, and the present invention is implemented using heavy equipment prepared on land instead of such a hull. It is also possible.

The work boat 1 used in the present embodiment has an appearance as shown in FIG. 1 and FIG.
Moreover, as shown in the detailed views of FIGS.
・ Work ship positioning system using anchor wire 2 (see Fig. 2),
A leader 3 standing on the bow side of the work boat 1,
An excavating and stirring and mixing device 5 provided so as to be movable up and down along the leader 3;
A backfilling material input device 7 provided so as to be movable up and down along the reader 3;
A guide rail provided on the side of the reader 3;
A lifting and lowering bucket 9 for material charging provided so as to be movable up and down along the guide rail;
A weighing hopper 11 for weighing improvement materials and filling the lifting bucket 9;
A sand box 13 (material storage box) for storing improvement materials and backfill materials used for construction;
It has a belt conveyor 15 that conveys the improvement / backfill material in the sand box toward the weighing hopper 11.

  Specific examples of the “improving material” include a modifying material, a purifying material, an insolubilizing material, and the like. In the present embodiment, the term “improving material” is used as a general term for a modifying material, a purification material, an insolubilizing material, and the like. The backfill material and the improvement material may be composed of the same material.

  In addition to the above-described configuration, the work boat 1 has a “casing pressure control device” that is a device for controlling the pressure in the casing included in the excavation and stirring and mixing device 5. Details of the casing internal pressure control device will be described later. This casing pressure control device functions as a “press fitting device” when the casing is pressed into the seabed ground as shown in FIG. 12, and when the material in the casing is discharged in water as shown in FIG. Functions as a “material discharger”.

  Hereinafter, the configuration of the main part of the work boat will be described in detail.

(Work ship positioning system)
The work ship positioning system is a combination of a position guidance screen using GPS, a winch fixed to the work ship 1 and an anchor wire 2 connected to the winch so as to be able to wind and unwind as shown in FIG. It is configured to include multiple sets. The winch to which the anchor wire 2 is connected is provided, for example, near the four corners of the work boat.

  By selectively operating one or more of the plurality of anchor wires 2, the work ship 1 can be moved in any direction on the sea surface as shown in FIG. It can be positioned at a desired location in the field.

(Drilling and stirring mixing device)
The excavation and stirring and mixing device 5 is a device that mainly has a function as an “excavating device” for excavating the seabed ground at a predetermined position and a function as an “agitation and mixing device” for stirring and mixing the excavated soil and the improved material. is there.

The excavating and stirring and mixing device 5 is provided so as to be movable up and down along the leader 3.
As shown in FIG. 3, FIG. 4, FIG. 6, FIG.
A pair of material supply pipes 21 that are feed paths for guiding the improved material into the casing 32;
A material inlet 23 for introducing an improved material into the material supply pipe 21;
An auger motor 25 which is a rotary drive device;
A drilling and stirring and mixing unit 29 provided at the lower ends of the material supply pipe 21 and the rod 27;
A rod 27 for transmitting the power of the auger motor 25 to the excavating and stirring mixing blade 35 in the excavating and stirring and mixing unit 29;
have.

  As shown in the front view of FIG. 7, two sets of the material supply pipe 21 and the material input port 23 are provided for one excavating and stirring and mixing apparatus, and the rod 27 is positioned between the material supply pipes 21 and 21. As shown, a pair of material supply pipes 21 and 21 are provided at an interval. The upper end side of each material supply pipe 21 communicates with the material input port 23, and the lower end side communicates with the inside of the casing 32 of the excavating and stirring and mixing unit 29.

  The material supply pipe 21 also serves as an air flow path (pressure pipe) for sending compressed air into the casing 32. By sending compressed air from the air pump into the casing 32 through the material supply pipe 21, seawater can be discharged from the casing 32 in a state of being submerged in the sea by the air pressure. It is possible to maintain a state in which seawater is discharged from the inside of the air.

  The rotational power output from the auger motor 25 is excavated in a casing 32 of the excavating and stirring and mixing unit 29 via a rod 27 located between the pair of material supply pipes 21 and 21 (see FIG. 7). It is transmitted to the cum stirring and mixing blade 35.

  The auger motor 25 is connected to the reader 3 so as to be movable up and down as shown in FIG. 3 (a), and its upper end is connected to a wire rope 26. By operating the wire rope 26 in the vertical direction, the entire excavating and stirring and mixing apparatus 5 including the auger motor 25 moves up and down along the leader 3.

The excavation and stirring and mixing unit 29 provided at the lower end of the material supply pipe 21 is
As shown in FIG. 6, FIG. 7, FIG.
A sealable casing 32 with an openable bucket 31 (excavation means);
An excavating and stirring mixing blade 35 provided so as to be movable up and down in the casing 32;
have.

  The casing 32 is a box-shaped container-shaped component (rectangular casing) having a substantially rectangular shape in plan view, and is configured to be able to open and close the opening at the bottom. The top end of the casing 32 is closed so that seawater does not enter the casing from above. Moreover, the upper surface side of the top end of the casing 32 functions as a water pressure receiving surface that receives water pressure from seawater located above the casing. The water pressure that the casing 32 receives at the top water pressure receiving surface is used for pressure input when the casing 32 is press-fitted into the seabed ground.

  Further, the lower ends of the pair of material supply pipes 21 are connected to the upper part of the casing 32, and the improved material introduced from the material introduction port 23 is guided into the casing 32 through the material supply pipe 21. The compressed air sent from the air pump is sent into the casing 32 through the material supply pipe 21. When the excavating and stirring and mixing unit 29 is submerged in seawater, the seawater can be discharged from the casing 32 by the pressure of the compressed air. That is, a space in which seawater is discharged by air pressure can be secured in the casing 32.

  The lower end of the rod 27 connected to the auger motor 25 is connected to an excavating and stirring mixing blade 35 provided in the casing 32. The excavating / stirring mixing blade 35 is rotationally driven by the power transmitted through the rod 27 and is provided so as to be movable up and down in the casing 32 as shown in FIGS.

  An openable bucket 31 (excavating means) is provided at the tip (lower end) of the casing 32. It can be said that the combination of the casing 32 and the bucket 31 constitutes one casing as a whole. When the bucket 31 is opened, the bottom portion of the casing 32 is opened, and when the bucket 31 is closed, the bottom portion of the casing 32 is closed and sealed. That is, the bucket 31 plays a role as a lid that opens and closes the bottom of the casing 32 (a lid that seals the bottom of the casing 32) in addition to a role as a drilling means for excavating the seabed ground and taking in excavated earth and sand.

Such a bucket 31 (excavation means) has, for example, a hydraulic cylinder as means for opening and closing operations.
A state where the bucket 31 is opened is shown in FIG. In this state, the bottom of the casing 32 is open.
The operation when the bucket 31 is closed from the opened state is shown in FIG. 6B and FIG. Through the series of operations at this time (the operation of closing from the open state), the seabed ground is excavated by the excavation claw at the tip, and excavated soil can be taken into the bucket 31 and the casing 32.
FIG. 6C shows a state where the bucket 31 and the excavating / stirring mixing blade 35 are used together to excavate the seabed ground. In the excavation using the excavating and mixing blades 35, the excavating and mixing blades 35 in the casing 32 are temporarily lowered, and the seabed ground is rotated and excavated in a state of protruding from the opening at the bottom of the casing 32.
A state in which the bucket 31 is closed is shown in FIG. In this state, the bottom of the casing 32 is closed and the casing 32 is sealed. When the excavated earth and sand is taken into the casing 32 and then the bucket 31 is closed, the casing 32 is sealed and the excavated earth and sand is confined in the casing 32.

  The excavating and stirring mixing blade 35 (stirring and mixing means) is provided so as to be movable up and down in the casing 32 as shown in FIG.

The excavating and stirring mixing blade 35 having the above-described configuration is mainly composed of
-Excavated earth and sand taken into the casing 32 by the bucket 31 (excavating means),
An improved material introduced into the casing 32 via a pair of material supply pipes 21 and 21;
Is responsible for stirring and mixing. In other words, the excavating and stirring mixing blade 35 functions as “stirring and mixing means” when stirring and mixing excavated earth and sand or improvement material.
Moreover, as shown in FIG.6 (c), it protrudes from the opening part of the casing 32 bottom part as needed, and bears the role of excavating a seabed ground. That is, the excavating and stirring mixing blade 35 functions as “excavating means” when excavating the seabed ground.
Further, as shown in FIG. 14, if necessary, it plays a role of forcibly extruding a material (for example, modified soil obtained by stirring and mixing excavated earth and improving material) contained in the casing 32 from the casing. ing. That is, the excavating and stirring mixing blade 35 functions as a “material extruding means” when discharging the material accommodated in the casing 32.

(Inside casing pressure control device)
Next, based on FIG. 9, the “inside casing pressure control device” included in the above-described work boat will be described. This pressure control device in the casing functions as a “press-fitting device” when the casing is pressed into the seabed ground, and functions as a “material discharge device” when the material in the casing is discharged in water.

  FIG. 9 is a schematic configuration diagram, a side view, and a front view showing a pressure control device in a casing included in the work boat. In order to easily understand the characteristics of the system configuration, FIG. 9A schematically shows only the main part of the system configuration.

  As will be described later, in this embodiment, one of the features is that compressed air is fed into the casing 32 through the material supply pipe 21 (pressure air pipe) (see step (a) in FIG. 11A). And the casing internal pressure control apparatus of this embodiment plays the role which controls the air pressure (pressure of the compressed air sent in in the casing 32) in a casing.

As shown in FIG. 9, the casing internal pressure control apparatus of the present embodiment mainly includes
An air pump 51 for sending compressed air into the casing 32;
An exhaust passage 53 for controlling the air pressure in the casing 32;
Elevator motor 55 (elevating means) for raising and lowering the exhaust outlet 53 of the exhaust path 53 in water is provided.

  As a whole, the exhaust path 53 is provided so as to guide the air pressure in the casing 32 to the outside of the casing (in seawater). The exhaust passage 53 includes an underwater exhaust pipe 56, an exhaust bypass pipe 57, an exhaust hose 58, and an underwater exhaust pipe valve 59.

  The underwater exhaust port 60 at the tip of the underwater exhaust pipe 56 is in a state of being submerged in seawater during construction using a work boat, and the underwater exhaust pipe 56 is provided so as to be raised and lowered by the lifting motor 55 in this state. Yes. The vertical movement distance of the submerged exhaust pipe 56 is not particularly limited. For example, the submerged exhaust port 60 can be moved vertically (moved in the vertical direction) at a distance within the depth range of the upper end and the lower end of the casing 32. The length of the pipe 56 and the lifting motor 55 are set.

  The exhaust bypass pipe 57 plays a role of guiding the air pressure (compressed air) in the casing 32 to the underwater exhaust pipe 56 outside the casing. One end of the exhaust bypass pipe 57 is connected to the inside of the casing 32 (top end), and the other end is connected to the underwater exhaust pipe 56 via the underwater exhaust pipe valve 59 and the exhaust hose 58.

  The exhaust hose 58 is composed of a flexible pressure-resistant water-resistant hose, one end of which is connected to the underwater exhaust pipe valve 59 and the other end is connected to the underwater exhaust pipe 56. When the underwater exhaust pipe 56 moves up and down, the exhaust hose 58 follows the movement, so that the connection between the two is not disconnected by the operation of the underwater exhaust pipe 56.

  In the above configuration, the compressed air sent from the air pump 51 into the casing 32 is accommodated in the casing and pushes seawater out of the casing by the air pressure.

  The compressed air accommodated in the casing 32 is guided by the exhaust bypass pipe 57 and further guided by the underwater exhaust pipe 56 via the underwater exhaust pipe valve 59 and the exhaust hose 58. Therefore, while the underwater exhaust pipe valve 59 is open and the compressed air is being pumped from the air pump 51, the compressed air in the casing 32 is guided by the exhaust passage 53 and is submerged from the underwater exhaust port 60. Continue to be exhausted.

(Functional action of pressure control device in casing)
Next, based on FIG. 10, the outline of the functional action of the casing internal pressure control device will be described.
FIG. 10 is a diagram illustrating the functional operation of the casing internal pressure control device.

  As shown in FIG. 10, when the underwater exhaust pipe 56 in which the underwater exhaust port 60 is positioned at the depth of the lower end position of the casing 32 is raised by the elevating motor 55, it interlocks with this (follows the rising underwater exhaust port 60. The water level in the casing also rises. Conversely, when the underwater exhaust pipe 56 having the underwater exhaust port 60 positioned at the depth of the upper end position of the casing is lowered by the lifting motor 55, the casing is interlocked with this (so as to follow the descending underwater exhaust port 60). The internal water level also falls. That is, the water level in the casing moves up and down in conjunction with the vertical movement of the underwater exhaust port 60 (underwater exhaust pipe 56).

  Thus, by raising and lowering the exhaust port 60 of the exhaust passage (which communicates with the casing) in water, the air pressure in the casing varies depending on the relative height of the exhaust port 60 with respect to the underwater casing 32. Control of internal pressure is easy. Further, such a function can be realized with a simple device configuration.

  Moreover, seawater inflow into the casing can be easily prevented by the pressure of the compressed air sent into the casing. Further, when seawater has already entered the casing, the seawater in the casing can be discharged out of the casing (extruded by the air pressure) by the air pressure. Therefore, the water level in the casing can be accurately controlled only by raising and lowering the underwater exhaust port 60 (underwater exhaust pipe 56), and the inside of the casing can be easily drained when necessary. When controlling the water level in the casing, the width by which the submerged exhaust port 60 is moved up and down is within the depth range of the upper end and the lower end of the casing 32.

  In each method to be described later, the pressure air from the air pump 51 is used for drainage in the casing. Further, in order to press-fit the casing and take in earth and sand to the casing described later, a force for press-fitting the casing is required. For this pressure input, a water head difference (water bottom ground) generated when the underwater exhaust pipe 56 is pulled up is used. To the underwater exhaust pipe tip). In this case, the pressure difference for the maximum water depth can be used.

(Backfill material input device)
As shown in FIG. 3, the backfilling material charging device 7 is provided so as to be movable up and down along the leader 3, and the backfilling material is placed in the excavation hole generated by the excavation and stirring and mixing device 5 (excavation means). It plays the role of input.

As shown in FIGS. 3 (c) and 5, this backfilling material charging device 7 is
A substantially pipe-like chute 41 for guiding the backfill material;
A backfill material inlet 43 for introducing the improved material into the chute 41;
A chute steadying hardware 45 slidably provided with respect to the reader 3 (FIG. 3 (c)),
have.

  The upper end side of the chute 41 is connected to the wire rope 46. By operating the wire rope 46 in the vertical direction, the entire backfilling material charging device 7 including the chute 41 moves up and down along the leader 3. At that time, the chute steadying hardware 45 is guided by the reader 3 so that the chute 41 does not shake.

  As shown in FIG. 5, the lower end side of the chute 41 is enlarged in diameter when viewed from the front, and the upper end side is branched in a substantially Y shape. A backfill material inlet 43 is provided at each of the upper ends of the chutes 41 branched in a substantially Y shape.

  The backfilling material charging device 7 having the above-described configuration inputs the backfilling material through the chute 41 into the seabed excavation hole generated by the excavation and mixing device 5 and backfills the excavation hole with the backfilling material. Exhibit the function and action.

(Lifting bucket)
As shown in FIG. 3, a leader 3 is erected on the bow side of the work boat 1, and is used for charging materials such as an improved material and a backfill material along a guide rail provided on the side surface of the leader 3. The elevating bucket 9 moves up and down. The elevating bucket 9 plays a role of supplying an improved material to the material input port 23 of the excavating and stirring and mixing device 5 and a backfill material (improved material) to the backfill material input port 43 of the backfill material input device 7. To play a role.

  The raising / lowering bucket 9 is filled with the improvement material / backfill material via the weighing hopper 11. The sand box 13 provided in the work boat 1 contains the improvement / backfill material and is conveyed to the weighing hopper 11 via the belt conveyor 15.

(Example of construction for seabed ground)
Next, as a specific example of the construction method for improving the seabed ground and the seabed environment using the work boat having the above-described features, a submerged dike construction and a shallow place construction will be described. In addition, in this embodiment, a modifier is mentioned as a specific example of the improvement material and backfill material used for construction.

The construction procedure will be specifically described based on FIGS. 11A and 11B.
Steps a to m described below correspond to steps (a) to (m) shown in FIGS. 11A and 11B.

Step a
Compressed air is sent into the casing 32 through the material supply pipe 21, and the seawater in the casing is completely drained to make the inside of the casing hollow. That is, a space without seawater is secured in the casing 32 by air pressure. Thereafter, a completely drained state in which seawater does not flow into the casing 32 by the push-out action of the air pressure is maintained.

Step b
A casing 32 fixed to the lower end of the material supply pipe 21 is abutted against the seabed ground at a predetermined position with the bucket 31 opened.

Process c
With the casing 32 abutting against the seabed ground, the casing is pressed into the ground. The principle of press-fitting the casing will be described later in relation to FIGS.
When the casing is press-fitted, the excavating and stirring mixing blade 35 is lowered as necessary to use as excavation assistance. That is, the excavating and stirring mixing blade 35 is protruded from the opening at the bottom of the casing 32 and is driven to rotate.

Step d
Opening and closing of the bucket 31 (excavating means) at the tip of the casing 32 is repeated, and the excavated earth and sand are taken into the casing 32. In addition, since the inside of the casing 32 is continuously pressurized by compressed air and the completely drained state is maintained after the step a, seawater does not flow into the casing 32 due to water pressure. The same applies thereafter.

Process e
When a necessary amount of excavated earth and sand is taken into the casing 32, the bucket 31 (excavating means) at the tip of the casing is closed. As a result, the casing 32 is sealed, and the excavated earth and sand taken into the casing 32 is isolated from the seawater around the casing.

Process f
With the bottom of the casing 32 (bucket 31) closed, the entire excavation and stirring and mixing unit 29 is pulled out, and a predetermined amount of modifier is introduced into the casing 32 through the material supply pipe 21. Then, while rotating the excavating and stirring and mixing blade 35 in the casing 32, the excavating and mixing blades 35 are moved up and down in the casing 32, so that “the excavated earth and sand taken into the casing 32” and “the reforming material introduced into the casing 32”. Stir and mix. By stirring and mixing them in the casing 32, “reformed soil” is produced in situ, that is, in the casing 32 in water, without being pumped up.

Process g
In order to backfill the excavation hole formed after the excavation and stirring and mixing unit 29 (casing 32) is pulled out, the anchor wire 2 is used to operate the ship, and the lower end of the chute 41 of the backfilling material charging device 7 is directly above the excavation hole. Position to.

Process h
The chute 41 of the backfilling material charging device 7 is lowered to a predetermined position, and the modifying material is charged into the excavation hole through the chute.

Step i
The ship is maneuvered using the anchor wire, and the lower end of the casing 32 is again aligned with the position of the reformer introduced into the excavation hole. The bucket 31 at the lower end of the casing 32 is in a closed state.

Step j
The casing 32 is lowered, and the reforming material thrown into the excavation hole is compressed and compacted by the bucket 31 at the lower end of the casing 32 to increase the supporting force.

Process k
The above-described steps g to j are repeated until the height of the modified material introduced into the excavation hole reaches a predetermined depth (conventional ground height).

Process l
The modified soil obtained by stirring and mixing in the above step f (the material obtained by stirring and mixing the taken excavated earth and the introduced modifying material) is discharged directly above the modifying material filling the drilling hole. To do.
The principle of discharging the modified soil from the casing 32 will be described later in relation to FIG.

Process m
Through the above steps, the construction of submerged dike or shallow ground using the modified soil is completed.
The constructed submerged dike and the constructed shallow ground are provided so as to cover the top of the reforming material (consolidated reforming material) that fills the excavation hole, as shown in step (m) of FIG. 11B. And modified soil. The modified soil is a material produced in seawater (inside the casing 32 from which the seawater has been discharged) by effectively utilizing the original excavated soil.

(Method of press-fitting casing into submarine ground / Method of taking up sediment from submarine ground)
Next, the casing press-fitting method in steps (b) and (c) of FIG. 11A will be described more specifically based on FIGS.
12 (b) and 12 (c) are process diagrams corresponding to the processes (b) and (c) of FIG. 11A and showing the principle of casing press-fitting.
FIGS. 13 (b), (c1), and (c2) are process diagrams corresponding to the processes (b) and (c) of FIG. 11A, and show the casing press-fitting principle in more detail.

In the present embodiment, the casing is press-fitted into a predetermined position of the seabed ground using the above-described casing pressure control device (press-fitting device). The soil quality of the seabed ground is not particularly limited. For example, it is possible to press-fit the casing into the clay soil ground.
The specific press-fitting method is as follows.

  In press-fitting the casing 32, the submerged exhaust port 60 of the pressure control device in the casing is positioned in advance at the depth of the lower end position of the casing. Thereby, the water level in a casing follows the depth of the underwater exhaust port 60, and falls to a casing lower end position. As a result, the inside of the casing is filled with compressed air, and the pressure of the compressed air prevents seawater from flowing into the casing. That is, the casing 32 is completely drained by aligning the depth of the lower end of the casing and the underwater exhaust port 60 underwater. Excess compressed air exceeding the capacity in the casing 32 is exhausted into the water from the underwater exhaust port 60 through the underwater exhaust pipe 56 as shown in FIG.

When the state in which the inflow of seawater into the casing 32 is thus prevented is secured, the lower end of the casing is then brought into contact with the seabed as shown in FIG. Thereby, the lower opening part of the casing 32 will be in the state where it was block | closed by the seabed ground (cohesive soil) without gap.
FIG. 12 (b) shows a state where the lower end of the casing 32 filled with compressed air is exactly abutted against the seabed ground with the bucket 31 opened with no gap. In this state, as shown in FIG. 13 (b), the water pressure and earth pressure acting on the casing 32 and the casing internal pressure are balanced.

  Next, in a state in which the seawater is prevented from flowing into the casing 32 by the compressed air, and the lower end of the casing 32 is in contact with the seabed (a state in which the lower opening of the casing 32 is blocked by the seabed ground). ), The underwater exhaust pipe 56 is pulled up to raise the underwater exhaust port 60. That is, the underwater exhaust port 60 is raised relative to the casing 32. Then, as shown in FIG. 13 (c1), the compressed air in the casing 32 is discharged to the outside of the casing through the underwater exhaust pipe 56. As a result, the air pressure in the casing 32 is reduced, and a negative pressure is generated in the casing. Will occur. As a result, the balance between the water pressure and earth pressure acting on the casing 32 and the air pressure inside the casing is lost, and the water pressure acting on the casing 32 becomes dominant. That is, as shown in FIG. 13 (c1), by pulling up the underwater exhaust pipe 56, the air pressure in the casing rapidly decreases, and as a result, the water pressure acting on the casing 32 becomes a pressure input and the casing 32 moves in the press-fitting direction. Pushed forward.

  Therefore, by using the casing internal pressure control device and pulling up the underwater exhaust pipe 56 as shown in FIG. 12 (c), the casing can be press-fitted into the target ground using the water pressure. In this casing press-fitting method, the negative pressure generated in the casing and the water pressure (pressure input) acting on the casing can provide a maximum water depth as shown in FIG. 13 (c2).

  If the casing 32 can be press-fitted into the ground in this way, the seabed ground relatively enters the casing, so that the sediment of the seabed ground can be taken into the casing. Therefore, the casing internal pressure control device can be used by a method of press-fitting the casing into the seabed ground, and can also be used by a method of taking the earth and sand of the seabed ground into the casing.

(Material discharge method in water)
Next, the material discharging method in the steps (l) and (m) of FIG. 11B will be specifically described based on FIG.
14 (l) (m) is a process diagram corresponding to the process (l) (m) in FIG. 11B and shows the principle of material discharge.

In the present embodiment, the above-described casing pressure control device (material discharge device) is used to discharge the modified soil as the material from the casing.
The specific material discharge method is as follows.

  First, the casing 32 containing the modified soil as a material is positioned at a modified soil discharge position in water (for example, directly above the modified material filling the excavation hole). The modified soil contained in the casing is the modified soil obtained by stirring and mixing in the step f (the mixed soil of excavated soil and modifying material).

  At this time, the underwater exhaust port 60 of the casing internal pressure control device is positioned at the depth of the lower end position of the casing 32. Therefore, the inside of the casing 32 is filled with compressed air, and the inflow of seawater into the casing 32 is hindered by the pressure of the compressed air. In other words, the depth of the lower end of the casing 32 and the depth of the underwater exhaust port 60 are aligned, so that the casing is completely drained. Thereafter, this drainage state continues.

  Subsequently, as shown in FIG. 14 (l), the bucket 31 at the lower end of the casing is opened in a state where the inflow of seawater into the casing 32 is blocked by the compressed air. In addition, the modified soil accommodated in the casing 32 in this embodiment is a mixture obtained by stirring and mixing viscous excavated soil and modifying material. Therefore, it is assumed that the modified soil in the casing 32 is viscous and sticks to the inner wall of the casing 32.

  Therefore, in the present embodiment, the modified soil in the casing 32 is pressed in the discharge direction with the compressed air in the casing, and as shown in FIG. 14 (m), the excavating and stirring mixing blade 35 (material pushing means) is provided. The modified soil is lowered in the casing 32 and mechanically pressed in the discharge direction. As a result, the modified soil in the casing 32 is subjected to a double pushing action of the compressed air and the excavating / stirring mixing blade, and is forcibly discharged from the lower end of the casing.

  When all the reformed soil in the casing 32 is discharged, the bucket 31 at the lower end of the casing is closed again, and the reformed soil discharged onto the ground by the casing is pushed in this state as shown in FIG. Crush.

(Musubi)
Finally, the above-described embodiment is an exemplification of the present invention described in the claims, and the form of the present invention is not necessarily limited thereto. That is, in the above-described embodiment, “submarine dike” and “shallow ground” are given as specific examples of construction methods for improving the seabed ground and the seafloor environment, but these are improvements in the seabed ground. It is an illustration of a construction method for improving the seafloor environment, and the technical scope of the present invention is not limited to these embodiments.

  The work boat illustrated in the above-described embodiment is an example of work equipment that can be used for carrying out the present invention, and the present invention can be carried out without such a hull. That is, in the above-described embodiment, the hull is used, but instead of this, for example, necessary equipment such as a press-fitting device and a pressure control device in the casing is attached to a mobile heavy machine prepared on land, and the submarine ground from the land. It is also possible to carry out various constructions such as improving the seabed and the seabed environment. In addition, when construction is performed using such heavy equipment prepared on land, it is possible to install the heavy equipment on a revetment or a pier and perform operations such as press-fitting casings toward the seabed.

  In addition, the application of the present invention is not limited to the improvement of the seabed ground, but can also be used to improve the ground of the riverbed and the ground of the lakebed.

1 Work ship (ground improvement ship)
2 Anchor wire 3 Leader 5 Excavation and stirring mixing device 7 Backfill material input device 9 Lifting bucket 11 Weighing hopper 13 Sand box (material storage box)
15 Belt conveyor 21 Material supply pipe (material feed path / flow path / pipe for pressurized air)
23 Material input (material input)
25 Auger motor (rotary drive)
26 Wire rope 27 Rod 29 Excavation and stirring mixing section (stirring mixing means)
31 bucket (drilling means)
32 Casing 35 Excavation / Agitation Mixing Blade (Excavation Means / Agitation Mixing Means / Material Extrusion Means)
41 Chute 43 Backfill material input (material input)
45 Chute steady rest metal 46 Wire rope 51 Air pump 53 Exhaust passage 55 Lifting motor (lifting means)
56 Underwater exhaust pipe 57 Exhaust bypass pipe 58 Exhaust hose 59 Underwater exhaust pipe valve 60 Underwater exhaust port

Claims (5)

A pump for sending compressed air into the underwater casing;
An exhaust path provided to guide the air pressure in the underwater casing to the outside;
Elevating means for raising and lowering the exhaust port of the exhaust path;
A method of press-fitting a casing into a water bottom ground using a pressure control device in the casing comprising:
Pressurize the inside of the casing with compressed air to prevent the inflow of water into the casing, and make sure that the bottom end of the casing is closed to the bottom so that the bottom end opening of the casing is blocked by the bottom of the ground. A contact process;
A step of raising the exhaust port of the exhaust passage in a state where the inflow of water into the casing is prevented by compressed air and the lower end of the casing is in contact with the bottom of the water .
A method of press- fitting into a water-bottomed ground, wherein a negative pressure is generated in the casing by raising an exhaust port of the exhaust passage, and as a result, the casing is press-fitted into the water-floored ground. A pump for sending compressed air into the underwater casing;
An exhaust path provided to guide the air pressure in the underwater casing to the outside;
Elevating means for raising and lowering the exhaust port of the exhaust path;
Using a pressure control device in a casing comprising the following:
Pressurize the inside of the casing with compressed air to prevent the inflow of water into the casing, and make sure that the bottom end of the casing is closed to the bottom so that the bottom end opening of the casing is blocked by the bottom of the ground. A contact process;
A step of raising the exhaust port of the exhaust passage in a state where the inflow of water into the casing is prevented by compressed air and the lower end of the casing is in contact with the bottom of the water .
Raising the exhaust port of the exhaust passage generates a negative pressure in the casing, and as a result, the bottom sediment is taken into the casing . A method for discharging a material comprising earth and sand taken into a casing by the method according to claim 2 from the casing in water,
A pump that sends compressed air into the underwater casing;
A material extruding means provided so as to be raised and lowered in the casing;
A method for discharging the material in the casing in water using
Positioning the casing containing the material at a material discharge position in water;
A step of pressing the material in the casing in the discharge direction by the compressed air in the casing and the material extruding means in a state in which the inflow of water into the casing is prevented by the compressed air;
A method for discharging material in water, comprising: The casing has a bucket capable of opening and closing the lower end opening of the casing,
The method for discharging a material in water according to claim 3 , further comprising a step of crushing the material discharged to the bottom ground by the casing in a state where the bucket is closed. An apparatus for press-fitting a casing into a submarine ground used in the method according to any one of claims 1 to 4 ,
A pump for sending compressed air into the underwater casing;
An exhaust passage for guiding the air pressure in the underwater casing to the outside of the casing;
Press-fitting apparatus for underwater ground, characterized by comprising, an elevating means for raising and lowering the exhaust port of the exhaust passage.