JPH09195281A - Method of installing caisson on sea - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely perform a work for installing a caisson in a position having a proper distance from a bottomed caisson bottomed on a foundation riprap on the sea bottom in a short time. SOLUTION: An installing caisson 2 is situated in the state where its bottom part 2a is separated from a foundation riprap 6 on the sea near a bottomed caisson 1 bottomed on the foundation riprap 6. Caisson moving means 3 set on the bottomed caisson 1 and the installing caisson 2 are laid in operable state, and two or more air bags 4b of a shock absorber 4 are suspended from the upper surface of the bottomed caisson 1 to the side wall 1b opposed to the installing caisson 2 and made into high pressure. The installing caisson 2 is lowered by water injection, pulled to the bottomed caisson 1 side by the caisson moving means 3, and brought into contact with the air bags 4b, the position of the installing caisson 2 is moved and corrected by the caisson moving means 3 while adjusting the pressures within the air bags 4b. Thereafter, the installing caisson 2 is bottomed by water injection, and the air bags 4b are then contracted and lifted up.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foundation rubble laid on the seabed with a caisson made of concrete or steel used for breakwaters, quays, seawalls, mooring facilities, jetties, breakwaters, etc. When installing sequentially on top, the existing caisson (hereinafter,
Safely and quickly install a caisson to be installed next (hereinafter sometimes simply referred to as an installation caisson) at a predetermined position adjacent to the bottom caisson while preventing a collision with the bottom caisson. It relates to a caisson installation method that can be done at sea.

[0002]

2. Description of the Related Art To construct a breakwater, a quay wall, a seawall, a mooring facility, a jetty, a breakwater, etc. by using a caisson made of concrete or steel with a closed bottom, rubble is placed at a predetermined position on the seabed. To form a foundation rubble, place the bottom of the manufactured caisson on the foundation rubble at a specified position, and then place the bottom caisson on the bottom of the caisson. The installation caisson, which is to be installed next at spaced intervals, is installed on the foundation rubble by bottoming and installing it.

The general work for installing the installation caisson adjacent to the bottom caisson is, as shown in the flow sheet of FIG. 6, first, the installation caisson is placed in the vicinity of the position to be installed in a floating state on the sea. Towed to the sea area of. Then, after the towed installation caisson is brought close to the bottom caisson to a certain extent, the caisson moving means is made operable. As this caisson moving means, for example, a winch installed on an installation caisson or a bottom caisson and an end part connected to the bottom caisson or the installation caisson on the side opposite to the caisson on which this winch is installed are connected to a pulley. A pulling wire rope that is wound and unwound onto the winch via an anchor wire rope that is wound and unwound on the winch installed at the installation caisson or bottom caisson and has one end locked to the seabed. And a winch installed on the installation caisson or the bottom caisson, and a pulley installed on the bottom caisson or the installation caisson opposite to the caisson on which the winch is installed, and one end An anchoring wire rope that is locked on the seabed and is wound around and unwound from the winch via the pulley. It can be exemplified embodiment comprises and. Then, the winch of the caisson moving means is operated to move the installation caisson with respect to the bottom caisson so as to be positioned at a proper distance. When this installation caisson is moved to the bottom caisson side, by pouring water (primary water injection) into the inside surrounded by the side wall of the installation caisson and the closed bottom, the bottom of the caisson can be properly adjusted from the top surface of the foundation rubble. Let the installation caisson settle until it is located a distance away. After that, precise positioning and confirmation of the installation position are performed, and water is further injected into the installation caisson (secondary water injection) so that the installation caisson still in a floating state is bottomed on the foundation rubble. The caisson thus installed and the caisson moving means installed on the bottom caisson are removed to complete the caisson installation. This series of operations is performed at once in good weather conditions, that is, when the wind is weak and the waves are quiet.

As the caisson moving means, in addition to the above-mentioned mode, a hoisting ship 7 having a winch 3a as shown in FIG. 8 is used, and one end of the caisson 1 is connected to the bottom caisson 1. The wire rope 3c is wound around the winch 3a of the hoist ship 7 via the pulley 3b provided on the installation caisson 2.
A pulley in which a pulling wire rope whose one end is connected to an installation caisson is provided on the bottom caisson by using a hoisting ship in which a winch is also installed (not shown). There are various modes such as being mounted on a winch of a hoist ship so as to be able to be wound and unwound freely. In the case of these modes, the side opposite to the bottom caisson 1 and the normal line to the normal installation caisson 2 are usually used. A tugboat 9 is arranged around the installation caisson 2 in a direction orthogonal to 10, and the tugboat 9 and the installation caisson 2 are connected by a rope. Then, the work of moving the installation caisson 2 while pulling by the tugboat 9 is performed. Here, for example, when the buoyancy of the installation caisson 2 is small, the hoisting ship 7 with the crane 8 installed is used to suspend the end of the installation caisson 2 as shown in FIG. Wire rope
8a is hooked on the hook of the crane 8 so that the installation caisson 2 is suspended, and the installation caisson 2 is located in a predetermined sea area where the caisson 2 should be installed, or it is settled by a crane operation and settled on the foundation rubble 6. Sometimes work is done.

Even if the caisson installation work as described above is performed at sea even when the weather conditions are good, the installation caisson 2 that is floating is always swinging in all directions. Installation caisson 2 is the bottom caisson 1 when 2 is close to the bottom caisson 1.
Since there is a risk that they will collide with each other and be damaged, the cushioning material 5 is placed on the side wall 1b of the bottom caisson 1 facing the installation caisson 2 as shown in FIGS. It was extremely important to prevent

[0006] Conventionally, as the cushioning material 5 for preventing the damage due to the collision of the caisson, a square bar (wood), a rubber fender, a rubber tire, etc. have been used, and a worker can be suspended by a rope or the like. The cushioning material 5 was suspended from the upper end of the bottom caisson 1 by gripping it at a predetermined position on the bottom caisson 1. That is, since the installation caisson 2 is installed at a predetermined interval with respect to the bottom caisson 1, the cushioning material 5 having a width substantially equal to the predetermined interval is placed at a predetermined position on the bottom caisson by suspending means such as a rope. After the installation caisson 2 was precisely positioned and confirmed / corrected in a state of being suspended from the upper end of 1, the installation caisson 2 was bottomed on the foundation rubble 6, and the cushioning material 5 was removed by an operator.

However, as described above, the installation caisson 2 is always swinging in all directions, and the position adjustment of the installation caisson 2 is performed by winding and unwinding the winch, so that the installation caisson 2 should be installed without any misalignment. It is difficult. Therefore, when the installation caisson 2 is pulled too close to the bottom caisson 1 side by the winch, the cushioning material 5 is strongly held between the installation caisson 2 and the bottom caisson 1 and the cushioning material 5 cannot be pulled up. It was In such a case, if the installed caisson 2 installed with high precision is drained of the water inside or suspended by the crane 8, the caisson moving means removes the cushioning material 5 after floating it slightly by operating the crane. The caisson 1 is moved to the opposite side to the extent that it can be removed, and the cushioning material 5 is removed, and then water is poured or the crane operation is performed again to reach the bottom. The position of the caisson 2 may be displaced when it is moved, and it takes a long time to accurately set the caisson 2 to a predetermined position and set it down.

Further, on the bottom caisson 1, members such as wire ropes, anchor wire ropes, winches, pulleys, and the like that constitute the caisson moving means, and pumps and other mechanical devices for injecting or draining seawater into the installed caisson 2 are installed. Is provided and is in a complicated state, and since the operator holds the cushioning material 5 by the suspending means on the bottom caisson 1 as described above, the cushioning material 5 is provided between the installation caisson 2 and the bottom caisson 1. When the force to hold the cushioning material 5 suddenly weakens due to the influence of swelling while the material 5 is being held and the operator is firmly gripping the suspending means, the operator is recoiled by the reaction. Loses balance and trips over complicated machinery, falls and floats. Installation caisson 2
There was a drawback that it was very dangerous because it fell into the sea between the bottom and the bottom caisson 1.

[0009]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art, and next installs it at a predetermined space adjacent to an existing caisson on the foundation rubble on the seabed. It is an object of the present invention to provide a method of installing a caisson on the sea, which allows a caisson to be bottomed safely and in a short time.

[0010]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the inventors of the present invention have found that the bottom of the caisson is bottomed on a rubble foundation laid on the seabed. After locating the installation caisson on the sea in a state in which the bottom part is separated from the foundation rubble, when moving the installation caisson to a position at a predetermined distance from the bottom caisson to settle on the foundation rubble, In order to move the caisson moving means installed in the bottom caisson and the installation caisson, the pressure adjusting means and the internal pressure are adjusted by the pressure adjusting means to install the installation caisson from the bottom caisson. A bladder having a bladder formed with a caisson abutting portion wider than a predetermined interval, the bladder being provided on a side wall facing the installation caisson from an upper surface of the bottom caisson. Two or more pieces are hung from each other and a high pressure is applied to the inside to sink the installed caisson until the bottom of the caisson is located near the foundation rubble, and the caisson moving means pulls the installed caisson to the bottom caisson side to absorb the shock. After adjusting the pressure inside the air bladder from the state of contacting it with the air bladder, the position of the installation caisson is corrected by moving the caisson moving means, and then the bottom of the installation caisson is placed on the foundation rubble and bottoms. Until the installation caisson is settled, and then the pressure inside the bladder is reduced by the pressure adjusting means to contract the bladder, and then the bladder is pulled up, then it should be installed at a position spaced a predetermined distance from the bottom caisson. The present invention has been completed by investigating that the work of mounting the installation caisson on the bottom can be performed safely and quickly.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A caisson installation method according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a front explanatory view showing a shock absorber preferably used in the method of the present invention, FIG. 2 is a perspective view showing an example of a concrete caisson used in the method of the present invention, and FIG. 3 is a caisson on a foundation rubble. It shows the installed state (a)
Is a side view and (b) is a plan view, and FIG. 4 shows a process of carrying out the method of the present invention. A caisson moving means is installed between the installation caisson and the bottom caisson floating near the bottom caisson. (A) is a side explanatory view, (b) is a plan explanatory view, and FIG. 5 shows the method of the present invention when the air bag of the shock absorber is suspended from the upper part of the bottom caisson. FIG. 7B is a side view and FIG. 8B is a plan view showing a state in which the installation caisson is moved to the bottom caisson side by the caisson moving means and the positioning is performed.

In the drawings, 1 is a bottom caisson in which a bottom portion 1a is preliminarily bottomed on a foundation rubble 6 laid on the seabed, 2
Like the bottom caisson 1, the bottom part 2a is located on the foundation rubble 6 at a position adjacent to the bottom bottom caisson 1 and at a predetermined interval.
It is an installation caisson that is placed and bottomed. The bottom caisson 1 and the installation caisson 2 are made of concrete or steel plate, and at least opposing side walls 1b and 2b are formed flat as shown in FIG.
Partitions 1c and 2c are formed over the entire height in a space surrounded by 2b, and bottoms 1a and 2a are closed.

Reference numeral 3 designates an installation caisson 2 which is positioned with the bottom portion 2a thereof separated from the foundation rubble 6, and a bottom caisson 1 is attached.
It is a caisson moving means for moving to the side or correcting the position in the direction of the normal 10 so that the side surface of the bottom caisson 1 and the side surface thereof form a straight line. Can be used, the description thereof will be omitted.

Reference numeral 4 is a pressure adjusting means 4a and this pressure adjusting means 4a.
An air bag made of a soft material that is expanded and contracted by supplying and discharging air to increase and decrease its volume.
4b and a shock absorber. The air bag 4b has a caisson abutting portion 4bc wider than a predetermined interval at which the bottom caisson 1 to the installation caisson 2 are installed in a state where air is supplied and the inside thereof is inflated to a high pressure. Further, a rope 4bd is attached to the air bag 4b in order to suspend the air bag 4b from above the bottom caisson 1 and pull up the air bag 4b after the bottom caisson 1 bottoms.

As a material for forming the air bag 4b, the air bag 4b is pressed between the bottom caisson 1 and the installation caisson 2 as will be described later, and even if the caisson is small 1, Since it has a weight of about 000 tons, any one can be used as long as it has a strength to withstand when pressed by the bottom caisson 1 and the installation caisson 2 and the volume can be increased or decreased. Furthermore, since it is used by being suspended at a position near the sea surface, and the installation caisson 2 is set on the predetermined position and then pulled up by the operator,
If the material absorbs water, the weight of the air bladder 4b increases and the burden on the operator when pulling up the air bag 4b increases. Therefore, it is preferable that the material does not absorb water. In consideration of these, it is preferable that the air bag 4b is made of various kinds of rubber or the like. As shown in FIG. 1, the air bag 4b has a rubber body in which a reinforcing material such as a nylon cord is embedded in a rubber body. The band 4bb may be provided at intervals in the vertical direction and the horizontal direction, respectively.

Further, a member for reducing the frictional resistance generated when the surface and the caisson are in contact with each other, such as a plate made of fluororesin, is fixed to the caisson contact portion 4bc of the air bag 4b. It is preferable that the air bag 4b is prevented from being damaged or that a paint mixed with powder of molybdenum disulfide is applied.

As the pressure adjusting means 4a, the compressor 4a
a, this compressor 4aa at one end and air bag 4b at the other end
An air supply flexible tube 4ab connected to, a pressure gauge 4ac for detecting the pressure in the air bladder 4b, and a valve 4ad for exhausting the air in the air bladder 4b. Can be mentioned.

In order to carry out the method of the present invention and set the installation caisson 2 on the foundation rubble 6 at a position spaced by a predetermined distance adjacent to the bottom caisson 2, the installation caisson 2 is first set to a predetermined position. The installation caisson 2 is located at a position, that is, in the vicinity of the bottom caisson 1 that has already been bottomed and the installation caisson 2 is next installed next to the caisson. The installation caisson 2 to be installed from the temporary storage area where the crane is placed is towed to the above-mentioned predetermined position by a tug in a floating state, or is suspended on this crane 8 using the hoist ship 7 on which the crane 8 is installed. The hoist ship 7 is made to sail and carried to the predetermined position while being suspended via the lower wire rope 8a.

Pressure adjusting means is provided on the bottom caisson 1.
4a is installed and the inside of the air bag 4b is made high in pressure by the pressure adjusting means 4a so that the caisson contact portion 4bc is formed with a space between the bottom caisson 1 and the side wall 1b facing the installation caisson 2. 2 or more, and the shock absorber 4 is installed in the bottom caisson 1. To suspend the air bag 4b, a hanging metal fitting may be fixed to the bottom caisson 1, and the rope 4bd attached to the air bag 4b may be fixed to the hanging metal fitting. Further, a caisson moving means 3 for moving the installation caisson 2 which is located in the vicinity of the bottom caisson 1 and whose bottom portion 2a is away from the foundation rubble 6 is installed.

Next, in order to move the installation caisson 2, the caisson moving means 3 installed in the bottom caisson 1 and the installation caisson 2 is made operable, and the caisson moving means 3 bottoms the installation caisson 2. Caisson 1
At this time, when the installation caisson 2 is towed as described above, the installation caisson 2 is in a relatively shallow floating state in order to reduce the resistance of water acting on the installation caisson 2. When the primary water is injected into the space surrounded by the side wall 2b of the above, and when the crane 8 is suspended, the crane 8 is operated to locate the bottom 2a near the foundation rubble 6 Let it settle. In this way, the operation to settle or float the installation caisson 2 is performed by pouring water into the installation caisson.
It is performed by draining water or operating the crane 8, and may be simply referred to as sedimentation or floating.

Then, the installation caisson 2 is attached to the bottom caisson 1
The installation caisson 2 and the bottom caisson 1 are held at a wider distance than the predetermined distance while being pulled toward the side and brought into contact with the air bag 4b of the shock absorber 4. From this state, the position of the installation caisson 2 in the direction of the normal 10 is moved and corrected by the caisson moving means 3, and the bottom caisson 1 of the installation caisson 2 is fixed.
The installation caisson 2 is moved and corrected by the caisson moving means 3 while adjusting the pressure in the air bladder 4b by the pressure adjusting means 4a so that the distance from is a predetermined distance. At this time, the installation caisson 2 is pulled toward the bottom caisson 1 by the caisson moving means 3 with a certain amount of force.

After that, the bottom portion 2a of the installation caisson 2 is placed on the foundation rubble 6 and settled until it reaches the bottom, and when the installation of the installation caisson 2 is completed, the pressure in the air bag 4b is adjusted by the pressure adjusting means 4a. The entire work is completed by lowering the air bag 4b to shrink it and then pulling it up.

[0023]

By carrying out the method of the present invention as described above, the installation caisson 2 is bottomed at a position which is adjacent to the bottom caisson 1 already bottomed on the foundation rubble 6 and is separated by a predetermined distance. When the installation caisson 2 is located near the bottom caisson 1 and floats, the installation caisson 2 is swung in all directions under the influence of waves when moved to the bottom caisson 1 side. It also swings to the bottom caisson 1 side, but since the air bag 4b of the shock absorber 4 is hung on the side wall 1b of the bottom caisson 1 facing the installation caisson 2, the installation caisson 2 is the bottom caisson. It is prevented from hitting the 1 and can be installed without damaging the very expensive caisson.

Further, the air bag 4b of the shock absorber 4 has a caisson contact portion 4bc wider than a predetermined space at which the bottom caisson 1 to the installation caisson 2 are installed in a state where the air bag 4b is inflated by being supplied with air. , The distance between the installation caisson 2 and the bottom caisson 1 can be adjusted and held to some extent until the installation caisson 2 is bottomed by adjusting the pressure in the air bag 4b of the shock absorber 4. The valve 4ad of the pressure adjusting means 4a of the shock absorber 4 is opened to discharge the air in the air bladder 4b to lower the pressure, thereby reducing the volume in the air bladder 4b and reducing the distance between the installation caisson 2 and the bottom caisson 1. Can be modified to be narrower. That is,
Since two or more air bladders 4b of the shock absorber 4 are hung at intervals, one side of the installation caisson 2 is in contact with the air bladders 4b at an angle deviated from the normal line 10. By adjusting the pressure inside the air bag 4b (on the side where the distance between the bottom caisson 1 and the installation caisson 2 is wide) to be low as described above, the distance between the installation caisson 2 and the bottom caisson 1 is adjusted to correct the angle. can do.

Further, since the air bag 4b of the shock absorber 4 is made of a soft material, the air in the air bag 4b is discharged to reduce the pressure so that the bottom caisson 1 is placed on the foundation rubble 6. After bottoming the bottom, the air bag 4b can be easily pulled up from the gap between the bottom caisson 1 and the installation caisson 2. Therefore, the air bag 4b of the shock absorber 4 can be repeatedly used, which is economical. If the caisson abutting portion 4bc of the air bag 4b of the shock absorber 4 is provided with a member for reducing frictional resistance, the air bag 4b can be prevented from being damaged and the life of the air bag 4b can be extended. It is more economical to do so.

The air bag 4b of the shock absorber 4 need not be supported by the operator if it is hung from a hanging metal fitting on the bottom caisson 1 with a rope, and the pressure in the air bag 4b is adjusted. The pressure adjusting means 4a can be operated from this position by installing the pressure adjusting means 4a at a position distant from the side wall, so that the operator falls to the sea between the bottom caisson 1 and the installation caisson 2. It is very safe without doing.

As described above, the method of installing a caisson on the sea according to the present invention, which exhibits various effects, is of great industrial value.

[Brief description of the drawings]

FIG. 1 is a front explanatory view showing a shock absorber preferably used in the method of the present invention.

FIG. 2 is a perspective view showing an example of a concrete caisson used in the method of the present invention.

FIG. 3 shows a state in which a caisson is installed on a foundation rubble, (a) is a side view and (b) is a plan view.

FIG. 4 shows a process in which the method of the present invention is carried out, in which the caisson moving means is set in an operable state with the installation caisson and the bottom caisson floating near the bottom caisson, and the air bag of the shock absorber is installed. (A) is a side explanatory view and (B) is a plan explanatory view showing a state of being suspended from the upper part of the bottom caisson.

FIG. 5 shows a process for carrying out the method of the invention,
Shows a state in which the installation caisson is moved to the bottom caisson side and positioned by the caisson moving means.
(A) is a side view and (B) is a plan view.

FIG. 6 is a flow sheet illustrating a series of operations for installing an installation caisson, which is to be installed next on the bottom caisson at a predetermined interval.

FIG. 7 is a side view showing a state where installation work is performed by using a conventional cushioning material to prevent direct contact between the installation caisson and the bottom caisson.

FIG. 8 is an explanatory plan view showing caisson moving means.

FIG. 9 is a front explanatory view showing a state where an installation caisson is suspended by a crane installed on a hoist ship.

[Explanation of symbols]

 1 bottom caisson 1a bottom 1b side wall 1c bulkhead 2 installation caisson 2a bottom 2b side wall 2c bulkhead 3 caisson moving means 3a winch 3b pulley 3c pulling wire rope 3d anchor wire rope 4 shock absorber 4a pressure adjusting means 4aa compressor 4ab air supply possible Flexible tube 4ac Pressure gauge 4ad Valve 4b Air bag 4ba Main body 4bb Reinforcement band 4bc Caisson contact part 4bd Rope 5 Buffer material 6 Foundation rubble 7 Hoist ship 8 Crane 8a Suspended wire rope 9 Towboat 10 Normal line

Front Page Continuation (72) Masao Shiga Inventor Masao Shiga 65 Sakaemachi, Onahama, Iwaki, Fukushima Prefecture Onboard Harbor Construction Office, Second Port Construction Bureau, Ministry of Transportation (72) Tokio Naganuma 2-10 Honmachi, Aoba-ku, Sendai City, Miyagi Prefecture Of 28 Wakatsuki Construction Co., Ltd.

Claims (3)

[Claims] 1. A bottom caisson (1) is pre-bottomed on a foundation rubble (6) laid on the sea floor. The foundation rubble (6)
After placing it away from the bottom caisson (1)
To a position separated by a predetermined distance from the foundation rubble
(6) When the bottom caisson (2) is moved to the bottom, the caisson moving means (3) installed on the bottom caisson (1) and the installation caisson (2) is moved so as to move. Along with the pressure adjusting means (4a), the internal pressure is adjusted by the pressure adjusting means (4a) so that the installation caisson (2) is installed from the bottom caisson (1). The air bag (4b) of the shock absorber (4) provided with the air bag (4b) formed on the side wall (1b) facing the installation caisson (2) from the upper surface of the bottom caisson (1). Suspend two or more pieces at a distance to make the inside high pressure, and let the installation caisson (2) settle until its bottom (2a) is located near the foundation rubble (6), and by means of the caisson moving means (3). The state where the installation caisson (2) is pulled toward the bottom caisson (1) side and brought into contact with the air bag (4b) of the shock absorber (4). After adjusting the pressure in the air bag (4b) to move and correct the position of the installation caisson (2) by the caisson moving means (3), the bottom part (2a) of the installation caisson (2) is replaced with a foundation rubble (6). ) The installation caisson (2) is allowed to settle until it is placed on the bottom and bottomed, and then the pressure inside the air bladder (4b) is reduced by the pressure adjusting means (4a), and then the air bladder (4b) is contracted. A caisson installation method at sea, which is characterized by pulling up afterwards. 2. A rubber body (4ba) as the air bag (4b)
The method for installing a caisson at sea according to claim 1, wherein a reinforcing band (4bb) is provided around the peripheral surface of the caisson. 3. The air bag (4b) serves as a caisson contact portion (4).
The method for installing a caisson on the sea according to claim 1 or 2, wherein a member for reducing frictional resistance generated between the caisson and bc) is provided.