JP3754985B2 - Caisson installation method at sea - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is used for a breakwater, a quay, a revetment, a mooring facility, a jetty, a breakwater, etc., when a concrete or steel caisson with a closed bottom is sequentially installed on a foundation rubble laid on the seabed, Next to a predetermined position adjacent to the bottom caisson safely and quickly, while preventing collision with an existing caisson (hereinafter sometimes referred to as a bottom caisson) that has been grounded on the rubble in advance. The present invention relates to a method for installing a caisson on the sea where a caisson to be installed (hereinafter sometimes simply referred to as an installation caisson) can be installed.
[0002]
[Prior art]
To construct a breakwater, quay, revetment, mooring facility, jetty, breakwater, etc. using a concrete or steel caisson with a closed bottom, rubble at a predetermined position on the bottom of the sea. The bottom of the manufactured caisson is grounded so as to be placed at a predetermined position on the foundation rubble, and then is positioned adjacent to the bottomed bottom caisson at an appropriate interval. Next, the work of installing the installation caisson, which is to be installed next, on the foundation rubble, is repeated sequentially.
[0003]
The general operation for installing the installation caisson adjacent to the bottom caisson is as shown in the flow sheet in FIG.
(1) First, the towed vessel is towed to a predetermined sea area near the position where the installation caisson is suspended in the sea.
{Circle around (2)} After the towing installation caisson is brought close to the bottom caisson to a certain extent, the caisson moving means is brought into an operable state. As the caisson moving means, for example, a winch installed in an installed caisson or a bottomed caisson, and an end connected to the bottomed caisson or installed caisson on the opposite side of the caisson where the winch is installed and a pulley is used. Wire rope for winding and unwinding to the winch through, and an anchor wire rope wound on and unwound to the winch installed at the installation caisson or the landing caisson, one end of which is locked to the seabed A winch installed in the installation caisson or the bottom caisson, a pulley provided in the bottom caisson or the installation caisson opposite to the caisson in which the winch is installed, and one end of the winch An attracting wire rope / anchor wire rope that is locked to the seabed and wound and unwound on the winch via the pulley It can be exemplified embodiment comprises and.
(3) Next, the winch of the caisson moving means is operated to move the installation caisson so as to be positioned at an appropriate distance from the bottom caisson.
(4) When this installation caisson is moved to the bottom caisson side, water is poured into the interior surrounded by the side wall of the installation caisson and the closed bottom (primary water injection), so that the bottom is the top surface of the foundation rubble. The settling caisson is allowed to settle until it is located at a suitable distance from.
{Circle around (5)} After that, the installation position is precisely positioned and confirmed, and further, water is injected into the installation caisson (secondary water injection), and the installation caisson that is still floating is settled on the foundation rubble.
(6) The installation of the caisson is completed by removing the equipment such as the caisson moving means installed in the caisson thus installed and the bottom caisson.
A series of these operations is performed at a time when the weather conditions are good, that is, when the wind is weak and the waves are quiet.
[0004]
As the caisson moving means, in addition to the above-described embodiment, a hoisting ship 7 in which a winch 3a is installed as shown in FIG. 8 is used, and a drawing wire rope 3c connected at one end to the bottom caisson 1 is used. Is installed in a winch 3a of a hoist ship 7 via a pulley 3b provided in the installation caisson 2, and a hoist ship in which a winch is also installed (not shown), There can be mentioned various aspects such as a drawing wire rope, one end of which is connected to the installation caisson, can be wound and unwound freely mounted on the winch of the hoist ship through a pulley provided in the bottom caisson, In the case of these modes, the tug 9 is arranged around the installed caisson 2 such as the direction opposite to the bottom caisson 1 and the direction perpendicular to the normal 10 with respect to the installed caisson 2, and the tug 9 and the installed caisson 2 The rope It is connected with. And the operation | work which moves the installation caisson 2 is performed, pulling with this tugboat 9. FIG.
Here, for example, when the buoyancy of the installation caisson 2 is small, the hoist ship 7 in which the crane 8 is installed is used, and the suspension is connected to the upper end of the installation caisson 2 as shown in FIG. Hook the wire rope 8a on the hook of the crane 8 so that the installation caisson 2 is suspended, and place the installation caisson 2 in a predetermined sea area where the installation caisson 2 is to be installed. Work may be performed.
[0005]
Such caisson installation work is performed at sea even if the weather conditions are good, so the floating installation caisson 2 always swings in all directions. Since the installation caissons 2 may collide with the bottom caissons 1 and break each other when they are close to the bottom caissons 1, the side walls 1b of the bottom caissons 1 facing the installation caissons 2 are shown in FIGS. Thus, it was extremely important to dispose the shock absorbing material 5 to loosen the impact and prevent the caissons 1 and 2 from being damaged.
[0006]
Conventionally, as the cushioning material 5 for preventing breakage due to the collision of caisson, square wood (wood), rubber fenders, rubber tires, etc. are used, and the operator uses a hanging means such as a rope to reach the bottom caisson. The cushioning material 5 was suspended from the upper end of the bottomed caisson 1 by gripping it at a predetermined position on the bottom 1.
That is, since the installation caisson 2 is installed at a predetermined interval with respect to the bottoming caisson 1, the cushioning material 5 having a width substantially equal to the predetermined interval is placed at a predetermined position by a hanging means such as a rope. In the state suspended from the upper end of 1, the installation position was precisely positioned, confirmed and corrected, the installation caisson 2 was settled on the foundation rubble 6, and then the cushioning material 5 was pulled up and removed by the operator.
[0007]
However, as described above, the installation caisson 2 is always oscillating in all directions, and the position adjustment of the installation caisson 2 is performed by winding and unwinding the winch. is there. Therefore, if the installation caisson 2 is pulled too close to the bottom caisson 1 by the winch, the buffer material 5 is strongly held between the installation caisson 2 and the bottom caisson 1, and the buffer material 5 cannot be pulled up. It was. In such a case, when the installed caisson 2 installed with high accuracy is drained from the internal water or is suspended by the crane 8, the cushioning material 5 is removed by the caisson moving means after floating slightly by crane operation. It is moved to the side opposite to the bottomed caisson 1 to the extent that it can be removed, and after the buffer material 5 is removed, the water is poured again or the crane operation is performed to make the bottoming. There is a drawback in that the position may be shifted when it is moved, and it takes time to install the installation caisson 2 at a predetermined position again with high accuracy.
[0008]
Further, on the bottom caisson 1, members constituting caisson moving means such as wire ropes, anchor wire ropes, winches, pulleys, pumps and other mechanical devices for pouring or draining seawater into the installation caisson 2 are provided. Since the cushioning material 5 is held by the suspension means on the bottoming caisson 1 as described above, the cushioning material 5 is interposed between the installation caisson 2 and the bottoming caisson 1. When the force of holding the cushioning material 5 is suddenly weakened due to the influence of the swell or the like when the operator is gripping and holding the suspension means firmly, the reaction force balances the operator. There is a drawback that it is very dangerous to fall and fall into the sea between the installed caisson 2 and the bottomed caisson 1 stumbling on a troublesome mechanical device.
[0009]
[Problems to be solved by the invention]
The present invention eliminates the drawbacks of the prior art described above, and performs the work of bottoming a caisson that is next installed at a predetermined interval adjacent to an existing caisson that is grounded on a foundation rubble on the seabed. It is an object of the present invention to provide a caisson installation method at sea that can be performed safely and in a short time.
[0010]
[Means for Solving the Problems]
As a result of intensive studies to solve such problems, the present inventors have installed a caisson on the sea in the vicinity of the bottoming caisson that has been bottomed on a foundation rubble spread on the bottom of the sea. A bottoming caisson and an installation caisson are used to move the installation caisson when moving to a position spaced apart from the bottoming caisson after being positioned away from the foundation rubbing stone and landing on the foundation rubbing stone. The caisson moving means installed at the bottom is operable, and the internal pressure is adjusted by the pressure adjusting means and the pressure adjusting means so that the caisson is wider than a predetermined interval at which the installation caisson is installed from the bottom caisson. Two or more of the air bags of the shock absorber provided with the air bag formed with the contact portion are suspended from the upper surface of the bottomed caisson to the side wall facing the installation caisson at an interval. From the state in which the inside is made high pressure, the installation caisson is allowed to settle until the bottom part is located in the vicinity of the foundation rubble, and the caisson moving means draws the installation caisson to the bottom caisson side to contact the air bag of the shock absorber. After adjusting the position of the installation caisson by the caisson moving means while adjusting the pressure in the air bag, the installation caisson is allowed to settle until the bottom of the installation caisson is placed on the foundation rubble and settled down. Later, if the pressure inside the air bag is reduced by the pressure adjusting means and then the air bag is contracted and then pulled up, the installation caisson to be installed next is installed at a position spaced a predetermined distance from the bottom caisson. The present invention was completed by investigating that it can be performed safely and quickly.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a method for installing a caisson on the sea according to the present invention will be described in detail 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. (A) is a side view, (b) is a plan view, and FIG. 4 shows a process in which the method of the present invention is being carried out. The caisson and the bottom caisson are in a state where the caisson moving means can be operated and the air bag of the shock absorber is suspended from the top of the bottom caisson. FIG. 5 and FIG. 5 show the process of carrying out the method of the present invention. The caisson moving means moves the installation caisson to the bottom caisson side and shows the position (a) is an explanatory side view. (B) is an explanatory plan view.
[0012]
In the drawings, 1 is a bottoming caisson in which a bottom portion 1a is previously grounded on a foundation rubble 6 spread on the seabed, and 2 is a bottoming caisson adjacent to the bottoming caisson 1 at a predetermined interval. Like the caisson 1, the caisson is a stationary caisson that is placed on the foundation rubble 6 with the bottom 2a placed on the bottom. These bottoming caisson 1 and installation caisson 2 are made of concrete or steel plate, and as shown in FIG. 2, at least opposing side walls 1b and 2b are formed flat and are surrounded by side walls 1b and 2b. Bulkheads 1c and 2c are formed over the entire height, and the bottoms 1a and 2a are closed.
[0013]
3 indicates that the base 2a is moved away from the foundation rubble 6 and the installation caisson 2 is moved to the bottom caisson 1 side so that the side surface of the bottom caisson 1 and the side surface thereof are aligned. The caisson moving means for correcting the position in the direction of 10 and the caisson moving means described as the prior art can be used, and the description thereof is omitted.
[0014]
Reference numeral 4 denotes a shock absorber provided with a pressure adjusting means 4a and an air bag 4b formed of a soft material that is supplied and discharged by the pressure adjusting means 4a to increase / decrease the volume and expand / contract. . The air bag 4b has a caisson abutting portion 4bc wider than a predetermined interval at which the installation caisson 2 is installed from the bottomed caisson 1 in a state where air is supplied and the inside thereof is expanded to a high pressure. Further, a rope 4bd is attached to the air bag 4b in order to hang the air bag 4b from the bottomed caisson 1 and lift the air bag 4b after the bottomed caisson 1 is bottomed.
[0015]
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, it is about 1,000 tons. Therefore, it can be used if it has a strength that can be withstood when pressed by the bottoming caisson 1 and the installation caisson 2 and the volume can be increased or decreased. Further, the air bag 4b is used by being suspended near the sea surface and lifted up by the operator after the installation caisson 2 is settled at a predetermined position, so that the weight of the air bag 4b increases when the material absorbs water. Since the burden on the worker is sometimes increased, it is preferable that water is not absorbed. In consideration of these, it is preferable that the air bag 4b is formed of various rubbers and the like. As shown in FIG. 1, the air bag 4b is a rubber reinforcement in which a reinforcing material such as a nylon cord is embedded in a rubber body 4ba. An example is one in which the band 4bb is provided around the vertical direction and the horizontal direction at intervals.
[0016]
Further, the caisson contact portion 4bc of the air bag 4b is fixed with a member for reducing the frictional resistance generated when the surface and the caisson come into contact with each other, for example, a plate made of fluororesin. It is preferable that a coating mixed with molybdenum powder is applied because the air bag 4b can be prevented from being damaged.
[0017]
The pressure adjusting means 4a includes a compressor 4aa, an air supply flexible tube 4ab having one end connected to the compressor 4aa and the other end connected to the air bag 4b, and a pressure gauge 4ac for detecting the pressure in the air bag 4b. In addition, a configuration including a valve 4ad for exhausting air in the air bag 4b can be given.
[0018]
In order to carry out the method of the present invention and place the installation caisson 2 in a predetermined position on the foundation rubble 6 adjacent to the bottom caisson 2, the installation caisson 2 is first placed in a predetermined position. In other words, the installation caisson 2 is positioned in the vicinity of the bottom caisson 1 where the installation caisson 2 has been already installed and next to the installation caisson 2 with the bottom 2a away from the foundation rubble 6, and the caisson is placed. The installed caisson 2 to be installed from the temporary caisson storage site is towed to the predetermined position by a tug in a suspended state, or the hoisting ship 7 in which the crane 8 is installed is used to suspend the wire. The hoist ship 7 is sailed while being suspended via the rope 8a and carried to the predetermined position.
[0019]
Then, the pressure adjusting means 4a is installed on the bottoming caisson 1, and the air bag 4b is set to a high pressure inside the air bag 4b by the pressure adjusting means 4a so that the caisson contact part 4bc is formed from above the bottoming caisson 1. Two or more shock absorbers 4 are installed on the bottom caisson 1 with two or more suspended from the side wall 1b opposed to the two. The air bag 4b may be suspended by fixing a hanging metal fitting to the bottom caisson 1 and fixing the rope 4bd attached to the air bag 4b to the hanging metal fitting.
In addition, caisson moving means 3 for moving the installation caisson 2 positioned near the bottom caisson 1 and having the bottom 2a separated from the rubble 6 is installed.
[0020]
Subsequently, 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 is used to move the installation caisson 2 to the bottom caisson 1 side. At this time, when towing the installation caisson 2 as described above, since 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, the installation caisson 2 When the primary water is poured into the space surrounded by the side wall 2b and is suspended by the crane 8, the crane 8 is operated and the bottom portion 2a is located near the foundation rubble 6 but has not yet settled. Settling to the state of being. The operation of sinking or floating the installation caisson 2 in this way is performed by pouring / draining water into the installation caisson or operating the crane 8 and may be simply referred to as sedimentation or floating below. .
[0021]
Then, the installation caisson 2 and the bottom caisson 1 are held at an interval wider than the predetermined interval in a state where the installation caisson 2 is drawn toward the bottom caisson 1 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 corrected by the caisson moving means 3, and the pressure in the air bag 4b is adjusted so that the distance from the bottom caisson 1 of the installation caisson 2 is a predetermined interval. The installation caisson 2 is moved and corrected by the caisson moving means 3 while being adjusted by the pressure adjusting means 4a. At this time, the installation caisson 2 is attracted by the caisson moving means 3 to the bottom caisson 1 side with a certain force.
[0022]
After that, when the bottom 2a of the installation caisson 2 is placed on the foundation rubble 6 and settled until it is settled, the installation of the installation caisson 2 is completed, and the pressure in the air bag 4b is lowered by the pressure adjusting means 4a. If the air bag 4b is contracted and then lifted, the entire operation is completed.
[0023]
【The invention's effect】
When such a method of the present invention is carried out and the installation caisson 2 is installed at a position spaced by a predetermined interval adjacent to the bottoming caisson 1 already bottomed on the foundation rubble 6, When the installation caisson 2 positioned in the vicinity of the bottom caisson 1 and floating is moved to the bottom caisson 1 side, the installation caisson 2 is swung in all directions under the influence of waves, and the bottom caisson 1 The air bag 4b of the shock absorber 4 is suspended from the side wall 1b facing the installation caisson 2 of the bottomed caisson 1, so that the installation caisson 2 collides with the bottomed caisson 1. Can be installed without damaging the very expensive caisson.
[0024]
In addition, the air bag 4b of the shock absorber 4 has a caisson contact portion 4bc wider than a predetermined interval at which the installation caisson 2 is installed from the bottom caisson 1 when air is supplied and inflated. 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 4 b of the shock absorber 4. By opening the valve 4ad of the pressure adjusting means 4a and discharging the air in the air bag 4b to lower the pressure, the volume in the air bag 4b is reduced and the distance between the installation caisson 2 and the bottomed caisson 1 is reduced. Can be modified as follows. That is, since two or more air bags 4b of the shock absorber 4 are hung at intervals, when the installation caisson 2 is in contact with the air bag 4b at an angle shifted from the normal line 10, The distance between the installation caisson 2 and the bottom caisson 1 is adjusted by reducing the pressure in the air bag 4b on the side (the side where the distance between the bottom caisson 1 and the installation caisson 2 is wide) as described above, and the angle Can be corrected.
[0025]
Further, since the air bag 4b of the shock absorber 4 is formed of a soft material, the bottom caisson 1 is grounded on the basic rubble 6 by discharging the air in the air bag 4b and reducing the pressure. After that, the air bag 4b can be easily pulled up from the gap between the bottoming caisson 1 and the installation caisson 2. Therefore, the air bag 4b of the shock absorber 4 can be used repeatedly, which is economical. If the caisson contact portion 4bc of the air bag 4b of the shock absorber 4 is provided with a member that reduces the frictional resistance, the air bag 4b can be prevented from being damaged and the life of the air bag 4b can be extended. Can be more economical.
[0026]
The air bag 4b of the shock absorber 4 need only be hung from the hanging metal fitting on the bottom caisson 1 with a rope, and need not be supported by the operator, and pressure adjusting means for adjusting the pressure in the air bag 4b Since the operation of 4a can be performed from this position by installing pressure adjusting means 4a at a position away from the side wall, an operator may fall on the sea between the bottom caisson 1 and the installation caisson 2. There is no safety.
[0027]
Thus, the caisson installation method on the sea according to the present invention that exhibits various effects as described above has a very large industrial value.
[Brief description of the drawings]
FIG. 1 is a front 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 basic rubble, (A) is a side explanatory view, and (B) is a plane explanatory view.
FIG. 4 shows a process in which the method of the present invention is carried out, and the caisson moving means is made operable in the installed caisson and the bottomed caisson floating in the vicinity of the bottomed caisson and the air bag of the shock absorber is installed. FIG. 2A is a side explanatory view and FIG. 2B is a plane explanatory view showing a state of being hung from the upper part of the bottom caisson.
FIG. 5 shows a process in which the method of the present invention is carried out, and shows a state in which the installation caisson is moved to the bottom caisson side by the caisson moving means and positioning is performed (a) is an explanatory side view; (B) is an explanatory plan view.
FIG. 6 is a flow sheet for explaining a series of operations for installing the installation caisson to be installed next to the bottoming caisson at a predetermined interval.
FIG. 7 is an explanatory side view showing a state in which installation work is performed using a conventional cushioning material while preventing direct contact between the installation caisson and the bottom caisson.
FIG. 8 is an explanatory plan view showing caisson moving means.
FIG. 9 is an explanatory front view showing a state in which an installation caisson is suspended by a crane installed in a hoist ship.
[Explanation of symbols]
1 Bottoming 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 Lead wire rope
3d anchor wire rope 4 shock absorber
4a Pressure adjusting means
4aa compressor
4ab air supply flexible tube
4ac pressure gauge
4ad valve
4b air bag
4ba body
4bb reinforcement band
4bc Caisson contact part
4bd rope 5 cushioning material 6 foundation rubble 7 hoist ship 8 crane
8a Hanging wire rope 9
10 Normal

Claims (3)

On the foundation rubble (6) spread on the sea floor, the bottom (1a) is placed in advance near the bottom caisson (1). ) Is moved away from the bottom caisson (1) and moved to a position spaced a predetermined distance from the bottom caisson (1) to move the installation caisson (2) on the foundation rubble (6). To make the caisson moving means (3) installed in the bottom caisson (1) and the installation caisson (2) operable, the pressure adjusting means (4a) and the pressure adjusting means (4a) A shock absorber provided with an air bag (4b) having a caisson contact portion (4bc) wider than a predetermined interval at which the internal pressure is adjusted and the installation caisson (2) is installed from the bottom caisson (1). 4) The air bag (4b) of 2) is spaced from the upper surface of the bottomed caisson (1) to the side wall (1b) facing the installation caisson (2). The installation caisson (2) is submerged until the bottom (2a) is located in the vicinity of the foundation rubble (6) and the installation caisson (2) is moved by the caisson moving means (3). The position of the installation caisson (2) is adjusted while adjusting the pressure in the air bag (4b) from the state where it is drawn to the bottom caisson (1) and brought into contact with the air bag (4b) of the shock absorber (4). After the movement is corrected by the moving means (3), the installation caisson (2) is allowed to settle until the bottom (2a) of the installation caisson (2) is placed on the foundation rubble (6) and then settled. A caisson installation method at sea, wherein the pressure inside the air bag (4b) is lowered by the pressure adjusting means (4a) and then the air bag (4b) is contracted and then pulled up. The method for installing a caisson on the sea according to claim 1, wherein the air bag (4b) is a rubber body (4ba) having a reinforcing band (4bb) around the peripheral surface thereof. The method for installing caisson at sea according to claim 1 or 2, wherein the air bag (4b) is provided with a member for reducing frictional resistance generated between the caisson abutting portion (4bc) and the caisson. .

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