JP4676621B2 - Method for correcting uneven settlement of soft-floating floating structures - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention avoids vertical movement caused by fluctuations in tide level and reduces the consolidation settlement of the bottom of the ground by lightly landing a floating structure placed on the surface of the water with fluctuations in the tide level. The present invention relates to a method for correcting uneven settlement of a bottom floating structure.
[0002]
[Prior art]
The soft-floating type floating structure receives buoyancy and settles on the bottom ground with a slight load, so there is an advantage that the settlement of the bottom bottom due to the load of the structure can be reduced, and the pontoon There are advantages such as avoiding up and down movement due to tide level fluctuations as seen in floating structures of the system, and there is no fluctuation due to waves and winds, but because it is always settled on the bottom of the water, there is uneven settlement on the bottom of the water. When this occurs, the soft bottom floating structure will incline following it, and the level of the soft bottom floating structure needs to be corrected.
[0003]
In the case of the uneven settlement of a soft-floating floating structure that follows the uneven settlement of such submerged ground, a jack-type level that has conventionally been installed directly below the first floor of a building constructed on the soft-floating floating structure. It was thought that it would be sufficient to correct at the floor level by jacking up the building with an adjustment mechanism.
[0004]
However, with this modified method, for example, when a large consolidation subsidence has occurred even in a diluvium that was considered to be negligible under the alluvial clay layer where consolidation settlement is expected. In addition, when the actual subsidence amount is larger than the expected subsidence amount, there is a problem that the jack-up stroke is insufficient, and the jack replacement work is required. This replacement work is a large-scale construction and the construction cost is enormous.
[0005]
In addition, in the soft bottom floating structure described in Japanese Patent Publication No. 2-20768, a plurality of column bases that support a deck portion located above the water surface are constituted by an inner column and an outer column, The inside of the outer column is formed in a buoyancy tank chamber that can adjust the buoyancy, and the bottom end of each column base is configured to softly settle on the water bottom ground, while the inner column of each column base is inserted into the deck portion Provided with a plurality of hollow struts, and a position adjusting device composed of a vertical rack provided on the inner pillar side and a worm provided on the pillar side between the pillar and the inner pillar, respectively. By adjusting the vertical position of the inner column with respect to the pillar, in other words, the vertical position of the deck portion with respect to the column base, the deck portion is configured to be kept horizontal. Therefore, when the actual settlement amount is larger than the expected settlement amount, it is necessary to extend the rack by adding the inner pillar, which is not a big difference from the jack replacement work in that it is a large construction. Further, the added inner pillar protrudes from the upper surface of the deck portion, which becomes an obstacle when using the deck portion, and there is a problem that the use of the deck portion is limited.
[0006]
[Problems to be solved by the invention]
The present invention has been made in consideration of the above points, and the object of the present invention is to follow the non-settlement of the submerged ground and the non-settlement of the soft-floating floating structure occurs. Using the buoyancy adjustment mechanism (ballast water pouring / draining mechanism) that is naturally installed in the bottom floating structure, the soft-floating floating structure is once lifted, and in this state, the surface of the water bottom ground is leveled horizontally. After that, by re-floating the soft bottom floating structure, even if the subsidence of the water bottom ground where the soft bottom floating structure bottoms is large, the refilling work of the jack that corrects at the floor level is performed. It is an object of the present invention to provide a method for correcting the uneven settlement of a soft bottom floating structure that can be handled without performing it.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the technical means taken by the present invention are as follows. That is, the method for correcting the uneven settlement of a soft-floating floating body structure according to the first aspect of the present invention is based on the fact that the floating structure placed on the water surface with fluctuations in the tide level is lightly settled on the water bottom ground, thereby In a floating structure with a soft bottom that avoids movement and reduces consolidation settlement of the bottom of the ground, when a certain amount of non-uniform settlement occurs in the bottom of the ground where the floating structure settles, the floating structure The floating structure is floated by discharging the ballast water of the object, and after leveling the surface of the bottom bottom ground by inserting a leveling device into the gap formed between the floating structure and the bottom bottom ground, the ballast is applied to the floating structure. It is characterized in that the floating structure is softly settled on the water bottom ground by reinjecting water.
[0008]
According to the above configuration, when uneven settlement occurs in the water bottom ground, the floating structure that is softly settled on the water bottom ground is also inclined to follow, but on the necessity of softly grounding the floating structure, Naturally, by using the buoyancy adjustment mechanism (ballast water pouring / draining mechanism) that is equipped, the ballast water of the floating structure is discharged to make the floating structure lighter than the weight required for the soft bottom. Can be floated on water.
[0009]
And due to the floating of the floating structure, a gap corresponding to the inclination of the bottom of the ground is generated between the floating structure and the bottom of the ground, so a leveling device is inserted into this gap to level the surface of the bottom of the ground, The surface of the bottom structure is corrected horizontally, and then the ballast water is reinjected into the floating structure to increase the weight of the floating structure to the weight required for the soft bottom, and the floating structure is designed as a bottom structure. The bottom is softly ground so that the load becomes the street.
[0010]
Accordingly, the stroke of the jack for correcting at the floor level above the floating structure can be shortened, and even if the subsidence of the submarine ground is large, it is possible to cope without performing the jack replacement work.
[0011]
In particular, since the water bottom ground is leveled and leveled, no leveling filler is required, which is economical. In addition, it is possible to sink the floating structure by excavating the water bottom ground with a leveling device, so a soft-floating floating structure is installed in the water area between landfills where large consolidation settlement is expected. In this case, compared to the bottom ground where the floating structure touches down, even if land reclamation on both sides progresses, the floating structure will sink by excavating the bottom ground, and the slope of the bridge connecting to the landfill will be increased. Can be relaxed.
[0012]
The method for correcting the uneven settlement of the soft bottom floating structure according to the invention according to claim 2 is to connect the floating part having a large horizontal area always below the water surface and the deck part always above the water surface. A semi-latent soft bottom floating structure with a floor slab provided on the deck portion via a level adjustment mechanism, and a bottom ground on which the floating structure bottoms. When a certain amount of uneven subsidence occurs, the floating structure is floated by discharging the ballast water of the floating structure, and a leveling device is inserted into the gap formed between the floating structure and the bottom ground. After the surface is leveled, ballast water is reinjected into the floating structure to softly settle the floating structure on the bottom of the ground.
[0013]
According to this configuration, in addition to the same advantages as those of the invention described in claim 1, since the volume change of the portion located in the water when the tide level fluctuates is small, the fluctuation in buoyancy due to the tide level fluctuation can be kept small. There is an advantage that you can.
[0014]
It should be noted that the present invention can be applied to a single soft-bottom floating structure, but as described in claim 3, a plurality of floating structures can be moved around each other and moved around the horizontal axis. It can be applied to a large-scale artificial ground having a soft-floating floating structure by connecting the floor slabs in an integrated manner in a loose state that allows the rotation of the floor. In other words, each floating structure follows the subsidence of the submarine ground.For the subsidence within the expected range, the floor slab is corrected by the level adjustment mechanism, and the subsidence is larger than expected. Can cope with this by leveling the surface of the bottom ground where the floating structure contacts the ground, and even if the adjustment stroke by the level adjustment mechanism is short, the level adjustment mechanism need not be replaced.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
(A) to (b) in FIG. 1 show, for example, changes in tide level such as the sea level left between the landfill or the landfill 1a created at an old time and the new landfill 1b built nearby. A large-scale artificial ground having a semi-latent soft bottom floating structure arranged on a certain water surface 2 is shown. This artificial ground is constructed by connecting a plurality of unitized floating structures A.
[0016]
Each floating structure A employs a soft bottoming system in which the bottom bottom ground B is lightly grounded to avoid vertical movement due to tide level fluctuations and to reduce the consolidation settlement of the bottom bottom ground B. Thus, a floating body portion 3 having a large horizontal area that is always located below the water surface 2, a deck portion 4 that is always located above the water surface 2, and a column portion 5 of a steel truss structure having a small horizontal area that connects the three and four. It is a so-called semi-latent floating structure composed of the following, and is designed to minimize fluctuations in buoyancy caused by fluctuations in tide level.
[0017]
The deck portion 4 is provided with a floor slab 7 capable of constructing a building in an upper portion thereof supported by a number of level adjusting mechanisms 6 using jacks or the like. These level adjusting mechanisms 6 are for dealing with the uneven subsidence of the artificial ground that follows the small subsidence of the expected range of the water bottom ground B, and are adapted to correct at the floor level.
[0018]
As shown in FIG. 1 (a), for example, the adjacent floating structure A is made up of a vertical movement and a horizontal axis by means of ring-shaped connecting hardware 8a, 8b, etc., which are loosely engaged with each other. It is connected in a loose state that allows rotation around the core, and only the floor slabs 7 are integrally connected to each other by, for example, spotting concrete.
[0019]
The floating body portion 3 is formed in a box shape, the interior is partitioned into a plurality of chambers, and ballast water (seawater) a is stored in each chamber as shown in (a) to (e) of FIG. ing. And by adjusting the amount of ballast water (seawater) a stored in each room by a buoyancy adjustment mechanism (ballast water pouring / draining mechanism) 9 composed of a submersible pump 9a and a ballast pouring / draining pipe 9b, The buoyancy (contact pressure to the water bottom ground B) can be adjusted.
[0020]
Reference numeral 10 shown in FIGS. 2A to 2B is a leveling device that can be inserted between the floating body portion 3 of the floating structure A and the bottom ground B, and in the state where the floating structure A is floated, The ground B can be leveled.
[0021]
The leveling device 10 can be embodied by various configurations. For example, as shown in FIGS. 2A to 2B, the leveling device 10 is protruded downward from the first posture in which the leveling device 10 is stored in a storage chamber formed in a part of the floating body portion 3 and the bottom surface of the floating body portion 3. In the state where the leveling device 10 is switched to the second posture, by horizontally moving along the guide rail 11 provided on the bottom surface of the floating body portion 3, It may be in a form that is leveled horizontally, and is composed of an unmanned underwater bulldozer that can be remotely operated, as shown in FIGS. 3 (a) to 3 (d). The leveling device 10 may be used. In the illustrated example, the buoyancy adjustment mechanism 9 is configured using the submersible pump 9a. However, in order to improve maintainability, a buoyancy adjustment mechanism using a normal pump installed in the deck portion 4 or the column portion 5 is used. 9 may be configured.
[0022]
According to the above configuration, when the uneven subsidence occurs in the water bottom ground B, the floating structure A is inclined following this. However, when the subsidence of the submarine ground B is small, the floating structure A has a slight inclination. Therefore, for the subsidence of the artificial ground following the subsidence, the floor slab of the part necessary for the level adjustment mechanism 6 is used. This can be dealt with by raising 7 to the column part 5 by the required amount.
[0023]
If large subsidence that cannot be dealt with by the level adjustment mechanism 6 alone occurs in the bottom of the ground B, the correction is made by the methods shown in FIGS. 2 (a) to (b) and FIGS. 3 (a) to (d). Do it. That is, a large uneven subsidence occurs in the bottom of the ground B, and the floating body portion 3 of the floating structure A is greatly inclined as shown in FIGS. 1 (B), 2 (A), and 3 (A). In this case, as shown in FIG. 2B and FIG. 3B, the floating body structure A is floated by discharging the ballast water a contained in the floating body portion 3 of each floating body structure A. A gap S is formed between the floating body portion 3 of the floating structure A and the water bottom ground B.
[0024]
In this state, as shown in FIG. 2C, the leveling device 10 provided in the floating body portion 3 is switched to the second posture and inserted into the gap S, or as shown in FIG. Thus, the ground leveling device 10 separate from the floating body portion 3 is lowered into the water, inserted into the gap S, and the leveling device 10 is moved in the horizontal direction, so that (d) in FIG. As shown in c), the inclined water bottom ground B is leveled horizontally.
[0025]
When the leveling of the submarine ground B is completed, the leveling device 10 is returned to the original position, and the buoyancy adjusting mechanism is once again as shown in (c) of FIG. 1, (e) of FIG. 2, (d) of FIG. 9, the ballast water a is reinjected into the floating body portion 3 to increase the weight of the floating body structure A, and the floating body portion 3 of the floating body structure A is made flat on the water bottom ground B. The bottom is soft.
[0026]
As described above, since the uneven settlement of the soft-floating floating structure A is corrected by leveling the slope of the water bottom ground surface B to which the floating structure A contacts the ground, the correction at the level of the floor slab 7 is performed. Even if the adjustment stroke of the level adjustment mechanism 6 is short and the subsidence of the water bottom ground B is large, the level adjustment mechanism 6 can be dealt with without performing a replacement work.
[0027]
In particular, since the water bottom ground B is leveled and leveled, a leveling filler is unnecessary and economical. Further, since the floating structure A can be subsidized by excavating the water bottom ground B with the leveling device 10, as shown in FIG. 1, between the landfills 1a and 1b where a large consolidation subsidence is expected. When the soft bottom floating structure A is installed in the water area, even if the settlement of the landfills 1a and 1b on both sides progresses as compared to the water bottom ground B where the floating structure A contacts the ground, the bottom ground B The slope of the connecting bridge 12 with the landfills 1a and 1b can be relaxed by sinking the floating structure A by excavation of.
[0028]
【The invention's effect】
Since the present invention has the above-described configuration, when the subsidence of the soft bottom floating structure occurs following the subsidence of the submarine ground, the buoyancy adjustment mechanism (equipped naturally in the soft bottom floating structure) ( Using a ballast water pouring and draining mechanism), the soft-floating floating structure is temporarily levitated, and in this state, the surface of the water-floor ground is leveled, and then the soft-floating floating structure is soft-floated. This makes it possible to correct the soft-floating floating structure horizontally, and even if the subsidence of the water-floor ground where the soft-floating floating structure bottoms is large, the refilling work of the jack that corrects at the floor level There is an effect such as being able to cope without performing.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an artificial ground illustrating an application target of a method for correcting uneven settlement of a soft-floating floating structure according to the present invention.
FIG. 2 is an explanatory diagram of a method for correcting uneven settlement of a soft bottom floating structure according to the present invention.
FIG. 3 is an explanatory diagram of a method for correcting uneven settlement of a soft bottom floating structure showing another embodiment.
[Explanation of symbols]
A ... soft bottom floating structure, B ... water bottom ground, a ... ballast water, b ... filler, 10 ... leveling device.

Claims (3)

A floating structure that floats on the surface of the water with fluctuations in the tide level is lightly settled on the bottom surface of the ground, thereby avoiding vertical movement due to fluctuations in the tide level and reducing the settlement of the bottom surface of the ground. In the structure, when the subsidence beyond a certain level occurs in the bottom ground where the floating structure reaches the bottom, the floating structure is floated by discharging the ballast water of the floating structure, and the floating structure and the bottom ground It is characterized by softening the floating structure to the bottom ground by inserting a leveling device into the gap formed between them and leveling the surface of the bottom, and then reinjecting the ballast water into the floating structure. To correct uneven settlement of floating bottom floating structure. It consists of a floating part with a large horizontal area that is always located below the water surface, a deck part that is always located above the water surface, and a column part with a small horizontal area that connects the two parts. In a semi-latent soft bottom floating structure with a floor slab, the ballast water of the floating structure is discharged when a certain amount of uneven subsidence occurs in the water bottom ground where the floating structure bottoms. After floating the floating structure by inserting a leveling device in the gap formed between the floating structure and the bottom of the ground and leveling the surface of the bottom, the ballast water is reinjected into the floating structure, A method of correcting uneven settlement of a soft bottom floating structure characterized by softly bottoming a floating structure on a water bottom ground. The plurality of floating structures are connected in a loose state that allows mutual vertical movement and rotation around a horizontal axis, and floor slabs are integrally connected. A method for correcting uneven settlement of floating bottom floating structures.

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