Buoyancy blocks for artificial islands and construction method for artificial islands using these buoyancy blocks

Abstract

This invention provides buoyancy blocks for artificial islands that minimize the subsidence of artificial islands and the ground supporting them, as well as a construction method for artificial islands using these buoyancy blocks. [Solution] A floating structure 2 is formed by arranging multiple artificial islands 1 in appropriate locations, and the artificial island buoyancy block 3 is equipped with a buoyancy material 6 that generates buoyancy. The artificial island buoyancy block 3 comprises a concrete hollow block 4 with a hollow section 5 formed inside the block body which is made up of a hexahedron, and a buoyancy material 6 which is installed in the hollow section 5 of the hollow block 4 and has a specific gravity less than that of water. The volume of the hollow section 5 of the hollow block 4 is 60% or more of the total volume, and the volume of the buoyancy material 6 provided in the hollow section 5 is 60% or more.

Description

Technical Field

[0001] The present invention relates to a buoyancy block used for artificial islands installed by reclaiming seas, lakes, rivers, etc., and a method for constructing an artificial island using this buoyancy block.

Background Art

[0002] Conventionally, when building large facilities such as airports and power plants, a vast amount of land is required, but it has become extremely difficult to find suitable sites on land. For example, in the case of an airport, there are problems such as opposition movements by neighboring residents due to noise problems, and it is impossible to acquire privately-owned land inside and outside the airport site from landowners.

[0003] Also, in the case of a solar power plant, there are problems such as opposition movements by neighboring residents due to reflected light problems, and it is impossible to acquire flat land for placing many solar cells.

[0004] Furthermore, in the case of a thermal power plant, a large amount of water is required to cool the steam after rotating the steam turbine and return it to water, and in the case of a nuclear power plant, a large amount of water is required for reactor cooling, so it must be installed near the sea, and there is a problem that countermeasures against large waves such as building dikes over a wide area are necessary.

[0005] In recent years, as a countermeasure to such land acquisition problems, artificial islands represented by megafloats (giant artificial floating islands) installed by reclaiming seas, lakes, rivers, etc. have attracted attention. On the other hand, in recent years, it has become known that in coastal areas, etc., there is a soft layer containing many water pools and cavities at a depth of 70 m to 90 m underground, and a construction method that combines safety and economy is urgently desired. Although the sand compaction method is widespread as a countermeasure against settlement of soft ground, the implementation of this method at a large depth underground (50 m or more) is economically and in terms of construction period difficult.

[0006] As an example of this type of artificial island, Patent Document 1 discloses a method for creating an artificial island characterized by improving the soft ground of the seabed along the outline of the artificial island to an appropriate width, constructing a seawall on top of the improved ground, and then filling the reclaimed area enclosed by the seawall with a reclamation material made by mixing cohesive soil with water, a cement-based solidifying agent, a foaming agent, and a separation reducing agent, using underwater construction. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 4-149308 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Artificial islands like the one described in Patent Document 1 have a problem in that if there is a soft layer in the subsurface layer of the seabed ground that forms the foundation of the ground improvement section and the reclaimed area, the artificial island and the ground will subside due to the weight of the artificial island itself.

[0009] This invention has been made in view of the above problems, and aims to provide a buoyancy block for artificial islands that prevents the subsidence of artificial islands and the ground supporting them as much as possible, and a method for constructing artificial islands using this buoyancy block. [Means for solving the problem]

[0010] The buoyancy block for an artificial island according to claim 1 of the present invention constitutes a floating structure by arranging a plurality of such blocks in appropriate locations on an artificial island, and is equipped with a buoyancy material that generates buoyancy,

[0011] The invention is characterized by comprising a concrete hollow block having a hollow section formed inside a block body consisting of a hexahedron, and a buoyancy material having a specific gravity less than that of water, which is installed in the hollow section of the hollow block, wherein the volume of the hollow section of the hollow block is 60% or more of the total volume, and the volume of the buoyancy material installed in the hollow section is 60% or more.

[0012] The buoyancy block for an artificial island according to claim 2 of the present invention is characterized in that, according to claim 1, the buoyancy material is one or more types of foamed resins such as expanded polystyrene (EPS), expanded polyethylene (EPE), and expanded polypropylene (EPP), pumice, and foamed beads which are closed-cell foams.

[0013] The buoyancy block for an artificial island according to claim 3 of the present invention is characterized in that, in claim 1, the concrete block body of the hollow block is provided with reinforcing bars on each side of the hexahedron.

[0014] The method for constructing an artificial island using buoyancy blocks according to claim 4 of the present invention is a method for constructing an artificial island using buoyancy blocks that are equipped with a buoyancy material that generates buoyancy, wherein a floating structure is formed by arranging a plurality of buoyancy blocks in appropriate locations on the artificial island,

[0015] A buoyancy block consists of a hollow concrete block with a hollow section formed inside a block body made of six hexahedrons, and a buoyancy material with a specific gravity lower than water that is placed inside this hollow section of the block.

[0016] In order to separate the installation site for the artificial island from the surrounding water, an embankment wall is constructed with its upper end positioned above the surrounding water level, and reclaimed soil is brought into the area enclosed by this embankment wall to create an artificial ground with a predetermined bearing capacity.

[0017] The floating structure consists of a concrete base plate installed on the artificial ground and a plurality of buoyancy blocks installed on this base plate.

[0018] The artificial ground is leveled, then the base slab is installed, multiple buoyancy blocks are laid across the entire upper surface of the base slab so that their upper surfaces are above the surrounding water level, and a concrete roadbed is installed on top of the buoyancy blocks.

[0019] The method for constructing an artificial island using buoyancy blocks according to claim 5 of the present invention is characterized in that, according to claim 4, the artificial ground is formed to have a predetermined bearing capacity by a sand compaction method after bringing in and leveling reclaimed soil.

[0020] The method for constructing an artificial island using buoyancy blocks according to claim 6 of the present invention is characterized in that, in claim 4, the bearing capacity of the artificial ground is set to be greater than or equal to the weight of the artificial island, and the buoyancy of the floating structure is set to be less than or equal to the weight of the artificial island. [Effects of the Invention]

[0021] The buoyancy block for an artificial island according to claim 1 of the present invention is a buoyancy block for an artificial island that constitutes a floating structure by arranging multiple blocks in appropriate locations on an artificial island and is equipped with a buoyancy material that generates buoyancy, comprising a concrete hollow block with a hollow section formed inside a block body consisting of a hexahedron, and a buoyancy material having a specific gravity less than that of water installed in the hollow section of the hollow block, wherein the volume of the hollow section of the hollow block is 60% or more of the total volume, and the volume of the buoyancy material provided in the hollow section is 60% or more, thereby providing a buoyancy block with sufficient buoyancy.

[0022] By appropriately placing multiple buoyancy blocks with suitable buoyancy on the floating structure of an artificial island, the sinking of the artificial island can be prevented as much as possible.

[0023] The buoyancy block for an artificial island according to claim 2 of the present invention is a buoyancy block that has sufficient buoyancy when the buoyancy material is installed in combination of one or more types from foamed resins such as expanded polystyrene (EPS), expanded polyethylene (EPE), and expanded polypropylene (EPP), pumice, and closed-cell foam beads.

[0024] In addition, these buoyancy materials are installed after the production of the concrete hollow blocks and then transported to the construction site. However, the buoyancy materials may be installed after transporting the hollow blocks to the artificial island construction site, or the buoyancy materials may be installed after manufacturing the hollow blocks themselves at the artificial island construction site. Since it is possible to flexibly respond to the situation at the construction site in this way, the workability of artificial island construction can be improved.

[0025] Particularly, when manufacturing concrete hollow blocks at the artificial island construction site and installing buoyancy materials to manufacture buoyancy blocks, the constraints on transportation are eliminated, resulting in savings in transportation costs. Furthermore, it becomes possible to manufacture large buoyancy blocks using larger hollow blocks, thus saving the labor of manufacturing and construction. As a result, it is possible to reduce the cost of the construction project.

[0026] The buoyancy block for an artificial island according to claim 3 of the present invention, in claim 1, since reinforcing bars are provided on each side of the hexahedron of the concrete block body of the hollow block, it is possible to prevent damage during the transportation of the hollow block or the buoyancy block as much as possible.

[0027] The construction method of an artificial island using the buoyancy block according to claim 4 of the present invention is a construction method of an artificial island using a buoyancy block provided with a buoyancy material that generates buoyancy, by arranging a plurality of them in appropriate positions of the artificial island to form a floating structure.

[0028] The buoyancy block is composed of a concrete hollow block having a hollow portion formed inside a block body composed of a hexahedron, and a buoyancy material installed in the hollow portion of the hollow block and having a specific gravity smaller than that of water, so as to become a buoyancy block having sufficient buoyancy.

[0029] In addition, in order to partition the installation location where the artificial island is installed from the surrounding water, an embankment wall whose upper end is located above the surrounding water surface and fill sand is carried into the inside surrounded by this embankment wall to provide an artificial ground having a predetermined ground bearing capacity.

[0030] The floating structure consists of a concrete base plate installed on the artificial ground and multiple buoyancy blocks installed on the base plate. After ground improvement work is carried out on the artificial ground, the base plate is installed, multiple buoyancy blocks are laid across the entire upper surface of the base plate so that their upper surfaces are above the surrounding water level, and a concrete roadbed is installed on top of the buoyancy blocks.

[0031] The embankment wall minimizes flooding caused by high tides, large waves, and tsunamis, and also prevents the artificial island from drifting. Furthermore, even if flooding occurs due to high tides, large waves, or tsunamis, the floating structure has sufficient buoyancy, reducing the load on the artificial ground. In addition, the artificial ground has the bearing capacity to support the weight of the artificial island at low tide, thus minimizing the subsidence of the artificial island and the artificial ground supporting it.

[0032] The method for constructing an artificial island using buoyancy blocks according to claim 5 of the present invention, in claim 4, is such that the artificial ground is formed to have a predetermined bearing capacity by sand compaction after bringing in and leveling reclaimed soil, thereby enabling it to support the weight of the artificial island at low tide.

[0033] The method for constructing an artificial island using buoyancy blocks according to claim 6 of the present invention, in claim 4, provides that the bearing capacity of the artificial ground is greater than or equal to the weight of the artificial island, and the buoyancy of the floating structure is less than or equal to the weight of the artificial island. As a result, even when flooding occurs due to high tide, large waves, or tsunamis, the floating structure has sufficient buoyancy, thereby reducing the load on the artificial ground, and furthermore, at low tide, the artificial ground can support the weight of the artificial island. [Brief explanation of the drawing]

[0034] [Figure 1] Figure 1 is a longitudinal cross-sectional view showing a portion of a megafloat constructed using the artificial island construction method employing the buoyancy blocks of the present invention. [Figure 2] Figure 2 is a perspective view of a hollow block used in the buoyancy block for artificial islands according to the present invention. [Figure 3] Figure 3 is a front view of a hollow block used in the buoyancy block for artificial islands according to the present invention. [Figure 4] Figure 4 is a plan view showing a portion of a megafloat under construction using the construction method for artificial islands utilizing the buoyancy blocks of the present invention. [Figure 5] Figure 5 is a plan view showing the arrangement of hollow blocks in one section of Figure 4. [Figure 6] Figure 6 is a plan view of a floating megafloat showing unbonded PC steel materials installed on a floating structure with buoyancy blocks. [Modes for carrying out the invention]

[0035] The present invention relates to buoyancy blocks for artificial islands and a method for constructing artificial islands using these buoyancy blocks, and concerns artificial islands 1 that are installed by reclaiming land from the sea, lakes, rivers, etc., and are used for purposes such as airports, ports, solar power plants, thermal power plants, nuclear power plants, wave power plants, oil storage bases, exhibition halls, restaurants, leisure facilities, simulated experience facilities, breakwaters, and mooring piers. In particular, when used for airports where large passenger aircraft such as jumbo jets take off and land, the runway length becomes enormous, around 4000m, and is therefore called a megafloat (giant artificial floating island).

[0036] Such an artificial island 1 comprises a floating structure 2 on which various facilities are installed, and a buoyancy block 3 that provides buoyancy to the floating structure 2. In this embodiment, an artificial island 1 used in large facilities such as airports will be described in detail with reference to the drawings. [Examples]

[0037] <Buoyancy blocks for artificial islands> In Figure 1, 1 is an artificial island, 2 is a floating structure, and 3 is a buoyancy block. This buoyancy block 3 consists of a hollow concrete block 4 (product name: Super Pokhara) shown in Figures 2 and 3, and a buoyancy material 6 with a specific gravity lower than water, which is placed in the hollow part 5 inside the hollow block 4.

[0038] This hollow block 4 has a hollow section 5 formed inside the block body, which is made up of six faces, with a volume of 60% or more of the total volume. Openings 7 are formed on all or part of the six faces, allowing the hollow section 5 to pass through to the outside of the block body. These openings 7 are for installing the buoyancy material 6 in the hollow section 5. After the buoyancy material 6 is installed in the hollow section 5, all or part of the openings 7 are closed by the closing section 16.

[0039] Figure 2 of this embodiment shows a state in which openings 7 are formed on the top and side surfaces, and the openings 7 on the bottom and other side surfaces are closed by closing parts 16. For example, after installing the buoyancy material 6 through the openings 7 on the top and side surfaces, all the openings 7 may be closed with the closing parts 16, or the openings 7 may be left as they are.

[0040] Furthermore, the buoyancy material 6 is provided in the hollow section 5 of the hollow block 4, has a specific gravity lower than water, and its volume is set to 60% or more of the total volume to match the hollow section 5. The material used may be foamed resin such as expanded polystyrene (EPS), expanded polyethylene (EPE), expanded polypropylene (EPP), pumice, or closed-cell foam beads, and one or more of these materials may be used in combination.

[0041] In this embodiment, the volume of the hollow portion 5 and buoyancy material 6 of the buoyancy block 3 is set to 60% or more, but it is more desirable to set it to 80% or more. When it is set to 80% or more, sufficient strength can be maintained, and costs can be reduced, such as by reducing the material cost of concrete.

[0042] For the installation of the buoyancy material 6 into the hollow section 5, one of the following materials is used: expanded polystyrene (EPS), expanded polyethylene (EPE), expanded polypropylene (EPP), or other foamed resins, pumice, or closed-cell foamed beads, which are filled through the opening 7. However, the raw materials such as foamed resin may be foamed within the hollow section 5. Furthermore, two or more of these buoyancy material 6 materials may be used in combination.

[0043] Furthermore, if the hollow block 4 is made of precast concrete, that is, manufactured in a factory and transported to the construction site of the artificial island 1, there is a possibility that cracks or other damage may occur due to vibrations during transport. Therefore, reinforcing bars 8 may be provided on each side of the hexahedron as shown in Figure 3.

[0044] Furthermore, these hollow blocks 4 can be manufactured at the construction site of artificial island 1. In this case, transportation constraints are eliminated, saving on transportation costs. Moreover, it becomes possible to manufacture larger buoyancy blocks 3 using larger hollow blocks 4, thus reducing the effort required for manufacturing and construction.

[0045] The buoyancy material 6 is installed in the hollow section 5 through the opening 7 when manufacturing the hollow concrete block 4 at the factory or construction site of the artificial island 1. After the buoyancy material 6 is installed in the hollow section 5, all or part of the opening 7 is closed with the closing section 16.

[0046] <Floating Structures> Next, the floating structure 2 of artificial island 1 will be described in detail with reference to Figures 1 to 6. The floating structure 2 is equipped with a concrete side wall 9 whose upper end is above the surrounding water surface in order to separate the installation site for the artificial island 1 from the surrounding water. On the outer side of this side wall 9, i.e., the seawater side, there is an embankment wall 10 whose upper end is above the surrounding water surface, similar to the side wall 9, and whose surrounding area has been hardened and improved. This embankment wall 10 can prevent the artificial island 1 from drifting due to large waves or tsunamis, and can also protect the artificial island 1 from debris carried by the waves.

[0047] An artificial ground 11 is formed inside the side wall 9. This artificial ground 11 consists of reclaimed soil 11A brought inside the side wall 9 and sand compaction piles 11B, which are formed by inserting steel pipes into a portion of the reclaimed soil 11A, filling the pipes with sand, etc., and compacting them by vibration. By using this sand compaction method, the artificial ground 11 becomes a strong ground with a predetermined bearing capacity.

[0048] A concrete base 12 is formed on the artificial ground 11 created in this manner. The buoyancy blocks 3 are laid across the entire surface of this base 12 and stacked on top of them. In this embodiment shown in Figure 1, the blocks are stacked in three layers to provide a predetermined amount of buoyancy, but the size and number of buoyancy blocks 3 can be changed as appropriate.

[0049] Furthermore, the top surface of the uppermost buoyancy block 3 is located above the surrounding water surface, and a concrete runway base 13, which serves as a runway for airplanes and other aircraft, is provided on top of this uppermost buoyancy block 3.

[0050] Furthermore, the 14 shown in Figures 1, 4, 5, and 6 is a bulkhead that evenly partitions each of the 3 buoyancy block groups and supports the runway base 13 from below, preventing it from bending as much as possible. Like the side wall 9, the upper end of this bulkhead 14 is located above the surrounding water surface.

[0051] Furthermore, as shown in Figure 6, 15 is an unbonded supra PC steel bar, which is arranged in a parabolic shape at the same time as the reinforcement bars (not shown) are placed when the runway base 13 is poured. After the concrete hardens, the runway base 13 is prestressed by tensioning the unbonded PC steel bar 15 using a special jack. This causes the unbonded PC steel bar 15 to exert an upward lifting force, counteracting the load.

[0052] By embedding the unbonded PC steel members 15 in the runway base 13 in this manner, strength against upper loads, impact loads, etc., can be ensured, and cracking and corrosion deterioration of the steel members can also be prevented. Furthermore, in this embodiment, the wiring angle of the unbonded PC steel members 15 is set to 45 degrees as a measure against elongation.

[0053] Next, the relationship between the self-weight and buoyancy of the artificial island 1, and furthermore, the bearing capacity of the artificial ground 11, will be explained with reference to Table 1.

[0054] [Table 1]

[0055] As shown in Table 1, the self-weight of the artificial island 1 is set to be less than or equal to the bearing capacity of the artificial ground 11. This ensures that even when the buoyancy of the artificial island 1 becomes zero at low tide, it can still be supported by the artificial ground 11. In this embodiment, the self-weight of the artificial island 1 (weight per unit area) is 36,480 N / m2, and the bearing capacity of the artificial ground 11 (bearing capacity per unit area) is 50,000 N / m2.

[0056] Furthermore, the weight of the artificial island 1 is set to be greater than or equal to the buoyancy of the floating structure 2. This prevents the artificial island 1 from floating up at high tide. In this embodiment, the weight of the artificial island 1 (weight per unit area) is 36,480 N / m2, and the buoyancy of the artificial island 1 at high tide (buoyancy per unit area) is 30,000 N / m2.

[0057] <Construction method for artificial islands using buoyancy blocks> The construction method for artificial island 1, as described above, will be explained below. First, a reinforced embankment wall 10 is formed around the construction site, and after enclosing the area with the embankment wall 10, the seawater inside is drained. As this exposes the clayey old seabed, a temporary access road for construction is created using a belt conveyor, transport vehicles, and construction machinery. Next, a concrete side wall 9 is formed inside the embankment wall 10, with its upper end positioned at least above the sea level.

[0058] Subsequently, an artificial ground 11 is formed on the exposed seabed. This artificial ground 11 is formed by ground improvement work on the reclaimed soil 11A. The reclaimed soil 11A is transported to a predetermined height on which the bottom surface of the floating structure 2 of the artificial island 1 is placed, mixed and stirred with a cement-based solidifying agent, compacted, and then multiple sand compaction piles are formed using the sand compaction method. These sand compaction piles make it possible to achieve a bearing capacity (bearing capacity per unit area) of 50,000 N / m2 for the artificial ground 11.

[0059] The concrete base 12 of the floating structure 2 will be poured onto the artificial ground 11 that has undergone such improvement work. By forming a box-shaped structure higher than the sea level with this base 12 and the side walls 9, the intrusion of seawater can be prevented as much as possible. Furthermore, since the space inside the box-shaped structure enclosed by this base 12 and the side walls 9 is divided into a grid of predetermined sizes by partition walls 14, the distortion of the floating structure 2 due to shaking such as earthquakes can be prevented as much as possible.

[0060] Then, multiple buoyancy blocks 3 are laid out and stacked in the space partitioned by the base plate 12, side walls 9, and bulkheads 14. At this time, at least the buoyancy blocks 3 located on the outermost periphery are installed with their side closure portions 16 facing outwards from the floating structure 2, that is, towards the side walls 9. In this way, in the case of a structure without side walls 9, the side closure portions 16 of the buoyancy blocks 3 act as walls in place of the side walls 9.

[0061] Here, as mentioned above, the buoyancy block 3 is manufactured in a factory, and the buoyancy material 6 may be installed in the hollow section 5 of the hollow block 4 during manufacturing, or the buoyancy material 6 may be installed in the hollow block 4 that has been transported at the construction site. By preparing multiple such buoyancy blocks 3, the buoyancy (buoyancy per unit area) of the artificial island 1 can be set to 30,000 N / m2.

[0062] Furthermore, the hollow block 4 may be manufactured at the construction site, and the buoyancy material 6 may be installed in the hollow portion 5 of the hollow block 4 during manufacturing. In this case, transportation by truck or other means is unnecessary, allowing for larger buoyancy blocks 3 in terms of size and weight, thereby improving construction workability.

[0063] After installing the buoyancy blocks 3 on the floating structure 2, a concrete runway base 13 is installed on the upper surface of the box-shaped structure, with unbonded PC steel bars 15 embedded at a wiring angle of 45 degrees. This runway base 13 closes the upper surface of the space partitioned by the base 12, side walls 9, and bulkheads 14, thereby minimizing the intrusion of seawater into the floating structure 2 due to large waves, tsunamis, etc.

[0064] As described in detail above, the buoyancy block 3 for an artificial island according to claim 1 of the present invention constitutes a floating structure 2 by arranging multiple blocks at appropriate locations on the artificial island 1, and is equipped with a buoyancy material 6 that generates buoyancy,

[0065] It consists of a concrete hollow block 4 with a hollow section 5 formed inside the block body which is made up of hexahedrons, and a buoyancy material 6 which is installed in the hollow section 5 of the hollow block 4 and has a specific gravity less than that of water.

[0066] The hollow block 4 is provided with openings 7 formed on all or part of its six sides, which allow the hollow portion 5 to pass through to the outside of the block body, and closing portions 16 that close all or part of the openings 7 after the buoyancy material 6 is installed in the hollow portion 5.

[0067] By making the volume of the hollow portion 5 of the hollow block 4 60% or more of the total volume, and by making the volume of the buoyancy material 6 provided in the hollow portion 5 60% or more, a buoyancy block with sufficient buoyancy is obtained.

[0068] By appropriately arranging multiple buoyancy blocks 3 with suitable buoyancy on the floating structure 2 of the artificial island 1, the sinking of the artificial island 1 can be prevented as much as possible.

[0069] The buoyancy block for an artificial island according to claim 2 of the present invention is a buoyancy block 3 having sufficient buoyancy, in which the buoyancy material 6 is installed by combining one or more types of foamed resins such as expanded polystyrene (EPS), expanded polyethylene (EPE), and expanded polypropylene (EPP), pumice, and closed-cell foamed beads. In addition, if the buoyancy block of the artificial island is damaged by an air raid or the like, a sealed plastic bottle or a ball filled with gas such as air can be used as the buoyancy material 6 as an emergency measure.

[0070] Furthermore, these buoyancy materials 6 are installed after the manufacture of the hollow concrete blocks 4 and then transported to the construction site. However, the buoyancy materials 6 may be installed after the hollow blocks 4 have been transported to the construction site of the artificial island 1, or the buoyancy materials 6 may be installed after the hollow blocks 4 themselves have been manufactured at the construction site of the artificial island 1. In this way, it is possible to flexibly respond to the conditions of the construction site, thereby improving the work efficiency of the construction of the artificial island 1.

[0071] In particular, when manufacturing hollow concrete blocks 4 at the construction site of artificial island 1 and installing buoyancy material 6 to produce buoyancy blocks 3, the elimination of transportation constraints saves on transportation costs. Furthermore, it becomes possible to manufacture larger buoyancy blocks using larger hollow blocks 4, thus reducing the effort required for manufacturing and construction. This makes it possible to reduce construction costs.

[0072] The buoyancy block 3 for an artificial island according to claim 3 of the present invention is such that, in claim 1, the concrete block body of the hollow block 4 is provided with reinforcing bars 8 on each side of the hexahedron, thereby minimizing damage to the hollow block 4 or the buoyancy block 3 during transportation.

[0073] The method for constructing an artificial island 1 using a buoyancy block 3 according to claim 4 of the present invention is a method for constructing an artificial island 1 using a buoyancy block 3 that is equipped with a buoyancy material 6 that generates buoyancy, wherein a floating structure 2 is formed by arranging a plurality of buoyancy blocks 3 in appropriate locations on the artificial island 1,

[0074] The buoyancy block 3 is composed of a concrete hollow block 4 with a hollow section 5 formed inside a block body made of six hexahedrons, a buoyancy material 6 having a specific gravity less than water and installed in the hollow section 5 of the hollow block, openings 7 formed on all or part of the six faces of the hollow block 4 that pass between the hollow section 5 and the outside of the block body, and a closing section 16 that closes all or part of the openings 7 after the buoyancy material 6 is installed in the hollow section 5, thereby providing sufficient buoyancy.

[0075] Furthermore, in order to separate the installation site for the artificial island 1 from the surrounding water, an embankment wall 10 whose upper end is located above the surrounding water surface is provided, and reclaimed soil 11A is brought into the area enclosed by this embankment wall 10 to create an artificial ground 11 having a predetermined bearing capacity.

[0076] The floating structure 2 consists of a concrete base 12 installed on the artificial ground 11 and a plurality of buoyancy blocks 3 installed on the base 12. After ground improvement work is carried out on the artificial ground 11, the base 12 is installed, and a plurality of buoyancy blocks 3 are laid across the entire upper surface of the base 12 so that the upper surface of each block is above the surrounding water level, and a concrete roadbed 13 is installed on top of the buoyancy blocks 3.

[0077] The embankment wall 10 minimizes flooding caused by high tide, large waves, and tsunamis, and also prevents the artificial island 1 from drifting. Furthermore, even if flooding occurs due to high tide, large waves, or tsunamis, the floating structure 2 has sufficient buoyancy, which reduces the load on the artificial ground 11. Moreover, the artificial ground 11 has bearing capacity that can support the weight of the artificial island at low tide, thus minimizing the subsidence of the artificial island 1 and the artificial ground 11 supporting it.

[0078] The construction method for an artificial island 1 using the buoyancy block 3 according to claim 5 of the present invention is as follows: In claim 4, the artificial ground 11 is formed by bringing in reclaimed soil 11A, mixing and stirring it with a cement-based solidifying agent, leveling it by compaction, and then using a sand compaction method to have a predetermined bearing capacity, thereby enabling it to support the weight of the artificial island 1 at low tide.

[0079] The construction method for an artificial island 1 using the buoyancy block 3 according to claim 6 of the present invention, in claim 4, is achieved by making the bearing capacity of the artificial ground 11 greater than or equal to the weight of the artificial island 1, and the buoyancy of the floating structure 2 less than or equal to the weight of the artificial island 1. As a result, even in the event of flooding due to high tide, large waves, or tsunamis, the floating structure 2 will have sufficient buoyancy, thereby reducing the load on the artificial ground 11, and furthermore, at low tide, the artificial ground 11 will be able to support the weight of the artificial island 1. [Industrial applicability]

[0080] In the embodiments described above, the buoyancy block 3 for artificial islands of the present invention is used to prevent the artificial island 1 from floating up by making its own weight greater than the buoyancy of the floating structure 2. However, by conversely making the buoyancy of the floating structure 2 greater than the own weight of the artificial island 1, the invention can also be applied to artificial floating islands installed on the surface of water such as the sea, lakes, and rivers. [Explanation of Symbols]

[0081] 1 artificial island 2. Floating structures 3 Buoyancy Blocks 4 Hollow Block 5 Hollow part 6 Buoyancy material 7 Opening 8 Reinforcement bars 9 side wall 10. Embankment wall 11 Artificial ground 11A Landfill soil 11B Sand Compaction Pile 12 Bottom board 13. Trackbed 14 Bulkhead 15 Unbonded PC steel 16 Occlusion

Claims

1. In an artificial island buoyancy block, which is equipped with a buoyancy material that generates buoyancy, and which constitutes a floating structure by arranging multiple blocks in appropriate locations on the artificial island, A hollow concrete block having a hollow section formed inside a block body consisting of six hexahedrons, and a buoyancy material having a specific gravity less than that of water, installed in the hollow section of the hollow block, A buoyancy block for an artificial island, characterized in that the volume of the hollow portion of the hollow block is 60% or more of the total volume, and the volume of the buoyancy material provided in the hollow portion is 60% or more.

2. The buoyancy material is one or more types of foamed resins such as expanded polystyrene (EPS), expanded polyethylene (EPE), and expanded polypropylene (EPP), pumice, and closed-cell foam beads, as described in claim 1, making it a buoyancy block for an artificial island.

3. The buoyancy block for an artificial island according to claim 1, characterized in that the concrete block body of the hollow block has reinforcing bars provided on each side of the hexahedron.

4. In a method for constructing an artificial island using buoyancy blocks equipped with buoyancy material that generates buoyancy, which are arranged in multiple locations on the artificial island to form a floating structure, The buoyancy block consists of a hollow concrete block with a hollow section formed inside a block body made of six hexahedrons, and a buoyancy material with a specific gravity lower than water that is placed inside the hollow section of the block. In order to separate the installation site for the artificial island from the surrounding water, an embankment wall is provided whose upper end is located above the surrounding water surface, and reclaimed soil is brought into the area enclosed by the embankment wall to create an artificial ground with a predetermined bearing capacity. The floating structure consists of a concrete base plate installed on the artificial ground and a plurality of buoyancy blocks installed on the base plate. After leveling the artificial ground, the base slab is installed. Multiple buoyancy blocks are laid out across the entire upper surface of the base plate such that their upper surfaces are positioned above the surrounding water level. A method for constructing an artificial island using buoyancy blocks, characterized in that a concrete roadbed is installed on top of the aforementioned buoyancy blocks.

5. The method for constructing an artificial island using buoyancy blocks according to claim 4, characterized in that the artificial ground is formed to have a predetermined bearing capacity by a sand compaction method after bringing in and leveling reclaimed soil.

6. A method for constructing an artificial island using buoyancy blocks according to claim 4, characterized in that the bearing capacity of the artificial ground is greater than or equal to the weight of the artificial island, and the buoyancy of the floating structure is less than or equal to the weight of the artificial island.

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