Underwater construction method

Abstract

To provide a system and a method for construction of a structure in water, allowing construction of the structure in water with high accuracy, without requiring a large-scale water cut-off structure or an immersion structure, or a diver.SOLUTION: A construction method uses a construction system for forming a structure in water by laminating a hydraulic mixture continuously discharged from a movable discharging part. A sheet pile cut-off structural body 1 is formed by closing the periphery of a construction position of the structure with sheet pile members 11, a laminated wall 31 is formed by bonding the hydraulic mixture to the face of a side provided with the structure of the sheet pile members 11 and laminating from a sheet pile cut-off structural body water bottom part 12, a composite wall 41 is formed by integrating the sheet pile members 11 and the laminated wall 31, a laminated bottom slab 32 is formed by laminating the hydraulic mixture to the sheet pile cut-off structural body water bottom part 12 surrounded by the composite wall 41, a composite cut-off structural body 4 is formed by integrating the composite wall 41 and the laminated bottom slab 32, and the structure is constructed in an underwater part 43 in a caisson formed in the composite cut-off structural body 4.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention ,water This relates to a construction method for structures within the facility. [Background technology]

[0002] In a construction method for underwater structures such as bridge piers, the area where the structure will be installed is first enclosed and sealed off with a large-scale water-stopping structure such as a steel pipe sheet pile to prevent water from entering the water-stopping structure, and the water inside the water-stopping structure is then drained. This allows a working space to be secured inside the water-stopping structure, and the structure can be constructed (see, for example, Patent Document 1). Another construction method is to fabricate a submerged structure (caisson) in the shape of a box or the like on land, such as a port dock, and tow it to the construction site, where it is filled with water and allowed to sink to a specified water bottom. A commonly used construction method is to build a structure such as an underwater tunnel by sequentially pouring filling materials suitable for use underwater, such as underwater non-segregating concrete, into the submerged caisson using equipment that prevents material separation underwater, such as a tremie pipe (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-303096 [Patent Document 2] JP 2005-330718 A Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, the above-mentioned underwater structure construction methods require large-scale water-stopping structures such as steel pipe sheet piles and large-scale structures such as caissons to deal with the large stresses that occur in water-stopping structures due to water pressure and water leakage from sheet pile joints, which poses issues such as longer construction periods and higher construction costs due to reduced work efficiency. In addition, when controlling the accuracy of the construction of structures, divers may be required to go underwater to the site to control the accuracy, but the labor cost of divers is high, and the number of divers is on the decline, so there is the issue that it will become more difficult to secure personnel in the future.In addition, there is the issue that the construction costs will be high because of the fact that people are directly sent to a special underwater construction site, and efficiency in terms of construction time, cost, and safety is reduced depending on the various conditions of the construction site (water transparency, flow speed, water temperature, etc.).

[0005] The present invention has been made in consideration of the above circumstances, and makes it possible to construct structures underwater with high precision without the need for large-scale water-stopping structures or submerged structures, or for divers to dive to the site, thereby reducing the construction costs and shortening the construction period for structures constructed underwater. ,water The object of the present invention is to provide a method for constructing a structure in a building. [Means for solving the problem]

[0008] above In order to achieve the above object, the method for constructing an underwater structure according to the present invention comprises the steps of: A method for constructing a structure underwater, comprising stacking hydraulic mixture discharged from a movable discharge unit of an additive manufacturing apparatus having a mechanism for continuously discharging a soft hydraulic mixture from the discharge unit, thereby forming a structure underwater, the additive manufacturing apparatus comprising: a hopper provided on water and storing the hydraulic mixture; a pump provided on water and connected to the hopper and capable of supplying the hydraulic mixture from the hopper; a controller provided on the pump and controlling the operation of the pump; a hose having one end connected to the pump and capable of delivering the hydraulic mixture supplied from the pump; a nozzle connected to the other end of the hose and discharging the hydraulic mixture delivered through the hose; and an electromagnetic valve provided on the nozzle and controlling the discharge amount of the hydraulic mixture, the hose being a hose having a length sufficient to reach the bottom surface of the water at a construction position of the structure, the hose being a hose provided on water and ... A method for constructing a structure underwater using a construction system for a structure, comprising: closing off the periphery of the construction position of the structure with sheet pile members having a height equal to or greater than the surrounding water depth to form a sheet pile water-stopping structure; adhering the hydraulic mixture discharged from the nozzle of the additive manufacturing device to the surface of the sheet pile members on which the structure is to be installed, and stacking the mixture from the water bottom surface to form a laminated wall; and forming a composite wall in which the sheet pile members and the laminated wall are integrated together. do. The method for constructing an underwater structure according to the present invention comprises the steps of:The hydraulic mixture discharged from the nozzle of the additive manufacturing device is laminated on the water bottom surface surrounded by the synthetic wall to form a laminated bottom plate, and the synthetic wall and the laminated bottom plate are integrated to form a synthetic water-stopping structure, and the structure is constructed in the underwater part of a box formed inside the synthetic water-stopping structure. You may do so.

[0009] With the above-mentioned structure, the composite wall and the laminated base slab are formed by integrating the sheet pile members and the laminated wall that form the sheet pile waterproof structure, and the composite waterproof structure is integrated, which can significantly improve the bending strength and rigidity. Therefore, it becomes possible to firmly support the external forces such as water pressure and tidal currents. In addition, by forming the composite water-stopping structure and the underwater part inside the box with a simple structure, it is possible to construct a structure with excellent water-stopping performance without leaking water, which is integrated with laminated walls without joints underwater, without the need for large-scale water-stopping structures such as steel pipe sheet piles or large-scale submerged structures such as caissons. This makes it possible to reduce the construction cost and shorten the construction period for structures constructed underwater.

[0010] In addition, in the method for constructing an underwater structure according to the present invention, underwater non-separable concrete may be poured upward from the top surface of the laminated base plate into the underwater portion of the box while replacing the water stored in the underwater portion of the box with the underwater non-separable concrete to form an intra-box filling structure, and the synthetic water-stopping structure and the intra-box filling structure may be integrated to construct the structure.

[0011] With the above-mentioned configuration, it is possible to pour the hydraulic mixture into the underwater part of the box in a short time after forming the synthetic water-stopping structure. It is also possible to construct the structure underwater without requiring divers to go to the site. Therefore, it is possible to reduce the construction cost and shorten the construction period of the structure underwater.

[0012] In addition, in the method of constructing a structure underwater according to the present invention, after forming the synthetic water-stopping structure, the water stored in the underwater portion of the box is completely drained to form a void portion inside the box, and construction material that can be used in air is poured into the void portion inside the box to construct the structure.

[0013] With the above-mentioned configuration, the structure that was constructed underwater can be constructed in the air by forming an inner space inside the box inside the synthetic water-stopping structure. Therefore, it is possible to easily perform quality control of the structure to be constructed. In addition, since the construction can be performed in the air, it is possible to freely select the shape and construction method of the structure to be constructed.

[0014] In the underwater structure construction method according to the present invention, the sheet pile member may have at least one of studs and uneven grooves formed on the surface on which the laminated wall is to be provided.

[0015] By having the above-mentioned configuration, it is possible to increase the adhesive strength between the steel sheet pile and the laminated wall, and it is possible to form a stronger composite water-stopping structure. Effect of the Invention

[0016] According to the present invention, it is possible to construct structures underwater without the need for large-scale water-stopping structures or submerged structures, or for divers to descend to the site, making it possible to reduce the cost of constructing structures underwater and shorten the construction period. ,water It is possible to provide a method for constructing a structure in a building. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a perspective view of a steel sheet pile water stop structure in an example of a construction method for an underwater structure according to an embodiment of the present invention. [Diagram 2] 2 is a view taken along the arrow A in FIG. 1. [Diagram 3]2 is a partial cross-sectional view taken along line B-B' in FIG. 1, showing the construction status of a laminated structure in an example of an underwater structure construction method according to an embodiment of the present invention. FIG. [Figure 4] FIG. 2 is a perspective view of a synthetic water-stopping structure in an example of a method for constructing an underwater structure according to an embodiment of the present invention. [Diagram 5] 5 is a partial cross-sectional view taken along line D-D' in FIG. 4, showing the construction status of a filling structure in an example of a method for constructing an underwater structure according to an embodiment of the present invention. FIG. [Figure 6] 1 is a perspective view of an underwater structure in an example of a method for constructing an underwater structure according to an embodiment of the present invention. [Figure 7] 7 is a cross-sectional view taken along line E-E' in FIG. 6. [Figure 8] 1 shows a synthetic water-stopping structure according to a modified example of an embodiment of the present invention, in which (a) shows a cross-sectional view of the modified example taken along line D-D' in FIG. 4, and (b) shows a top view seen from the F direction in (a). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an underwater structure construction system and an underwater structure construction method according to an embodiment of the present invention will be described with reference to Figures 1 to 8. In this embodiment, a structure to be constructed underwater is provided at a predetermined position on the seabed ground surface BW.

[0019] As shown in Figures 1 and 2, in the method for constructing an underwater structure according to this embodiment, first, a plurality of steel sheet piles 11 (sheet pile members) having a height equal to or greater than the depth of the surrounding seawater W are driven into the seabed ground UWG around the construction position of the structure to be constructed underwater at a driving depth that will not cause the structure to overturn due to external forces such as the water pressure of the seawater W or tidal force, and then the construction position is closed off. After sealing off the construction position with the steel sheet piles 11, adjacent steel sheet piles 11, 11 are joined without any gaps to seal off the surrounding seawater W, thereby constructing a steel sheet pile water stop structure 1 (sheet pile water stop structure). Depending on the type of steel sheet pile 11, the joints may be constructed when the piles are cast, in which case there is no need to join them again.

[0020] In this embodiment, the steel sheet pile water stop structure 1 is composed of an aerial section 1a where the steel sheet pile 11 is above the sea surface WL, an underwater section 1b where the steel sheet pile 11 is in seawater W, and an underground section 1c where the steel sheet pile 11 is driven into the seabed ground UWG. When a structure to be constructed underwater is provided below the sea surface WL, the steel sheet pile water stop structure 1 does not need to be composed of an aerial section 1a.

[0021] As shown in Fig. 2, the outer shape of the steel sheet pile 11 is a plate-like member that is elongated in the direction in which it is driven into the seabed ground UWG. The steel sheet pile 11 has a certain strength against external forces such as the water pressure of seawater W and tidal force. For example, the steel sheet pile 11 has a strength such that buckling does not occur in the steel sheet pile 11 driven into the seabed ground UWG due to external forces such as the water pressure of seawater W and tidal force. For example, steel material is used as the material.

[0022] In addition, the method of joining adjacent steel sheet piles 11, 11 is not limited as long as there is no significant water ingress between the joined steel sheet piles 11, 11. For example, adjacent steel sheet piles 11, 11 may be overlapped with a part of each without a gap and joined with fixing metal fittings such as bolts. In addition, adjacent steel sheet piles 11, 11 may be processed for joining.

[0023] 1, the external shape of the steel sheet pile water stop structure 1 in this embodiment is a rectangular tube shape. The external shape of the steel sheet pile water stop structure 1 is not limited as long as it forms a steel sheet pile water stop structure water bottom part 12 that can adequately construct a structure to be constructed underwater and has a strength that is not destroyed by external forces such as the water pressure of seawater W and tidal force. For example, the steel sheet pile water stop structure 1 may be formed into a cylindrical shape, an elliptical cylindrical shape, a corrugated shape, or a rib type (deck plate shape) in which multiple rectangular shapes are formed in a direction facing the inside of the steel sheet pile water stop structure 1, taking into consideration buckling of the steel sheet pile 11 due to water pressure. Moreover, the steel sheet pile 11 is not limited to the present embodiment as long as the construction area is closed off by the steel sheet pile water stop structure 1. For example, the construction area may be closed off by using a steel pipe sheet pile.

[0024] Next, in order to explain the underwater structure construction method according to this embodiment, a structure construction system will be explained with reference to FIG. As shown in Fig. 3, a construction system 2 for an underwater structure in this embodiment (hereinafter, abbreviated as the construction system 2) has an additive manufacturing device 20 equipped with a mechanism for continuously discharging a hydraulic mixture 21 to a loading vessel 28 capable of moving on water. The construction system 2 forms a structure underwater by layering the discharged hydraulic mixture 21 in the underwater section 1b. The additive manufacturing apparatus 20 also has a hopper 22, a pump 23, a controller 24, a hose 25, a nozzle 26 (discharge portion), and an electromagnetic valve 27 as mechanisms for movably and continuously discharging the hydraulic mixture 21.

[0025] The hopper 22 is provided on the loading vessel 28, and is capable of temporarily storing a large amount of hydraulic mixture 21 for a period of time during which a predetermined quality is maintained. The external shape of the hopper 22 is a funnel shape with a wide opening on the side for feeding the hydraulic mixture 21. The external shape of the hopper 22 is not limited to the external shape of this embodiment, so long as it can temporarily store the hydraulic mixture 21 and supply it to the hose 25. For example, it may be a rectangular cylinder shape with an open top.

[0026] The pump 23 is connected to the downstream side of the hopper 22. In addition, the pump 23 is capable of adjusting the supply amount of the hydraulic mixture 21 supplied from the hopper 22 by controlling the driving of the pump 23 using a controller 24 provided in the pump 23.

[0027] The hose 25 has one end connected to the pump 23 and is arranged so as to be able to deliver the hydraulic mixture 21 supplied from the pump 23. The hose 25 has a hollow cylindrical shape and is long enough to reach the seabed ground surface BW (the water bottom part 12 of the steel sheet pile waterstop structure) at the construction position of the structure to be constructed underwater. The hose 25 is made of an elastic material. For example, rubber is used as the material. With the above-mentioned configuration, the hose 25 is movable within a range taking into consideration the length of the hose 25, and is deformable within a range taking into consideration the elasticity of the hose 25.

[0028] The nozzle 26 is connected to the other end of the hose 25. The nozzle 26 continuously discharges the hydraulic mixture 21 delivered through the hose 25, and the discharge amount of the hydraulic mixture 21 is controlled by an electromagnetic valve 27. The nozzle 26 is movable within a range taking into consideration the length of the hose 25 to which it is connected, and is free to discharge in any direction within a range taking into consideration the elasticity of the hose 25 to which it is connected.

[0029] The additive manufacturing device 20 is not limited to the installation configuration of this embodiment as long as it is capable of continuously discharging the hydraulic mixture 21 from the seabed ground surface BW at the construction position of the structure to be constructed underwater by the additive manufacturing device 20. For example, it may be installed on another floating structure such as a barge, or it may be installed on the coast of land if the construction site is close to land and the hose 25 can reach the seabed ground surface BW at the construction position of the structure to be constructed underwater from land.

[0030] Furthermore, the additive manufacturing device 20 is not limited to this embodiment as long as it is provided with a mechanism for adjusting the amount of hydraulic mixture 21 supplied to the hose 25. For example, the hopper 22 and the hose 25 may be connected to provide a delivery path with a gentle slope through which the hydraulic mixture 21 can be delivered, and a valve that can be opened or closed manually or automatically may be provided at the connection between the delivery path and the hose 25 as a mechanism substituting the pump 23 and the controller 24, thereby providing a mechanism for adjusting the amount of hydraulic mixture 21 supplied to the hose 25.

[0031] The hydraulic mixture 21 has a softness that allows it to be easily molded in water when it is discharged, and also has a property of being difficult to diffuse in water. For example, underwater non-separating concrete or various cement-based materials that can be used in water (e.g., cement paste, mortar) are used. In addition, the manufacturing method of the hydraulic mixture 21 is not limited as long as a predetermined quality is ensured when the hydraulic mixture 21 is layered. For example, the hydraulic mixture 21 may be manufactured on land in advance, transported by another ship and anchored near the loading ship 28, and transferred to the hopper 22, or the loading ship 28 may be provided with a mechanism for manufacturing the hydraulic mixture 21, and the hydraulic mixture 21 may be manufactured on board the loading ship 28 and charged into the hopper 22. In addition, as long as a desired structure can be constructed underwater, there is no limitation on the method of laminating the hydraulic mixture 21. For example, the hydraulic mixture 21 may be extruded from the nozzle 26 and laminated, or the hydraulic mixture 21 may be sprayed onto the surface of the steel sheet pile 11 on which the structure is to be constructed and laminated.

[0032] Furthermore, if the hose 25 has a sufficient length to reach the seabed ground surface BW at the position where the structure is to be constructed, and the hydraulic mixture 21 can be delivered without leaking from the hose 25 during delivery, a mechanism for adjusting the length of the hose 25 may be provided. For example, the hose 25 may be configured by connecting a plurality of segments together without any gaps, and the length of the hose 25 may be adjusted according to the number of segments connected together, and a mechanism for adjusting the length of the hose according to the water depth of the discharge location of the hydraulic mixture 21 may be provided.

[0033] Furthermore, if the discharge position of the nozzle 26 is difficult to determine due to the hose 25, nozzle 26, and loading vessel 28 moving freely due to the tides and waves of the seawater W, the hose 25 may be provided with a mechanism for controlling the position of the hose 25. For example, the hose 25 may be provided with a robot arm that can be remotely operated on land and has a predetermined operability against swaying, such as not moving freely due to the tides and waves of the seawater W and not moving freely due to sea winds, or a gate-shaped frame may be provided on the loading vessel 28, and the hose 25 may be lowered to a position where the hydraulic mixture 21 is discharged.

[0034] In addition, if the discharge position of the nozzle 26 is difficult to determine due to the movement of the hose 25, the nozzle 26, and the loading ship 28 caused by the tides and waves of the seawater W, a mechanism for controlling the movement of at least one of the hose 25 and the nozzle 26 may be provided. For example, an underwater drone or an underwater camera that can be remotely operated on land may be provided to control the position where the hydraulic mixture 21 is discharged.

[0035] A method for constructing the synthetic waterproof structure 4 using the construction system 2 will be described. As shown in Figures 3 and 4, the hydraulic mixture 21 continuously discharged from the nozzle 26 is adhered to the surface of the steel sheet pile 11 constituting the steel sheet pile waterstop structure 1 on the side where the structure is to be constructed, and is layered from the seabed ground surface BW to the boundary between the underwater part 1b and the above-ground part 1a, forming a layered wall 31. Similarly, the hydraulic mixture 21 is layered on the water bottom part 12 of the steel sheet pile waterstop structure to form a layered bottom slab 32. The layered wall 31 and the layered bottom slab 32 thus formed are joined at the lower end of the layered wall 31 and the peripheral part of the layered bottom slab 32 to form a layered structure 3.

[0036] The steel sheet pile 11 and the laminated wall 31 are integrated to form a composite wall 41, and the composite wall 41 and the laminated bottom slab 32 are integrated to form a composite water-stopping structure 4. The underwater part 1b closed off by the composite water-stopping structure 4 is formed as the underwater part 43 inside the box. The upper surface of the laminated bottom slab 32 surrounded by the laminated wall 31 is formed as the bottom surface 42 of the composite water-stopping structure. In this way, when the seawater W inside the composite water-stopping structure 4 is drained, the steel sheet pile 11 resists in tension and the laminated wall 31 resists in compression against the bending stress caused by the action of water pressure from the steel sheet pile 11 side of the composite wall 41, and the composite wall 41 becomes a structure with significantly increased strength and rigidity. In addition, the laminated wall 31 is in a compressed state, so that it is difficult for cracks to occur, and the structure has high water-stopping performance with no risk of water leakage. In addition, it is desirable to provide studs or uneven grooves on the surface of the steel sheet pile 11 that comes into contact with the hydraulic mixture 21 in order to enhance adhesion to the hydraulic mixture 21 and integrate it with the layered wall 31.

[0037] The laminated wall 31 may be formed by adhering the hydraulic mixture 21 to the surface of the steel sheet pile 11 opposite to the surface on which the structure is to be constructed, and laminating the mixture from the seabed ground surface BW to the boundary between the underwater part 1b and the above-ground part 1a. In this way, the rust-proofing effect of the steel sheet pile 11 is improved. Moreover, the composite water stop structure 4 may be formed by integrating the two laminated walls 31, 31 formed as described above and the steel sheet pile 11 sandwiched between the two laminated walls 31, 31.

[0038] A method for constructing a structure underwater using the construction system 2 will be described. As shown in Fig. 5, the system has a configuration in which a casting device 5 equipped with a mechanism capable of casting underwater non-separation concrete 51 in a state in which the materials do not separate is provided on a loading vessel 56 capable of moving on water. The casting device 5 has a hopper 52, a pump 53, a hose 54, and a tremie pipe 55 as mechanisms for casting the underwater non-separation concrete 51 in a state in which the materials do not separate. The underwater non-separation concrete 51 does not easily separate even when allowed to fall freely in still water, and has excellent fluidity and the ability to be filled into narrow gaps by its own weight.

[0039] In addition, the hopper 52 and the pump 53 have the same mechanism and function as the hopper 22 and the pump 23 that constitute the additive manufacturing apparatus 20. Moreover, the hose 54 has one end connected to the pump 53 and the other end provided with a discharge port facing downward, and is formed so as to be able to discharge the underwater non-segregating concrete 51 delivered from the pump 53. The material of the hose 54 may be the same as that of the hose 25. Moreover, the hose 54 may be provided with a fixed shape and arrangement. For example, the cross-sectional shape (delivery cross-section) may always be fixed to a cylindrical shape.

[0040] The tremie pipe 55 has a length that allows it to approach the water bottom surface 42 of the synthetic water stop structure, and is provided as a pipe member having an internal cavity that can deliver the underwater non-separating concrete 51. The tremie pipe 55 is provided with a supply port at one end for receiving the underwater non-separating concrete 51 discharged from the discharge port of the hose 54 and supplying it to the submerged portion 43 inside the box, and a discharge port is formed at the other end that is close to the water bottom surface 42 of the synthetic water stop structure.

[0041] As shown in Figures 5 to 7, underwater non-separable concrete 51 is poured into the synthetic water-stopping structure from the bottom surface 42 through a tremie pipe 55, and the seawater W stored in the underwater part 43 inside the box is replaced with the underwater non-separable concrete 51 to form an inner-box filling structure 6, which is integrated with the synthetic water-stopping structure 4 to construct an underwater foundation structure 7 (underwater structure). As long as the underwater foundation 7 has the desired function, it is not limited to the configuration of this embodiment. For example, the underwater foundation 7 may be formed by filling the underwater portion 43 inside the box with earth and sand such as soil mortar and gravel.

[0042] When the underwater non-separation concrete 51 is poured through the tremie pipe 55, separation of the material is prevented by pouring the underwater non-separation concrete 51 while gradually pulling it up with the tip of the tremie pipe 55 always remaining in the poured underwater non-separation concrete 51. The tremie pipe 55 is not limited to the configuration of this embodiment as long as the underwater non-separation concrete 51 can be filled from the water bottom surface 42 of the synthetic water stop structure. For example, two or more tremie pipes may be used, or one tremie pipe may be branched midway to provide a plurality of pouring locations for the underwater non-separation concrete 51.

[0043] Next, the operation and effect of the underwater structure construction system and the underwater structure construction method according to the above-described embodiment will be described.

[0044] First, as shown in FIG. 3, a construction system 2 having a hopper 22, a pump 23, a controller 24, a hose 25, a nozzle 26, and an electromagnetic valve 27 is used as a mechanism for continuously and movably discharging hydraulic mixture 21 to a loading vessel 28 capable of moving on water. The hose 25 is equipped with an additive manufacturing device 20, and by using the construction system 2, it is possible to layer the hydraulic mixture 21 underwater at a desired position (the water bottom portion 12 of the steel sheet pile waterstop structure), making it possible to construct a structure underwater.

[0045] As shown in Figures 1 to 4, the hydraulic mixture 21 discharged by the additive manufacturing device 20 is adhered to the surface of the steel sheet pile 11 forming the sheet pile water stop structure 1 on the side where the structure is to be constructed, and is layered from the seabed ground surface BW to the boundary between the underwater part 1b and the above-ground part 1a to form a layered wall 31. Similarly, the hydraulic mixture 21 is layered on the water bottom part 12 of the steel sheet pile water stop structure to form a layered bottom slab 32. The steel sheet pile water stop structure 1 and the layered wall 31 are integrated to form a composite wall 41, and the composite wall 41 and the layered bottom slab 32 are integrated to form a composite water stop structure 4. The underwater part 1b closed off by the composite water stop structure 4 is formed as the underwater part 43 inside the box.

[0046] As shown in Figures 5 to 7, underwater non-separable concrete 51 is poured into the underwater part 43 of the box, which is closed off by the synthetic water-stopping structure 4 of this embodiment, using a pouring device 5 to pour it from the bottom surface 42 of the synthetic water-stopping structure, and the seawater W stored in the underwater part 43 of the box is replaced with the underwater non-separable concrete 51 to form an inner-box filling structure 6, which is integrated with the synthetic water-stopping structure 4 to construct an underwater foundation structure 7 (underwater structure).

[0047] By using the above construction system, it is possible to make the hose 25 reach the seabed ground surface BW (the water bottom part 12 of the steel sheet pile waterstop structure) at the construction position of the structure to be constructed underwater, and it is possible to discharge and layer the hydraulic mixture 21 from the nozzle 26 connected to the end of the hose 25 that has reached the water bottom surface. Therefore, by using the additive manufacturing device 20, it is possible to build a structure underwater.

[0048] In addition, by using the above construction method to form the synthetic water stop structure 4, it is possible to provide a water stop structure with significantly improved bending strength and rigidity. Therefore, it is possible to provide stronger support without leakage against external forces such as water pressure from seawater W and tidal currents. In addition, since the composite water-stopping structure 4 and the submerged portion 43 in the box are formed with a simple structure, it becomes possible to construct a structure underwater without requiring a large-scale water-stopping structure such as a steel pipe sheet pile or a large-scale submerged structure such as a caisson. Therefore, it becomes possible to reduce the construction cost and the construction period of a structure to be constructed underwater.

[0049] Moreover, by using the above construction method, it becomes possible to cast the underwater non-separating concrete 51 into the underwater part 43 of the box in a short time after forming the synthetic water-stopping structure 4. It also becomes possible to construct a structure underwater without the need for on-site work by divers. Therefore, it becomes possible to reduce the construction cost and the construction period of the structure underwater.

[0050] The above describes an embodiment of the underwater structure construction system according to the present invention, but the present invention is not limited to the above embodiment and can be modified as appropriate without departing from the spirit of the present invention.

[0051] For example, a modified example of this embodiment includes a method in which after the synthetic water-stopping structure 4 is formed, the seawater W stored in the underwater portion 43 of the box is completely drained to form a void portion inside the box, and construction material that can be used in the air is poured into the void portion inside the box, and the structure is constructed. Furthermore, when the seawater W stored in the underwater portion 43 inside the box is drained, the synthetic water-stopping structure 4 is subjected to stress due to large water pressure from the outside of the synthetic water-stopping structure 4. However, since the strength and rigidity are significantly increased by forming the composite wall 41, construction can be carried out safely without causing significant deformation of the composite wall 41.

[0052] By using the above construction method, a void space is formed inside the synthetic waterproof structure 4, so that the structure constructed underwater in the previous example can be constructed in the air. Therefore, it becomes possible to easily control the quality of the structure.

[0053] In addition, since construction can be performed in the atmosphere, it is possible to freely select the shape of the structure to be constructed and the construction method. For example, the structure may be further reinforced by placing reinforcing bars in the void inside the box. In addition, a formwork for the structure to be constructed in the void inside the box may be produced, and underwater concrete may be poured into the formwork to construct a structure of a shape other than the filled structure or a structure of a complex shape, and the composite structure may be constructed by integrating the formwork with the synthetic water-stopping structure.

[0054] In addition, when the seawater W stored in the underwater portion 43 of the box is completely drained and the void space inside the box is filled with construction materials to construct the underwater foundation structure 7, there are construction conditions that differ from those in the construction method of pouring underwater non-segregating concrete 51 into the underwater portion 43 of the box. For example, the construction material filled in the cavity inside the box can be cured to obtain the desired strength in air and can be used underwater. Also, the synthetic water-stopping structure 4 has a height that takes into consideration changes in the environment at the construction site and the work safety inside the cavity inside the box (for example, seawater W does not overtop or overflow into the cavity inside the box).

[0055] Another modified example of this embodiment is a method in which a support member 8 is provided inside a steel sheet pile water-stopping structure 1, the support member 8 being joined to the surface of a steel sheet pile 11 on which a structure will be installed, as shown in Figure 8. For example, the support member 8 is joined to any pair of opposing steel sheet piles 11, 11 in a braced state on the surface of the steel sheet pile waterstop structure 1 on which a structure is to be installed. When the steel sheet pile 11 is bonded to the steel sheet pile waterstop structure 1 having this configuration to form a laminated wall 31, the steel sheet pile 11, the laminated wall 31, and the support member 8 are integrated to form a composite waterstop structure 4. Therefore, by adding a simple configuration to the steel sheet pile waterstop structure 1, it is possible to form a composite waterstop structure 4 with improved bending strength and rigidity. In addition, when the support member 8 is bonded to the water bottom 12 of the steel sheet pile waterstop structure, the steel sheet pile 11, the laminated wall 31, the laminated base slab 32, and the support member 8 are integrated to form the composite waterstop structure 4, so that it is possible to further improve the bending strength and rigidity of the composite waterstop structure 4.

[0056] The external shape and configuration of the support member 8 are not limited as long as they improve the bending strength and rigidity of the composite waterstop structure 4. For example, as shown in Fig. 8, the support member 8 having a plate-like shape made of steel may be provided so as to form a cross shape inside the steel sheet pile waterstop structure 1, joined to a plurality of opposing steel sheet piles 11, and bonded to the water bottom part 12 of the steel sheet pile waterstop structure. Also, the support member 8 may be provided so as to form a radial shape inside the steel sheet pile waterstop structure 1.

[0057] In addition, in this embodiment, a method for constructing a structure in seawater W has been described, but the structure construction system and construction method according to the present invention can also be applied to freshwater rivers, lakes, and ponds. [Explanation of symbols]

[0058] 1. Steel sheet pile water stop structure (Sheet pile water stop structure) 1a Aerial part 1b underwater part 1c underground 11 Steel sheet piles (sheet pile members) 12 Steel sheet pile water stop structure water bottom part (Sheet pile water stop structure water bottom part) 2 Underwater structure construction system 20 Additive Manufacturing Equipment 21 Hydraulic mixture 22,52 Hopper 23,53 Pump 24 Controller 25,54 Hose 26 Nozzle (discharge part) 27 Solenoid valve 28,56 Loading vessels 3. Laminated structure 31 Laminated Wall 32 Laminated base plate 4 Synthetic water-stop structure 41 Composite wall 42 Synthetic water stop structure underwater bottom surface 43 Hakanai Underwater Area 5. Concrete pouring equipment 51 Underwater non-segregating concrete 55 Ptolemy tube 6 Box filling structure 7 Underwater foundation structures (underwater structures) 8 Shoring members W Seawater WL sea surface BW Seabed toposurface UWG submarine ground

Claims

1. A method for constructing a structure underwater, comprising stacking a hydraulic mixture discharged from a movable discharge unit of an additive manufacturing apparatus having a mechanism for continuously discharging a soft hydraulic mixture from the discharge unit to form a structure underwater, the method comprising: The additive manufacturing apparatus comprises: A hopper provided on water for storing the hydraulic mixture; a pump connected to the hopper and installed above water, capable of supplying the hydraulic mixture from the hopper; A controller provided in the pump and controlling the operation of the pump; a hose having one end connected to the pump and capable of delivering the hydraulic mixture supplied from the pump; a nozzle connected to the other end of the hose for discharging the hydraulic mixture delivered through the hose; an electromagnetic valve provided in the nozzle for controlling the amount of the hydraulic mixture discharged; Equipped with The hose has a sufficient length to reach the water bottom surface at a construction position of the structure, The periphery of the construction position of the structure is closed off with sheet pile members having a height equal to or greater than the water depth of the surrounding area to form a sheet pile water-stopping structure; The hydraulic mixture discharged from the nozzle of the additive manufacturing device is adhered to the surface of the sheet pile member on which the structure is to be provided, and stacked from the water bottom surface to form a stacked wall; The sheet pile member and the laminated wall form an integrated composite wall. A method for constructing structures underwater.

2. The hydraulic mixture discharged from the nozzle of the additive manufacturing device is laminated on the water bottom surface surrounded by the synthetic wall to form a laminated bottom plate; The composite wall and the laminated base plate form an integrated composite water-stopping structure, The structure is installed in the underwater portion of a box formed inside the synthetic water-stopping structure.

2. The method for constructing an underwater structure according to claim 1.

3. The underwater non-segregating concrete is poured upward from the upper surface of the laminated base plate into the underwater portion of the box while replacing the water stored in the underwater portion of the box with the underwater non-segregating concrete to form a filling structure in the box; The synthetic water-stopping structure and the box-filling structure are integrated to construct the structure. The method for constructing an underwater structure according to claim 2.

4. After forming the synthetic water-stopping structure, the water stored in the submerged portion of the box is completely drained to form a void portion in the box; Pouring a construction material that can be used in air into the void inside the box to construct the structure. The method for constructing an underwater structure according to claim 2.

5. The sheet pile member has at least one of a stud and a groove formed on the surface on which the laminated wall is provided. A method for constructing an underwater structure according to any one of claims 2 to 4.

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