Structure of offshore structure and construction method

Abstract

To ensure a secure connection between a superstructure and inclined piles, thereby suppressing horizontal displacement and reducing the number of piles, etc.SOLUTION: The present invention relates to structure of an offshore structure comprising a pile section driven into the seabed with a pile head located near the sea surface, and a superstructure mounted on the pile section. The pile section is configured with pipe axes of a plurality of steel pipe piles each inclined with respect to a vertical line. The superstructure is configured by connecting a plurality of precast slabs mounted on the respective pile heads of the plurality of steel pipe piles. Storage holes are formed in the plurality of precast slabs to store the pile heads of the plurality of steel pipe piles. The storage holes are formed parallel to the pipe axes of the steel pipe piles to be stored, and inclined with respect to the vertical line. Connecting surfaces of the plurality of adjacent precast slabs overlap vertically, inclined with respect to the vertical line. The inclination of the connecting surfaces is parallel to the inclination of the pipe axes of the steel pipe piles stored in the precast slab that overlaps on top.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to the structure of a marine structure and a method for constructing the same.

Background Art

[0002] When constructing marine structures such as piers and dolphins, piles erected on the seabed (submarine) may be used as a foundation. Such marine structures generally include a plurality of piles driven into the seabed ground and an upper structure made of concrete supported by the piles. Conventionally, straight piles (vertical piles) have been used as piles, and when precasting the upper structure, it has been known to use a double pipe method for the connection structure between the upper structure and the straight pile.

[0003] In the construction of marine structures such as piers and dolphins, inclined piles may be used instead of vertical piles due to factors such as suppression of horizontal displacement, reduction in the number of piles, and terrain. Also, as a concrete member for the upper structure, instead of cast-in-place concrete, for example, a member prefabricated in advance at a factory or the like, so-called precast concrete member, is known to be used.

[0004] For example, Patent Document 1 discloses a structure in which a precast member is joined to the pile head of an inclined pile via a joining member in a pile-supported structure such as a dolphin or a pier. Also, for example, Patent Document 2 discloses a construction method for a marine structure, and a technique has been proposed in which a precast member is installed on the head of an inclined pile erected on the seabed using a temporary scaffold.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in Patent Document 1 mentioned above, in the joining of the batter pile and the precast member, a structure is adopted in which a joining member is interposed. The protruding portion of the joining member is inserted and fixed along the vertical direction with respect to the insertion portion that opens on the lower surface of the precast member, and the same mechanism as that of the vertical pile is adopted. Therefore, the connection structure becomes somewhat complicated, such as using a joining member, and further efficiency improvement is required.

[0007] Also, in Patent Document 2 mentioned above, although a construction method using a temporary scaffold that can be easily installed and removed is disclosed, a known method is used for the joining method between the head of the batter pile and the precast member, and further efficiency improvement is required.

[0008] In addition, in both Patent Documents 1 and 2, a plurality of batter piles are inserted and joined to one precast member. However, when enlarging a marine structure such as a pier or a dolphin, it is required to combine a plurality of precast members, and a structure and a construction method adapted to such a mode are required.

[0009] In view of the above circumstances, an object of the present invention is to surely connect the superstructure and the batter piles in the construction of a marine structure provided with a superstructure composed of connecting a plurality of precast slabs to each other, and to provide a marine structure and a construction method thereof capable of suppressing horizontal displacement and reducing the number of piles.

Means for Solving the Problems

[0010] In order to achieve the above object, according to the present invention, there is provided a structure of an offshore structure composed of a pile portion driven into the seabed with a pile head portion positioned near the sea surface and an upper structure mounted on the pile portion, wherein the pile portion is configured such that the pipe axes of a plurality of steel pipe piles are each inclined with respect to the vertical line, the upper structure is configured by connecting a plurality of precast slabs each mounted on the pile heads of the plurality of steel pipe piles to each other, the plurality of precast slabs are each formed with a storage hole for storing the pile head of each of the plurality of steel pipe piles, the storage hole is parallel to the pipe axis of the steel pipe pile to be stored and is formed inclined with respect to the vertical line, the connecting surfaces of the plurality of adjacent precast slabs overlap vertically while being inclined with respect to the vertical line, and the inclination of the connecting surface and the inclination of the pipe axis of the steel pipe pile stored in the precast slab on the overlapping side on the upper side are configured to be parallel.

[0011] The pile portion may be composed of four steel pipe piles so as to form the hypotenuse of a square frustum, and the upper structure may be configured by connecting four precast slabs to each other.

[0012] Each of the plurality of adjacent precast slabs may be provided with a sleeve opening on the connecting surface, and the plurality of adjacent precast slabs may be connected to each other by slide reinforcing bars installed across the opposing sleeves and a time-dependent hardening material filled in the gap between the opposing connecting surfaces and in the sleeve.

[0013] According to the present invention, there is also provided a construction method of the structure of the offshore structure described above, including a pile foundation construction step of driving the four steel pipe piles into the seabed, a mounting step of sequentially mounting the four precast slabs on the pile heads of the four steel pipe piles, and a connecting step of connecting the four precast slabs to construct the superstructure. In the mounting step, the connecting surface of the precast slab mounted first is inclined upward, and the connecting surface of the precast slab mounted later is inclined downward. The precast slab mounted later is suspended in an oblique direction parallel to its connecting surface, and the pile head of the steel pipe pile is inserted into the storage hole, and the opposing connecting surfaces are overlapped vertically.

[0014] When the four precast slabs are called the first precast slab in the upper left, the second precast slab in the upper right, the third precast slab in the lower left, and the fourth precast slab in the lower right in a top view, in the mounting step, the first precast slab, the second precast slab, the third precast slab, and the fourth precast slab may be mounted in this order.

Effect of the Invention

[0015] According to the present invention, in the construction of an offshore structure provided with a superstructure composed of a plurality of precast slabs connected to each other, the connection between the superstructure and the batter piles can be surely made, and suppression of horizontal displacement, reduction of the number of piles, etc. can be achieved.

[0016] Note that the above effects are not necessarily limited, and together with the above effects, or instead of the above effects, any of the effects shown in this specification, or other effects that can be grasped from this specification may be achieved.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification and the drawings, components having substantially the same functional configuration may be denoted by the same reference numerals, and redundant description may be omitted. In this specification and the drawings, for the purpose of explanation, a part of a member may be omitted from illustration, or the internal configuration of a member may be illustrated and described.

[0019] The structure of the marine structure according to the present invention is a structure of a marine structure composed of a pile portion in which the pile head portion is driven into the seabed and is located near the sea surface, and an upper structure mounted on the pile portion. The pile portion is configured such that the pipe axes of a plurality of steel pipe piles are each inclined with respect to the vertical line, and the upper structure is configured by connecting a plurality of precast slabs respectively mounted on the pile heads of the plurality of steel pipe piles to each other. A storage hole for storing each pile head of the plurality of steel pipe piles is formed in the plurality of precast slabs. The storage hole is parallel to the pipe axis of the steel pipe pile to be stored and is formed inclined with respect to the vertical line. And, the connecting surfaces of a plurality of adjacent precast slabs overlap vertically while being inclined with respect to the vertical line, and are configured such that the inclination of the connecting surface is parallel to the inclination of the pipe axis of the steel pipe pile stored in the precast slab on the overlapping side on the upper side. In such a structure of the marine structure according to the present invention, the number of precast slabs and the number of corresponding steel pipe piles are arbitrary. Hereinafter, as an example of an embodiment of the present invention, the case where there are two precast slabs will be described as the first embodiment, and the case where there are four precast slabs will be described as the second embodiment.

[0020] <Structure of the marine structure according to the first embodiment> FIG. 1 is a schematic plan view of a structure 1 of a marine structure according to the first embodiment of the present invention. Further, FIG. 2 is a schematic side view of the structure 1 of the marine structure. Note that the structure 1 of the marine structure is usually installed on the seabed and in the sea as a marine structure such as a jetty or a dolphin, but here, for simplicity, the seabed, the sea surface, etc. are not shown.

[0021] As shown in FIGS. 1 and 2, the structure 1 includes two adjacent precast slabs 10 (10a, 10b) and steel pipe piles 20 (20a, 20b) inserted into the respective precast slabs 10a, 10b. Here, the steel pipe piles 20 (20a, 20b) are so-called inclined piles in which the pipe axes are inclined with respect to the vertical line.

[0022] Further, the upper structure 15 is formed by connecting and integrating two precast slabs 10a and 10b, and the upper structure 15 is mounted on the upper end portions (pile heads) of the pile portion 24 composed of two steel pipe piles 20a and 20b to form the structure 1. Although the sea surface and the seabed are not shown here, the steel pipe piles 20 are driven into the seabed so that the upper end portions of the pile portion 24 are located near the sea surface.

[0023] As shown in FIG. 2, in two adjacent precast slabs 10a and 10b, the connecting surfaces 11 (11a, 11b) located opposite to each other are formed to be inclined with respect to the vertical line. These connecting surfaces 11a and 11b are configured to overlap vertically when connected.

[0024] In the precast slab 10 (10a, 10b), storage holes 30 (30a, 30b) for storing the corresponding steel pipe piles 20 (20a, 20b) are formed at approximately the center thereof. The storage holes 30 are parallel to the pipe axes of the steel pipe piles 20 to be stored and are formed to be inclined with respect to the vertical line. For example, the storage hole 30a is formed to be parallel to the pipe axis P1 of the steel pipe pile 20a to be stored, and the storage hole 30b is formed to be parallel to the pipe axis P2 of the steel pipe pile 20b to be stored.

[0025] A plate member 32 for locking the steel pipe piles 20a and 20b in the storage holes 30a and 30b may be provided inside the storage holes 30a and 30b. The configuration of the plate member 32 is arbitrary, and for example, it may be a member horizontally fixed to the inner peripheral surface of the storage hole 30.

[0026] In the state where the precast slabs 10a and 10b are connected, the inclination of the connecting surface 11b of the upper precast slab 10b is configured to be parallel to the pipe axis P2 of the steel pipe pile 20b stored in the storage hole 30b of the precast slab 10b. Naturally, the inclination of the connecting surface 11a facing this connecting surface 11b is also in the same direction.

[0027] <Configuration of the connecting surface> FIG. 3 is a schematic cross-sectional view of the connecting surfaces 11 (11a, 11b) positioned to face each other in the precast slabs 10 (10a, 10b) described above, with the vicinity of the connecting surface 11 enlarged and shown.

[0028] As shown in FIG. 3, the precast slabs 10a, 10b are provided with sleeves 40 (40a, 40b) that open at the connecting surfaces 11a, 11b. When connecting the precast slabs 10a and 10b, the opposing sleeves 40a and 40b are configured to face each other. At the time of connection, a slide reinforcement 42 is installed across the two sleeves 40a and 40b, and a time-dependent hardening material (not shown) such as mortar or grout is filled inside the sleeves 40a, 40b and in the gap between the connecting surfaces 11a and 11b.

[0029] Also, a joint member 45 made of casting may be arranged inside the sleeve 40 (40a, 40b), and the slide reinforcement 42 may be accommodated inside this joint member 45. The construction method of the slide reinforcement 42 is arbitrary. For example, the slide reinforcement 42 is stored in the sleeve 40a and provided with a lid (not shown) for preventing it from popping out. When connecting the precast slabs 10a and 10b, the lid is removed and it may be pushed out by a spring (not shown) previously installed in the sleeve 40a. Also, a rope (not shown) may be tied to the slide reinforcement 42, and the slide reinforcement 42 may be pulled out by operating the rope. Also, internal reinforcements 47 may be provided so as to protrude from the inside of the precast slabs 10a, 10b into the sleeves 40a, 40b. When connecting the precast slabs 10a and 10b, the time-dependent hardening material is filled so as to enclose these slide reinforcements 42, joint members 45, and internal reinforcements 47 (a part thereof), and reliable connection is achieved by hardening.

[0030] <Construction Method of the Structure of the Offshore Structure According to the First Embodiment> Next, a method for constructing Structure 1 according to this embodiment will be described. FIG. 4 is a schematic explanatory diagram of the method for constructing Structure 1 according to this embodiment, and is illustrated assuming that the construction method proceeds in the order of (a) to (c).

[0031] First, as shown in FIG. 4(a), a pile foundation construction step of driving steel pipe piles 20 (20a, 20b) into the seabed G is performed. Both of the steel pipe piles 20a and 20b to be driven are inclined piles, and the pipe axes of the respective steel pipe piles 20a and 20b are inclined in predetermined directions.

[0032] Next, as shown in FIG. 4(b), a mounting step of mounting precast slabs 10 (10a, 10b) on the pile heads of the steel pipe piles 20 (20a, 20b) is performed. In the mounting step, the precast slabs 10a and 10b are sequentially mounted on the pile heads of the respective steel pipe piles 20a and 20b. The order at that time is as follows. The precast slab 10a having a connecting surface 11a inclined upward is first mounted on the pile head of the steel pipe pile 20a, and then the precast slab 10b having a connecting surface 11b inclined downward is mounted on the pile head of the steel pipe pile 20b.

[0033] When mounting the precast slab 10a to be mounted first, the construction is performed by suspending the pile head of the steel pipe pile 20a so as to be stored in the storage hole 30a. When mounting the precast slab 10b to be mounted later, the precast slab 10b is suspended in an oblique direction parallel to its connecting surface 11b, the pile head of the steel pipe pile 20b is inserted into the storage hole 30b, and the construction is performed so that the facing connecting surfaces 11a and 11b are overlapped vertically. In the mounting step, the precast slabs 10 (10a, 10b) may be constructed by a crane (not shown) via a wire W as shown in the figure.

[0034] In the mounting step, after inserting the pile heads of the steel pipe piles 20 (20a, 20b) into the storage holes 30 (30a, 30b), a time-dependent hardening material such as mortar or grout may be filled into the storage holes 30 (30a, 30b) in a state of being locked to the plate member 32.

[0035] Next, as shown in FIG. 4(c), with the opposing connecting surfaces 11a and 11b overlapping, a slide reinforcing bar 42 is accommodated inside across the sleeves 40a and 40b as described above with reference to FIG. 3. A time-dependent hardening material is filled in the gaps between the insides of the sleeves 40a and 40b and between the connecting surfaces 11a and 11b and hardened to connect the precast slabs 10a and 10b. By this connecting process, the precast slabs 10a and 10b are connected and the superstructure 15 is constructed.

[0036] Through the above pile foundation construction process, mounting process, and connecting process, the structure 1 of the marine structure with the superstructure 15 located near the sea surface is constructed.

[0037] <Structure of Marine Structure According to Second Embodiment> FIG. 5 is a schematic plan view of the structure 1a of the marine structure according to the second embodiment of the present invention. FIG. 6 is a schematic side view of the structure 1b of the marine structure. Similar to the first embodiment, for simplicity, the seabed, sea surface, etc. are not shown here. Also, in the following description, components having the same functional configuration as those in the first embodiment may be denoted by the same reference numerals and their description may be omitted.

[0038] As shown in FIG. 5, the structure 1a includes a superstructure 15 formed by connecting four precast slabs 50 (50a, 50b, 50c, 50d) to each other. Hereinafter, for the sake of explanation, the four precast slabs constituting the superstructure 15 may be referred to as the first precast slab 50a in the upper left, the second precast slab 50b in the upper right, the third precast slab 50c in the lower left, and the fourth precast slab 50d in the lower right in a top view.

[0039] In addition, the structure 1a includes steel pipe piles 60 (60a to 60d) inserted into the respective precast slabs 50a to 50d. Here, the steel pipe piles 60 (60a to 60d) are so-called inclined piles whose pile axes are inclined with respect to the vertical line. These four steel pipe piles 60a to 60d are configured to form the hypotenuses of a so-called frustum of a square pyramid. That is, the four steel pipe piles 60a to 60d are provided such that the distance between the steel pipe piles widens from top to bottom (see the arrows in Fig. 5).

[0040] The upper structure 15 is formed by connecting and integrating the four precast slabs 50a to 50d, and the structure 1a is formed by mounting the upper structure 15 on the upper ends (pile heads) of the pile part 24 composed of the four steel pipe piles 60a to 60d. Although the sea surface and the seabed are not shown here, the steel pipe piles 60 are driven into the seabed such that the upper ends of the pile part 24 are located near the sea surface.

[0041] Also, as shown in Figs. 5 and 6, in each of the adjacent precast slabs 50a and 50b, 50b and 50c, 50c and 50d, 50d and 50a, the connecting surfaces 51 (51a, 51b), 52 (52a, 52b), 53 (53a, 53b), 54 (54a, 54b) located opposite to each other are formed to be inclined with respect to the vertical line. These connecting surfaces 51 (51a, 51b), 52 (52a, 52b), 53 (53a, 53b), 54 (54a, 54b) are configured to overlap vertically when connected.

[0042] In the precast slabs 50 (50a, 50b, 50c, 50d), storage holes 70 (70a to 70d) for storing the corresponding steel pipe piles 60 (60a to 60d) are formed at approximately the center thereof. The storage holes 70 are parallel to the pipe axes of the respective steel pipe piles 60 to be stored and are formed to be inclined with respect to the vertical line. For example, the storage hole 70a is formed to be parallel to the pipe axis P1 of the steel pipe pile 60a to be stored, the storage hole 70b is formed to be parallel to the pipe axis P2 of the steel pipe pile 60b to be stored, the storage hole 70c is formed to be parallel to the pipe axis P3 of the steel pipe pile 60c to be stored, and the storage hole 70d is formed to be parallel to the pipe axis P4 of the steel pipe pile 60d to be stored. Note that plate members 32 similar to those in the first embodiment may be provided in the storage holes 70 (70a to 70d).

[0043] In a state where the precast slabs 50a, 50b, 50c, and 50d are connected to each other, the inclination of the connecting surface of the upper precast slab among the adjacent precast slabs is configured to be parallel to the pipe axis of the steel pipe pile stored in the storage hole of the precast slab. For example, in the connection between the precast slabs 50a and 50b, when the upper precast slab is the precast slab 50b, the inclination of the connecting surface 51b is configured to be parallel to the pipe axis P2 of the steel pipe pile 60b stored in the storage hole 70b. At this time, the inclination of the connecting surface 51a facing the connecting surface 51b is also in the same direction. Such a configuration is the same in the connection states of the precast slabs 50b and 50d, 50c and 50d, and 50a and 50c.

[0044] Note that in the structure 1a according to the present embodiment, the connection modes at the connecting surfaces 51 (51a, 51b), 52 (52a, 52b), 53 (53a, 53b), and 54 (54a, 54b) positioned to face each other are the same as those described with reference to FIG. 3 in the first embodiment.

[0045] <Construction Method of Structure of Offshore Structure According to Second Embodiment> Next, a method for constructing the structure 1a according to the present embodiment will be described. FIG. 7 is a schematic explanatory diagram of the method for constructing the structure 1a according to the present embodiment, where (a) shows the state before construction and (b) shows the state after construction. Here, since the basic construction methods such as the pile foundation construction process, the mounting process, and the connecting process are the same as those in the first embodiment (see FIG. 4), the description thereof will be omitted, and the construction order of the four precast slabs 50a to 50d will be described. Note that the numbers attached to the centers of the precast slabs in the figure indicate the construction order.

[0046] When constructing the upper structure 15 by combining a plurality of precast slabs (here, 50a to 50d), the connecting surface of the precast slab mounted first is designed to be inclined upward, and the connecting surface of the precast slab to be mounted later is designed to be inclined downward. Specifically, as shown in FIG. 7(a), when the first precast slab 50a in the upper left, the second precast slab 50b in the upper right, the third precast slab 50c in the lower left, and the fourth precast slab 50d in the lower right are mounted and connected in this order, between the first precast slab 50a and the second precast slab 50b, the connecting surface 51a is inclined upward, the connecting surface 51b is inclined downward, and the connecting surface 51b is overlapped on the upper side of the connecting surface 51a for connection. Similarly, between the second precast slab 50b and the fourth precast slab 50d, the connecting surface 52a is inclined upward, the connecting surface 52b is inclined downward, and the connecting surface 52b is overlapped on the upper side of the connecting surface 52a for connection. Similarly, between the third precast slab 50c and the fourth precast slab 50d, the connecting surface 53a is inclined upward, the connecting surface 53b is inclined downward, and the connecting surface 53b is overlapped on the upper side of the connecting surface 53a for connection. Similarly, between the first precast slab 50a and the third precast slab 50c, the connecting surface 54a is inclined upward, the connecting surface 54b is inclined downward, and the connecting surface 54b is overlapped on the upper side of the connecting surface 54a for connection.

[0047] In the connection of the precast slabs 50a to 50d, the upper structure 15 is constructed by being mounted in the order shown in FIG. 7. At this time, the precast slab to be mounted later is suspended in an oblique direction parallel to the connection surface, and the pile head of the steel pipe pile is inserted into the storage hole, and the opposing connection surfaces are overlapped vertically to perform the connection. For example, when connecting the first precast slab 50a and the second precast slab 50b, the second precast slab 50b is suspended in an oblique direction parallel to the connection surface 51b, and the pile head of the steel pipe pile 60b is inserted into the storage hole 70b formed therein. At the same time, the connection surface 51b is overlapped on the upper side of the connection surface 51a to perform the connection. The same applies to the connection between the second precast slab 50b and the fourth precast slab 50d, the connection between the third precast slab 50c and the fourth precast slab 50d, and the connection between the first precast slab 50a and the third precast slab 50c.

[0048] In this way, as shown in FIG. 7(b), the first precast slab 50a to the fourth precast slab 50d are connected, and the upper structure 15 in which these precast slabs 50a to 50d are connected to each other is mounted on the upper end of the pile portion 24 (not shown), and the structure 1a is constructed.

[0049] <Operational Effects of the Present Embodiment> According to the structure of the offshore structure and its construction method according to the present embodiment described above, a plurality of precast slabs are connected to each other to form the upper structure 15. Further, when mounting the upper structure 15 on the upper end of the pile portion 24, the pile head of the inclined pile (steel pipe pile) corresponding to each of the plurality of precast slabs constituting the upper structure 15 is inserted into the storage hole formed in each precast slab to perform the construction. Thereby, the connection between the upper structure and the inclined pile is surely performed, and suppression of horizontal displacement, reduction of the number of piles, etc. can be achieved.

[0050] In addition, by adopting such a construction method, precast of members progresses in the structure of offshore structures such as piers and dolphins, and constructability, member transportability, etc. can be improved, and productivity can be improved.

[0051] As described above, an example of an embodiment of the present invention has been explained, but the present invention is not limited to the illustrated form. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope of the idea described in the claims, and it is naturally understood that those also belong to the technical scope of the present invention.

[0052] In addition, the effects described in this specification are merely illustrative or exemplary and not restrictive. That is, the technology according to the present disclosure can exhibit other effects that are obvious to those skilled in the art from the description of this specification, together with or instead of the above effects.

[0053] <Modification Examples of the Present Invention> Hereinafter, modification examples of the present invention will be described. Here, components having the same functional configuration as those in the above embodiment may be given the same reference numerals and their description may be omitted.

[0054] FIG. 8 is a schematic explanatory diagram of a modification example of the present invention. When aiming for a larger structure as the structure of the offshore structure, a plurality of the structures 1 described in the first embodiment may be combined and connected to enlarge the entire offshore structure. As shown in FIG. 8, a plurality (here, three) of the structures 1 according to the first embodiment are constructed and connected to construct a large structure 100.

[0055] Also, in the second embodiment, when constructing the upper structure 15 by combining four precast slabs 50a to 50d, the first precast slab 50a in the upper left, the second precast slab 50b in the upper right, the third precast slab 50c in the lower left, and the fourth precast slab 50d in the lower right are used, and they are described as being loaded and connected in this order. However, the construction order is not limited to this.

[0056] For example, when constructing the upper structure 15 by combining four precast slabs 50a to 50d, in a top view, the first precast slab 50a can be placed in the upper left, the second precast slab 50b in the upper right, the third precast slab 50c in the lower right, and the fourth precast slab 50d in the lower left in a clockwise order. It is also acceptable to use this order for the construction sequence of loading and connecting them one by one.

[0057] Also, in a top view, the first precast slab 50a can be placed in the upper left, the second precast slab 50b in the lower right, the third precast slab 50c in the upper right, and the fourth precast slab 50d in the lower left. It is also acceptable to use this order for the construction sequence of loading and connecting them one by one.

Industrial Applicability

[0058] The present invention can be applied to the structure of a marine structure and its construction method.

Explanation of Reference Numerals

[0059] 1... Structure 10... Precast slab (of the first embodiment) 11... Connecting surface (in the first embodiment) 15... Upper structure 20... Steel pipe pile (of the first embodiment) 24... Pile part 30... Storage hole (of the first embodiment) 40... Sleeve 42... Slide reinforcing bar 50... Precast slab (of the second embodiment) 51 - 54... Connecting surface (in the second embodiment) 60... Steel pipe pile (of the second embodiment) 70... Storage hole (of the second embodiment) P1 - P4... Pipe axis (of the steel pipe pile) W... Wire

Claims

1. A structure of an offshore structure composed of a pile portion driven into the seabed with the pile head located near the sea surface and an upper structure mounted on the pile portion, wherein the pile portion is configured such that the pipe axes of a plurality of steel pipe piles are each inclined with respect to the vertical line, the upper structure is configured by connecting a plurality of precast slabs respectively mounted on the pile heads of the plurality of steel pipe piles to each other, the plurality of precast slabs are formed with storage holes for storing the respective pile heads of the plurality of steel pipe piles, the storage holes are parallel to the pipe axis of the steel pipe pile to be stored, and are formed inclined with respect to the vertical line, the connecting surfaces of the plurality of adjacent precast slabs overlap vertically while being inclined with respect to the vertical line, and are configured such that the inclination of the connecting surface is parallel to the inclination of the pipe axis of the steel pipe pile stored in the precast slab on the overlapping upper side. A structure of an offshore structure.

2. The pile portion is composed of four steel pipe piles so as to form the hypotenuse of a frustum of a square pyramid, The upper structure is configured by connecting four precast slabs to each other. The structure of the offshore structure according to Claim 1.

3. The plurality of adjacent precast slabs are each provided with a sleeve opening on the connecting surface, The plurality of adjacent precast slabs are connected to each other by slide reinforcing bars installed across the opposing sleeves and a time-dependent hardening material filled in the gap between the opposing connecting surfaces and in the sleeves. The structure of the offshore structure according to Claim 1 or 2.

4. A pile portion construction step of driving the four steel pipe piles into the seabed, A mounting step of sequentially mounting the four precast slabs on the pile heads of the four steel pipe piles, A connecting step of connecting the four precast slabs to each other to construct the upper structure, including: In the mounting step, the connecting surface of the precast slab mounted first is inclined upward, and the connecting surface of the precast slab mounted later is inclined downward, The precast slab mounted later is suspended in an oblique direction parallel to its connecting surface, the pile head of the steel pipe pile is inserted into the storage hole, and the opposing connecting surfaces are overlapped vertically. A construction method of the structure of the offshore structure according to Claim 2.

5. When the four precast slabs are called the first precast slab at the upper left, the second precast slab at the upper right, the third precast slab at the lower left, and the fourth precast slab at the lower right in a top view, In the mounting step, the first precast slab, the second precast slab, the third precast slab, and the fourth precast slab are mounted in this order. A method for constructing the structure of an offshore structure according to claim 4, characterized in that.

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