Jacket-type structure and method for constructing same

Abstract

To provide a jacket type structure having high flexibility in construction methods regardless of directions of steel pipe piles supporting a jacket and a construction method suitable for the jacket type structure.SOLUTION: A jacket type structure is provided with a plurality of piles 12 fixed on a ground 100 and a jacket 14 supported on the plurality of steel pipe piles 12. The jacket 14 comprises a body part 16 and a plurality of projected connection parts 18 arranged to project downward from the body part 16 and linearly connected to the plurality of steel pipe piles 12, respectively. At least a pair of the steel pipe pile 12 and the projected connection part 18 among a group of the steel pipe piles 12 and the projected connection parts 18 connected thereto are connected using a bridge steel member 20 bridging over an upper end surface of the steel pipe pile 12 and a lower end surface of the projected connection part 18.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a jacket-type structure and a method for constructing the same.

[0002] In this application, the term "jacket" is a general term for a framework structure mainly made of steel members, and a "jacket-type structure" is a structure that uses a jacket. [Background technology]

[0003] Standard construction methods for constructing jacket-type structures include the jacket-first method and the pile-first method, as described in, for example, Non-Patent Document 1, and Patent Document 1 describes an embodiment using the jacket-first method and an embodiment using the pile-first method.

[0004] The jacket-first method is a method of constructing a jacket-type structure by first driving some of the permanent steel pipe piles (hereinafter sometimes referred to as permanent piles) and / or temporary steel pipe piles (hereinafter sometimes referred to as temporary piles) before placing the jacket in its permanent location, and having the jacket supported by the previously driven permanent piles and / or temporary piles, and then driving the remaining permanent steel pipe piles in this state. If the permanent piles are not driven in advance and the jacket is supported only by the previously driven temporary piles, the jacket will be supported by the temporary piles and placed in its designated position, and then all of the permanent piles will be driven.

[0005] On the other hand, the pile-first method is a method in which after all the main piles have been driven in advance, a jacket is placed in the permanent location and fixed to the pre-driven main piles to construct a jacket-type structure.

[0006] When the longitudinal directions of all the steel pipe piles supporting the jacket are aligned in parallel, either the jacket-first method or the pile-first method can be used.

[0007] However, for example, if the longitudinal directions of the multiple steel pipe piles supporting the jacket are not all parallel, it is difficult to install the multiple steel pipe piles that have been pre-driven by covering each of the legs of the jacket. For this reason, in the current situation, there is no choice but to adopt the jacket-first method rather than the pile-first method, and it is not possible to pre-drive all of the multiple steel pipe piles that support the jacket, and depending on the situation at the site, it may be necessary to drive temporary piles. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2017-201101 A [Non-patent literature]

[0009] [Non-Patent Document 1] Coastal Development Technology Library No. 7, "Jacket Construction Method Technical Manual", Coastal Development Technology Research Center, January 2000 Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present invention is to provide a jacket-type structure that has a high degree of freedom in its construction method, regardless of the direction of the steel pipe piles supporting the jacket, and a construction method suitable for such a jacket-type structure. [Means for solving the problem]

[0011] The present invention has solved the above problems by providing the following jacket-type structure and a method for constructing the same.

[0012] In other words, the jacket-type structure of the present invention is a jacket-type structure comprising a plurality of steel pipe piles fixed to the ground and a jacket supported by the plurality of steel pipe piles, wherein the jacket has a main body and a plurality of protruding connecting portions which protrude downward from the main body and are connected in a linear manner to each of the plurality of steel pipe piles, and among the pairs of the steel pipe piles and the protruding connecting portions connected thereto, at least one pair of the steel pipe piles and the protruding connecting portions are connected using a bridging steel member which spans between the upper end surface of the steel pipe piles and the lower end surface of the protruding connecting portions.

[0013] In this application, the term "downward" includes not only a vertically downward direction but also an obliquely downward direction relative to the vertical direction.

[0014] In addition, the phrase "linearly connected" between the steel pipe pile and the protruding connecting portion means that the overall appearance of the connected state is generally linear, and "connected" includes not only a direct connection without using other members or materials, but also a connection via other members or materials. The same applies to other descriptions in this application.

[0015] The multiple protruding connection portions may include a first protruding connection portion protruding in a first downward direction from the main body portion, and a second protruding connection portion protruding in a second downward direction different from the first downward direction from the main body portion, and the connection using the bridge steel material may be made via either the first protruding connection portion or the second protruding connection portion.

[0016] In this application, the term "downward" includes not only a vertically downward direction but also a diagonally downward direction relative to the vertical direction.

[0017] The first protruding connection portion may protrude vertically downward from the main body portion, and the second protruding connection portion may protrude diagonally downward from the main body portion, and the connection using the bridge steel material may be made at the second protruding connection portion.

[0018] The first protruding connecting portion may be a leg, and the steel pipe pile may be inserted into and connected to the leg.

[0019] In this application, the leg of the jacket refers to a steel pipe member that protrudes downward or obliquely downward from the main body of the jacket, and is the portion that is connected to the steel pipe pile.

[0020] The lower end of the protruding connection part, which is connected using the bridge steel material, may be provided with a guide member that protrudes further downward than the lower end surface of the protruding connection part, and the guide member may be configured to guide the lower end surface of the protruding connection part so that it faces the upper end surface of the steel pipe pile connected to the protruding connection part.

[0021] The protruding connection portion which is connected using the bridging steel material is a leg, the bridging steel material is inserted along the inner circumferential surfaces of the leg and the steel pipe pile connected to the leg, and is arranged so as to bridge between the lower end surface of the leg and the upper end surface of the steel pipe pile, and further, the bridging steel material may be configured to be connected to the inner circumferential surface of the leg and the inner circumferential surface of the steel pipe pile.

[0022] Here, "inserting along the inner circumferential surface" includes not only the case where the insert is inserted without any gap from the inner circumferential surface, but also the case where the insert is inserted with a predetermined gap.

[0023] The bridge steel material may be a joint steel pipe that includes at least a portion of a cylindrical steel pipe as a component.

[0024] Such joint steel pipes can be, for example, integrally formed cylindrical steel pipes, but also specifically, for example, steel pipes divided in the circumferential direction (for example, divided into two or four parts) and formed into a cylindrical shape by connecting the parts by welding, mechanical joining, etc. Also, for reinforcement or connection, flanges or the like may be provided so as to protrude outward from the outer circumferential surface.

[0025] The configuration may be such that grout is filled between the outer peripheral surface of the joint steel pipe and the inner peripheral surfaces of the leg and the steel pipe pile.

[0026] The joint steel pipe may have a protrusion on its outer surface, and protrusions may be provided on the inner surface of the steel pipe pile into which the joint steel pipe is inserted and on the inner surface of the leg in an area where the grout is filled.

[0027] The joint steel pipe may be configured so that a plurality of radially protruding first spacers are provided at predetermined intervals circumferentially on the outer peripheral surface of the end portion on the steel pipe pile side, and a plurality of radially protruding second spacers are provided at predetermined intervals circumferentially on the outer peripheral surface of the end portion on the leg side.

[0028] The joint steel pipe may be configured so that a plurality of spacers are provided circumferentially spaced apart on its outer surface, protruding radially to a predetermined height along the axial direction of the joint steel pipe, and the plurality of spacers position the outer surface of the joint steel pipe at a predetermined distance from the inner surface of the leg and the inner surface of the steel pipe pile.

[0029] At least one of the plurality of first spacers and at least one of the plurality of second spacers may be configured to be integrally formed on the outer circumferential surface of the joint steel pipe in the axial direction of the joint steel pipe.

[0030] A cover member may be provided in the inner hollow portion of the steel pipe pile at a position below the lower end portion of the joint steel pipe arranged in the inner hollow portion.

[0031] The joint steel pipe may be configured so that a first connecting steel material is welded to the inner surface of the leg to be connected, and a second connecting steel material is welded to the inner surface of the end of the joint steel pipe on the leg side, the first connecting steel material and the second connecting steel material are connected, and the joint steel pipe is positioned on the inner surface of the leg via the first connecting steel material and the second connecting steel material.

[0032] The first connecting steel member and the second connecting steel member may be configured to be connected by on-site welding.

[0033] A cover member may be attached to the upper end of the leg connected to the steel pipe pile via the joint steel pipe.

[0034] The bridge steel material may be configured to be a joint steel pipe that surrounds a portion of the outer peripheral surfaces of the protruding connecting portion and the steel pipe pile that are connected using the bridge steel material, and is arranged to bridge between the lower end surface of the protruding connecting portion and the upper end surface of the steel pipe pile.

[0035] The bridge steel material may be a steel material having an inner peripheral surface whose shape matches the shape of the outer peripheral surface of the protruding connecting part to be connected and the shape of the outer peripheral surface of the steel pipe pile to be connected.

[0036] The configuration may be such that grout is filled between the inner peripheral surface of the joint steel pipe and the outer peripheral surfaces of the protruding connecting portion and the steel pipe pile.

[0037] At least one of the steel pipe piles may be an existing steel pipe pile.

[0038] In this application, the existing steel pipe pile refers to a steel pipe pile that was used in another structure that existed before the jacket-type structure according to the present invention was constructed.

[0039] A first aspect of the method for constructing a jacket-type structure according to the present invention is a method for constructing a jacket-type structure, comprising: a plurality of steel pipe piles fixed to the ground; and a jacket supported by the plurality of steel pipe piles, the jacket having a main body and a plurality of protruding connecting parts that are provided protruding downward from the main body and linearly connected to each of the plurality of steel pipe piles, and at least one pair of the steel pipe piles and the protruding connecting parts connected thereto is connected to each other using a bridging steel material that spans between an upper end surface of the steel pipe pile and a lower end surface of the protruding connecting part, the method comprising the steps of: fixing lower ends of the plurality of steel pipe piles to the ground; and upper ends of the plurality of steel pipe piles fixed to the ground in the fixing step. This method for constructing a jacket-type structure comprises: a jacket positioning process for positioning the jacket at a predetermined position so that the lower ends of the corresponding protruding connections are located in the vicinity of each other; a connecting process for attaching the bridging steel material to surround the outer peripheral surface of the lower end of at least one of the multiple protruding connections provided on the jacket positioned at the predetermined position in the jacket positioning process and the outer peripheral surface of the upper end of the steel pipe pile, thereby connecting the protruding connections to the steel pipe pile; and a grout filling process for filling grout between the outer peripheral surfaces of the lower ends of the protruding connections and the outer peripheral surface of the upper end of the steel pipe pile connected in the connecting process, and the bridging steel material surrounding these outer peripheral surfaces.

[0040] A second aspect of the method for constructing a jacket-type structure according to the present invention is a method for constructing a jacket-type structure comprising a plurality of steel pipe piles fixed to the ground and a jacket supported by the plurality of steel pipe piles, the jacket having a main body and a plurality of legs that are provided protruding downward from the main body and linearly connected to each of the plurality of steel pipe piles, at least one pair of the steel pipe pile and the leg connected thereto is connected to the steel pipe pile using a joint steel pipe that is inserted into the steel pipe pile and the leg so as to bridge and connect between an upper end surface of the steel pipe pile and a lower end surface of the leg, the method comprising the steps of: fixing lower ends of the plurality of steel pipe piles to the ground; and This method for constructing a jacket-type structure comprises: a jacket positioning process for positioning the jacket at a predetermined position so that the lower ends of the corresponding legs are each located near the upper ends of the multiple steel pipe piles fixed to the ground in the process; a positioning process for inserting the joint steel pipe into at least one of the multiple legs provided in the jacket positioned at the predetermined position in the jacket positioning process from above the leg and positioning it at a position where it spans between the upper end surface of the corresponding steel pipe pile and the lower end surface of the leg; and a grout filling process for filling grout between the outer surface of the joint steel pipe positioned in the positioning process and the inner surfaces of the steel pipe pile and the leg.

[0041] In a first aspect of the method for constructing a jacket-type structure according to the present invention, in the jacket positioning step, the jacket may be positioned so that the protruding connection portion and the steel pipe pile are in a straight line using a guide member that is provided at the lower end of the protruding connection portion, protruding further downward from the lower end surface of the protruding connection portion, and that abuts against the inner surface of the upper end of the corresponding steel pipe pile to guide it.

[0042] In a second aspect of the method for constructing a jacket-type structure according to the present invention, in the jacket positioning step, the jacket may be positioned so that the legs and the steel pipe piles are in a straight line using a guide member that is provided on the inner surface of the lower end of the leg, protruding further downward than the lower end surface of the leg, and that abuts against and guides the inner surface of the upper end of the corresponding steel pipe pile.

[0043] In a first aspect of the method for constructing a jacket-type structure according to the present invention, the multiple protruding connections provided on the jacket may include vertical protruding connections that protrude vertically downward and diagonal protruding connections that protrude diagonally downward, and in the jacket placement process, the upper end of the steel pipe pile fixed in the fixing process may be inserted into the vertical protruding connections.

[0044] In a second aspect of the method for constructing a jacket-type structure according to the present invention, the multiple legs provided in the jacket may include vertical legs protruding vertically downward and inclined legs protruding diagonally downward, and in the jacket placement process, the upper end of the steel pipe pile fixed in the fixing process may be inserted into the vertical leg.

[0045] In a second aspect of the method for constructing a jacket-type structure according to the present invention, the method may further include the steps of: after placing the joint steel pipe at a predetermined position in the inner hollow portion of the steel pipe pile and the inner hollow portion of the leg, attaching a first connecting steel material by welding to the inner surface of the leg so that it abuts the end face of the joint steel pipe on the leg side, and attaching a second connecting steel material by welding to the inner surface of the joint steel pipe and to the first connecting steel material by welding, thereby fixing the joint steel pipe to the inner surface of the leg via the first connecting steel material and the second connecting steel material. Effect of the Invention

[0046] According to the present invention, it is possible to provide a jacket-type structure having a high degree of freedom in construction method regardless of the direction of the steel pipe piles supporting the jacket, and a construction method suitable for such a jacket-type structure. [Brief description of the drawings]

[0047] [Figure 1] FIG. 1 is a perspective view showing a jacket-type structure 10 according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a side view showing the jacket-type structure 10 according to the first embodiment of the present invention (view taken in the direction of the arrow II in FIG. 1). [Diagram 3] FIG. 3 is an enlarged vertical cross-sectional view of part III in FIG. 2. [Figure 4] Cross-sectional view of line IV-IV in Figure 3 [Diagram 5] FIG. 11 is a vertical cross-sectional view showing the vertical downward movement of the inclined leg 18B when the upper end surface of the inclined steel pipe pile 12B and the lower end surface of the inclined leg 18B are brought into contact with each other. [Figure 6] Cross section of line VI-VI in Figure 3 [Figure 7] Cross-sectional view of line VII-VII in Figure 3 [Figure 8] 1 is a vertical cross-sectional view showing a typical process for constructing the jacket-type structure 10 according to the first embodiment; [Figure 9] FIG. 1 is a perspective view showing a typical process for constructing a jacket-type structure 10 according to a first embodiment; [Figure 10] 1 is a vertical cross-sectional view showing a typical process for constructing the jacket-type structure 10 according to the first embodiment; [Figure 11] FIG. 1 is a perspective view showing a typical process for constructing a jacket-type structure 10 according to a first embodiment; [Figure 12] FIG. 1 is a side view showing a typical process for constructing the jacket-type structure 10 according to the first embodiment; [Figure 13] FIG. 1 is a perspective view showing a typical process for constructing a jacket-type structure 10 according to a first embodiment; [Figure 14] FIG. 11 is an enlarged vertical cross-sectional view of a portion of a jacket-type structure 30 according to a second embodiment of the present invention, where a joint steel pipe 32 is provided. [Figure 15] Sectional view of line XV-XV in Figure 14 [Figure 16] Sectional view of line XVI-XVI in Figure 14 [Figure 17] FIG. 11 is an enlarged side view showing a portion of a jacket-type structure 40 according to a third embodiment of the present invention where a joint steel pipe 42 is provided. [Figure 18] FIG. 4 is a perspective view showing the joint steel pipe 42 before installation DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0049] (1) First embodiment (1-1) Configuration and Effects of the First Embodiment Fig. 1 is a perspective view showing a jacket-type structure 10 according to a first embodiment of the present invention, Fig. 2 is a side view (view taken in the direction of the arrow II in Fig. 1) showing the jacket-type structure 10 according to the first embodiment of the present invention, and Fig. 3 is an enlarged vertical sectional view showing part III in Fig. 2. The ground 100 is omitted in Fig. 1.

[0050] The jacket-type structure 10 is a structure that includes a plurality of steel pipe piles 12, a jacket 14, and a joint steel pipe 20, and is fixed to the ground 100 by the plurality of steel pipe piles 12, and is specifically suitable for use in, for example, a pier or a pier-type wharf. In the following description, the jacket-type structure 10 is assumed to be applied to a pier or a pier-type wharf, but the application of the jacket-type structure according to the present invention is not limited to piers or pier-type wharves, and can also be applied to breakwaters, bridge substructures, offshore facilities (dolphins, etc.), bottom-mounted foundations for offshore wind power generation facilities, substructures for offshore platforms for developing offshore oil and gas fields, and can also be applied to structures constructed on land.

[0051] The steel pipe pile 12 is a support pile that is driven into the ground 100 (see FIG. 2) vertically or at an angle to the vertical, and whose tip reaches a bearing layer with sufficient bearing capacity such as bedrock, and plays a role in maintaining the overall position of the jacket-type structure 10. If safety can be confirmed according to conditions such as the weight of the jacket-type structure 10 to be constructed, the steel pipe pile 12 may be a friction pile whose tip does not reach a bearing layer with sufficient bearing capacity such as bedrock. In addition, the steel pipe pile 12 may be a new steel pipe pile or an existing steel pipe pile. In addition, the steel pipe pile 12 is not limited to a configuration in which it is driven directly into the ground, but may be a configuration in which it is inserted into a steel pipe part of a fixing member having a steel pipe part fixed to bedrock and fixed to the bedrock, for example.

[0052] Of the steel pipe piles 12, the vertical steel pipe pile 12A is a steel pipe pile that is driven vertically into the ground 100, and the inclined steel pipe pile 12B is a steel pipe pile that is driven into the ground 100 at an angle to the vertical.

[0053] The jacket 14 is a steel structure constructed by assembling steel materials, and is composed of an upper steel girder portion 16 which is the upper portion, and legs 18 which are the lower portions.

[0054] The upper steel girder section 16 is the upper portion of the jacket 14 (sometimes referred to as the "main body" in this application), and is configured by arranging and assembling steel girders 16A vertically and horizontally to form a lattice shape, on which a deck (not shown) is placed. There are no particular limitations on the deck that can be placed, but specifically, for example, a concrete deck (precast deck, cast-in-place concrete deck, etc.) or a steel deck may be used.

[0055] The legs 18 are steel pipe members that protrude downward or diagonally downward from the upper steel girder portion 16, which is the main body of the jacket 14, and are connected to the steel pipe piles 12. Therefore, the legs 18 can also be called protruding connecting portions. The steel pipe piles 12 and the legs 18 are connected in a straight line, and the overall appearance of the connected piles is generally straight. Therefore, of the legs 18, the vertical leg 18A connected to the vertical steel pipe pile 12A has an axial direction that is vertical, and the inclined leg 18B connected to the inclined steel pipe pile 12B has an axial direction that is the same as the longitudinal direction of the inclined steel pipe pile 12B and is inclined with respect to the vertical direction.

[0056] Among the pairs of steel pipe piles 12 and legs 18 connected in a straight line, in the pair of the vertical steel pipe pile 12A and the vertical leg 18A connected in the vertical direction, the inner diameter of the vertical leg 18A is larger than the outer diameter of the vertical steel pipe pile 12A, and the vertical leg 18A is arranged so as to cover the upper end of the vertical steel pipe pile 12A. In the area where the vertical leg 18A covers the vertical steel pipe pile 12A, grout 22 is filled between the inner peripheral surface of the vertical leg 18A and the outer peripheral surface of the vertical steel pipe pile 12A, and the vertical leg 18A and the vertical steel pipe pile 12A are integrated.

[0057] In addition, among the pairs of steel pipe piles 12 and legs 18 connected in a straight line, in the pair of the inclined steel pipe pile 12B and the inclined leg 18B connected in a state inclined with respect to the vertical direction, the inner and outer diameters of the inclined steel pipe pile 12B and the inclined leg 18B are approximately the same, and the axial directions of the inclined steel pipe piles 12B and the inclined leg 18B are arranged in a state in which the end faces of the inclined steel pipe piles 12B and the inclined leg 18B are abutted against each other when the axial directions are aligned, so long as the end face of the inclined steel pipe pile 12B and the end face of the inclined leg 18B can abut against each other and the force can be sufficiently transmitted in the axial direction when the inclined steel pipe piles 12B and the inclined leg 18B are arranged in a straight line, the pipe thickness of the inclined steel pipe pile 12B and the pipe thickness of the inclined leg 18B do not necessarily have to be the same, the inner diameter of the inclined steel pipe pile 12B and the inner diameter of the inclined leg 18B do not necessarily have to be the same, and the outer diameter of the inclined steel pipe pile 12B and the outer diameter of the inclined leg 18B do not necessarily have to be the same.

[0058] In a set of inclined steel pipe piles 12B and inclined legs 18B that are connected in a straight line, the axial directions of each are aligned so that the end faces abut against each other, and there is no portion where one penetrates the other. Therefore, it is possible to lower the jacket 14 vertically from above, so that all the vertical legs 18A of the jacket 14 cover the corresponding vertical steel pipe piles 12A, and to position the jacket 14 so that the lower end faces of all the inclined legs 18B of the jacket 14 abut against the upper end faces of the corresponding inclined steel pipe piles 12B.

[0059] In a pair of inclined steel pipe pile 12B and inclined leg 18B that are connected in a straight line, as mentioned above, there is no portion where one penetrates the other, so in this application, the inclined steel pipe pile 12B may be referred to as a non-inserted steel pipe pile 12B, and the inclined leg 18B may be referred to as a non-inserted leg 18B.

[0060] In the inner hollow portion of the non-inserted steel pipe pile 12B and the non-inserted leg 18B, which are connected in a straight line, a joint steel pipe 20 is arranged to bridge between the upper end surface of the non-inserted steel pipe pile 12B and the lower end surface of the non-inserted leg 18B, and the joint steel pipe 20 can also be referred to as a bridging steel material.

[0061] The joint steel pipe 20 is a cylindrical steel pipe whose outer circumferential surface is arranged along the inner circumferential surface of the non-inserted steel pipe pile 12B and the inner circumferential surface of the non-inserted leg 18B, and the end on the lower end side is closed with a lid 20X. The lid 20X is a steel plate and is attached to the lower end of the joint steel pipe 20 by welding. The outer diameter of the joint steel pipe 20 is about 200 to 300 mm smaller than the inner diameter of the non-inserted steel pipe pile 12B and the inner diameter of the non-inserted leg 18B, and the distance between the outer circumferential surface of the joint steel pipe 20 and the inner circumferential surface of the non-inserted steel pipe pile 12B, and the distance between the outer circumferential surface of the joint steel pipe 20 and the inner circumferential surface of the non-inserted leg 18B are typically about 100 to 150 mm.

[0062] Furthermore, the cylindrical steel pipe that can be used as the joint steel pipe 20 may include at least a portion of a cylindrical steel pipe as a constituent element, as described above.

[0063] Between the outer peripheral surface of the joint steel pipe 20 and the inner peripheral surface of the non-inserted steel pipe pile 12B, and between the outer peripheral surface of the joint steel pipe 20 and the inner peripheral surface of the non-inserted leg 18B, grout 22 is filled and integrated. The type of grout 22 is not particularly limited, and for example, cement-based grout such as non-shrink mortar can be used. When filling the grout 22, as shown in FIG. 3, a seal material 24 is arranged so as to cover from the outside the upper end surface of the abutted non-inserted steel pipe pile 12B and the lower end surface of the non-inserted leg 18B, and the upper end and lower end are fixed with a steel band 24A. The material of the seal material 24 is not particularly limited, and for example, a rubber seal material can be used, and the fixing means is not limited to the steel band 24A, and other fixing means may be appropriately adopted. The seal material 24 and the steel band 24A may be removed after the grout 22 has hardened.

[0064] A protrusion functioning as a shear key may be provided on the outer peripheral surface of the joint steel pipe 20, and a protrusion functioning as a shear key may be provided on the inner peripheral surface of the non-inserted steel pipe pile 12B and the inner peripheral surface of the non-inserted leg 18B in the region where the grout 22 is filled, among the inner peripheral surface of the non-inserted steel pipe pile 12B and the inner peripheral surface of the non-inserted leg 18B. By providing a protrusion functioning as a shear key, the length of the region where the grout 22 is filled can be shortened, and the length of the joint steel pipe 20 used can be shortened.

[0065] The protrusion may be formed by rolling or welding. Specific examples of the protrusion formed by welding include a protrusion made of a weld bead formed by molten and solidified weld metal, and a protrusion formed by attaching a steel material having a rectangular or round cross-sectional shape by fillet welding.

[0066] In addition, concrete may be filled into the inner hollow portion of the joint steel pipe 20. By filling the inner hollow portion of the joint steel pipe 20 with concrete, the connection portion between the non-inserted steel pipe pile 12B and the non-inserted leg 18B can be reinforced.

[0067] As shown in Fig. 3, guide pieces 18B1 and 18B2 are attached to the inner peripheral surface of the lower end of the non-inserted leg 18B so as to protrude downward from the lower end of the non-inserted leg 18B. The guide pieces 18B1 and 18B2 are guide members that guide the position of the non-inserted leg 18B so that the lower end surface of the non-inserted leg 18B abuts against the upper end surface of the non-inserted steel pipe pile 12B.

[0068] Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3, and the cross section is drawn so that the lower position is at the bottom. As shown in Fig. 4, in the cross section taken along line IV-IV in Fig. 3, the height of guide piece 18B1 and the height of guide piece 18B2 are approximately the same. Note that the seal material 24 and the steel band 24A are omitted in Fig. 4.

[0069] 4, the guide pieces 18B1 and 18B2 provided at the lower end of the non-inserted leg 18B are provided at positions that divide the non-inserted leg 18B into eight equal parts in the circumferential direction. The guide pieces 18B1 are three guide members provided at a height position below the central axis of the non-inserted leg 18B, and the guide pieces 18B2 are five guide members provided at a height position above the central axis of the joint steel pipe 20 and at a height position equal to the central axis of the joint steel pipe 20.

[0070] As shown in Fig. 3, the guide piece 18B2 is a long and narrow plate-like member with a notched surface 18B2a at its lower end, and the notched surface 18B2a is a surface parallel to the vertical direction. Even when the upper end surface of the inclined steel pipe pile 12B and the lower end surface of the inclined leg 18B are brought into contact with each other, the jacket 14 is usually moved vertically downward, so that the inclined leg 18B is also moved vertically downward, as shown in Fig. 5 (a vertical cross-sectional view showing a schematic vertical downward movement of the inclined leg 18B when the upper end surface of the inclined steel pipe pile 12B and the lower end surface of the inclined leg 18B are brought into contact with each other). However, in order to allow the lower end of the guide piece 18B2 to smoothly enter the inner space of the inclined steel pipe pile 12B even during such downward movement, the notched surface 18B2a is a surface parallel to the vertical direction.

[0071] On the other hand, the guide pieces 18B1 are elongated plate-like members without a cutout surface as shown in FIG. 3, and are attached by welding to the inner peripheral surface of the lower end of the non-inserted leg 18B so that the width direction is the height direction as shown in FIG. 4. The guide pieces 18B1 are three guide members provided below the central axis of the non-inserted leg 18B, and have the role of preventing the inclined leg 18B from slipping off the upper end surface of the inclined steel pipe pile 12B with which it abuts. In order to make the surface of the guide pieces 18B1 (part of the surface is attached by welding to the inner peripheral surface of the lower end of the non-inserted leg 18B) follow the inner peripheral surface of the inclined steel pipe pile 12B, the guide pieces 18B1 do not have a cutout surface 18B2a like the guide pieces 18B2. However, the guide pieces 18B1 may have a shape similar to that of the guide pieces 18B2.

[0072] As shown in Fig. 3, front end spacers 20A and 20B are provided on the outer surface of the front end of the joint steel pipe 20, and rear end spacers 20C and 20D are provided on the outer surface of the rear end of the joint steel pipe 20. Here, the side in the forward direction (direction toward the non-inserted steel pipe pile 12B) when inserting the joint steel pipe 20 into the non-inserted steel pipe pile 12B and the non-inserted leg 18B is referred to as "front", and the side opposite to the forward direction is referred to as "rear". The same applies hereinafter to the joint steel pipe 20, the front end spacers 20A and 20B, and the rear end spacers 20C and 20D.

[0073] The front end spacers 20A, 20B provided on the outer surface of the front end of the joint steel pipe 20 and the rear end spacers 20C, 20D provided on the outer surface of the rear end of the joint steel pipe 20 are reduced in height toward the front end, as shown in Figure 3, allowing the joint steel pipe 20 to be smoothly inserted into the non-inserted steel pipe pile 12B and the non-inserted leg 18B.

[0074] The front end surfaces of the front end spacers 20A, 20B provided on the outer surface of the front end of the joint steel pipe 20 are flat surfaces perpendicular to the longitudinal direction of the joint steel pipe 20, and are adapted to abut against the pile inner cover 12B1 of the non-inserted steel pipe pile 12B. The pile inner cover 12B1 is attached by welding to the inner peripheral surface of the non-inserted steel pipe pile 12B so as to be perpendicular to the longitudinal direction of the non-inserted steel pipe pile 12B. The insertion depth of the joint steel pipe 20 into the non-inserted steel pipe pile 12B is determined by the attachment position of the pile inner cover 12B1.

[0075] Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 3, with the lower part of the cross section drawn downward. Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 3, with the lower part of the cross section drawn downward.

[0076] As shown in Fig. 6, the front end spacers 20A and 20B provided on the outer surface of the front end of the joint steel pipe 20 are provided at positions that divide the joint steel pipe 20 into eight equal parts in the circumferential direction. The front end spacers 20A are three spacers provided at a height position below the central axis of the joint steel pipe 20, and the front end spacers 20B are five spacers provided at a height position above the central axis of the joint steel pipe 20 and at a height position equal to the central axis of the joint steel pipe 20.

[0077] 6, the front end spacer 20A is taller than the front end spacer 20B and is in contact with the inner circumferential surface of the non-inserted steel pipe pile 12B. On the other hand, the front end spacer 20B is shorter than the front end spacer 20A and is not in contact with the inner circumferential surface of the non-inserted steel pipe pile 12B.

[0078] As shown in Fig. 7, the rear end spacers 20C and 20D provided on the outer surface of the rear end of the joint steel pipe 20 are provided at positions that divide the joint steel pipe 20 into eight equal parts in the circumferential direction. The rear end spacers 20C are three spacers provided at a height position below the central axis of the joint steel pipe 20, and the rear end spacers 20D are five spacers provided at a height position above the central axis of the joint steel pipe 20 and at a height position equal to the central axis of the joint steel pipe 20.

[0079] 7, the rear end spacer 20C is taller than the rear end spacer 20D and is in contact with the inner circumferential surface of the non-inserted leg 18B. On the other hand, the rear end spacer 20D is shorter than the rear end spacer 20C and is not in contact with the inner circumferential surface of the non-inserted leg 18B.

[0080] By providing the front end spacers 20A, 20B and the rear end spacers 20C, 20D, the distance between the inner peripheral surface of the non-inserted steel pipe pile 12B and the outer peripheral surface of the joint steel pipe 20 can be maintained at a predetermined distance, and the distance between the inner peripheral surface of the non-inserted leg 18B and the outer peripheral surface of the joint steel pipe 20 can be maintained at a predetermined distance. Therefore, the inner peripheral surface of the non-inserted steel pipe pile 12B and the outer peripheral surface of the joint steel pipe 20 can be prevented from directly contacting each other, and the inner peripheral surface of the non-inserted leg 18B and the outer peripheral surface of the joint steel pipe 20 can be prevented from directly contacting each other, so that the joint steel pipe 20 can be smoothly inserted into the non-inserted steel pipe pile 12B and the non-inserted leg 18B. Even if protrusions functioning as shear keys are provided on the outer peripheral surface of the joint steel pipe 20 and the inner peripheral surface of the non-inserted steel pipe pile 12B and the inner peripheral surface of the non-inserted leg 18B, the provision of the front end spacers 20A, 20B and the rear end spacers 20C, 20D allows the joint steel pipe 20 to be smoothly inserted into the non-inserted steel pipe pile 12B and the non-inserted leg 18B. Even if the non-inserted steel pipe pile 12B is an existing steel pipe pile that has been driven in for a long time and its cross section is deviated from a perfect circle, the joint steel pipe 20 can be smoothly inserted into the non-inserted steel pipe pile 12B and the non-inserted leg 18B.

[0081] In addition, the front end spacer 20A and the rear end spacer 20C may be replaced with spacers formed integrally and extending in the longitudinal direction of the joint steel pipe 20 (from the upper end to the lower end of the joint steel pipe 20), and the front end spacer 20B and the rear end spacer 20D may be replaced with spacers formed integrally and extending in the longitudinal direction of the joint steel pipe 20 (from the upper end to the lower end of the joint steel pipe 20).

[0082] (1-2) Construction procedure for constructing the jacket-type structure 10 according to the first embodiment The construction procedure for constructing the jacket-type structure 10 according to the first embodiment of the present invention will be explained step by step with reference to the drawings.

[0083] 8 to 13 are diagrams that diagrammatically show typical steps in constructing the jacketed structure 10 according to the first embodiment.

[0084] <Step S1> As shown in Fig. 8, all the steel pipe piles 12 (vertical steel pipe piles 12A and inclined steel pipe piles 12B) are driven into the ground 100 using a hydraulic hammer 102. After driving is completed, the pile inner lid 12B1 is attached to the inner circumferential surface of the inclined steel pipe pile 12B at a predetermined position by welding. When attaching the pile inner lid 12B1 by welding, welding is performed all around or at four or more positions. In addition, in preparation for filling with grout 22 in step S5, the gap between the inner circumferential surface of the inclined steel pipe pile 12B and the pile inner lid 12B1 is sealed with a sealant (not shown) as necessary.

[0085] <Step S2> In order to attach the jacket 14 to the steel pipe pile 12 driven in step S1, the jacket 14 is hoisted by a crane 104 as shown in Fig. 9. Guide pieces 18B1, 18B2 (see Figs. 3 and 4) are pre-attached to the lower ends of the legs 18 of the jacket 14 at predetermined positions by factory welding.

[0086] <Step S3> The jacket 14 hoisted by the crane 104 is lowered vertically so that the vertical leg 18A covers the upper end of the vertical steel pipe pile 12A and the lower end surface of the inclined leg (non-inserted leg) 18B abuts against the upper end surface of the inclined steel pipe pile (non-inserted steel pipe pile) 12B, and the jacket 14 is positioned as shown in Fig. 10. At this time, guide pieces 18B1 and 18B2 attached in advance to predetermined positions of the inclined leg 18B guide the inclined leg (non-inserted leg) 18B so that the lower end surface of the inclined leg (non-inserted leg) 18B abuts against the upper end surface of the inclined steel pipe pile (non-inserted steel pipe pile) 12B.

[0087] Furthermore, a temporary support bracket 18A1 is attached in advance by welding to a predetermined position on the inner peripheral surface of the vertical leg 18A so that the vertical leg 18A covers the upper end of the vertical steel pipe pile 12A by an appropriate length.

[0088] <Step S4> After arranging the jacket 14 in the arrangement state as shown in Fig. 10 in step S3, as shown in Fig. 11, the joint steel pipe 20 is lifted by the crane 104, and the joint steel pipe 20 is arranged at a predetermined position in the inner hollow of the inclined steel pipe pile 12B and the inclined leg 18B, and arranged so as to bridge between the upper end surface of the inclined steel pipe pile 12B and the lower end surface of the inclined leg 18B. When arranging the joint steel pipe 20 in the inner hollow of the inclined steel pipe pile 12B and the inclined leg 18B, as shown in Fig. 3, the front end surface of the front end spacer 20A, 20B provided on the outer surface of the front end of the joint steel pipe 20 is made to abut against the pile inner lid 12B1 of the non-inserted steel pipe pile 12B. Therefore, the insertion depth of the joint steel pipe 20 into the non-inserted steel pipe pile 12B is determined by the mounting position of the pile inner lid 12B1.

[0089] <Step S5> After placing the joint steel pipe 20 in step S4, a sealant 24 is provided to cover the upper end surface of the abutting inclined steel pipe pile 12B and the lower end surface of the inclined leg 18B from the outside, as shown in Fig. 12. Then, grout 22 is filled between the outer circumferential surface of the joint steel pipe 20 and the inner circumferential surface of the inclined steel pipe pile 12B, and between the outer circumferential surface of the joint steel pipe 20 and the inner circumferential surface of the inclined leg 18B, to integrate them.

[0090] In addition, a sealing material (not shown) is provided between the lower end of the vertical leg 18A and the outer peripheral surface of the vertical steel pipe pile 12A, and in the area where the vertical leg 18A covers the vertical steel pipe pile 12A, grout 22 is filled between the inner peripheral surface of the vertical leg 18A and the outer peripheral surface of the vertical steel pipe pile 12A to integrate the vertical leg 18A and the vertical steel pipe pile 12A.

[0091] When the grout 22 filled in step S5 hardens and the integration of the steel pipe pile 12 and the jacket 14 is completed, the jacketed structure 10 according to the first embodiment is completed.

[0092] <Step S6> In step S5, the jacket-type structure 10 according to the first embodiment is completed. However, when actually used, a deck section is usually provided above the upper steel girder section 16, which is the main body of the jacket 14. Therefore, as shown in FIG. 13, a top lid 18C is provided at the top opening of the leg 18 of the jacket 14 to close the top opening of the leg 18. Usually, the top lid 18C is a steel plate, and is attached to the leg 18 by welding so that the top surface of the top lid 18C is aligned with the top surface of the leg 18. Even if the use mode of the jacket-type structure 10 is a use mode in which a deck section is not provided above the upper steel girder section 16, it is preferable to provide the top lid 18C at the top opening of the leg 18 to close the top opening of the leg 18 in order to prevent moisture and corrosive substances from entering the inner space of the leg 18.

[0093] (2) Second embodiment Figure 14 is an enlarged vertical cross-sectional view showing a portion of a jacket-type structure 30 according to the second embodiment of the present invention in which a joint steel pipe 32 is provided, Figure 15 is a cross-sectional view taken along line XV-XV in Figure 14, and Figure 16 is a cross-sectional view taken along line XVI-XVI in Figure 14.

[0094] In the jacket-type structure 10 of the first embodiment, the connection between the inclined leg 18B and the joint steel pipe 20 was only via grout 22, but in the jacket-type structure 30 of the second embodiment, the rear end of the joint steel pipe 32 is connected to the inner surface of the inclined leg 18B by welding via the first connecting steel material 34 and the second connecting steel material 36, and the connection between the inclined leg 18B and the joint steel pipe 32 is achieved not only via grout 22, but also by welding via the first connecting steel material 34 and the second connecting steel material 36.

[0095] For this reason, the length of the joint steel pipe 32 in the jacket-type structure 30 according to the second embodiment is shorter than the length of the joint steel pipe 20 in the jacket-type structure 10 according to the first embodiment.

[0096] Other than these points, the jacket-type structure 30 of the second embodiment is similar to the jacket-type structure 10 of the first embodiment, so that corresponding components and parts are generally given the same symbols and descriptions are generally omitted.

[0097] 14 and 15, the first connecting steel material 34 includes three bracket steel plates 34A and one connection steel plate 34B, and the first connecting steel materials 34 are provided at positions that divide the inclined leg 18B into four equal parts in the circumferential direction, with four first connecting steel materials 34 provided for each inclined leg 18B. As shown in Fig. 14, the bracket steel plates 34A are pentagonal steel plates, and are welded (usually welded on site) to the inner peripheral surface of the inclined leg 18B so that the longest side is parallel to the axial direction of the inclined leg 18B, and one side on the lower end side of the bracket steel plate 34A is welded (usually welded in a factory or the like before being delivered to the site) in contact with the surface of the connection steel plate 34B. In addition, when welding the bracket steel plate 34A of the first connecting steel material 34 to the inner surface of the inclined leg 18B, it is preferable to position the first connecting steel material 34 so that the lower surface of the connecting steel plate 34B of the first connecting steel material 34 abuts the upper end surface of the joint steel pipe 32.

[0098] 14 and 16, the second connecting steel members 36 are rectangular steel plates, and are welded (usually on-site welded) to the inner peripheral surface of the joint steel pipe 32 so that their long sides are in the axial direction of the joint steel pipe 32, and their short sides abut and are welded (usually on-site welded) to the surface of the connecting steel plate 34B. The second connecting steel members 36 are provided below the first connecting steel members 34, and three second connecting steel members 36 are provided for one first connecting steel member 34.

[0099] As described above, in the jacket-type structure 30 of the second embodiment, the connection between the inclined leg 18B and the joint steel pipe 32 is achieved not only via the grout 22, but also by welding via the first connecting steel material 34 and the second connecting steel material 36. As a result, the length of the joint steel pipe 32 can be made shorter than the length of the joint steel pipe 20 of the jacket-type structure 10 of the first embodiment. Therefore, even if the distance from the lower end of the upper steel girder portion 16 of the jacket 14 to the water surface is short, it is easier to prevent the lower end of the inclined leg 18B from reaching the water surface than in the jacket-type structure 10 of the first embodiment, and underwater work can be reduced.

[0100] Furthermore, since the rear end of the joint steel pipe 32 is connected to the inner surface of the inclined leg 18B via the first connecting steel material 34 and the second connecting steel material 36, the first connecting steel material 34 and the second connecting steel material 36 also have the function of determining the positioning position of the joint steel pipe 32 within the inclined leg 18B.

[0101] (3) Third embodiment Figure 17 is an enlarged side view of a portion of a jacket-type structure 40 relating to the third embodiment of the present invention, in which a joint steel pipe 42 is provided, and Figure 18 is an oblique view showing the joint steel pipe 42 before installation.

[0102] In the jacket-type structure 10 according to the first embodiment, the inclined steel pipe pile (non-inserted steel pipe pile) 12B and the inclined leg (non-inserted leg) 18B are connected to each other via a joint steel pipe 20 arranged in the inner hollow portion of the inclined steel pipe pile 12B and the inner hollow portion of the inclined leg 18B so as to bridge between the upper end surface of the inclined steel pipe pile 12B and the lower end surface of the inclined leg 18B. In the jacket-type structure 30 according to the second embodiment, the inclined steel pipe pile 12B and the inclined leg 18B are connected to each other via a joint steel pipe 20 arranged in the inner hollow portion of the inclined steel pipe pile 12B and the lower end surface of the inclined leg 18B. In the jacket-type structure 40 according to the third embodiment of the present invention, the connection between the inclined steel pipe pile 12B and the inclined leg 18B is made via a joint steel pipe 32 arranged in the inner hollow of the inclined steel pipe pile 12B and the inner hollow of the inclined leg 18B so as to bridge between the upper end surface of the inclined steel pipe pile 12B and the lower end surface of the inclined leg 18B, but in the jacket-type structure 40 according to the third embodiment of the present invention, the connection between the inclined steel pipe pile 12B and the inclined leg 18B is made via a joint steel pipe 42 arranged along the outer circumferential surface of the inclined steel pipe pile 12B and the outer circumferential surface of the inclined leg 18B so as to bridge between the upper end surface of the inclined steel pipe pile 12B and the lower end surface of the inclined leg 18B. Other than this point and the configuration associated with this point, the jacket-type structure 40 according to the third embodiment is similar to the jacket-type structure 10 according to the first embodiment and the jacket-type structure 30 according to the second embodiment. Therefore, in explaining the jacket-type structure 40 of the third embodiment, in principle, only the joint steel pipe 42 and the configuration associated with the joint steel pipe 42 will be explained, and explanations of configurations other than the joint steel pipe 42 and the configuration associated with the joint steel pipe 42 will be replaced with explanations of the corresponding configurations of the jacket-type structure 10 of the first embodiment.

[0103] As shown in Figures 17 and 18, the joint steel pipe 42 has two semicircular joint steel pipes 44, and the semicircular joint steel pipe 44 has a semicircular steel pipe 44A, an axial end flange 44B, a circumferential end flange 44C, and a reinforcing rib 44D.

[0104] The semicircular steel pipe 44A is a steel pipe with an inner diameter 100 to 300 mm larger than the outer diameter of the inclined steel pipe pile 12B and the outer diameter of the inclined leg 18B, cut into two in the axial direction, and has a semicircular cross section. The inner peripheral surface of the semicircular steel pipe 44A is a shape that fits the shape of the outer peripheral surface of the inclined steel pipe pile 12B and the shape of the outer peripheral surface of the inclined leg 18B. As shown in FIG. 17, both axial ends of the semicircular steel pipe 44A are not cut perpendicular to the axial direction but cut at an angle so that the axial end flanges 44B of the semicircular joint steel pipe 44 arranged along the outer peripheral surfaces of the inclined steel pipe pile 12B and the inclined leg 18B are horizontal.

[0105] The axial end flanges 44B are flanges provided on both axial ends of the semicircular steel tube 44A, and are provided so as to protrude outward from the outer circumferential surface of the semicircular steel tube 44A, and serve to reinforce both axial ends of the semicircular steel tube 44A.

[0106] The circumferential end flanges 44C are flanges provided at both circumferential ends of the semicircular steel pipe 44A, and are provided so as to protrude outward from the outer circumferential surface of the semicircular steel pipe 44A. When arranging the joint steel pipe 42 along the outer circumferential surface of the inclined steel pipe pile (non-inserted steel pipe pile) 12B and the outer circumferential surface of the inclined leg (non-inserted leg) 18B, the flange surfaces of the circumferential end flanges 44C of the two semicircular joint steel pipes 44 are arranged so as to abut against each other, and a bolt 44C1 is arranged so as to pass through the two abutted circumferential end flanges 44C, and is tightened to connect them.

[0107] The reinforcing rib 44D is a reinforcing steel plate arranged between the outer peripheral surface of the semicircular steel tube 44A and the circumferential end flange 44C, and is a reinforcing steel plate connected to the semicircular steel tube 44A and the circumferential end flange 44C by welding.

[0108] 17, a stand 46 that supports the joint steel pipe 42 from below is attached by welding to the outer circumferential surface of the inclined steel pipe pile 12B when the joint steel pipe 42 is placed. A bracket 46A that supports the stand 46 from below is provided between the lower surface of the stand 46 and the outer circumferential surface of the inclined steel pipe pile 12B, and the bracket 46A is attached by welding to the lower surface of the stand 46 and the outer circumferential surface of the inclined steel pipe pile 12B. The lower end position of the joint steel pipe 42 is determined by the attachment position of the stand 46.

[0109] Two semicircular joint steel pipes 44 are placed on the upper surface of the frame 46, the circumferential end flanges 44C are abutted against each other, and bolts 44C1 are placed so as to pass through the abutting circumferential end flanges 44C and tightened to connect them. The joint steel pipe 42 is then assembled, and grout 22 is filled between the outer circumferential surface of the inclined steel pipe pile 12B and the inner circumferential surface of the joint steel pipe 42, and between the outer circumferential surface of the inclined leg 18B and the inner circumferential surface of the joint steel pipe 42, to integrate them.

[0110] The joint steel pipe 42 is arranged to bridge between the upper end surface of the inclined steel pipe pile 12B and the lower end surface of the inclined leg 18B, connecting the inclined steel pipe pile 12B and the inclined leg 18B, and the joint steel pipe 42 can also be referred to as a bridging steel material.

[0111] In the third embodiment, after the lower end face of the inclined leg (non-inserted leg) 18B is abutted against the upper end face of the inclined steel pipe pile (non-inserted steel pipe pile) 12B, the joint steel pipe 42 is attached to the inclined steel pipe pile 12B and the inclined leg 18B only from the outside of the inclined steel pipe pile 12B and the inclined leg 18B, so construction is easy. However, since the joint steel pipe 42 is attached from the outside of the inclined steel pipe pile 12B and the inclined leg 18B, the site condition in which the jacket-type structure 40 according to the third embodiment is suitable for application is when the distance from the lower end of the upper steel girder part 16 of the jacket 14 to the water surface is relatively long.

[0112] (4) Supplementary information In the jacket-type structures 10, 30, 40 according to the first to third embodiments described above, the description has been given on the assumption that the upper end surface of the inclined steel pipe pile (non-inserted steel pipe pile) 12B and the lower end surface of the inclined leg (non-inserted leg) 18B are in direct abutment with each other. However, it is not essential that the upper end surface of the inclined steel pipe pile 12B and the lower end surface of the inclined leg 18B are in direct abutment with each other. It is also possible to attach an abutment member between the upper end surface of the inclined steel pipe pile 12B and the lower end surface of the inclined leg 18B to connect the two, and to indirectly abut the upper end surface of the inclined steel pipe pile 12B and the lower end surface of the inclined leg 18B via the abutment member.

[0113] In addition, in the jacket-type structures 10, 30, 40 according to the first to third embodiments described above, joint steel pipes 20, 32, 42 are used as connecting members connecting the inclined steel pipe pile 12B and the inclined leg 18B, but the connecting members applicable to the present invention are not limited to those having a tubular shape, and for example, steel material having an H-shaped cross section can also be used as the connecting member.

[0114] In the jacket-type structures 10, 30, and 40 according to the first to third embodiments described above, the guide pieces 18B1 and 18B2 are attached to the inner peripheral surface of the lower end of the inclined leg 18B, but they may be attached to the outer peripheral surface of the lower end of the inclined leg 18B. In that case, however, the shapes of the guide pieces 18B1 and 18B2 are appropriately changed in accordance with the change in the attachment position to the outer peripheral surface of the lower end of the inclined leg 18B. [Explanation of symbols]

[0115] 10, 30, 40...Jacket type structure 12...Steel pipe pile 12A: Vertical steel pipe pile 12B: Inclined steel pipe pile (non-inserted steel pipe pile) 12B1…Pile inner cover 14…Jacket 16...Upper steel girder 16A…Steel girder 18…Leg 18A…Vertical leg 18A1…Temporary support bracket 18B…Sloped leg (non-inserted leg) 18B1, 18B2...Guide piece 18B2a…Notched surface 18C…Top lid 20, 32, 42... Steel pipe joints 20A, 20B...Front end spacer 20C, 20D...Rear end spacer 20X…Lid 22…Grout 24…Sealing material 24A…Steel band 34…First connecting steel material 34A…Bracket steel plate 34B…Connecting steel plate 36…Second connecting steel material 44...Semicircular joint steel pipe 44A…Semicircular steel pipe 44B…Axial end flange 44C...Circumferential end flange 44C1…Bolt 44D…Reinforcing rib 46…Frame 46A…Bracket 100...ground 102...Hydraulic hammer 104…Crane

Claims

1. A plurality of steel pipe piles fixed to the ground; A jacket supported by the plurality of steel pipe piles; A plurality of bridging members bridging between the steel pipe pile and the jacket; A jacket-type structure comprising: The jacket is A main body portion, A plurality of legs protruding downward from the main body portion and each of which is provided to connect to each of the plurality of steel pipe piles; having Each of the plurality of bridging members is a member that bridges between each of the plurality of legs and each of the plurality of corresponding steel pipe piles, and each of the plurality of bridging members is inserted along the inner circumferential surface of each of the plurality of steel pipe piles and the inner circumferential surfaces of each of the plurality of legs corresponding to each of the plurality of steel pipe piles so as to bridge between the upper end surface of each of the plurality of steel pipe piles and the lower end surface of each of the plurality of legs, Of the end faces on the leg side and the end faces on the steel pipe pile side of each of the plurality of bridging members, the end faces on the leg side abut against a member provided protruding inward at a predetermined position on the inner circumferential surface of the leg into which the bridging member is inserted, and the end faces on the steel pipe pile side abut against a member provided on the inside at a predetermined position on the inner circumferential surface of the steel pipe pile into which the bridging member is inserted, A jacket-type structure characterized in that grout is filled between the inner surfaces of the legs and the steel pipe piles and the outer surface of the inserted bridging member.

2. 2. The jacket-type structure according to claim 1, further comprising a guide member provided at the lower end of the leg into which the bridging member is inserted, the guide member protruding further downward from the lower end surface of the leg, and the guide member guides the lower end surface of the leg so that it faces the upper end surface of the steel pipe pile connected to the leg.

3. A jacket-type structure as described in claim 1 or 2, characterized in that a protrusion is provided on the outer surface of the bridging member, and protrusions are provided on the inner surface of the steel pipe pile into which the bridging member is inserted and on the inner surface of the leg in an area where the grout is filled.

4. A jacket-type structure as described in any of claims 1 to 3, characterized in that a plurality of radially protruding first spacers are provided at predetermined intervals in the circumferential direction on the outer peripheral surface of the end of the bridge member on the steel pipe pile side, and a plurality of radially protruding second spacers are provided at predetermined intervals in the circumferential direction on the outer peripheral surface of the end on the leg side.

5. A jacket-type structure as described in any one of claims 1 to 3, characterized in that the bridging member has a plurality of spacers spaced circumferentially on its outer surface, which protrude radially along the axial direction of the bridging member to a predetermined height, and the plurality of spacers position the outer surface of the bridging member at a predetermined distance from the inner surface of the leg and the inner surface of the steel pipe pile.

6. A jacket-type structure as described in any one of claims 1 to 5, characterized in that a first connecting steel material is welded to the inner surface of the leg as the member protruding inward at a predetermined position on the inner surface of the leg into which the bridging member is inserted, a second connecting steel material is welded to the inner surface of the bridging member as the end face of the bridging member on the leg side, and the bridging member is positioned within the leg by abutting the first connecting steel material and the second connecting steel material.

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