Construction methods for foundation structures, ring bodies, steel segments, and foundation structures.

Abstract

Regarding foundation structures, we will be able to accommodate large-diameter and deep construction. [Solution] The foundation structure (1) has a plate (41) that forms a wall surface, a joint portion (43) erected at the longitudinal end of the plate, and a main girder (42) erected at the short end of the plate, and a plurality of steel segments (40) arranged in a ring shape, and a connecting mechanism (50) that connects adjacent steel segments, and a segment structure (10) in which ring bodies (11, 12) are arranged radially outward and radially inward, and a plurality of each are arranged and connected in the axial direction, and a reinforcing member (30) is arranged between the radially outward ring body (11) and the radially inward ring body (12) along the axial direction of the segment structure, and a filling portion (20) is filled between the radially outward ring body and the radially inward ring body, and the segment structure has a plurality of shear reinforcing members (60) that connect the radially outward ring body and the radially inward ring body.

Description

Technical Field

[0001] The present invention relates to a foundation structure, an annular body, a steel segment, and a construction method of a foundation structure.

Background Art

[0002] In order to construct a foundation structure such as a shaft or a bridge pier reinforcement underground, a plurality of steel segments are connected to construct a ring body, and a foundation structure in which a plurality of ring bodies are connected in the axial direction thereof is constructed underground. A construction method is known. When constructing a foundation structure, a cutting edge ring is provided on the ground surface of the construction site, the ground inside the cutting edge ring is excavated, and then the upper end of the cutting edge ring is pressed toward the ground by a sinking device to sink the cutting edge ring underground. After the cutting edge ring is sunk to a certain depth, another ring body is connected to the upper end of the cutting edge ring, the inside of the ring body is excavated, and the upper end of the ring body is pressed toward the ground by a sinking device to sink the ring body underground. In this way, by repeating the connection of a plurality of ring bodies, the excavation of the ground, and the pressing of the ring body in order, a soil retaining wall made of steel segments can be constructed underground. Next, bottom concrete is placed on the shaft ground. Next, reinforcement bars (main reinforcement bars, stirrups) are provided inside the shaft surrounded by the soil retaining wall made of steel segments, and concrete is placed. When the placed concrete solidifies, a reinforced concrete foundation structure is completed.

[0003] Although the amount of steel used for the soil retaining wall formed by steel segments is enormous, the rigidity of the joint portion between adjacent steel segments is low. Therefore, it is treated as a temporary member in terms of strength design and is treated as non-existent after the completion of the foundation structure. Therefore, its use is limited considering the production and construction costs, and effective utilization of steel segments has been demanded. To meet this demand, by directly engaging the main reinforcement with the steel segment and integrating it with concrete, it became possible to use the steel segment as part of the foundation structure. Furthermore, by making the connection between the steel segments stronger than before, the ring-shaped body formed by connecting the steel segments can be considered as a stirrup, making it possible to use the segment structure as part of the foundation (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Patent No. 7138146 [Overview of the project] [Problems that the invention aims to solve]

[0005] There is a growing demand for foundation structures that can accommodate large-diameter and deep construction. The foundation structure described in Patent Document 1 increases in weight as the diameter and depth increase, as the amount of concrete poured inside also increases, and there is a risk that it will sink into the ground under its own weight. Therefore, there is a need for a foundation structure that can accommodate large-diameter and deep construction without significantly increasing the weight.

[0006] Therefore, the present invention has been made in view of the above-mentioned problems, and aims to provide a technology that can handle large-diameter and deep-depth construction of foundation structures. [Means for solving the problem]

[0007] One aspect of the present invention is a foundation structure comprising: a plate forming a wall surface; a joint portion erected at the longitudinal end of the plate; a main girder erected at the short end of the plate; a plurality of steel segments arranged in an annular shape; a connecting mechanism for connecting adjacent steel segments; a segment structure in which annular bodies are arranged radially outward and radially inward, and a plurality of annular bodies are arranged and connected in the axial direction; a reinforcing member positioned between the radially outward annular body and the radially inward annular body along the axial direction of the segment structure; and a filling portion filled between the radially outward annular body and the radially inward annular body, wherein the segment structure comprises a plurality of shear reinforcing members connecting the radially outward annular body and the radially inward annular body.

[0008] Furthermore, in one embodiment described above, the steel segment preferably comprises a plurality of ribs erected between the longitudinal ends of the plate, and the shear reinforcing member preferably connects the opposing ribs of the radially outer annular body and the radially inner annular body.

[0009] Furthermore, in the above embodiment, it is preferable that a plurality of the shear reinforcing members are arranged along the axial direction in a single steel segment.

[0010] Furthermore, in the above embodiment, it is preferable that the shear reinforcing member is arranged along the radial direction of the annular body.

[0011] Furthermore, in the above embodiment, it is preferable that the shear reinforcing member is formed by folding both ends in a hook shape, and that one of the ribs of the radially outer annular body and the radially inner annular body has a hole for hooking one end of the shear reinforcing member, and that the other rib of the radially outer annular body and the radially inner annular body has a slit for receiving the other end of the shear reinforcing member and a restricting member for restricting the shear reinforcing member from detaching from the slit.

[0012] Furthermore, in the above embodiment, it is preferable that the shear reinforcement member is formed in a plate shape and that both ends are connected to the opposing ribs.

[0013] Furthermore, in the above embodiment, it is preferable that the shear reinforcement member has a plurality of holes.

[0014] Furthermore, in the above embodiment, it is preferable that the shear reinforcement member is formed by folding both ends in a hook shape, and that the ribs of the radially outer annular body and the radially inner annular body each have a locking portion that locks the end of the shear reinforcement member.

[0015] Furthermore, in the above embodiment, it is preferable that the shear reinforcing member has protrusions at both ends, and that the ribs of the radially outer annular body and the radially inner annular body each have holes into which the protrusions are inserted.

[0016] Furthermore, in the above embodiment, it is preferable that the shear reinforcing member has a base connected to the ribs of the radially outer annular body and the radially inner annular body, and a connecting member whose ends are fitted into the respective bases.

[0017] Furthermore, in the above embodiment, it is preferable that the shear reinforcing member includes a base connected to one of the ribs of the radially outer annular body and the radially inner annular body, and a connecting member whose one end is fitted into the base and whose other end is locked to the other rib.

[0018] Furthermore, it is preferable that at least a portion of the reinforcing member is a main reinforcement bar.

[0019] Furthermore, it is preferable that at least a portion of the reinforcing member is made of structural steel.

[0020] Furthermore, it is preferable that the shaped steel has irregularities formed on at least a portion of its surface.

[0021] One aspect of the present invention has a plate forming a wall surface, a joint part erected at a longitudinal end of the plate, and a main girder erected at a short-side end of the plate, and is an annular body having a plurality of steel segments arranged annularly and a connecting mechanism connecting adjacent steel segments to each other, wherein the steel segment is provided with a locking part of a shear reinforcing member for connecting to a steel segment of another annular body arranged on the outer side or the inner side in the radial direction of the annular body.

[0022] Further, in the above aspect, it is preferable that the steel segment includes a plurality of ribs erected between longitudinal ends of the plate in the plate, and the locking part of the shear reinforcing member is provided on the rib.

[0023] One aspect of the present invention is a steel segment that has a plate forming a wall surface, a joint part erected at a longitudinal end of the plate, and a main girder erected at a short-side end of the plate, and is annularly connected to form an annular body, and is provided with a locking part of a shear reinforcing member for connecting to a steel segment of another annular body arranged on the outer side or the inner side in the radial direction of the annular body.

[0024] Further, in the above aspect, it is preferable that the plate includes a plurality of ribs erected between longitudinal ends of the plate, and the locking part of the shear reinforcing member is provided on the rib.

[0025] One aspect of the present invention is a construction method of a foundation structure, which includes a step of longitudinally connecting a plurality of steel segments to construct an outer annular body and an inner annular body in the radial direction that replace the stirrups, a step of connecting the outer annular body and the inner annular body in the radial direction with a shear reinforcing member, a step of connecting a plurality of the outer annular body and the inner annular body in the radial direction connected by the shear reinforcing member along the axial direction of the annular body, a step of arranging a reinforcing member along the axial direction of the annular body, and a step of filling a filler between the outer annular body and the inner annular body in the radial direction.

[0026] One aspect of the present invention is a method for constructing a foundation structure, comprising: (a) connecting a plurality of steel segments longitudinally to construct an annular body on the radially outer side that substitutes for stirrups, and connecting a plurality of the annular bodies along the axial direction; (b) in the space formed inside the annular body on the radially outer side, connecting a plurality of steel segments longitudinally to construct an annular body on the radially inner side that substitutes for stirrups; (c) connecting the annular body on the radially outer side and the annular body on the radially inner side with a shear reinforcement member; (d) repeating steps (b) and (c) to connect the annular body on the radially inner side to all of the annular bodies on the radially outer side with the shear reinforcement member; (e) arranging a reinforcement member along the axial direction of the annular body; and (f) filling a filling material between the annular body on the radially outer side and the annular body on the radially inner side.

[0027] Also, in the above aspect, in the construction of the annular body, it is preferable to have a step of attaching a scaffold to the steel segment and a step of replacing the scaffold with a steel segment constituting another annular body when constructing another annular body above the constructed annular body.

Advantages of the Invention

[0028] According to the above aspect, a foundation structure capable of coping with large-diameter and large-depth construction can be constructed.

Brief Description of the Drawings

[0029] [Figure 1] It is a schematic view showing a pier and a floor slab based on a foundation structure. [Figure 2] It is a plan view of the foundation structure. [Figure 3] It is a plan view of the steel segment. [Figure 4] It is a view seen from the I-I direction in FIG. 3. [Figure 5] It is an enlarged view of the connecting portion between the outer ring body and the inner ring body by the shear reinforcement member. [Figure 6]This is a front view of the steel segment as seen from the inside. [Figure 7] This is a perspective view illustrating the configuration of the coupling mechanism. [Figure 8] This is a plan view of the steel segments that make up the ring body in the modified example 1. [Figure 9] This is a view from the II-II direction in Figure 8. [Figure 10] This is a plan view of the steel segments that make up the ring body in modified example 2. [Figure 11] This is a view from the III-III direction in Figure 10. [Figure 12] This is a plan view of the steel segments that make up the ring body in modified example 3. [Figure 13] This is a view from the IV-IV direction in Figure 12. [Figure 14] This figure shows the shear reinforcement member in modified example 4. [Figure 15] This figure shows another example of a shear reinforcement member in Figure 14. [Figure 16] This figure shows the reinforcing member in modified example 5. [Figure 17] This is a front view showing an example of a reinforcing member. [Figure 18] This is a side view showing an example of a reinforcing member. [Figure 19] This is a plan view showing an example of a reinforcing member. [Figure 20] This is a diagram showing the reinforcing member in modified example 6. [Figure 21] This figure shows another example of a shear reinforcement member in Modification Example 1. [Modes for carrying out the invention]

[0030] Preferred embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are illustrative and various forms are possible without departing from the spirit of the present invention. One embodiment of the foundation structure according to the present invention serves as the foundation for a building on the ground, for example, as the foundation (sill) of a bridge pier. The foundation structure is constructed as a reinforced concrete structure and embedded in the ground. The building to which the foundation structure is applied is not limited to bridge piers, but may also be a high-rise building or an apartment building, etc.

[0031] Figure 1 is a schematic diagram showing a bridge pier 100 and deck slab 110 based on a foundation structure 1. The deck slab 110 supported by the bridge pier 100 is the part on which vehicles such as automobiles and trains travel, and where the load of the vehicles is directly applied. For the sake of explanation, in the following, the centerline of the foundation structure 1 will be referred to as axis x. The direction in which the foundation structure 1 is embedded along axis x will be referred to as the embedding direction A, and the direction around axis x will be referred to as the circumferential direction C.

[0032] <Foundation structure> The foundation structure 1 is constructed beneath the bridge pier 100. The foundation structure 1 is formed, for example, in a cylindrical shape. The foundation structure 1 comprises a cylindrical segment structure 10, a filling section (concrete section) 20, and main reinforcement bars (reinforcement members) 30.

[0033] Figure 2 is a plan view of the foundation structure 1. The segment structure 10 extends along an axis x that extends along the burial direction A. The segment structure 10 is formed in an annular shape in the circumferential direction C and is also formed to extend in the burial direction A. That is, the direction of the segment structure 10 along axis x coincides with the burial direction A. The segment structure 10 forms the earth retaining wall when constructing the foundation structure 1, and also forms the concrete formwork when constructing the infill section 20. The segment structure 10 comprises radially outward outer ring bodies (annular bodies) 11 connected in multiple stages in the burial direction A along the axis x, an inner ring body (annular body) 12 provided radially inward of the outer ring body 11 and facing the outer ring body 11, and a shear reinforcement member 60 connecting the outer ring body 11 and the inner ring body 12. In other words, the segment structure 10 has multiple ring bodies 11 and 12 connected along the axis x arranged in a double radial configuration and connected by the shear reinforcement member 60, with main reinforcement bars 30 placed between the outer ring body 11 and the inner ring body 12 and filled with filling material 20 to integrate them.

[0034] Each ring body 11, 12 has multiple steel segments 40 connected to each other in a ring shape in the circumferential direction C, and functions as a stirrup replacement part that replaces the stirrups of the foundation structure 1. That is, multiple ring bodies 11, 12 are connected in the burial direction A to constitute the foundation structure 1, and each ring body 11, 12 replaces the stirrups that would normally be provided in the foundation structure 1. Therefore, the ring bodies 11, 12 that replace the stirrups are arranged in a ring shape along the direction intersecting the main reinforcement 30 (the cross-sectional direction of the foundation structure 1 perpendicular to the burial direction A). In ring bodies 11, 12 adjacent to each other in the vertical direction (burial direction A) along axis x, the ends of the upper ring body 11, 12 and the steel segments 40 of the lower ring body 11, 12 are offset in the circumferential direction C, and are arranged in a staggered pattern. The number of steel segments 40 connected in the circumferential direction C is appropriately changed based on the size (outer diameter) of the foundation structure 1 to be constructed.

[0035] Figure 3 is a plan view of the steel segments 40 that make up the ring bodies 11 and 12. Figure 4 is a view from direction II in Figure 3. Figure 5 is a magnified view of the connection portion between the outer ring body 11 and the inner ring body 12 by the shear reinforcement member 60. Figure 6 is a front view of the steel segment 40 seen from the inside. Figure 7 is a perspective view illustrating the configuration of the connection mechanism 50. Note that in Figure 3, the main girder 42 on the upper side in the x-axis direction is drawn as a perspective view to make the configuration of the rib 44 and the shear reinforcement member 60 easier to see. In Figure 4, the state before the shear reinforcement member 60 is restricted by the restricting member 45 is depicted.

[0036] Each ring body 11, 12 comprises a plurality of steel segments 40 that are continuously connected in the circumferential direction C (longitudinal direction), and a connecting mechanism 50 that connects adjacent steel segments 40 in the circumferential direction C. The steel segment 40 is made of steel. The steel segment 40 has a plate 41, a main girder 42, a joint portion 43, and ribs (stiffeners) 44. In the steel segment 40, the plate 41, the main girder 42, and the joint portion 43 define a filling space S into which concrete forming the infill portion 20 is filled. The main girder 42, the joint portion 43, and the ribs 44 may all be joined to the plate 41 by welding, or a part of them may be integrally formed with the plate 41.

[0037] Plate 41 forms the outer wall surface of the foundation structure 1, specifically the segment structure 10. Plate 41 is formed in a rectangular shape in plan view. Plate 41 is formed with an arc-shaped curve. The curvature of plate 41 is determined based on the size of the foundation structure 1 to be constructed.

[0038] The main girders 42 are erected on the two edges (short-side edges) of the plate 41 that extends along the circumferential direction C. The main girders 42 are formed in a curved shape along the plate 41. The main girders 42 are approximately perpendicular to the plate 41 and are erected on the inner surface of the plate 41. When the ring bodies 11 and 12 are stacked in the vertical direction, adjacent main girders 42 in the vertical direction face each other. One main girder 42 is provided on the edge located on the above-ground side. The other main girder 42 is provided on the edge located on the underground side.

[0039] Multiple holes 42a are formed in each main girder 42. The hole 42a is a connecting hole through which a connecting device (not shown), such as a bolt, is inserted to connect it to other steel segments 40 adjacent to it above and below. The hole 42a is formed, for example, in a circular shape and penetrates through the main girder 42 in the thickness direction (direction along the axis x). The hole 42a is formed to have a diameter slightly larger than the cross-section of the connecting device (approximately the outermost diameter of the connecting device + 3 to 6 mm), but it does not need to be large enough for the concrete to be poured to pass through. Of course, the hole 42a may be formed to be large enough for the aggregate contained in the concrete to pass through the gap between the hole 42a and the connecting device. Note that the hole 42a is not limited to a circular shape, but may also be formed in an elliptical, oblong, or rectangular shape, and its shape and size can be freely changed within the range that satisfies the design strength of the main girder 42. The holes 42a are formed approximately in the center of the main girder 42 in the short direction (width direction). The holes 42a are provided at predetermined intervals in the direction of extension of the main girder 42, from one end to the other in the circumferential direction C. The holes 42a of each main girder 42 facing each other along the axis x are formed to be coaxial with each other. Furthermore, the main girder 42 may have venting holes to release air from the filling space S when filling with concrete. The holes may be sized to allow only air to pass through, or they may be sized to allow aggregates contained in the concrete to pass through. In addition, the number of holes formed in a single main girder 42 and the positions of the holes can be freely changed.

[0040] The joint portions 43 are provided on the edges (longitudinal edges) that extend along the axis x at each end of the plate 41 in the circumferential direction C. The joint portions 43 extend along the axis x between the main girders 42 at the ends of the main girders 42 in the circumferential direction C. The joint portions 43 contact and connect with the joint portions 43 of other adjacent steel segments 40 in the circumferential direction C. The joint portion 43 is erected on the inner surface of the plate 41 so as to extend from the plate 41 toward the axis x. One end of the joint portion 43 extending along the axis x is connected to the plate 41, and the other end extends to just before the inner edge of the main girder 42. The edges of the joint portion 43 extending toward the axis x are each connected to the main girder 42. The joint portion 43 has three holes 43a formed in two rows along the axis x, spaced at predetermined intervals along the axis x, through which connecting parts 51 (see Figure 2), such as bolts, are inserted. In addition to the hole 43a, the joint portion 43 has a plurality of holes 43b formed along its embedding direction A (longitudinal direction). The holes 43b are holes that connect the spaces V of adjacent steel segments 40 when concrete is filled in, and are holes that allow the concrete to flow into each other's spaces V. Therefore, it is preferable that the holes 43b of opposing joint portions 43 in adjacent steel segments 40 are formed concentrically. The holes 43b are formed, for example, in a circular shape and penetrate through the joint portion 43 in the thickness direction. The holes 43b are formed to be large enough for aggregate contained in the concrete to pass through. Note that the holes 43b are not limited to a circular shape, but may be formed in an elliptical, oblong, or rectangular shape, and their shape and size can be freely changed within the range that satisfies the design strength of the joint portion 43. Specifically, from the viewpoint of concrete flowability, the minimum diameter of the hole 43b is preferably larger than the maximum size of the fine aggregate contained in the concrete, which is 10 mm, and the maximum diameter is preferably 1 / 3 or less of the width of the joint (in the direction perpendicular to the axis of the foundation) from the viewpoint of its influence on the strength of the joint 43. For example, six holes 43b are formed so as to sandwich the holes 43a from the longitudinal direction of the joint portion 43. The number of holes 43b is not limited and can be freely changed within the range that satisfies the design strength of the joint portion 43.

[0041] Multiple ribs 44 are provided on the inner surface of the plate 41, extending along the axis x between the two main girders 42. The ribs 44 are provided at predetermined intervals between joint portions 43 provided at each end of the steel segment 40 in the circumferential direction C. The ribs 44 are erected so as to extend from the plate 41 toward the axis x. One end of the rib 44 extending along the axis x is connected to the plate 41, and the other end extends to the inner edge of the main girder 42. The ends of the ribs 44 extending toward the axis x are each connected to the main girder 42. The ribs 44 of the outer ring body 11 have holes 44a formed therein for hooking one end of the shear reinforcement member 60. A slit 44b is formed in the rib 44 of the inner ring body 12 to receive the other end of the shear reinforcement member 60. The slit 44b is formed to communicate with the edge of the outer ring body 11 that is opposite to the rib 44. Here, multiple holes 44a and slits 44b are formed in the rib 44 so that they are at the same height along the axis x. The rib 44 of the inner ring body 12 is provided with a restricting member 45 that restricts the shear reinforcing member 60 from detaching from the slit 44b, with one end of the shear reinforcing member 60 locked in the hole 44a and the other end received in the slit 44b. In other words, the hole 44a and the restricting member 45 function as locking parts for the shear reinforcing member 60. As shown in Figure 5, the restricting member 45 comprises, for example, two plate members 45a and a fastener 45b. The plate members 45a sandwich the rib 44 from both sides while closing the slit 44b, so that the shear reinforcement member 60 does not detach from the slit 44b when the other end of the shear reinforcement member 60 is received in the slit 44b, and the two plate members 45a and the rib 44 are connected by a fastener (for example, a bolt and nut) 45b. Alternatively, a slit 44b may be formed in the rib 44 of the outer ring body 11, and a hole 44a may be formed in the rib 44 of the inner ring body 12.

[0042] As shown in Figures 6 and 7, the connecting mechanism 50 comprises a connecting portion 51, a second joint portion 52, a joint rib 53, and a filling portion 54. The connecting portion 51 is inserted through the joint portion 43 and the second joint portion 52, connecting adjacent steel segments 40 in the circumferential direction C (longitudinal direction). The connecting portion 51 is composed of, for example, a bolt 51a and a nut 51b. The connecting portion 51 is inserted through the hole 43a formed in the joint portion 43 and the hole 52a formed in the second joint portion 52. The second joint portion 52 is provided parallel to each joint portion 43, at a predetermined distance in the circumferential direction C from each joint portion 43, near both ends of the steel segment 40 in the circumferential direction C. The second joint portion 52 is provided on the inner surface of the plate 41 and is erected so as to extend from the inner surface toward the axis x. One end of the second joint portion 52 extending along the axis x is connected to the plate 41, and the other end extends to the inner edge of the main girder 42. Both ends of the second joint portion 52 extending toward the axis x are connected to the main girder 42.

[0043] The second joint portion 52 has a plurality of holes 52a formed at predetermined intervals along the axis x for inserting the bolts 51a of the connecting portion 51. For example, six holes 52a are formed, with three holes 52a arranged along the short direction (embedding direction A) of the steel segment 40 and two rows formed along the thickness direction of the steel segment 40. The holes 43a of the joint portion 43 and the holes 52a of the second joint portion 52 are located opposite each other in the circumferential direction C. Therefore, six bolts 51a are also provided to be inserted through both holes 43a and 52a, and adjacent steel segments 40 are connected by these six bolts 51a and nuts 51b. When connecting adjacent steel segments 40 in the circumferential direction C, bolts 51a of the connecting portion 51 are inserted through the holes 43a and 52a of the four joint portions 43 and 52, respectively, and nuts 51b are screwed onto each end of the bolts 51a from the outside of the second joint portion 52. At this time, the nuts 51b are in contact with each second joint portion 52. As a result, the steel segments 40 are connected to each other in the circumferential direction C. When a bolt 51a with a head is used, the head of the bolt 51a abuts against one of the second joint portions 52, and the nut 51b abuts against the other second joint portion 52 and is screwed onto the bolt 51a. As a result, the steel segments 40 are connected to each other in the circumferential direction C.

[0044] In addition to the hole 52a, the second joint portion 52 has a plurality of holes 52b formed along its embedding direction A (longitudinal direction). The holes 52b are holes that connect the inside and outside of the space V when concrete is filled, and are holes that allow concrete to flow between the inside and outside of the space V. The holes 52b are formed, for example, in a circular shape and penetrate through the second joint portion 52 in the thickness direction. The holes 52b are formed to be large enough for aggregate contained in the concrete to pass through. Note that the holes 52b are not limited to a circular shape, but may be formed in an elliptical, oblong, or rectangular shape, and their shape and size can be freely changed within the range that satisfies the design strength of the second joint portion 52. Specifically, from the viewpoint of concrete flowability, the minimum diameter of the hole 52b is preferably larger than 10 mm, which is the maximum size of the fine aggregate contained in the concrete, and the maximum diameter is preferably 1 / 3 or less of the width of the second joint 52 (in the direction perpendicular to the axis of the foundation) from the viewpoint of its influence on the strength of the second joint 52. For example, six holes 52b are formed so as to sandwich the holes 52a from the longitudinal direction of the second joint portion 52. The number of holes 52b is not limited and can be freely changed within a range that satisfies the design strength of the second joint portion 52. Furthermore, it is preferable that the holes 52b are formed in positions opposite to the holes 43b along the circumferential direction C, but the holes 52b are not limited to this position.

[0045] The joint ribs 53 are provided between adjacent joint portions 43 and the second joint portion 52 in the circumferential direction C. The joint ribs 53 are provided parallel to the main girder 42 so as to intersect with the axis x. Each joint rib 53 is provided parallel to each other at a predetermined interval along the axis x. More specifically, each joint rib 53 is provided between each bolt 51a of the connecting portion 51, along the axial direction of the bolt 51a. Each joint rib 53 is provided on the inner surface of the plate 41 and is erected so as to extend from the inner surface toward the axis x. One end of each joint rib 53 in the direction intersecting the axis x is connected to the joint portion 43, and the other end is connected to the second joint portion 52. As a result, each joint rib 53 partitions the space V enclosed by the joint portion 43 and the second joint portion 52. A hole 53b is formed in the joint rib 53 at approximately its center. The hole 53b is a hole that connects the spaces partitioned by the joint rib 53 within the space V when concrete is filled, and is a hole that allows concrete to flow between the spaces. The hole 53b is formed, for example, in a circular shape and penetrates through the joint rib 53 in the thickness direction. The hole 53b is formed to be large enough for the aggregate contained in the concrete to pass through. Note that the hole 53b is not limited to a circular shape, but may be formed in an elliptical, oblong, or rectangular shape, and its shape and size can be freely changed within the range that satisfies the design strength of the joint rib 53. Specifically, from the viewpoint of concrete flowability, it is preferable that the minimum diameter of the hole 53b be larger than the maximum size of the fine aggregate contained in the concrete, which is 10 mm, and the maximum diameter be 1 / 3 or less of the width of the joint rib 53 (in the direction perpendicular to the axis of the foundation) from the viewpoint of the influence on the strength of the joint rib 53. For example, one hole 53b is formed near the center of the joint rib 53. The number of holes 53b is not limited and can be freely changed within the range that satisfies the design strength of the joint rib 53. Furthermore, it is preferable that the holes 53b formed in each joint rib 53 are formed at positions opposite each other along the burial direction A, but the holes 53b are not limited to this position.

[0046] The filling section 54 is provided within the space V enclosed by the plate 41, the main girder 42, the joint section 43, and the second joint section 52, and is integrated with the bolts 51a of the connecting section 51. Specifically, the filling section 54 is made of concrete and is integrated with the steel segment 40 and the connecting mechanism 50 by being poured into the space V and hardening. Here, the space V is partitioned by the joint rib 53, and the space V is divided into multiple spaces. The filling section 54 is formed when the concrete poured when constructing the infill section 20 is filled into the space V.

[0047] Here, the spacing between adjacent holes 43a and 52a is determined so that the pitch spacing of the bolts 51a inserted through these holes 43a and 52a is less than or equal to the pitch spacing required for the stirrups in the design. In addition, the material of the bolts 51a is selected so that the strength (yield stress) of the bolts 51a is greater than or equal to the strength (yield stress) of the stirrups.

[0048] The shear reinforcement member 60 is formed, for example, from reinforcing steel. The shear reinforcement member 60 connects the ribs 44 of the outer ring body 11 and the opposing ribs 44 of the inner ring body 12. The shear reinforcement member 60 is formed by folding both of its longitudinal ends in a hook shape. One end of the shear reinforcement member 60 is hooked into the hole 44a of the rib 44 of the outer ring body 11, and the other end is received into the slit 44b of the rib 44 of the inner ring body 12, and is restricted by the regulating member 45 to prevent it from coming out of the slit 44b. As a result, the shear reinforcement members 60 are arranged in multiple locations along the axial x-direction and along the radial direction of each ring body 11, 12. The ribs, shear reinforcement members, and connections made by welding or bolts and nuts are set to meet the required strength and rigidity for shear reinforcement members. The same conditions apply to subsequent modifications.

[0049] The main reinforcement bars 30 are, for example, reinforcing bars made of steel. The main reinforcement bars 30 are provided on a predetermined virtual circle centered on axis x. The main reinforcement bars 30 extend along the burial direction A and are provided at predetermined intervals in the circumferential direction C. Note that the main reinforcement bars 30 provided at the same location in the segment structure 10 may be a single reinforcing bar extending along axis x, or they may be formed by multiple reinforcing bars having predetermined lengths. The main reinforcement bars 30 extend at least from the upper end on the above-ground side to the other end on the underground side of the segment structure 10. The main reinforcement bars 30 are arranged at predetermined intervals along the edge of the main girder 42 on the side of the main girder 42 opposite to the plate 41 of each steel segment 40. That is, the main reinforcement bars 30 are provided between the outer ring body 11 and the inner ring body 12. The main reinforcement bars 30 are formed integrally with the steel segment 40 by the solidification of the infill portion 20 cast inside the segment structure 10.

[0050] The filling portion 20 is made of concrete, for example, and is filled between the outer ring body 11 and the inner ring body 12 in a double cylindrical segment structure 10 formed by connecting the outer ring body 11 and the inner ring body 12 in the height direction.

[0051] <Method of constructing foundation structures> Next, we will explain the construction method for the foundation structure 1. As a preliminary step, a sinking anchor is installed, and a sinking device (not shown) is set up at the construction site where the foundation structure 1 will be constructed. Below the sinking device, a cutting edge ring (not shown) is installed at the lowest end of the foundation structure 1. The ground inside the installed cutting edge ring is excavated with a clamshell attached to the end of a crawler crane. Once the excavation to the depth required for sinking the cutting edge ring into the ground is complete, the excavation is stopped, and the top surface of the cutting edge ring is pressed into the ground by the sinking device, sinking the cutting edge ring into the ground. After the cutting edge ring is sunk, a guide ring is placed on top of the axially upper side of the cutting edge ring and connected. After the guide ring is connected, the ground inside the guide ring is excavated with a clamshell. Once the excavation to the depth required for sinking the guide ring into the ground is complete, the excavation is stopped, and the top surface of the guide ring is pressed into the ground by the sinking device, sinking the guide ring into the ground. After repeating the connection and sinking of the guide ring a predetermined number of times, a workbench ring is placed on top of the axially upper side of the guide ring and connected. After connecting the work platform rings, the ground inside the guide ring is excavated with a clamshell. Once the excavation reaches the depth required to sink the work platform ring into the ground, the excavation is stopped, and the top surface of the work platform ring is pressed into the ground using a sinking device, thereby sinking the work platform ring into the ground.

[0052] Next, the steel segments 40 are connected to assemble the annular outer ring body 11. Specifically, the steel segments 40 are connected at the upper end surfaces that protrude inward from the workbench ring to form the annular outer ring body 11. After the outer ring body 11 is formed, the ground inside the outer ring body 11 is excavated with a clamshell. Once the excavation to the depth required for sinking the outer ring body 11 into the ground is complete, the excavation is stopped, and the upper surface of the outer ring body 11 is pressed into the ground with a sinking device to sink the outer ring body 11 into the ground. Above the axial direction of the sunk outer ring body 11, the scaffolding is moved to the upper outer ring body 11, and another outer ring body 11 is formed by connecting the steel segments 40. This process is repeated until a predetermined depth is reached. In this way, all the outer ring bodies 11 necessary for constructing the foundation structure 1 are connected and sunk along the axial direction. After all the outer ring bodies 11 have been submerged, underwater concrete is poured into the bottom of the inside of the outer ring bodies 11 to construct the base. Then, an underwater pump (not shown) is installed in the groundwater inside the outer ring bodies 11 to discharge the groundwater to the outside of the outer ring bodies 11. The outer ring body 11 is constructed through the above process.

[0053] Next, the inner ring body 12 is assembled inside the outer ring body 11 in the same manner as the outer ring body 11. When assembling the inner ring body 12, scaffolding provided inside the inner ring body 12 is used. The scaffolding is attached to the steel segment 40. Specifically, the scaffolding is secured to a plate provided on the plate 41. After constructing the inner ring body 12, the outer ring body 11 and the inner ring body 12 are connected by shear reinforcement members 60. Along with the connection work between the outer ring body 11 and the inner ring body 12, main reinforcement bars 30 are placed near the outer ring body 11 and near the inner ring body 12. These main reinforcement bars 30 are placed in the space sandwiched between the outer ring body 11 and the inner ring body 12. When constructing another inner ring body 12 on top of the constructed inner ring body 12, the scaffolding is replaced with steel segments 40 that make up the other inner ring body 12. Then, the other inner ring body 12 is stacked and connected on top of the inner ring body 12 that is connected to the outer ring body 11. In addition, the opposing outer ring body 11 and inner ring body 12 are connected by shear reinforcement members 60. Along with the connection work between the outer ring body 11 and the inner ring body 12, main reinforcement bars 30 are placed near the outer ring body 11 and near the inner ring body 12. The above process is repeated until a predetermined depth is reached. This allows all the inner ring bodies 12 necessary for constructing the foundation structure 1 to be constructed and connected to the outer ring body 11. Next, concrete is poured into the space sandwiched between the outer ring body 11 and the inner ring body 12. Through the above process, the foundation structure 1 is constructed. Furthermore, the concrete may be poured after the construction of each ring body 11 and 12 is completed, or it may be poured in stages during the construction of each ring body 11 and 12.

[0054] Furthermore, it is also possible to construct the foundation structure 1 using the following method. A sinking device (not shown), for example, consisting of a hydraulic jack, is installed at the location where the foundation structure 1 is to be constructed. Multiple sinking devices are provided at various locations along the circumferential direction C of the annular foundation structure 1. Next, the steel segments 40 are connected in the circumferential direction C (longitudinal direction) inside the sinking device to construct an outer ring body 11 and an inner ring body 12 that replace the stirrups. When forming each ring body 11 and 12, bolts 51a are inserted through the joint portion 43 and the second joint portion 52 and fastened with nuts 51b. Then, the outer ring body 11 and the inner ring body 12 are connected by a shear reinforcement member 60. Furthermore, another ring body 11, 12 is formed on top of the existing ring bodies 11, 12 and connected to them. Yet another ring body 11, 12 is formed on top of this other ring body 11, 12 and connected to them. The ground inside the ring bodies 11, 12 is excavated using a clamshell (not shown). Once the excavation to the depth necessary to sink the ring bodies 11, 12 into the ground is completed, the excavation is stopped and the upper surfaces of the ring bodies 11, 12 are pressed into the ground by a sinking device, thereby pressing the ring bodies 11, 12 into the ground. Each ring body 11, 12 is connected by a shear reinforcement member 60.

[0055] Next, several more ring bodies 11,12 are assembled above the previously sunk ring bodies 11,12. The ground inside the ring bodies 11,12 is excavated to the required depth using a clamshell, and the ring bodies 11,12 are pressed into the ground by a sinking device, sinking them into the ground. This process is repeated until a predetermined depth is reached. This constructs a cylindrical segment structure 10 in which multiple ring bodies 11,12 are connected underground along an axis x. In the ring bodies 11 adjacent to each other vertically, the positions of the joints 43 of the steel segments 40 are offset from each other in the circumferential direction C, so that the steel segments 40 are arranged in a staggered pattern.

[0056] Next, main reinforcement bars 30 are inserted along the axis x of the main girder 42 of each steel segment 40 in the outer ring body 11, and main reinforcement bars 30 are also inserted along the axis x of the main girder 42 of each steel segment 40 in the inner ring body 12. The main reinforcement bars 30 may be made by inserting multiple reinforcing bars of a predetermined length through the same hole 42c in the uppermost ring body 11 of the segment structure 10, and connecting them along the way as appropriate.

[0057] After installing the main reinforcement bars 30 around the entire circumference, concrete is poured between the outer ring body 11 and the inner ring body 12. The poured concrete spreads toward the plate 41. As the concrete is gradually poured, its volume increases toward the ground. The concrete fills the filling space S while pushing out the air in the filling space S from the holes 42b. Therefore, it is possible to reliably prevent the formation of air pockets in the foundation structure 1. Furthermore, the concrete also flows into the space V enclosed by the plate 41, main girder 42, joint section 43, and second joint section 52, which are open to the inside of the segment structure 10. After the concrete hardens, it becomes a filling section 54 and integrates with the bolts 51a of the connecting section 51. This integrates adjacent steel segments 40 together and strengthens the connection.

[0058] Concrete is poured up to the upper end of the segment structure 10 to form the infill section 20. As a result, the main reinforcement bars 30 and the steel segments 40 are integrated with each other via the infill section 20, and the foundation structure 1 is constructed. At this time, the main reinforcement bars 30 function as the main reinforcement bars of the foundation structure 1 (reinforced concrete structure), and the ring bodies 11 and 12, to which the steel segments 40 are connected by the connecting mechanism 50, function as stirrups of the foundation structure 1 (reinforced concrete structure). In addition, the shear reinforcement member 60 connecting the outer ring body 11 and the inner ring body 12 increases the strength against shear. The method of constructing the foundation structure 1 by pressing in steel segments 40 is extremely suitable, for example, when repairing bridge piers 100 on elevated roads. Under elevated roads, the space in the height direction is limited. In the construction method of building ring bodies 11 and 12 and pressing them into the ground, the space limitations in the height direction are minimal. The main reinforcement bars 30 may be inserted each time multiple layers of ring bodies 11 and 12 are sunk into the ground.

[0059] As described above, with the foundation structure 1, an outer ring body 11 and an inner ring body 12 are constructed, the two ring bodies 11 and 12 are connected by shear reinforcement members 60, main reinforcement bars 30 are installed near the outer ring body 11 and near the inner ring body 12, and the infill portion (concrete) 20 is filled between the outer ring body 11 and the inner ring body 12, thereby creating a foundation structure 1 in which the segment structure 10, the infill portion (concrete) 20 and the main reinforcement bars 30 are integrated. As a result, there is no need to pour concrete inside the inner ring body 12, so the weight does not increase significantly, and a foundation structure 1 that can accommodate large diameter and deep construction can be made. Furthermore, since the ring bodies 11 and 12 are connected by a connecting mechanism 50, the ring bodies 11 and 12 with the connected steel segments 40 can be used as a substitute for the stirrups in a reinforced concrete structure, significantly increasing the strength of the joint portion of the segment structure 10. As a result, the segment structure 10, which conventionally could not be used as part of a foundation due to insufficient joint strength, can now be used as part of the foundation structure 1. Furthermore, since the connection of the steel segments 40 serves as the installation of the stirrups, the time-consuming process of installing stirrups in the main reinforcement and the process of installing and removing the internal formwork can be eliminated, thereby shortening the time required to construct the foundation structure 1.

[0060] Furthermore, the smaller the deformation of the connecting mechanism 50 when subjected to tensile force, the greater the restraining force and the more it functions as a stirrup. Here, concrete is filled into the space V surrounded by the plate 41, main girder 42, joint section 43, and second joint section 52. The concrete filled into this space V is deformed by the restraint of each member, resulting in high strength. On the other hand, the rigidity of the concrete filled into space V minimizes the deformation of the connecting mechanism 50. In other words, the filling section 54 formed by concrete becomes integrated with the connecting mechanism 50, thereby minimizing the deformation of the connecting mechanism 50 when tensile force is applied. Furthermore, by forming a space V in the connecting mechanism 50 and filling it with concrete, and then restraining the concrete, the connecting strength of the steel segment 40 can be increased.

[0061] Furthermore, the strength of the foundation structure 1 is increased compared to the conventional structure in which reinforcing bars are crossed and stirrups are provided. In addition, by using steel segments 40, it is no longer necessary to assemble stirrups along the axis at predetermined intervals relative to the main reinforcement bars 30 as in the conventional method, and the work time required to construct the foundation structure 1 can be significantly reduced. Furthermore, in the foundation structure 1, the main girders 42 and joints 43 of the steel segments 40 can also be considered as stirrups, so the entire foundation structure 1 can be used as an extremely strong foundation. Furthermore, since the steel segments 40 and connecting mechanism 50 can replace the stirrups that would normally be provided, the amount of steel used can be significantly reduced without lowering the strength of the foundation structure 1. Furthermore, in the connecting mechanism 50, the connection of the steel segments 40 can be strengthened by guiding the concrete poured to form the filling portion 20 into the space V, so it is not necessary to fill the space V with filler material in advance.

[0062] Next, we will describe modified versions of the foundation structure. The difference between the following modified versions 1 to 4 and the above embodiment lies in the structure of the shear reinforcement members. The difference between the following modified versions 5 to 6 and the above embodiment lies in the structure of the reinforcement members. Therefore, the following will describe the differences from the above embodiment, and components identical to those in the above embodiment will be denoted by the same reference numerals and their descriptions will be omitted.

[0063] <Example 1> Figure 8 is a plan view of the steel segments 40 that make up the ring bodies 11 and 12. Figure 9 is a view from the direction II-II in Figure 8. Note that in Figure 8, the main girder 42 on the upper side in the x-axis direction is drawn as a transparent view in order to make the structure of the ribs 44 and shear reinforcement members 70 easier to see. The shear reinforcement member 70 is formed from, for example, a steel plate. The shear reinforcement member 70 connects the ribs 44 of the outer ring body 11 and the opposing ribs 44 of the inner ring body 12. Both ends of the shear reinforcement member 70 are connected to the opposing ribs 44 by fasteners (bolts and nuts) 71. In other words, the fasteners 71 function as locking parts for the shear reinforcement member 70. Note that the shear reinforcement member 70 is not limited to being connected to the ribs 44 by fasteners 71; bolts or dowels may be welded to the ribs 44, and the shear reinforcement member 70 may be locked to the bolts or dowels. The shear reinforcement member 70 has multiple holes 70a that penetrate in the thickness direction of the plate. These holes 70a enhance the fluidity of the filling portion (concrete) 20. The plate thickness portion excluding the holes 70a is set to satisfy the required strength and rigidity as a shear reinforcement member 70, calculated from the cross-sectional area and material strength. From the viewpoint of concrete flowability, the minimum diameter of the holes 70a is larger than the maximum size of the fine aggregate contained in the concrete, which is 10 mm, and from the viewpoint of the impact on the strength of the plate, it is preferable that the distance between the centers of the holes 70a is at least three times the diameter of the holes 70a. The shape and number of holes 70a are arbitrary, and the holes 70a may be arranged in a staggered pattern. As a result, although the shear reinforcement member 70 is a single plate, the portion other than the hole 70a connects the ribs 44 at multiple points along the radial direction of each ring body 11, 12, and can perform the same function as if multiple shear reinforcement members 70 were provided. This configuration minimizes the number of connections between the rib 44 and the shear reinforcement member 70, thereby reducing the number of work steps.

[0064] <Modification 2> Figure 10 is a plan view of the steel segments 40 that make up the ring bodies 11 and 12. Figure 11 is a view from the direction III-III in Figure 10. Note that in Figure 10, the main girder 42 on the upper side in the x-axis direction is drawn as a perspective view to make the structure of the ribs 44 and shear reinforcement members 80 easier to see. The shear reinforcement member 80 is formed, for example, from reinforcing steel. The shear reinforcement member 80 connects the ribs 44 of the outer ring body 11 and the opposing ribs 44 of the inner ring body 12. The shear reinforcement member 80 is formed by folding both of its longitudinal ends in a hook shape. One end of the shear reinforcement member 80 is locked to a locking portion 81 provided on the rib 44 of the outer ring body 11, and the other end is locked to a locking portion 82 provided on the rib 44 of the inner ring body 12. In other words, the locking portions 81 and 82 function as locking portions for the shear reinforcement member 80. Multiple locking portions 81 and 82 are provided on the rib 44 so that they are at the same height in the axial x direction. The locking portions 81 and 82 are provided on each rib 44 so as to face each other in the radial direction of each ring body 11, 12. The locking portions 81 and 82 are formed by welding dowels or bolts so that they are erected against the surface of the rib 44. Of course, the shape is not limited as long as it can be configured to lock the end of the shear reinforcement member 80. The shear reinforcement member 80 may also be connected to the rib 44 by fasteners such as bolts and nuts, rather than being locked to the locking portions 81 and 82. As a result, when the shear reinforcing members 80 are locked to the locking portions 81 and 82, multiple members are provided along the axial x direction and are arranged parallel to each other along the radial direction of each ring body 11 and 12. With this configuration, the shear reinforcement member 80 only needs to be hooked onto the locking parts 81 and 82, eliminating the need for fastening and simplifying the installation process. The procedure for positioning the shear reinforcement member 80 is not limited to the method described above; it may also involve hooking the shear reinforcement member 80 onto one of the locking parts 81(82), adjusting the shear reinforcement member 80 to the appropriate position, and then installing the other locking part 82(81).

[0065] <Variation 3> Figure 12 is a plan view of the steel segments 40 that make up the ring bodies 11 and 12. Figure 13 is a view from the IV-IV direction in Figure 12. Note that in Figure 12, the main girder 42 on the upper side in the x-axis direction is drawn with perspective in order to make the structure of the ribs 44 and shear reinforcement members 90 easier to see. The shear reinforcement member 90 is formed from, for example, a rod such as a reinforcing bar. The shear reinforcement member 90 connects the ribs 44 of the outer ring body 11 and the opposing ribs 44 of the inner ring body 12. The shear reinforcement member 90 has a main body portion 91 that is formed in a rod shape and extends in a straight line, and protruding portions 92 provided at both ends in the longitudinal direction of the main body portion 91 and projecting in a direction perpendicular to the longitudinal direction of the main body portion 91. The protruding portion 92 is formed from, for example, the same material as the main body portion 91 and is joined to the main body portion 91 by welding. One protrusion 92 is inserted into a hole 44c provided in the rib 44 of the outer ring body 11, and the other protrusion 92 is inserted into a hole 44c provided in the rib 44 of the inner ring body 12. In other words, the protrusions 92 and the holes 44c function as locking parts for the shear reinforcement member 90. The protrusions 92 may also be formed by bending both ends of the main body 91 at a right angle. That is, the shape is not limited as long as the end of the shear reinforcement member 90 can be inserted into the opposing holes 44c. Furthermore, the protrusions 92 are not limited to the same material as the main body 91, and may be manufactured from different materials using casting or a 3D printer. In addition, the shape and manufacturing method of the main body 91 and the protrusions 92 can be freely changed, provided that they have the strength required for the shear reinforcement member 90. Each hole 44c into which a shear reinforcement member 90 is attached is formed in the rib 44 so as to be at the same height in the axial x direction. Each hole 44c is formed in each rib 44 so as to be opposite to each other in the radial direction of each ring body 11, 12. As a result, when inserted into opposing holes 44c, multiple shear reinforcement members 90 are provided along the axial x direction and are arranged parallel to each other along the radial direction of each ring body 11, 12. With this configuration, the shear reinforcement member 90 only needs to have its protruding portion 92 inserted into the hole 44c of the rib 44, eliminating the need for fasteners to connect the members and simplifying the installation process.

[0066] <Modification 4> Figure 14 shows the shear reinforcement member 95. Figure 15 shows the shear reinforcement member 95A. The shear reinforcement member 95 comprises a base 96 connected to each rib 44 of each ring body 11, 12, and a connecting member 97 connecting the bases 96 to each other. The base 96 is formed, for example, from angle steel, and one side is connected to each rib 44 by fasteners (bolts and nuts) 98. That is, the fasteners 98 function as locking parts for the shear reinforcement members 95. Here, the base 96 is connected to each rib 44 so that the other sides face each other. A groove 96a is formed on the other side of the base 96 into which the end of the connecting member 97 is fitted. Each groove 96a to which a shear reinforcement member 95 is attached is formed in the base 96 so that it is at the same height in the axial x direction. The groove 96a has an inclined portion 96b that communicates with the side edge of the base 96 and slopes downward toward the base 96, and a support portion 96c that is continuous with the inclined portion 96b and supports the connecting member 97. The connecting member 97 has a rod-shaped main body portion 97a and stoppers 97b provided at both ends of the main body portion 97a. The main body portion 97a is formed from, for example, a bar material such as reinforcing steel. The main body portion 97a is formed to be narrower than the inclined portion 96b and the support portion 96c in the groove 96a. The stopper 97b is formed to have a larger cross-section than any position in the main body portion 97a and the groove 96a. Therefore, the connecting member 97 can pass through the main body portion 97a from the inclined portion 96b of the groove 96a toward the support portion 96c and is supported by the support portion 96c. In addition, because the groove 96a has an inclined portion 96b and the connecting member 97 has a stopper 97b that is larger than the groove 96a, the connecting member 97 is prevented from coming out of the groove 96a. As a result, when the connecting members 97 are inserted into the opposing grooves 96a of the base 96, multiple shear reinforcement members 95 are provided along the axial x direction and are arranged parallel to each other along the radial direction of each ring body 11, 12. With this configuration, the shear reinforcement member 95 only needs to have the main body 97a of the connecting member 97 inserted into the groove 96a of the base 96, eliminating the need for fasteners and simplifying the installation process. As shown in Figure 15, the shear reinforcement member 95A may have a stopper 97b at one end of the main body portion 97a of the connecting member 97A, and an insertion portion 97c perpendicular to the longitudinal direction of the main body portion 97a at the other end. The insertion portion 97c may then be inserted into a hole formed in one of the opposing ribs 44 and locked in place, thereby connecting the ring bodies 11 and 12 with the shear reinforcement member 95A. In other words, the fastener 98 and the hole formed in one of the ribs 44 function as a locking portion for the shear reinforcement member 95A.

[0067] <Modification 5> Figure 16 shows a reinforcing member in modified example 5. Figure 17 is a front view showing an example of a reinforcing member. Figure 18 is a side view showing an example of a reinforcing member. Figure 19 is a top view showing an example of a reinforcing member. As shown in Figure 16, the reinforcing member 30A is provided in place of at least some of the main reinforcement bars 30 in the modified example 1 described above, and is formed from structural steel. Specifically, between adjacent shear reinforcing members 70, one reinforcing member 30A is provided in place of the three main reinforcement bars 30 lined up along the circumferential direction C of each ring body 11, 12. For example, an H-shaped steel beam can be used as the structural steel beam 30A. Note that the structural steel beam 30A is not limited to an H-shaped steel beam; other structural steel beams such as angle steel or I-shaped steel beams may also be used.

[0068] As shown in Figures 17 to 19, the H-shaped steel beam 30A extends in the Z direction and, when viewed with a line of sight in the Z direction, has a pair of flanges 31, 31 extending in the X direction which intersects (is perpendicular to) the Z direction, and a web 32 extending in the Y direction which intersects (is perpendicular in this modified example) the X and Z directions. The flanges 31 are connected to both ends of the web 32 in the Y direction. Furthermore, the web 32 is connected to the central part of the flanges 31 in the X direction. Thus, the H-shaped steel beam 30A has an H-shape when viewed with a line of sight in the Z direction. The flange 31 has a main surface 31B on the web 32 side in the Y direction and a main surface 31A on the opposite side of the web 32 in the Y direction. While the main surface 31B is a flat surface, the main surface 31A is formed in a corrugated shape with irregularities. Specifically, the main surface 31A has a shape in which valleys 31Ab (recesses) and peaks 31Aa (protrusions) that project from the valleys 31Ab toward the opposite side of the web 32 in the Y direction are alternately formed in the Z direction when viewed from the X direction. The peaks 31Aa and valleys 31Ab extend in the X direction. The cross-sectional shape of the peaks 31Aa may be curved or trapezoidal, etc. The spacing between the peaks 31Aa may be about 10 times the height (length in the Y direction) of the peaks 31Aa relative to the valleys 31Ab. In this way, the H-shaped steel 30A has a main surface 31A formed in a corrugated shape with peaks 31Aa and valleys 31Ab. In addition, instead of or in addition to the main surface 31A, at least a part of the main surfaces 32A and 32B of the web 32 in the X direction may be formed in a corrugated shape with irregularities.

[0069] As shown in Figure 16, the H-shaped steel beam 30A on the ring body 11 side is provided with a small gap at approximately the center in the circumferential direction C between adjacent shear reinforcement members 70, such that the main surface 31A of one flange 31 faces the inner circumference side of the ring body 11 (the inner circumference side of the main girder 42). The H-shaped steel beam 30A on the ring body 11 side is provided so that its extending direction (X direction) is parallel to the embedding direction A of the ring body 11. The H-shaped steel beam 30A on the ring body 12 side is provided with a small gap so that the main surface 31A of one flange 31 faces the outer circumference side of the ring body 12 (the outer circumference side of the main girder 42) at approximately the center in the circumferential direction C between adjacent shear reinforcement members 70. The H-shaped steel beam 30A on the ring body 12 side is provided so that its extending direction (X direction) is parallel to the embedding direction A of the ring body 12.

[0070] This configuration allows multiple main reinforcement bars 30 to be replaced by a single H-shaped steel beam 30A, thereby reducing the number of components in the segment structure and improving construction efficiency. This, in turn, shortens the construction period. The orientation of the H-shaped steel beams 30A may be rotated 90° around the longitudinal axis relative to the arrangement shown in Figure 16 (so that one of the main surfaces 32A and 32B of the web 32 faces the main girder 42), or it may be rotated by other angles (such as 45° or 60°). Alternatively, all of the main reinforcement bars 30 may be replaced with H-shaped steel bars 30A, or only a portion of the main reinforcement bars 30 may be replaced with H-shaped steel bars 30A. Furthermore, the size of the H-shaped steel beams 30A, which are installed in place of the main reinforcement bars 30, depends on the number of main reinforcement bars 30 that are omitted and the position where the H-shaped steel beams 30A are installed. For example, the size and position of the H-shaped steel beams 30A are designed so that the second moment of area determined by the cross-sectional area and placement of the H-shaped steel beams 30A is greater than the second moment of area determined by the cross-sectional area and placement of the main reinforcement bars 30. Furthermore, not only in the first modified example, but also in the embodiments and modified examples 2 to 4 described above, an H-shaped steel beam 30A can be used instead of the main reinforcement bar 30 as a reinforcing member.

[0071] <Variation 6> Figure 20 shows the reinforcing member in modified example 6. As shown in Figure 20, the reinforcing member 30B is an H-shaped steel beam 30B that is larger in size than the H-shaped steel beam 30A in the modified example 5 described above, and one H-shaped steel beam 30B is provided in place of the six main reinforcements 30 between adjacent shear reinforcing members 70. Note that the steel beam that constitutes the reinforcing member 30B is not limited to an H-shaped steel beam; other steel beams such as angle steel or I-beams may also be used. The H-shaped steel beam 30B, like the modified example 5 described above, has a pair of flanges 31, 31 and a web 32, and is formed so that the width and thickness of the flanges 31, 31 and the web 32 are greater than those of the H-shaped steel beam 30A. The main surface 31A of the flange 31 is formed in a corrugated shape with irregularities. When viewed from the X direction, the main surface 31A has a shape in which valleys 31Ab (recesses) and peaks 31Aa (convex portions) that protrude from the valleys 31Ab on the opposite side of the web 32 in the Y direction are alternately formed in the Z direction. In other words, the H-shaped steel beam 30B is the same as the H-shaped steel beam 30A in terms of configuration other than size.

[0072] As shown in Figure 20, the H-shaped steel beams 30B are spaced apart so that the main surface 31A of one flange 31 faces the inner circumference side of the ring body 11 (the inner circumference side of the main girder 42), and the main surface 31A of the other flange 31 faces the outer circumference side of the ring body 12 (the outer circumference side of the main girder 42), approximately in the center of the circumferential direction C between adjacent shear reinforcement members 70 and approximately in the radial direction between the two ring bodies 11 and 12. The H-shaped steel beams 30B are installed so that their extending direction (X direction) is parallel to the embedding direction A of the ring bodies 11 and 12.

[0073] This configuration allows multiple main reinforcement bars 30 to be replaced by a single H-shaped steel beam 30B, thereby reducing the number of components in the segment structure and improving construction efficiency. This, in turn, shortens the construction period. The orientation of the H-shaped steel beams 30B may be rotated 90° around the longitudinal axis relative to the arrangement shown in Figure 20 (so that one of the main surfaces 32A and 32B of the web 32 faces the main girder 42), or it may be rotated by other angles (such as 45° or 60°). Alternatively, all of the main reinforcement bars 30 may be replaced with H-shaped steel bars 30B, or only a portion of the main reinforcement bars 30 may be replaced with H-shaped steel bars 30B. Furthermore, the size of the H-shaped steel beams 30B, which are installed in place of the main reinforcement bars 30, depends on the number of main reinforcement bars 30 that are omitted and the position where the H-shaped steel beams 30B are installed. For example, the size and position of the H-shaped steel beams 30B are designed so that the second moment of area determined by the cross-sectional area and placement of the H-shaped steel beams 30B is greater than the second moment of area determined by the cross-sectional area and placement of the main reinforcement bars 30. Furthermore, not only in the first modified example, but also in the embodiments and modified examples 2 to 4 described above, an H-shaped steel beam 30B can be used instead of the main reinforcement bar 30 as a reinforcing member.

[0074] <Other> Although preferred embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, but includes all aspects included in the concept and claims of the present invention. Furthermore, the configurations of the above embodiments may be selectively combined as appropriate to achieve at least some of the above-described problems and effects. In addition, for example, the shape, material, arrangement, size, etc., of each component in the above embodiments may be appropriately changed depending on the specific use of the present invention. Furthermore, the main reinforcement bars 30 may be inserted through the main girder 42 of the steel segment 40 itself, or they may be pre-installed. In the height direction, the main reinforcement bars 30 of adjacent steel segments 40 can be joined to each other when connecting them in the height direction. Furthermore, as shown in Figure 21, in the above modified example 1, if the shear reinforcement member 70 has sufficient strength, the hole 70a formed in the shear reinforcement member 70 can be enlarged to further improve the fluidity of the concrete, and the number of fasteners 71 connecting the shear reinforcement member 70 to the rib 44 can be reduced to improve construction efficiency. This makes it possible to shorten the construction period. [Explanation of Symbols]

[0075] 1 Foundation structure 10 Segment Structure 11,12 Ring-shaped body (annular body, substitute for tidal muscle) 20. Filling section (concrete) 30 Main reinforcement bars (reinforcement members) 30A, 30B H-shaped steel (reinforcement member, structural steel) 40 Steel Segments 41 Plates 42 Main digit 43 Joint section 44 Ribs 44a hole 44b Slit 44c hole 45 Regulating members 45a plate material 45b Fasteners 50 Connection mechanism 51 Connecting part 52 Second joint 53 Joint Ribs 54 Filling section 60, 70, 80, 90, 95, 95A Shear reinforcement members 70a hole 81,82 Locking part 92 Protrusion 96 Pedestal 97,97A connecting material A Burial direction C circumferential direction S,V space x-axis

Claims

1. A segment structure comprising a plate forming a wall surface, a joint portion erected at the longitudinal end of the plate, a main girder erected at the short end of the plate, a plurality of steel segments arranged in a ring shape, and a connecting mechanism for connecting adjacent steel segments, wherein multiple ring bodies are arranged radially outward and radially inward, and each is arranged and connected in an axial direction, A reinforcing member is disposed between the radially outer annular body and the radially inner annular body along the axial direction of the segment structure, It comprises a filling portion filled between the radially outer annular body and the radially inner annular body, The segment structure is a foundation structure characterized by comprising a plurality of shear reinforcing members connecting the radially outer annular body and the radially inner annular body.

2. The steel segment comprises a plurality of ribs erected between the longitudinal ends of the plate. The foundation structure according to claim 1, characterized in that the shear reinforcing member connects the opposing ribs of the radially outer annular body and the radially inner annular body.

3. The foundation structure according to claim 1 or 2, characterized in that a plurality of shear reinforcing members are arranged along the axial direction in a single steel segment.

4. The foundation structure according to claim 1 or 2, characterized in that the shear reinforcing member is arranged along the radial direction of the annular body.

5. The shear reinforcement member is formed by folding both ends in a hook shape. The rib of one of the radially outer annular body and the radially inner annular body has a hole for hooking one end of the shear reinforcing member, The foundation structure according to claim 2, characterized in that the rib of the radially outer annular body and the other radially inner annular body has a slit for receiving the other end of the shear reinforcing member and a restricting member for restricting the shear reinforcing member received in the slit.

6. The foundation structure according to claim 2, characterized in that the shear reinforcing member is formed in the shape of a plate, and both ends are connected to the opposing ribs.

7. The foundation structure according to claim 6, characterized in that the shear reinforcement member has a plurality of holes.

8. The shear reinforcement member is formed by folding both ends in a hook shape. The foundation structure according to claim 2, characterized in that each of the ribs of the radially outer annular body and the radially inner annular body has a locking portion for locking the end of the shear reinforcing member.

9. The shear reinforcement member has protrusions at both ends, The foundation structure according to claim 2, characterized in that the ribs of the radially outer annular body and the radially inner annular body each have holes into which the protruding portion is inserted.

10. The foundation structure according to claim 2, characterized in that the shear reinforcing member has a base connected to the ribs of the radially outer annular body and the radially inner annular body, and a connecting member whose ends are fitted into the respective bases.

11. The foundation structure according to claim 2, characterized in that the shear reinforcing member comprises a base connected to one of the radially outer annular body and the radially inner annular body, and a connecting member whose one end is fitted into the base and whose other end is locked to the other rib.

12. The foundation structure according to claim 1, characterized in that at least a portion of the reinforcing member is a main reinforcement bar.

13. The foundation structure according to claim 1, characterized in that at least a portion of the reinforcing member is a structural steel.

14. The foundation structure according to claim 13, characterized in that the shaped steel has irregularities formed on at least a part of its surface.

15. A plurality of steel segments arranged in a ring shape, each having a plate forming a wall surface, a joint portion erected at the longitudinal end of the plate, and a main girder erected at the short end of the plate. An annular body having a connecting mechanism for connecting adjacent steel segments, The annular body is characterized in that the steel segment is provided with a locking portion for a shear reinforcing member that connects to other annular steel segments arranged on the radially outer or radially inner side of the annular body.

16. The steel segment comprises a plurality of ribs erected between the longitudinal ends of the plate. The annular body according to claim 15, characterized in that the locking portion of the shear reinforcing member is provided on the rib.

17. A steel segment having a plate that forms a wall surface, a joint portion erected at the longitudinal end of the plate, and a main girder erected at the short end of the plate, which are connected in a ring shape to form an annular body, A steel segment characterized by having a locking portion for a shear reinforcing member that connects to another steel segment constituting an annular body, which is arranged radially outward or radially inward of the aforementioned annular body.

18. The plate is provided with a plurality of ribs erected between the longitudinal ends of the plate, The steel segment according to claim 17, characterized in that the locking portion of the shear reinforcement member is provided on the rib.

19. A process of connecting multiple steel segments in the longitudinal direction to construct a radially outer annular body and a radially inner annular body, A step of connecting the radially outer annular body and the radially inner annular body with a shear reinforcing member, A step of connecting multiple radially outer annular bodies and radially inner annular bodies connected by the shear reinforcing member along the axial direction of the annular body, The steps include: arranging reinforcing members along the axial direction of the annular body; A method for constructing a foundation structure, comprising the step of filling the space between the radially outer annular body and the radially inner annular body with a filling material.

20. a) A step of connecting multiple steel segments in the longitudinal direction to construct an annular body on the radially outer side, and connecting multiple annular bodies along the axial direction, a) In the space formed inside the radially outer annular body, a plurality of steel segments The process involves connecting them in the longitudinal direction to construct an annular body on the radial side, (c) A step of connecting the radially outer annular body and the radially inner annular body with a shear reinforcing member, The process of repeating steps E) I) and U) to connect all the radially outer annular bodies to the radially inner annular bodies with the shear reinforcing members, (e) A step of arranging reinforcing members along the axial direction of the annular body, (c) A step of filling the space between the radially outer annular body and the radially inner annular body with a filling material, A method for constructing a foundation structure, characterized by having the following features.

21. In the construction of the annular body, the steps include attaching scaffolding to the steel segments, When constructing another annular structure on top of a constructed annular structure, the scaffolding is replaced with steel segments that constitute the other annular structure. A method for constructing a foundation structure according to claim 19 or 20, characterized by having the following:

Images