Basic Construction

Abstract

To provide a foundation structure that can realize supporting one pillar with two piles.SOLUTION: Four diagonal members 7 are provided correspondingly to each of four small beams 24 and extend diagonally downward from the small beams 24 to a first cylindrical body 4, perpendicularly to a parallel direction of two piles 2. A bolt 36 is inserted into a long hole 7c extending in a vertical direction at an upper end 7a of the diagonal member 7 and into a through hole 31a of a gusset plate 31, and thus the diagonal member 7 and the small beam 24 are connected via the gusset plate 31. A bolt 36 is inserted into a long hole 7c extending in a vertical direction at a lower end 7b of the diagonal member 7 and into a through hole 32a of the gusset plate 32, and thus the diagonal member 7 and the first cylindrical body 4 are connected via the gusset plate 32.SELECTED DRAWING: Figure 2

Description

Technical Field

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[0001] The present invention relates to a foundation structure for supporting structures such as buildings.

Background Art

[0002] As a foundation structure for supporting structures such as buildings, Patent Document 1 discloses a structure for joining a foundation beam and a pile, which includes a first cylindrical body joined to the foundation beam, a second cylindrical body that surrounds the periphery of the head of the pile installed in the ground and surrounds all or part of the periphery of the first cylindrical body below the upper end of the first cylindrical body, and concrete filled inside the first and second cylindrical bodies.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technology of Patent Document 1 supports one column with one pile, but there has been a need for a foundation structure that supports one column with two piles in cases where the weight of the structure is large.

[0005] In view of the above, the present invention is made, and an object thereof is to provide a foundation structure capable of supporting one column with two piles.

Means for Solving the Problems

[0006] To achieve the above objective, the foundation structure of the present invention comprises a foundation beam having a column positioned between two piles installed in the ground, two first beams joined to the column in the parallel direction of the two piles and extending in the parallel direction, and four second beams positioned on one side and the other side of each of the two piles in a direction perpendicular to the parallel direction and extending in the parallel direction, two first cylindrical bodies extending in the vertical direction and joined to the two first beams respectively, and a structure extending in the vertical direction around the heads of each of the two piles. Two second cylindrical bodies surround the lower ends of each of the two first cylindrical bodies, a first concrete filling the interior of one of the two first cylindrical bodies and the interior of one of the two second cylindrical bodies, a second concrete filling the interior of the other first cylindrical body and the interior of the other second cylindrical body, and provided corresponding to each of the four second beams, perpendicular to the parallel direction, extending from the second beams to the first cylindrical body or the second cylindrical body The structure comprises four diagonal members extending diagonally downward to the body, each of the four second beams being provided with a first connecting member, each of the two first cylindrical bodies or the two second cylindrical bodies being provided with two second connecting members, and through holes are formed in one end and the other end of the first connecting member, the second connecting member, and the diagonal members and the second beams are connected via the first connecting member by inserting a pin through the through hole in one end of the diagonal member and the through hole in the first connecting member. The diagonal member and the first cylindrical body or the second cylindrical body are connected via the second connecting member by inserting a pin through the through hole at the other end of the diagonal member and the through hole at the second connecting member, wherein at least one of the through hole at the first connecting member and the through hole at one end of the diagonal member is an elongated hole extending in the vertical direction, and at least one of the through hole at the second connecting member and the through hole at the other end of the diagonal member is an elongated hole extending in the vertical direction. [Effects of the Invention]

[0007] According to the foundation structure of the present invention, it is possible to support one column with two piles. [Brief explanation of the drawing]

[0008] [Figure 1] This is a plan view showing the basic structure according to the embodiment. [Figure 2] This is a cross-sectional view along line AA in Figure 1. [Figure 3] This diagram shows the state of the diagonal bracing under normal conditions. [Figure 4] This diagram shows the state of the diagonal member when the first cylindrical body is tilted in the opposite direction to the diagonal member. [Figure 5] This diagram shows the state of the diagonal member when the first cylindrical body is tilted towards the diagonal member. [Figure 6] This diagram illustrates the distance between the central axes of the bolts at the upper and lower ends of the diagonal brace. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings. Throughout the drawings, the same or equivalent parts and components are denoted by the same or equivalent reference numerals.

[0010] The embodiments shown below illustrate devices and the like that embody the technical concept of this invention, and the technical concept of this invention does not limit the materials, shapes, structures, arrangements, etc. of each component to those described below. The technical concept of this invention can be modified in various ways within the scope of the claims.

[0011] Figure 1 is a plan view showing a basic structure according to an embodiment of the present invention. Figure 2 is a cross-sectional view along line AA in Figure 1. In the following description, the direction perpendicular to the plane of the paper in Figure 1 is defined as the up-down direction, and the direction of the front of the paper is defined as the up direction. The up-down direction is the vertical direction. Also, the front, back, left, and right directions indicated by the arrows in Figure 1 are defined as the front-back, left, and right directions. The left-right direction and the front-back direction are perpendicular to each other, and both are perpendicular to the up-down direction and parallel to the horizontal direction.

[0012] As shown in Figures 1 and 2, the foundation structure 1 according to this embodiment comprises two piles 2, a foundation beam 3, two first cylindrical bodies 4, two second cylindrical bodies 5, two concrete 6, and four diagonal members 7.

[0013] The two piles 2 are installed in the ground 8 spaced apart from each other in the left-right direction (corresponding to the parallel direction). The piles 2 are formed in a cylindrical shape that extends in the vertical direction. The piles 2 are installed with their heads 2a protruding upward from the lean concrete 9 formed on the ground 8. The piles 2 may be cast-in-place piles or precast piles.

[0014] The foundation beam 3 supports the columns 11 of a building or other structure. The columns 11 are positioned between two piles 2 in the left-right direction. A slab 12 is placed on top of the foundation beam 3. Note that the slab 12 is not shown in Figure 1.

[0015] The foundation beam 3 comprises two main beams 21 (corresponding to the first beam) extending in the left-right direction, two main beams 22 (corresponding to the third beam) extending in the front-back direction, four secondary beams 23 (corresponding to the fourth beam) extending in the front-back direction, and four secondary beams 24 (corresponding to the second beam) extending in the left-right direction.

[0016] The two main beams 21 are joined to the column 11, flanking it in the left-right direction. The left main beam 21 is positioned on the central axis of the left pile 2. The left main beam 21 is joined to the lower end of the left side surface of the column 11. The right main beam 21 is positioned on the central axis of the right pile 2. The right main beam 21 is joined to the lower end of the right side surface of the column 11.

[0017] The two main beams 22 are joined to the column 11 in the front-to-back direction, with the column 11 in between. The front main beam 22 is joined to the lower end of the front side surface of the column 11. The rear main beam 22 is joined to the lower end of the rear side surface of the column 11.

[0018] The girders 21, 22 are made of H-shaped steel. The girders 21, 22 are arranged such that their respective flanges 21a, 22a are horizontal.

[0019] The four small beams 23 are joined one by one to each of the four small beams 24 and are also joined to each of the two girders 21, sandwiching each of the two girders 21 in the front-rear direction. That is, two of the four small beams 23 are joined to the left girder 21, and the remaining two small beams 23 are joined to the right girder 21. And the small beams 23 joined to the left girder 21 are arranged one by one on the front side and the rear side of the left girder 21 on the left side of the girder 22. Also, the small beams 23 joined to the right girder 21 are arranged one by one on the front side and the rear side of the right girder 21 on the right side of the girder 22.

[0020] The small beam 23 is made of H-shaped steel. The small beam 23 is arranged such that the flange 23a is horizontal.

[0021] The small beam 24 is a beam that connects the girder 22 and the small beam 23. Two of the four small beams 24 are joined to the front girder 22, sandwiching the front girder 22, and the remaining two small beams 24 are joined to the rear girder 22, sandwiching the rear girder 22. As a result, the small beams 24 are arranged one by one on the front side of the left girder 21, the rear side of the left girder 21, the front side of the right girder 21, and the rear side of the right girder 21. In other words, the small beams 24 are arranged one by one on the front side (one side) and the rear side (the other side) of each of the two piles 2.

[0022] The small beam 24 is made of H-shaped steel. The small beam 24 is arranged such that the web 24b is horizontal. And the space on the web 24b of the small beam 24 is filled with the slab 12. That is, the space defined by the web 24b of the small beam 24 and the upper part from the webs 24b of the two flanges 24a is filled with the slab 12.

[0023] Each of the four joists 24 is provided with a gusset plate 31 (corresponding to the first connecting member). The gusset plate 31 is for connecting the joist 24 to the diagonal member 7. The gusset plate 31 is erected on the flange 24a on the pile 2 side (first cylindrical body 4 side) of the two flanges 24a of the joist 24. That is, on the joist 24 in front of the pile 2, the gusset plate 31 is erected on the rear flange 24a. On the joist 24 behind the pile 2, the gusset plate 31 is erected on the front flange 24a.

[0024] The gusset plate 31 has a through hole 31a through which a bolt (equivalent to a pin) 36, described later, is inserted. The through hole 31a has a diameter slightly larger than the bolt 36 and does not allow the bolt 36 to move relative to the gusset plate 31.

[0025] The first cylindrical body 4 consists of a cylindrical steel pipe extending in the vertical direction. Two first cylindrical bodies 4 are joined to two main beams 21, respectively. The first cylindrical body 4 is formed by joining two half-pipes to the main beams 21 at their upper parts and joining them to each other at their lower parts. The first cylindrical body 4 is positioned so that its central axis coincides with the central axis of the pile 2. The upper end of the first cylindrical body 4 is at the same height as the upper surface of the flange 21a of the main beam 21 and the upper surface of the 22a of the main beam 22. The lower end of the first cylindrical body 4 is above the upper end of the pile 2.

[0026] Each of the two first cylindrical bodies 4 is provided with two gusset plates 32 (corresponding to the second connecting member). The gusset plates 32 are for connecting the first cylindrical body 4 to the diagonal member 7. The two gusset plates 32 provided on the first cylindrical body 4 are erected on the outer circumference of the first cylindrical body 4, sandwiching the first cylindrical body 4, along the center line of the first cylindrical body 4 in the front-rear direction. In the vertical direction, the gusset plates 32 are positioned lower than gusset plate 31 but higher than the upper end of the second cylindrical body 5.

[0027] The gusset plate 32 has a through hole 32a through which a bolt (equivalent to a pin) 36, described later, is inserted. The through hole 32a has a diameter slightly larger than the bolt 36 and does not allow the bolt 36 to move relative to the gusset plate 32.

[0028] The second cylindrical body 5 is made of a cylindrical steel pipe extending in the vertical direction. The second cylindrical body 5 is placed on the lean concrete 9. The two second cylindrical bodies 5 surround the entire circumference of the heads 2a of each of the two piles 2, spaced apart from the heads 2a. The two second cylindrical bodies 5 also surround the entire circumference of the lower ends 4a of each of the two first cylindrical bodies 4, spaced apart from the lower ends 4a. The second cylindrical body 5 is positioned so that its central axis coincides with the central axis of the pile 2 and the central axis of the first cylindrical body 4. Preferably, the steel pipe forming the second cylindrical body 5 has the same thickness as the steel pipe forming the first cylindrical body 4, and has a larger inner and outer diameter than the steel pipe forming the first cylindrical body 4.

[0029] One of the two concretes 6 (corresponding to the first or second concrete) is filled inside the first cylindrical body 4 on the left and the second cylindrical body 5 on the left. The other concrete 6 (corresponding to the second or first concrete) is filled inside the first cylindrical body 4 on the right and the second cylindrical body 5 on the right.

[0030] As a result, the left-side first cylindrical body 4 and the left-side second cylindrical body 5 are integrated with each other via the left-side concrete 6, and the left-side first cylindrical body 4 and the left-side second cylindrical body 5 and the left-side pile 2 are integrated with each other via the left-side concrete 6. Furthermore, the left-side main beam 21 and the left-side first cylindrical body 4 and the left-side second cylindrical body 5 are integrated with each other via the left-side concrete 6. Also, the right-side first cylindrical body 4 and the right-side second cylindrical body 5 are integrated with each other via the right-side concrete 6, and the right-side first cylindrical body 4 and the right-side second cylindrical body 5 and the right-side pile 2 are integrated with each other via the right-side concrete 6. Furthermore, the right-side main beam 21 and the right-side first cylindrical body 4 and the right-side second cylindrical body 5 are integrated with each other via the right-side concrete 6.

[0031] The diagonal members 7 are members that extend diagonally downward from the beams 24 to the first cylindrical body, perpendicular to the parallel direction of the two piles 2, along the front-to-back direction. The four diagonal members 7 are provided corresponding to each of the four beams 24. The angle of the direction in which the diagonal members 7 extend with respect to the vertical direction can be, for example, 45 degrees.

[0032] The upper end (corresponding to one end) 7a and the lower end (corresponding to the other end) 7b of the diagonal member 7 each have elongated holes 7c that extend in the vertical direction.

[0033] The diagonal member 7 and the secondary beam 24 are connected via the gusset plate 31 by inserting bolts 36 through the elongated hole 7c in the upper end 7a of the diagonal member 7 and the through hole 31a of the gusset plate 31.

[0034] The diagonal member 7 and the first cylindrical body 4 are connected via the gusset plate 32 by inserting a bolt 36 through the elongated hole 7c in the lower end 7b of the diagonal member 7 and the through hole 32a in the gusset plate 32.

[0035] A nut (not shown) is screwed onto the bolt 36 to prevent it from falling out, but the diagonal member 7 and the gusset plates 31 and 32 are not fixed together, and vertical movement of the diagonal member 7 relative to the bolt 36 is permitted by the elongated hole 7c.

[0036] In this embodiment, the diagonal member 7 is formed by two channel steel sections 41 connected to the gusset plates 31 and 32, with the gusset plates 31 and 32 in between.

[0037] Next, we will explain the function of basic structure 1.

[0038] Under normal conditions without earthquakes, as shown in Figure 3, the diagonal member 7, due to its own weight, has bolts 36 at the upper end 7a and lower end 7b where they are located at the upper end of the elongated holes 7c. Note that Figure 3 shows the front diagonal member 7. The same applies to Figures 4 and 5, which will be described later.

[0039] Here, let L be the distance between the central axes of the upper end bolt 36 and the lower end bolt 36 of the diagonal member 7 in the front-rear direction. Also, let d1 be the distance between the central axes of the upper end bolt 36 and the lower end bolt 36 of the diagonal member 7 under normal conditions.

[0040] When an earthquake occurs, if the top 2a of the pile 2 rotates with the left-right axis of rotation (oscillating in the front-back direction), the first cylindrical body 4 and the second cylindrical body 5 and the pile 2 are integrated with each other via concrete 6, so the first cylindrical body 4 and the second cylindrical body 5 will also rotate.

[0041] Due to this rotation, if the first cylindrical body 4 tilts in the opposite direction to the diagonal member 7 in the front-rear direction, that is, if the first cylindrical body 4 tilts to the rearward side in the case of the front diagonal member 7 shown in Figure 3, the upper end of the diagonal member 7 rises, as shown in Figure 4.

[0042] Here, as shown in Figure 4, when the upper end of the diagonal member 7 rises, and the bolt 36 is at the lower end of the elongated hole 7c at the upper end 7a, and the bolt 36 is at the upper end of the elongated hole 7c at the lower end 7b, let d2 be the distance between the central axes of the bolt 36 on the upper end and the bolt 36 on the lower end of the diagonal member 7.

[0043] On the other hand, in each diagonal member 7, if the first cylindrical body 4 is tilted toward the diagonal member 7 in the front-rear direction, that is, if the first cylindrical body 4 is tilted toward the front in the case of the front diagonal member 7 shown in Figure 3, the lower end of the diagonal member 7 rises, as shown in Figure 5.

[0044] Here, as shown in Figure 5, when the lower end of the diagonal member 7 rises, and the bolt 36 is at the upper end of the elongated hole 7c at the upper end 7a and at the lower end 7b, the distance between the central axes of the bolt 36 on the upper end and the bolt 36 on the lower end of the diagonal member 7 is denoted as d3.

[0045] As shown in Fig. 6, the above distances d1 to d3 are in the relationship of d2 < d1 < d3. Due to the rotation of the first cylindrical body 4 and the second cylindrical body 5, the distance between the central axes of the bolts 36 on the upper end side and the lower end side of the diagonal member 7 changes. On the other hand, since the rotation angle θ of the first cylindrical body 4 and the second cylindrical body 5 due to an earthquake is minute, the distance L between the bolts 36 in the front-rear direction can be regarded as constant.

[0046] Therefore, while allowing rotation about the left-right direction, which is the parallel direction of the two piles 2, as the rotation axis, the piles 2, the first cylindrical body 4, and the second cylindrical body 5 can be restrained in the front-rear direction to suppress movement. That is, in the front-rear direction, while avoiding the transmission of the bending moment between the foundation beam 3 and the head 2a of the pile 2, the shear force can be transmitted.

[0047] Here, the foundation structure 1 is a structure capable of transmitting the bending moment and the shear force between the foundation beam 3 and the head 2a of the pile 2 in the left-right direction, which is the parallel direction of the two piles 2.

[0048] On the other hand, in the front-rear direction, since it is the weak axis direction of the large beam 21, it is difficult to transmit the bending moment between the foundation beam 3 and the head 2a of the pile 2. If it is attempted to transmit the bending moment between the foundation beam 3 and the head 2a of the pile 2 in the front-rear direction as well as in the left-right direction, an auxiliary beam or the like using a large cross-section steel skeleton is required, which is difficult to achieve.

[0049] In contrast, in the foundation structure 1, as described above, by providing the diagonal member 7, while avoiding the transmission of the bending moment between the foundation beam 3 and the head 2a of the pile 2 in the weak axis direction (front-rear direction) of the large beam 21, the shear force can be transmitted. For this reason, rotation mainly caused by the shear force can be suppressed, and lateral buckling can also be suppressed.

[0050] Thereby, according to the foundation structure 1, even if the large beam 21 is installed such that the front-rear direction orthogonal to the parallel direction of the two piles 2 becomes the weak axis direction, it is possible to realize supporting one column 11 with two piles 2.

[0051] Furthermore, in the foundation structure 1, the secondary beams 24 to which the diagonal members 7 are connected are positioned so that the webs 24b are horizontal. By making the strong axis direction of the secondary beams 24 the front-to-back direction, the restraining force on the piles 2, the first cylindrical body 4, and the second cylindrical body 5 in the front-to-back direction can be increased.

[0052] Furthermore, in the foundation structure 1, the space above the web 24b of the secondary beam 24 is filled with the slab 12. As a result, the secondary beam 24 is constrained by the slab 12, which further increases the restraining force on the pile 2, the first cylindrical body 4, and the second cylindrical body 5 in the front-rear direction.

[0053] In the above-described embodiment, the through-hole provided in the diagonal member 7 was assumed to be an elongated hole 7c. However, the through-hole provided in the diagonal member 7 may not be an elongated hole, and the through-holes provided in the gusset plates 31 and 32 may be elongated holes extending in the vertical direction. Furthermore, both the through-hole in the diagonal member 7 and the through-holes in the gusset plates 31 and 32 may be elongated holes extending in the vertical direction.

[0054] Furthermore, in the above-described embodiment, a configuration was described in which the diagonal member 7 and the first cylindrical body 4 are connected via a gusset plate 32. However, a configuration in which the gusset plate 32 is provided on the second cylindrical body 5 and the diagonal member 7 and the second cylindrical body 5 are connected via the gusset plate 32 is also possible.

[0055] Furthermore, in the above-described embodiment, the diagonal member 7 and the gusset plates 31 and 32 were connected by bolts 36, but the invention is not limited to this, and pins other than bolts may also be used.

[0056] Furthermore, although the above-described embodiment described a configuration in which the main beam 21 is installed such that the direction perpendicular to the parallel direction of the two piles 2 (front-to-back direction) is the weak axis direction, the present invention is also applicable when the main beam 21 is installed such that the strong axis direction is the front-to-back direction.

[0057] Furthermore, in the embodiment described above, the diagonal member 7 consists of two channel steel sections 41, but it is not limited to this, and may also be a single channel steel section, an H-beam, an I-beam, a T-beam, an angle steel section, a flat steel section, or a combination thereof.

[0058] Furthermore, in the embodiment described above, the secondary beam 24 was positioned so that the web 24b was horizontal, but it may also be positioned so that the flange 24a was horizontal.

[0059] The present invention is not limited to the embodiments described above, and the components can be modified and implemented in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiments. Moreover, components from different embodiments may be appropriately combined. [Explanation of symbols]

[0060] 1 Basic structure 2 stakes 3 Foundation beam 4. First cylindrical body 5. Second cylindrical body 6. Concrete 7 Diagonal 7a Upper end 7b Bottom end 7c long hole 8 Ground 9. Lean concrete 11 pillars 12 Slabs 21,22 Large beam 23,24 Small beam 21a, 22a, 23a, 24a flange 24b Web 31, 32 Gusset Plate 31a,32a through hole 36 volts 41 Channel steel

Claims

1. A foundation beam having a column positioned between two piles installed in the ground, two first beams joined to the column in the parallel direction of the two piles and extending in the parallel direction, and four second beams positioned on one side and the other side of each of the two piles in a direction perpendicular to the parallel direction and extending in the parallel direction, Two first cylindrical bodies extending in the vertical direction and joined to the two first beams, Two second cylindrical bodies extending in the vertical direction, surrounding the heads of each of the two piles, and surrounding the lower ends of each of the two first cylindrical bodies, The first concrete is filled inside one of the two first cylindrical bodies and inside one of the two second cylindrical bodies, The second concrete filled inside the other first cylindrical body and the other second cylindrical body, It comprises four diagonal members provided corresponding to each of the four second beams, which are perpendicular to the parallel direction and extend diagonally downward from the second beam to the first cylindrical body or the second cylindrical body, Each of the four second beams is provided with a first connecting member. Each of the two first cylindrical bodies or the two second cylindrical bodies is provided with two second connecting members. Through holes are formed in the first connecting member, the second connecting member, and one end and the other end of the diagonal member, The diagonal member and the second beam are connected via the first connecting member by inserting a pin through the through hole in one end of the diagonal member and the through hole in the first connecting member. The diagonal member and the first cylindrical body or the second cylindrical body are connected via the second connecting member by inserting a pin through the through hole at the other end of the diagonal member and the through hole in the second connecting member. At least one of the through-holes in the first connecting member and the through-holes in one end of the diagonal member is an elongated hole extending in the vertical direction. The foundation structure is characterized in that at least one of the through-holes in the second connecting member and the through-holes in the other end of the diagonal member is an elongated hole extending in the vertical direction.

2. The foundation structure according to claim 1, characterized in that the second beam is formed of H-shaped steel arranged so that its web is horizontal.

3. A slab is placed on the aforementioned foundation beam. The foundation structure according to claim 2, characterized in that the space on the web of the H-shaped steel forming the second beam is filled with the slab.

4. The foundation beam further comprises two third beams that are joined to the columns in a direction perpendicular to the parallel direction, with the columns in between, and extending in a direction perpendicular to the parallel direction. The foundation structure according to any one of claims 1 to 3, characterized in that two of the four second beams are joined to one of the two third beams, with the other third beam in between, and the remaining two second beams are joined to the other third beam, with the other third beam in between.

5. The foundation beam further comprises four fourth beams extending in a direction perpendicular to the parallel direction, The foundation structure according to any one of claims 1 to 3, characterized in that two of the four fourth beams are joined to one of the two first beams, sandwiching one of the first beams, the remaining two fourth beams are joined to the other first beam, sandwiching the other first beam, and one of the four fourth beams is joined to each of the four second beams.

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