Roof structure

Abstract

To provide a roof structure capable of improving suppression effect of deformation due to a self-weight of a dome frame while improving bearing force to buckling.SOLUTION: A roof structure 10 comprises: a dome frame 1 disposed along a spherical surface and forming a shape other than a circle in plan view; a ring material 2 disposed below the dome frame 1 and formed in a polygonal annular shape in plan view; and a plurality of tension members 4 connecting the ring material 2 and outer peripheral ends of the dome frame 1. The tension members 4 are sloped so as to gradually go upward as going toward an outer peripheral side.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a roof structure. [Background technology]

[0002] The following Patent Document 1 proposes a dome-shaped roof structure. As shown in Fig. 11 and Fig. 12, the roof structure 100 includes a dome frame 101 arranged along a spherical surface and having a shape other than a circle in a plan view, and a ring material 102 arranged below the dome frame and formed into an annular shape in a plan view. By introducing tension into cable material 103 connecting ring material 102 and outer peripheral material 101c of dome frame 101, this structure makes it possible to suppress bending stress of dome frame 101 and reduce deformation due to its own weight.

[0003] When the dome frame 101 is rectangular in shape, the outer peripheral material 101c at the corners and the vicinity of the corners (hereinafter referred to as "corners") a1 of the dome frame 101 is positioned lower than the outer peripheral material 101c at the side a2. The cable material 103a at the corner a1 is gradually inclined downward toward the outer periphery. Therefore, when tension is applied to the cable material 103a, a downward pulling force (see arrow in Figure 12) is generated on the portion 102a of the ring material 102 located at the corner a1 (hereinafter referred to as "corner ring material"). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-21232 Summary of the Invention [Problem to be solved by the invention]

[0005] Furthermore, when the dome frame 101 is composed of concentric members 101a and radial members 101b, the member density decreases toward the outer periphery, making local buckling more likely to occur in the dome frame 101. When the fixed load is increased, local buckling occurs in the dome frame 101 located directly above the corner ring members 102a.

[0006] In the conventional ring shape, the ring material 102 at the position where local buckling occurs is pulled downward by the cable material 103. When the ring material 102 is not placed, the buckling load magnification λ is λ = 4.37 (buckling occurs at a load 4.37 times the fixed load). Figure 13 shows the first-order buckling eigenvector when the ring material 102 is not placed. When the ring material 102 is placed, the buckling load magnification λ is λ = 4.07. Figure 14 shows the first-order buckling eigenvector when the ring material 102 is placed. As shown by the arrow, it can be seen that local buckling is likely to occur directly above the corner ring material 102a. In other words, there is a problem in that the placement of the ring material 102 reduces the buckling strength (local buckling is more likely to occur).

[0007] Therefore, the present invention has been made in consideration of the above circumstances, and provides a roof structure that can improve the buckling strength while increasing the effect of suppressing deformation due to the weight of the dome frame. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention employs the following means. That is, the roof structure according to the present invention comprises a dome frame arranged along a spherical surface and having a shape other than a circle in a plan view, a ring member arranged below the dome frame and formed into a polygonal ring shape in a plan view, and a plurality of tension members connecting the ring member and the outer peripheral end of the dome frame, the tension members being inclined so as to gradually go upward as they go toward the outer periphery. The dome frame has a rectangular shape in a plan view, and the tension member is connected to the center of a side of the dome frame that forms a rectangle in a plan view. .

[0009] In the roof structure configured in this manner, the tension members are inclined so as to gradually rise upward toward the outer periphery. Therefore, by applying tension to the tension members, the ring members are pulled up by the tension members, and the outer periphery of the dome frame is tightened. The tension members are not connected to the corners of the outer periphery of the dome frame. If the corners of the dome frame and the ring members are connected with tension members (hereinafter referred to as "corner tension members"), the corner tension members will gradually rise downward toward the outer periphery. When tension is applied to the corner tension members, the ring members are pulled down by the corner tension members, and local buckling is likely to occur in the parts of the dome frame directly above the corner ring members (hereinafter referred to as "directly above dome frame"). However, in the above configuration, the corner ring members are not connected to tension members, so that the buckling resistance of the dome frame can be improved. Furthermore, in a dome structure having a rectangular shape in a plan view, it is possible to improve the buckling strength while enhancing the effect of suppressing deformation due to the dome structure's own weight. The tension members are connected to the center of the rectangular side of the dome frame in a plan view. The connection points of the ring members to the tension members are located away from the corners of the dome frame, and the tension members are gradually tilted upward toward the outer periphery. This further improves the buckling strength of the dome frame. Effect of the Invention

[0014] According to the roof structure of the present invention, it is possible to improve the buckling resistance while enhancing the effect of suppressing deformation due to the weight of the dome frame. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view showing a roof structure according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an elevation view showing a roof structure according to one embodiment of the present invention, as viewed from the direction A in FIG. [Diagram 3] FIG. 2 is a plan view illustrating the configuration of a ring material of a roof structure according to one embodiment of the present invention. [Figure 4] 1 shows an analytical model (before changing the shape of the ring material) for verifying the effects of the present invention. [Diagram 5] 1 shows a first buckling eigenvector of a roof structure according to an embodiment of the present invention. [Figure 6] This shows the vertical displacement under fixed load in the case of a roof structure without ring material. [Figure 7]This shows the vertical displacement when a fixed load is applied to a conventional circular ring member. [Figure 8] 4 shows the vertical displacement of a roof structure according to an embodiment of the present invention under fixed load. [Figure 9] FIG. 11 is a plan view illustrating the configuration of a ring material of a roof structure in accordance with a first modified example of an embodiment of the present invention. [Figure 10] FIG. 11 is a plan view illustrating the configuration of a ring material of a roof structure in accordance with a second modified example of an embodiment of the present invention. [Figure 11] FIG. 1 is a perspective view showing a conventional roof structure. [Figure 12] FIG. 1 is an elevation view showing a conventional roof structure. [Figure 13] The primary buckling eigenvector for a roof structure without ring members is shown. [Figure 14] The primary buckling eigenvector for a conventional roof structure (with ring material) is shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] A roof structure according to one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a roof structure according to one embodiment of the present invention. As shown in Fig. 1, the roof structure 10 according to this embodiment includes a dome frame 1, a tension ring material (ring material) 2, a plurality of tension ring bundle materials 3, and a plurality of cable materials (tension materials) 4. The roof structure 10 is a roof structure 10 for a building having a large space, such as an athletic facility.

[0017] In the following description, the center of roof structure 10 is defined as P in plan view. Dome structure 1 is arranged along a spherical surface. Dome structure 1 has an inner ring material 11, multiple circumferential direction members 12, multiple arc members 12a, an outer peripheral member (outer peripheral end portion) 13, multiple radial direction members 14, and multiple diagonal direction members 15. In this embodiment, dome structure 1 is a so-called single-layer dome structure.

[0018] The dome frame 1 has a shape other than a circle in a plan view. In this embodiment, the dome frame 1 has a square shape in a plan view.

[0019] The inner ring material 11 and the multiple circumferential direction members 12 have a circular annular shape centered on a center P in a plan view. The arc material 12a is a part of the circular annular shape centered on the center P in a plan view, that is, has an arc shape.

[0020] The circumferential direction member 12 is disposed outside (radially outward) than the inner circumferential ring material 11. The arc-shaped member 12a is disposed outside (radially outward) than the circumferential direction member 12. The inner circumferential ring material 11, the circumferential direction member 12, and the arc-shaped member 12a are disposed on the same plane (on the same spherical surface). For example, the inner circumferential ring material 11 is configured by connecting members made of H-shaped steel, and the circumferential direction member 12 and the arc-shaped member 12a are configured by connecting a plurality of members made of square tubes.

[0021] The outer peripheral member 13 has a square ring shape centered on the center P in a plan view. The outer peripheral member 13 forms the outer shape of the dome frame 1. For example, the outer peripheral member 13 is formed by connecting multiple members made of H-shaped steel.

[0022] A plurality of inclined pillars 16 are fixed to the outer peripheral member 13. The inclined pillars 16 are installed on a lower structure (not shown).

[0023] The radial members 14 connect the multiple circumferential members 12 and the outer peripheral member 13. The multiple radial members 14 are arranged at intervals in the circumferential direction. A center P is located on an extension line of each radial member 14. In other words, the radial members 14 extend radially. For example, the radial members 14 are configured by connecting multiple members made of square tubes.

[0024] The diagonal direction member 15 connects the inner peripheral ring member 11 and the outer peripheral member 13. The diagonal direction member 15 is formed along a curve. For example, the diagonal direction member 15 is configured by connecting a plurality of members made of square tubes.

[0025] Fig. 2 is an elevational view showing the roof structure 10, as seen from the direction A in Fig. 1. As shown in Fig. 2, the string ring material 2 is disposed below the dome frame 1.

[0026] Fig. 3 is a plan view explaining the configuration of the string ring material 2. Fig. 3 shows only the string ring material 2, the cable material 4, and the outer peripheral material 13, and omits illustration of other components. As shown in Fig. 3, the string ring material 2 is formed in a polygonal ring shape in plan view. In this embodiment, it has an octagonal ring shape centered on center P. In plan view, the string ring material 2 is arranged inside the outer peripheral material 13 of the dome frame 1.

[0027] For example, the string ring material 2 is made up of multiple H-shaped steel members connected together. The string ring material 2 functions as a tension ring and can resist the force (thrust force) that causes the outer peripheral member 13 of the dome frame 1 to expand outward.

[0028] The sides of the peripheral material 13 that form a square in plan view are referred to as peripheral material sides 13a. The short sides 2a of the string ring material 2 that form an octagon in plan view are arranged parallel to the corresponding peripheral material sides 13a. The long sides 2b of the string ring material 2 are arranged so as to connect adjacent short sides 2a. The connection points between the short sides 2a and long sides 2b are referred to as vertices 2c.

[0029] As shown in FIG. 2, the string ring bundle 3 connects the dome frame 1 and the string ring material 2. The string ring bundle 3 extends in the vertical direction. The lower end of the string ring bundle 3 is connected to the apex 2c (see FIG. 3) of the string ring material 2, which is octagonal in plan view, or in the vicinity of the apex 2c. In this embodiment, the number of string ring bundles 3 is eight, corresponding to the number of apexes 2c of the string ring material 2. For example, the string ring bundle 3 is made of a circular steel pipe.

[0030] As shown in Fig. 1, the cable material 4 connects the outer peripheral material 13 of the dome frame 1 to the string ring material 2. As shown in Fig. 3, one end of the cable material 4 is connected to the apex 2c of the string ring material 2. The other end of the cable material 4 is connected to the center of the outer peripheral material side 13a of the outer peripheral material 13. The cable material 4 is not connected to the corner portion 13c of the outer peripheral material 13.

[0031] Two cables 4 are connected to one peripheral member side 13a. The two cables 4 connected to one peripheral member side 13a are arranged so as to gradually become slightly spaced apart from each other from the apex 2c toward the peripheral member side 13a.

[0032] In this embodiment, the number of the cables 4 is eight, corresponding to the number of apexes 2c of the string ring material 2. For example, the cables 4 are made of galvanized steel strands.

[0033] As shown in Fig. 2, the cable material 4 is gradually inclined upward toward the outer periphery (the outer peripheral material 13 side). When tension is applied to the cable material 4, the string ring material 2 is pulled up, and the outer peripheral material 13 is pulled inward (toward the center P). In other words, by applying tension to the cable material 4, the outer peripheral material 13 is pulled.

[0034] In the conventional roof structure of JP 2021-21232 A, the ring material was circular, whereas in this embodiment, the ring material (string ring material 2) is changed to an octagonal ring. Therefore, using the square dome model shown in Figure 4, the effect of improving the buckling resistance and reducing deformation due to its own weight by changing the shape of the ring material is confirmed by analysis.

[0035] The cross-section list of the components of the quadrangular dome model in Figure 4 is shown in Table (1) below.

[0036] [Table 1]

[0037] As shown in Fig. 5, the buckling load factor after changing the shape of the ring material (in the case of the octagonal annular stringed ring material 2 of this embodiment) is λ = 4.50. By adopting the octagonal annular stringed ring material 2 of this embodiment, it can be seen that the buckling strength is improved compared to the buckling load factor λ = 4.37 in the case of no ring material as shown in Fig. 13.

[0038] As shown in Figure 6, when there is no ring material, the vertical displacement of the top of the dome frame when a fixed load is applied is δ = 94.7 mm. As shown in Figure 7, before changing the shape of the ring material (when it is a circular annular ring material), the vertical displacement of the top of the dome frame when a fixed load is applied is δ = 82.1 mm, which is smaller than when there is no ring material (Figure 6), but the pulling down of the cable at the corner causes a maximum deformation of δ = 103 mm directly above the ring at the corner.

[0039] On the other hand, as shown in Figure 8, after changing the shape of the ring material (in the case of the octagonal annular string ring material 2 of this embodiment), the vertical displacement δ at the top of the dome frame under fixed load is 89.0 mm. Because the number of cables has been reduced, the vertical displacement has increased compared to before changing the shape of the ring material (Figure 7). However, compared to when there is no ring material (Figure 6), the displacement has decreased, and no pull-down of the corners has occurred.

[0040] In the roof structure 10 configured in this manner, the cable material 4 is inclined so as to gradually rise upward toward the outer periphery. Therefore, by applying tension to the cable material 4, the string ring material 2 is pulled up by the cable material 4, and the outer periphery material 13 of the dome frame 1 is tightened. The cable material 4 is not connected to the corner 13c of the outer periphery material 13 of the dome frame 1. If the corner 13c of the dome frame 1 and the string ring material 2 are connected by the cable material 4 (referred to as the "corner tensile material"), the corner tensile material will gradually slope downward toward the outer periphery. When tension is applied to the corner tensile material, the ring material is pulled down by the corner tensile material, and local buckling is likely to occur in the part directly above the corner ring material 102a (see FIG. 11) in the dome frame (hereinafter referred to as the "directly above dome frame"). However, in this embodiment, since the cable members 4 are not connected to the corner ring members, the buckling strength of the dome frame 1 can be improved.

[0041] Furthermore, in the dome frame 1 having a square shape in a plan view, the buckling strength can be improved while the effect of suppressing deformation of the dome frame 1 due to its own weight can be increased.

[0042] In addition, the cable material 4 is connected to the center of the peripheral member side 13a of the peripheral member 13 of the dome frame 1. The connection position of the string ring material 2 with the cable material 4 is away from the corner 13c of the dome frame 1, and the cable material 4 gradually slopes upward toward the outer periphery. This further improves the buckling strength of the dome frame 1.

[0043] (Variation 1) Next, a roof structure according to the first modification of the above-described embodiment will be described mainly with reference to FIG. In the following modifications, the same members as those used in the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted.

[0044] As shown in FIG. 9, a roof structure 10A according to this modified example includes a dome frame 1A, a tension ring material (ring material) 2A, a plurality of tension ring bundle materials (not shown), and a plurality of cable materials (tensile materials) 4A.

[0045] The dome frame 1A has a regular octagonal shape centered at center P in plan view. The peripheral member 13A has a regular octagonal ring shape centered at center P in plan view.

[0046] The string ring material 2A has a regular octagonal ring shape centered on center P in plan view.

[0047] The cable material 4A connects the outer peripheral material 13A of the dome frame 1A to the string ring material 2A. One end of the cable material 4A is connected to the apex 2d of the string ring material 2A. The other end of the cable material 4A is connected to the center of the outer peripheral material side 13d of the outer peripheral material 13A. The cable material 4A is not connected to the corner 13e of the outer peripheral material 13A. The cable material 4A is arranged on a straight line passing through the center P and the apex 2d.

[0048] One cable material 4A is connected to one peripheral material side 13d. The cable material 4A is inclined so as to gradually rise upward toward the outer peripheral side (the peripheral material 13A side). When tension is applied to the cable material 4A, the string ring material 2A is pulled up, and the peripheral material 13A is pulled inward (toward the center P). In other words, by applying tension to the cable material 4A, the peripheral material 13A is tightened.

[0049] In the roof structure 10A thus constructed, the cable material 4A is inclined so as to gradually rise upward toward the outer periphery. Therefore, by applying tension to the cable material 4A, the string ring material 2A is pulled up by the cable material 4A, and the outer periphery material 13A of the dome frame 1A is tightened. The cable material 4A is not connected to the corner 13e of the outer periphery material 13A of the dome frame 1A. If the corner 13e of the dome frame 1A and the string ring material 2A are connected by the cable material 4A (referred to as the "corner tensile material"), the corner tensile material will gradually slope downward toward the outer periphery. When tension is applied to the corner tensile material, the ring material is pulled down by the corner tensile material, and local buckling is likely to occur in the part of the dome frame directly above the corner ring material (hereinafter referred to as the "directly above dome frame"). However, in this embodiment, since the cable members 4A are not connected to the corner ring members, the buckling strength of the dome frame 1A can be improved.

[0050] (Variation 2) Next, a roof structure according to Modification 2 of the above-described embodiment will be described mainly with reference to FIG.

[0051] As shown in FIG. 10, a roof structure 10B according to this modified example includes a dome frame 1B, a tension ring material (ring material) 2B, a plurality of tension ring bundle materials (not shown), and a plurality of cable materials (tensile materials) 4B.

[0052] The dome frame 1B has an equilateral triangle shape centered on center P in plan view. The outer peripheral member 13B has an equilateral triangular ring shape centered on center P in plan view.

[0053] The string ring material 2B has a regular hexagonal ring shape centered on center P in plan view.

[0054] The cable material 4B connects the outer peripheral material 13B of the dome frame 1B to the string ring material 2B. One end of the cable material 4B is connected to the apex 2e of the string ring material 2B. The other end of the cable material 4B is connected to the center of the outer peripheral material side 13f of the outer peripheral material 13B. The cable material 4B is not connected to the corner 13g of the outer peripheral material 13B. The cable material 4B is arranged on a straight line passing through the center P and the apex 2e.

[0055] Two cable materials 4B are connected to one peripheral member side 13f. The two cable materials 4B connected to one peripheral member side 13f are arranged so that they gradually become slightly spaced apart from each other as they move from the apex 2e toward the peripheral member side 13f. The cable material 4B is inclined so that it gradually moves upward as it moves toward the outer periphery side (the peripheral member 13B side). When tension is applied to the cable material 4B, the string ring material 2B is pulled up and the peripheral member 13B is pulled inward (toward the center P). In other words, by applying tension to the cable material 4B, the peripheral member 13B is tightened.

[0056] In the roof structure 10B configured in this manner, the cable material 4B is inclined so as to gradually rise upward toward the outer periphery. Therefore, by applying tension to the cable material 4B, the string ring material 2B is pulled up by the cable material 4B, and the outer periphery material 13B of the dome frame 1B is tightened. The cable material 4B is not connected to the corner 13g of the outer periphery material 13B of the dome frame 1B. If the corner 13g of the dome frame 1B and the string ring material 2B are connected by the cable material 4B (referred to as the "corner tensile material"), the corner tensile material will gradually slope downward toward the outer periphery. When tension is applied to the corner tensile material, the ring material is pulled down by the corner tensile material, and local buckling is likely to occur in the part of the dome frame directly above the corner ring material (hereinafter referred to as the "directly above dome frame"). However, in this embodiment, since the cable members 4B are not connected to the corner ring members, the buckling strength of the dome frame 1B can be improved.

[0057] The shapes and combinations of the components shown in the above-described embodiment are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0058] For example, in the embodiment described above, the dome frame 1 is square in plan view, but the present invention is not limited to this. The dome frame 1 may be any shape other than circular in plan view, such as a triangle, a rectangle, a polygon, or an ellipse.

[0059] In the embodiment described above, the string ring material 2 has an octagonal ring shape in plan view, but the present invention is not limited to this. The string ring material 2 may have any polygonal ring shape in plan view, such as a triangle, a square, or a pentagon. [Explanation of symbols]

[0060] 1...Dome structure 2...String ring material (ring material) 4...Cable material (tensile material) 10…Roof structure

Claims

[Claim 1] A dome structure that is arranged along a sphere and has a shape other than a circle in plan view; A ring material is disposed below the dome frame and formed into a polygonal ring shape in a plan view; A plurality of tension members connecting the ring member and the outer peripheral end portion of the dome frame, The tension member is inclined so as to gradually rise upward toward the outer periphery, The dome frame has a rectangular shape in a plan view, A roof structure in which the tension member is connected to the center of a side that forms a rectangle in a plan view of the dome frame.

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