JP2014088737A - Method for deriving structural characteristic coefficient curve and method for determining structural characteristic coefficient using structural characteristic coefficient curve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for deriving a structural characteristic coefficient curve used to find structural characteristic coefficients of various dome-shaped structures differing scale when making an aseismatic design employing the structural characteristic coefficient.SOLUTION: A method for deriving a structural characteristic coefficient includes the steps of: forming a joint part 62 for experiment; carrying out an intensity experiment on the joint part 62 for experiment so as to obtain various joint part elements; calculating a structural characteristic coefficient (frame coefficient) of a unit member 60 from the member length and various joint part elements with respect to the unit member 60; calculating a Ds value of each layer structure part S of a dome-shaped structure 10 assumed to comprise unit members 60 having respective frame coefficients; plotting frame coefficients calculated by member lengths of each unit member 60 and Ds values corresponding to the frame coefficients on a two-dimensional plane; and obtaining a structural characteristic coefficient curve of each layer structure part S based upon respective plotted points.

Description

  The present invention relates to a method for deriving a structural characteristic coefficient curve used to obtain a structural characteristic coefficient of a dome-shaped structure formed in a dome shape, and to determine the structural characteristic coefficient of the dome-shaped structure using the structural characteristic coefficient curve. The present invention relates to a method for determining structural characteristic coefficients.

  Conventionally, as a dome-like structure having a substantially hemispherical appearance, there is a dome called a geodesic dome (or fuller dome). Specifically, for example, a plurality of triangular structures formed of three frame members are three-dimensionally connected without gaps so as to have a substantially hemispherical shape (dome shape). By being formed in this manner, even if the frame member is made of wood, the frame member exhibits sufficient strength and can be made extremely light. Thereby, the dome-like structure can ensure the excellent earthquake resistance and wind resistance which do not easily collapse even in disasters such as earthquakes and typhoons.

Conventionally, dome-shaped structures have been used for relatively large buildings for the purpose of use such as exhibition halls, but in recent years, the demand for small general houses with a compact structure has increased (for example, Patent Document 1).
By the way, when designing a house, it is necessary to perform an earthquake-resistant design specified in the Building Standard Law. When performing seismic design in response to a large earthquake, etc., the required horizontal proof stress is calculated based on the structural characteristic coefficient necessary for this calculation. Therefore, when performing seismic design in response to a large earthquake or the like, the seismic design can be performed by determining the structural characteristic coefficient.

  Here, the above-mentioned dome-shaped structure is a house that varies in accordance with the desire of the inhabitants of the dome-shaped structure such as the number of floors, the height, and the diameter of the dome.

Japanese Patent Laid-Open No. 7-18744

  When a structural characteristic coefficient is determined for each house with a different scale of this dome-shaped structure, and an earthquake-resistant design is performed based on this structural characteristic coefficient, it will sufficiently respond to large earthquakes etc. stipulated by the Building Standards Act Can do. However, conducting a strength experiment on the members used for each dome-shaped structure of different scale, and determining the structural characteristic coefficient by performing a high-accuracy calculation based on the experimental results requires enormous costs and time. There is a first problem that it is not possible to inquire economically and economically.

In addition, since various variation factors are included in the earthquake-resistant design, it is not economical to determine the structural characteristic coefficient in which various variation factors are individually changed in the design process. However, there is a second problem that safety against a large earthquake cannot be sufficiently ensured unless the influence of each variation factor is reflected in the process of determining the structural characteristic coefficient.
The invention described in claim 1 has been made in view of the first problem of the prior art described above, and the object of the invention is to perform various seismic design using the structural characteristic coefficient. It is an object of the present invention to provide a method for deriving a structure characteristic coefficient curve used for obtaining a structure characteristic coefficient of dome-shaped structures of different scales.

The invention described in claim 2 has been made in view of the second problem of the prior art described above. In addition to the object of the invention described in claim 1, the seismic design of the dome-shaped structure is provided. An object of the present invention is to provide a method for deriving a structural characteristic coefficient curve used for obtaining a structural characteristic coefficient of a dome-like structure standing on a safer side.
The invention described in claim 3 has been made in view of the second problem of the above-described prior art, and in addition to the object of the invention described in claim 1 or 2, it is more safe. An object is to provide a method for deriving a structural characteristic coefficient curve of a standing dome-like structure.

  The invention according to claim 4 determines the structural characteristic coefficient of the dome-shaped structure, which can easily determine the structural characteristic coefficient of various dome-shaped structures of various scales when performing seismic design employing the structural characteristic coefficient. It aims to provide a method.

(Claim 1)
The invention according to claim 1 is a hierarchy in which a plurality of triangular structures 40 inscribed in the same sphere are provided, and layer structures S formed in an annular shape by stacking the triangular structures 40 without gaps are stacked. This is a method for deriving the structural characteristic coefficient curve used to obtain the structural characteristic coefficient necessary for the design stipulated in the Building Standards Act for each of the layer structure parts S when performing the seismic design of the dome-shaped structure 10 having a structure. The triangular structure 40 is provided at a position where the frame member 50 is provided at a position corresponding to each side of the triangle, and at a position where the vertexes of the triangles are gathered to connect the frame members 50 to each other. The connector 71 is provided with a joining piece 77 to which the end of the frame member 50 is joined, and in front of the end of the experimental frame member 51 having a predetermined material and cross-sectional shape. A step of forming an experimental joint 62 in which the joint piece 77 independent from the connector 71 is joined, and a strength experiment is performed on the experimental joint 62 to determine ultimate strength, rigidity and plasticity ratio (hereinafter referred to as “joint”). And the unit member 60 on the assumption that the experimental frame member 51 has a predetermined member length and the experimental joint 62 is joined to both ends thereof. A step of calculating a structural characteristic coefficient (hereinafter referred to as “frame coefficient”) of the unit member 60 from the member length and the joint specifications, and the unit member 60 having the frame coefficients. A step of calculating a structural characteristic coefficient (hereinafter referred to as “Ds value”) of each layer structure portion S of the assumed dome-shaped structure 10, and the unit length calculated for each member length of each unit member 60. Frame factor and this frame factor And the step of plotting the Ds values corresponding to the two-dimensional plane, and the step of obtaining the structure characteristic coefficient curve of each layer structure portion S based on the plotted points.

Here, the “dome-shaped structure 10” means a so-called geodesic dome or a dome-shaped structure called a fuller dome.
Further, the “frame member 50” is a skeleton of the dome-shaped structure 10 and is provided at a position corresponding to each side of each triangular structure 40 constituting the dome-shaped structure 10. It is.

The “connector 71” connects the ends of the frame member 50, and is provided at a position where the apexes of the triangular structures 40 constituting the dome-shaped structure 10 gather. is there.
Here, it is described as “hierarchical structure in which layer structure portions S formed in an annular shape are stacked” and “determining a structural characteristic coefficient for each layer structure portion S”. Specifically, the “layer structure portion S” is, for example, the first structure portion 11, the second structure portion 12, the third structure portion 13, the fourth structure portion 14, and the fifth structure portion from above the dome-shaped structure 10. There are 15. Then, the Ds value is calculated for the first floor layer composed of one layer structure portion S of only the fifth structure portion 15, and the four layer structure portions S from the fourth structure portion 14 to the first structure portion 11 are integrated. The Ds value for the second floor layer is calculated.

  Further, the “joining piece 77” of the experimental joining portion 62 is not actually separated from the actual connector 71 by cutting or the like. That is, as an independent part from the connector 71 at the end of the experimental frame member 51 in order to reproduce the same joint state between the actual connector 71 and the frame member 50 for the experiment of the experimental joint portion 62. It is what is formed.

  In the present invention, a strength experiment of the experimental joint 62 is performed, and joint specifications such as a plastic modulus of the experimental joint 62 are obtained based on the experimental result. For the unit member 60 that is assumed that the experimental frame member 51 has a predetermined member length and the experimental joint 62 is joined to both ends thereof, the frame factor of the unit member 60 from the member length and the joint specifications. Is calculated. Then, the Ds value of the layer structure portion S of the dome-like structure 10 composed of the unit members 60 having this frame coefficient is calculated. Then, a structural characteristic coefficient curve can be obtained by plotting the frame coefficient calculated for each member length of the unit member 60 and the corresponding Ds value on a two-dimensional plane.

This structural characteristic coefficient curve is obtained by calculating the frame coefficient of the unit member 60 used in the actual construction from the joint specifications based on the experimental results of the experimental joint 62 in actual design. The Ds value can be easily obtained without newly calculating the Ds value of each layer structure S. Thereby, it is possible to easily obtain the Ds value of each layer structure portion S of various types of dome-like structures 10 having different sizes and the like, and high-precision Ds for each dome-like structure 10 having different scales. The value can be determined and the seismic design can be performed efficiently.
(Claim 2)
According to a second aspect of the present invention, the structural characteristic coefficient curve is obtained by changing the frame coefficient of the plurality of types of the unit members 60 and the long-term axial force applied to the unit members 60. The maximum value is obtained based on the points plotted on the two-dimensional plane for each of the layer structure portions S.

The structural characteristic coefficient curve is drawn on the basis of two-dimensionally plotted the frame coefficients of several types of unit members 60 and the maximum value of the Ds value when the long-term axial force applied to each unit member 60 is varied. It is. Thereby, even if the long-term axial force of the unit member 60 is different, a safer numerical value in the seismic design can be adopted as the Ds value. In the seismic design of the dome-shaped structure 10 having different loads and different long-term axial forces due to different scales, the dome-shaped structure 10 standing on the safer side can be designed.
(Claim 3)
In the invention according to claim 3, the structural characteristic coefficient curve determines the maximum Ds value for each frame coefficient from the respective structural characteristic coefficient curves obtained for each of the plurality of types of the experimental joints 62. Each frame coefficient and its maximum Ds value are obtained based on points plotted on a two-dimensional plane.

In the present invention, even when the type of the experimental joint 62 is different, a safer numerical value in the seismic design can be adopted as the Ds value. Thereby, it is possible to perform the earthquake-proof design of the dome-like structure 10 standing on the safer side.
(Claim 4)
The invention according to a fourth aspect is provided for each layer structure portion S of the dome-like structure 10 using the structural characteristic coefficient curve derived by the method for deriving the structural characteristic coefficient curve according to the first, second, or third aspect. A method of determining a structural characteristic coefficient for determining a structural characteristic coefficient, comprising: a member length of a frame member 50 to be actually used; and the joint portion specifications of the joint piece 77 included in the connector 71; A step of calculating a frame coefficient based thereon, and a step of applying the frame coefficient calculated in the above step to the structural characteristic coefficient curve and determining a Ds value of each corresponding layer structure portion S.

Here, the “dome-shaped structure 10”, “frame member 50”, “connector 71”, “layer structure portion S”, and “joint piece 77” are the same as those described in the same term in claim 1. is there.
The present invention merely calculates the frame coefficient based on the frame member 50 from the member length of the frame member 50 actually used and the joint portion specifications of the joint piece 77 included in the connector 71 by using the structural characteristic coefficient curve. The Ds value of each layer structure portion S of the dome-like structure 10 can be easily obtained without newly calculating. Thereby, it is possible to easily obtain the Ds value of each layer structure portion S of various types of dome-like structures 10 having different sizes and the like, and high-precision Ds for each dome-like structure 10 having different scales. The value can be determined and the seismic design can be performed efficiently.

Since this invention is comprised as mentioned above, there exists an effect as described below.
According to the first aspect of the present invention, it is possible to provide a method for deriving a structural characteristic coefficient curve used for obtaining Ds values of various dome-shaped structures having different scales when performing seismic design employing Ds values. it can.
According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, it is used to obtain the Ds value of the dome-like structure standing on the safer side in the seismic design of the dome-like structure. A method for deriving a structural characteristic coefficient curve can be provided.
According to the invention described in claim 3, in addition to the effects of the invention described in claim 1 or 2, in the seismic design of the dome-shaped structure, the structural characteristic coefficient of the dome-shaped structure standing on the safer side. A method for deriving a curve can be provided.
According to the fourth aspect of the present invention, it is possible to easily determine the Ds value of the dome-shaped structure of various scales when determining the seismic design using the Ds value. A method can be provided.

1 is an external perspective view showing a triangular structure of a dome-like structure according to an embodiment of the present invention. It is embodiment of this invention, Comprising: It is an external appearance side view which shows the triangular structure of a dome-shaped structure. It is an embodiment of the present invention, and is an external plan view showing a triangular structure of a dome-shaped structure. It is an embodiment of the present invention, and is an external view showing a frame member and a connector of a triangular structure viewed from the indoor side. BRIEF DESCRIPTION OF THE DRAWINGS It is embodiment of this invention, (A) is a conceptual diagram of one unit member in a dome-shaped structure, (B) is a conceptual diagram which shows each part of the unit member, (C) performs a tension experiment. It is a conceptual diagram of the junction part for experiment. It is an embodiment of the present invention, and is a conceptual diagram showing a concept of reference rigidity of a unit member. It is embodiment of this invention, Comprising: It is a flowchart which shows derivation | leading-out of the structural characteristic coefficient curve of each hierarchy of a dome-shaped structure. It is an embodiment of the present invention, and is a flowchart showing determination of Ds values of each layer of a dome-shaped structure after derivation of a structural characteristic coefficient curve. It is embodiment of this invention, Comprising: It is a table which shows an example of the numerical value which calculated the frame coefficient of the unit member. FIG. 5 is a conceptual diagram illustrating an embodiment of the present invention, in which a plasticity factor and a Ds value of a predetermined layer are calculated based on a relationship between interlayer displacement and shearing force. It is embodiment of this invention, Comprising: It is a graph which shows the change of Ds value of the predetermined | prescribed hierarchy by the fluctuation | variation of long-term axial force. In the embodiment of the present invention, (A) is a graph showing the relationship between the long-term axial force and the Ds value of each layer, and (B) is a conceptual diagram for explaining the graph showing the relationship. It is embodiment of this invention, Comprising: It is a graph which shows the relationship between the frame coefficient of the unit member in different long-term axial forces, and Ds value of a predetermined | prescribed hierarchy. FIG. 5 is a graph showing a relationship between a frame coefficient of a unit member and a Ds value of each layer with a structural characteristic coefficient curve, which is an embodiment of the present invention.

Hereinafter, a method for deriving a structural characteristic coefficient curve used for obtaining the Ds value of the dome-shaped structure 10 and a structural characteristic coefficient determining method for determining the Ds value of the dome-shaped structure 10 using this structural characteristic coefficient curve. Before describing, an outline of a dome-like structure to be applied will be described.
As shown in FIGS. 1, 2, and 3, the dome-like structure 10 according to the embodiment is provided with a dome wall 520 that covers the periphery in a dome shape (hemisphere).

  The dome wall 520 includes a plurality of triangular structures 40 formed by connecting the ends of three frame members 50 provided at positions corresponding to the sides of the triangle, without any gaps. Are formed in a dome shape.

The dome-like structure 10 is formed by a hierarchical structure in which five layers of the layer structure portion S formed in an annular shape by connecting the triangular structures 40 without gaps are stacked.
The layer structure portion S is a structure portion located at the uppermost portion, and is a first structure portion 11 as a ceiling portion having a shape in which five triangular structures 40 inscribed in the same sphere are combined in a pentagonal shape without gaps. have.

  The layer structure portion S is connected to the first structure portion 11 below the first structure portion 11 without gaps, and a plurality of triangular structures 40 inscribed in the same sphere are annularly combined without gaps. The second structure portion 12 having a different shape is provided. The layer structure portion S is connected to the second structure portion 12 below the second structure portion 12 without gaps, and a plurality of triangular structures 40 inscribed in the same sphere are annularly combined without gaps. The third structure portion 13 having a different shape is provided. The layer structure portion S is connected to the lower side of the third structure portion 13 without any gap with the third structure portion 13, and a plurality of triangular structures 40 inscribed in the same sphere are annularly combined without gaps. The fourth structure portion 14 having a different shape is provided. The layer structure portion S is connected to the lower side of the fourth structure portion 14 with no gap between the fourth structure portion 14 and a fifth shape having a shape in which a plurality of triangular structures 40 are combined in a substantially annular shape. It has a structure part 15. The fifth structural portion 15 is fixed on a foundation 30 made of concrete (see FIG. 2).

  In the present embodiment, in the second structure portion 12 to the fifth structure portion 15, the triangular structure 40 in the same hierarchy has a forward triangle structure in which two vertices are arranged on the lower side and one vertex is arranged on the upper side. There are two types of triangular structures 40: a body 42 and an inverted triangular structure 41 having one vertex on the lower side and two vertices on the upper side. The forward triangular structure 42 is in contact with the upper layer only at the apex of the triangle, and the inverted triangular structure 41 is in contact with the upper layer with the sides of the triangle. That is, the inverted triangular structure 41 is a so-called “inverted triangle”. And as the layer structure part S of the same hierarchy from the 2nd structure part 12 to the 5th structure part 15, the alternating layer structure part by which the forward triangle structure body 42 and the inverted triangle structure body 41 were alternately arrange | positioned on the circumference 20 is formed (see FIG. 2). The first structure portion 11 is formed by five forward triangular structures 42.

In the present embodiment, the first structure portion 11 to the fourth structure portion 14 are composed of a large number of triangular structures 40 that are inscribed in the same sphere having a radius R. The fifth structure portion 15 is composed of a large number of triangular structures 40 that are inscribed in the same cylinder. As shown in FIGS. 1 and 2, the forward triangular structure 42 of the fifth structure portion 15 is not provided with the frame member 50 corresponding to the position of the bottom side. There, the upper surface of the foundation 30 indicated by the one-dot chain line in FIGS. 1 and 2 is arranged.
The dome-like structure 10 includes connectors 71 as fixing means 70 that connect the ends of the frame member 50 and are provided at positions where the vertices of the triangles of the triangular structure 40 gather. The connector 71 is provided with a plurality of plate-like joining pieces 77 to which end portions of the frame member 50 are joined in a radial manner.

A wooden frame member 50 provided at a position corresponding to each side of each triangular structure 40 and a metal connector 71 as a fixing means 70 provided at a position corresponding to each vertex of each triangular structure 40. Thus, the skeleton of the dome-shaped truss structure shown in FIG. 1 is constructed. The dome-shaped truss skeleton serves as a structural housing of the dome-shaped structure 10.
The connector 71 provided at the lower end of the fifth structure portion 15 is referred to as a base connector 72. The base connector 72 is for connecting the end portions of the frame member 50 gathering at the apex of the lower end of the fifth structure portion 15. The base connector 72 has two joining pieces 77 and functions as a member for connecting the ends of the two frame members 50, and also as a member for joining the truss skeleton to the foundation 30. Function.

The connector 71 provided on the boundary line between the fourth structure portion 14 and the fifth structure portion 15 is referred to as a beam connector 73. The beam connector 73 has six joining pieces 77 and connects the ends of the six frame members 50 gathered at the apex on the boundary line between the fourth structure portion 14 and the fifth structure portion 15. It is.
Further, between the fourth structure portion 14 and the fifth structure portion 15 are provided beams (not shown) for providing a ceiling on the first floor and a floor on the second floor. That is, in the dome-shaped structure 10 according to the present embodiment, the first structure layer is provided by the fifth structure portion 15 and the second structure layer is formed by the fourth structure portion 14 to the first structure portion 11. A hierarchy is provided.

The floor on the second floor may not be provided on the entire surface but may be provided on only a part of the floor and the other floors may be provided with no floor. Further, the hierarchical structure is not limited to the first floor and the second floor, and may be only the first floor.
A connector 71 other than the base connector 72 and the beam connector 73, which has five joining pieces 77 and where the ends of the five frame members 50 gather (positions where the apexes of the five triangular structures 40 gather) The connector 71 provided in FIG. The five connectors 74 are for connecting the ends of the five frame members 50 gathered at the positions.
A connector 71 other than the base connector 72 and the beam connector 73, which has six joining pieces 77 and where the ends of the six frame members 50 gather (positions where the apexes of the six triangular structures 40 gather) The connector 71 provided in FIG. The six connectors 75 are for connecting the ends of the six frame members 50 gathered at that position. Further, the five connectors 74 are arranged at the central part of the pentagon at the top, and the ends of the five frame members 50 forming the five triangular structures 40 are gathered.

As shown in FIG. 4, in one triangular structure 40, frame members 50 are arranged at positions corresponding to the sides of the triangle. The ends of the frame member 50 are fixed to each other by a connector 71 (in FIG. 4, only the upper connector 71 of the central triangular structure 40 is shown, and the detailed view of the other connectors 71 is omitted. ing). A triangular structure 40 shown in FIG. 4 represents one of the triangular structures 40 of the third structure portion 13, and the connector 71 arranged at the position corresponding to the apex of the triangle has 6 A connector 75 is formed.
The six connector 75 has a hub 76, a reinforcing flat plate portion 78, and six joining pieces 77.
The hub 76 is cylindrical. The reinforcing flat plate portion 78 has a disk shape provided so as to close one opening of the hub 76. The joining pieces 77 are for joining the frame member 50, and are composed of six flat plates protruding outward from the outer peripheral surface of the hub 76.

The joining pieces 77 are provided in the same number (six) as the frame members 50 gathering at the apex of the triangle where the six connectors 75 are arranged. Six frame members 50 gather at the apex of the triangle where the six connectors 75 are arranged.
Each joining piece 77 has an end joined to both the outer peripheral surface of the hub 76 and the reinforcing flat plate 78. Thereby, sufficient strength to support the frame member 50 with the joining piece 77 is exhibited.

  The frame member 50 is disposed at a position corresponding to each side of the triangular structure 40. The frame member 50 has a rectangular cross section perpendicular to the longitudinal direction, and the entire shape is formed from a rectangular parallelepiped wood. The end of the frame member 50 is fixed to the joining piece 77 of the connector 71 with bolts and nuts (not shown). The three frame members 50 provided at positions corresponding to the sides of the triangle are connected by the connector 71, whereby the triangular structure 40 serving as a triangular truss skeleton is formed.

  In the present embodiment, the frame member 50 is fixed to a single joining piece 77 of the connector 71, but is not limited to a single frame member 50. Absent. For example, two long frame members 50 may be fixed to one joining piece 77. In such a case, the end portions of the two frame members 50 are sandwiched between the end portions of the two long frame members 50 so that the end portions of the two frame members 50 are on both sides of the one joint piece 77. To fix. Note that the fixing method is not limited to this.

When designing a house with the dome-like structure 10 having the above-described structure, it is necessary to perform an earthquake-resistant design specified in the Building Standard Law. As a seismic design in the event of a large earthquake, structural calculations that can confirm safety can be performed by calculating the required horizontal strength.
Here, the structural characteristic unit is a numerical value required for the seismic design, and as shown in the equation (1), the necessary holding horizontal proof stress is calculated based on the Ds value, thereby the dome-shaped structure. Can be seismic design.
Qun = Ds × Fes × Qud (1)
Here, Qun is a necessary horizontal resistance, Ds is a structural characteristic coefficient, Fes is a shape coefficient, and Qud is a horizontal force in the case of an elastic response generated in each floor by a seismic force.

As shown in FIG. 5A, one unit member 60 is provided as a concept for calculation when determining the Ds value of the dome-shaped structure 10. As shown in FIG. 5B, the unit member 60 is provided with one frame member 50 and an experimental joint 62 in which the joining pieces 77 of the connector 71 are fixed to both ends of the frame member 50. Yes. It should be noted that the tensile strength test of the experimental joint 62 corresponding to one end of the unit member 60 as shown in FIG. The experiment is to be performed. That is, an experiment on the tensile strength of an experimental joint 62 having a joint piece 77 on one end side of the unit member 60 and an experimental frame member 51 on one end side joined to the joint piece 77 is performed.
As shown in FIG. 6, in the unit member 60, the experimental joints 62 and the frame member 50 at both ends are arranged in series. Thereby, the reference stiffness K including the experimental joint 62 of the unit member 60 is determined based on the reference stiffness Ko of the wooden frame member 50 and the strength experimental result of the experimental joint 62. (2) using the reference stiffness Ki.
1 / K = 1 / Ki + 1 / Ko + 1 / Ki = 1 / Ko + 2 / Ki (2)
A method for deriving the structural characteristic coefficient curve of each layer of the dome-shaped structure 10 will be described with reference to FIG.
In the present embodiment, an experimental joint 62 in which a joint piece 77 independent of the connector 71 is joined to the end of the experimental frame member 51 having a predetermined material and cross-sectional shape is used as a tensile strength test piece. use.
Further, in the present embodiment, the concept of the unit member 60 that assumes that the experimental frame member 51 has a predetermined member length and the experimental joint portion 62 is joined to both ends thereof is used for the convenience of calculation. (See FIG. 5).
Further, in the present embodiment, the fifth structure unit 15 is set as the first floor layer, and the Ds value of the first floor layer is calculated using the first floor layer as one layer structure unit. Then, the fourth structure portion 14 to the first structure portion 11 are set as the second floor layer, and the four layer structure portions S of the second floor layer as a whole are regarded as one layer structure portion, and the Ds value of the second floor layer. Is calculated.

First, in step 110, the end of the experimental frame member 51 made of wood of Young's modulus Eo and having a cross section of thickness b, height D, and cross-sectional area A (b × D) is joined independently from the connector 71. The experimental joint 62 in which the pieces 77 are joined is manufactured. Then, the process proceeds to the next step 111.
In step 111, a strength experiment of the experimental joint 62 is performed, and based on the result of the strength experiment, the reference ultimate strength Pu, the reference rigidity Ki, and the plastic modulus μi of the experimental joint 62 are determined. . Here, the average of six test pieces is used for the reference ultimate strength Pu and the reference rigidity Ki. These values are all determined by the experimental results of the tensile strength of the experimental joint 62.

  Here, the strength experiment of the experimental joint 62 is an experimental experiment in which a joint piece 77 independent of the connector 71 is joined to the end of the experimental frame member 51 in the same manner as actual joining means (bolts, nuts, etc.). This is performed by a tensile experiment in which both ends of the joint 62 are pulled. Actually, the experimental frame member 51 on one end side of the experimental joint 62 and the joint piece 77 independent of the connector 71 on the other end side of the experimental joint 62 are pulled by a tensile tester to load and strain. A (displacement) curve is derived. Based on the result, the above-described joint specifications of the experimental joint 62 are determined. Then, the process proceeds to the next step 112.

In step 112, the yield displacement δvi of the experimental joint 62 and the ultimate displacement δui of the experimental joint 62 are determined from the plasticity ratio μi of the experimental joint 62. The yield displacement δvi of the experimental joint 62 is calculated by equation (3), and the ultimate displacement δui is calculated by equation (4).
δvi = Pu / Ki (3)
δui = μi × δvi (4)
Then, the process proceeds to the next step 113.

In step 113, the rigidity Ko of the frame member 50 is (5) based on the thickness b, height D, cross-sectional area A (b × D), length L, and Young's modulus Eo of the frame member 50. Determined by the formula.
Ko = Eo × A / L (5)
Then, the process proceeds to next Step 114.

In step 114, the yield displacement δvj of the unit member 60, the ultimate displacement δuj of the unit member 60, the plasticity factor μj of the unit member 60, and the frame coefficient dsj of the unit member 60 are calculated.
Since the reference stiffness K including the experimental joint 62 of the unit member 60 is expressed by the equation (2), the yield displacement δvj of the unit member 60 is expressed by the equation (6) according to Hooke's law.
δvj = Pu × 1 / K = Pu × (1 / Ko + 2 / Ki) (6)
The ultimate displacement δuj of the unit member 60 is calculated by equation (7), the plasticity ratio μj of the unit member 60 is calculated by equation (8), and the frame coefficient dsj of the unit member 60 is calculated by equation (9). In this embodiment, the load deformation relationship is a bilinear type.
δuj = Pu / Ko + 2 × δui (7)
μj = δuj / δvj (8)
dsj = 1 / √ (2 × μj−1) (9)
Then, the process proceeds to the next step 115.

In step 115, the frame coefficient ds of the unit member 60 obtained by statistically correcting the frame coefficient dsj of the unit member 60 determined as described above to a numerical value on the safer side, and the plasticity ratio μ of each layer are determined. Specifically, the average value m of dsj is determined, and the average value 1-m of 1-dsj is determined. Then, the standard deviation S is determined, the 5% lower limit value ((1-m) -2.336 × S) is determined, and the 5% lower limit of the unit member 60 is determined by the value of (1- (5% lower limit value)). The frame coefficient ds of the unit member based on the value is determined. The plasticity ratio μ of each unit member 60 is determined by substituting the value of ds into the equation (10) and rearranging it to determine the plasticity ratio μ of the unit member 60 based on the 5% lower limit value.
ds = 1 / √ (2 × μ−1) (10)

  In step 116, the Ds value of each layer of the dome-like structure 10 using each unit member 60 is determined by calculation for each predetermined long-term axial force (see FIG. 11). Here, the long-term axial force is set to vary within an assumed range. As a result, even if fluctuations in the weight of the building itself due to differences in the size (scale) of the dome-shaped structure 10 or fluctuations due to differences in the load of what is loaded on this building occurred, it stood on the safer side The Ds value can be acquired.

  Specifically, static elasto-plastic analysis is performed by inputting a predetermined numerical value for each predetermined long-term axial force into an analysis model using a computer. Then, based on the fact that a predetermined predetermined condition (collapse condition) has been reached, the interlayer displacement in each layer is calculated, the plasticity rate of each layer is determined, and the Ds value of each layer is calculated from this plasticity rate It is what you are doing. Then, the process proceeds to Step 117.

  In step 117, for each predetermined long-term axial force, on the two-dimensional plane on the xy coordinate axis, the frame coefficient of the plurality of types of unit members 60 is the x axis and the Ds value of each layer using each unit member 60 is the y axis. Is plotted as a point (x, y). Specifically, a frame coefficient calculated for each member length of each unit member 60 and a Ds value corresponding to the frame coefficient are plotted on a two-dimensional plane at a predetermined long-term axial force. Furthermore, the Ds value of each layer when the long-term axial force is varied is similarly plotted (see FIG. 13). Then, the process proceeds to next Step 118.

In step 118, an approximate curve of the point that becomes the maximum value of the Ds value of each layer for each frame coefficient of the unit member 60 is obtained. Specifically, an approximate curve of a point that is the maximum value of the Ds value of each layer of the y axis in each value of the x axis (the frame coefficient of the unit member 60) is drawn (see FIG. 14). The approximate curve is a structural characteristic coefficient curve of each layer of the dome-shaped structure 10. Then, the stage ends.
As shown in FIG. 8, the method for determining the Ds value of each layer of the dome-shaped structure 10 after the derivation of the structural characteristic coefficient curve is as follows.

  In step 210, the frame coefficient of the unit member 60 is determined based on the frame member 50 (see FIG. 5) actually used. Specifically, in the case where the experimental joint 62 is the same and only the dimensions such as the length L of the frame member 50 are different, from step 110 to step 115 based on the experimental results already obtained. The frame coefficient of the unit member 60 can be calculated (except for the strength experiment of the experimental joint 62). Then, the process proceeds to the next step 211.

  In step 211, the Ds value of each layer is determined using the structural characteristic coefficient curve (see FIG. 14) for determining the Ds value of each layer from the frame coefficient based on the frame member 50 actually used. Thereby, each step of the determination method ends.

  As a result, after the structural characteristic coefficient curve of each layer is once derived in step 118 of FIG. 7, the frame coefficient based on the frame member 50 that is actually used is calculated, and the structural characteristic coefficient curve is used. Thus, the Ds value of each layer is determined.

  As shown in FIG. 9, as an example, among a plurality of types of experimental joints 62, strength tests are actually performed on six specimens No. 1 having the same size and shape with respect to the specimen No. 1 of the experimental joint 62. It was broken. Based on this experimental result, the joint part specifications of the experimental joint part 62 of the test body number No1 are determined. The frame coefficient of the unit member 60 that finally stands on the safe side is determined by substituting into the above-described calculation formula from the specifications of the joint. According to the experimental result of FIG. 9, the frame coefficient of the unit member 60 is determined to be 0.584. Based on the experimental result of the test joint number 62 of the test body number No. 1, by changing the dimensional shape such as the length L of the frame member 50 in FIG. A coefficient is determined. In addition, although not particularly illustrated, actually, the strength experiment of the seven types of experimental joints 62 from the test body numbers No1 to No7 having different dimensional shapes is repeatedly performed a plurality of times.

  As shown in FIG. 10, the shearing force applied to a predetermined hierarchy (specifically, the first floor) and the interlayer displacement can be determined by computer analysis using an analysis model. This is because in the dome-like structure 10 having the unit member 60 of a predetermined length provided with both ends of the experimental joint 62 (specifically, test body number No. 3) having predetermined joint specifications. Each numerical value obtained is input into an analysis model using a computer, and incremental analysis (static elasto-plastic analysis) is performed under a predetermined long-term axial force. The yield displacement δv of this level indicates the displacement at the time when the experimental joint 62 of a certain unit member 60 reaches the yield strength. Further, the ultimate displacement δu of the layer indicates the displacement at the time when the plasticity ratio μ obtained from the 5% lower limit value of the experimental joint 62 obtained from the strength experiment is reached. Thereby, the Ds value of the said hierarchy of this Embodiment is evaluated by the safe side. As a result, as shown in FIG. 10, a point slightly exceeding the elastic region is the ultimate displacement δu, and the ultimate displacement δu and the yielding displacement δv at that point are used to determine the plastic modulus μ of each layer. Is determined by the equation (11), and the Ds value of the layer is determined by the equation (12) by the plasticity ratio μ.

μ = δu / δv (11)
Ds = 1 / √ (2 × μ−1) (12)
And although not specifically illustrated, in each of the plural types of experimental joints 62 of the test body numbers No1 to No7, the unit members 60 having different dimensional shapes such as the length L of the frame member 50 are shown in FIG. By performing such processing, the Ds value of each layer using each unit member 60 under a predetermined long-term axial force is determined.

  In FIG. 10, in the predetermined unit member 60, the yield displacement δv and the ultimate displacement δu are determined under a predetermined long-term axial force, and thereby the plastic modulus μ and the Ds value are determined. . In FIG. 11, the calculation as shown in FIG. 10 is performed by varying the long-term axial force in the predetermined unit member 60.

  As a result, the yield displacement δv decreases at a moderate decrease rate as the long-term axial force increases. The ultimate displacement δu is a large value when the long-term axial force is small, and the ultimate displacement δu decreases as the long-term axial force increases up to a predetermined long-term axial force. If it exceeds, the method of decreasing the ultimate displacement δu becomes gradual.

Due to the changes in the displacement δv at the time of yield and the displacement δu at the time of ultimate accompanying the fluctuation of the long-term axial force as described above, the Ds value (black circle in the figure) of this layer is long-term axial force while the numerical value of the long-term axial force is small. Increases as the value increases, reaches a predetermined long-term axial force, shows a maximum value, and then gradually decreases. FIG. 11 shows the results for the predetermined unit member 60, but the other types of unit members 60 have the same numerical analysis results with respect to the increase / decrease tendency although the absolute values of the numerical values are different. As a result of analyzing the relationship between the long-term axial force and the Ds value shown in FIG. 11 for other types of unit members 60 in the same manner, the general tendency is shown in FIG.
As shown in (a), (b), (c), and (d) of FIG. 12A, for the unit member 60 used for the dome-shaped structure 10, the relationship between the long-term axial force and the Ds value of each layer is Generally, the following tendencies are shown.

That is, as shown in FIGS. 12A and 12B, the Ds value of each layer of the dome-shaped structure 10 increases as the long-term axial force increases in the range where the numerical value of the long-term axial force is small. Increase (high value).
And as shown to (c) of FIG. 12 (A), the value of Ds value of each hierarchy of the dome-shaped structure 10 shows the maximum value in a predetermined long-term axial force.
Thereafter, as shown in FIG. 12 (A) (d), the Ds value of each layer of the dome-shaped structure 10 gradually increases as the long-term axial force increases above a predetermined long-term axial force. Shows a decreasing trend.

  In (a) to (c) of FIG. 12 (A) where the long-term axial force is a relatively small value, both the compression-side and tensile-side unit members 60 shown in FIG. On the other hand, in (c) to (d) of FIG. 12A in which the long-term axial force has increased, the unit member 60 on the tension side shown in FIG. This is because the compression-side unit member 60 yields the shaft.

In the present embodiment, by changing the long-term axial force within a predetermined application range, it is possible to cope with a change in the building scale of the dome-shaped structure 10 and a change due to snow load. Further, by performing a strength experiment using a plurality of types of experimental joints 62 assumed to be used within the applicable range, it is possible to cope with different types of unit members 60.
Next, from a different perspective, it is assumed that the length of the frame member 50 is changed due to the height (floor height) of each floor of the dome-shaped structure 10 and the scale of the dome-shaped structure 10. . For this reason, the length L of the frame member 50 of the unit member 60 was changed, and the influence on the Ds value of each layer when the frame coefficient of the unit member 60 varied was examined.

  FIG. 13 shows the relationship between the frame coefficient of the unit member 60 and the Ds value of a predetermined hierarchy (specifically, the first floor) in a plurality of long-term axial forces. This is because the frame coefficient of the unit member 60 is changed by changing the length L (see FIG. 9) of the frame member 50 based on the experimental result of the experimental joint 62 already performed. . A frame coefficient calculated for each length L of each unit member 60 at a predetermined long-term axial force and a Ds value of a predetermined hierarchy (first floor) corresponding to the frame coefficient are calculated by an analysis model to be two-dimensional It is plotted on a plane. Then, the same work is performed by changing the long-term axial force, and the same plot is made for each of the eight different long-term axial forces. Note that FIG. 13 is obtained from one type of experimental joint 62 and is not particularly illustrated, but based on the strength experiment results of other types of experimental joints 62, the unit member A similar graph is created for each of the 60 types. Note that when only one type of experimental joint 62 is used, such work is not necessary, and only this graph is used.

As a result of creating the graph of FIG. 13 and other types of unit members 60 and examining each long-term axial force, for each value of the frame coefficient of the unit member 60, A predetermined long-term axial force that maximizes the Ds value was revealed.
Then, the frame coefficient of the plurality of types of unit members 60 and the maximum value of the Ds value of each layer when the long-term axial force applied to each unit member 60 is varied are plotted as points on the two-dimensional plane for each layer. To do.

Furthermore, the maximum Ds value is determined for each frame coefficient from the structural characteristic coefficient curve obtained for each of the plurality of types of experimental joints 62, and each frame coefficient and the maximum Ds value are newly determined in a two-dimensional plane. Plot on top.
Then, by superimposing the plotted points for each layer and connecting the points having the maximum Ds value of each layer with respect to the frame coefficient of the unit member 60 by a curve, the structural characteristic coefficient curve shown in FIG. 14 is obtained.
As shown in FIG. 14, the Ds value of each layer of the structural characteristic coefficient curve is a numerical value that is higher on the first floor than on the second floor.

  When the earthquake-resistant design of the dome-shaped structure 10 is performed, the experimental joint 62 based on the joint piece 77 included in the frame member 50 and the connector 71 that are actually used is the same as the experimental joint 62 that has already been subjected to the strength experiment. However, when the scale (size, diameter) of the dome-like structure 10 is different and the dimensional shape such as the length of the frame member 50 having the experimental joint 62 at both ends is different, as shown in FIG. In addition, by performing the same calculation from the joint specifications of the experimental joint 62 already obtained, the frame coefficient of the unit member 60 can be calculated only on the desk without performing a new strength experiment. Can be easily obtained. After the frame coefficient of the unit member 60 is determined, the Ds value of each layer can be easily obtained from the frame coefficient of the unit member 60 using the structural characteristic coefficient curve of FIG. it can.

  Further, when the earthquake-resistant design of the dome-shaped structure 10 is performed, the experimental joint 62 based on the joint piece 77 included in the frame member 50 and the connector 71 that are actually used is the experimental joint 62 that has already been subjected to the strength experiment. If they are not the same, by carrying out a strength experiment of this experimental joint 62, the joint specifications (reference ultimate proof strength Pu, standard stiffness Ki, plastic modulus μi) of this experimental joint 62 are determined. Can do. And if the said joint part specification of this experimental junction 62 is determined, the frame coefficient of the unit member 60 can be easily obtained by performing the calculation as described in FIG. Then, after the frame coefficient of the unit member 60 is determined, the Ds value of each layer can be easily obtained from the frame coefficient of the unit member 60 using the structural characteristic coefficient curve of FIG.

  In the present embodiment, a strength experiment of the experimental joint 62 is performed, and joint specifications such as a plastic modulus of the experimental joint 62 are obtained based on the experimental result. For the unit member 60 that is assumed that the experimental frame member 51 has a predetermined member length and the experimental joint 62 is joined to both ends thereof, the frame factor of the unit member 60 from the member length and the joint specifications. Is calculated. Then, the Ds value of each layer of the dome-like structure 10 composed of the unit members 60 having this frame coefficient is calculated. Then, a structural characteristic coefficient curve can be obtained by plotting the frame coefficient calculated for each member length of the unit member 60 and the corresponding Ds value on a two-dimensional plane.

  The structural characteristic coefficient curve according to the present embodiment plots the frame coefficients of several types of unit members 60 and the maximum value of the Ds value when the long-term axial force applied to each unit member 60 is varied in a two-dimensional manner. It is drawn based on the points. Thereby, even if the long-term axial force of the unit member 60 is different, a safer numerical value in the seismic design can be adopted as the Ds value. In the seismic design of the dome-shaped structure 10 having different loads and different long-term axial forces due to different scales, the dome-shaped structure 10 standing on the safer side can be designed.

In the present embodiment, even when the type of the experimental joint 62 is different, a safer numerical value in the seismic design can be adopted as the Ds value. Thereby, it is possible to perform the earthquake-proof design of the dome-like structure 10 standing on the safer side.
In the structural characteristic coefficient curve according to the present embodiment, the frame coefficients of the plurality of types of unit members 60 and the maximum Ds value of each layer when the dimensions of the unit members 60 are varied are two-dimensionally displayed. It is drawn based on the plotted points. Thereby, even when the dimensions of the unit member 60 are different, the values on the safer side in the seismic design can be adopted as the structural characteristic coefficient of each layer. In the seismic design of the dome-like structure 10 having different scales due to the different lengths of the unit members 60, the seismic design of the dome-like structure 10 standing on the safer side can be performed.

  In the present embodiment, by using the structural characteristic coefficient curve, the frame coefficient based on the frame member 50 is calculated from the member length of the frame member 50 actually used and the joint portion specifications of the joint piece 77 included in the connector 71. Thus, the Ds value of each layer of the dome-shaped structure 10 can be easily obtained without newly calculating. Thereby, it is possible to easily obtain the Ds values of the respective layers of the various types of dome-shaped structures 10 having various sizes and the like, and to obtain a highly accurate Ds value for each dome-shaped structure 10 having different scales. The seismic design can be performed efficiently.

10 Dome-shaped structure S-layer structure
11 1st structure part 12 2nd structure part
13 Third structure 14 Fourth structure
15 Fifth structure part 20 Alternating layer structure part
30 foundation 40 triangular structure
41 inverted triangle structure 42 forward triangle structure
50 Frame member 51 Experimental frame member
60 Unit member 62 Experimental joint
70 Fixing means 71 Connector
72 Base connector 73 Beam connector
74 5 connectors 75 6 connectors
76 Hub 77 Joint
78 Reinforcing plate 520 Dome wall

Claims (4)

A seismic design of a dome-like structure having a multi-layer structure in which a plurality of triangular structures inscribed in the same sphere are connected to form an annular layer structure by connecting the triangular structures without gaps. A method for deriving a structural characteristic coefficient curve used to obtain a structural characteristic coefficient necessary for the design stipulated in the Building Standard Law for each of the layer structure portions when performing,
The triangular structure is
Frame members respectively provided at positions corresponding to the sides of the triangle;
A connector provided to connect the frame members to each other and at a position where the vertices of each triangle gather;
The connector is provided with a joining piece to which the end of the frame member is joined,
Forming an experimental joint in which the joint piece independent of the connector is joined to an end of the experimental frame member having a predetermined material and cross-sectional shape;
Conducting a strength experiment on the experimental joint to obtain ultimate yield strength, rigidity and plasticity ratio (hereinafter referred to as “joint specifications”);
Regarding the unit member assumed that the experimental frame member has a predetermined member length and the experimental joint is joined to both ends thereof, the structural characteristics of the unit member from the member length and the joint specifications Calculating a coefficient (hereinafter referred to as “frame coefficient”);
Calculating a structural characteristic coefficient (hereinafter referred to as a “Ds value”) of each layer structure portion of the dome-shaped structure assumed to be composed of the unit members having the respective frame coefficients;
Plotting the frame coefficient calculated for each member length of each unit member and the Ds value corresponding to the frame coefficient in a two-dimensional plane;
Based on the plotted points, obtaining a structural characteristic coefficient curve of each layer structure,
A method for deriving a structural characteristic coefficient curve.   The structural characteristic coefficient curve includes, for each layer structure part, the frame coefficient relating to a plurality of types of unit members and the maximum Ds value of each layer structure part when the long-term axial force applied to each unit member is varied. 2. The method of deriving a structural characteristic coefficient curve according to claim 1, wherein the structural characteristic coefficient curve is obtained based on points plotted on a two-dimensional plane.   The structural characteristic coefficient curve determines the maximum Ds value for each frame coefficient from the respective structural characteristic coefficient curves obtained for each of the plurality of types of the experimental joints, and again determines each frame coefficient and its maximum Ds. 3. The method for deriving a structural characteristic coefficient curve according to claim 1, wherein the value is obtained based on each point plotted on a two-dimensional plane. A structural characteristic for determining a structural characteristic coefficient for each layer structure portion of the dome-like structure using the structural characteristic coefficient curve derived by the structural characteristic coefficient curve deriving method according to claim 1, 2 or 3. A coefficient determination method,
Calculating a frame coefficient based on the frame member from the length of the frame member to be actually used and the joint portion specifications of the joint piece included in the connector;
Applying the frame coefficient calculated in the above step to the structural characteristic coefficient curve to determine a Ds value of each corresponding layer structure;
A structural characteristic coefficient determination method characterized by comprising:

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