JP2006144482A - Frame structure of structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the frame structure of a structure capable of increasing the degree of freedom of a design on a lower frame by reducing a thrust working to the lower frame supporting an arch roof. <P>SOLUTION: The structure is composed of the arch roof 1 in which the span direction X is formed in a pent roof-shape-flowing arch shape. The arch roof 1 is formed in a curved-surface truss 2. The curved surface truss 2 is composed of arched main materials 5 juxtaposed in the girder-line direction while being extended in the span direction X, tie rods 6 built among the main materials 5 and 5 while crossed at right angles with the main materials 5 and diagonal members 7 arranged on the diagonals of grids formed of the main materials 5 and the tie rods 6. In a gable surface 4 extended in the span direction X of the structure, braces 8 made of steel pipes supporting the curved-surface trusses 2 are assembled in an elevation truss shape, and the lower end sections of each brace 8 are supported by SRC columns 10 made of steel framed reinforced concrete. Then, the lower frames 3 extended in the girder-line direction Y of the structure are constituted of steel-pipe columns 9 having a circular cross section juxtaposed in the girder-line direction Y. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a frame structure of a structure, and more particularly to a frame structure of a structure having an arch roof.

In the structure having the arch roof 50, a large thrust force S (boundary of the arch roof 50) is applied to the lower frame 51 that supports the arch roof 50 due to the vertical load V composed of the weight of the arch roof 50 and an additional load acting on the arch roof 50. Force) (see FIG. 6). For this reason, a strong lower frame is constructed to handle the thrust force.
On the other hand, in the dome structure, a method has been proposed in which both ends of the arch forming the opening are connected to the beam below the arch by a suspension cable to form a mechanically closed field, and the thrust force generated in the opening is processed. (See Patent Document 1).
Japanese Patent Laid-Open No. 10-211983 (2nd page, Fig. 1)

However, if the lower frame that receives thrust force has to be made into a structural form where it is difficult to ensure out-of-plane rigidity, such as a cantilever column, due to architectural plans and other constraints, a strong lower frame cannot be constructed. It is difficult to handle the thrust force on the frame.
Moreover, the span of the arch roof is almost always a long span in which a beam cannot be installed between the columns, and it is difficult to adopt the technique as in Patent Document 1.

  The present invention has been made in view of the above-described problems, and is a structural frame that can reduce the thrust force acting on the lower frame that supports the arch roof and thereby increase the degree of freedom in designing the lower frame. The purpose is to provide a structure.

To achieve the above object, a frame structure of a structure according to the present invention is a frame structure of a structure having an arch roof whose span direction is arched, and the arch roof extends in the span direction. Arch-shaped main members arranged side by side in the row direction, a connecting member constructed between the main members, and a diagonal member arranged on a diagonal line of a grid formed by the main member and the connecting member It is a curved truss.
In the case of a structure having an arch roof having an arch shape in the span direction, a thrust force is generated in the arch roof to expand the arch roof in the span direction. This thrust force acts as a large out-of-plane force on the lower frame that supports the arch roof at both ends of the span.
In the present invention, the direction of the force flow is changed in the roof surface by arranging the diagonal material on the arch roof formed in a grid shape with the main material and the connecting material. In other words, the thrust force acting in the span direction is transmitted to the end face of the structure via the diagonal member of the curved truss, and the thrust force acting on the lower frame at both ends of the span is greatly reduced. Yes. As a result, there is no need to strengthen the lower frame at both ends of the span, and the degree of freedom in design increases.

Further, in the frame structure of the structure according to the present invention, the end face extending in the span direction of the structure includes braces that support the curved truss on the pillars arranged in parallel. Also good.
In the present invention, the strength and rigidity of the wife surface are increased by assembling the braces on the columns arranged side by side, and the thrust force transmitted to the wife surface through the diagonal is processed. .

Moreover, in the frame structure of the structure which concerns on this invention, the edge part may be rigidly joined to the said main material in the said joining material arrange | positioned in the span direction center part of the said curved truss.
In the present invention, the buckling strength of the curved truss can be increased by rigidly joining the end of the connecting member disposed in the center portion in the span direction of the curved truss with the main material.

  According to the present invention, the arch roof is composed of an arch-shaped main material, a connecting material constructed between the main materials, and a diagonal material arranged on a diagonal line of a grid formed by the main material and the connecting material. By using the curved truss, the thrust force is concentrated on the end face of the structure, and the thrust force acting on the lower frame at both ends of the span is greatly reduced. As a result, it is not necessary to strengthen the lower frame at both ends of the span, and the degree of freedom in design can be increased.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a frame structure of a structure according to the present invention will be described based on the drawings.
FIG. 1 is a perspective view showing an example of a frame structure of a structure according to the present invention.
As shown in FIG. 1, the structure which concerns on this embodiment is a structure which consists of the arch roof 1 in which the span direction X became the arch shape of the single flow, and is constructed | assembled on the mat slab 12 of a reinforced concrete structure.
The span rise ratio indicating the ratio between the rise of the arch roof 1 and the arch span is about 0.05, and is generally called a low rise arch roof. The rise means the height from the line connecting the arch ends to the arch crown.

The arch roof 1 has a main material 5 formed in an arch shape that extends in the span direction X and is juxtaposed in the row direction Y, and a bridge that is laid between the main materials 5 and 5 orthogonal to the main material 5. This is a curved truss 2 composed of a material 6 and a diagonal material 7 arranged on a diagonal line of a grid formed by the main material 5 and the connecting material 6. However, the diagonal member 7 is not disposed in the central portion of the curved truss 2, and each corner portion of the curved truss 2 is obliquely inclined so that a rhombus is formed in the central portion of the curved truss 2 in plan view. The material 7 is arranged side by side. As will be described later, by arranging the diagonal member 7 in this manner, a tensile force always acts on the diagonal member 7 with respect to the vertical load, and consideration for buckling becomes unnecessary.
Steel members are used for the members of the curved truss 2, H-shaped steel is used for the main material 5 and the connecting material 6, and flat steel is used for the diagonal material 7.

On the end face 4 extending in the span direction X of the structure, a steel pipe brace 8 supporting the curved truss 2 is assembled in a truss shape in elevation, and the lower end of each brace 8 is an SRC column 10 made of steel reinforced concrete. Is a structure to support.
A SRC beam 11 made of steel reinforced concrete is laid between the SRC columns 10 and 10, and a RC wall 15 made of reinforced concrete is formed in the construction surface surrounded by the SRC columns 10 and 10 and the SRC beam 11.

  On the other hand, the lower frame 3 (the lower frame at both ends of the span) extending in the crossing direction Y of the structure is composed of steel pipe columns 9 having a circular cross section arranged side by side in the crossing direction Y, and has a large out-of-plane rigidity. The structure is difficult to secure.

  In addition, on one wife face 4 side, a projecting roof 1a having a triangular shape in a plan view is formed in which the upper side of the river is larger than the lower side of the river and is projected horizontally.

2A and 2B show the flow of force in the curved truss 2, wherein FIG. 2A is a plan view of the curved truss 2, and FIG. 2B is an axial force diagram of the portion A when a vertical load is applied. In the axial force diagram, the solid line represents the tensile force, the broken line represents the compressive force, and the width of the band is proportional to the magnitude of the axial force.
As shown in FIG. 2, compressive force acts on the main member 5 and the connecting member 6 constituting the curved truss 2 except for the end face main member 5a and the outer connecting member 6a constituting the outer peripheral portion, and the diagonal member 7 Tensile force acts on the end face main material 5a and the outer peripheral connecting material 6a.
The thrust force for expanding the curved truss 2 in the span direction X is changed in the direction of the force by the diagonal member 7 and acts as a tensile force on the end face main material 5a and the outer peripheral connecting material 6a. As a result, the thrust force acting in the out-of-plane direction acting on the lower frame 3 extending in the beam running direction Y is small enough to be processed by the steel pipe column 9.
On the other hand, the tensile force acting on the end face main material 5 a is processed as an in-plane force on the end face 4 that is rigidly constituted by the brace 8 and the SRC column 10.

FIGS. 3A and 3B show the water-side support portion of the curved truss 2, wherein FIG. 3A is a vertical sectional view of the structure, and FIG. 3B is a perspective view of the B portion.
The curved truss 2 is supported by the steel pipe column 9 via a pin bearing 13 having a rotation axis in the direction of crossing Y on the water side, so that no bending moment is generated at the end of the curved truss 2.
Further, a sliding plate 14 made of a stainless steel plate is interposed between the pin support 13 and the steel pipe column 9 and serves as a roller support when the curved truss 2 is constructed. Thereby, the stress at the time of construction does not remain on the members constituting the curved truss 2, and each member can fully process the vertical load. After completion, the sliding plate 14 is fixed to the pin support 13 and the steel pipe column 9, and the horizontal movement of the sliding plate 14 is restricted.

Next, the buckling strength of the curved truss 2 due to the difference in end joining conditions of the connecting material 6 will be described. As shown in FIG. 2, since a compressive force acts on the main member 5 and the connecting member 6 constituting the curved truss 2 at the time of vertical load, it is necessary to examine the buckling strength of the curved truss 2.
FIG. 4 shows an end joining condition of the connecting member 6 constituting the curved truss 2, and FIG. 4A shows a case where the connecting member 6 ′ in the central portion 1 row is rigidly connected to the main member 5. b) When the connecting members 6 ′ and 6 ′ in the central two rows are rigidly connected to the main material 5, (c), the connecting materials 6 ′, 6 ′ and 6 ′ in the three central rows are connected to the main material 5. This is a case of rigid connection.
On the other hand, FIG. 5 is a graph showing the relationship between the vertical load and the amount of deflection at the center point of the curved truss 2, and CASE 0 is a case where both ends of the connecting material 6 are all pin-joined with the main material 5, and CASE 1 is shown in FIG. ), CASE2 corresponds to the case of FIG. 4B, and CASE3 corresponds to the case of FIG. 4C. The fixed load is the sum of the weight of the curved truss 2 and the additional load acting on the curved truss 2, and the vertical axis is obtained by standardizing the vertical load with the fixed load, and the maximum vertical load is the buckling. Corresponds to load.
From FIG. 5, when both ends of the connecting material 6 are all pin-joined with the main material 5, the buckling load and the amount of deflection are the smallest, and the connecting materials 6 ′, 6 ′, 6 ′ in the central three rows are connected to the main material 5. It can be seen that the buckling load and the amount of deflection are the largest when rigid bonding is used. In addition, when the connecting members 6 ′ and 6 ′ in the central two rows are rigidly connected to the main material 5 and the connecting materials 6 ′, 6 ′ and 6 ′ in the three central rows are rigidly connected to the main material 5 It can be seen that the buckling load and the amount of deflection do not change so much.
Therefore, the buckling strength of the curved truss 2 can be effectively improved if the connecting members 6 ′ and 6 ′ in the central portion of the curved truss 2 are rigidly joined to the main material 5.

In the frame structure of the structure according to the present embodiment, the arch roof 1 is composed of an arch-shaped main material 5, a connecting material 6 laid between the main materials 5 and 5 orthogonal to the main material 5, and the main material 5. By forming the curved truss 2 composed of the diagonal member 7 arranged on the diagonal line of the grid formed by the connecting material 6, the thrust force is concentrated on the end surface 4 of the structure, and the lower portion extending in the column direction Y The thrust force acting on the frame 3 is greatly reduced. Along with this, the end face 4 has a structure in which braces 8 are assembled in a truss shape on the SRC pillars 10 arranged side by side, thereby increasing the strength and rigidity of the end face 4 so that the end face is interposed via the diagonal member 7. The thrust force transmitted to 4 is processed.
As a result, there is no need to strengthen the lower frame 3 extending in the column direction Y, the number of frames can be reduced, and the construction cost and construction period can be reduced. In addition, since it is not necessary to strengthen the lower frame 3 extending in the column direction Y, the degree of freedom in design can be increased.

  As mentioned above, although embodiment of the frame structure of the structure based on this invention was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it can change suitably. For example, in the above-described embodiment, a single-flow arch roof is used, but a double-flow arch roof having the highest span center may be used. In the above embodiment, the end face is composed of columns and truss-like braces arranged side by side, but the entire end face is composed of a reinforced concrete wall to process the thrust force transmitted to the end face. May be. In short, it is only necessary to obtain the desired function in the present invention.

It is a perspective view which shows an example of the frame structure of the structure based on this invention. The flow of force in the curved truss is shown, (a) is a plan view of the curved truss, (b) is an axial force diagram of the A part at the time of vertical load action. The waterside support part of a curved truss is shown, (a) is a sectional elevation view of the structure according to the present invention, and (b) is a perspective view of part B. The end joining conditions of the connecting material constituting the curved truss are shown, and (a) shows a case where the connecting material in the center part is connected to the main material and the main material is rigidly connected, and (b) shows the connecting material in the center part in two rows. (C) is a case where the connecting members in the central three rows are rigidly joined to the main material. It is a graph which shows the relationship between the vertical load in the curved truss center point, and the amount of bending. It is an elevation sectional view of a structure for explaining thrust power which acts on a structure which has an arch roof.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,50 Arch roof 2 Curved truss 3,51 Lower frame 4 End surface 5 Main material 5a End surface main material 6, 6 'Connection material 6a Outer connection material 7 Diagonal material 8 Brace 9 Steel pipe column 10 SRC column 11 SRC beam 12 Mat Slab 13 Pin support 14 Sliding plate 15 RC wall X Span direction Y Girder direction S Thrust force V Vertical load

Claims (3)

It is a frame structure of a structure having an arch roof whose span direction is arched,
The arch roof includes an arch-shaped main material that extends in the span direction and is juxtaposed in the longitudinal direction, a connecting material that is laid between the main materials, and a grid that is formed by the main material and the connecting material. A frame structure of a structure, characterized in that it is a curved truss composed of diagonal members arranged on the diagonal line of.   2. The structure according to claim 1, wherein the end face extending in the span direction of the structure has braces that support the curved truss in a truss shape on parallel columns. Frame structure.   3. The frame structure of the structure according to claim 1, wherein an end portion of the connecting member disposed in a center portion in the span direction of the curved truss is rigidly joined to the main member.

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