JPS60188579A - Cable arrangement in air film structure roof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to the provision of a novel cable arrangement in a pneumatic membrane roof.

The air membrane structure is a structure in which cables are stretched across the roof surface in a cross-shaped net shape, and the membrane N4 is fixed to the squares around the four circumferences, and when the membrane material has been stretched on the roof surface, it can be installed indoors. air is introduced into the room, and the indoor air pressure is reduced to 0 from atmospheric pressure.
．． This is an air support structure that inflates the roof surface by increasing the pressure to 0.025 atm (25 kg/m), and the conventional technology for arranging the cables is often two-way arrangement.

In the United States, this two-way arrangement is the most convenient cable arrangement when the plan shape of the building is rectangular or super elliptical, as it minimizes bending stress on the compression ring as a boundary structure. It was adopted.

There are over a dozen examples of this two-way gable in the United States, and it has been gradually improved with each building, but some problems remain.

First, in the air-the-boat structure, which obtains a balanced curved surface by internal pressure, the shape is easily changed by wind or snow after the shape is determined, as shown in Figure 1. Geometric nonlinear analysis must be carried out under the conditions that maintain the . It cannot be manufactured and the manufacturing cost is relatively high. The reason for this is 2.
The membrane sections created by directional cable arrangement have the same dimensions in the projected plane, but because the roof is a curved surface, the dimensions of each crotch panel actually manufactured differ slightly.

In order to solve this problem, there is a case in the United States where the dimensions of membrane production were purposely standardized, but in this case the roof did not have the expected curved surface, but instead became flat, so when it snowed, snow accumulated in the center and the roof fell down. There was an accident in which roof panels were damaged, and the ones that have been built since then have used the traditional method again, and instead of standardizing the dimensions of the roof panels, they are manufactured one by one based on predetermined dimensions and shapes.

Second, there were cases in which two-way cables were placed on the entire roof surface, but the cable length was shorter in the peripheral area, and the cable tension was not large, so the peripheral cable was omitted to reduce the number of cables. are increasing. This has the advantage of reducing roof construction costs and roof weight, but on the other hand, judging from the material strength of the membrane material, the diamond-shaped part in the center can bear membrane stress in two directions. The rectangular portion at the periphery bears membrane stress in the short side direction.

Therefore, in the rectangular part, the membrane material is designed based on the uniaxial allowable stress of the membrane material, and when using the same membrane material,
The crotch panel in the diamond-shaped area is over-designed.

Thirdly, although the two-way cable arrangement is arranged at approximately the same intervals, in an extremely large roof area, the maximum wind load on the roof surface also differs depending on the roof area, and the mirror panels cannot have the same stress.

This results from the two-way equally spaced cable arrangement.

The present invention has been made in view of the above problems.

The gist of this is that cables are arranged radially and concentrically, and the radial cables arranged at the periphery are thinned out in number towards the center, and the cables are arranged in square sections made up of these cables. Assuming that the membrane material is used (= Jru), we will standardize the shape and dimensions of the membrane panels as much as possible, reduce the number of membrane panels relative to the roof area, streamline and economize production, and reduce the use of membranes and cables. In order to make the most of the allowable stress, the membrane bears a considerable amount of biaxial stress, and the cables are of the same size, making it possible to equalize the tension distribution. This will be explained in detail below based on the figures.

In other words, in the United States, there are many stadiums with a 11-roof roof built for games such as funtoball, and the shape of the 11/- surface is often rectangular or super elliptical, but in Japan, baseball is the main sport. , often have a nearly circular plane.

Therefore, assuming this planar shape, it is possible to use both the radial cable arrangement a and the concentric rigid cable arrangement b, as shown in FIG.

However, this concentric and radial cable b,
The arrangement a can be set in the middle of the membrane panel in order to make maximum use of the allowable stress of the crotch + and l in the circumferential part, but the distance between the radial cables a becomes narrower towards the center. , IIQ area is small and the stress existing in the crotch is small,
In addition to not being able to economically utilize the strength of the IQ Shrine,
As the number of IIQ panels increases, the number of cables, membrane materials, hardware, etc. also increases unnecessarily, making it uneconomical.

For this reason, regarding the air membrane structure cable arrangement composed of concentric cables b and radial cables a, the radial cables a are thinned out in the center, and the cable sections in the center are made into appropriate sections.

Note that O in Figure 3 indicates a complex or a John ring as a boundary structure.

By adopting this method of configuring a multi-stage ring-shaped equally spaced zone, the allowable stress of the membrane material C can be maximized, and the number of different types of panels can be reduced. By standardizing panel manufacturing dimensions, it becomes possible to produce economically.

Next, what is shown in FIGS. 3 and 4 relates to an improvement of the invention shown in FIG.

That is, when implementing what is shown in FIG. 2, it may be necessary to provide a strong Jili method that meets each design condition for practical use.

The first reason is that cables are arranged radially and concentrically, and in radial cables, as the cables arranged at the periphery move toward the center, the spacing between the cables becomes closer, so stress conditions cannot be taken into account. However, when actually thinning out radial cables, in order to transmit the tension at the ends of the thinned-out cables to the concentric cables, it is necessary to use restraining hardware with a considerably large binding force. Unless the cable is fixed to the concentric cable, the end of the cable cannot be restrained, and a joining method using such a large restraining metal fitting is impractical.

The second reason is that when the radial cable and concentric cable are joined in a T-shape, the stress state applied to the membrane material is the same as that of the two-way cable net system used in the conventional air membrane structure. In contrast, considerable concentrated stress acts on the membrane material on the opposite side of the thinned-out radial cable terminal, resulting in a result different from the initial intention, which was to equalize the stress in the membrane material.

In order to solve this problem, it is necessary to rationally handle the tensile force generated at the end of the radial cable to be thinned out.
Must be.

In this process, as shown in FIG. 3, the thinned out radial cable a° is extended by 2 minutes d, and then the next adjacent radial cable a or a is extended.

If the concentric cable b intersects with the concentric cable b, or if it is thinned out as shown in Figure 4, the concentric cable b
There is a method of dispersing the tensile force by extending and fixing the concentric cable b in the center without immediately terminating it at the intersection with the concentric cable b.

In either case, the purpose of the extension cables is to process the cable tension in stages, and the extension cables d and e are not fixed to the membrane material C, rather than subdividing the membrane material C. It extends to the next concentric cable b near the center and is restrained.

By doing this, the stress treatment at the end of the thinned radial cable a becomes smooth, and the I
Excessive concentrated stress does not act on IR stress either.

In the embodiment shown in FIG. 4, in order to manage the stress at the center, the radial cable a connected from the outermost circumference to the concentric cable at the innermost core is further extended e and connected to the center point O. It is gathered at.

Similar processing may be performed in the case of FIG.

[Brief explanation of the drawing]

Fig. 1 is a roof curved surface diagram based on geometric nonlinear analysis, Fig. 2 is a plan view showing the cable arrangement of the present invention, and Figs. 3 and 4 show cable arrangement improved from the cable arrangement shown in Fig. 2. FIG. 1...Membrane, 2...Cable interval l-, a...Radial one pull, al...Radial cable, b...Concentric cable, C...Membrane material, d...Extension cable,
e...Extension cable/door/Δ Dodo 1 Nfu 21 Nobu 34η Sakae'l'4Aη

Claims (3)

[Claims] (1) U--puls are arranged radially and concentrically,
An air membrane structure roof characterized in that the radial cables arranged at the circumference i22 are thinned out in number toward the central part, and the membrane material is attached to the square sections formed by these cables. Cable arrangement at. (2) Cables are arranged radially and concentrically, and the radial cables arranged at the periphery are thinned out in number toward the center, and the membrane material is installed in the square sections formed by these cables. In the old cable arrangement, the thinned out radial cable is stretched in half without being fixed to the membrane material, and the next radial cable next to it is fixed at the part where it intersects with the concentric cable. lI: LJ cable arrangement on an air membrane structure roof characterized by: (3) Cables are arranged radially and concentrically, and the number of radial cables arranged at the periphery is thinned out toward the center, and the monthly divisions formed by these cables are arranged. An air membrane structure characterized in that when thinning out a cable arrangement in which a single shrine is attached to a cable, the cable is not immediately terminated at the intersection with the concentric cable, but is further extended and fixed to the concentric cable in the center. Cable arrangement on the roof.