JPH0222821B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a roof frame, particularly a space frame dome constructed of beams and cables.

Conventional technology Traditionally, as roof structures with large spans, (1) reinforced concrete shell structures, (2) steel space frames such as lamellas and geodesic domes, (3) air membrane structures, and (4) cable suspension structures have generally been used. is known,
Prior art to this invention is U.S. Patent No. 4052334.
There is a number. That is, (5) there is a roof structure in which a tube serving as a compression member is used as the upper chord member and a cable serving as a tension member is used as the lower chord member to curve upward with a beam frame in one direction.

Problems to be Solved by the Invention In the above-mentioned conventional technology, (1) is made of reinforced concrete, which is heavy and requires temporary materials such as temporary frames, supports, and scaffolding, resulting in a long construction period and high cost. (2) requires temporary materials such as scaffolding and is troublesome to assemble, and (3) has the advantage of being lightweight and requiring a short construction period, but requires constant ventilation and maintenance. Management is complicated, and although (4) can be made into a long span, it has the disadvantage that the finishing material that forms the roof surface is subject to deformation, and (5) is a one-way beam structure, so it is rectangular. However, it was not possible to construct a dome-shaped roof structure.

The present invention is an economical space frame dome that does not have these drawbacks, is lightweight, does not require temporary materials, and has a rational member structure, and is highly constructible. The idea is to provide a large space of pillars.

Means for Solving the Problems The means of the present invention for solving the above problems is a dome constructed of beams and cables, in which the upper chord is a steel beam, the lower chord is a cable, and the web member is a steel frame. The steel beams are fixed radially to the annular member, the cable has its inner end attached to the annular member, its middle part is attached to the lower end of the steel bundle, and its outer end is attached to the tip of the steel beam. The cable consists of a beam and a cable that are stretched under tension between an annular member and the tip of the steel beam so that the steel beam curves into a dome shape.

Embodiment An embodiment of the present invention will be described with reference to the drawings.

Reference numeral 1 designates steel beams serving as upper chord members of the space frame, which are arranged radially around an annular member 2 as shown in FIG.
is fixed. Reference numeral 3 denotes a cable serving as a lower chord member, and a supporting metal fitting 5 at the lower end of a steel beam bundle 4 serving as a web member provided at a suitable location in the middle of the steel beam 1 (see Fig. 6).
(Fig. 7), and its inner end 6 is movably inserted into the annular member 2 as shown in Fig. 5.
As shown in FIG. 8, its outer end is movably inserted into a support fitting 8 at the tip of the steel beam 1 and fixed with a wedge 9. The annular member 2 is provided with an opening for opening and closing the roof surface, and is used as a space for lighting or ventilation.

Alternatively, the outer end of the cable 3 may be fixed to a mounting portion at the tip of the steel beam 1, and the inner end thereof may be pulled out through the support of the annular member 2 toward the center.

To make the dome of this example, the steel beams 1, the annular member 2, the cables 3, and the steel bundles 4 are arranged on the ground or near the roof eaves as shown in Figures 1 and 4. Assemble the ground at the location. Next, when tension is introduced by pulling the cable 3 inserted through the support fitting 8 at the tip of the steel beam 1, the cable is tensed in a straight line as shown in Fig. 2, and a compressive force and a bending moment act on the steel beam 1, causing a slight bending moment. It curves and begins to rise. When the cable 3 is further pulled, the compressive force and bending moment of the steel beam 1 are
Further, since the tensile force of the cable 3 is transmitted to the member at the other end via the annular member 2, the tensile force of the cable 3 forms a curved surface as shown in FIG. When a predetermined curved surface is reached, the outer end of the cable 3 is fixed to the support fitting 8 of the steel beam 1 with a wedge 9, as shown in FIG. It is fixed to complete the dome.

Effects of the Invention This invention has the most rational member structure from a mechanical point of view, with the upper chord being subjected to compression and bending, and the lower chord being subjected to tension, and can be designed at low cost. Since the structure has steel beams installed radially, it is possible to create a dome with a large diameter that is approximately twice the length used in one span, and the simple structure makes it extremely easy to construct. good. The dome can be assembled close to the ground with good precision, and since the center of the dome is an annular member and the inside is empty, an opening can be provided on the roof to let in light as needed. This is advantageous for use as a dome as it allows ventilation.

[Brief explanation of drawings]

The drawings show one embodiment of the invention.
Figures 1 to 3 are explanatory diagrams of only one span viewed from the front. Figure 1 shows the state when the ground assembly is completed, Figure 2 shows the steel beam in a slightly curved state due to the cable being pulled, and Figure 3 shows the steel beam slightly bent. Figure 4 shows the completed dome curved surface, Figure 4 shows the same state as Figure 1, the right half is a plan view, the left half is a bottom view showing the cable and steel bundle, and Figure 5 is an enlarged cutaway of the left half of the annular member. 6 is an enlarged side view showing the attachment of the support fittings, FIG. 7 is a front view, and FIG. 8 is an enlarged front view showing the tip of the steel beam. 1... Steel beam, 2... Annular member, 3... Cable, 4... Steel bundle, 6... Inner end.

Claims (1)

[Claims] 1 The top chord is steel beam 1, and the bottom chord is cable 3.
The web material is composed of a steel beam bundle 4, the steel beam 1 is radially fixed to the annular member 2 at the center, the cable 3 has its inner end 6 attached to the annular member 2,
Its middle part is attached to the lower end of the steel beam bundle 4, and its outer end is attached to the tip of the steel beam 1,
The cable 3 is a dome composed of a beam and a cable, which are stretched under tension between the annular member 2 and the tip of the steel beam 1 so that the steel beam 1 is curved into a dome shape.