JPH0747868B2 - Truss beam - Google Patents

Description

TECHNICAL FIELD The present invention relates to a truss beam particularly effective for use in a structure having a long span.

"Prior Art" As a frame structure having a long-span structure and a parallel string truss, various structures such as a truss structure and a shell structure are used.

By the way, in the case of parallel string trusses that have been commonly used in the past, when the span length is significantly increased, not only is the deflection increased, but the ratio of the weight of the truss to the total weight of the structure is increased, which is uneconomical. There was a problem that became.

Therefore, in order to solve such a problem, the present applicants use a truss member composed of an upper chord member, a lower chord member, and a lattice member, and use at least one of the above members (upper chord member, lower chord member and lattice member). We proposed a truss girder that introduces pre-stress by integrally attaching PC steel to the above members and tensioning and fixing the PC steel at both ends of the beam.

[Problems to be Solved by the Invention] The truss beam described above can prevent not only a large bending of the truss beam, but also reduce the weight of the truss beam to realize an economical frame. However, even with this truss beam, there is room for consideration, for example, in the following points.

The point that PC steel may move due to repeated loading.

The prestress is reduced due to the damage of the PC steel material, which affects the entire truss beam. In particular, if the PC steel material breaks, the prestress introduced in the truss beam will disappear.

An object of the present invention is to provide a new truss beam that can effectively solve the above problems.

"Means for Solving Problems" The present invention provides a truss member composed of an upper chord member, a lower chord member, and a lattice member, and at least one member extending in the span direction.
PC steel material is integrally attached, a truss beam introduced prestress by the tension of this PC steel material, in the middle of the PC steel material, a plurality of fixing plates along the length direction of the PC steel material,
It is provided in a state of penetrating the PC steel material, and the PC steel material is fixed on both sides of each fixing plate in a tensioned state by nuts screwed onto the outer periphery at a plurality of places in the middle of its entire length. It is characterized by having done.

[Operation] In the truss beam having the above-mentioned configuration, the PC steel material is fixed on both sides of each fixing plate by the nut screwed to the PC steel material outer periphery, so that the movement of the PC steel material with respect to the repeated load can be restricted. At the same time, even if one part of the PC steel material is cut, the other parts are fixed between the fixing plates and held in a state where tensile force is applied, so there is no effect on the entire truss beam. , You can minimize the loss of prestress.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

This truss beam 10 is mainly composed of an upper chord member 11 made of a steel pipe, a lower chord member 12 made of H-shaped steel, and a truss member which is assembled by a lattice member 13 made of a steel pipe and left and right belly members 14 connecting them. Has been done. And lower chord material 12
In addition, a plurality of fixing plates 15 are attached to both sides of the web at predetermined intervals, and pressure-bearing plates 16 are provided at both ends of the lower chord member 12, and the lower chord member 12 is penetrated through the fixing plate 15. A PC steel material 17 having a length over the entire length is integrally attached to the lower chord material 12. As this PC steel material 17, for example, PC
Steel wire, PC stranded wire, etc. are applied, and a cylindrical crimping grip (called condominium) 19 having a screw 18 on the outer peripheral surface is integrally formed by cold extrusion or the like at a position penetrating the fixing plate 15. This crimp grip can be crimped to
A pair of nuts 20 are screwed onto the fixing plate 15 with the fixing plate 15 interposed therebetween. And this PC steel material 17 is upper chord material 11 and lower chord material 1
2. After the lattice material 13 and the abdominal material 14 are connected to each other to complete the assembly, and after finishing materials and other equipment necessary for the function are installed, as shown by arrow A in FIG. While being tensioned and fixed to the bearing plate 16,
It is fixed to both sides of each fixing plate 15 via nuts 20. As a result, the truss beam 10 is prestressed by the compressive force applied by the PC steel material 17 in advance.

The truss beam 10 configured as described above can be adjusted by adjusting the prestress by the PC steel material 17.
Not only can the deflection of 10 be reduced, but also PC steel 17
It is possible to bear a part of the tensile load applied to the lower chord member 12 and to reduce the strength of the lower chord member 12 accordingly.

Further, in this truss beam 10, the fixing of the PC steel material 15 is performed by screwing the nut 20 into the male screw 18 of the crimp grip 19, so there is no set loss during tension fixing, slip after fixing, etc. Since there is no stress, it is possible to reliably introduce prestress.Because the PC steel material 17 is fixed by the nuts 20 from both sides of each fixing plate 15, the movement of the PC steel material 17 against repeated load should be restricted. Moreover, there is an advantage that the effect of fatigue due to repeated loading is extremely small.

Further, this truss beam 10 is the same as the conventional truss beam except that the PC steel material 17 is integrally attached to the lower chord member 12, and since it has sufficient rigidity by itself, 1 Even if the PC steel material 17 is cut, there is no risk that the truss beam 10 will fall. Moreover, in the present invention, since each PC steel material 17 is fixed for each fixing plate 15, even if any of these is cut, it does not affect the whole truss beam 10 and prestress loss occurs. Can be kept to a minimum.

Furthermore, this truss beam 10 is the same as the conventional one except that the PC steel material 17 is attached and the truss beam 10 is tensioned, and the conventional method can be used as it is.

Further, if the structure is such that the tensile force between the fixing plates 15 is changed to fix the PC steel materials 17 respectively, the prestress can be changed according to the stress state of the truss beam 10, and excess prestress can be introduced. It is possible to get an economical frame by eliminating things. As an operation for changing the tensile force of the PC steel material 17, for example, in the center of the span, with the tensile force for giving a prestress to be introduced, first, the central portion of the PC steel material 17 is fixed to the fixing plate 15. And fixer plate 15 on both sides
It is sufficient to apply a tensile force that is smaller than the tensile force at the center of the span in order for fixing each time.

FIG. 5 shows another embodiment of the present invention. Instead of the fixing plate 15 shown in FIG. 1 and the like, a pair of fixing plates 26 provided with a lube plate 25 for covering the pressure-bonding grip 19 is provided. , Lower chord material
It was attached to both sides of 12 webs.

In the case of this embodiment, the PC steel material 17 is a crimp grip.
19 is passed through the rib plate 25, and is fixed by the nut 20 from above the pair of fixing plates 26, and has the same effect as the above-described embodiment.

The truss beam 10 of the embodiment of the present invention has been described above, but the present invention is not limited to the above. For example,
In the above embodiment, the truss beam 10 has the PC steel material 17 attached only to the lower chord member 12, but even if it is attached to the upper chord member 11,
Alternatively, it may be attached to both of them.
Further, the shape and assembly method of the truss beam 10 may be appropriately selected, and the upper chord member 11, the lower chord member 12, the lattice member 13, and the belly member 14 are made of steel pipe or H
The steel is not limited to the shape steel, but may be an appropriate steel material such as an I-shape steel or a T-shape steel, or may be wood or the like.

Further, in the drawings of each of the above-mentioned embodiments, the sheath pipe is omitted from the PC steel material 17, but this PC steel material 17 is a sheath pipe, and when the PC steel material 17 is assembled, the PC steel material 17 is attached to the outer periphery of the PC steel material 17 together. After uncovering and tensioning, the unbonded method of filling grease or mortar into the sheath tube, or attaching the shear cotter and the sheath tube to the truss material first and making them integral with concrete, and after tensioning, mortar the sheath tube. By using the grout bond method, etc.,
Anti-corrosion treatment is performed.

As described above, according to the present invention, the PC steel material is integrally attached to at least one of the upper chord member and the lower chord member, and the fixing plate penetrating the PC steel member in the middle of the PC steel member is A plurality of PC steel materials are arranged along the length direction, at a plurality of places in the middle of the entire length, by nuts screwed onto the outer periphery thereof,
Since each of the fixing plates was fixed on both sides in a tensioned state, it is possible to regulate the movement of the PC steel material against repeated load, and even if a part of the PC steel material is cut, the other part is between the fixing plates. Since each of the truss beams is fixed and held in a state where a tensile force is applied, it does not affect the entire truss beam, and the loss of prestress can be minimized.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention.
FIG. 1 is a side view of the truss beam, FIG. 2 is a side view showing the configuration of the central portion of the truss beam, FIG. 3 is a sectional view taken along the line III-III in FIG. 2, and FIG. FIG. 5 is a side view of a fixing portion showing another embodiment of the present invention. 10 …… Truss beam, 11 …… Upper chord, 12 …… Lower chord, 13 ……
Lattice material, 14 ... Belly material, 15 ... Fixing plate, 16 ... Bearing plate,
17 …… PC steel material, 18 …… Male screw, 19 …… Crimping grip, 20
...... Nut, 25 …… Clad tube, 26 …… Fixing plate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Ritsuyuki Kato 2-16-1, Kyobashi, Chuo-ku, Tokyo Within Shimizu Construction Co., Ltd. (72) Inventor, Shuji Okuda 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Hideo Shimomura 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Honda Kyushu 2--16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Ken Incorporated Co., Ltd. (72) Inventor Masato Kawaguchi 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu K.K.Incorporated (72) Inventor Kuno Kasuo 2-16-1 Kyobashi, Chuo-ku, Tokyo Constructed Shimizu Co., Ltd. (72) Inventor Takeki Kumagai 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Tetsuo Aoyama 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. Inside the company (72) Kenichi Sugisaki 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Tadayoshi Fujii 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor, Kido, 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor, Hiroshi Ueda, 2--16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction ( 72) Inventor Kazunori Koshida 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Kunio Mogi 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Construction (72) Inventor Nobuo Kato 2-16-1, Kyobashi, Chuo-ku, Tokyo Within Shimizu Construction Co., Ltd. (56) References Japanese Patent Publication 6-21491 (JP, B2)

Claims (1)

[Claims] 1. A truss member composed of an upper chord member, a lower chord member, and a lattice member. PC steel is integrally attached to at least one member extending in the span direction, and prestress is introduced by tension of the PC steel. The truss beam that has been
In the middle of the steel material, a plurality of fixing plates are provided along the length direction of the PC steel material in a state of penetrating the PC steel material, and
A truss beam, wherein the PC steel material is fixed in a tensioned state on both sides of each of the fixing plates by nuts screwed onto the outer periphery of the PC steel material at a plurality of positions along the entire length thereof.