JPH059364Y2 - - Google Patents

Description

[Detailed explanation of the invention] "Industrial application field" This invention relates to the frame structure of structures for warehouses, factories, etc. where roof load fluctuations are small, and in particular, the left and right column spans are 30m to 50m. This relates to the frame structure of a relatively wide structure.

``Conventional technology'' The structure type of the roof of a long span structure is as follows:
Various structures are used, such as a truss structure, a shell structure, a hanging structure, and an air membrane structure.

Among these, truss structures using long-span parallel chord truss beams are widely used because they have advantages such as not making the indoor space unnecessarily large and being easily adaptable to extensions.

``Problems that the invention aims to solve'' By the way, in the conventionally commonly used parallel chord truss, if its length becomes significantly large, the bending moment at the center increases and the amount of deflection also increases. There was a problem.

This idea was made in view of the above circumstances,
It is an object of the present invention to provide a frame structure for a structure that can reduce the bending moment at the center of a truss beam, equalize the stress generated at both ends and the center, and reduce the amount of deflection. .

"Means for Solving Problems" This invention consists of a triangular truss beam made of one upper chord member, two lower chord members, and a lattice member connecting them, and a left and right brace that supports both ends of the triangular truss beam. A frame structure of a structure comprising a plurality of main frames composed of columns, and suspension beams arranged parallel to each other and at predetermined intervals so as to be orthogonal to the plurality of main frames and to connect the triangular truss beams. The triangular truss beam is characterized in that prestress is introduced so that stress is applied in the opposite direction to that during vertical loading.

``Operation'' Figure 1a shows a main frame 3 to which the present invention is applied, which is composed of a triangular truss beam 1 and left and right pillars 2 supporting both ends of the triangular truss beam 1.

In the present invention, prestress is introduced to the triangular truss beam 1 so that stress is applied to the triangular truss beam 1 in the opposite direction to that during vertical loading.

That is, specifically, the steel frame is erected in a state where a tensile force is applied to the upper chord member 1a in advance. FIG. 1b shows the deformed state of the main frame 3 at that time, and FIG. 2a shows the stress state.

Further, FIG. 2b shows the stress state when a vertical load is applied to the main frame 3 without introducing prestress. Here, the stress M ₁ at the center of the triangular truss beam 1 is larger than the stress M ₂ at both ends.

FIG. 2 c is a composite of FIGS. 2 a and 2 b, and this figure shows a stress state in which a vertical load is applied to the main frame 3 to which prestress has been introduced. As can be seen from this figure, the stress M ₁ at the center of the triangular truss beam 1 and the stress M ₂ at both ends are approximately the same value, which ultimately reduces the maximum value of stress generated in the main frame 3. It is also possible to reduce the amount of deflection.

"Example" An embodiment of the present invention will be described below.

FIG. 3 is a perspective view of a main part of the frame structure of the structure according to the present invention, and numeral 11 in the figure indicates a main frame. The main frame 11 is a triangular truss beam 12
The triangular truss beam 12 is made up of one upper chord member 14, two lower chord members 15, 15, and a lattice member 16 connecting them. A plurality of main frames 11 having the above configuration are arranged parallel to each other at predetermined intervals.

Further, reference numerals 17 . . . indicate suspension beams, and these beams 17 are arranged parallel to each other and at predetermined intervals so as to be orthogonal to the plurality of main frames 11 and to connect the triangular truss beams 12. Further, in the case of this embodiment, the suspension beam 17 is firmly fixed to the lower chord member 15 so as to function as a component of the triangular truss beam 12.

The left and right pillars 13, 13 are composed of a pillar body 13a extending parallel to the lower chord member 15 of the triangular truss beam 12 at the same distance as the pillar body 13a, and a brace 13b extending between them.

Prestress (tensile force) is introduced into the upper chord member 14 so that stress is applied to the triangular truss beam 12 in a direction opposite to that during vertical loading.

That is, as shown in FIG. 4, the lower chord member 15 and lattice member 16 adjacent to the column 13 are fixed to a gusset 18, and the gusset 18 is pin-coupled to a bracket 19 attached to the column 13. Also,
A female threaded portion 14 is provided on the inner periphery of the end of the upper chord member 14 on the column 13 side.
A is formed, and an output side male threaded portion 20a of a jack 20 pin-coupled to the column 13 is screwed into this female threaded portion 14a. Introducing prestressing can be done when the top chord is 1 with a jack of 20 at the construction stage.
This is done by applying a tensile force to 4 in advance.

In the above embodiment, tensile force is applied to the upper chord member 14 through the jack 20 during construction, but prestress may be introduced by applying compressive force to the lower chord member 15 after construction. .

``Effects of the invention'' As explained above, according to the invention, prestress is introduced so that stress is applied to the triangular truss beam in the opposite direction to that during vertical loading, so that after construction, the central portion of the triangular truss beam is The stress at both ends can be set to be approximately equal. Therefore, the maximum value of the stress generated in the triangular truss beam can be reduced compared to the conventional one, and the yield strength can be improved accordingly, and the amount of deflection can be reduced.

In addition, the main frame is extremely strong, consisting of both strong triangular truss beams and braced columns, so it provides sufficient support for the suspension beams and the roof members supported by them. This allows the framework of the structure to be made using less material than conventional structures, provided the same strength is to be produced. Furthermore, the pitch of the suspension beam can be determined regardless of the pitch of the horizontal reinforcing steel members. Furthermore, since the suspension beam is a continuous beam, the number of members can be small compared to steel structures that are generally determined by deflection.

In addition, the triangular truss can be used for daylight and as a space for piping.

[Brief explanation of the drawing]

Figures 1a and b are deformation state diagrams of the main frame to explain the action of the invention, Figures 2a to c are stress diagrams to explain the action of the invention, and Figure 3 is an embodiment of the invention. FIG. 4 is a side view showing the prestress introduction part. 1,12...triangular truss beam, 2,13...column,
3, 11... Main frame, 17... Suspension beam.

Claims (1)

[Scope of utility model registration request] A plurality of main frames consisting of a triangular truss beam made of one upper chord member, two lower chord members, and a lattice member connecting them, and columns with left and right braces that support both ends of the triangular truss beam, and the plurality of main frames. and suspension beams arranged parallel to each other and at predetermined intervals to connect the triangular truss beams, the suspension beams being orthogonal to the main frame of the structure, wherein the triangular truss beams are loaded with is a frame structure of a structure characterized by the introduction of prestress to apply stress in the opposite direction.