JPS6121269A - Steel rod truss build-in reinforced concrete pillar - 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 [Industrial Field of Application] The present invention relates to columns and windows of high-rise buildings, super high-rise buildings, or long-span structures, and reinforced concrete columns that are subject to large loads.

(Conventional technology) Conventional reinforced concrete columns have limited strength, especially toughness, and are susceptible to severe tremors caused by earthquakes.
It has the disadvantage that it is prone to cracking when subjected to reverse loads. Therefore, the current situation is that important columns such as those of high-rise buildings and large-scale structures are made of steel-framed steel M-concrete columns to compensate for their shortcomings.

[The point that the invention seeks to solve]

Reinforced concrete columns can generally withstand vertical loads up to quite large loads, but they are relatively weak against horizontal shear force, bending stress, and tensile loads caused by earthquakes, etc., and are susceptible to cracking, especially once A column with a shear crack was subjected to a vertical load and an earthquake at the same time! 1131 If a horizontal load is applied, the cracks will increase and there is a risk that the building will suddenly lose its strength and collapse.

As a countermeasure for this, the more 7-springs (tips) are placed densely, the more effective the shear reinforcement will be, and the sudden i
Although it is possible to prevent the spread of k-rupture and increase the toughness of the fence to some extent, there is a limit to this. In other words, the stirrup ratio used in the formula for calculating the allowable shear force of reinforced concrete columns is also t2%.
is set as the upper limit, and even if the shear strength is increased beyond that, the shear strength increases by 1% fh. In addition, placing a large number of 7-pipes densely in this manner not only increases construction time and the amount of steel required, but also impairs the filling properties of concrete. .

Therefore, important columns in high-rise buildings, super high-rise buildings, and large-scale structures with large spans that are subject to large loads can be constructed with steel-framed reinforced concrete or steel structures to increase their toughness, allowing them to withstand the intense repeated loads caused by earthquakes. It is common practice to ensure that the proof strength does not suddenly decrease and breakage occurs even if the material is subjected to such damage. However, compared to reinforced concrete construction, steel-framed reinforced concrete construction requires more labor and construction time, and the amount of steel required increases, making it difficult to construct.
Another disadvantage is that not only is it difficult to construct because the steel frames and reinforcing bars are intertwined in a narrow space, but also that the filling properties of concrete are poor, making it difficult to cast high-quality concrete with a small unit water volume.

On the other hand, iron-it columns are simple and inexpensive when used in light front buildings, but they are rather expensive for high-rise buildings with heavy loads, and require considerable construction costs for fire-resistant coating and anti-rust coating. It is.

[Means for solving problems]

In order to solve the above-mentioned drawbacks, in the present invention, as a substitute for steel-framed (hereinafter abbreviated as S-structure) columns among steel-framed reinforced concrete (hereinafter abbreviated as SRO-structure) columns, four I devised a four-dimensional pyramid-shaped truss by combining the M sticks of books, and decided to place this inside the pillar. Then, on the outside, main reinforcement and hoops are arranged parallel to the axis of the column, which corresponds to the reinforcement arrangement for reinforced concrete construction (hereinafter abbreviated as RO construction) of the SRO construction columns. .

[Effect]

The four steel rods 1 assembled as shown in the figure so as to intersect at the center of the internal height Ho of the upper and lower floor beams are regarded as a three-dimensional truss connecting two vertically symmetrical square pyramids with the intersection as the apex. be able to. Therefore, if an earthquake horizontal force is applied to this column, as shown in Figure 5, in response to an earthquake in the Horizontal shear force. 8, and diagonal earthquakes are resisted by the tensile force of one steel rod 1a and the compressive force of 1111, respectively. In either case, the horizontal shear force Q8 is completely absorbed by the tensile and compressive axial forces of the steel rod 1.
Shear, bending, and adhesive stress do not occur or are transmitted to the steel rod and the concrete surrounding it. In this case, if the steel bar is thick and has a large cross-sectional area, and if a steel material with a high yield point and tensile strength is used, the shear force Q8 borne by the steel bar truss can be increased accordingly.

Then, the residual QR = Q - Qa obtained by subtracting this Q8 from the total shear force Q applied to the column is the four corner main reinforcements 2, the intermediate main reinforcements 3 (hereinafter collectively referred to as parallel main reinforcements) and the hoop 4.
In addition, the shear force that is applied to the concrete that surrounds them, that is, the RO structure, is the burden of ordinary reinforced concrete, so the shear stress of the concrete is small and cracks do not occur. Moreover, fewer hoops are needed for shear reinforcement.

In addition, the shear force multiplied by the vertical height of the column appears in the sum of the column head and column base moments, but the bending moment also occurs in the parallel main reinforcement and concrete of the R0 structure at exactly the same ratio as the shear force above. The stress is reduced by the amount of stress that one truss has.

I have described the static stress distribution above, but what is particularly important for living shellfish is the difference in their resistance to large earthquakes. In other words, ordinary RO columns are hard and brittle, so if a shear crack develops in the concrete due to a major earthquake, the crack will expand if the column is subjected to a vertical load and then subjected to repeated loads due to an earthquake. and the strength will drop rapidly,
The so-called lack of tenacity and strength is a problem. ``On the other hand, the columns according to the present invention can withstand even if a small rack occurs in the concrete due to a large earthquake, or even if the tensile force of the parallel main reinforcement exceeds the yield point and the RO structure enters into a state of failure. Furthermore, since the steel bar truss resists large interstory deformation M in the elastic range, the increase in deformation is suppressed and damage to the concrete is prevented. In addition, the steel bar 1 has a large bend and forms a natte truss.
Even if the axial force of the column exceeds the yield load and enters the plastic region, it will continue to maintain its maximum yield strength and the strength of the column will not decline even if the amount of deformation is extremely large. A frame can be constructed. This was confirmed through model experiments.

〔Example〕

As shown in diagram M1, four steel bars 1 are connected to the lower surface of the upper floor beam and the upper surface of the lower floor beam, that is, the floor +6
The internal height of the column between 1 and Home is bent so that it is arranged diagonally and diagonally to the cross section of the column, and the top and bottom are connected with plate 5 to form a square pyramid shape to produce a trussm. . In this case, gas 1 is 1 in Figure 2! As shown by the arrow (----->') on the 'i' side, assemble the pillars so that they are slightly shifted from the diagonal of the pillars by the overlapping margin at the center of the pillars.

The steel 41!1 may be of any kind, such as round bar, deformed steel, square steel, flat steel, shaped steel, steel pipe, etc., but in this example, a large-diameter fully threaded reinforcing bar or a high-strength fully threaded PO steel bar is used. And,
If this is used, the nut can be moved anywhere, so the plate 5 can be easily fixed in a desired position by tightening the nut 6 from above and below, which is convenient. This plate 5 serves the purpose of forming the truss as well as an anchor plate to the panel zone of the steel bar 1. Further, by employing a fully threaded reinforcing bar or a fully threaded rail, the joints at the upper and lower ends can be easily and inexpensively constructed using a coupler 7 and a lock nut 8 or an injection definition method such as epoxy resin.

This steel bar truss is built one floor at a time and its joints are constructed, followed by four-corner main reinforcements 2 and, if necessary, the necessary amount of intermediate main reinforcements 3 and hoops 4. These parallel main bars 2 and 3 and 7-4 are installed on the outside of the truss A as pre-assembled reinforcing bars for the first floor height or the second to third floor height in a factory or on the ground, as shown in Fig. 4. You can also drop it from above to cover it.

After column reinforcement is placed, pass the girder main reinforcement through the panel zone of truss A and column reinforcing, wrap the hoop of the panel zone, arrange reinforcement for the girder stirrups, small beams, floor slabs, walls, etc., and construct the required formwork. , pour concrete and complete construction of the desired frame. In this case, it is effective to increase the strength and toughness by using ICX-type truss reinforcement for the girder as well as for the four columns.611 It is also possible to form the beam reinforcement into prefabricated reinforcing bars in advance and then arrange the reinforcement. can.

(Effects of the Invention) Although the outline has been described above, the effects, that is, the characteristics of the present invention will be summarized and listed at the end.

G) It has a higher yield strength than a Ho-built column, and even if the size of the column is the same, if you use high-strength large-diameter steel rods, you can obtain a column with a much higher yield strength.

IP) Especially against severe repeated dynamic loads caused by earthquakes,
This prevents cracking and failure of concrete, suppressing the increase in deformation, and even if deformation increases, there is little decrease in yield strength, resulting in a strong building or structure with high toughness.

e'9Next, if we compare this steel bar truss with f9RO-built steel columns, it goes without saying that the amount of steel required is less, but only four! Since the L rods are simply bent into a predetermined shape and assembled, the processing effort is incomparably less, and construction can be done cheaper and faster.

) Furthermore, this steel bar truss bears the majority of the shear force.
[5, therefore, the shear force shared by the Re structure is reduced, causing cracks in the concrete.

(A) Unlike 8RO construction, there is no confusion between steel frames and reinforcing bars, and since there is no need for wide steel frames, concrete filling properties are good and vibrators can be easily used. Therefore, it is possible to cast high-quality, hard-mixed concrete with a small amount of water per unit, making it easy to use high-strength concrete and achieve economical design with high yield strength. It also prevents the occurrence of cracks due to drying shrinkage, etc., improves the durability of concrete, and allows the construction of high-quality structures.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing how the steel materials of the column are assembled in an embodiment of the present invention, Fig. 2 is a cross-sectional view of the column, and Fig. 3 is the balance of forces when an earthquake horizontal force is applied to the steel bar truss. FIG. 4 is a perspective view of an assembled reinforcing bar made up of parallel main bars and 7-pipe. 1... Steel bar 2... Four corner main reinforcements 3... Intermediate main reinforcement 4... Hoop 5... Plate 6... Nut7...Kagura 8...Ptsukunuttom...Truss patent applicant Konoike Co., Ltd. Figure 3
Figure 4 Manabu Shiga, Director General of the Patent Office, P/3, 1939 1, Indication of the incident ↑ Temple Gansho Ri'-/S Di 2, Name of the invention 1-'7 'l, vi7 Enter Hab Comfleet Shibai L Name K1 Police Co., Ltd. (4Z) 4. Agent Figure 3

Claims (1)

[Claims] Truss ( Build A) and construct the joints at its upper and lower ends, arrange the four corner main reinforcements (2) and the necessary amount of intermediate main reinforcements (3) and hoops (4) on the outside, and pour concrete. A reinforced concrete column with a built-in steel bar truss.