JP2010248725A - Base plate for steel-pile column - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base plate for a steel-pipe column which suppresses an increase in total weight while increasing strength. <P>SOLUTION: The rectangular base plate 100 for the steel-pipe column includes a rising portion 20 which is formed in a central portion, an anchor bolt seat 30 which is formed toward a corner 11, and a triangular inclined portion 40 which is sandwiched by the anchor bolt seat 30. The inclined portion 40 comprises: a low slope 41 which is a part of a surface connecting a position E as a plate thickness (T2) determined from the compression of concrete in the application of temporary allowable strength, and a position D as a plate thickness (T0) determined by restrictions on the manufacturing of a peripheral edge 12 of the inclined portion 40; and a steep slope which is a part of a surface connecting a position F as a plate thickness (T3) determined by the compression of the concrete in the application of temporary allowable strength as a value higher than the temporary allowable strength, and a position C of a bottom surface 10 of the peripheral edge 12. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  TECHNICAL FIELD The present invention relates to a steel pipe column base plate, and more particularly to a steel pipe column base plate installed on high-strength foundation concrete formed by high-strength concrete as compared with a normal concrete foundation.

The steel pipe column base plate used for the exposed column base method to fix the steel column to the foundation concrete is a rectangular plate material, and an annular upright formed at the center to join the lower end of the steel column An anchor bolt seat formed with an anchor bolt hole through which the anchor bolt is inserted, and a substantially triangular inclined portion sandwiched between the anchor bolt seats; have.
And the arrangement | positioning of an anchor bolt is prescribed | regulated and the base plate for steel pipe pillars which can make thickness as small as possible is disclosed (for example, refer patent document 1).

JP 2000-282570 A (page 3-4, FIG. 1)

In the invention disclosed in Patent Document 1, the thickness (T1) of the anchor bolt seat portion is set against the bending moment generated at the joining position with the upright portion of the anchor bolt seat portion due to the yield axial force of the threaded portion of the anchor bolt. Thus, it is determined from the condition that the joining position stays within the elastic range.
On the other hand, the thickness (T2) at the position close to the upright part of the inclined part (same as the apex of the triangle) is the bending moment generated at the close position to the upright part of the inclined part due to the compression of concrete at the short-term allowable strength. On the other hand, it is a value determined from the condition that the closest position stays within the elastic range.
Further, the minimum value of the thickness (T0) at the peripheral edge of the inclined portion (same as the base of the triangle) is determined from manufacturing restrictions (for example, a thickness that guarantees a molten metal flow during casting).
At this time, the inclined portion has a flat surface inclined from the peripheral edge portion (thickness T0) toward the closest position (plate thickness T2).

Therefore, the invention disclosed in Patent Document 1 has the effect of reducing the thickness of the steel pipe column base plate as much as possible, but the inclination angle of the inclined portion varies depending on the value of the short-term allowable strength of concrete. become.
That is, when trying to change the steel pipe column base plate installed in concrete with a predetermined strength to the steel tube column base plate installed in concrete with higher strength than this, the latter inclination is more than the inclination angle of the former inclination part. The inclination angle of the portion becomes larger, the thickness of the entire inclined portion increases, and the overall weight of the steel pipe column base plate increases.
For this reason, there has been a demand to suppress an increase in the overall weight of the steel pipe column base plate installed on the higher-strength concrete.

  SUMMARY OF THE INVENTION The present invention is intended to provide a base plate for a steel pipe column that meets such a demand and is installed on concrete having higher strength, and that suppresses an increase in the overall weight.

(1) The steel pipe column base plate according to the present invention has a substantially rectangular shape installed on the foundation concrete by anchor bolts fixed to the foundation concrete,
An annular upright formed at the center and joined to the lower end of the steel pipe column;
An anchor bolt seat formed with an anchor bolt hole through which the anchor bolt is inserted, formed from the upright portion toward the corner along the diagonal line;
A substantially triangular inclined part sandwiched between the anchor bolt seat parts,
A gentle slope is formed near the peripheral edge of the slope,
A steep slope is formed near the center of the slope.

(2) Further, in (1), the gentle slope is determined from a condition in which the close position stays within an elastic range with respect to a bending moment generated in the close position by compression of concrete at a short-term allowable yield strength. A surface connecting the upper surface at the closest position of the plate thickness (T2) and the upper surface of the plate thickness (T0) determined from manufacturing restrictions at the peripheral edge of the inclined portion,
The steep slope is determined from a condition in which the close position stays within an elastic range with respect to a bending moment generated at the close position by compression of concrete at a short-term allowable load having a value larger than the short-term allowable load. It is a surface connecting the top surface at the closest position of (T3) and the bottom surface at the peripheral edge of the inclined portion.

  The steel pipe column base plate according to the present invention is formed with a gentle slope and a steep slope in the inclined portion, that is, the thickness is limited to the minimum necessary range corresponding to the strength increase. In contrast to the case of forming a flat surface, it is possible to delete an unnecessary thickness in terms of strength, and the overall weight can be reduced. In addition, when manufacturing by casting, it is necessary to modify existing molds (metal molds, wooden molds, etc.) within the minimum necessary range to increase the strength. Therefore, the manufacturing cost of the mold can be suppressed.

The top view etc. which explain the base plate for steel pipe columns concerning Embodiment 1 of the present invention. The expanded sectional view explaining the base plate for steel pipe columns shown in FIG. The top view explaining the base plate for steel pipe pillars which concerns on Embodiment 2 of this invention.

[Embodiment 1]
1 and 2 illustrate a steel pipe column base plate according to Embodiment 1 of the present invention. FIG. 1 (a) is a plan view, FIG. 1 (b) is a side view, and FIG. (C) is a sectional view, and FIG. 2 is an enlarged sectional view.

  In FIG. 1, a steel pipe column base plate 100 is installed on foundation concrete by anchor bolts (not shown) fixed to the foundation concrete (not shown). The steel pipe column base plate 100 is substantially rectangular and has a flat bottom surface 10, an annular upright portion 20 formed in the center, and diagonally extending from the upright portion 20 toward the corner portions 11a, 11b, 11c, and 11d. The anchor bolt seats 30a, 30b, 30c, and 30d are formed.

(Inclined surface)
And it has the substantially triangular inclined part 40a, 40b, 40c, 40d pinched | interposed into the anchor bolt seat part 30a, 30b, 30c, 30d. In the following, common contents will be described by omitting the reference numerals “a, b, c, d”.
The anchor bolt seat portion 30 has an anchor bolt seat upper surface 31, an anchor bolt seat side surface 32, and an anchor bolt hole 33 that penetrates (passes through the anchor bolt seat upper surface 31 and the bottom surface 10).
Further, a gentle slope 41 is formed near the peripheral edge portion 12 of the inclined portion 40, and a steep slope 42 is formed near the rising portion 20 of the inclined portion 40 (the same as the central portion). In addition, the peripheral part protrusion 13 for positioning is formed in the center of the peripheral part 12. As shown in FIG.

(Slow slope)
In FIG. 2, the condition that the gentle slope 41 stays in the elastic range with respect to the bending moment generated at the closest position (same as the position indicated by BB) due to the compression of the concrete at the short-term allowable strength. The upper surface (indicated by position E) of the plate thickness (T2) determined from the upper surface (indicated by position E) and the upper surface (position D of the plate thickness (T0) determined from manufacturing restrictions in the peripheral portion 12 of the inclined portion 40) Part of the surface connecting

(Steep slope)
In addition, the steep slope 42 has a close position with respect to a bending moment generated at the close position (same as the position indicated by BB) due to the compression of the concrete when the short-term allowable load is larger than the short-term allowable load. The top surface (indicated by position F) of the plate thickness (T3) determined from the condition of staying within the elastic range (indicated by the position F) and the position of the bottom surface 10 (position C in the peripheral edge protrusion 13). Part of the surface connecting

That is, the strength of the foundation concrete is secured by increasing the thickness of only the portion necessary for reinforcement, corresponding to the case where the strength of the foundation concrete is increased. At this time, while maintaining the basic shape of the existing basic concrete (before the strength of the basic concrete is increased) as much as possible, the strength is increased and the weight increase (increase in the amount of material) due to the smallest increase in cross-section is suppressed. It has become.
In addition, it is possible to cast foundation concrete with increased strength by modifying the molds (molds, wooden molds, etc.) for casting existing foundation concrete to the minimum range, so that the production cost is reduced. It will be cheaper.
The present invention does not limit the calculation formulas of the plate thickness (T2) and the plate thickness (T3), and for example, the following well-known formula may be used (see Patent Document 1). Further, the upright portion 20 has a rectangular cross section (a steel column made of a square steel pipe is joined), but the present invention is not limited to this, and the upright portion 20 has a circular cross section (a steel frame made of a round steel pipe). The columns may be joined).

[Embodiment 2]
FIG. 3 is a plan view for explaining a steel pipe column base plate according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected to the part same as Embodiment 1, or an equivalent part, and one part description is abbreviate | omitted. In addition, for the common contents, the description of the subscripts “a, b, c, d” is omitted.
In FIG. 3, the steel pipe column base plate 200 has a pair of anchor bolt holes 33 formed in the anchor bolt seat portion 30. Further, an angle inclined portion 50 whose thickness decreases toward the corner portion 11 is formed near the corner portion 11 of the anchor bolt seat portion 30.
At this time, since the inclined portion 40 is formed of the gentle slope 41 and the steep slope 42 as in the first embodiment, the same effect as in the first embodiment can be obtained.

  The present invention is as described above. Since the strength can be increased while suppressing the increase in weight and the manufacturing cost, it can be widely used as a base plate for various types of steel pipe columns.

DESCRIPTION OF SYMBOLS 10 Bottom surface 11 Corner | angular part 12 Peripheral part 13 Peripheral part protrusion 20 Standing top part 30 Anchor bolt seat part 31 Anchor bolt seat upper surface 32 Anchor bolt seat side surface 33 Anchor bolt hole 40 Inclined part 41 Slightly inclined surface 42 Steeply inclined surface 50 Angle inclined part 100 For steel pipe pillars Base plate 200 Base plate for steel pipe column

Claims (2)

A base plate for a substantially rectangular steel pipe column installed on the foundation concrete by anchor bolts fixed to the foundation concrete,
An annular upright formed at the center and joined to the lower end of the steel pipe column;
An anchor bolt seat formed with an anchor bolt hole through which the anchor bolt is inserted, formed from the upright portion toward the corner along the diagonal line;
A substantially triangular inclined part sandwiched between the anchor bolt seat parts,
A gentle slope is formed near the peripheral edge of the slope,
A steel pipe column base plate, wherein a steep slope is formed near the center of the inclined portion. At the close position of the plate thickness (T2) determined by the condition that the close position stays within the elastic range with respect to the bending moment generated at the close position due to the compression of the concrete at the time of short-term allowable yield strength A surface connecting the upper surface and the upper surface of the plate thickness (T0) determined from manufacturing restrictions in the peripheral portion of the inclined portion,
The steep slope is determined from a condition in which the close position stays within an elastic range with respect to a bending moment generated at the close position by compression of concrete at a short-term allowable load having a value larger than the short-term allowable load. 2. The steel pipe column base plate according to claim 1, wherein the base plate is a surface connecting the upper surface at the closest position of (T3) and the bottom surface at the peripheral edge of the inclined portion.

Images