JP5956893B2 - Column base hardware and column base structure using the same - Google Patents

Description

  The present invention relates to a column base hardware in which a lower end portion of a pillar member in a building structure is joined thereon and a tip end portion of an anchor bolt protruding upward from the foundation concrete is fastened, and a column base using the same. Concerning structure.

  FIGS. 9 and 10 are views referred to for describing the first conventional column base metal 6 and the first conventional column base structure 2 using the same.

  As shown in FIG. 9, the first conventional column base structure 2 was provided with a plate-shaped column base metal 6 to which the lower end surface of a steel column 4 (column member) was joined by welding. This column base metal 6 was provided above the foundation concrete 3 via a mortar 8.

  And the upper end part of the anchor bolt 10 which protrudes upwards through the mortar 8 from the foundation concrete 3 is inserted into the bolt insertion holes 6a and 6b (see FIG. 10) of the column base metal 6 to form the anchor bolt 10. When the internal thread portion of the nut member 12 is screwed to the external thread portion, the steel column 4 is erected and fixed on the foundation concrete 3 via the column base metal 6 (for example, Patent Document 1). reference).

  A coated concrete 11 was formed on the basic concrete 3. This covering concrete 11 has an upper surface at a position higher than the height upper end position of the upper end of the anchor bolt 10, the lower end of the steel column 4, the column base 6, the mortar 8, the upper end of the anchor bolt 10, Each member such as the nut member 12 is embedded therein.

  As shown in FIG. 10, the column base metal 6 is formed in a plate shape having a thickness and both sides of a metal square shape and penetrates in the thickness direction (perpendicular to the paper surface in the figure). Twelve bolt insertion holes 6a and 6b were formed. These bolt insertion holes 6a and 6b are formed to have substantially the same diameter, and one anchor bolt 10 is loosely inserted into each of them.

  Then, one bolt insertion hole 6 a of the column base metal 6 is formed at each of the four corners of the square shape of the column base metal 6. That is, the bolt insertion hole 6a of the column base 6 extends in the left-right direction in FIG. 10 and extends from the virtual line X passing through the center position in the vertical direction of the column base 6 in the vertical direction in FIG. L1 away from the imaginary line Y that extends in the vertical direction in the figure and passes through the center position of the column base 6 in the horizontal direction in the figure, by a length L1 in the horizontal direction in the figure. The center position was arranged at each of the four positions.

  The bolt insertion holes 6b of the column base metal 6 are arranged at equal positions in the length direction between the bolt insertion holes 6a and 6a at both ends of each of the four square sides of the column base metal 6. That is, the respective center positions are arranged at two positions obtained by dividing the line segment connecting the centers of the bolt insertion holes 6a and 6a into three equal parts.

  The bolt insertion hole 6b is, for example, at two sides extending in the vertical direction in FIG. 10 at a position separated from the virtual line Y by a length L1 in the horizontal direction in the figure, and from the virtual line X in the vertical direction in the figure. The respective center positions are arranged at positions separated by the respective lengths L2. The length L2 is one third of the length L1. In two side portions extending in the left-right direction in FIG. 10, the bolt insertion holes 6b are arranged at the same length position.

Japanese Patent No. 4006503

  For example, due to an earthquake or the like, the steel column 4 of the first conventional column base structure 2 is bent around the rotation center O of the joint between the steel column 4 and the column base metal 6 as shown in FIG. When a load that generates a large bending moment M for rotating the steel column 4 in the clockwise direction is applied, the bending moment M lifts the right end of the column base 6 in the figure. Works.

  On the other hand, the anchor bolt 10 for fixing the right portion of the column base metal 6 from the rotation center O in FIG. 9 is fastened by screwing the male screw portion and the female screw portion of the nut member 12 as described above. As a reaction force for preventing the right end portion of the column base metal 6 from being lifted by the bending moment M, the tensile load P1, which is located at the positions of the lengths L1, L2 in the right direction in the drawing from the rotation center O in the drawing. P2 is generated.

  The tensile loads P1 and P2 generated as the reaction force increase as the anchor bolt 10 increases in length L1 and L2 in the right direction in the drawing from the rotation center O shown in FIG. 9, and the outer diameter of the anchor bolt 10 increases. The larger the is, the larger it becomes.

  However, in the first conventional column base structure 2, it is generated in the anchor bolt 10 inserted and fixed to the bolt insertion hole 6 b at a position separated from the rotation center O by the length L 2 in the right direction in FIG. The tensile load P2 is a tensile load having a considerably smaller value than the tensile load P1 generated in the anchor bolt 10 that is fixedly inserted through the bolt insertion holes 6a and 6b at a position separated from the rotation center O by the length L1. End up.

  Accordingly, there exists an anchor bolt 10 that can generate only a considerably small tensile load P2 as described above as a tensile load (correlating with a bending strength with respect to the bending moment M) generated in the anchor bolt 10 against the bending moment M. For this reason, there is a problem that the bending strength of the column base structure 2 with respect to the overall tensile load, that is, the bending moment M, is reduced accordingly.

  Further, when the anchor bolt 10 having a large outer diameter is employed in order to increase the tensile loads P1, P2 generated on the anchor bolt 10 against the bending moment M, the corresponding nut member 12 is also enlarged. In addition, since it is necessary to increase the thickness of the column base metal 6, there is a problem in that the column base metal 6 is increased in size, weight, and cost.

Further, FIGS. 11 and 12 are referred to for explaining a second conventional column base hardware 22 and a column base structure 20 different from the first conventional column base metal 6 and the column base structure 2. FIG.
In the following description, the same parts as those of the first conventional column base metal 6 and the column base structure 2 are denoted by the same reference numerals, and the same parts as those of the first conventional column base metal 6 and the column base structure 2 are described. A duplicate description of the configuration is omitted except for a part thereof.

  As shown in FIG. 11, the second conventional column base structure 20 has another column base metal 22 instead of the column base metal 6 in the first conventional column base structure 2. This is different from the first conventional column base structure 2.

  As shown in FIG. 12, the column base metal 22 is formed in a plate shape having both a metal square front and back surface and a thickness, and penetrates in the thickness direction (perpendicular to the paper surface in the figure). A total of 12 bolt insertion holes 22a and 22b were formed. These bolt insertion holes 22a and 22b are formed to have substantially the same diameter, and one anchor bolt 10 is loosely inserted into each of them.

  Then, two bolt insertion holes 22a of the column base metal 22 are formed at positions adjacent to each side in an oblique direction at each of the four corners of the square shape of the column base metal 22.

  That is, the bolt insertion hole 22a of the column base metal 22 extends in the left-right direction in FIG. 12 and extends in the vertical direction in the figure from a virtual line X passing through the center position of the column base metal 22 in the vertical direction in FIG. From the imaginary line Y that is at a position separated by L1 and L3 and extends in the vertical direction in the figure and passes through the center position of the column base metal 22 in the horizontal direction in the figure, the length L3 in the horizontal direction in the figure The respective center positions are arranged at two positions separated by L1.

  The center position of the bolt insertion hole 22b of the column base metal 22 is arranged in the vicinity of the inside of the position of the central part in the length direction of each of the four square sides of the column base metal 22. That is, the bolt insertion hole 22b of the column base metal member 22 is, for example, on the side extending in the vertical direction in FIG. 12, at a position separated from the virtual line Y by the length L1 in the horizontal direction in the drawing and on the virtual line X. Each center position is arranged at each position.

  The second conventional column base structure 20 has the same problem as the first conventional column base structure 2.

  That is, with respect to the steel column 4 of the second conventional column base structure 20, for example, due to an earthquake or the like, around the rotation center O of the joint between the steel column 4 and the column base hardware 22 as shown in FIG. When a load that generates a large bending moment M that attempts to rotate the steel column 4 in the counterclockwise direction is applied to the anchor bolt 10 that fixes the right side portion of the column base hardware 22 in FIG. Tensile loads P1 and P3 are generated as reaction forces to prevent the right side portion of the column base metal member 22 from being lifted by the bending moment M, respectively.

  However, in the second conventional column base structure 20, in the left-right direction in FIG. 11, it looks like the same position as the rotation center O in the figure, and is inserted into the bolt insertion hole 22b in which the center position is arranged. The anchor bolt 10 does not generate a tensile load that opposes the bending moment M.

  For this reason, in the second conventional column base structure 20, there is an anchor bolt 10 that does not generate such a tensile load depending on the direction in which the bending moment M acts. There was a problem that the bending strength of the column base structure 20 as a whole with respect to the moment M was reduced accordingly.

  Accordingly, in view of the above problems, the present invention can improve the bending strength of the entire column base structure and can prevent the column base hardware from becoming larger, heavier and expensive. It is an object of the present invention to provide a column base structure using a slab.

In order to solve the above problems, the column base hardware according to the present invention is:
It is a column base metal that is formed in a plate shape having a square front and back both sides and thickness, and the lower end of the column member is joined to the surface thereof,
Three bolt insertion holes are formed in each of the four corners of the rectangular shape,
The three bolt insertion holes are characterized in that respective center positions are arranged such that the center of gravity of a triangle formed by line segments connecting the centers of the three bolts comes to a position corresponding to a corner of the column member. To do.

In addition, the column base hardware according to the present invention is:
The three bolt insertion holes are positioned closer to the center than the first bolt insertion holes formed at the four corners and the first bolt insertion holes at the two sides adjacent to the corners. It is the 2nd bolt insertion hole formed in this.

In addition, the column base hardware according to the present invention is:
A step recess having a height lower than the height from the front surface to the rear surface is formed on the rear surface side of the column base metal member on the outer side in the horizontal direction from the second bolt insertion hole.

In addition, the column base hardware according to the present invention is:
A straight line passing through the two centers of the second bolt insertion hole formed at two positions in the length direction of one side part, and a side part adjacent to the one side part in a direction perpendicular to the one side part. Insertion of the first bolt at a position shifted from the intersection of the straight line passing through the two centers of the second bolt insertion hole formed at two positions in the length direction of the first bolt. The center position of the hole is arranged.

In order to solve the above problems, the column base structure according to the present invention includes:
It is a column base structure provided with a column base hardware that is formed in a plate shape having a square front and back both sides and a thickness, and the lower end of the column member is joined to the surface thereof,
The column base hardware is
Three bolt insertion holes are formed in each of the four corners of the rectangular shape,
The three bolt insertion holes are characterized in that respective center positions are arranged such that the center of gravity of a triangle formed by line segments connecting the centers of the three bolts comes to a position corresponding to a corner of the column member. To do.

The column base structure according to the present invention is
The column base is provided above the foundation concrete, and an anchor bolt protruding upward from the foundation concrete is inserted into each of the three bolt insertion holes.

According to such a column base hardware of the present invention,
It is a column base metal that is formed in a plate shape having a square front and back both sides and thickness, and the lower end of the column member is joined to the surface thereof,
Three bolt insertion holes are formed in each of the four corners of the rectangular shape,
The three bolt insertion holes are arranged such that their center positions are arranged such that the center of gravity of a triangle formed by line segments connecting the centers of the three bolts comes to a position corresponding to the corner of the pillar member.
It is possible to improve the bending strength of the entire column base structure and to prevent the column base hardware from becoming large, heavy, and expensive.

Moreover, according to the column base structure of the present invention,
It is a column base structure provided with a column base hardware that is formed in a plate shape having a square front and back both sides and a thickness, and the lower end of the column member is joined to the surface thereof,
The column base hardware is
Three bolt insertion holes are formed in each of the four corners of the rectangular shape,
The three bolt insertion holes are arranged such that their center positions are arranged such that the center of gravity of a triangle formed by line segments connecting the centers of the three bolts comes to a position corresponding to the corner of the pillar member.
It is possible to improve the bending strength of the entire column base structure and to prevent the column base hardware from becoming large, heavy, and expensive.

It is a partial section side view showing column base structure 40 concerning one embodiment of the present invention. It is a top view of the column base metal object 42 in the column base structure 40 shown in FIG. FIG. 3 is a bottom view of the column base 42 shown in FIG. 2. It is a figure which expands and shows the upper right part in the figure of the column base metal object 42 shown in FIG. 2, Comprising: It is a partial enlarged top view for demonstrating each position of bolt insertion hole 42a, 42b. It is a conceptual side view for demonstrating the state where the tensile load T was added to the column base metal 42 in the column base structure 40 shown in FIG. It is a partial expanded sectional view which expands and shows the fastening part of the column base metal object 42 and the anchor bolt 10 in the column base structure 40 shown in FIG. It is a conceptual side view for demonstrating the state to which the bending moment M was added in the column base structure 40 shown in FIG. It is AA arrow sectional drawing of the column base structure 40 shown in FIG. 1 is a conceptual side view showing a first conventional column base structure 2. FIG. FIG. 10 is a top view of a first conventional column base metal 6 in the column base structure 2 shown in FIG. 9. It is a conceptual side view which shows the 2nd conventional column base structure. It is a top view of the column base metal object 22 in the column base structure 20 shown in FIG.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the column base metal object and column base structure using the same based on this invention is demonstrated concretely based on drawing.

  FIGS. 1-8 is a figure referred in order to demonstrate the column base metal 42 concerning one embodiment of this invention, and the column base structure 40 using the same.

  As shown in FIG. 1, the column base structure 40 according to the present embodiment includes a plate-shaped column base metal 42, and the column base metal 42 has a mortar 8 disposed above the foundation concrete 3. Is provided. In addition, in the column base metal 42, the lower end surface of the steel column 4 (column member) formed in a rectangular tube shape having a length in the vertical direction in the figure is joined to the upper surface 42c (surface) by welding. .

  And the upper end part of the anchor bolt 10 which penetrates the said mortar 8 from the basic concrete 3 and protrudes upwards thereof is inserted into bolt insertion holes 42 a and 42 b formed in the column base metal 42.

  By protruding the male screw portion formed at the upper end portion of the anchor bolt 10 protruding above the column base metal 42 through a through hole (not shown) of the washer 48 and screwing with the female screw portion of the nut member 12, The steel column 4 is erected and fixed on the foundation concrete 3 through a column base 42 and a mortar 8.

  A covering concrete 11 is formed on the foundation concrete 3. The covering concrete 11 has an upper surface at a position higher than the height upper end position of the upper end portion of the anchor bolt 10. The lower end portion of the steel column 4, the column base metal 42, the mortar 8, the upper end portion of the anchor bolt 10, Each member such as the nut member 12 is embedded therein.

  As shown in FIG. 2, the column base metal 42 is formed in a plate shape having both a metal square front and back surface and a thickness, and each of the four corners of the square has a square surface 42 h. Is formed.

  The column base 42 has bolt insertion holes 42a (first bolt insertion holes) and bolt insertion holes 42b (second bolt insertion holes) penetrating in the thickness direction (perpendicular to the paper surface in the figure). Twelve are formed in total, three at each corner. These bolt insertion holes 42a and 42b are formed to have substantially the same diameter, and one anchor bolt 10 is inserted loosely into each of them.

  One bolt insertion hole 42 a is formed in the vicinity of each of the four square corners of the column base 42.

  Further, the bolt insertion holes 42b are arranged at the center positions at both ends of the four square side portions of the column base metal 42 at positions closer to the center than the bolt insertion holes 42a at the corners.

  That is, as shown in FIG. 4, the bolt insertion hole 42a extends from a virtual line X (horizontal center line in the figure) extending in the left-right direction in the figure and passing through the center position of the column base metal 42 in the vertical direction in the figure. The imaginary line in the vertical direction in the figure is at a position separated by a length L5 shorter than the length L1 and extends in the vertical direction in the figure and passes through the center position of the column base metal 42 in the horizontal direction in the figure. Center positions are arranged at four positions (at the four corners) that are located at a distance L5 shorter than the length L1 in the left-right direction in the figure from Y (vertical center line in the figure). .

  And, for example, the bolt insertion hole 42b on the right side in FIG. 4 is at a position that is separated from the imaginary line Y by the length L1 in the right direction in the figure on the side portion of the column base metal 42 that extends in the vertical direction in FIG. The center position is arranged at a position away from the virtual line X by a length L4 in the vertical direction in the figure.

  In addition, each of the bolt insertion holes 42b has a center position disposed at substantially the same length from the virtual line X and the virtual line Y in each of the four sides.

  As shown in FIG. 4, the bolt insertion hole 42a formed at the corner of the column base 42 and the two bolt insertion holes 42b arranged on both sides of the bolt insertion hole 42a are centered on each other on the horizontal plane. Triangles are formed by line segments connecting the positions, and the center positions of the triangles are arranged such that the center of gravity G of the triangles is located at a position corresponding to the corner 4 a of the steel column 4.

  Similarly, the three anchor bolts 10 that pass through these bolt insertion holes 42a and the two bolt insertion holes 42b also form a triangle by a line segment that connects the center positions of each other on a horizontal plane, and the center of gravity G1 of this triangle is The respective center positions are arranged so as to come to positions corresponding to the corners 4 a of the steel column 4.

  Therefore, the center of gravity G1 of the three anchor bolts 10 inserted through the bolt insertion hole 42a and the two bolt insertion holes 42b is the same position as or similar to the center of gravity G of the bolt insertion hole 42a and the two bolt insertion holes 42b. Placed in position.

  The column base 42 transmits the force generated in the steel column 4 due to an earthquake or the like to the foundation concrete 3 via the anchor bolt 10. The thickness t of the column base 42 shown in FIG. 5 is set to a thickness that can withstand a predetermined bending stress.

  Here, when a bending moment M is applied to the column base structure 40 due to an earthquake or the like, as shown in FIG. 5, it occurs in the three anchor bolts 10 that are inserted through the bolt insertion holes 42a and the two bolt insertion holes 42b. When the resultant force of the tensile load is T, the tensile load T acts on the center of gravity G1 of the triangle of the three anchor bolts 10 in the column base 42.

  At this time, a bending moment M1 is generated at the height lower end position of the corner 4a of the steel column 4 of the column base 42. The bending moment M1 is proportional to the tensile load T and the distance L from the center of gravity G1 of the three anchor bolts 10 to the height lower end position of the corner 4a of the steel column 4.

  The thickness t of the column base metal 42 is set in consideration of the bending moment M1 applied to the column base metal 42.

  In the column base structure 40 according to the present embodiment, the center of gravity G1 on the horizontal plane of the three anchor bolts 10 passing through the bolt insertion hole 42a and the two bolt insertion holes 42b of the column base metal 42 is the steel column 4 The distance L from the center of gravity G1 of the anchor bolt 10 to the height lower end position of the corner 4a of the steel column 4 is remarkably shortened so as to approach substantially zero. Can do.

  And since the said bending moment M1 can be made remarkably small by making the distance L from the said gravity center G1 of the anchor bolt 10 to the height lower end position of the corner | angular part 4a of the steel column 4 remarkably small, column base metal 42 The thickness t can be reduced.

  For this reason, the column base structure 40 according to the present embodiment can reduce the thickness t of the column base hardware 42, thereby preventing an increase in size, weight, and cost of the column base hardware 42. .

  As shown in FIG. 3, the column base metal 42 has a stepped concave portion having a concave plane 42g that is recessed from the bottom surface 42d toward the back side of the paper surface in the figure at each of the four corners of the bottom surface 42d (back surface). Two step portions 42e are formed, and the height of the stepped recess 42e of the column base metal 42 is lower than the height from the bottom surface 42d to the top surface 42c.

  A boundary step surface 42f is formed at the step portion between the concave flat surface 42g and the bottom surface 42d of the step concave portion 42e, and the boundary step surface 42f is in contact with the inner peripheral surface of the bolt insertion hole 42b. Both end portions of the length are formed so as to extend to the side surface of the column base metal 42.

  For this reason, the step recess 42e is formed in a substantially triangular shape that extends outward from the bolt insertion hole 42b and opens to the side surface of the column base metal 42.

  In the column base structure 40 according to the present embodiment, the step recess 42e and the boundary step surface 42f are formed in the column base metal 42, and therefore acts on the horizontal section of the steel column 4 simultaneously with the bending moment M due to an earthquake or the like. Even if a horizontal force F (see FIG. 6) is applied to the column base metal 42 due to the shearing force, the column base metal 42 can be prevented from shifting in the horizontal direction.

  That is, as shown in FIG. 6, the mortar 8 filled between the bottom surface 42d of the column base metal 42 and the foundation concrete 3 is in close contact with the concave flat surface 42g and the boundary step surface 42f of the step concave portion 42e, and the bolt insertion hole. It fills between the concave flat surface 42g of the level | step-difference recessed part 42e, and the foundation concrete 3 so that it may contact | adhere also to a part of outer peripheral surface of the anchor bolt 10 which penetrates 42b.

  Therefore, when a shearing force acts on the steel column 4 due to an earthquake or the like and a horizontal force F directed to the left in the figure is applied to the column base metal 42 as shown in FIG. The force F operates such that the boundary step surface 42f of the column base metal 42 pushes each of several anchor bolts 10 corresponding to the horizontal force F on the downstream side in the direction of the horizontal force F through the mortar 8. Is transmitted to the several anchor bolts 10.

  And since some anchor bolts 10 exhibit resistance with respect to the horizontal force F, it is possible to prevent the column base metal 42 from being displaced in the horizontal direction with respect to the foundation concrete 3.

  Further, since the anchor bolt 10 receives the horizontal force F applied to the column base metal 42 and exhibits its resistance force, the horizontal force F is directly received only by the mortar 8 to prevent the mortar 8 from being broken. be able to.

  Further, as shown in FIGS. 3 and 6, the step recess 42 e of the column base metal 42 is formed in a shape that opens outward from the bolt insertion hole 42 b, so that the column base metal 42 and the foundation concrete 3 are formed. The mortar 8 can be easily filled between the two.

  As shown in FIGS. 1 and 8, in the column base structure 40 according to the present embodiment, the three anchor bolts 10 inserted into one bolt insertion hole 42 a and two bolt insertion holes 42 b are included in the foundation concrete 3. The lower ends of each are fixed to one fixing plate 44.

  As shown in FIG. 8, the fixing plate 44 is formed in an L-shaped plate shape. As shown in FIG. 1, the anchor plate 10 is loosely inserted into the through hole 44 a penetrating in the thickness direction of the fixing plate 44, and the nut member 46 is screwed to the anchor bolt 10 on the upper surface side and the lower surface side thereof. As a result, the fixing plate 44 is integrally fixed to the lower end portion of the anchor bolt 10 in the foundation concrete 3.

  As described above, in the column base structure 40 according to this embodiment, the three anchor bolts 10 are collectively fixed in the foundation concrete 3 by attaching one fixing plate 44 to the three anchor bolts 10. And can be easily attached.

  Such a column base structure 40 according to the present embodiment has a rotation center O of a joint portion with a column base metal 42 as shown in FIG. 7 with respect to the steel column 4 of the column base structure 40 due to, for example, an earthquake or the like. When a load that generates a large bending moment M is applied in the counterclockwise direction, the anchor bolt 10 that fixes the right portion of the column base metal 42 in the figure is fixed to the column base metal 42 by the bending moment M. Tensile loads P5 and P4 are generated as reaction forces to prevent the right side portion of the figure from rising.

  Here, in the conventional column base structure 2, the anchor bolt 10 inserted through the bolt insertion hole 6b and fixed at a position separated from the rotation center O of the steel column 4 in FIG. Although the load P2 is generated, in the column base structure 40 according to the present embodiment, the bolt insertion hole 42b located at a position separated from the rotation center O of the steel column 4 in FIG. The tensile load P4 generated in the anchor bolt 10 inserted and fixed is considerably larger than the tensile load P2 of the conventional column base structure 2 because the length L4 is longer than L2.

  Therefore, the bending strength of the column base structure 40 with respect to the bending moment M can be made considerably large as a whole as compared with the conventional column base structures 2 and 20.

  Moreover, as shown in FIGS. 2 and 4, in the column base structure 40 according to the present embodiment, the bolt insertion hole 42 a of the column base hardware 42 is 2 in the length direction of one side portion of the column base hardware 42. Bolt insertion holes formed at two positions in the length direction of the side that is adjacent to the one side at right angles to the straight line passing through the two central positions of the bolt insertion hole 42b formed at the position. From the position of the intersection with the straight line passing through the two central positions of 42b (position separated from the imaginary lines X and Y by the length L1 in FIG. 4) closer to the corner 4a of the steel column 4 (the center part of the column base hardware 42) The center position is arranged at a position shifted to the side.

  Thus, by arranging the center positions of the four bolt insertion holes 42a arranged at the four corners of the column base metal 42 at positions shifted closer to the corners 4a of the steel column 4 than the intersection points, Since the rigidity of the column base metal 42 becomes higher than that in the case where the bolt insertion hole 42a is disposed in the column insertion hole 42a, the thickness of the column base metal 42 can be reduced in consideration of an increase in the rigidity.

  Further, in the column base structure 40 according to the present embodiment, when the main reinforcing bars 14 extending in the left-right direction in FIG. 8 are arranged, bolts are provided at each side extending in the vertical direction of the column base hardware 42 in FIG. A space having a predetermined length is formed between the anchor bolts 10 and 10 inserted through the insertion holes 42b and 42b.

  For this reason, three main reinforcing bars 14 extending in the left-right direction in FIG. 8 can be collectively inserted in the interval, and one anchor bolt 10 is sandwiched between each of the three main reinforcing bars 14. Therefore, the reinforcing bar 14 is not obstructed by the anchor bolt 10, so that the reinforcing bar can be easily arranged.

  Further, even when the main reinforcing bars 14 (not shown) extending in the vertical direction in FIG. 8 are arranged, the arrangement work can be easily performed for the same reason.

  Further, in each side extending in the vertical direction of the column base metal member 42 in FIG. 8, there is a predetermined length interval between the anchor bolt 10 inserted into the bolt insertion hole 42a and the anchor bolt 10 inserted into the bolt insertion hole 42b. The main reinforcing bars 14 extending in the left-right direction in FIG. 8 can be inserted through these spaces one by one.

  Therefore, in each side extending in the vertical direction of the column base metal member 42 in FIG. 8, not only between the anchor bolts 10 and 10 inserted into the bolt insertion holes 42b and 42b, but also the anchor bolts 10 inserted into the bolt insertion holes 42a and By forming an interval through which the main rebar 14 can be inserted between the anchor bolts 10 inserted into the bolt insertion holes 42b, the main rebar 14 is interposed between the anchor bolts 10 on the back side of the drawing of the column base metal 42 in the drawing. Can arrange a lot.

  Further, when the main reinforcing bars 14 (not shown) extending in the vertical direction in FIG. 8 are arranged, for the same reason, the main reinforcing bars 14 are placed between the anchor bolts 10 on the back side of the drawing of the column base metal 42 in the drawing. A lot of reinforcement can be arranged.

  Therefore, as described above, according to the column base metal 42 and the column base structure 40 using the same according to the present embodiment, the bending strength of the entire column base structure 40 can be improved, and the column base An increase in size, weight, and cost of the hardware 42 can be prevented.

  In the column base structure 40 according to the above-described embodiment, the case where the column base hardware 42 has a square shape has been described. However, the column base structure 42 may have a square shape other than the square shape with different vertical and horizontal lengths.

  Further, in the column base structure 40 according to the embodiment, the bolt insertion holes 42a of the column base hardware 42 are bolts formed at two positions in the length direction of one side of the column base metal 42. A straight line passing through two central positions of the insertion hole 42b and two central positions of the bolt insertion holes 42b formed at two positions in the length direction of the side adjacent to the one side in the direction perpendicular to the one side. Although the center position is arranged at a position shifted from the position of the intersection with the straight line toward the corner 4a of the steel column 4, even if the center position of the bolt insertion hole 42a is arranged at the position of the intersection Good.

  Further, in the column base metal 42 according to the above embodiment, the step recesses 42e are formed at the four corners of the bottom surface 42d, but the step recesses are formed at any corner of the bottom surface 42d. You may apply this invention to the column base metal which does not provide 42e.

  Further, in the column base metal 42 according to the above-described embodiment, the fixing plate 44 is formed of an L-shaped plate material. However, all of the twelve anchor bolts 10 are formed using a single B-shaped fixing plate. May be fixed to the one fixing plate, or one fixing plate may be fixed to one anchor bolt 10 respectively.

  In the column base structure 40 according to the embodiment, as shown in FIG. 8, the three main reinforcing bars 14 are arranged between the anchor bolts 10 and 10 inserted into the two bolt insertion holes 42b on one side. Although the case has been described, if possible, four or more main reinforcing bars 14 may be arranged between the anchor bolts 10 and 10.

  If possible, two or more main reinforcing bars 14 may be disposed between the anchor bolt 10 inserted into the bolt insertion hole 42a on one side and the anchor bolt 10 inserted through the bolt insertion hole 42b. .

  In the column base structure 40 according to the above embodiment, the steel column 4 whose lower end surface is joined to the upper surface 42c of the column base metal 42 by welding is formed in a square tube shape, but in this shape. For example, it may be formed in a cylindrical shape.

  When the shape of the steel column 4 is changed to a cylindrical shape, a portion of the circular outer peripheral surface of the steel column 4 at the shortest distance from the center position of the bolt insertion hole 42a in the horizontal cross section of the column base structure 40 Can be regarded as corresponding to the corner 4a in the present invention.

  Further, in the column base structure 40 according to the embodiment, the covered concrete 11 is formed on the foundation concrete 3, but the present invention is applied to a column base structure in which the cover concrete 11 is not formed on the foundation concrete 3. May be.

  When the covering concrete 11 is not formed, the female threaded portions of the two nut members 12 are connected to the male threaded portion formed at the upper end portion of the anchor bolt 10 so that the screw fastening of the anchor bolt 10 and the nut member 12 is not loosened. Is preferably screwed (double nut clamped).

2 Column base structure 3 Foundation concrete 4 Steel column 4a Corner 6 Column base 6a, 6b Bolt insertion hole 8 Mortar 10 Anchor bolt 11 Covering concrete 12 Nut member 14 Main reinforcement 20 Column base 22 Column base 22a, 22b Bolt insertion Hole 40 Column base structure 42 Column base hardware 42a, 42b Bolt insertion hole 42c Top surface 42d Bottom surface 42e Step recess 42f Boundary step surface 42g Concave plane 42h Square surface 44 Fixing plate 44a Through hole 46 Nut member 48 Washer F Horizontal force G, G1 Center of gravity L Distance L1, L2, L3, L4, L5 Length M, M1 Bending moment O Center of rotation P1, P2, P3, P4, P5 Tensile load T Tensile load t Thickness X, Y Virtual line

Claims (6)

It is a column base metal that is formed in a plate shape having a square front and back both sides and thickness, and the lower end of the column member is joined to the surface thereof,
Three bolt insertion holes are formed in each of the four corners of the rectangular shape,
The three bolt insertion holes are characterized in that their center positions are arranged such that the center of gravity of a triangle formed by line segments connecting the centers of the three bolts comes to a position corresponding to a corner of the column member. Column base hardware to do.   The three bolt insertion holes are positioned closer to the center than the first bolt insertion holes formed at the four corners and the first bolt insertion holes at the two sides adjacent to the corners. 2. The column base hardware according to claim 1, wherein the second column insertion hole is formed in the first bolt insertion hole.   3. The column base metal according to claim 2, wherein a step recess having a height lower than the height from the front surface to the back surface is formed on the back side of the column base metal on the outer side in the horizontal direction from the second bolt insertion hole. A straight line passing through the two centers of the second bolt insertion hole formed at two positions in the length direction of one side part, and a side part adjacent to the one side part in a direction perpendicular to the one side part. Insertion of the first bolt at a position shifted from the intersection of the straight line passing through the two centers of the second bolt insertion hole formed at two positions in the length direction of the first bolt. The column base metal according to claim 2 or 3, wherein a center position of the hole is arranged. It is a column base structure provided with a column base hardware that is formed in a plate shape having a square front and back both sides and a thickness, and the lower end of the column member is joined to the surface thereof,
The column base hardware is
Three bolt insertion holes are formed in each of the four corners of the rectangular shape,
The three bolt insertion holes are characterized in that their center positions are arranged such that the center of gravity of a triangle formed by line segments connecting the centers of the three bolts comes to a position corresponding to a corner of the column member. Column base structure.   6. The column according to claim 5, wherein the column base metal is provided above the foundation concrete, and an anchor bolt protruding upward from the foundation concrete is inserted into each of the three bolt insertion holes. Leg structure.

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