JP2009275390A - Base plate for column base, and column base structure using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base plate for an exposed-type steel column base, which can adapt even to an increase in the size of a steel column by enhancing flexural rigidity without increasing the plate thickness of a base plate body portion, and a column base structure using the base plate. <P>SOLUTION: In this flat plate-like base plate 1, the base plate body portion 2 is fixed to a lower end of the steel column 4 on a top surface side; anchor bolts 6 protruding from foundation concrete 5 are inserted through a plurality of bolt insertion holes which are provided in the peripheral portion of the base plate body portion 2, and tightened with nuts 7 from above, respectively, so that the steel column 4 can be fixed to the foundation concrete 5. A stiffening portion 3 is composed of a columnar portion 3a in almost the same cross-sectional shape, which is in a position corresponding to a fixing portion of the steel column 4, and outside and inside plate-like portions 3b and 3c, which is in a crossing state on the inside and outside of the sidewall surface of the columnar portion 3a. The stiffening portion 3 is provided on the undersurface side of the base plate body portion 2, so that the peripheral portion of the base plate body portion 2, in which the anchor bolt 6 is arranged, can be effectively reinforced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is fixed to the lower end portion of a steel column as an intermediate material for fixing the steel column to the foundation concrete in an exposed column base structure such as a steel frame, a steel reinforced concrete structure, a filled steel pipe concrete structure, etc. The present invention relates to a column base plate and a column base structure using the base plate.

  The column base plays an important role in transmitting axial force, shearing force and bending moment acting on the lower end of the column material to the foundation concrete. In the exposed steel column base, the compressive axial force is stress-transmitted from the steel column through the base plate to the foundation concrete, and the tensile axial force is transmitted from the steel column through the base plate to the anchor bolt and the foundation concrete. The bending moment transmits the compressive force from the steel column through the base plate on the one hand to the foundation concrete and, on the other hand, the tensile force from the anchor bolt to the foundation concrete. Further, transmission of shear force is generally classified into the following three types.

First, there is a method of transmitting by friction between the lower surface of the base plate and the surface of the foundation concrete. In this case, the shear strength depends on the column axial force, but the tensile strength of the anchor bolt does not decrease. Next, a washer having a hole substantially the same diameter as the anchor bolt diameter is welded to the upper surface of the base plate and transmitted from the base plate to the anchor bolt. In this method, the shear force does not depend on the column axial force, but the tensile strength of the anchor bolt is reduced. Furthermore, there is a method in which a shear key is welded to the lower surface of the base plate and transmitted from the steel column to the foundation concrete via the base plate (shear key). In this case, the shearing force does not depend on the column axial force, and the tensile strength of the anchor bolt does not decrease. Thus, the base plate is an important member for transmitting various forces acting from the steel column to the foundation concrete.

By the way, for a steel column with a relatively small column size, a base plate in which a standard rolled steel plate is cut into a rectangular plate of an appropriate size and a required number of bolt insertion holes are provided in the peripheral portion is easy to manufacture. For reasons such as this, it surpasses that of cast steel. On the other hand, since the anchor bolt is also increased in diameter as the column size of the steel column is increased, a base plate applied to a large-sized steel column is required to have high bending rigidity and yield strength. In the base plate made of rolled steel plate, the increase in the plate size will correspond to the increase in the column size, but the rolled steel plate for the base plate whose plate thickness exceeds 100 mm is out of specification at the present time, Is not supplied. For this reason, even if productivity is sacrificed, it is the actual situation that it is unavoidable that it is made of cast steel. Note that even if an extremely thick rolled steel sheet can be supplied, some problems are concerned when this is actually used. One of them is that the difference between the thickness of the steel column to be applied and the thickness of the base plate is too wide. This point affects weldability and can cause serious problems in the joint strength between the two. Under such circumstances, methods for dealing with an increase in the column size without increasing the thickness of the base plate have been studied. Specifically, a base plate in which a plurality of ribs are arranged on the upper surface side of a rectangular steel plate serving as a main body (Patent Document 1), and a two-stage base plate in which a plurality of ribs are arranged between two steel sheets (Patent Document 2) ), And the base plate (Patent Document 3), which has been integrally provided with a few millimeters of protrusions such as weld beads on the lower surface of the steel plate, has been proposed so far, both of which add rib-shaped stiffening means to the main body of the base plate It is what.
Japanese Utility Model Publication No. 61-33761 (see FIG. 2) JP 11-159007 A (see FIG. 6) Japanese Patent No. 3391438 (see FIG. 1)

In the base plate described in Patent Document 1, a nut screwed into an upper end portion of an anchor bolt protruding from a bolt insertion hole of the base plate main body portion is formed from both sides by a plurality of ribs integrally standing on the upper surface of the base plate main body portion. Since it is the structure enclosed, the operation space which does not prevent the rotation operation | movement of a spanner is required between the adjacent ribs, when tightening | tightening a nut. However, when multiple anchor bolts are arranged in the middle part of each side, such as a large base plate with a large number of anchor bolts, the interval between the ribs on those sides is set. It becomes difficult to secure enough. Therefore, it is conceivable to reduce the thickness of individual ribs or simply increase the total width of the base plate. However, both methods lead to a decrease in the bending rigidity of the base plate. Is not a good idea to increase the size of the base plate.

On the other hand, in the base plate described in Patent Document 2, since there is no rib on the upper surface side, there is no need to consider the operation space of the tightening tool, which was a problem of the former base plate, and the box shape allows the rib to be There is an advantage that a large bending rigidity and proof stress can be obtained as compared with the case where the stiffening is performed alone. In this case, since each member is integrated by welding work, the interval between the upper and lower two steel plates and the interval between the plurality of ribs arranged between them are important requirements in terms of productivity. It becomes. If productivity is prioritized and the gap between ribs is large, the stiffening effect for bending is reduced as in the former, so the thickness of the upper steel plate needs to be increased, and eventually it is large. The structure is not suitable for a size base plate. Furthermore, since the welding amount is increased as compared with the former base plate and the welding work is performed in a narrow space, there are problems such as poor workability.

Next, the base plate described in Patent Document 3 is intended to improve rigidity by providing a plurality of ridges on the lower surface, but even from the ratio between the plate thickness of the base plate body and the height of the ridges. The effect is clearly secondary. That is, the original purpose of the ridge is to prevent relative displacement between the base plate and the mortar packed bed when a large lateral force (shearing force) acts on the column base due to an earthquake or the like. Is for. Since the main purpose of the ridges in this case is to increase the friction coefficient between the bottom surface of the base plate and the mortar packed layer, a pattern in which a compressive force is applied to the mortar packed layer such as a radial shape as the arrangement form. Selected preferentially. In this prior art, the arrangement form from the viewpoint of improving the bending rigidity of the base plate and the shape of the ridge are not particularly taken into consideration. Accordingly, there is a lot of room for examination as to whether or not such ridges can be directly applied to a large-sized base plate.

  In view of these problems of the prior art, the present inventors have intensively studied the stiffening means to be added to the base plate body, and have arrived at the present invention. That is, in the present invention, an effective arrangement form of the stiffening member is found, thereby increasing the bending rigidity without increasing the thickness of the base plate main body, and the column base plate that can cope with the enlargement of the size of the steel column. The purpose is to provide a column base structure using this.

  In order to solve the above-mentioned problem, in the invention according to claim 1 of the present application, the base plate main body is fixed to the lower end portion of the steel column on the upper surface side, and a plurality of bolt insertion holes provided in the peripheral portion are provided with basic concrete. In a base plate for a column base for inserting a plurality of anchor bolts protruding from the surface and fixing the steel column to the foundation concrete by tightening a nut from above, the base plate main body is formed in a flat plate shape, and the base plate main body A columnar portion having substantially the same cross-sectional shape at a position corresponding to the fixing portion of the steel column on the lower surface side of the portion, and a side wall surface positioned at least on the peripheral side of the base plate main body in a state of intersecting the side wall surface of the columnar portion The technical means of providing a stiffening portion composed of a plurality of outer plate-like portions standing at intervals along each other is adopted.

  Further, with respect to the stiffening portion in the above-described configuration, it is possible to add an inner plate-like portion at a position opposed to at least a part of the outer plate-like portion sandwiching the side wall of the columnar portion (Claim 2). It may be cast integrally with the base plate body (claim 3). In addition, when the thing of a closed cross section is employ | adopted for the columnar part of a stiffening part, it is preferable to provide the flow path of fillers, such as mortar, in the side wall (Claim 4), and the board thickness of a baseplate main-body part is anchored. It is also possible to make it smaller than the outer diameter of the bolt (Claim 5).

  Further, in the invention according to claim 6 of the present application, the base plate main body is fixed to the lower end of the steel column formed in the closed cross section on the upper surface side, and a plurality of bolt insertion holes provided in the peripheral portion are provided with a foundation. In a column base structure in which a plurality of anchor bolts protruding from the concrete surface are inserted and the steel column is fixed to the foundation concrete by tightening a nut from above, the base plate body is formed in a flat plate shape, and the base plate body A columnar portion having substantially the same cross-sectional shape at a position corresponding to the fixing portion of the steel column on the lower surface side of the portion, and a side wall surface positioned at least on the peripheral side of the base plate main body in a state of intersecting the side wall surface of the columnar portion A stiffening portion composed of a plurality of outer plate-like portions standing at intervals from each other is provided, and a filler such as mortar is provided in at least the columnar portion of the stiffening portion. Adopted the technology means that Hama. A plurality of through holes may be formed in the side wall of the columnar portion of the stiffening portion, and reinforcing bars may be inserted between the side walls at the opposing positions via the through holes.

In the present invention, the following effects can be obtained by adopting the above configuration.
(1) By filling at least the columnar portion of the stiffening portion provided on the lower surface side of the base plate main body portion with a filler such as mortar, deformation to the inside of the columnar portion is eliminated, and the solid columnar portion is integrated with the solid columnar portion. The plurality of outer plate-like portions arranged in an intersecting state on the outside effectively reinforces the peripheral portion of the base plate main body portion. Due to the presence of such a stiffening portion, the bending rigidity of the base plate main body portion is improved, the plate thickness of the base plate main body portion can be reduced, and an economical column base structure can be realized.
(2) Since the stiffening part is located on the lower surface side of the base plate main body part, it becomes possible to provide the outer plate-like part of the stiffening part near the anchor bolt without considering any nut tightening operation. A base plate that makes the most of its reinforcing effect can be obtained.
(3) If the stiffening portion is provided with an inner plate-like portion on the opposite side of the columnar portion so as to face at least a part of the outer plate-like portion, the reinforcing effect is further enhanced. The plate thickness of the main body can be further reduced.
(4) If the columnar part of the stiffening part has a closed cross section and a flow path of a filler such as mortar is provided on the side wall, the filling property of the mortar or the like in the columnar part is improved when the column base structure is formed. The reinforcing effect by the stiffening portion can be made more reliable.
(5) If a column base structure is formed in which a plurality of through holes are formed in the side wall of the columnar portion of the stiffening portion, and a reinforcing bar is inserted between the side walls at opposite positions via the through hole, the shear strength by the stiffening portion It is possible to further improve the tension performance of the anchor bolt irrespective of the axial force of the steel column.

The column base plate according to the present invention has a technical feature in that an effective shape and arrangement form have been found for a stiffening means such as a rib, which has been conventionally studied in order to improve bending rigidity and yield strength. is there. Thereby, application to a steel column with a large column size is possible while suppressing the plate thickness of the base plate body. The target steel frame column is not limited to a square steel pipe, but may be a round steel pipe or an H-shaped steel. In any case, the overall shape of the base plate body is preferably substantially rectangular in plan view. The material of the base plate body is not limited to a rolled steel plate, and cast steel may be used. In this case, it is possible to cast the stiffening part integrally with the base plate body part. On the other hand, when the rolled steel plate is applied to the base plate main body, the stiffening portion may be integrated with the base plate main body by welding by combining appropriately sized steel plates, and the forming method and procedure thereof are not particularly limited. In the stiffening portion, the crossing state of the outer plate portion with respect to the side wall surface outside the columnar portion does not necessarily have to be orthogonal, and can be brought into contact with each other at an angle. In the present invention, due to the presence of the stiffening portion, the thickness of the base plate main body can be made smaller than the outer diameter of the thick anchor bolt used in the column base of the steel column having a large column size. Moreover, if the height of the stiffening portion is appropriately secured, a base plate body portion having a thickness not so large can be used. The positions of the bolt insertion holes through which the anchor bolts are inserted may be at least at the four corners of the base plate body. For example, there are various types depending on the number, such as those provided in plural at each corner, those provided at the sides between the corners, or those equally arranged along the four sides. Of course, various modifications can be made within the technical concept of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 to 4 show a first embodiment of a column base plate according to the present invention, and FIGS. 1 and 2 are a bottom view and a perspective view thereof, respectively. The illustrated base plate 1 is intended for a steel column made of a square steel pipe, and comprises a square base plate main body portion 2 made of a rolled steel plate and a rib-shaped stiffening portion 3 welded to the lower surface thereof.

  The stiffening portion 3 is composed of a collection of small pieces of rolled steel sheet that is thinner than the thickness of the base plate body portion 2. In the center of the base plate main body 2, a rectangular frame-shaped columnar portion 3a is provided, and an outer plate-shaped portion 3b having substantially the same height in the shape of one corner of the rectangle being obliquely cut is provided on the side wall surface. It welds in the state which contact | abutted at right angle 4 pieces on each surface along the outer side. Furthermore, the inner side plate-like part 3c is welded to the opposite side of the side wall surface of the columnar part 3a so as to oppose two outer side plate-like parts 3b located in the middle of each side of the base plate main body part 2. In this embodiment, 16 bolt insertion holes 2a are opened between the adjacent outer plate-like portions 3b and 3b. In addition, the dimension of the columnar part 3a is substantially the same as the diameter of the steel column fixed to the upper surface side, and it is convenient to use a steel column of the same size by cutting it to an appropriate length. The cross-sectional shapes of both need not necessarily be the same shape. That is, it is possible to apply an assembled box-shaped cross-sectional columnar shape formed by welding four steel plates to the columnar portion 3a with respect to a steel column made of a square steel pipe as in the embodiment, and vice versa. A combination may be used, and the point is that there is no problem as long as the shape is substantially the same.

  FIG. 3 and FIG. 4 are an explanatory diagram showing an assembling procedure of the column base plate 1 according to the present invention and a perspective view showing a state of being fixed to the steel column. As shown in FIG. 3, the columnar portion 3 a is first welded to the center of the lower surface of the base plate main body portion 2. Next, the stiffened portion 3 is formed by welding the outer plate-like portion 3b and the inner plate-like portion 3c to the side surface of the columnar portion 3a and the base plate main body portion 2 at predetermined positions. Then, the lower end part of the steel column 4 which consists of a square steel pipe is welded to the upper surface of the baseplate main-body part 2 corresponding to the welding position of the columnar part 3a. Instead of the method of sequentially welding each member to the base plate main body 2 as described above, the columnar portion 3a, the outer plate-shaped portion 3b, and the inner plate-shaped portion 3c are welded to each other in advance. The stiffening portion 3 can be formed and welded to the base plate main body portion 2, and the assembling procedure is not particularly limited. Further, the stiffening portion 3 having the same shape may be formed of cast steel instead of the aggregate of small pieces of steel plates and welded to the base plate main body portion 2.

  FIG. 5 is an explanatory diagram of a load bearing mechanism when a bending moment is applied in the column base structure using the column base plate 1 according to the present invention. In addition, about a construction method, the box-shaped recessed part which can accommodate the baseplate 1 in the surface part of the foundation concrete 5 is formed previously. In this recess, an upper end portion of an anchor bolt 6 having a fixing plate (not shown) attached to the lower end portion protrudes by a predetermined length. And the upper end part of each anchor bolt 6 is inserted in the bolt insertion hole 2a of the base plate 1 fixed to the lower end of the steel column 4, and the stiffening part is connected to the bottom face of the concave portion of the foundation concrete 5 through an appropriate spacer or the like. After placing with a gap below 3, the nut 7 screwed into the anchor bolt 6 is tightened, and non-shrink grout mortar is injected into the space on the lower surface of the base plate body 2 by appropriate means. The non-shrink grout mortar is filled without a gap between the inside of the columnar portion 3a of the stiffening portion 3 and the outer outer plate-like portion 3b. As a result, the steel column 4 is fixed to the foundation concrete 5 via the base plate 1. Even if the steel column 4 or the like is placed as it is without providing a concave portion on the surface portion of the foundation concrete 5, the entire circumference of the side surface of the base plate 1 is surrounded by an appropriate formwork, and in this state, non-shrink grout mortar is filled. Good.

  Next, the mechanism of load resistance will be described. As shown in FIG. 5 (a), the tensile stress from the steel column 4 based on the bending moment M is transmitted to the columnar portion 3a of the stiffening portion 3 via the base plate 1, and further from this columnar portion 3a to the base plate main body. Stress is transmitted to the outer plate-like portion 3b arranged near the anchor bolt 6 along the periphery of the portion 2 and the inner plate-like portion 3c at the opposite position, and finally, via the base plate 1 It is transmitted to the anchor bolt 6. As shown in FIG. 5 (b), since the columnar portion 3a is prevented from being deformed inward by the non-shrinkable grout mortar filled therein, the columnar portion 3a is substantially orthogonal to the outside on the outside. The outer plate-like portion 3b arranged in a state effectively supports (stiffens) the peripheral portion of the base plate main body 2 and does not bend and deform.

  6 and 7 are a bottom view of a column base plate according to a second embodiment of the present invention and a front view of a state where a steel column is fixed, respectively. Note that the description of the same parts as in the above embodiment is omitted. The column base 8 shown in the figure is for a steel column whose base plate body 9 is made of a rolled steel plate having a square shape and whose closed cross section is a substantially rectangular shape, such as a square steel pipe, as in the first embodiment. . The stiffening portion 10 in this case includes a columnar portion 10a obtained by cutting a square steel pipe into a predetermined length, two types of outer plate-like portions 10b and 10c, and an inner plate-like portion 10d. That is, the two outer plate-like portions 10b and 10b arranged on both sides of each bolt insertion hole 9a located at the four corners of the base plate main body portion 9 are substantially the same as the side wall surfaces avoiding the corners of the columnar portion 10a. They are welded in a state of being substantially parallel to each other at an angle of 45 degrees. The inner plate-like portion 10d is located at an intermediate portion on each side of the base plate main body portion 9, and is opposed to the two outer plate-like portions 10c that are welded in an orthogonal state to the outer side wall surface of the columnar portion 10a. It is welded in an orthogonal state to the inner side wall surface.

  FIGS. 8 and 9 are a bottom view of a column base plate according to a third embodiment of the present invention and a front view of a state where a steel column is fixed, respectively. The illustrated column base 11 is a modification of the second embodiment, and two bolt insertion holes 12a and 12a are provided at the four corners of a square base plate main body 12 made of rolled steel plate, respectively. Two pieces are arranged at each corner so as to be parallel to a tangent of 45 degrees drawn at 12 corners. Along with this, the positions of some outer plate-like portions in the stiffening portion 13 are changed. That is, one outer plate-like portion 13b is disposed between the bolt insertion holes 12a and 12a located at the four corners. The outer plate-like portion 13b is joined to the corner portion of the central columnar portion 13a so as to face the center thereof, and the other outer plate-like portions 13c are three on each side of the base plate body portion 12, It joins in the substantially orthogonal state with respect to the side wall surface of the outer side of the columnar part 13a. The inner plate-like portion 13d is disposed on the inner side of the columnar portion 13a so as to oppose only the outer plate-like portion 13c adjacent to the outer plate-like portion 13b at the four corners.

  FIG. 10 is a perspective view seen from the lower surface side of the column base plate according to the fourth embodiment of the present invention. The illustrated column base 14 has the same shape of the base plate main body 15 and the position of the bolt insertion hole 15a as in the first embodiment, but the shape of the stiffening portion 16 is different. In other words, the square columnar portion 16a includes an outer plate located between the adjacent outer plate-like portions 16b and 16b located in the middle of each side of the base plate main body portion 15 and between the outer outer plate-like portion 16b and the end portion. An oval through-hole 16d is formed in each side wall between the cylindrical portions 16c. In this case, the inner plate-like portion 16e is disposed to face the two outer plate-like portions 16b and 16b located in the middle. Further, an oblong through hole 16d is formed in the rectangular outer plate portion 16c itself that is closest to the bolt insertion hole 15a at the four corners of the base plate body portion 15. In this case, since the through holes 16d serve as a flow path of the non-shrink grout mortar, there is an effect of improving the filling property to the lower surface of the base plate main body portion 15. The two outer plate-like parts 16b located in the middle part of each side of the base plate main body part 15 do not have through holes 16d, but the corners on the non-joining part side close to the peripheral side of the base plate main body part 15 are provided. By largely notching, the flowability of the non-shrink grout mortar can be ensured.

  FIG. 11 and FIG. 12 are a sectional view of a column base structure using the column base plate 14 according to the fourth embodiment and a bottom view showing an arrangement state of reinforcing reinforcing bars. In this case, the through-hole 16d opened in the columnar portion 16a of the stiffening portion 16 is used. This is an example in which an L-shaped reinforcing bar 17 is inserted into a through-hole 16d at the opposite position among the four side walls of the columnar portion 16a, and is an effective method for further increasing the shear strength of the column base. .

  13 and 14 are a perspective view seen from the lower surface side of a column base plate according to a fifth embodiment of the present invention and a cross-sectional view of a column base structure using the same. The illustrated column base plate 18 is the same as the column base plate according to the fourth embodiment, except that a large through hole 19a is provided in the central portion of the base plate body 19 and the stiffening portion 20 is the same. When such a base plate 18 is used, as shown in FIG. 14, the reinforcing steel bar 21 rising from the foundation concrete 5 is received inside the steel column 4 through the central through hole 19a, and the lower end portion thereof is received. By burying with the filled concrete 22, the proof strength of the column base can be further improved.

  FIG. 15: is the perspective view seen from the lower surface side of the base plate for column bases concerning 6th Example of this invention. The illustrated column base plate 23 is for a steel column made of a circular steel pipe and is intended for a type with eight anchor bolts. The base plate main body 24 is made of a rolled steel plate appropriately sized in the same manner as in the above embodiments, and eight bolt insertion holes 24a are arranged in the vicinity of each corner two by two as in the third embodiment. Has been. The columnar portion 25 a of the stiffening portion 25 is obtained by cutting a circular steel pipe having substantially the same size as that of the steel column 26 into a predetermined length, and is provided concentrically with the steel column 26. To this columnar portion 25a, three 12 outer plate-like portions 25b are joined together in a radial manner so as to sandwich the two bolt insertion holes 24a, 24a at each corner of the base plate body portion 24. ing. One inner plate-like portion 25c is provided at a position facing the outer plate-like portion 25b disposed between the two bolt insertion holes 24a, 24a at each corner.

  FIG. 16: is the perspective view seen from the lower surface side of the base plate for column bases concerning 7th Example of this invention. The illustrated column base 27 for a column base is for a steel column made of H-shaped steel, and is intended for a type with four anchor bolts. The base plate body 28 is made of a rectangular rolled steel plate. On its lower surface, stiffening consisting of a columnar portion 29a, six outer plate-like portions 29b and four inner plate-like portions 29c obtained by cutting an H-shaped steel of approximately the same size as the steel column 30 into a predetermined length. A portion 29 is provided. The six outer plate-like portions 29b are joined three by three on the short side of the base plate main body portion 28 at intervals from each other on the outer sides of both flange surfaces of the columnar portion 29a having an H-shaped cross section. The bolt insertion hole 28a is opened between the outer plate portions 29b. The four inner plate portions 29c are provided at positions facing the outer plate portions 29b located on both long sides of the base plate main body portion 28. The steel column 30 is fixed to a position opposite to the columnar portion 29 a on the opposite side of the base plate main body portion 28.

  In each of the above embodiments, a rolled steel plate is used as the base plate body, and a stiffening portion made of an aggregate of small pieces of steel is joined and integrated. However, both are integrally formed by casting. Alternatively, either one may be made of cast steel and the other may be made of steel plate, and both may be joined and integrated. Further, in any of the embodiments, the inner plate-like portion is provided, but this is omitted, and the stiffening effect can be sufficiently obtained with only the columnar portion and the outer plate-like portion.

It is a bottom view of the column base plate according to the first embodiment of the present invention. It is a perspective view of the base plate for column bases shown in FIG. It is explanatory drawing which showed the assembly procedure of the base plate for column bases shown in FIG. It is the perspective view which showed the state after the assembly of FIG. It is explanatory drawing which showed the load-bearing mechanism when a bending moment is loaded on the column base structure using the base plate for column bases concerning this invention. It is a bottom view of the column base plate according to the second embodiment of the present invention. It is a front view of the state which fixed the steel column to the base plate for column bases shown in FIG. It is a bottom view of the column base plate according to the third embodiment of the present invention. It is a front view of the state which fixed the steel column to the base plate for column bases shown in FIG. It is the perspective view seen from the lower surface side of the base plate for column bases which concerns on 4th Example of this invention. It is sectional drawing of the column base structure using the base plate for column bases shown in FIG. It is the bottom view which showed the reinforcement arrangement | positioning state of the reinforcing steel bar in FIG. It is the perspective view seen from the lower surface side of the base plate for column bases concerning 5th Example of this invention. It is sectional drawing of the column base structure using the base plate for column bases shown in FIG. It is the perspective view seen from the lower surface side of the base plate for column bases concerning 6th Example of this invention. It is the perspective view seen from the lower surface side of the base plate for column bases concerning 7th Example of this invention.

Explanation of symbols

1,8,11,14,18,23,27 ... Base plate for column base 2,9,12,15,19,24,28 ... Base plate main body 3,10,13,16,20,25,29 ... Supplement Rigid part 4, 26, 30 ... Steel column 5 ... Foundation concrete 6 ... Anchor bolt 7 ... Nut 17, 21 ... Reinforcing bar 22 ... Concrete,
2a, 9a, 12a, 15a, 24a, 28a ... bolt insertion holes 3a, 10a, 13a, 16a, 25a, 29a ... columnar portions 3b, 10b, 10c, 13b, 13c, 16b, 16c, 25b, 29b ... outer plate shape Portions 3c, 10d, 13d, 16e, 25c, 29c ... inner plate portions 16d, 19a ... through holes

Claims (7)

The base plate main body is fixed to the lower end of the steel column on the upper surface side, and multiple anchor bolts protruding from the foundation concrete surface are inserted into the multiple bolt insertion holes provided in the peripheral portion, and the nut from above In the base plate for the column base for fixing the steel column to the foundation concrete by tightening, the base plate main body portion is formed in a flat plate shape, and the lower surface side of the base plate main body portion has a position corresponding to the fixing portion of the steel column. And a plurality of outer sides standing at intervals along the side wall surface located at least on the peripheral side of the base plate main body in a state of intersecting the side wall surface of the columnar part. A base plate for a column base having a stiffening portion made of a plate-like portion. 2. The column base plate according to claim 1, wherein the stiffening portion includes an inner plate-like portion at a position opposed to at least a part of the outer plate-like portion sandwiching the side wall of the columnar portion. opposite side The base plate for a column base according to claim 1 or 2, wherein the stiffening portion is integrally cast with the base plate main body portion. The columnar base plate according to any one of claims 1 to 3, wherein the columnar portion of the stiffening portion has a closed cross-section, and a flow path of a filler such as mortar is provided on a side wall thereof. The base plate for a column base according to any one of claims 1 to 4, wherein a thickness of the base plate main body is smaller than an outer diameter of the anchor bolt.   The base plate main body is fixed to the lower end of the steel column formed in a closed cross section on the upper surface side, and multiple anchor bolts protruding from the foundation concrete surface are inserted into the multiple bolt insertion holes provided in the peripheral part. In the column base structure in which the steel column is fixed to the basic concrete by tightening the nut from above, the base plate main body is formed in a flat plate shape, and the steel column is fixed to the lower surface side of the base plate main body. A columnar section having substantially the same cross-sectional shape at a position corresponding to the section, and standing at a distance from each other along the side wall surface positioned at least on the peripheral side of the base plate body section in a state of intersecting the side wall surface of the columnar section A stiffening portion comprising a plurality of outer plate-shaped portions is provided, and at least a columnar portion of the stiffening portion is filled with a filler such as mortar. Pedestal structure.   The column base according to claim 6, wherein a plurality of through holes are formed in a side wall of the columnar portion of the stiffening portion, and a reinforcing bar is inserted between the side walls at opposite positions via the through hole. Construction.

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