JP2019044401A - Column leg joining structure - Google Patents

Abstract

To enable absorption of energy of vibration or the like through plastic deformation of an anchor bolt and replacement of the anchor bolt in a structure where a column having a base plate fixed thereto is joined to a foundation made of concrete.SOLUTION: An anchor member 4 for coupling a base plate 3 to a foundation 2 has: a rod-shaped lower anchor 41 the lower part of which is buried in the concrete 21 of the foundation; a buried nut 42 that is engaged with a male screw formed at the lower end of the lower anchor 41; a fixing plate 43 that is locked to the buried nut 42; an anchor bolt 44 that is joined to the upper part of the lower anchor 41 and coupled to the base plate 3; and a nut 45 that is engaged with the anchor bolt 44. The lower anchor has a hole 41a formed from an upper end surface in an axial direction, and the lower end of the anchor bolt is engaged with a female screw 41b formed on a bottom.SELECTED DRAWING: Figure 4

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a structure in which the leg portion of a column used for a building or a structure is joined to a foundation made of concrete.

  The structure which joins the leg part of a pillar to the foundation of concrete is widely used the structure using a plurality of anchor bolts which carried the lower part in concrete of the foundation. A plurality of the above anchor bolts can be joined, for example, to lock the upper end protruding from the upper surface of the base to the base plate fixed to the lower end of the pillar and press the base plate against the base. In such a structure, when a horizontal force is applied to the column, a bending moment is generated at the lower end of the column. When an earthquake or the like occurs, the horizontal force reverses the direction and repeatedly acts, and along with this, the bending moment also reverses the direction and repeatedly acts.

  As described above, when a bending moment acts on the lower end of the column, a pullout force acts on the anchor bolt on the tension side, and the anchor bolt is stretched. And on the compression side, the base plate is pressed against the foundation. The elongation of the anchor bolt becomes plastic deformation when the bending moment increases and the degree of stress exceeds the yield point. Thereafter, when the bending moment reverses direction, a compressive force acts on the region which was on the tension side and the base plate is strongly pressed against the base, and a tensile force acts on the anchor bolt on the portion which was on the compression side. When it is large, plastic elongation occurs.

  When the direction of bending moment reverses in this manner, if the anchor bolt and the base plate are not restrained in the compression direction of the anchor bolt, the anchor bolt returns to the position where the base plate is pressed against the foundation while stretching. As a result, a so-called slip phenomenon occurs.

  Patent Literatures 1 and 2 propose a structure that prevents such a slip phenomenon. In these structures, after the plastic deformation of the anchor bolt occurs, the base plate exerts a compressive force on the anchor bolt when the direction of the bending moment is reversed, and the plastic deformation of the anchor bolt is caused by the compressive deformation. Make it happen. As a result, the stress-strain history of the anchor bolt becomes a large loop, and energy of vibration is efficiently absorbed to effectively damp the vibration of a building or a structure.

JP-A-4-80428 JP-A-9-132941

However, the prior art has problems that the following solutions are desired.
As described above, even if the structure that causes plastic elongation and compressive deformation to the anchor bolt when bending moment acts in the direction to reverse repeatedly, plastic deformation remains in the anchor bolt after the earthquake motion is settled. There is something to do. It is desirable to eliminate residual deformation of the anchor bolt in order to restore a building or structure to a state before being subjected to seismic load. However, it is difficult to eliminate the residual deformation occurring in the anchor bolt, and in the conventional structure, the anchor bolt can not be replaced to be a new one.

  The present invention has been made in view of the above circumstances, and an object thereof is a column-to-base joint structure capable of absorbing energy such as vibration by plastic deformation of the anchor bolt and enabling replacement of the anchor bolt. To provide.

  In order to solve the above problems, the invention according to claim 1 comprises a foundation on which a main part is formed of concrete, a pillar erected on the foundation, and a base plate fixed to a lower end of the pillar. And a plurality of anchor members having a lower portion embedded in the base and an upper end projecting from the upper surface of the base and coupled to the base plate, the anchor member embedded in the concrete forming the base A male screw of a lower end portion is screwed into the female screw portion provided on the fixing member, and a portion above the portion screwed into the female screw portion is not in contact with concrete or mortar that constitutes the foundation And an anchor bolt, the upper end of which is supported by the upper surface of the base and protrudes to be coupled to the base plate. The present invention provides a column base joint structure capable of being pulled out of the fixing member by a rotational force about an axis applied to a portion which protrudes from the upper surface of the foundation, and which is twisted with the fixing member.

  In the present invention, the shape of the fixing member is not limited as long as the fixing member is such that the male screw portion provided at the lower end of the anchor bolt is twisted and resists the upward pulling force acting on the anchor bolt. . For example, it may be a nut, or may include a nut and a plate locked thereto. Alternatively, it may be a rod-like member having a bolt insertion hole in which the anchor bolt can be inserted in the axial direction, and a tip portion of the anchor bolt being twisted together in the bolt insertion hole. The rod-like member may also have an additional member to resist withdrawal of the foundation from the concrete.

  In this column-to-base joint structure, downward compressive force is transmitted from the column to the foundation via the base plate, and when a bending moment acts on the column base, the pull-out resistance force of the anchor member causes the base plate to move upward. Displacement is limited. In addition, the anchor bolt is allowed to extend without being in contact with the concrete or mortar of the foundation between the portion coupled to the base plate and the lower end portion screwed to the fixing member. As a result, when a large pulling force acts on the anchor bolt, plastic deformation occurs in a range in which the elongation is allowed, and a large energy can be absorbed by the deformation up to the fracture. When a large load acts on the anchor bolt and plastic deformation remains, etc., the anchor bolt can be pulled out from the fixing member by applying a rotational force around the axis to the top of the anchor bolt. Then, a new anchor bolt not deformed can be screwed into the fixing member from above the base, and the anchor bolt can be easily replaced.

  The invention according to claim 2 is the column-to-base joint structure according to claim 1, wherein the anchor bolt is configured to transmit an upward tensile force and a downward compressive force from the base plate; It shall be combined.

  In this column-to-column joint structure, when a large horizontal force acts on the top of the column and a large bending moment acts on the column base, a large plastic deformation may occur in the tension-side anchor bolt. Then, when a large horizontal force reverses the direction and repetitively acts as in the case of an earthquake, a compressive force acts on the anchor bolt which has become a tension side and a plastic elongation has occurred, and a compressive deformation occurs. As a result, the stress-strain curve of the anchor bolt becomes a large loop, and vibration energy can be effectively absorbed to obtain a damping effect.

  The invention according to claim 3 is the column / base joint structure according to claim 1 or 2, wherein the fixing member includes a rod body having an axis in the vertical direction, and an axial direction from an upper end surface of the rod body. A central hole is formed in the bottom of the central hole, and a female screw portion into which the male screw portion of the anchor bolt is screwed is formed.

In this column-to-base joint structure, the anchor bolt can be kept out of contact with the concrete or mortar of the foundation at the portion inserted into the central hole of the rod, and the bottom of the anchor bolt can be rotated by rotating the anchor bolt around its axis. It can be removed from the female screw and the anchor bolt can be easily replaced.
In this structure, the length of the rod can be determined by setting the length of the rod, and the length of the central hole formed in the axial direction from the upper end face of the rod can be determined. The length of the anchor bolt can be determined by Therefore, the embedding depth of the anchor member in the base and the length of the anchor bolt can be set independently of each other. As a result, it is possible to set the elongation of the anchor bolt until it yields by the tensile force acting on the anchor bolt, and the elongation until it breaks after yielding to appropriate values, and the length of the rod-like body The rod-like body can be embedded in the concrete of the foundation to a sufficient depth to have a sufficient pull-out resistance by setting.

  According to a fourth aspect of the present invention, in the column-base joint structure according to the third aspect, the rod-like body is provided with an enlarged portion whose cross section is enlarged at a lower end portion, or twisted with an external thread formed on an outer peripheral surface. It is assumed that a combined nut or the nut and a fixing plate to be locked to the nut are attached.

  The rod-like body has a large resistance to the pulling-out force from the concrete of the base by the enlarged portion, the nut or the fixing plate anchored to the nut.

  The invention according to claim 5 is the column / base joint structure according to claim 1 or 2, wherein the fixing member has a nut to be twisted with the male screw portion of the anchor bolt, and the nut from the nut It is assumed that a tubular member is mounted so as to surround the periphery of the anchor bolt up to the base plate.

In this column-to-base joint structure, the portion from which the nut of the anchor bolt is twisted together to the base plate can be surrounded by the tubular member to maintain the concrete or mortar forming the foundation and the anchor bolt in non-contact. Thus, the anchor bolt can be removed from the nut by rotating the anchor bolt about the axis, and the anchor bolt can be easily replaced.
In addition, since the nut is twisted with the anchor bolt, the nut resists the pulling force acting on the anchor bolt. This nut may be a long nut, a cap nut or the like as long as the anchor bolt is twisted without being in contact with the concrete or mortar of the base.

  The invention according to claim 6 is the column-to-base joint structure according to any one of claims 1 to 5, wherein the base plate has a frame raised upward from an upper surface, and the anchor bolt The upper end portion is connected to the upper portion of the frame through the plate-like main portion of the base plate.

  In this column-to-column joint structure, when the lower end of the column is displaced so as to float upward, the anchor bolt resists via the above-mentioned frame. Then, the anchor bolt can be coupled to the frame above the plate-like main body of the base plate in close contact with the base. Thus, the residual state of plastic deformation after the application of a large tensile force can be easily observed, and the necessity of replacement can be easily determined. In addition, the work of replacing the anchor bolt also becomes easy. In particular, it becomes easy to couple to the anchor bolt so that both tensile and compressive forces are transmitted from the base plate, and to release the coupling and replace the anchor bolt.

  The invention according to claim 7 relates to the column-to-base joint structure according to claim 6, wherein at least a portion of the anchor bolt is lower than a portion connected to the frame above the plate-like main body of the base plate. It is assumed that a metal cylinder is mounted so as to surround the outer peripheral surface of the anchor bolt.

  In this column-to-base joint structure, plastic deformation occurs in the anchor bolt, and thereafter, when compressive force is applied, the bending deformation of the anchor bolt is restrained and buckled above the plate-like main body of the base plate. Can be prevented.

  The invention according to claim 8 is the column-to-base joint structure according to any one of claims 1 to 7, wherein the base plate is higher than the lower surface by concrete of the foundation or mortar integrated with the foundation. The side surface of the base plate is inclined downward toward the center side of the base plate, and the side surface and the lower surface of the base plate have adhesion to the concrete of the base or the base and the base plate It is assumed that a peeling layer is formed to suppress the adhesion with the mortar inserted between the two.

  In this column-to-base joint structure, the base plate is embedded in concrete or mortar so that horizontal displacement is caused by the concrete or mortar being in contact with the side surface of the base plate when horizontal force is applied to the column. Are bound. Then, when the bending moment acts on the lower end of the column and the anchor bolt is stretched on the tension side and the base plate is lifted, the peeling layer separates the base plate from concrete or mortar easily, and concrete or mortar of the adjacent part Can be suppressed from being damaged. Then, when the direction of bending moment is reversed and the lifted base plate is again pressed against the foundation, the base plate is accurately restored to the original position by the inclined side surface.

  As described above, in the column end joint structure according to the present invention, energy such as vibration can be absorbed by plastic deformation of the anchor bolt, and the anchor bolt can be easily replaced. It is possible to restore the state before plastic deformation occurs.

They are a schematic front view and a schematic side view of pillar base connection structure which is one embodiment of the present invention. It is a plane sectional view in the AA shown in FIG. It is an elevation sectional view in the BB line shown in FIG.1 and FIG.2. It is sectional drawing of the anchor member currently used by the column base joining structure shown in FIG. It is the schematic which shows the process of joining a pillar on a foundation by the pillar base junction structure shown in FIG. It is the schematic which shows the process of joining a pillar on a foundation by the pillar base junction structure shown in FIG. It is the schematic which shows the process of joining a pillar on a foundation by the pillar base junction structure shown in FIG. It is the schematic which shows the process of joining a pillar on a foundation by the pillar base junction structure shown in FIG. It is sectional drawing which shows a part of anchor member and baseplate in pillar-column-part junction structure which is other embodiment of this invention. It is a schematic front view of pillar base connection structure which is other embodiment of this invention. It is sectional drawing which shows the anchor member used by the column base joint structure shown in FIG. It is sectional drawing which shows the other example of the anchor member which can be used by the column base junction structure shown in FIG.

Hereinafter, embodiments of the present invention will be described based on the drawings.
FIG. 1 is a schematic front view and a schematic side view showing a column-base joint structure according to an embodiment of the present invention. Moreover, FIG. 2 is a plane sectional view in the AA line in FIG.
This column-to-base joint structure is to joint the lower end portion of the column 1 made of wood material to the foundation 2. The pillar 1 is made of a laminated material in which wood of small cross section is laminated, and a base plate 3 made of steel is attached in contact with the lower surface. The lower part of the plurality of anchor members 4 is embedded in the concrete 21 of the base, the upper part protrudes from the upper surface of the base 2, and the base plate 3 is connected to the base 2 by these anchor members 4.

The cross-sectional shape of the pillar 1 is rectangular, and one side of the cross-section has a flat shape longer than the other adjacent side. And, it is joined to the foundation 2 so as to have a large resistance to a bending moment acting in the direction of the long side at the lower end.
A hole in the axial direction is formed in the center of the column 1, and the tendon 11 is inserted through the hole. The lower end of the tendon 11 is embedded in the concrete 21 of the foundation 2 and fixed. And tension is introduced in the upper part (not shown) of pillar 1, prestress is introduced to pillar 1, and pillar 1 is pressed against foundation 2 by axial force.

The base plate 3 has a plate-like main body 31 made of a thick steel plate, and a plurality of frames 32 raised on the upper surface of the plate-like main body 31. Then, the upper surface of the plate-like main body portion 31 is in contact with the lower end surface of the column 1 and is firmly joined. The lower portion of the plate-like main body portion 31 is embedded in a mortar layer 22 formed on the foundation concrete 21, and the vertical force transmitted from the column 1 is transmitted to the concrete portion through the mortar layer 22. It is supposed to be As shown in FIG. 1, in the side surface of the plate-like main body portion 31, the portion embedded in the mortar layer 22 is inclined to the center side. That is, the side surface is inclined so that the dimension of the lower surface is reduced from the upper surface.
A release agent is applied to the lower surface of the plate-like main body portion 31 to block adhesion with the mortar layer 22 formed so as to embed the lower portion of the plate-like main body portion 31 and to be easily peeled off. There is.

  The plurality of frames 32 raised on the upper surface of the plate-like main body portion 31 are provided at positions where the anchor members 4 are coupled, and made of steel and welded to the plate-like main body portion 31 of the base plate 3 It is fixed by Each of the frames 32 has two vertical members 32a which are raised above the upper surface of the plate-like main body 31, and a horizontal member 32b which connects the upper portions of the vertical members 32a in the horizontal direction. A through hole is formed between the positions of the plate-like main body portion 31 where the two vertical members 32a are raised. The upper portion of the anchor member 4 is inserted into the through hole, and the upper end portion of the anchor member 4 is coupled to the horizontal member 32 b through the space between the two vertical members 32 a.

  The base plate 3 is joined to the column 1 by a plurality of joining bolts 33, as shown in FIGS. The joint bolt 33 has a male screw formed over the entire length, and the lower end is twisted with the female screw of the bolt hole formed in the plate-like main body 31 of the base plate 3. Then, the upper part is inserted into the hole drilled in the column 1. An adhesive is filled in the gap between the inner peripheral surface of the hole and the outer peripheral surface of the joint bolt 33, and is hardened to bond the column 1 and the joint bolt 33. For example, an epoxy resin can be used as the adhesive.

The foundation concrete 21 has a plurality of height adjustment bolts 23 on the top surface. The lower part of these height adjusting bolts 23 is embedded in the concrete 21 and the long nut 24 is twisted on the upper part protruding from the upper surface. The base plate 3 can be placed on these long nuts 24 and temporarily supported. The base plate 3 can be temporarily supported at an accurate height by adjusting the length by which the long nut 24 is twisted to the height adjusting bolt 23.
The mortar layer 22 formed on the concrete of the foundation 2 is such that uncured mortar is poured onto the concrete 21 of the foundation in a state where the base plate 3 is temporarily supported by the height adjusting bolt 23 and the long nut 24 and hardened. Formed by Therefore, at least the lower part of the height adjustment bolt 23, the long nut 24, and the plate-like main body 31 is embedded, and the base plate 3 is supported on the concrete 21 of the foundation.

FIG. 4 is a cross-sectional view showing the anchor member 4 that connects the base 2 and the base plate 3.
The anchor member 4 includes a lower anchor 41 which is a rod-like body whose lower portion is embedded in concrete 21 of a foundation, an embedding nut 42 twisted on an external thread formed at the lower end of the lower anchor 41, and the embedding nut A fixing plate 43 locked at 42, an anchor bolt 44 joined to the upper portion of the lower anchor 41 and coupled to the base plate 3, and a nut 45 twisted with the anchor bolt 44 are provided.

  The lower anchor 41, the embedding nut 42, and the fixing plate 43 form the fixing member of the present invention, and the lower anchor 41 is embedded in the foundation concrete 21 to a predetermined depth. The fixing plate 43 is a steel plate having a through hole at the center, and the lower anchor 41 is inserted through the through hole, and the fixing plate 43 is locked to the embedded nut 42. Therefore, by the embedded nut 42 screwed to the male screw portion of the lower anchor 41 and the fixing plate 43 locked thereto, the base concrete 21 is firmly fixed so as not to come off the foundation concrete 21.

  In the lower anchor 41, a hole 41a is formed in the axial direction from the upper end face, and a female screw 41b that can be twisted with the anchor bolt 44 is formed in the bottom thereof. The depth of the hole, that is, the position where the female screw portion 41b is formed, is the rigidity, deformation performance or deformation that should be allowed before failure occurs in the joint of the lower end of the column determined in the design of the structure including the column 1. It can be appropriately determined by the amount etc.

The lower end portion of the anchor bolt 44 is connected to the lower anchor 41 by twisting to the female screw portion 41 b at the bottom of the hole 41 a provided in the lower anchor 41. A small annular gap is formed between the inner peripheral surface of the hole 41 a formed in the lower anchor 41 and the outer peripheral surface of the anchor bolt 44 above the part twisted together with the female screw portion 41 b.
The upper portion of the anchor bolt 44 is coupled to the cross member 32 b of the frame 32 provided on the base plate 3. A through hole 32c in the vertical direction is formed in the cross member 32b, and the anchor bolt 44 is inserted through the through hole 32c, and the head 44a is abutted on the upper surface of the cross member 32b via the washer 46. Then, a nut 45 screwed to the anchor bolt 44 on the lower side of the cross member 32b is tightened on the lower surface of the cross member 32b, and the anchor bolt 44 is displaced relative to the base plate 3 It has become.
The upper end surface of the lower anchor 41 is preferably pressed against the nut 45 tightened to the lateral member 32b, but the lower end of the anchor bolt 44 is twisted to the female screw 41b formed at the bottom of the hole 41a. The upper end surface of the lower anchor 41 may be separated from the nut 45 in the assembled state.

  In such a column-to-base joint structure, when a downward compressive force is transmitted from the column 1 to the foundation 2 via the base plate 3, and when an upward pulling force is applied to the column 1, the column 1 to the base plate 3 The pullout force is transmitted to the concrete 21 of the foundation through the anchor bolt 44, the lower anchor 41, the embedded nut 42 and the fixing plate 43, and the pullout is resisted. Also, when a bending moment acts on the column base, the compressive force is transmitted from the column 1 to the concrete 21 of the foundation on the compression side via the base plate 3 and the mortar layer 22 and the pulling force is applied to the column 1 on the tension side. It is transmitted to the concrete 21 of the foundation through the anchor member 4 in the same manner as when it acts, and resists pulling out.

  When a large bending moment acts on the column base and a stress degree higher than the yield point stress degree is generated in the tension-side anchor bolt 44, the anchor bolt 44 is twisted from the lower end anchor 41 to the frame 32 In a wide range up to the locked head, plastic deformation occurs. Then, when a large horizontal force reverses the direction and repeatedly acts as in the case of an earthquake, the region that was the tension side becomes the compression side and the base plate 3 is pressed against the foundation 2. At this time, since the anchor bolt 44 in which the plastic elongation has occurred is connected to the cross member 32 b by the head 44 a and the nut 45, a compressive force acts from the base plate 3 to cause a compressive deformation. As a result, when a bending moment that reverses cyclically acts, the stress-strain curve of the anchor bolt 44 becomes a large loop, effectively absorbing the energy of vibration and damping the vibration of the structure. When a force in the compression direction acts on the anchor bolt 44, the anchor bolt 44 is restrained from bending deformation on the opposing inner peripheral surface with an annular gap in the axial hole 41a of the lower anchor 41, The buckling of the anchor bolt 44 is prevented.

  As described above, when a large load acts on the structure and plastic deformation remains in the anchor bolt 44, etc., the anchor bolt 44 is fixed to the lower anchor by applying a rotational force around the axis to the head 44a of the anchor bolt. It can pull out from 41 internal thread part 41b. Then, a new anchor bolt without deformation can be screwed into the lower anchor 41 from above the base plate 3, and the anchor bolt 44 can be easily replaced and restored to the initial state before plastic deformation occurs. .

Next, the process of joining the pillar 1 made of wood material to the foundation 2 by the above structure will be described.
A formwork and necessary reinforcing bars for forming the foundation 2 are assembled at the position where the column 1 is erected, and unhardened concrete is driven in to form the concrete portion 21 of the foundation as shown in FIG. 5 (a). At this time, a cylindrical boxing mold having a bottom is installed at a position where the anchor member is to be embedded, and a hole 25 of a predetermined depth is formed from the upper surface. In addition, the lower side portion 11a of the tendon to which the fixing tool 12 is attached at the lower end portion is disposed at the center of the column 1 so that the lower portion is embedded in the concrete.

On the other hand, the pillar 1 made of wood material is supported with its axial direction horizontal in a factory or the like, and the base plate 3 made of steel is attached. The base plate 3 can be attached, for example, as follows.
As shown in FIG. 5B, the base plate 3 is temporarily fixed at a predetermined position of the column 1 by a screw or the like, and the joint bolt 33 is screwed into the female screw of the bolt hole 31a provided in the base plate 3 from the back side. Then, it is inserted into a hole 13 provided in the column 1 while being rotated about its axis, and screwed in to a position where the rear end of the joint bolt 33 substantially coincides with the lower surface of the base plate 3. At this time, the joint bolt 33 is supported by the twisted base plate 3, and an annular gap can be formed between the joint bolt 33 and the inner peripheral surface of the hole 13 formed in the column 1. The adhesive is filled in the gap and hardened to bond the base plate 3 and the column 1 via the joint bolt 33.

The pillar 1 to which the base plate 3 is attached is lifted with the axis line in the vertical direction as shown in FIG. 6 (a). In the column 1 to be lifted, the upper portion 11b of the tendon is inserted into an axial hole formed at the center and supported by the fixing tool 14 on the upper side. And while attaching the anchor member 4 to the base plate 3 attached to the lower end part of the pillar 1 as shown in FIG.6 (b), a release agent is attached to the lower surface and the side of the plate-like main part 31 of the base plate 3. Apply The pillar 1 on which the anchor member 4 is mounted is lowered on the cast concrete 21 and inserted into the hole 25 formed in the concrete as shown in FIG. 7A. The column 1 is precisely adjusted as shown in FIG. 7 (b) by adjusting the height adjusting bolt 23 provided on the upper surface of the concrete 21 of the foundation and the long nut 24 screwed thereto. Temporarily support.
Further, the tendon 11 connects the lower portion 11 a partially embedded in the concrete 21 of the foundation and the upper portion 11 b supported by the column 1 by the coupler 15 in the opening 1 a provided in the column Do.

  In this state, a mortar form 26 is set on the upper part of the foundation concrete 21 and the uncured mortar 27 is poured. The mortar 27 is also poured into the hole 25 into which the anchor member 4 is inserted, and is embedded in the hole so that the anchor member 4 is integrated with the concrete 21 of the foundation. Moreover, the mortar 27 pours in to the height which embeds at least the lower part of the plate-shaped main-body part 31 of a baseplate. After hardening of the mortar 27 poured in this way, tension is introduced into the tendon 11 at the top of the column 1. Thereby, as shown in FIG. 8, the pillar 1 is fixed to the concrete 21 of the foundation via the base plate 3, the mortar layer 22 and the anchor member 4.

  The anchor member applied to the present invention is not limited to the example shown in FIG. 4. For example, the lower anchor shown in FIG. 4 is obtained by separating the upper cylindrical portion of the portion where the internal thread is formed from the upper end surface. It may be By separating the lower anchor into the portion to which the anchor bolt is connected and the cylindrical member surrounding the periphery of the anchor bolt, the internal thread at the bottom of the hole can be formed at a shallow position, which facilitates processing. Further, buckling of the anchor bolt can be effectively prevented by the tubular member.

Moreover, the anchor member can also use the thing of a structure as shown in FIG.
The anchor member 5 includes the lower anchor 51, the embedded nut 52, the fixing plate 53, and the anchor bolt 54, but does not include the nut to be twisted with the anchor bolt 54. When the anchor member 5 is adopted, a female screw is formed on the inner peripheral surface of the through hole provided in the lateral member 62 b of the frame 62 raised from the plate-like main portion 61 of the base plate 6, The anchor bolt 54 can be screwed in. Thereby, both the force in the tension direction and the force in the compression direction are transmitted from the frame 62 of the base plate 6 to the anchor bolt 54.

  The two vertical members 62a of the frame 62 of this embodiment are erected at a position close to the outer peripheral surface of the anchor bolt 54, and desirably, the vertical member 62a forms a groove having an arc shape in cross section It is assumed that the inner circumferential surface and the outer circumferential surface of the anchor bolt 54 are in close proximity and face each other. As a result, the longitudinal members 62a of the frame 62 can restrain bending deformation in all directions of the anchor bolt 54 and prevent buckling. The longitudinal member of the frame may be cylindrical and surround the anchor bolt 54.

  The lower anchor 51 of the anchor member 5 of the present embodiment has the upper end surface at substantially the same height as the upper surface of the plate-like main portion 61 of the base plate 6 and the frame 62 in the through hole formed in the plate-like main portion 61 The vertical member 62 a of the frame 62 is held in abutment with the step portion between the two. An internal thread is formed from the upper end face on the inner peripheral surface of the hole 51a formed in the axial direction from the upper end face of the lower anchor 51, and the lower end portion of the anchor bolt 54 is twisted to connect the anchor bolt 54 and the lower anchor 51 It is done. In addition, the hole 51a formed in the axial direction from the upper end surface of the lower anchor 51 can also be formed deeper than that shown in FIG. A female screw may be formed by limiting the bottom of the hole, and a hole with an inner diameter slightly larger than the outer diameter of the anchor bolt may be formed above the female screw.

When such an anchor member 5 is used, it functions in substantially the same manner as the anchor member 4 shown in FIG. 4 and the anchor bolt 54 is pulled out by rotating the head about the axis above the frame 62. The anchor bolt 54 can be replaced when plastic deformation remains.
The anchor member 4 shown in FIG. 4 and the anchor member 5 shown in FIG. 9 both twist the nuts on the lower anchors 41 and 51 and lock the fixing plate, but instead the lower end of the lower anchor The diameter of the portion may be increased. Moreover, what has a rod-like or plate-like overhang | projection part by means, such as welding, etc. may be used.

FIG. 10 is a schematic front view of a column-to-base joint structure according to another embodiment of the present invention, and FIG. 11 is a cross-sectional view showing an example of an anchor member that can be used in this column-to-base joint structure. .
In this column-to-base joint structure, no frame is provided on the base plate 8, and the head 74 a of the anchor bolt 74 of the anchor member 7 abuts on and is coupled to the upper surface of the plate-like main portion 81 of the base plate 8. ing.
In addition to the anchor bolt 74, the anchor member 7 is twisted with the anchor bolt, and the plate-like main body 81 is pinched between the head portion 74a of the anchor bolt and tightened. , A tubular member 71 mounted so as to surround the anchor bolt 74 between the nut 75 and the fixing plate 73. And. The embedded nut 72 and the fixing plate 73 constitute a fixing member of the present invention.

The embedded nut 72 is twisted with the tip of the anchor bolt 74, and the tip end surface of the anchor bolt 74 is within the axial dimension of the embedded nut 72 so that the tip does not protrude from the embedded nut 72. The embedded nut 72 has a length that can hold the anchor bolt 74 so as not to come out in such a twisted state. Under the hollow hole of the embedded nut 72, it can be made non-contact with the mortar 28 filled around by a means such as inserting a shielding member 76. This allows the anchor bolt 74 to be pulled out of the embedded nut 72 by being rotated on the upper side of the base plate 8.
The fixing plate 73 is engaged with the embedded nut 72 and resists the withdrawal of the anchor member 7.
The embedded nut 72 may use a cap nut whose one end in the axial direction is closed.

  A nut 75 screwed to the anchor bolt 74 and tightened to the lower surface of the plate-like main body 81 is covered by a nut cover 82 fixed to the lower surface of the plate-like main body 81. And the concrete 28 and the mortar 28 to be filled in between. As a result, the nut 75 can be displaced horizontally with the anchor bolt 74 within a range where displacement of the anchor bolt 74 is permitted without being restricted by the mortar 28. When the position of the nut 75 is restrained by the mortar 28, when a large bending moment and horizontal force act on the lower end of the column to cause displacement of the base plate 8, an anchor bolt is formed between the nut 75 and the base plate 8. There is a possibility that 74 may be pinched to make extraction difficult, which is to be avoided.

  The cylindrical member 71 has an inner diameter slightly larger than the outer diameter of the anchor bolt 74, and an annular gap is formed around the anchor bolt 74. The clearance is of such a size as to restrain bending by restraining the bending deformation of the anchor bolt when compressive force is applied to the anchor bolt 74. The upper end surface of the cylindrical member 71 is in contact with the lower surface of the nut cover 82, and the lower end surface is in contact with the upper surface of the fixing plate 73. As a result, the mortar 28 and the anchor bolt 74, which are filled to fix the anchor member 7 integrally with the concrete 21 of the foundation, will be kept in non-contact, and the anchor bolt 74 may be axially rotated from above the base plate 8. It is possible to remove by rotating.

The cylindrical member 71 used in the anchor member 7 shown in FIG. 11, the embedded nut 72 twisted with the anchor bolt 74, and the fixing plate 73 engaged with the embedded nut 72 are replaced with these as shown in FIG. Lower anchor 91, an embedded nut 92 screwed to the lower anchor 91, and a fixing plate 93 can be employed.
The lower anchor 91 has a hole 91a formed in the axial direction from the upper end face similarly to the lower anchor 41 used in the column and leg joint structure shown in FIG. 4 and the anchor bolt 94 is provided at the bottom of the hole 91a. It has an internal thread portion 91b whose distal end portion is twisted together. Further, the inner peripheral surface of the hole 91a is opposed to the outer peripheral surface of the anchor bolt 94 with an annular gap above the female screw portion 91b.

The upper end surface of the lower anchor 91 is in contact with the lower surface of the nut cover 82 attached to the plate-like main portion 81 of the base plate, and an external thread is formed on the outer peripheral surface of the lower portion. The fixing plate 93 is locked.
On the other hand, the anchor bolt 94 has its tip end twisted with the female screw portion 91 b of the lower anchor 91 and connected to the lower anchor 91, and the base plate 81 is sandwiched between the head 94 a and the nut 95.
Even if such an anchor member 9 is used, the anchor bolt 94 can be easily replaced while functioning in substantially the same manner as the anchor member 7 shown in FIG.

  In the embodiment described above, the columns are made of wood, but the present invention is not limited to joining the legs of the columns made of wood, but using the base plate at the lower end of the columns. If it is, it can apply to the joint structure of the leg of a steel pillar and a pillar which consists of precast concrete. Further, the column-to-base joint structure of the present invention is not limited to the above embodiment, and the shape, size, etc. can be changed and applied within the scope of the present invention.

1: Column, 1a: Column opening, 2: Foundation, 3: Base plate, 4: Anchor member, 5: Anchor member, 6: Base plate, 7: Anchor member, 8: Base plate, 9: Anchor member,
11: tendon, 11a: lower part of tendon, 11b: upper part of tendon, 12: anchorage, 13: hole provided in column, 14: anchorage, 15: coupler,
21: Foundation concrete, 22: mortar layer, 23: height adjustment bolt, 24: long nut, 25: hole formed in foundation concrete, 26: formwork for mortar, 27: uncured mortar, 28: Mortar,
31: plate-like main body, 31a: bolt hole provided in plate-like main body, 32: frame, 32a: longitudinal member of frame, 32b: lateral member of frame, 32c: penetration provided in lateral member Hole 33: Joint bolt,
41: lower anchor, 41a: hole axially formed from end face of lower anchor, 41b: internal thread at bottom of hole, 42: embedded nut, 43: anchor plate, 44: anchor bolt, 44a: head of anchor bolt Part 45: Nut 46: Washer
51: lower anchor, 51a: hole axially provided from the end face of lower anchor, 52: embedded nut, 53: anchor plate, 54: anchor bolt,
61: plate-like main portion of base plate, 62: frame, 62a: vertical member of frame, 62b: horizontal member of frame,
71: Tubular member, 72: Embedded nut, 73: Anchor plate, 74: Anchor bolt, 74a: Head of anchor bolt, 75: Nut, 76: Shield member,
81: Plate-like main portion of base plate, 82: Nut cover,
91: lower anchor, 91a: hole axially provided from end face of lower anchor, 91b: internal thread at bottom of hole, 92: embedded nut, 93: anchor plate, 94: anchor bolt, 94a: head of anchor bolt Part, 95: Nut

Claims (8)

A foundation whose main part is formed of concrete,
A pillar standing on the foundation,
A base plate fixed to the lower end of the pillar;
And a plurality of anchor members having a lower portion embedded in the base and an upper end projecting from the upper surface of the base and coupled to the base plate;
The anchor member is
A fixing member embedded and fixed in the concrete forming the foundation;
The male screw at the lower end is screwed into the female screw provided on the fixing member, and the upper part from the portion screwed into the female screw is maintained in non-contact with the concrete or mortar constituting the foundation, and the upper end is the foundation And an anchor bolt protruding from the upper surface of the base plate and coupled to the base plate;
The anchor-bolt joint structure according to claim 1, wherein the anchor bolt is twistable with the fixing member so as to be able to be removed from the fixing member by a rotational force about an axis applied to a portion protruding from the upper surface of the foundation.   The column base joint structure according to claim 1, wherein the anchor bolt is coupled to the base plate such that an upward tensile force and a downward compressive force are transmitted from the base plate.   The fixing member includes a rod-like member having an axis in the vertical direction, and a central hole is formed in the axial direction from the upper end surface of the rod, and a female screw portion into which the male screw portion of the anchor bolt is screwed at the bottom of the central hole. The column base joint structure according to claim 1 or 2, characterized in that:   The rod-like body is provided with an enlarged portion whose lower end is enlarged in cross section, or a nut screwed to an external thread formed on an outer peripheral surface, or the nut and a fixing plate engaged with the nut are attached. The column base joint structure according to claim 3, characterized in that:   The fixing member has a nut which is screwed to the male screw portion of the anchor bolt, and a tubular member is attached between the nut and the base plate so as to surround the periphery of the anchor bolt. The column base joint structure according to claim 1 or 2, characterized by the above. The base plate has a frame raised upward from the upper surface,
The column support according to any one of claims 1 to 5, wherein the anchor bolt penetrates the plate-like main body of the base plate and an upper end is coupled to an upper portion of the frame. Junction structure.   A metal cylinder is attached to the anchor bolt so as to surround the outer peripheral surface of the anchor bolt at least at a portion below the portion coupled to the frame above the plate-like main body of the base plate The column-to-base joint structure according to claim 6, characterized in that: The base plate is embedded by the concrete of the base or a mortar integrated with the base to a position higher than the lower surface,
The side surface of the base plate is inclined downward toward the center side of the base plate,
The side surface and the lower surface of the base plate are characterized in that a peeling layer is formed which suppresses the adhesion of the foundation to the concrete or the adhesion between the foundation and the mortar inserted between the foundation and the base plate. The column base joint structure according to any one of claims 1 to 7.

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