JP6829631B2 - Construction method of column base, reinforcement method of existing column base - Google Patents

Description

The present invention relates to a method of constructing a column base and a method of reinforcing an existing column base.

As an exposed column base structure such as a steel column, a base plate is usually joined to the lower part of the column, and the base plate is fixed to concrete such as a foundation with anchor bolts (for example, Patent Document 1).

To support the base plate when constructing a pillar, it is common to install a mortar (center coating mortar) on the foundation at a position corresponding to the center of the base plate and place the base plate on the mortar. On the other hand, it is also possible to support the base plate by inserting anchor bolts into the through holes of the base plate and sandwiching the base plate from above and below with nuts attached to the anchor bolts above and below the base plate.

Japanese Unexamined Patent Publication No. 2016-108810

However, when installing a mortar for supporting the base plate as in the former case, it takes time and effort for construction and supervision related to the mortar, and a curing period until the strength of the mortar is developed is also required.

On the other hand, when supporting with nuts as in the latter case, mortar is not always necessary, so construction is easy, but the nut on the lower side of the base plate cannot be removed after construction, and the anchor bolt can be used with the nut. Durability problems may occur.

For example, in the case of a column base structure that uses reinforcing bars for anchor bolts and attaches them between the reinforcing bars and the foundation, if there are nuts on the top and bottom of the base plate, the vertical moments in the vertical plane will be applied to the columns in the event of an earthquake. In addition, when the base plate reciprocates up and down from the reference position, the anchor bolts are repeatedly deformed by tension and compression. This is because when the anchor bolts are fixed to the base plate by the nuts above and below the base plate, all the reciprocating deformations of the base plate are also applied to the anchor bolts. In this way, the compressive force and the tensile force repeatedly act on the anchor bolt from the base plate fixed with the nut, which may reduce the adhesive force of the reinforcing bar and make it easier to pull out.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a method of constructing a column base which is easy to construct and can avoid the problem of durability, a method of reinforcing an existing column base, and the like. And.

In order to solve the above-mentioned problems, the first invention is a method of constructing a column base, in which an intermediate removable nut is attached to an anchor bolt embedded in a foundation, and the column is joined onto the intermediate removable nut. The base plate is placed, the base plate is fixed to the anchor bolt by a nut, the position of the pillar is fixed, the intermediate removable nut is removed, and mortar is filled between the foundation and the base plate. This is a column base construction method characterized by.

It is also desirable that the intermediate removable nut has a U-shaped nut member and is removable from the side of the anchor bolt.

According to the first invention, the base plate can be supported by the above-mentioned nut and the intermediate removable nut at the time of constructing the column, and the above-mentioned mortar for supporting the base plate can be omitted. Therefore, the labor of construction and supervision related to the mortar is reduced, and the curing period of the mortar is not required, so that the construction period can be shortened.

Further, since the intermediate removable nut can be removed after fixing the position of the pillar, the problem of durability as described above does not occur. For example, since the nut is fixed only on the upper side of the base plate, the base plate moves upward in the event of an earthquake, and the base plate penetrates the anchor bolt after the upper nut also applies tensile force to the anchor bolt. Since it only moves up and down with respect to the anchor bolt passed through the hole, the compressive force and the tensile force do not repeatedly act on the anchor bolt.

Further, as the intermediate detachable nut, for example, a nut having a U-shaped nut member and which can be attached and detached from the side of the anchor bolt can be used, and the intermediate detachable nut can be easily attached and detached.

The second invention is a method for reinforcing an existing column base, in which an intermediate detachable nut is attached to an anchor bolt embedded in a foundation in the vicinity of the existing column base, and a reinforcing column is formed on the intermediate removable nut. The joined base plate is arranged, the base plate is fixed to the anchor bolt by a nut, the reinforcing column is joined to the column of the existing column base, the intermediate removable nut is removed, and the foundation and the base plate are separated. This is a method for reinforcing existing column bases, which is characterized by filling mortar between them.

It is also desirable that the intermediate removable nut has a U-shaped nut member and is removable from the side of the anchor bolt.

It is also desirable that the base plate is fixed to the anchor bolt on the side far from the existing column base, and the side of the base plate close to the existing column base is arranged so as to wrap above the base plate of the existing column base. ..

According to the second invention, when the existing column base is reinforced by the reinforcing column, the base plate of the reinforcing column is supported by the above nut and the intermediate removable nut when the reinforcing column is constructed, and the reinforcing column is attached to the existing column base. By removing the intermediate detachable nut after joining to the pillar and fixing the position, the same effect as that of the first invention can be obtained.

For example, in seismic retrofitting of existing column bases, construction is often performed while using existing buildings such as factories, and the effect of shortening the construction period is very large because the curing period of the mortar for supporting the base plate is eliminated.

Further, in the case where the base plate of the existing column base is projected below the base plate of the reinforcing column, there may be no space for installing the mortar for supporting the base plate of the reinforcing column, and in the second invention, even in such a case, it is intermediate with the nut. Supporting the base plate of the reinforcing column with a removable nut has the advantage of facilitating construction.

Also in this second invention, by using a U-shaped nut member that is removable from the side of the anchor bolt as the intermediate removable nut, the intermediate removable nut can be easily attached and detached. Become.

A third invention is a method for reinforcing an existing column base having a base plate at the lower end portion, wherein an intermediate removable nut is attached to an anchor bolt embedded in a foundation in the vicinity of the existing column base, and the intermediate removable nut is attached. A widening base plate for widening the base plate is arranged on the top, the widening base plate is fixed to the anchor bolt by a nut, the widening base plate is joined to the existing column base, and the intermediate removable nut. Is a method for reinforcing an existing column base, which comprises removing the bolt and filling a mortar between the foundation and the widening base plate.

It is also desirable that the intermediate removable nut has a U-shaped nut member and is removable from the side of the anchor bolt.

According to the third invention, when the existing column base is reinforced by using the widening base plate for widening the base plate of the existing column base, the widening base plate is supported by the above nut and the intermediate removable nut to widen the width. By joining the base plate for use to the base plate of the existing column base to fix the position and then removing the intermediate removable nut, the same effect as that of the first invention can be obtained.

Also in the third invention, by using a U-shaped nut member that is removable from the side of the anchor bolt as the intermediate removable nut, the intermediate removable nut can be easily attached and detached. Become.

According to the present invention, it is possible to provide a method for constructing a column base, a method for reinforcing an existing column base, and the like, which are easy to construct and can avoid the problem of durability.

The figure which shows the reinforcement structure 1. The figure which shows the reinforcement structure 1. The figure explaining the reinforcement method of the existing column base. The figure which shows the intermediate detachable nut 35. The figure which shows the attachment method of the intermediate detachable nut 35. The figure explaining the reinforcement method of the existing column base. The figure explaining the reinforcement method of the existing column base. The figure explaining the reinforcement method of the existing column base. The figure which shows the column base structure 41. The figure which shows the column base structure 41. The figure explaining the construction method of the column base structure 41. The figure explaining the construction method of the column base structure 41. The figure explaining the construction method of the column base structure 41. The figure explaining the construction method of the column base structure 41. The figure which shows the reinforcement structure 71. The figure which shows the reinforcement structure 71. The figure explaining the reinforcement method of the existing column base. The figure explaining the reinforcement method of the existing column base. The figure explaining the reinforcement method of the existing column base. The figure explaining the reinforcement method of the existing column base. The figure which shows the intermediate detachable nut 65.

Hereinafter, the first embodiment of the present invention will be described. 1 and 2 are views showing a reinforcing structure 1 constructed by the method for reinforcing an existing column base according to the first embodiment of the present invention. Note that FIG. 1 is a vertical cross section taken along line AA of FIG. 2, and FIG. 2 is a horizontal cross section taken along line BB of FIG. The reinforcing structure 1 is a reinforcing structure in which an existing column base made of an existing column 3, a base plate 5, or the like is reinforced by a reinforcing column 23.

The reinforcing structure 1 is a seismic retrofitting of the existing column base by joining the reinforcing column 23 to the existing column 3. The existing columns 3 and the reinforcing columns 23 are provided on the foundation 2.

The foundation 2 has a step, and the existing pillar 3 is provided on the upper stage of the foundation 2. The existing column 3 is a steel column formed of steel or the like. The existing column 3 is, for example, an assembled column composed of a plurality of trusses, but may be another prism or an H-steel column. In the present embodiment, the existing pillar 3 has a substantially rectangular plane.

A base plate 5 is joined to the lower end of the existing pillar 3 by welding or the like. The base plate 5 is a substantially rectangular plate material, and through holes 7 are provided in the vicinity of the four corners of the plane thereof. The existing pillar 3 has its long side direction and short side direction aligned with each other in the long side direction and short side direction of the base plate 5, and is joined to substantially the center of the base plate 5.

A mortar 9 is provided between the upper stage of the foundation 2 and the base plate 5. A plurality of anchor bolts 11 are embedded in the upper stage of the foundation 2. For example, a threaded reinforcing bar or the like is used for the anchor bolt 11, and the anchor bolt 11 is configured to adhere between the reinforcing bar and the foundation 2 or the like. Each anchor bolt 11 is inserted into each through hole 7 of the base plate 5 through the mortar 9, and the nut 13 is tightened from above the base plate 5 to the upper end portion of the anchor bolt 11 protruding from the through hole 7. It is also possible to omit the mortar 9 and provide the base plate 5 directly on the foundation 2.

In this way, the existing pillar 3 and the base plate 5 are installed on the foundation 2. The shapes of the existing pillars 3 and the base plate 5, the arrangement and the number of anchor bolts 11 and the like are not limited to the above examples.

Reinforcing columns 23 are arranged outside the existing columns 3. The reinforcing column 23 is a steel frame column formed of a steel material or the like. The reinforcing column 23 is, for example, an assembled column in which steel materials are combined in a square shape, but may be another prism or an H-steel column. The reinforcing column 23 is arranged outside one short side (the short side on the left side of FIG. 2) of the plane of the existing column 3. The height of the reinforcing column 23 is, for example, about 1 to 2 m, but the height is not limited to this.

A base plate 25 is joined to the lower end of the reinforcing column 23 by welding or the like. The base plate 25 is a substantially rectangular plate material. The long side direction of the base plate 25 coincides with the short side direction of the base plate 5, and the end portion of the base plate 25 near the existing column 3 (the right end portion of FIGS. 1 and 2) is the reinforcing column 23 of the base plate 5. It is arranged so as to wrap above the end on the side closer to (the left end in FIGS. 1 and 2).

The reinforcing column 23 is joined to the end of the base plate 25 on the side closer to the existing column 3. The reinforcing column 23 may be joined to the base plate 25 in advance, or the reinforcing column 23 may be joined to the base plate 25 at the site. By joining the reinforcing column 23 to the base plate 25 in advance, the welding work at the site can be reduced and the joining can be performed more accurately.

On the other hand, at the end portion of the base plate 25 on the side far from the existing pillar 3 (the left end portion in FIGS. 1 and 2), through holes 27 are provided near both ends in the long side direction of the base plate 25.

A mortar 21 is provided under the base plate 25. The mortar 21 also covers the end portion of the base plate 5 on the side close to the reinforcing column 23. In FIGS. 1 and 2, a portion embedded in the mortar 21 below the base plate 25 is also shown by a dotted line for explanation.

In the vicinity of the existing pillar 3, an anchor bolt 31 is buried in the lower stage of the foundation 2. In the present embodiment, the anchor bolt 31 is a post-installed anchor, the lower portion thereof is inserted into a hole 30 formed in the lower stage of the foundation 2, and a solidifying material 32 such as mortar is filled around the hole 30. For example, a threaded reinforcing bar or the like is used for the anchor bolt 31, and the anchor bolt 31 is configured to adhere between the reinforcing bar and the solidifying material 32 or the like.

The anchor bolt 31 passes through the mortar 21 and is inserted into the through hole 27 of the base plate 25. The nut 33 is tightened from above the base plate 25 to the upper end of the anchor bolt 31 protruding from the through hole 27.

In this way, the reinforcing columns 23 and the base plate 25 are installed on the foundation 2. The shape, arrangement, number, and the like of the reinforcing columns 23 are not particularly limited. For example, it is possible to provide the reinforcing columns 23 on the outside of both short sides of the plane of the existing columns 3. Similarly, the shape, arrangement and number of base plates 25, arrangement and number of anchor bolts 31 and the like are not limited to the above examples. Further, a notch may be provided instead of the through hole 27.

The reinforcing column 23 is joined to the existing column 3. In the present embodiment, the splicing plate 29 is welded to the reinforcing column 23 and the existing column 3, whereby the reinforcing column 23 is joined to the existing column 3. The shape, position, etc. of the splicing plate 29 are not particularly limited. Further, the splicing plate 29 is not limited to one place, and may be provided at a plurality of places.

Next, the construction method of the reinforcing column 23 (the method of reinforcing the existing column base) will be described. In the present embodiment, first, as shown in FIG. 3, a hole 30 is formed in the lower stage of the foundation 2 and a solidifying material 32 is provided in the hole 30 in the vicinity of the existing pillar 3, and the lower portion of the anchor bolt 31 is provided therein. To insert. Then, an intermediate removable nut 35 (also referred to as an intermediate insertion type nut) is attached to the upper part of the anchor bolt 31 protruding above the foundation 2.

FIG. 4 is a diagram showing an intermediate removable nut 35. FIG. 4A is a view showing a plane of the intermediate removable nut 35, and FIG. 4B is a view of the intermediate removable nut 35 viewed from the direction of the recess 35b.

The intermediate removable nut 35 is formed by connecting two upper and lower nut members 35a and 35a so as to be relatively rotatable around the center of a plane thereof. Each of the nut members 35a and 35a has a U-shape, the semicircular portion at the tip of the recess 35b is in the center of the plane of the nut member 35a, and the female screw 35c is formed in the semicircular portion.

The intermediate removable nut 35 is arranged as shown in FIG. 5A by aligning the positions of the recesses 35b of the two upper and lower nut members 35a and 35a, inserting the anchor bolts 31 into the recesses 35b from the side. After that, as shown in FIG. 5B, one nut member 35a is rotated and fixed by a predetermined angle (for example, 180 °).

In the present embodiment, after attaching the intermediate removable nut 35 to the anchor bolt 31 as described above, as shown in FIG. 6, the upper end portion of the anchor bolt 31 is inserted into the through hole 27 of the base plate 25 to insert the base plate 25. Is placed on the intermediate removable nut 35, the nut 33 is tightened from above the base plate 25 to the upper end of the anchor bolt 31, and the base plate 25 is fixed to the anchor bolt 31 by the nut 33.

As described above, the reinforcing column 23 is joined to the end of the base plate 25 on the side close to the existing column 3, and the base plate 25 is supported by the nut 33 and the intermediate removable nut 35 when the reinforcing column 23 is constructed. .. The end of the base plate 25 near the existing column 3 is arranged so as to wrap above the end of the base plate 5 near the reinforcing column 23, and the base plate 25 is arranged at the end far from the existing column 3 at the end. It will be fixed to the anchor bolt 31 by the nut 33.

After that, as shown in FIG. 7, the splicing plate 29 is welded to the reinforcing column 23 and the existing column 3, and the reinforcing column 23 is joined to the existing column 3. As a result, the position of the reinforcing column 23 is fixed, so that the intermediate removable nut 35 is removed as shown in FIG. The intermediate removable nut 35 can be removed by aligning the recesses 35b of both nut members 35a and then pulling out the intermediate removable nut 35 from the side of the anchor bolt 31.

Then, the mortar 21 is filled between the foundation 2 and the base plate 25 as shown in FIG. When the mortar 21 is solidified, the reinforcing structure 1 of the existing column base is formed.

As described above, according to the present embodiment, when the existing column base is reinforced by the reinforcing column 23, the base plate 25 of the reinforcing column 23 can be supported by the nut 33 and the intermediate removable nut 35 when the reinforcing column 23 is constructed. The mortar for supporting the base plate described above can be omitted. Therefore, the labor of construction and supervision related to the mortar is reduced, and the curing period of the mortar is not required, so that the construction period can be shortened. For example, in seismic retrofitting of existing column bases, construction is often carried out while using existing buildings such as factories, and the effect of shortening the construction period by eliminating the curing period of mortar is very large.

Further, in the case of seismic retrofitting by the reinforcing column 23, the mortar for supporting the base plate of the reinforcing column 23 is used because there is a difference in height at the level of mortar construction and the height of the mortar becomes large because the foundation level is low. There are cases where the construction is complicated, but there is no such problem when the reinforcing column 23 is supported by the nut 33 and the intermediate removable nut 35.

In particular, in the case where the base plate 5 of the existing column base projects below the base plate 25 of the reinforcing column 23 as in the present embodiment, there may be no space for installing the mortar for supporting the base plate of the reinforcing column 23. In the embodiment, even in such a case, there is an advantage that the construction can be facilitated by supporting the base plate 25 by the nut 33 and the intermediate removable nut 35.

Further, in the present embodiment, since the intermediate removable nut 35 can be removed after fixing the position of the reinforcing column 23, the problem of durability as described above does not occur. The intermediate detachable nut 35 has U-shaped nut members 35a and 35a and can be attached and detached from the side of the anchor bolt 31, so that the intermediate removable nut 35 can be easily attached and detached.

Next, the second embodiment will be described. The second embodiment is to construct a new column base by the same method as that of the first embodiment.

FIG. 9 is a diagram showing a column base structure 41 (column base) constructed by the column base construction method according to the second embodiment, and FIG. 10 is a horizontal cross section along line CC of FIG. Is. The column base structure 41 has a column 43, a base plate 45, and the like. The pillar 43 is provided on the foundation 42, and the upper end thereof is joined to the beam 61. The column 43 is a steel column formed of steel or the like. The column 43 is, for example, a prism, but as described above, it may be an assembly column composed of a plurality of trusses or an H steel column.

A base plate 45 is joined to the lower end of the pillar 43 by welding or the like. The base plate 45 is a substantially rectangular plate material, and a through hole 47 is provided. Like the base plate 25, the through holes 47 are provided near the four corners of the plane of the base plate 45, and the pillar 43 is joined to substantially the center of the base plate 45.

A mortar 49 is provided between the foundation 42 and the base plate 45. A plurality of anchor bolts 51 are embedded in the foundation 42. For example, a threaded reinforcing bar or the like is used for the anchor bolt 51, and the anchor bolt 51 is configured to adhere between the reinforcing bar and the foundation 42 or the like. Each anchor bolt 51 is inserted into each through hole 47 of the base plate 45 through the mortar 49, and the nut 53 is tightened from above the base plate 45 to the upper end portion of the anchor bolt 51 protruding from the through hole 47. It is also possible to omit the mortar 49 and provide the base plate 45 directly on the foundation 42.

In this way, the pillar 43 and the base plate 45 are installed on the foundation 42. The shapes of the columns 43 and the base plate 45, the arrangement and the number of anchor bolts 51, and the like are not limited to the above examples.

Next, the construction method of the column base structure 41 will be described. In the present embodiment, first, as shown in FIG. 11, an intermediate removable nut 35 is attached to the upper portion of the anchor bolt 51 protruding above the foundation 42, as described above.

Next, as shown in FIG. 12, the upper end of the anchor bolt 51 is inserted into the through hole 47 of the base plate 45, the base plate 45 is placed on the intermediate removable nut 35, and the anchor bolt 51 is placed on the base plate 45. The nut 53 is tightened to the upper end portion, and the base plate 45 is fixed to the anchor bolt 51 by the nut 53. As a result, the base plate 45 is supported by the nut 53 and the intermediate removable nut 35 when the pillar 43 is constructed.

After that, as shown in FIG. 13, the upper end portion of the column 43 is joined to the beam 61. As a result, the position of the pillar 43 is fixed, so that the intermediate removable nut 35 is removed as shown in FIG. Then, the mortar 49 is filled between the base 42 and the base plate 45 as shown in FIG. When the mortar 49 is solidified, the column base structure 41 described above is formed.

Also in this second embodiment, the mortar for supporting the base plate can be omitted by supporting the base plate 45 with the nut 53 and the intermediate removable nut 35 when the pillar 43 is constructed, so that the construction related to the mortar can be performed. The labor of supervision is reduced, and the mortar curing period is not required, so that the construction period can be shortened. Since the intermediate removable nut 35 can be removed after fixing the position of the pillar 43, the problem of durability as described above does not occur.

Subsequently, a third embodiment will be described. In the third embodiment, the base plate of the existing column base is widened and anchor bolts are added to reinforce the existing column base. In the third embodiment, an example will be described in which the column base structure 41 of the second embodiment is used as an existing column base and is reinforced. The configurations already described in the second embodiment will be omitted by adding the same reference numerals.

FIG. 15 is a view showing a reinforcing structure 71 in which the existing column base is reinforced by the method for reinforcing the existing column base according to the third embodiment, and FIG. 16 is a horizontal cross section along the line DD of FIG. .. The reinforcing structure 71 is a reinforcing structure in which the base plate 45 of the column 43 is widened by a base plate 75 (widening base plate) with a stiffener 73, and anchor bolts 81 are added.

The base plate 75 is joined to both sides of the base plate 45 with the pillar 43 in between. In the present embodiment, the base plate 75 is a substantially rectangular plate material, and its long side is welded to the side side of the base plate 45 by a welded portion 85. Through holes 77 are provided at both ends of the base plate 75 in the long side direction. Further, a mortar 79 is provided under the base plate 75.

Anchor bolts 81 are embedded in the foundation 42 in the vicinity of the pillar 43. The anchor bolt 81 is a post-installed anchor, and is installed in the same procedure as in the first embodiment. It should be noted that the holes formed in the foundation 42 when the anchor bolts 81 are installed and the solidifying material provided in the holes are not shown. For example, a threaded reinforcing bar or the like is used for the anchor bolt 81, and the structure is such that the reinforcing bar and the solidifying material are adhered to each other.

The anchor bolt 81 passes through the mortar 79 and is inserted into the through hole 77 of the base plate 75. The nut 83 is tightened from above the base plate 75 to the upper end of the anchor bolt 81 protruding from the through hole 77.

A stiffener 73 is provided on the base plate 75. The stiffener 73 is a substantially L-shaped plate material, and one end of the L-shape is joined to the central portion of the base plate 75 in the long side direction by welding or the like. The stiffener 73 is arranged along the short side direction of the base plate 75, and the other end of the L-shape is joined to the side surface of the pillar 43. The other end is welded to the side surface of the column 43 at the welded portion 87.

In this way, the base plate 45 of the pillar 43 is widened by the base plate 75 with the stiffener 73. The shape, arrangement, number, etc. of the base plate 75 are not particularly limited. For example, it is also possible to join the base plate 75 to each of the four sides of the base plate 45. Similarly, the shape, arrangement and number of stiffeners 73, arrangement and number of anchor bolts 81, and the like are not limited to the above examples. Further, a notch may be provided instead of the through hole 77.

Next, a method of reinforcing the existing column base according to the present embodiment will be described. In the present embodiment, first, as shown in FIG. 17, the anchor bolt 81 is installed in the vicinity of the pillar 43 in the same procedure as in the first embodiment. Then, an intermediate removable nut 35 is attached to the upper portion of the anchor bolt 81 protruding above the foundation 42 in the same manner as described above. In the present embodiment, the side side of the base plate 45 to be joined to the long side of the base plate 75 is chamfered diagonally in advance before welding as shown by a in the drawing.

Next, as shown in FIG. 18, the upper end of the anchor bolt 81 is inserted into the through hole 77 of the base plate 75, the base plate 75 is placed on the intermediate removable nut 35, and the anchor bolt 81 is placed on the base plate 75. The nut 83 is tightened to the upper end portion, and the base plate 75 is fixed to the anchor bolt 81 by the nut 83. As a result, the base plate 75 is supported by the nut 83 and the intermediate removable nut 35. As described above, the stiffener 73 is joined to the base plate 75. The long side of the base plate 75 to be joined to the side side of the base plate 45 is chamfered in advance for welding as shown by b in the drawing.

Then, as shown in FIG. 19, the long side of the base plate 75 is welded to the side side of the base plate 45 by the welded portion 85, and the stiffener 73 is welded to the side surface of the column 43 by the welded portion 87. As a result, the position of the base plate 75 is fixed, so the intermediate removable nut 35 is removed as shown in FIG. Then, the mortar 79 is filled between the base 42 and the base plate 75 as shown in FIG. When the mortar 79 is solidified, the reinforcing structure 71 described above is formed.

Also in this third embodiment, when the existing column base is reinforced by using the base plate 75, the mortar for supporting the base plate can be omitted by supporting the base plate 75 by the nut 83 and the intermediate removable nut 35. The labor of construction and supervision related to mortar is reduced, and the curing period of mortar is not required, so that the construction period can be shortened. Similar to the above, since the intermediate removable nut 35 can be removed after fixing the position of the base plate 75, the problem of durability as described above does not occur.

The present invention is not limited to the above embodiments. For example, as the intermediate removable nut 35, a nut member 35a in which two nut members 35a can rotate relative to each other is used, but the intermediate removable nut is not limited to this.

For example, the intermediate removable nut 65 shown in FIG. 21A is composed of a set of U-shaped nut members 65a and 65a, and a female screw 65c is provided in a semicircular recess 65b of each nut member 65a and 65a. It is formed. The intermediate removable nut 65 is arranged so as to sandwich the anchor bolt 31 (51, 81) between the nut members 65a, 65a as shown in FIG. 21 (b) from the side of the anchor bolt 31 (51, 81). Both ends thereof can be attached to the anchor bolts 31 (51, 81) by fixing them with the fixing portions 65d, and can be removed from the side of the anchor bolts 31 (51, 81) by releasing the fixing. In addition, as the intermediate removable nut, those having various shapes and mechanisms can be considered.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical scope of the present invention does not depend on the above-described embodiments. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the technical ideas described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

1, 71 ……… Reinforcement structure 2, 42 ……… Foundation 3 ……… Existing columns 5, 25, 45, 75 ……… Base plates 7, 27, 47, 77 ……… Through holes 9, 21, 49, 79 ……… Mortal 11, 31, 51, 81 ……… Anchor bolts 13, 33, 53, 83 ……… Nuts 23 ……… Reinforcing columns 29 ……… Splicing plate 30 ……… Hole 32 ……… Solidifying material 35, 65 ………… Intermediate removable nuts 35a, 65a ………… Nut members 35b, 65b ………… Recessed parts 35c, 65c ………… Female screw 41 ………… Column base structure 43 ………… Column 61 …… … Beam 65d ……… Fixed part 73 ……… Stiffener 85, 87 ……… Welded part

Claims (7)

It is a construction method of the column base,
Attach an intermediate removable nut to the anchor bolt embedded in the foundation,
A base plate with columns joined is placed on the intermediate removable nut, and
The base plate is fixed to the anchor bolt by a nut,
Fix the position of the pillar and
A method for constructing a column base, which comprises removing the intermediate removable nut and filling a mortar between the foundation and the base plate. The method for constructing a column base according to claim 1, wherein the intermediate removable nut has a U-shaped nut member and is removable from the side of the anchor bolt. It is a method of reinforcing existing column bases.
An intermediate removable nut is attached to the anchor bolt buried in the foundation near the existing column base.
A base plate to which reinforcing columns are joined is placed on the intermediate removable nut.
The base plate is fixed to the anchor bolt by a nut,
The reinforcing column is joined to the column of the existing column base,
A method for reinforcing an existing column base, which comprises removing the intermediate removable nut and filling a mortar between the foundation and the base plate. The method for reinforcing an existing column base according to claim 3, wherein the intermediate removable nut has a U-shaped nut member and is removable from the side of the anchor bolt. The base plate is fixed to the anchor bolt on the side far from the existing column base, and the side of the base plate close to the existing column base is arranged so as to wrap above the base plate of the existing column base. The method for reinforcing an existing column base according to claim 3 or 4. It is a method of reinforcing an existing column base having a base plate at the lower end.
An intermediate removable nut is attached to the anchor bolt buried in the foundation near the existing column base.
A widening base plate for widening the base plate is arranged on the intermediate removable nut.
The widening base plate is fixed to the anchor bolt by a nut.
The widening base plate is joined to the existing column base,
A method for reinforcing an existing column base, which comprises removing the intermediate removable nut and filling a mortar between the foundation and the widening base plate. The method for reinforcing an existing column base according to claim 6, wherein the intermediate detachable nut has a U-shaped nut member and is detachable from the side of the anchor bolt.

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