JP3798102B2 - Column base structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a column base structure used for a column base of a steel frame or a steel reinforced concrete structure .
[0002]
[Prior art]
Conventionally, as a method of fixing a steel column to foundation concrete, a column base is fixed to the lower end of the column, and this column base is inserted into an anchor bolt in which the lower end is embedded in the basic concrete in advance, and is fixed with a nut. The method is often taken. In the case of this method, before fixing with a nut, once it is installed with a gap between the foundation concrete and the column base metal, and also between the anchor bolt and the column base metal, the mortar is securely inserted into the gap after tightening the nut. If the grout is not packed, if a bending moment or shearing force is applied to the column base, rotational deformation or horizontal movement more than expected may occur and the stability of the entire building may be impaired. In order to prevent this, for example, as in Japanese Patent Publication No. 5-63585, a special washer is used to simultaneously fill the gap generated in the column base with a grout material to ensure that the column base is integrated integrally. A fixing method has been devised.
[0003]
[Problems to be solved by the invention]
Special washer 10 of pedestal shown in JP-A Kokoku 5-63585 shows a state in use in FIG. 11, a perspective view from the upper side in FIG. 12 shows a perspective view from the back side in FIG. 10 As described above, a recess 11 for grouting is provided on the back surface side, and a through hole 12 for grouting or venting is provided. Thus, when filling the grout material 7, the grout material 7 is press-fitted from the through hole 12 of one washer 10, and the injection state is confirmed by leakage of the grout material from the other washer through hole. .
[0004]
In such a conventional column base structure, the grout material 7 flowing in from the through hole 12 of the washer 10 once hits the upper surface of the column base metal 1 and flows laterally to the column from the gap between the bolt hole 3 and the anchor bolt 2. It will enter the lower surface side of the leg hardware 1. The grout material has the property that the fluidity decreases with time. In the conventional filling method, even if the inflow speed from the through-hole 12 is increased, the inflow speed is reduced at the time of lateral movement or wrapping around the space between the bolt holes through the upper surface of the column base metal, and the column base having a large planar size is obtained. In the case of hardware, it takes time to fill in the gaps on the bottom surface of the column base metal, and there is a risk that it will be difficult to confirm filling from one place and leakage from other through holes due to a decrease in fluidity of the grout material. In order to avoid this, there is a problem that the pressure for filling the grout material must be increased and the weir plate 9 must be strengthened.
[0005]
In addition, when a force or a bending stress is applied to pull up the column A due to an earthquake or the like, the nut 5 attached to the upper portion of the anchor bolt 2 presses the column base 1 through the washer against the lifting force. Resist at. In this case, the washer receives a compressive force from the contact surface of the nut 5 on the upper surface. When the acting load is low, the grout material 7 packed in the washer recess also resists against the upper surface of the column base metal 1 and suppresses the lifting of the column base metal, but the grout material 7 in that portion has undergone compression failure. After that, the resistance is in the shape of a gate-shaped hardware having the recess 11 as a gap. At this time, since the concave portion 11 has a shape including the bolt hole 3 in a wide range, a large bending moment is applied to the plate portion on the upper surface of the special washer 10, so that the plate on the upper surface of the special washer 10 must be thickened.
[0006]
Furthermore, in addition to the thickness of the plate portion above the washer, a thickness for providing the recess 11 is required, the total thickness of the special washer 10 is increased, and from the upper surface of the column base 1 to the upper end of the anchor bolt 2. The height of the floor becomes higher, the amount of concrete on the floor becomes larger, and workability deteriorates. Japanese Patent Application Laid-Open No. 07-102039 discloses a column base metal that is connected to a bolt hole and is provided with a mortar injection hole and a mortar filling detection hole that are open on the upper surface. The injection hole is a thin hole similar to the filling detection hole, and it is difficult to reliably fill the inside with mortar having a property that the fluidity rapidly decreases with time from the filling hole.
[0007]
[Means for Solving the Problems]
The present invention has been made to solve the above problems.
[0008]
That is, the present invention provides a column base structure in which a column base metal fixed to a lower part of a column material is fixed by an anchor bolt embedded in the lower part of the foundation concrete, and the shape of the bolt hole of the column base metal is an upper surface. When viewed from the side, it is enlarged in the outer direction or the circumferential direction of the column base metal, and when viewed from the cross section, the wall surface of the bolt hole is composed of an inclined surface whose diameter decreases from the upper surface end toward the lower surface end, The upper part of the anchor bolt is inserted into the bolt hole of the column base metal and the bolt hole of the washer, the nut is screwed together, the gap between the upper surface of the foundation concrete and the lower surface of the column base metal, and the bolt hole and anchor bolt of the column base metal The column base structure is characterized in that a grout material is filled in the gap between the base concrete and the base metal fittings.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In the column base metal used in the column base structure of the present invention , the peripheral wall of the bolt hole is an inclined surface in which the wall diameter of the bolt hole gradually decreases from the upper surface end toward the lower surface end when viewed from the cross section of the column base metal. That is, a taper is provided . In this way, when the grout material is tapered on the peripheral wall of the bolt hole in the direction in which the grout material flows into the center of the column base metal, the grout material flows into the periphery of the bolt hole and the center of the column base metal more smoothly, and the grout The workability of material filling can be further improved.
[0010]
Of course, unless it departs from the spirit of the present invention that exhibits the specific effects of the present invention, an inclined surface is provided in the lower portion of the vertical wall surface of the bolt hole, or the tapered surface (inclined surface) of the bolt hole is cut off. A vertical portion may be provided. Further, in the outer peripheral direction of the column base metal or in the peripheral direction of the bolt hole in the peripheral direction, a mark or mark indicating the center position of the anchor bolt inserted through the hole or an anchor on the peripheral edge of the bolt hole. It is also possible to provide a notch, a slit, a protrusion, or the like that serves as a guide indicating the center position of the bolt.
[0011]
The bolt hole must be larger than the diameter of the anchor bolt in all parts so that grout material can be injected into the lower part of the column base metal by this bolt hole part, but if this bolt hole is circular, the anchor bolt The normal position of can be determined as the center position of the circle, and anchor bolts can be inserted according to the amount of scale, but when inserting the anchor bolt, if the enlarged shape of the bolt hole is elliptical, for example, the normal position of the anchor bolt Tends to be unknown. However, if there is a mark or the like indicating the normal center position of the anchor bolt as described above, it becomes a guideline for insertion, and a more preferable effect can be given in construction.
[0012]
The bolt holes of the column base metal can be formed by cutting, fusing, or pressing, and can be integrally manufactured by casting or forging. In addition, a mark or the like serving as a position guide for the anchor bolt around the bolt hole can be formed in the same manner. Furthermore, a protrusion protruding on the lower surface of the washer, for example, a downward protrusion generated by pressing the grout distribution hole, or a protrusion around the grout distribution hole is provided to prevent rotation beyond the allowable range of the washer. If the restraining mechanism is provided, it is possible to prevent a risk that the washer rotates due to the rotation of the nut grounded on the top surface of the washer, and the grout distribution hole of the washer is detached from the bolt hole and obstructs the distribution of the grout material.
[0013]
【Example】
Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 7 show a first embodiment. 1 and 2 are an overall schematic side view and a schematic plan view of a first embodiment of the column base structure of the present invention. FIG. 3 shows a cross section of the main part, and FIGS. 4 and 5 show a plane and a cross section of the column base metal of the present invention. 6 and 7 are perspective views of the column base hardware. In these figures, the column base hardware has the same structure. As shown in the plan view of FIG. 4 and the cross-sectional view of FIG. 5, the column base 1 shown in this embodiment is fixed to the lower end of the column A, and is a bolt inserted through the upper portion of the anchor bolt 2. There is a hole 3, and the bolt hole 3 has its planar shape expanded in a plan view outwardly from the column base 1, and the periphery of the bolt hole 3 of the column base 1 on the side of the hole expansion is a column. A tapered surface (that is, an inclined surface) 6 is provided from the upper surface to the lower surface of the leg metal object.
[0014]
The column base 1 may have a structure that can be manufactured from a flat steel plate as shown in FIG. 6, or a form that can be manufactured by casting or forging as shown in FIG. In this way, in order to form the bolt hole 3 having the hole expanded outwardly or circumferentially, a die is prepared in advance in the case of casting, forging, in addition to cutting, fusing, and pressing. It can also be manufactured. When installing the above-mentioned column base 1 fixed to the lower end of the column A on the foundation concrete B, the level adjusting material 8 is placed as a spacer on a required position on the upper surface of the foundation concrete B, and the column base is mounted thereon. 1 is installed, and the upper part of the anchor bolt 2 in which the lower part is embedded in the concrete of the basic concrete B is inserted into the bolt hole 3 and the bolt hole 4a of the washer 4 which are larger than the bolt diameter of the column base 1 The nut 5 is screwed and tightened.
[0015]
The washer 4 has a flat plate shape. In this embodiment, as shown in FIGS. 2 and 3, etc., a grout distribution hole or an air vent hole 4b that opens to a planar enlarged portion of the bolt hole is formed. It is installed so as to include the hole 3 in a plane. In filling the grout material 7, as shown in FIG. 1, a weir plate 9 installed on the upper surface of the foundation concrete B is provided around the column base 1, and the grout material 7 is provided from the grout circulation hole 4 b of one washer 4. And the grout material 7 is inserted into the gap between the upper surface of the foundation concrete B and the bottom of the column base 1 and the gap between the bolt hole 3 and the anchor bolt 2 of the column base 1 using the enlarged portion of the bolt hole 3 as a flow passage. It is filled and the column base is fixed integrally. In filling the grout material 7, the grout material 7 injected from the grout circulation hole 4 b of the washer 4 flows into the lower periphery of the bolt hole 3 and the center of the column base metal through the tapered surface 6. Compared with the case where the grout material 7 is injected vertically, the filling of the bottom surface of the column base 1 is further improved.
[0016]
Since the present embodiment is formed as described above, the grout material can be filled smoothly and in a short time, and the column base metal 1 can be mounted even on a column base metal having a large planar size as shown in FIGS. The grout material 7 can be surely filled in the gap generated when installed on the foundation concrete B, and the column base can be fixed integrally. On the other hand, the washer 4 can be a simple washer with a flat plate shape, and the contact area to the upper surface of the column base 1 can be made larger than before, so that the stress load on the washer 4 can be reduced, so that the plate thickness is thin. It can be. Furthermore, since the height from the upper surface of the column base 1 to the upper end of the anchor bolt 2 can be reduced because the washer 4 is thin, it is easy to prevent the anchor bolt from protruding from the finished surface of the floor.
[0017]
In this embodiment, the column A is a square steel pipe. However, a similar column base hardware and column base structure can be used for a circular steel pipe, a H-shaped steel, or a cross-shaped column combining steel materials. Moreover, although the case where the number of anchor bolts was four was shown in the present Example, even when the number of anchor bolts exceeds four, it can be set as the same column base metal and column base structure. The example of the planar shape of the column base metal object in the case of eight anchor bolts is shown to Fig.8 (a) and (b). 8A and 8B, the planar shape of the bolt hole 3 is expanded in a plan view in the outer peripheral direction or the peripheral direction of the column base 1.
[0018]
[0019]
Next, another embodiment of the planar shape of the bolt holes 3 in FIG. FIG. 9 is a plan view of an essential part showing the upper plane shape of the bolt hole 3 of the present invention and also showing the relationship with the anchor bolt 2 inserted through the hole.
[0020]
The conventional bolt hole is the same as the cross-sectional shape of the anchor bolt, and is usually a circular bolt hole shape . On the other hand, FIG. It is. Thus, not only in the shape of an egg, but also when a part of the outer periphery of the bolt hole 3, preferably about a half of the outer periphery is gently expanded in a plane, the area of the grout circulation hole 4 b of the washer 4 In addition, the area of the enlarged portion can be made relatively large, and even if the position of the grout circulation hole 4b is shifted due to the horizontal movement of the washer 4, there is an advantage that the filling property of the grout material 7 can be secured satisfactorily. On the other hand, (b) is provided with a projection as a planar shape of the bolt hole 3 on a part of the periphery of a perfect circular bolt hole, and the hole is enlarged. (C) is a projection similar to (b) By increasing the number, it is possible to increase the number of selected branches of the enlarged hole portion selected as the grout material 7 flow passage. In addition, the shape of the bolt hole 3 is not a problem even if these shapes are combined or the outer shape curve is changed to a straight line.
[0021]
In any of the embodiments shown in FIG. 9, the bolt hole 3 itself is provided with a hole expanding portion that serves as a flow passage for the grout 7 in a limited direction. In this case, the contact area between the back surface of the washer 4 and the top surface of the column base 1 can be increased compared to the conventional case, and the washer 4 can be made small. The direction of the hole expansion is, for example, when the column shape is a cross and the distance between the bolt hole 3 and the column is large, considering the workability, either direction may be used, but a square steel pipe or a circular steel pipe is used as the column. In this case, when the distance between the anchor bolt 2 and the column A is short, considering the filling workability of the grout material 7, it is preferable to set the column base metal 1 in the outer direction or the circumferential direction rather than the column A side. In addition, since the expansion of the bolt hole 3 tends to lead to a cross-sectional defect of the column base 1, when trying to ensure the strength and rigidity of the column base, normally avoid the column side where the bending moment is large and avoid the column side bracket. It is preferable to enlarge the hole to the outer peripheral side of 1.
[0022]
Further, 3a in FIG. 9A is an example of a stamp indicating the normal center position of the anchor bolt 2. When the hole is enlarged in one direction as in (a), it is sufficient to provide at least three marks whose extension lines are orthogonal. Although marks can be similarly applied to (b) and (c), the center position of the anchor bolt 2 can also be indicated by making the extension lines of the projections orthogonal as shown in (c).
[0023]
In the flat washer 4 used for the column base structure of the present invention, the grout distribution hole 4b of the washer 4 installed on the upper surface of the bolt hole 3 is a grout material as illustrated in FIG. 7 must be opened to the bolt hole side in order to check the filling condition by injecting air 7 and removing air and further leaking grout material 7. When the nut 5 placed on the upper surface of the washer 4 is rotated to fasten the column base 1 to the concrete, the grout distribution hole 4b may come off from the bolt hole 3 because the washer 4 rotates together with the nut 5. If present, a protrusion protruding toward the bolt hole 3 on the lower surface of the washer 4, for example, a downward protrusion generated by pressing the grout distribution hole 4 b, or a separately provided protrusion is used for the grout distribution hole of the washer 4. 4b may not be removed from the bolt hole 3 in a plan view. However, when the enlarged portion of the bolt hole 3 exists outside the washer, the enlarged portion outside the washer serves as an opening, even if the washer is not provided with a grout circulation hole.
[0024]
【The invention's effect】
The column base hardware used in the column base structure of the present invention has a bolt hole shape that is expanded outward or circumferentially of the column base metal when viewed from the top side, and the wall surface of the bolt hole when viewed from a cross section. Since it has an inclined surface with a hole diameter decreasing from the upper surface end toward the lower surface end, it is possible to securely fill the grout material in the gap generated when the column base hardware is installed on the foundation concrete and to fix the column base portion integrally. At the same time, the part where the bolt holes of the column base hardware are expanded outward or in the circumferential direction of the column base hardware becomes a grout flow passage through which the grout can be circulated directly from the top surface to the bottom surface of the column base metal. It can flow directly into the gap on the underside of the column base, once it does not stay on the top of the leg metal, it can be filled with grout material smoothly and in a short time even with a relatively large column base metal, and the inflow pressure is small. Already .
[0025]
In addition , the washer can have a simple flat cross-sectional shape, and the contact area of the washer to the top surface of the column base metal can be made larger than before, so that the stress load on the washer can be reduced, so the washer is a thin plate. It can be thick. Furthermore, since the height from the top of the column base metal to the upper end of the anchor bolt can be reduced by reducing the thickness of the washer, the protrusion of the anchor bolt from the finished surface of the floor can be reduced. Furthermore, since the shape of the washer is simple, manufacturing, transportation, and inventory management are easy, and costs can be reduced overall. In addition, a stamp or mark indicating the center position of the anchor bolt inserted through the hole or an anchor at the periphery of the bolt hole at the peripheral part of the top surface of the bolt hole in which the planar shape of the hole is expanded in the outer peripheral direction or the peripheral direction of the column base metal By providing a notch, a slit, a protrusion, or the like that serves as a guide indicating the center position of the bolt, it can be used as a guide when inserting the anchor bolt.
[0026]
Furthermore, a protrusion protruding toward the bolt hole side on the lower surface of the washer, for example, a downward protrusion generated by pressing the grout distribution hole, or a protrusion around the grout distribution hole is provided, which is more than necessary for the washer. If a rotation restraining mechanism is provided, it is possible to prevent the risk that the washer rotates due to the rotation of the nut grounded on the top surface of the washer and the grout distribution hole of the washer is detached from the bolt hole and obstructs the distribution of the grout material. In addition, the column base structure of the present invention is capable of securely filling the grout material in the gap generated when the column base metal is installed on the foundation concrete and fixing the column base unit integrally. Further, since the grout material can be filled in a short time, the column base can be integrally fixed even with a column base metal having a large planar size.
[Brief description of the drawings]
FIG. 1 is a schematic side view showing an example of a column base structure of the present invention.
FIG. 2 is a schematic plan view of FIG.
3 is a cross-sectional view of the main part of FIG.
FIG. 4 is a plan view of an example of a column base hardware having a column base structure according to the present invention.
5 is a cross-sectional view of the column base metal of FIG. 4 along AA ′. FIG.
6 is a perspective view of the column base hardware of FIG. 4; FIG.
FIG. 7 is a perspective view of a column base hardware having a column base structure according to the present invention.
FIG. 8 is a plan view of another embodiment of the column base hardware of the column base structure of the present invention.
FIG. 9 is a plan view of an essential part showing another embodiment of the bolt hole of the column base metal of the column base structure of the present invention.
FIG. 10 is a perspective view of the lower surface side of a conventional special washer.
FIG. 11 is a cross-sectional view of a main part showing a conventional column base structure.
FIG. 12 is a top perspective view of a conventional special washer.
[Explanation of symbols]
A Column B Foundation concrete 1 Column base 2 Anchor bolt 3 Bolt hole 3a Mark 4 Washer 4a Bolt hole 4b Hole 5 Nut 6 Tapered surface 7 Grout material 8 Level adjusting material 9 Weir plate 10 Special washer 11 Recess 12 Through hole

Claims (1)

In a column base structure in which a column base hardware fixed to the lower part of the column material is fixed by anchor bolts embedded in the lower part of the foundation concrete, the shape of the bolt hole of the column base hardware is viewed from the top side. The wall surface of the bolt hole is enlarged in the outer direction or the circumferential direction of the hardware, and the wall surface of the bolt hole is an inclined surface whose diameter decreases from the upper surface end toward the lower surface end when viewed from the cross section. The upper part of the anchor bolt is inserted into the bolt hole of the washer and the nut is screwed, and the grout material is inserted into the gap between the upper surface of the foundation concrete and the lower surface of the column base metal and the gap between the bolt hole of the column base metal and the anchor bolt. The column base structure is characterized in that the foundation concrete and the column base hardware are integrally fixed by filling

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