JPH04312658A - Fitting structure of post - Google Patents

Abstract

PURPOSE:To prevent a concrete foundation from generating cracks even when a bending moment generates on the post. CONSTITUTION:In a post-fitting structure fitting a post 4 wherein a base plate 5 having a bolt fitting part 7 at the periphery 6 is fixed in a concrete foundation in which an anchor bolt 2 is buried so as to expose the front end, a protrusion 8 is made almost in the middle of the lower face of the base plate 5. And the bolt fitting part 7 is fixed at the front end of the anchor bolt 2 in the condition that this protrusion 8 is placed at the upper face of the concrete foundation 1 and the peripherary 6 of the base plate 5 is relieved from the upper face of concrete foundation 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a column base mounting structure.

0002

[Prior Art] A conventional column pedestal mounting structure is shown in the figure. 50 is a concrete foundation, and anchor bolts 51 are buried so that their tips are exposed. 52 is a column base, and a base plate 53 is fixed to the lower end. To attach the column base 52 to the concrete foundation 50, place the base plate 53 on the upper surface of the concrete foundation 50 via non-shrinkage mortar 54, etc., and insert the anchor bolts 51 into the bolt installation holes provided at the peripheral edge of the base plate 53. It was fastened with a nut 55 through the tip.

0003

[Problem to be Solved by the Invention] In the above-mentioned conventional column base mounting structure, the entire surface of the base plate 53 is installed so as to be in contact with the concrete foundation 50 side, so the column base 52 tilts and a bending moment occurs. There was a problem in that cracks 56 occurred in the concrete foundation 50 corresponding to the peripheral edge of the base plate 53.

[0004] Accordingly, an object of the present invention is to provide a column pedestal mounting structure that can prevent cracks from occurring in a concrete foundation even if a bending moment occurs in the column pedestal.

[0005]

[Means for Solving the Problems] The column pedestal mounting structure of the present invention has a protrusion protruding from approximately the center of the lower surface of the base plate fixed to the lower end of the column pedestal, and this protrusion is mounted on the upper surface of the concrete foundation. The bolt attachment part provided on the peripheral edge of the base plate is fixed to the tip of the anchor bolt with the peripheral edge of the base plate floating above the upper surface of the concrete foundation.

[0006]

[Operation] Since the protrusion is provided approximately at the center of the lower surface of the base plate, a gap is formed between the peripheral edge of the base plate and the upper surface of the concrete foundation when the column base is placed on the concrete foundation. Therefore, the bending moment generated in the column base can be absorbed within this gap, and cracks can be prevented from occurring in the concrete foundation.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A column base mounting structure according to an embodiment of the present invention will be explained based on FIG. 1 is a concrete foundation, and several anchor bolts 2 and 3 are buried so that their tips are exposed. Reference numeral 4 denotes a steel tubular column base, and a base plate 5 is fixed to the lower end. The base plate 5 is formed to have a peripheral edge 6 protruding from the column base 4, and the peripheral edge 6 is provided with hole-shaped bolt attachment parts 7 through which the anchor bolts 2 can be inserted. A plate-shaped protrusion 8 is provided approximately at the center of the lower surface of the base plate 5, and a hole 9 through which the anchor 3 can be inserted is located at the axis of the column base 4. It is provided.

Next, the procedure for attaching the column base 4 will be explained. That is, the anchor 3 is inserted into the hole 9, and the protrusion 8 is placed on the upper surface of the concrete foundation 2 so that the bolt attachment part 7 corresponds to the anchor bolt 2. Then, nuts 10, 10 are attached to the anchor bolt 2 from both upper and lower sides of the base plate 5 so as to sandwich the bolt attachment portion 7, and bear the bending moment generated in the column base 4. In addition, by filling non-shrinkage mortar 11 or the like into the column base 4 through a small hole 12 formed on the side surface of the column base 4, the tip of the anchor 3 located inside the column base 4 is fixed, and the column base 4 is fixed to the base 4. bear such shearing forces. Note that a structure may be adopted in which non-shrinkage mortar or the like is provided on the upper surface of the concrete foundation 1.

In the column base mounting structure described above, a gap is formed between the peripheral edge 6 of the base plate 5 and the upper surface of the concrete foundation 1. Therefore, within this gap, the column base 4
It is possible to absorb the bending moment generated in the concrete foundation 1 and prevent cracks from occurring in the non-shrinkage mortar laid on the concrete foundation 1 and its upper surface. Also, base plate 5
By plastically deforming the protrusion 8 provided on the lower surface, performance with high deformability (high tenacity) is obtained, and seismic performance is improved.

Note that the protrusion 8 may be formed integrally with the base plate 5.

[0011]

Effects of the Invention According to the column pedestal mounting structure of the present invention, since the protrusion is provided approximately at the center of the lower surface of the base plate, when the column pedestal is placed on the concrete foundation, the periphery of the base plate and the concrete A gap is formed between the column and the top surface of the foundation, and within this gap, bending moments generated in the column base due to earthquakes, etc. can be absorbed. Therefore, it is possible to prevent cracks from occurring in the concrete foundation due to the peripheral edge of the base plate, and the seismic performance is improved.

[Brief explanation of drawings]

FIG. 1 is a sectional front view of a column pedestal mounting structure according to an embodiment of the present invention.

FIG. 2 is a cross-sectional front view of a conventional example.

[Explanation of symbols]

1 Concrete foundation 2 Anchor bolt 4 Pillar base 5 Base plate 6 Peripheral area 7 Bolt mounting part 8 Protrusion

Claims (1)

[Claims] Claim 1. A column pedestal mounting structure in which a column pedestal having a base plate fixed to its lower end and having a bolt attachment part on its periphery is attached to a concrete foundation in which an anchor bolt is buried so that the tip part is exposed, wherein the bottom surface of the base plate is A protrusion is provided at approximately the center of the base plate, and this protrusion is placed on the upper surface of the concrete foundation so that the peripheral edge of the base plate is lifted from the upper surface of the concrete foundation, and the bolt attachment portion is attached to the anchor bolt. A column base mounting structure characterized by being fixed to the tip of the column.