JP2018003499A - Construction method of base-isolation foundation structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple construction method of a base-isolation foundation structure.SOLUTION: A construction method of a base-isolation foundation structure comprises a process of arranging an anchor member on leveling concrete and arranging a lower end reinforcement, a process of arranging a column reinforcement in the anchor member, a process of arranging the upper end reinforcement and a base-isolation foundation reinforcement, a process of installing a lower side baseplate of a base-isolation device above the anchor member and fixing an anchor bolt and the anchor member provided by the lower side baseplate and a process of placing concrete in this order.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for constructing a base isolation structure.

  Seismic isolation structures that support buildings via seismic isolation devices are known. Seismic isolation devices are roughly classified into isolators made of sliding bearings, rolling bearings, laminated rubber, and the like, and dampers made of oil dampers, steel dampers, lead dampers, and the like. The seismic isolation device excluding the oil damper usually has a lower base plate and an upper base plate. The lower base plate is installed on a reinforced concrete foundation, and a structure is built on the upper base plate. The structure is built separately from the ground by a seismic isolation device, and suppresses damage in the event of an earthquake by transmitting the shaking of the ground during an earthquake to the structure above the upper base plate.

  In Patent Document 1, there is a seismic isolation base on the floor slab, the lower flange plate of the base isolation device is installed on the base isolation base, and the stud anchor of the lower flange plate is embedded in the base isolation base. A seismic structure has been proposed. The reinforcing bars for constructing the seismic isolation foundation are arranged so that the position of the anchor is marked on the floor slab and does not interfere with the anchor position.

  Here, in a large structure, in order to firmly fix the lower base plate, the length of the anchor bolt for fixing the lower base plate may reach 1 m or more. When the anchor bolt becomes long, it is necessary to perform marking for positioning not on the foundation beam but on the concrete. In a large structure, the length of the beam may be 2 m or more, and it is difficult to arrange the bars so that they do not interfere visually with the mark marked below 2 m. Further, when the reinforcing bar and the anchor bolt interfere with each other, the reinforcing bar has to be shifted after the bar arrangement, which is very troublesome.

JP 2011-12464 A

  An object of the present invention is to provide a simple construction method for a base-isolated base structure.

1. A process of placing the anchor member on the discarded concrete and arranging the bottom reinforcement,
A step of arranging a column reinforcement in the anchor member;
The process of arranging the upper end muscle and the base isolation base,
Installing a lower base plate of the seismic isolation device above the anchor member, and fixing the anchor bolt and the anchor member provided in the lower base plate;
The process of placing concrete,
A method for constructing a base-isolated base structure characterized by comprising
2. The anchor bolt and the anchor member are fixed below the upper end muscle. Of building seismic isolation foundations as described in 1.
3. The anchor bolt and the anchor member are fixed by welding. Or 2. Of building seismic isolation foundations as described in 1.
4). The anchor member includes a height adjustment jig that adjusts and supports the height of the lower base plate. ~ 3. The construction method of the base isolation structure described in any of the above.

In the present invention, an anchor member is disposed on abandoned concrete, and the anchor member can be used as an anchor of the lower base plate by fixing the anchor member and an anchor bolt included in the lower base plate of the seismic isolation device. . As long as the anchor bolt has a length that can be connected to the anchor member, it is possible to shorten the length of the anchor bolt, and greatly simplify the bar arrangement work that takes into account interference with the anchor bolt. Because it is possible, it is excellent in workability, and the short construction period and the construction cost can be reduced.
Since the anchor member is firmly fixed by the column reinforcement, when the ready-mixed concrete is placed, the anchor member is not pressed and moved. Since the anchor member fixed at the correct position and the anchor bolt of the lower base plate are fixed, the lower base plate can be installed at the correct position.
By fixing the anchor bolt and the anchor member below the upper end muscle, it is possible to firmly fix the anchor base and the lower base plate. The anchor member and anchor bolt are fixed below the upper bar, but because it is directly under the upper bar, it is not necessary to dive under the reinforcing bar, and it can be constructed by extending the hand from the top. Excellent.
By providing the anchor member with a height adjustment mechanism that corrects the inclination of the lower base plate, the lower base plate can be installed horizontally, and the seismic isolation device can be installed as designed.

The figure explaining the process of the construction method of the base isolation structure of this invention. The figure which shows the example which arranged the lower end reinforcement in the state which has arrange | positioned the anchor member. The figure explaining the process of the construction method of the base isolation structure of this invention. The figure which shows the example which arranged the column reinforcement to the anchor member. The figure explaining the process of the construction method of the base isolation structure of this invention. The figure explaining the process of the construction method of the base isolation structure of this invention. The figure which shows the state which mounted the lower side baseplate on the seismic isolation basic muscle. The figure explaining the process of the construction method of the base isolation structure of this invention.

The present invention is a step of arranging an anchor member on abandoned concrete and arranging a lower end reinforcement,
A step of arranging a column reinforcement in the anchor member;
The process of arranging the upper end muscle and the base isolation base,
Installing a lower base plate of the seismic isolation device above the anchor member, and fixing the anchor bolt and the anchor member provided in the lower base plate;
The process of placing concrete,
It is related with the construction method of the seismic isolation base structure which has in this order.

Hereinafter, the construction method of the base isolation structure of this invention is demonstrated in order of a process.
“The process of placing the anchor member and placing the bottom bar on the discarded concrete”
The anchor member 1 is arranged on the discarded concrete G provided on the bottom surface of the foundation, and the lower end reinforcement 2 is arranged (FIGS. 1 and 2).
The anchor member 1 includes a base member 11 fixed on the discarded concrete G, a plurality of vertical members 12 erected from the base member, a horizontal member 13 extending horizontally by connecting the tops of the vertical members, A brace 14 that connects the vertical members and extends obliquely is provided. The base member 11, the vertical member 12, the horizontal member 13, and the brace 14 are made of angle steel.
The lower end reinforcement 2 is arranged above the base member 11 of the anchor member. The anchor member 1 can be kept horizontal by arranging the lower end bars above the base member of the anchor member.

"Process to arrange column reinforcement in the anchor member"
Column bars are arranged around the anchor member (FIGS. 3 and 4). In the figure shown in FIG. 4, in addition to the column bars, a pedestal that supports the scaffolding plate is provided at an intermediate height portion between the bottom and top reinforced bars, and the scaffold is placed on the pedestal.
The anchor member 1 is arranged with the column reinforcement 3 connected to the lower end reinforcement 2, so that the pressure of the flowing concrete when a person or an object comes in contact with the surrounding construction or when placing the ready-mixed concrete is applied. Even if added, it is firmly fixed to the designed part so that it does not move or tilt. Further, by arranging the column bars 3, the anchor member 1 can be prevented from being tilted or shaken, and the accuracy in the vertical direction can be kept high.

"The process of arranging the top and base isolation bases"
The upper end muscles and seismic isolation basic muscles, and other footing muscles (not shown) are arranged as required (FIG. 5).
The upper reinforcement 4 and the seismic isolation basic reinforcement 5 are arranged so as not to interfere with the anchor bolts provided in the lower base plate to be installed thereafter. The base isolation reinforcement 5 means a horizontal reinforcing bar arranged in the base isolation base 50 in FIG. 8 and a shear reinforcing reinforcement arranged in a direction orthogonal to the horizontal reinforcement.
A method for arranging the upper end reinforcement 4 and the seismic isolation basic reinforcement 5 at a position where they do not interfere with the anchor bolt is not particularly limited. However, a guide reinforcement indicating the position of the anchor bolt is provided on the horizontal member of the anchor member, and this guide reinforcement is provided. Can be used to determine the position of the upper and lower base muscles. Since the horizontal member is located immediately below the upper end reinforcement, it can be accurately arranged as compared with the ink marking on the discarded concrete.

“A step of installing a lower base plate of the seismic isolation device above the anchor member and fixing the anchor bolt and the anchor member included in the lower base plate”
The lower base plate 6 is placed on the seismic isolation basic muscle 5, and the anchor bolt 61 and the anchor member 1 are fixed (FIGS. 6 and 7).
In the previous step, the upper reinforcement 4 and the seismic isolation basic reinforcement 5 are arranged so as not to interfere with the anchor bolt 61 provided in the lower base plate 6, so that the lower base plate 6 can be easily placed at a predetermined location. Can be placed. Further, it is sufficient that the anchor bolt 61 has a length that reaches the horizontal member 13 of the anchor member 1, and a long anchor bolt that extends to the vicinity of the lower end muscle 2 is not necessary. Since the lower base plate 6 used in the present invention has a short anchor bolt 61, it is lighter and smaller than a conventional base plate having a long anchor bolt. Therefore, the lower base plate 6 used in the present invention can be transported by a worker's hand and placed at a predetermined position without being lifted by a heavy machine.

Next, the anchor bolt 61 and the anchor member 1 are fixed. A method for fixing the anchor bolt 61 and the anchor member 1 is not particularly limited, and welding, a bolt and a nut, a clamp, or the like can be used. Among these, fixing by welding is preferable because the anchor bolt 61 can be firmly fixed to the anchor member 1. Further, this fixing work is performed directly below the upper end muscle 4. Therefore, it is possible to work by extending the hand from the gap between the upper end muscles 4, and it is not necessary to dig into the lower end muscles 4 and work is excellent.
Further, before fixing the anchor bolt 61 and the anchor member 1, the inclination of the lower base plate 6 is adjusted by a height adjusting jig (not shown) and placed so as to be horizontal. Although the height adjustment jig is not particularly limited, for example, a height adjustment jig including a rod-shaped support portion provided with a level adjustment screw can be given. The height adjusting jig is installed at the four corners of the lower base plate or the anchor member.

“Process of placing concrete”
The concrete that constitutes the base for seismic isolation is placed (Fig. 8).
The seismic isolation base includes a base 10 and a base isolation 50 that protrudes from the upper surface of the base. Concrete can be placed by a known method.

G Abandoned concrete

1 Anchor member 11 Base member 12 Vertical member 13 Horizontal member 14 Brace

2 Lower bar 3 Column bar 4 Upper bar 5 Base-isolated base

6 Lower base plate 61 Anchor bolt

10 Foundation part 50 Base isolation part

Claims (4)

A process of placing the anchor member on the discarded concrete and arranging the bottom reinforcement,
A step of arranging a column reinforcement in the anchor member;
The process of arranging the upper end muscle and the base isolation base,
Installing a lower base plate of the seismic isolation device above the anchor member, and fixing the anchor bolt and the anchor member provided in the lower base plate;
The process of placing concrete,
A method for constructing a base-isolated base structure characterized by comprising   The said anchor bolt and the said anchor member are fixed below the said upper end reinforcement, The construction method of the base isolation structure of Claim 1 characterized by the above-mentioned.   The said anchor bolt and the said anchor member are fixed by welding, The construction method of the base isolation structure of Claim 1 or 2 characterized by the above-mentioned.   The said anchor member is equipped with the height adjustment jig which adjusts and supports the height of the said lower side baseplate, The construction method of the seismic isolation base structure in any one of Claims 1-3 characterized by the above-mentioned.