JPH0411118A - Erecting of pc column on foundation - Google Patents

Abstract

PURPOSE:To carry out the work safely and easily by horizontally arranging a foundation side board plate on the bottom surface of a recessed groove of the upper surface of the foundation, so as to insert a PC column in the recessed groove, and by stretching and fixing an anchor steel rod on a brattice part, so as to self-stand the PC column. CONSTITUTION:A concrete foundation 21 is built on the upper end of a foundation pile 23 in an integrated manner, and a recessed part 24 is molded on the upper surface thereof. A foundation side board plate 25 is fixed on the bottom surface of the recessed groove 24. An anchor steel rod 26 is inserted in an anchor steel rod inserting hole 29, while the lower end of a PC column 22 is dropped in the recessed groove 24, so as to connect the board plates 25, 30 with each other. A fixing plate and a nut 31 are fitted with each other, and are stretched and fixed on the upper end of the anchor steel rod 26. After the PC column 22 is thus self-stood, a site concrete 32 is placed in the gap in the recessed groove 24, and a brattice part 28 of the lower end of the PC column 22 is buried in the foundation 21.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a method for installing precast concrete columns (hereinafter referred to as PC columns) on a foundation when constructing a multi-story structure.
Regarding the C-pillar erection method.

(Prior art) Generally, when constructing a multi-story structure such as a building using PC columns, a PC column with a height of about three stories is manufactured in advance and then erected on a concrete foundation cast on site. I try to do that. As shown in Fig. 3, the conventional method of erection is to open a column insertion hole 2 on the top surface of a concrete foundation 1, place the PCC 50 upright in the hole and drop it into the hole, and use support wires 4 on all sides to maintain verticality. After the adjustment, a wedge 5 is driven into the opening of the column fitting hole 2 to temporarily secure it, and then a filler material 6 such as cement mortar or concrete is filled into the gap in the column fitting recess 2, and this is solidified. by P
We are trying to integrate it with CC50 Basic 1. In this case, if the depth of the pillar insertion hole 2 is 1.5 times or more the diameter of the PCC 50, a rigid connection is achieved.

In addition, as shown in FIG. 4, one end of the PC steel bar 10 is buried and fixed in the cast-in-place concrete foundation 1, and the other end is made to protrude above the foundation 1. Insert it in the longitudinal direction and connect the lower end to PCC5
This PCC is made to protrude into the recessed part 12 on the lower end surface.
The verticality is adjusted by the supporting wire 4 on the upper surface of the foundation 1 via the 50-bed mortar 13, and the PC steel rods 10 and 11 of the foundation 1 and the PC pillar 3 are connected with the coupler 14 in the recessed part 12, There is a method in which the PC steel rod 11 is fixed under tension at the upper end of the PCC 50, and made to stand on its own while introducing prestress in the tightening direction of the PCC 50, and the recessed part 12 is filled with post-molded mortar.

(Problem to be solved by the invention!) In all of the above-mentioned conventional methods, the verticality of the PC pillar is adjusted by adjusting the length of the surrounding support wire. However, the heavier the PC pillar becomes, the more difficult it becomes to adjust its verticality, and the longer it takes for it to stand on its own, during which time a long support wire is strung diagonally around the PC pillar. There will be
There was a problem in that it interfered with other tasks, resulting in poor work efficiency.

In addition, with the above-mentioned method of providing a column insertion hole in the foundation, it is necessary to increase the strength of the foundation concrete around the hole, but since it is cast on site, it is difficult to manage it to develop strength. Moreover, since the hole for inserting the pillar is deep, it is difficult to accurately level the bottom of the hole.

Furthermore, in the method of making it self-supporting using the PCa rod mentioned above,
At the site, tension work is required at the top end of the long PC column before it becomes self-supporting, which is highly dangerous, and there is a recess at the bottom end of the PC column for the work space for connecting the PC steel bars.
Either this would result in a cross-sectional defect in the column, and to compensate for this, the entire column would need to be made thicker.

The present invention has been made to solve various problems of the conventional methods as described above.

(Means for Achieving Section U) The gist of the present invention for solving the conventional problems as described above is to have an overhanging portion integrally on the outer circumferential surface of the lower end, and to A precast concrete column (hereinafter referred to as a PC column) is used, which has an anchor steel rod insertion hole opened through it and a column-side pedestal plate perpendicular to the column axis fixed to the bottom surface, and the PC column supports When constructing a concrete foundation, a recess into which the lower end of the PC column will be inserted is formed on the upper surface of the foundation, and the top of the anchor steel rod for fixing the PC column is inserted from the bottom of the recess. At the same time, a foundation side pedestal plate with a flat upper surface is fixed horizontally to the bottom of the recess, the PC column is erected and inserted into the recess, and the anchor steel rod is inserted into the recess. the two pedestal plates are joined to each other by being inserted into the insertion hole;
An anchor steel rod is fixed under tension on the overhanging part to make the PC column independent, and then cast-in-place concrete is poured into the recessed part to embed the lower end of the PC column in the concrete foundation. The method of installing PC pillars is as follows.

(Function) In the method of the present invention, if the horizontality of the foundation-side pedestal plate fixed to the bottom of the recessed portion is adjusted accurately in advance, the PC column can be installed by superimposing the column-side pedestal plate on the top surface of the foundation-side pedestal plate. The columns are erected vertically. By tension-fixing the anchor steel rod that has passed through the overhang in this state,
Stands on its own without any support from a PC pillar or anything else. Even after the lower end of the PC column is filled with cast-in-place concrete, the external force in the horizontal direction applied to the PC column is received by the anchor steel rod, and no shear force is applied to the foundation concrete around the depression.

(Example) Next, an example of implementation of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 shows a structure in which PC columns are erected on a foundation constructed according to the present invention.

In the figure, 21 is a concrete foundation, and 22 is a PC
It is a pillar. The concrete foundation 21 is constructed integrally with the upper end of the foundation pile 23, and a recessed part 24 for installing the column surface is formed on the upper surface of the concrete foundation 21. A base-side pedestal plate 25 made of steel is fixed to the bottom surface of the recessed portion 24. The pedestal plate 25 has a flat upper surface, and an anchor stud bolt 25a protrudes from the lower surface, which is buried in the foundation concrete.

A plurality of anchor steel rods 26 are provided protruding from the bottom surface of the concave portion 24 . This anchor steel rod 26 has a fixing fitting 27 at its lower end.
is fixed and embedded in the foundation concrete, and projects upward through the pedestal plate 25 on the upper end side.

The PC columns 22 are formed in advance in a concrete column manufacturing yard such as a factory, and are used to have a length of 1 to 3 floors, if necessary.

A pair of overhanging portions 28 are integrally molded on both sides of the lower end of the PC column 22 and are arranged opposite each other, and an anchor steel rod insertion hole 29 is opened through the overhanging portions 28 in the direction of the column axis. . Further, a column-side pedestal plate 30 made of a steel plate is fixed to the bottom surface of the PC column 22 at right angles to the column axis. This pedestal plate 30 has a flat bottom surface, and has an anchor stud bolt 30a protruding from the top surface, and the stud bolt 30a is embedded and fixed in the column.

The PC column 22 is erected by inserting the anchor steel rod 26 into the anchor steel rod insertion hole 29, dropping the lower end of the PC column 22 into the recess 24, joining both pedestal plates 25 and 30, and inserting the anchor steel rod 26 into the anchor steel rod insertion hole 29. Fixing plate and nut 31 at the upper end of 26
Fit and tighten. As a result, the PC column 22 stands vertically on the foundation 21. In addition, both pedestal plates 2
5. Adhesive (zero joint) is interposed between 30 and 30.

After making the PC column 22 independent in this way, the concave portion 24
Cast-in-place concrete 32 is placed in the gap inside, and the overhanging part 28 at the lower end of the PC column is embedded in the foundation 21.

(Effects of the Invention) As mentioned above, in the method of the present invention, since the PC column is fixed to the concrete foundation by the anchor steel rod, sufficient bonding can be obtained even if the recessed part of the foundation is deepened. Therefore, the horizontality of the bottom surface of the concave part can be easily and accurately made, and since the anchor steel rod is fixed by passing it through the overhanging part on the outer circumference of the lower end of the PC column, the fixing work is easy. It will be safe and easy.

Furthermore, in the present invention, the pedestal plate is fixed to the PC column side and the foundation side at the required angle in advance, so the required verticality of the PC column can be adjusted simply by erecting the PC column and joining both pedestal plates to each other. As a result, PCs in the field
This eliminates the need to adjust the verticality of columns and also eliminates the need for support wires, which has the effect of allowing a wider range of work sites to be used.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of an example of the joint between a PC column and foundation erected according to the present invention, Figure 2 is a plan view of the joint before pouring concrete on site, Figure 3 and Figure 4 are They are sectional views of separate conventional examples. 21... Concrete foundation, 22...
PC column, 23...Foundation pile, 24...Concave portion, 25...Foundation side pedestal plate, 6...
... Anchor steel rod, 27 ... Fixture fitting, 8.
...Protrusion, 29...Anchor steel rod insertion hole, 0...Column side pedestal plate, 31...
・Natsuto, 2...Cast-place concrete.

Claims (1)

[Claims] An overhang is integrally formed on the outer peripheral surface of the lower end, an anchor steel rod insertion hole is opened vertically in the overhang, and a column side pedestal plate perpendicular to the column axis is fixed to the bottom surface. Using precast concrete columns (hereinafter referred to as PC columns),
When constructing the concrete foundation on which the PC column is supported,
A recess into which the lower end of the PC column is inserted is formed on the upper surface of the foundation, and the upper end side of an anchor steel rod for fixing the PC column is protruded from the bottom of the recess, and the upper end of the anchor steel rod is provided on the bottom of the recess. The foundation side pedestal plate, which is flat, is fixed in a horizontal position, the PC column is erected and inserted into the recessed part, and the anchor steel rod is inserted into the anchor steel rod insertion hole to join the two pedestal plates to each other. The PC column is made to stand on its own by fixing an anchor steel rod under tension on the overhanging part, and then pouring cast-in-place concrete into the recessed part and embedding the lower end of the PC column in the concrete foundation. How to erect a PC pillar on top.