JPH0649976B2 - How to build a true pillar - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for erection of a true column at a predetermined pile driving place in civil engineering work, building construction work and the like.

[Prior Art] Conventionally, the following method has been used to build a true pillar in civil engineering work or construction work.

That is, as shown in FIG. 7 and FIG. 8, the ground around the casing 1 press-fitted into the ground by a press-fitting device using hydraulic pressure while excavating with a hammer grab is replaced by concrete 2, a lining plate 3, etc. The gantry 4 is reinforced so that it can sufficiently bear the weight of the true column 7, and the pedestal 4 for supporting the true column 7 is set on it. The center of the gantry 4 is aligned with the center of the casing 1, and While checking the degree at level 5, adjust with jack 6.

Next, as shown in FIG. 9, a hanging jig 8 is connected to the upper end of the structure post 7, and angles 9 are radially welded near the lower end, and horizontal hydraulic jacks 10 are respectively attached to these angles 9. Is detachably attached from the outside by a wire, and each horizontal hydraulic jack 10 is connected to a hydraulic hose 11 extending to the upper part of the structure column 7.

Then, the true column 7 is inserted into the casing 1, and the bracket 12 provided on the hanging jig 8 is placed on the hydraulic jack 13 on the pedestal 4 so that the pedestal 4 is supported and the turntable 14 is turned on. The position of the upper end portion is adjusted by the hydraulic jack 13 while the positioning is performed by the direction fixing device 15, and the vertical accuracy is adjusted by remotely operating the horizontal hydraulic jack 10 while watching the inclinometer 16 on the ground.

Then, when the vertical accuracy of the true column 7 comes out, a required amount of concrete is placed in the casing 1, the casing 1 is pulled out, the horizontal hydraulic jack 10 is taken out with a wire, and then backfilling is performed. Is.

However, in the above-mentioned conventional method, since the large weight of the true structural column 7 is supported by the gantry 4 installed on the ground, it is not only necessary to reinforce the ground enough to withstand the weight of the true structural column 7. Instead, a strong base 4 equipped with various adjustment mechanisms was required, and a horizontal hydraulic jack 10 was also required for achieving verticality. Therefore, the equipment is very complicated, and it takes time to install and remove it.
Also, it is troublesome to adjust the verticality of the structure post 7 by the horizontal hydraulic jack 10, and a lot of time and effort are spent to build the structure post 7. Moreover, the accuracy of about 1/800 is usually required for the construction of such a true pillar, but with the conventional method, it becomes difficult to move when the weight of the true pillar becomes large. There is also a drawback that it becomes difficult to adjust and the required accuracy is difficult to obtain.

[Problems to be Solved by the Invention] An object of the present invention is to provide a method for erection of a true column that is simple in equipment and easy in construction.

[Means for Solving the Problems] In order to solve the above problems, according to the present invention, a structure column having a reinforcing bar cage fixed to the lower end is hung by a wire and inserted into the casing press-fitted into the ground. , The structural column is positioned vertically with respect to the casing while vertically suspended by the wire with the rebar cage slightly separated from the bottom of the hole, and then vertically fixed by the fixing frame placed on the upper end of the casing. Then, there is provided a method of erection of a true column, which comprises pouring concrete into the hole and then withdrawing and backfilling the casing.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the method of the present invention will be described in more detail with reference to the drawings.

In FIG. 1, reference numeral 20 denotes a casing press-fitted into the ground. The casing 20 is pressurized by a conventionally known method, for example, a hydraulic press-fitting device 21 while excavating the ground with a hammer grab. It is pressed in by. As shown in FIG. 2, at the upper end portion of the casing 20, a mark 23 to be aligned with the center of the true-fixation column 22 so that the true-fixation column 22 (see FIG. 3) can be set at the center thereof.
Are attached in the X and Y directions.

Next, as shown in FIG. 3, the structure pillar 22 having the reinforcing bar cage 24 fixed to the lower end portion by the steel material 25 is used to attach the wire 26 by the crane.
And hang it vertically, and gently insert it into the center of the inside of the casing 20. Then, the structure column 22 is attached to the rebar cage 24 at the lower end.
Is hung vertically from the bottom of the hole,
By aligning the center of the true post 22 with the mark 23 attached to the casing 20 while checking with the transit 27, the true post 22 is positioned at the center of the casing 20, and the true post 22 is located at the upper end of the casing 20. It is fixed vertically by the fixed frame 28 placed. At this time, since the structure column 22 is suspended by the wire 26, the vertical state can be easily maintained regardless of the weight of the structure column. Therefore, the vertical degree can be adjusted by the horizontal hydraulic jack as in the conventional case. Without doing
The verticality can be easily and reliably obtained. In addition, the crown of the true pillar 22 is confirmed at the level. Further, when the true pillar 22 is hung by the wire 26 as described above, the true pillar may be directly hung by the wire, but it may be hung by an appropriate hanging jig.

As shown in FIG. 4, the fixed frame 28 has the structure column 22 with the Y-shaped column.
Two frame members 29, 29 that are held in the Y direction are provided with brackets 30, 30 that hold the true column 22 in the X-X direction, and are detachably fixed to the upper end of the casing 20 by appropriate means. You can do it.

After fixing the structure columns 22 in this way, as shown in FIG. 5, the tremie pipes 32 are inserted into the casing 20 while sequentially joining them so as not to hit the rebar cages 24.
The slime that has settled during the installation of 24 and the tremie pipe 32 is removed and concrete is poured.

To remove slime, insert an air hose inside the tremie pipe 32 and attach an air lift device to the tip of the tremie pipe 32, and press about 7 atm of air into the tremie pipe 32 to pump mud water near the bottom of the hole. By doing. In this case, to prevent the pumping water from concentrating on one hole bottom,
It is necessary to constantly change the position of the pipe and evenly pump water from the entire bottom of the hole. Further, it is desirable to constantly monitor so that the level of the stabilizing solution in the hole does not drop due to pumping, so that water can be supplied as needed.

When the slime has been removed, the required amount of concrete 34 is poured into the casing 20 through the tremie pipe 32 (see FIG. 6). Since this concrete is placed underwater, it means that mixing of concrete and muddy water is prevented.
It is preferable to use a plunger system in which the plunger 33 is inserted into the tremie pipe 32 and driven. Moreover, by separating the lower end of the tremie pipe 32 from the bottom of the hole by about 20 to 25 cm, it is possible to prevent the separation of the concrete.

When the pouring of concrete is completed, the tremie pipe 32 is pulled out, the fixed frame 28 is once removed, the casing 20 is pulled out by the press fitting device 21, and the press fitting device 21 is removed as shown in FIG. The lining plate 35 is installed, and the fixed frame 28 is set on the lining plate 35 to re-establish the true pillar.
Support 22. Then, while looking into the transit from the X-Y2 direction, pull the construction column 22 with the weight 36 to adjust the column core, suck up the stabilizing liquid in the hole with a pump, and then backfill it with high quality residual soil 37. Building of pillar 22 is completed.

The true-columns 22 are not limited to those having the H-shaped cross section as described above, and may be o-shaped, □ -shaped, or any other cross-sectional shape.

[Effects of the Invention] According to the present invention as described above, the verticality of the column is increased by suspending it with a wire, and it is positioned with respect to the casing in the suspended state, and then the upper end portion of the casing. Since it is fixed vertically by the fixing frame placed on the, the verticality can be extremely easily obtained regardless of the weight of the structure column, and its position can be adjusted. As described above, it is not necessary to use complicated devices such as horizontal hydraulic jacks to adjust the verticality and position, and to support various heavy articulated columns. It is not necessary to provide a pedestal having a complicated structure with an adjusting mechanism and high strength on the ground, and it is not necessary to reinforce the ground for mounting the pedestal.

In addition, generally, when concrete is poured into the casing into which the true pillar is inserted, a very large pressing force of the concrete acts on the true pillar. In this case, concrete is poured at a point on the side of the true column, so the force acting on the true column becomes a biased force from the side, and this action force causes the true column to move or tilt. Then, there was a problem that the build-up accuracy was lowered. In particular,
In the method that does not use a horizontal hydraulic jack, the concrete column is easy to move due to the acting force of concrete. On the other hand, in the present application, the reinforcing bar cage is integrally fixed to the lower end of the structure pillar, and the concrete is poured while the lower end portion of the structure pillar is supported by the reinforcing bar cage. Even if the pressing force by the force acts on the true column, the true column is firmly supported at the center by the rebar cage and does not move,
Moreover, the injected concrete is dispersed and diffused by a large number of fine wires forming the rebar cage, and not only exerts an action force by concentrating on only one point, but also acts on each fine wire in a dispersed manner. As for the acting force, they will cancel each other out.
It does not act strongly from the direction, and by these synergistic effects, it is possible to surely prevent the movement and inclination of the concrete columns during concrete pouring.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state before the construction of the true column,
The figure is a plan view, FIG. 3 is a cross-sectional view of a case where a true column is inserted in a casing, FIG. 4 is its plan view, FIG. 5 is a cross-sectional view showing a state before placing concrete, and FIG. Is a cross-sectional view showing a state immediately before completion of building, and FIGS. 7 to 9 are explanatory views showing a conventional method of building a true-column. 20 …… Casing, 22 …… Structured pillar 24 …… Reinforcing cage, 26 …… Wire 28 …… Fixed frame, 34 …… Concrete

Claims (1)

[Claims] 1. A structure column having a reinforcing bar cage fixed to the lower end is inserted by being suspended by a wire into a casing press-fitted into the ground, and the structure column is in a state in which the reinforcing bar cage is slightly separated from the hole bottom. While vertically suspended with the above wire, after positioning with respect to the casing, fix vertically with a fixing frame placed on the upper end of the casing, and then place concrete into the hole and pull out and refill the casing. The method of erection of the true pillar which is characterized by performing.