JPH0219247B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a method for drawing steel materials used as the core material of steel piles for earth retention, which are constructed to bear the surrounding soil and water pressure during foundation work of buildings. be.

Conventionally, when constructing foundations for buildings or constructing underground buildings, an earth retaining wall has been formed around the building and the inside of the wall has been excavated. Steel piles for earth retention were formed at appropriate locations.

However, in recent construction work, strict regulations have been put in place to deal with pollution problems such as noise and vibration, and especially in cities and their surrounding areas, construction methods in which H-shaped steel etc. are directly driven or pulled out as earth retaining steel piles are rarely used. I'm in a state where I can't.

For this reason, various construction methods have been proposed to solve the pollution problem. For example, a vertical hole is dug with an auger etc. at the location where the earth retaining steel pile is to be driven, and mortar is injected into the vertical hole. However, one such method is the so-called mortar injection method in which H-shaped steel is inserted before the mortar hardens.

According to this mortar injection method, the steel pile for earth retaining can be constructed without generating any noise or vibration, but when it is pulled out, the H-beam steel and mortar are stuck together. noise·
It is extremely difficult to carry out construction without generating vibrations, making it almost impossible.

Therefore, the used H-shaped steel was buried and left unused, which was an extremely uneconomic construction method.

Furthermore, in order to collect used steel materials such as H-shaped steel, a construction method has been proposed in which the core material of the earth retaining steel pile is covered with a vinyl sheet or a vinyl sheet with bubbles. However, although this construction method can be used without generating noise or vibration during the drawing of steel materials, vinyl sheets and bubbled vinyl sheets are relatively expensive and require equipment to cover them. There were economic problems.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to reduce the noise pollution that pollutes the surrounding environment by making the steel material that is the core material of earth retaining steel piles relatively simple. The object of the present invention is to provide an economically advantageous construction method that can be pulled out and reused without generating vibration.

In order to achieve this purpose, the drawing method for earth retaining steel materials according to the present invention involves coating the steel material with a cardboard layered with a corrugated core material and a flat kraft paper, and the outer surface of which has been treated to be water repellent. , the ends are butted and fixed together, concrete is poured into the vertical hole, and before the concrete hardens, the steel covered with the cardboard is buried, so that the cardboard is placed between the concrete and the steel. It has a feature that the steel material can be separated from the concrete and pulled out by interposing the steel material.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 to FIG. 6 show an embodiment of the drawing method for earth retaining steel materials according to the present invention.

The drawing method for earth retaining steel shown in the figure first involves placing an auger 10 at a predetermined location around the building to be constructed.
A vertical hole 12 is formed using an excavator such as the like, and concrete 14 is poured into this vertical hole 12 (first and second
(see figure).

After this, as shown in FIG.
This method is used to form steel piles for earth retention by burying
The drawing method of the present invention is characterized in that, prior to burying, the steel material 16 made of H-shaped steel is coated as described below.

That is, as shown in the enlarged cross-sectional view in FIG.
A first core material 18 formed into a waveform with a relatively small amplitude and a second core material 20 formed into a waveform with a larger amplitude than the first core material 18 are made of three sheets of flat craft paper 22a, 22b, FIG. 4 shows a sheet-like cardboard 24 which is sandwiched in a sandwich-like manner by 22c to form a layer, and which is made water-repellent or water-resistant by applying paraffin or the like to the outer surface of the kraft paper 22a forming the outer surface. As shown in the above, the cardboard 2
The kraft paper 22c of No. 4 is on the inside, and creases 26 are provided so as to match each side of the steel material 16, and the ends are folded and covered along the surface of the steel material 16 at the construction site. They are abutted on the left and right flanges 16a, fixed with adhesive tape 28, and covered as shown in FIG.

In this case, the tip of the steel material 16 covered with the cardboard 24 is formed by forming the cardboard 24 slightly longer than the steel material 16 and bending it inward at the tip.
Although it is possible to fix with adhesive tape 28,
Preferably, a shoe 30 made of synthetic resin or the like is attached.

Steel material 1 covered with cardboard 24 as described above
6 is a vertical hole 12 in which the concrete 14 is poured.
The steel pile is lifted up by a crane or the like and buried in the concrete 16 before it hardens, and when the concrete 16 hardens, it becomes a steel pile for earth retention.

At this time, since the outer surface of the cardboard 24 has been treated with water repellent treatment as described above, there is no risk of absorbing moisture from the concrete 16 and collapsing the above-mentioned layered structure, and the surrounding area that is added to the earth retaining steel pile is not affected. The soil of
The above-mentioned two-stage corrugated core material 18, 2 is also suitable for water pressure.
0 relieves these external pressures by elastically deforming.
Acts as an absorber.

What is even more noteworthy is that as mentioned above, the presence of the cardboard 24 between the concrete 14 and the steel 16 prevents the concrete 14 and the steel 16 from sticking together, making it unnecessary to use steel piles for retaining the earth after building the building. In such a case, the extremely simple steel material 16 can be pulled out and reused using a crane or the like without generating noise or vibration.

In this case, when pulling out the steel material 16, the cardboard 24
Even if a part of the sheet is pulled out while still stuck, it can be incinerated and there is no problem when disposing of it like conventional vinyl sheets.

Further, even if part or all of the cardboard 24 remains fixed to the concrete 16, there is no problem in this respect as it will corrode in the soil. moreover,
The cardboard 24, which exhibits the above-mentioned remarkable effects, is relatively inexpensive, can be stacked in flat plate form and transported to the construction site, and can be covered with adhesive tape 28 at the construction site. It is also an extremely economically advantageous construction method as it is a simple process.

FIG. 7 shows another embodiment of the drawing method for earth retaining steel materials according to the present invention. To explain only the characteristic points, the abutting portions of the ends of the cardboard 24 are connected to the steel materials 16. web 16b
With this configuration, when the cardboard 24 is butted, the cardboard 24 will be pressed against the flange 16a side of the steel material 16, and the degree of adhesion between the steel material 16 and the cardboard 24 will be further improved. Become desirable.

In the above embodiments, the steel material 16 was described as an H-shaped steel, but the present invention is not limited to this, and the folds 26 of the cardboard 24 may be provided to match the shape, and a wide range of steel materials 16 may be used. Can be easily adapted to shapes.

Further, the length of the cardboard 24 can be formed by dividing it in the axial direction as appropriate depending on the length of the steel material 16, and the cardboard 24 can be bonded with adhesive tape 28.

As described above, the present invention utilizes a drawing method for steel materials for earth retaining, in which the steel material is covered with folded cardboard, which is formed in layers with a corrugated core material and flat kraft paper, and whose outer surface is treated with water repellent treatment. After fixing the ends with adhesive tape, concrete is poured into the excavated vertical hole, and before the concrete hardens, the steel covered with the cardboard is buried in the concrete. This is made by interposing cardboard between the concrete and steel so that the steel can be separated from the concrete and pulled out, making it possible to recover and reuse expensive steel without causing pollution problems such as noise and vibration. In addition, the cardboard and adhesive tape necessary for implementation are inexpensive;
These materials are extremely economical as they are easy to handle and work.

[Brief explanation of drawings]

FIGS. 1 to 6 show an embodiment of the drawing method for earth retention steel materials according to the present invention, and FIG.
3 to 3 are cross-sectional views showing the construction order of the construction method, and the construction is carried out in the order shown in FIGS. 1 to 3. FIG. 4 is a plan view of the cardboard covering the steel material, FIG. 5 is a perspective view of the steel material covered with the cardboard, and FIG. 6 is an enlarged sectional view of FIG. 5. FIG. 7 is an enlarged cross-sectional view showing another embodiment of the cardboard fixing method. 10... Auger, 12... Vertical hole, 14... Concrete, 16... Steel material, 18... First core material, 20... Second core material, 22a, 22b, 22
c...Craft paper, 24...Cardboard, 26...
Fold line, 28...adhesive tape, 30...shew.

Claims (1)

[Claims] 1. After excavating and forming a vertical hole around the building to be constructed in advance and pouring concrete into the vertical hole, before the concrete hardens, steel materials are buried to form steel piles for earth retention, and the construction of the building is completed. In a construction method in which the steel material is pulled out after construction, a sheet-like cardboard layered with a corrugated core material and flat kraft paper and treated with water-repellent treatment on the outer surface is stretched along the surface of the steel material at the construction site. The steel material covered with the cardboard is then buried in the concrete, thereby interposing the cardboard between the concrete and the steel material. A method for drawing out steel materials for earth retention, characterized in that the steel material is separated from the concrete and pulled out.