JPH026100Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a steel material for constructing an underground continuous wall, which is used in a method of constructing an underground continuous wall by penetrating into the soil in a connected state and injecting grout when pulling it out.

A relatively simple construction method for water-stopping walls and earth-retaining walls is to penetrate H-shaped steel or similar shaped steel into the soil, and when pulling it out, inject mortar or other grout to create an underground continuous wall. There is a known construction method for creating.

Steel materials used in this type of construction method usually have a fitting part formed at the end for connection, and adjacent steel materials are penetrated into the soil while fitting into each other, and are pulled out one after another from the end. However, there were the following problems, especially when pulling it out.

That is, the steel material that has penetrated into the soil has a large friction between its side surface and the earth and sand, and therefore, the earth and sand adhere to the steel material and go up together with the steel material.

Therefore, the void for grout injection formed in the soil by pulling out the steel material is considerably larger than the cross-sectional area of the steel material, and therefore the amount of grout injected greatly exceeds the design value.

This phenomenon was particularly noticeable in highly viscous ground, making the construction method less economical.

This idea was created in view of the technical issues mentioned above, and its purpose is to improve the economic efficiency of the construction method by reliably removing the earth and sand that adheres to steel materials that have penetrated into the ground. The company provides steel materials for constructing underground continuous walls.

To achieve this purpose, this device has a flat base and a pair of fitting parts provided at both ends of the base, which are laterally connected and penetrated into the soil, and are pulled out while being inserted into the soil. A steel material used when constructing an underground continuous wall by injecting grout, in which grout is injected into the part where the base and the fitting part are joined, narrowing the base and extending vertically over the entire length of the base. A pipe for the steel material and an ejection pipe are respectively installed, the pipe has an opening at the lower end, the ejection pipe has a plurality of holes opened toward the fitting part along the longitudinal direction, and When pulling out the steel material, pressurized water is injected into the ejection pipe, and the pressurized water is discharged from the drilled hole to remove earth and sand attached to the steel material.

Hereinafter, preferred embodiments of this invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of the steel material for constructing an underground continuous wall according to this invention.

The steel material 10 shown in the figure has a roughly H-shaped cross section with a pair of flanges 10b, 10b fixed to opposite ends of a flat base 10a. L-shaped bent portions 12 are formed respectively, and a substantially concave female fitting portion 14 is provided.
The other flange 10b is a flat male fitting portion 15.

These male/female fitting parts 15 and 14 are mutually fitted with fitting parts of other adjacent steel materials when the steel material 10 is penetrated into the soil, and are for connecting the steel materials 10 in the lateral direction. It is.

Then, the base portion 10a and the flanges 10b, 1
Four hollow pipes are fixed to the corners where the pipes 0b and 0b are joined, extending in the vertical direction along the side surfaces of the pipes, and a pair located diagonally are the grout injection pipes 16, 16, and the other pair are ejection pipes 18,18.

The tips of the ejection pipes 18, 18 are located at positions slightly retreated from the lower end of the base 10a, while the tips of the grout injection pipes 16, 16 are approximately at the same level as the lower end of the base 10a.

Further, the jet pipes 18, 18 have a number of perforated holes 20, 2 through which pressurized water is discharged so as to recede at a predetermined angle θ with respect to the outer surface of the base 10a to which the jet pipes are fixed.
0... are formed to face the fitting portion 15 or 14 side, and the vertical intervals between the perforated holes 20 are evenly spaced.

The steel material 10 configured in this manner penetrates into the soil by horizontally connecting the male and female fitting parts 15 and 14 while sequentially fitting them together, and then is used for grout injection by pulling out the steel material 10 one by one from the end steel material 10. pipe 16,
Grout is injected via 16.

At this time, pressurized water is injected into the ejection pipes 18, 18 from the upper end side by a water supply pump or the like.

The injected pressurized water is discharged from the perforated holes 20, 20, . . . of the jet pipes 18, 18 toward the other flange 10b.

Therefore, the earth and sand adhering to both sides of the base 10a of the steel material 10 are removed due to the discharge pressure of pressurized water discharged from the drilled hole 20 and the decrease in adhesive force due to water.
It separates from the outer surface of the base 10a.

Therefore, the steel material 10 is easily pulled out, dirt is prevented from accumulating, the gap into which the grout is injected almost matches the cross-sectional shape of the steel material 10, and the amount of grout injected is almost as designed. Eliminates the need to use excessive grout.

Note that the position of the perforation hole 20 of the ejection pipe 18 is not limited to the above embodiment, and may also be provided on the side of the flange 10b to which the ejection pipe 18 is fixed.

In addition, in the case of extremely sticky geology, if the amount of water released from the jet pipe 18 increases and there is a possibility that the water content of the injection grout becomes excessive, the water content of the injection grout should be adjusted. is desirable.

Furthermore, the shape of the perforation hole 20 of the ejection pipe 18 may be not only circular but also an elongated oval shape.

As explained in the examples above, the steel material for constructing underground continuous walls according to this invention has excellent effects such as improving construction efficiency by reliably removing soil and sand attached to the steel material. It will be done.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is a plan view of the main part of FIG. 1, and FIG. 3 is a sectional view of the main part of FIG. 10...Steel material, 18...Ejection pipe, 20...Drilling hole.

Claims (1)

[Scope of utility model registration request] It has a flat plate-shaped base and a pair of connecting fittings provided at both ends of the base, and is inserted horizontally into the soil and injected with grout while being pulled out to form a continuous underground wall. A grout injection pipe and a spouting pipe, which are made of steel used in construction, are installed at the joint between the base and the fitting part, and extend vertically across the base across the entire length of the base. ,
The pipe has an opening at the lower end, and the injection pipe has a plurality of holes opened toward the fitting part along the longitudinal direction, and pressurized water is injected into the injection pipe when pulling out the steel material. A steel material for constructing an underground continuous wall, characterized in that the pressurized water is discharged from the bored hole to remove earth and sand adhering to the steel material.