JPH09195673A - Vertical shaft casing under propulsive engineering method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To scrape off a soil layer remaining along an inner peripheral surface of a vertical shaft casing to be oscillated and press fit and to naturally exhaust it. SOLUTION: A plural number of triangular projections 12 are provided along an inner peripheral surface in the neighborhood of a lower end of a casing 11. Whenever the casing 11 is repeatedly rotated in arrow (a) and (b) directions, the projections 12 work on a soil layer S too much to be removed by a bucket of a power shovel but left behind and scrape out and off this soil layer S inward. It is possible to exhaust this soil by the bucket of the power shovel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft casing used in a propulsion method in which a propulsion pipe such as a fume pipe is buried in the ground.

[0002]

2. Description of the Related Art Conventionally, when a cylindrical starting or reaching vertical shaft is installed in a propulsion method, as described in, for example, Japanese Patent Application No. 6-191101 filed by the applicant of the present invention, a tip end is cut. The outer circumference of a cylindrical shaft casing having a blade is gripped by an annular gripping member of a rocking press-fitting device, and the rocking press-fitting device pushes the casing down repeatedly while repeatedly pressing the casing, and at the same time, inside the casing as appropriate. Excavate the earth and sand with a power shovel. Then, while repeating this, if necessary, a casing (middle casing) is added to further press-fit into the ground and remove the soil inside, thereby forming a vertical shaft with a predetermined depth.

By the way, since the bucket of the power shovel is usually rectangular, it is essentially impossible to excavate a circular hole in plan view which is exactly along the circular inner surface of the casing, and the inner surface of the bucket and the casing during excavation. Since it is desirable to avoid contact with
As shown in, the soil layer S having a predetermined thickness remains on the inner surface of the casing 1 even after excavation. If this is soil close to the surface, the viscosity will not be so high that it will naturally collapse during the work process, and people can scrape it off from the surface using a spatula, but a layer of clay with a high viscosity (clay When the (layer) remains on the inner surface of the casing 1, it is difficult to scrape off the ground surface with a spatula, and there is a problem that the press-fitting and excavating work of the casing is interrupted due to the scraping work, and the work efficiency decreases.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and does not require manual labor and does not interrupt the press-fitting and excavating work of the casing.
The purpose is to scrape off a layer of soil that could not be removed by a bucket of a power shovel.

[0005]

DISCLOSURE OF THE INVENTION The present invention is to improve the structure of the casing itself to achieve the above-mentioned object. A protrusion for scraping off the soil remaining along the inner peripheral surface of the casing is provided on the inner peripheral surface of the casing. The shaft casing in the propulsion method is characterized in that a plurality of shaft casings are provided along the surface. In this shaft casing, preferably, the protrusion is provided near the lower end of the casing so that the soil attached to the bottom of the casing can be removed.

[0006]

DETAILED DESCRIPTION OF THE INVENTION A more specific description will be given below with reference to FIGS. In FIG. 1, triangular projections 12 are arranged on the inner surface at equal intervals in the vicinity of the cutting blade 11a of the casing 11 (position immediately above). This protrusion 12
Is formed by vertically welding the both end edges of angle-shaped steel (angle) cut into a short length to the inner surface of the casing.

When this casing 11 is used as a vertical shaft casing, the casing 11 is repeatedly rotated in the directions of arrows a and b in FIG. 1 (b).
The soil layer S that could not be completely removed along the inside of the
Does not rotate), the projection 12 acts like a spatula, and scrapes or scrapes the soil layer S inward as shown by a virtual line, for example. The soil thus scraped or scraped off can be easily removed by the bucket of the power shovel, so in the end, rocking press-fitting and excavation work as usual can be performed without any special operation. The presence of the soil layer naturally eliminates the soil layer on the inner surface of the casing. In addition, this protrusion 1
In a normal casing not provided with 2, the casing and the soil layer S only slide on each other even if the casing is repeatedly rotated, and such an action cannot occur.

2 to 4 show another example of the projections. In FIG. 2, strip-shaped projections 22 are vertically welded along the inner peripheral surface of the casing 11, and in FIG. Is a strip-shaped projection 32 which is welded while alternately inclining in opposite directions, as shown in FIG.
1 shows a plate-like protrusion 42 horizontally welded on both vertical edges, both of which act like a spatula on the soil layer S like the protrusion 12 of FIG. Scratch out or scrape off. The installation intervals of the protrusions 12 to 42 are
The rocking distance of the casing 11 is preferably twice or less so that the protrusion can exert a spatula effect on the entire circumference of the soil layer S as the casing 11 is repeatedly rotated. Further, the height of the protrusion is lower than that of the soil layer S in FIG. 1, but may be the same or higher.

[0009]

According to the shaft casing of the present invention, the projection provided on the inner peripheral surface of the casing acts like a spatula on the soil layer remaining along the inner peripheral surface of the casing. Since the soil is scraped out or scraped off, the soil layer on the inner peripheral surface of the casing can be naturally removed only by performing the conventional rocking press-fitting and excavating work. Therefore, no manpower for scraping is required and work efficiency does not decrease.

[Brief description of the drawings]

FIG. 1 is a side view (a) and a sectional view (b) of a casing according to the present invention.

FIG. 2 is a side view (a) and a sectional view (b) of another example of the casing according to the present invention.

FIG. 3 is a side view (a) and a sectional view (b) of still another example.
It is.

FIG. 4 is a side view (a) and a sectional view (b) of still another example.
It is.

FIG. 5 is a side view (a) and a sectional view (b) showing a layer of soil remaining along the inner peripheral surface in a conventional casing.

[Explanation of symbols]

 11 Casing 12, 22, 32, 42 Projection S Soil layer

Claims (2)

[Claims] 1. A vertical casing in a propulsion method, wherein a plurality of protrusions are provided along an inner peripheral surface of the casing. 2. The shaft casing in the propulsion method according to claim 1, wherein the protrusion is provided near the lower end of the casing.