JPH0338369B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method of installing sheet piles.

When the roots are cut during building construction, a continuous underground wall is formed using sheet piles to prevent the surrounding ground from collapsing and the surrounding buildings from subsidence.

In order to install this sheet pile underground, conventionally, as shown in Figure 1A, an auger screw 1
Form a vertical hole A′ while excavating the soil according to 1.
At the same time, the sheet pile 12 is buried in the ground along the vertical hole A', and the sheet pile 1
An installation method is used in which the auger screw 11 is pulled out while rotating the auger screw 11 in the opposite direction after the lower end of the auger screw 2 reaches a predetermined depth.

However, the ground inside the vertical hole A' is extremely soft due to the fact that a lot of earth and sand is removed when forming the vertical hole A', and the volume is reduced due to the pulling out of the auger screw 11. For this reason, as shown in Figure 1B, when a root cut is made in the ground on the building construction side, the sheet pile 12 corresponding to the vertical hole A' on the root cut side begins to fall down to the root cut side, and the surrounding ground is caused by this. The formation of a gap with C causes the collapse of the surrounding ground C, and also the sheet pile C
Collapses of the surrounding ground C were also observed at locations corresponding to the vertical hole A' on the opposite side of the root cutting side, and these often led to loosening of the surrounding ground C and caused the subsidence of neighboring buildings. .

The purpose of the present invention is to strengthen the ground strength within a vertical hole through simple improvements and to prevent the subsidence of neighboring buildings.

Hereinafter, embodiments of the method of the present invention will be explained based on the drawings from FIG. 2 onwards. First, as shown in FIG. 2,
A driving elevating body 2 equipped on a construction machine 1 is provided with a continuous spiral auger screw 3 and a cylindrical body whose inner surface is coated with friction reducing material such as Teflon, and the inner surface of the auger screw 3 is concentrically arranged inside the auger screw 3. The blind casing 4 and the sheet pile 5 to be buried are set in a hanging manner, and as shown in FIG. 3, the auger screw 3 is rotated forward in the excavation direction and While rotating the blind casing 4 in the opposite direction, the elevating body 2 is forcibly pushed down, and while the soil excavated by the auger screw 3 is stored in the blind casing 4, a vertical hole A is excavated in the ground. do.

At the same time, the sheet pile 5 is moved to the vertical hole A.
It is buried underground along the side.

As shown in FIG. 4, when the lower end of the sheet pile 5 reaches a predetermined depth, the sheet pile 5
is disconnected from the elevating body 2, and then the auger screw 3 and the blind casing 4 are respectively rotated in the opposite direction while the elevating body 4 is forcibly raised;
While backfilling the vertical hole A with the excavated soil stored in the blind casing 4, the auger screw 3
At the same time, the blind casing 4 is pulled out from the vertical hole A.

With the above, the installation of one sheet pile 5 is completed, and from now on, the installation of one sheet pile 5, 5
By sequentially installing the sheet piles 5 while connecting them, a continuous underground wall B as shown in FIG. 1B is formed.

In addition, if the excavated soil is clayey, for example,
It is assumed that the excavated soil will be difficult to separate from the spiral blades of the auger screw 3, making it difficult to backfill into the vertical hole A. In this case, it is recommended to supply fluids such as water or bentonite. One way to do this is to make the auger screw shaft into a cylindrical structure, form an appropriate hole in the cylindrical wall, connect a fluid supply pipe to the upper end of the cylindrical shaft, and adjust the flow as necessary. All you have to do is discharge the fluid.

As explained above, the method for installing a sheet pile according to the present invention uses a continuous spiral auger crew and a blind casing whose inner surface is friction-reduced and which houses the auger crew. A vertical hole is excavated in the ground while the sheet pile is stocked in the ground, and at the same time, a sheet pile is buried in the ground along the vicinity of the vertical hole, and after the lower end of the sheet pile reaches a predetermined depth, the auger The system is characterized in that the auger screw and the blind casing are pulled out while rotating the screw in the opposite direction, and the excavated soil stored in the blind casing is backfilled into the vertical hole.

That is, in the past, the excavated soil was discharged, but in the present invention, the excavated soil is stored in a blind casing with a low friction inner surface to prevent excessive resistance, and the excavated soil is removed from the auger screw. In addition, when the blind casing is pulled out, this accumulated excavated soil is forcibly backfilled into the original vertical hole, thereby restoring the ground strength within the vertical hole to a state close to its original state. As a result, it becomes possible to extremely effectively prevent the inclination of the sheet pile and the associated collapse of the surrounding ground, or the collapse of the surrounding ground into the vertical hole itself, which in turn eliminates the problem of subsidence in neighboring buildings. I was able to do it.

[Brief explanation of the drawing]

FIG. 1A is an explanatory diagram of a conventional sheet pile installation method, and FIG. 1B is a partial perspective view of a continuous underground wall according to the conventional method. FIG. 2 and subsequent figures relate to embodiments of the present invention, and FIGS. 2 to 4 are explanatory diagrams showing the procedure for installing sheet piles. 3...Auguscrew, 4...Blind casing, 5...Sheet pile, A...Vertical hole.

Claims (1)

[Claims] 1. Excavating a vertical hole in the ground while storing excavated soil in the blind casing using a continuous spiral auger crew and a blind casing that houses the auger crew and has an inner surface treated to reduce friction; At the same time, a sheet pile is buried in the ground along the vicinity of the vertical hole, and after the lower end of the sheet pile reaches a predetermined depth, the auger screw and the blind casing are removed while rotating the auger screw in the opposite direction. A method for installing a sheet pile, comprising pulling out the sheet pile, and backfilling the vertical hole with the excavated soil stored in the blind casing.