JP2775609B2 - Water collection method and water collection structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for collecting groundwater by horizontal hole boring drainage in a landslide prevention method.

[0002]

2. Description of the Related Art In a landslide prevention method, in draining a horizontal hole in a shirasu or sandy soil layer, a moving earth mass loosened due to fluctuations is excavated.
As in the conventional method, the water collection pipe is simply inserted into the casing pipe and buried, and then buried to the planned depth, and then the casing pipe is removed. There is an inherent problem that only the casing pipe can be easily removed after filling.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above,
It is an object of the present invention to provide a water collecting method and a water collecting structure in which a casing pipe can be easily removed after a water collecting pipe is inserted.

[0004]

The water collecting method according to the first invention comprises:
Boring to the planned depth while inserting the casing pipe, and after inserting the casing pipe to the planned depth,
Withdrawing the inner rod, then a number of drain holes are provided around, and a short fixing pipe with an open end is inserted into the casing pipe, and the tip of the fixing pipe projects from the casing pipe. It is driven into the ground for the required length, and then a number of drain holes are provided around the inside of the casing pipe, and a water collecting pipe formed by projecting an anchor body at the closed end is inserted. The anchor body at the tip is driven into the earth and sand filled inside the anchoring pipe, and the soil between the interior of the anchoring pipe and the outer periphery of the anchoring pipe protruding from the casing pipe are tightened by negative dilatancy. After tightening the casing, the casing pipe is removed.

A water collecting structure according to a second aspect of the present invention has a short fixing pipe having a plurality of drain holes formed therearound and having a leading end opened and provided horizontally ahead of a predetermined depth of the ground. A water collecting pipe in which a number of drain holes are provided around the outer periphery of a long pipe main body, and an anchor body projecting from the closed end is driven into earth and sand filled inside the fixing pipe. .

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The tip of a fixing pipe is preferably opened obliquely in consideration of driving into the ground, and similarly, the tip of an anchor unit integrated with the tip of a water collecting pipe is also planar. Is preferably formed in a V-shape, and in a side shape, it is preferably formed in a fan shape (stick shape) extending vertically. In addition, the drainage holes provided around the fixing pipe and the water collecting pipe are staggered in four rows in a pitch of 100 m in the axial direction.
m, it is preferable to penetrate in the range of 5 mm to 10 mm in diameter.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described by way of an embodiment. First, as shown in FIG.
m), while boring the casing pipe 1 to a predetermined depth (usually 50 m) while inserting the casing pipe 1 of the required number of pieces into the ground, and inserting the casing pipe 1 to the predetermined depth, an inner rod (not shown) Then, as shown in FIG. 3, the tip is cut obliquely and opened, and the outer periphery is arranged in four rows in a staggered manner with a pitch in the axial direction of 100 mm and a diameter of 10 mm.
1m long, 8 diameter with many drain holes 2 around
0 mm of the fixing pipe 3 is fixed to the casing pipe 1.
The fixing pipe 3 is protruded from the casing pipe 1 by a required length (may be the entire length) and is driven into the ground. Then, as shown in FIG. The drain holes 4 having a diameter of 5 mm smaller than the drain holes 2 and a pitch of 100 mm in the axial direction are formed in a zigzag manner. A required length (a required number of approximately 2 m-length anchored parts connected to a closed end, with a flat V-shaped end and a laterally shaped dovetail-shaped anchor body 5 projecting from the closed end) ), A water collecting pipe 6 having a diameter of 2 inches is inserted into the casing pipe 1, and the anchor 5 at the tip of the water collecting pipe 6 is driven into earth and sand filled inside the fixing pipe 3, and a negative dilatancy ( dilatancy
), The inside of the fixing pipe 3 (the fixing pipe 3
Between the inner surface of the anchor pipe 5 and the outer surface of the anchor body 5) and the outer periphery of the protruding portion of the fixing pipe 3 protruding from the casing pipe 1 are tightened. As shown in FIG. 1, a water collecting structure a is constructed. In this case, the fixing pipe 3 collects the groundwater into the drainage hole 2 and drains the water through the water collection pipe 6, so that the fixing pipe 3 is strongly tightened into the ground by the negative dilatancy as described above. Therefore, when the casing pipe 1 is removed, the casing pipe 1 does not come out together with the casing pipe 1 and a sufficient gap is formed between the casing pipe 1 and the water collecting pipe 6, so that the removal resistance is small. Only 1 is easily extubated.

[0008]

As described above, according to the present invention, the anchor at the tip of the water collecting pipe having a smaller diameter than the fixing pipe is driven into the fixing pipe which is driven ahead of the predetermined depth. The earth and sand filled inside the anchoring pipe and the earth and sand at the outer peripheral portion are tightened by negative dilatancy, and the anchoring pipe is firmly anchored on the ground, so that the equipment and power for fixing the water collecting pipe And the casing pipe can be easily removed, and the water collecting structure can be labor-saving and efficiently constructed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a water collecting structure a constructed by a water collecting method according to the present invention.

FIG. 2 is a longitudinal sectional view showing a state where the casing pipe 1 is inserted into the ground.

FIG. 3 is a longitudinal sectional view showing a relationship between a casing pipe 1 and a fixing pipe 3;

FIG. 4 shows an anchor 5 of a water collecting pipe 6 on a fixing pipe 3
FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing pipe 2 Drain hole 3 Fixing pipe 4 Drain hole 5 Anchor body 6 Water collecting pipe a Water collecting structure

──────────────────────────────────────────────────続 き Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E02D 3/10 101 E02B 11/00

Claims (2)

(57) [Claims] 1. A boring to a predetermined depth while inserting a casing pipe. When the casing pipe is inserted to the predetermined depth, an inner rod is withdrawn, and then a large number of drain holes are provided around the short pipe, and a short end having an open end is provided. A fixing pipe is inserted into the casing pipe, and a tip end of the fixing pipe projects from the casing pipe and is driven into a ground for a required length. Subsequently, a number of drain holes are formed inside the casing pipe. A water collecting pipe formed by projecting an anchor body at the closed end is inserted, and the anchor body at the end of the water collecting pipe is driven into earth and sand filled inside the anchoring pipe, and a negative dilatancy (di
latancy) is a water collecting method in which the sand between the inside of the fixing pipe and the outer periphery of the fixing pipe protruding from the casing pipe is tightened, and after the tightening is strengthened, the casing pipe is removed. 2. A short fixing pipe having a number of drain holes formed therearound, and having a leading end opened and disposed laterally beyond a predetermined depth of the ground, and an outer periphery of a long pipe body having a required length. And a water collecting pipe formed by driving a plurality of drain holes around the anchor and projecting an anchor projecting from the closed end into earth and sand filled in the fixing pipe.