JPH09328989A - Catchment pipe embedding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow catchment without requiring a number of catchment pipes to prevent the liquefaction of a sand ground. SOLUTION: A pilot pipe 12 is curvedly driven from a departure into a ground until its end arrives at a destination and a drill pipe 13 capped on the outside of the pilot pipe 12 is driven until its end arrives at the destination or the departure. A catchment pipe formed by winding a small pitch of wire rod on the outer periphery of a core material cylindrically arranged at a space is connected to the end of the drill pipe 13, the drill pipe 13 is pulled to the departure or the destination to draw the catchment pipe 1 into the ground and then the pilot pipe 12 is extracted.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for burying a water collecting pipe.

[0002]

2. Description of the Related Art As a method for preventing liquefaction of sand ground,
There is a method of driving a large number of steel sheet piles 31 provided with the water collecting portion 30 as shown in FIG. This is to dissipate excess pore water pressure in the ground caused by an earthquake by collecting water from the water collecting section 30.

On the other hand, as shown in (2) of FIG.
Rainwater and aquifer 33 that penetrate there to prevent the collapse of 2
As a method of draining the water accumulated in the above, there is a method of placing a large number of water collecting pipes 34 on the slope 32. Since it is difficult to ascertain the place where the aquifer 33 is present, a large number of water collecting pipes 34 are installed at appropriate intervals. Further, these water collecting pipes 34 are usually linear.

[0004]

However, the steel sheet pile provided with the water collecting portion of the above (1) has a very narrow water collecting range. Therefore, in order to prevent liquefaction over a wide area, a large number of steel sheet piles are hit. It had to be installed.

Further, as shown in (2), when draining the water accumulated in the aquifer to prevent the slope from collapsing, it is difficult to ascertain the location of the aquifer reliably, and therefore a large number of collections are required. I had to cast a water pipe. Furthermore, since the water collection pipe is straight, it is difficult to collect water at a specific location if there is an obstacle in the middle.

The present invention has been made in view of the above problems, and an object thereof is to provide a method of burying a curved water collecting pipe under an obstacle without requiring a large number of water collecting pipes. Is to provide.

[0007]

[Means for Solving the Problems] Means for solving the above-mentioned problems are as follows: a pilot pipe is dug in a curved shape from the starting side into the ground to make its tip reach the reaching side. After digging with a drill pipe on the outside and making the tip reach the reaching side or the starting side, wire rods were wound around the outer periphery of the core material arranged in a substantially cylindrical shape with a slight interval. The water collecting pipe is connected to the end of the drill pipe, the drill pipe is pulled toward the starting side or the reaching side to draw the water collecting pipe into the ground, and then the pilot pipe is pulled out.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. 1 (1) is a vertical cross-sectional view of the water collecting pipe, (2) is the same horizontal cross-sectional view, (3) and (4)
Is an enlarged sectional view of the wire rod, FIG. 2 is a perspective view of the water collecting pipe, and FIG.
It is a longitudinal cross-sectional view to which the water collection pipe of the book was connected.

The water collection pipe 1 used in the present invention has a core member 5 arranged in a substantially cylindrical shape between a front annular body 3 and a rear annular body 4 which are joints, and a spiral shape with a slight gap on the outer periphery thereof. It is composed of a wire 6 wound around.

The wire 6 has a triangular cross section, and is welded to the core 5 with a flat outer surface (bottom surface) 6a inclined inward (θ) with respect to the propelling direction in order to reduce the resistance of adhering soil during propulsion. . Water passage slits 7 are formed at a small interval between the wire rods 6 to prevent the inflow of earth and sand, and the water passage slits 7 are formed wide toward the inside so as not to be clogged even if the earth and sand enter. There is.

Therefore, it is difficult for the sediment particles to flow into the water collection pipe 1 from the water passage slit 7, and even if they flow in, the sand grains are gradually widened inward so that they are not clogged. Further, since the wire rod 6 is inclined (θ) inward with respect to the propelling direction, the propelling into the ground is smoothly performed.

The wire 6 may have an equilateral triangle, an isosceles triangle, an isosceles triangle, or the like, and may have a trapezoidal cross section or a circular cross section as shown in (4) of FIG.

A male screw 8 is provided on the outer peripheral surface of the front ring body 3 for jointing, and a female screw 9 is provided on the outer peripheral surface of the rear ring body 4, respectively. As shown in FIG. Is screwed into the female screw 9a of the other water collecting pipe 1a to be connected in an arbitrary number. It also allows mechanical connections other than welding and screws.

As described above, since the water collecting pipe 1 is constructed by spirally winding the wire 6 around the outer periphery of the core 5, the water collecting pipe 1 is easily bent in the longitudinal direction.

FIGS. 4 to 6 show the test results of the bending test and the tensile test of the water collecting pipe of the present invention and the vertical holed steel pipe and the horizontal holed steel pipe of the conventional water collecting pipe structure. The water collecting pipe of the present invention has a diameter of 318.5 mm, a wire interval of 1 mm, and a core material of 8 mm.
X 66, aperture ratio 25%, maximum cross-sectional area 33.2 cm
² (core material only), minimum cross-sectional area 33.2 cm ² (core material only)
It is. In (1), FIG. 5 and FIG. 6 of FIG. 4, solid lines are calculated values of bending deflection, bending stress and tensile elongation of the water collecting pipe of the present invention. For bending characteristics, the second moment of area can be calculated by considering only the core material, and the values can be used to estimate the amount of bending and the generated stress. In addition, the tensile property is estimated to be the core material alone, and the amount of elongation and the generated stress are estimated assuming that it bears the load.

The vertical perforated steel pipe is as shown in (2) of FIG. 4, and has a diameter of 318.5 mm, a hole shape of 100 mm in the pipe axis direction, a circumferential direction of 10 mm, an opening ratio of 2%, and a maximum cross-sectional area. The area is 69 cm ² and the minimum cross-sectional area is 65 cm ² . Further, the horizontal perforated steel pipe is as shown in (3) of the same figure.
18.5 mm, the shape of the hole is 10 mm in the tube axis direction, 100 mm in the circumferential direction, the aperture ratio is 2%, the maximum cross-sectional area is 69 cm ² , and the minimum cross-sectional area is 49 cm ² . 4 (1), 5 and 6
In, the dotted line is the vertical perforated steel pipe, and the alternate long and short dash line is the calculated value of the bending deflection, bending stress, and tensile elongation of the horizontal perforated steel pipe. The bending characteristics of these steel pipes have a cross-section of
The second moment is calculated, and the deflection and the generated stress are estimated using the calculated values. For tensile properties, the stress is calculated for each cross section (with and without holes), the amount of strain is calculated for each cross section, and the elongation for the entire length is calculated. The deformation of the holes and the influence of stress concentration are not considered.

According to the results of these tests, the bending flexures of the present invention are remarkably large, and the bending stress is not so large, although the three members have almost the same tensile elongation. That is, in bending, it bends more easily than a steel pipe of the same diameter, and the generated stress is not much different from that of a steel pipe bent by the same amount. That is, it has a characteristic that it bends well and is hard to break.

Next, a burying method using the water collecting pipe 1 as described above will be described with reference to FIGS. 7 and 8. Fig. 7 shows a water collecting pipe 1 for improving the foundation ground of existing structures such as buildings.
Is curved, that is, is drawn in from the ground surface on one side such as a tank or an existing building 18, passes through below and reaches the ground surface on the other side, and is buried.

First, as shown in (1), the pilot pipe 12 is advanced along a planned trajectory while excavating the ground 11 with the excavation bit 10 attached to the tip.

Each time the pilot pipe 12 digs a predetermined distance, the drill pipe 13 and the casing 14 on the outer side of the pilot pipe 12 are digged to reach the ground surface on the opposite side to dig the guide hole 14a. After excavating the guide hole 14a, the drill pipe 13 remaining therein is pulled toward the starting side and widened by the widening excavating bit 15 at the tip.

After the guide hole 14a is widened in this way, (3)
As shown in, the water collecting pipe 1 is attached to the tip of the drill pipe 13 remaining therethrough via the reamer 16 and the swivel joint 17. Then, while the drill pipe 13 is rotated and drawn in toward the starting side, the water collecting pipe 1 is drawn in without being rotated because of the swivel joint 17.

As described above, each time the water collection pipe 1 is pulled in, another water collection pipe 1a is sequentially added and the tip of the water collection pipe 1 reaches the ground surface on the starting side, so that the curved water collection pipe 2 is buried underground in the existing building 18 or the like. To be done. After the guide hole 14a is widened, the water collecting pipe 1 is attached to the tip of the drill pipe 13 remaining there and pulled in toward the starting side. May be.

Next, referring to FIG. 8, the water collecting pipe 1 is attached to the existing building 18
The method of burying by pushing from the ground surface on one side will be explained. First, the pilot pipe 1 is excavated while excavating the ground 11 with the excavation bit 10 attached to the tip as described above.
Digg 2 along the planned trajectory.

Next, each time the pilot pipe 12 digs a predetermined distance, the drill pipe 13 on the outer side of the pilot pipe 12 is moved forward, and the water collecting pipe 1 is pushed over the outer side.

Each time the water collecting pipe 1 is pushed in, another water collecting pipe 1a is added to the rear end portion to advance the drill pipe 13 as a guide, and the tip of the water collecting pipe 1a reaches the ground surface on the starting side. 2 is buried underground in the existing building 18 (see FIG. 9).

By embedding the curved water collecting pipe 2 in the ground requiring countermeasures against liquefaction, water can be collected over a wide area with a small number of obstacles while avoiding obstacles.

FIG. 10 shows an example in which the water collecting pipe 2 curved by the same method as described above is applied to the slope. Since the water collection pipe 2 curved in this way can be brought into contact with a plurality of aquifers 21 by itself, efficient and economical water collection can be performed.

The water collection pipe 2 of the present invention is not limited to the ground 11 or the slope 19 of the existing building 18 as described above, and it is buried while avoiding a place where water collection is necessary or an obstacle. It can be applied wherever that is necessary.

[0029]

According to the present invention, the number of the water collecting pipes can be reduced by bending the water collecting pipe having a good bending deformation characteristic and burying the water collecting pipe while avoiding obstacles, which is economical.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a buried pipe, FIG. 2 is a lateral sectional view of the buried pipe, and FIGS. 3 and 4 are enlarged sectional views of a wire rod.

FIG. 2 is a perspective view of a water collection pipe.

FIG. 3 is a cross-sectional view in which two water collecting pipes are connected.

[FIG. 4] (1) is a graph showing the deflection of a water collecting pipe, a vertical perforated steel pipe, and a horizontal perforated steel pipe, (2) is a front view of the vertical perforated steel pipe, and (3) is a horizontal perforated pipe. It is a front view of a steel pipe.

FIG. 5 is a graph showing stresses generated in a water collecting pipe, a vertical perforated steel pipe, and a horizontal perforated steel pipe.

FIG. 6 is a graph showing tension of a water collecting pipe, a vertical perforated steel pipe, and a horizontal perforated steel pipe.

7 (1) to (3) are cross-sectional views of a method of retracting and burying a water collecting pipe.

FIG. 8 is a cross-sectional view of a method of pushing in and collecting a water collecting pipe.

FIG. 9 is a cross-sectional view of a buried structure of a water collection pipe buried underground in an existing building.

FIG. 10 is a cross-sectional view of a buried structure of a water collection pipe buried on a slope.

FIG. 11 (1) is a perspective view of a steel sheet pile having a water collecting portion,
(2) is a cross-sectional view of a conventional buried structure of a water collecting pipe.

[Explanation of symbols]

 1 Water collecting pipe 2 Curved water collecting pipe 3 Front annulus 4 Rear annulus 5 Core material 6 Wire rod 7 Water passing slit 8 Male screw 9 Female screw 10 Drill bit 11 Ground 12 Pilot pipe 13 Drill pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Takeuchi 2-6-3 Otemachi, Chiyoda-ku, Tokyo Within Nippon Steel Corporation (72) Inventor Yuji Koshino 19 Nakahama-cho, Amagasaki-shi, Hyogo Hia Steel Industry Stock Company

Claims (3)

[Claims] 1. A pilot pipe is excavated from the starting side into the ground in a curved shape so that its tip reaches the reaching side, and a drill pipe is covered on the outside of the pilot pipe to proceed with the tip to reach the reaching side or the starting side. After reaching the side,
Connect a water collecting pipe in which wire rods are wound around the outer periphery of a core material arranged in a substantially cylindrical shape with a slight interval to the end of the drill pipe, and pull the drill pipe toward the starting side or the reaching side. The method for burying a water collecting pipe is characterized in that the water collecting pipe is pulled into the ground and then the pilot pipe is pulled out. 2. After the pilot pipe is dug in a curved shape from the starting side into the ground and the tip of the pilot pipe is made to reach the reaching side, a small amount of wire is attached to the outer periphery of the core material arranged in a substantially cylindrical shape with a gap. A method for burying a water collecting pipe, characterized in that the water collecting pipe is wound at regular intervals to cover the outside of the pilot pipe, propel it underground to bury it, and then pull out the pilot pipe from the water collecting pipe. 3. The method for burying a water collecting pipe according to claim 1, wherein the wire rod has a circular cross section, a triangular cross section, or a trapezoidal cross section, and is wound spirally around a core material.