JP6514975B2 - Waterway construction method - Google Patents

Description

The present invention relates to a construction how water passages.

When landslides occur along rivers such as mountain areas, rivers may be blocked by earth and sand, and so-called natural dams may be formed. If a natural dam is formed, a reservoir will be formed upstream of the natural dam.
In such a natural dam, when the water level rises due to heavy rain etc., the reservoir water (river water) overflows the bank body and there is a risk that the natural dam may collapse as it erodes. If a natural dam collapses, it may flow out as a debris flow and cause disasters in the downstream area.
In order to prevent disasters in the downstream area when natural dams are formed, it is necessary to either remove the natural dams (sedged sediments) or drain the upstream water so that the natural dams will not be destroyed. is there.

However, it takes time and money to remove the natural dam formed in the mountainous area.
On the other hand, although the drainage method using a submersible pump is common as a drainage method of the water of the upper stream side of a natural dam, while operation of a submersible pump requires electric power, maintenance takes time and effort.

Therefore, according to Patent Document 1, as a structure for draining the water on the upstream side of the natural dam to the downstream side, a plurality of block materials having through-holes in advance in the riverbank, riverbed or slope of the river are made continuous. The method of securing a water flow passage is disclosed by arrange | positioning.
Patent Document 2 discloses a method of draining water on the upstream side of a natural dam by forming a drainage path covered with a ground improvement body in the natural dam. In addition, many convex parts are formed in the roadbed of the drainage path, and scooping is prevented by decelerating the speed of the flowing sewage.
Furthermore, Patent Document 3 discloses a method of draining stored water on the upstream side of a natural dam using a siphon drainage system.

JP, 2006-188847, A JP, 2014-037679, A JP, 2014-163202, A

The block material of Patent Document 1 needs to be installed in advance before the natural dam is formed, and can not be adopted as a countermeasure after the natural dam is formed.
Since the drainage channel of Patent Document 2 is formed at the upper part of a natural dam, it is necessary to pump up with a submersible pump or the like in order to drain stored water. Therefore, power is required to operate the pump.
The drainage system of Patent Document 3 also needs to drive a pump for priming siphon, and power for that is required.

From this point of view, the present invention includes a aims to propose a construction how possible and the water passage forming a drainage like that does not require power, etc. by forming a water passage in the ground Do.

In order to solve the above-mentioned subject, the construction method of the water flow passage of the present invention excavates a ground using an auger screw and arranges a casing on the ground, and a pipe for water passage reaching the water is obtained. Forming a pipe, forming a pipe plug for closing the casing at a tip end of the auger screw in a state where the excavated soil is accumulated in the casing, and collecting the auger screw It is characterized by having.
In addition to the construction to a natural dam, the method of construction of a water passage of the present invention is applicable to the construction of a water passage connected to the sea, a lake, a pond, a river or the like.

According to the construction method of the water flow path, since the water flow path connected to the water in the state where the excavated soil is accumulated in the casing is formed, the construction is not hindered by the spring water, and thus the construction can be simplified. it can.
If, for example, a water passage is formed in a natural dam according to the construction method of the water passage, drainage from the upstream side to the downstream side becomes possible without requiring a pump or the like.

Further, when connecting a T-shaped pipe having two branch pipes to the base end of the casing, the auger screw is recovered from one branch pipe to close the one branch pipe with the pipe plug. If the other branch pipe is drained, the auger screw can be recovered easily and safely.
In addition, when it is difficult to form a pipe plug due to the presence of the excavated soil accumulated in the casing, the tip of the auger screw is made to project into water before the pipe plugging step, and the tip of the auger screw is made After washing the part, a washing step may be performed to put the auger screw back into the casing.

According to construction how the water passage of the present invention, it is possible to form a drainage channel like that does not require power or the like.

It is a sectional view showing a drainage channel concerning an embodiment of the present invention. (A)-(c) is a fragmentary sectional view which shows the construction condition of the construction method of the water flow path which concerns on embodiment of this invention. (A)-(c) is a fragmentary sectional view which shows the construction condition following FIG.2 (c).

As shown in FIG. 1, the water drainage / drainage channel 1 of the present embodiment is a pipeline that penetrates the natural dam 2 from the downstream side to the upstream side.
The drainage channel 1 is a water passage intended to drain the water stored on the upstream side of the natural dam 2. Although the water drainage and drainage path 1 of this embodiment is formed substantially horizontally, the water drainage and drainage path 1 may have a slope.
The natural dam 2 is formed by sediment deposited by occurrence of landslide caused by heavy rain, earthquake, eruption and the like along rivers and valleys such as mountain areas. That is, the natural dam 2 is a levee formed naturally so as to occlude rivers and valleys by sediments such as earth and sand. When the natural dam 2 is formed, rainwater and river water are stored upstream of the natural dam 2 to form the reservoir 3.

Hereinafter, the formation method of the water flow path for forming the drainage channel 1 is demonstrated.
The formation method of the water flow path of this embodiment is provided with the pipe formation process, the washing process, the pipe plug process, and the recovery process.
The pipeline forming step is a step of digging the ground (natural dam 2) using the auger screw 4 and disposing the casing 5 on the ground as shown in FIG. 2 (a). In this embodiment, as the excavating method of the natural dam 2, the same method as the excavating method applied to a so-called pipe roof method is performed, but the excavating method is not limited.

Drilling work on the natural dam 2 is performed until the auger screw 4 reaches the water on the upstream side (reservoir 3) of the natural dam 2.
In the present embodiment, both ends of the casing 5 are made to project from the downstream slope and the upstream slope of the natural dam 2. That is, the casing 5 of the present embodiment forms a conduit (water flow passage) that reaches the water upstream of the natural dam 2 from the downstream side of the natural dam 2. In addition, the both ends of the casing 5 should just be opened in the downstream slope of the natural dam 2, or an upstream slope, and it is not necessary to necessarily protrude from both slopes.
In addition, if reinforcement processing (for example, chemical solution injection) is performed in advance with respect to the planned arrival point of the auger screw 4, it is possible to prevent the periphery of the auger screw 4 from being eroded when the auger screw 4 reaches. As the reinforcement processing method, for example, a method of ground improvement from the upper part of the natural dam 2 or a method of injecting a chemical solution with an injection pipe previously provided around the casing may be performed.

The washing step is a step of washing the tip (upstream end) of the auger screw 4.
To clean the tip of the auger screw 4, as shown in FIG. 2 (b), the tip of the auger screw 4 is protruded from the natural dam 2 (casing 5) into the reservoir 3 to rotate the auger screw 4 in water. Do it by
After the auger screw 4 has been cleaned, the auger screw 4 is drawn into the casing 5 (see FIG. 2 (c)).
The washing step may be omitted as long as the tube plug 7 can be formed without washing the auger screw 4.

The tube plugging step is a step of closing the casing 5.
The closing of the casing 5 is performed by forming a pipe plug 7 for closing the casing 5 at the tip of the auger screw 4 in a state where the excavated soil 6 is accumulated in the casing 5 as shown in FIG. .
In the present embodiment, at the tip of the auger screw 4, the pipe plug 7 is formed by inflating a rubber tube previously loaded in the rod of the auger screw 4. When the rubber tube is expanded by press-fitting a fluid such as gas or liquid into the inside of the rubber tube, the gap between the rod of the auger screw 4 and the inner peripheral surface of the casing 5 is closed. In addition, the formation method of the pipe | tube plug 7 is not limited, For example, a multiple pipe | tube is employ | adopted as a rod of the auger screw 4, and a chemical | medical solution material, a polymer type filler, cement type mortar etc. It may be formed by injecting a hardening agent of

The recovery step is a step of recovering the auger screw 4.
The auger screw 4 is recovered by pulling out from the proximal end (downstream end) of the casing 5 together with the pipe plug 7 and the excavated soil 6 in the casing 5 as shown in FIG. 3 (a).
In addition, as shown in FIG. 3B, a T-shaped pipe 10 provided with two branch pipes 8 and 9 is connected to the base end portion of the casing 5. One branch pipe 8 is piped coaxially with the casing 5, and the other branch pipe 9 is piped so as to intersect the axis of the casing 5. In the present embodiment, the inner diameters of the branch pipes 8 and 9 are the same as the inner diameter of the casing 5, but the inner diameters of the branch pipes 8 and 9 may be smaller or larger than the inner diameter of the casing 5. Good. Further, the branch pipes 8 and 9 may have different inner diameters.

The auger screw 4 is recovered through one branch pipe 8. When the distal end of the auger screw 4 is disposed inside one branch pipe 8, the one branch pipe 8 is closed by the pipe plug 7. When the excavated soil 6 and the like in the casing 5 are removed with the backward movement of the auger screw 4, the water W may flow from the reservoir 3 into the casing 5. The water W in the casing 5 is drained from the other branch pipe 9.
When one of the branch pipes 8 is closed by the pipe plug 7, as shown in FIG. 3C, the branch pipe 8 is shielded by a shielding member 11 such as a shutter. The configuration of the shielding member 11 is not limited. After the branch pipe 8 is shielded, the auger screw 4 (pipe plug 7) is removed from the inside of the branch pipe 8 and the lid 12 is installed at the pipe port of the branch pipe 8.

  According to the drainage and drainage channel 1 of the present embodiment, the water in the reservoir 3 can be drained to reduce the risk of collapse of the natural dam 2. In addition, since drainage is performed by natural flow, it is possible to reduce the time and cost required for maintenance and management of the pump and the like without requiring the pump and the like. Furthermore, efficiently draining the water of the reservoir 3 makes it possible to reduce the time and cost required for removing the natural dam 2.

Moreover, according to the construction method of the water flow passage of the present embodiment, since the water flow passage connected to the water in the state where the excavated soil 6 is accumulated in the casing 5 is formed, the construction is not hindered by the spring water. Drainage drainage channel (water flow passage) 1 can be constructed.
Further, since the auger screw 4 is recovered using the T-shaped pipe 10 provided at the downstream end of the casing 5, the auger screw 4 can be recovered easily and safely.
In addition, by forming the tube plug 7 after cleaning the auger screw 4, the tube plug 7 in close contact with the inner surface of the casing 5 can be formed.

As mentioned above, although embodiment of this invention was described, this invention is not limited to above-mentioned embodiment, About each said component, in the range which does not deviate from the meaning of this invention, it can change suitably.
For example, although the said embodiment demonstrated the case where a water flow path was formed in the natural dam 2, the construction method of the water flow path of this invention is applied also to construction of the water flow path connected to the sea, a lake, a pond, a river etc. You may
Further, the arrangement, the number, the inner diameter, and the like of the drainage drainage channel 1 provided in the natural dam 2 are not limited, and may be determined as appropriate.
Also, the T-shaped tube 10 may be piped as needed, and is not necessarily installed.
Moreover, although the said embodiment demonstrated the case where a washing | cleaning process was provided, a washing | cleaning process may be implemented as needed. For example, when the pipe plug 7 can be formed without being affected by the excavated soil 6 in the casing 5, the excavated soil 6 in the casing 5 may be formed by a chemical injection material, a polymer filler, a cement mortar or the like. In the case where the tube plug 7 is formed by curing, etc., the washing step may be omitted.

1 drainage drainage (water passage)
Reference Signs List 2 natural dam 3 reservoir 4 auger screw 5 casing 6 excavated soil 7 pipe plug 8, 9 branch pipe 10 T-shaped pipe

Claims (3)

A pipe forming step of forming a water passage for reaching the water by excavating the ground using an auger screw and arranging the casing on the ground;
A pipe plug process for forming a pipe plug for closing the casing at a tip end portion of the auger screw in a state where excavated soil is accumulated in the casing;
And a recovery step of recovering the auger screw.   A T-shaped pipe provided with two branch pipes is connected to the base end of the casing, and by collecting the auger screw from one branch pipe, the one branch pipe is closed by the pipe plug, The method for constructing a water passage according to claim 1, wherein the other branch pipe is drained.   Before the plugging step, the tip of the auger screw is protruded into water to wash the tip of the auger screw, and then the auger screw is returned to the inside of the casing. The construction method of the water flow path according to claim 1 or claim 2.

Images