JPH10317368A - Method for controlling underground water level using steel-pipe-column-line earth-retaining wall, and structure thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling the level of back underground water using a steel-pipe-column-line earth-retaining wall. SOLUTION: Steel pipes 1 each provided with a water hole 5 on its side making contact with back ground are connected together to construct a steel- pipe-column-line earth-retaining wall A, and a water-permeable layer B filled with crushed stones or the like is formed on the side of the wall A facing back soil D. The inside of each steel pipe 1 is dug to form a hollow pipe, in which a water distributing pipe 10 connected to a water injecting/draining pump 12 is installed. When the level of underground water in the back soil D is high, water flowing into the steel pipes 1 through the water-permeable layer B is discharged to prevent the rise of the underground water; when the level of the underground water is low, water is injected from the steel pipes 1 to supply the soil with underground water through the water-permeable layer B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a method for controlling a groundwater level and a structure thereof, wherein the groundwater level on the back ground can be maintained and adjusted by using a steel pipe column soil retaining wall to be formed.

[0002]

2. Description of the Related Art In order to perform excavation work in the construction of an underground structure or the like, a continuous retaining wall of reinforced concrete or a steel pipe column retaining wall is formed along the construction area. The construction of earth retaining walls often blocks groundwater veins around the construction area.In such cases, the groundwater level on the ground behind the earth retaining walls greatly increases and decreases, and the drainage worsens and the well water level rises, or It will adversely affect the surrounding environment, such as drought, well withering, and land subsidence. In particular, in recent years, this has become a social problem as the excavation work becomes larger.

Therefore, as a method for solving this problem,
Groundwater on the back ground side is provided by pumping up with a well on the back side of the retaining wall (dave well) or by providing a water-permeable frame with a water-blocking / water-permeable function in some places on the reinforced concrete retaining wall itself. And recharge the ground with groundwater.

[0004]

However, in the method using deep wells, etc., the cost for installing a well becomes large, and in the method of providing a water passage frame on the retaining wall, the construction is troublesome and the cost is large. Problem. In addition, in the case of a steel pipe column retaining wall, since a ready-made steel pipe is used, it is difficult to change its structure, which is unsuitable for this kind of structure.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and utilizes a steel column-column retaining wall having excellent proof strength and good workability, and using the steel pipes as pipes for collecting and draining groundwater. It is an object of the present invention to provide a highly economical method and its structure for adjusting the groundwater level such as vertical control and maintenance of the groundwater and restoring the groundwater flow by utilizing the above.

[0006]

The structure of the present invention will be described below with reference to the drawings corresponding to the embodiments. Steel pipes 1 having holes 5 are connected to each other to connect steel pipe column retaining walls A
Is formed on the back ground D side of the retaining wall A to form a permeable layer B filled with crushed stone or the like in contact with the retaining wall A, and excavate and discharge the inside of the steel pipe 1 of the retaining wall A. Then, the inside of the steel pipe 1 and the permeable layer B are communicated with each other through the water hole 5, and
The feature is that the groundwater level of the back ground D is adjusted through the permeable layer B by drainage.

Further, in the structure of the second aspect, a steel pipe column retaining wall A is formed by connecting steel pipes 1 provided with water holes 5 on a side contacting the rear ground D, and the rear side of the retaining wall A is formed. A permeable layer B filled with crushed stones or the like is formed in contact with the retaining wall A, and the inside of the hollow steel pipe 1 of the retaining wall A and the permeable layer B communicate with each other through the water hole 5. 1, a water distribution pipe 10 connected to a pouring / draining pump 12 is provided.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an embodiment of the structure of the present invention, and FIGS. 3 to 6 show the construction process. 7 and 8 show another embodiment,
9 and 10 show an embodiment of a steel pipe used.

The underground water level control structure of the present invention comprises a steel pipe column retaining wall A, a permeable layer B formed on the back ground D side thereof,
It consists of a water hole 5 for pouring and draining, which is installed in the steel pipe 1 of the retaining wall A.

[0010] Steel pipe column retaining wall (hereinafter referred to as retaining wall) A
Is formed in contact with an excavated ground C such as a construction site of an underground building. As shown in FIGS. 3 and 4, the steel pipes 1, 1 provided with the joint members 2 on the opposing outer surfaces are connected to each other by fitting the joint members 2, 2 to each other while connecting the steel pipes 1, 2 with each other. Formed in the excavation hole 4 filled with. This method is a conventionally known method called the ONS method, but the formation of the retaining wall A is not limited to the ONS method, and other conventionally known methods, for example, by hitting or digging a steel pipe sheet pile. It is also possible to use a construction method of forming by submerging.
In the present invention, as the steel pipe 1 of the retaining wall A, a steel pipe in which a required number of water holes 5 are provided on the side in contact with the back ground D, as shown in FIGS. Is done.
In this case, as shown in the figure, it is preferable to add a reinforcing plate 6 at a location where the water hole 5 is opened.

After the formation of the retaining wall A, a sheet pile wall 7 is placed on the back ground D at a required distance from the retaining wall A, substantially parallel to the retaining wall A. Then, as shown in FIGS. 5 and 6, the ground between the retaining wall A and the sheet pile wall 7 is excavated and excavated to form a filling space 8 such as crushed stone, and the water hole 5 of the steel pipe 1 is formed. Expose. In this case, in the case of the earth retaining wall method (ONS method) using soil cement, the soil cement 3 on the filling space side is left as it is in order to maintain the water stopping property of the joint portion 2 of the steel pipes 1, 1. I do.

Next, the filling space 8 is filled with a filtering material 9 such as crushed stone or gravel to form a water permeable layer B between the retaining wall A and the back ground D (see FIGS. 1 and 2). Then, the inside of each steel pipe 1 is excavated and excavated by a hammer grab or an auger, thereby forming the steel pipe 1 into a hollow pipe, and excavating and excavating the excavated ground C of the retaining wall A. After the formation of the water permeable layer B, the sheet pile wall 7 may be left as it is, or may be removed. When the sheet pile is left, it is necessary to make the sheet pile wall 7 porous so as not to hinder the flow of water between the back ground D and the permeable layer B.

FIGS. 1 and 2 show the inside of the hollow steel pipe 1.
As shown in the figure, a water supply / drainage pipe 10 is inserted and installed so that its lower end is located slightly above the bottom of the excavation. Each water pipe 10 is a ground-based injection / drainage pump
Connected to 12 water distribution mains 11. And note and drainage pump
The pipe 13 on the opposite side of the water distribution main pipe 11 is connected to required places and facilities such as rivers and reservoirs. The water distribution pipes 10 may be provided not every steel pipe 1, but every few pipes.

The structure of the present invention is constructed through the above-described construction process. Therefore, when the back ground D is on the upstream side of the groundwater flow or in a spring area, the groundwater on the back ground D infiltrates into the permeable layer B and flows into the steel pipe 1 from the water hole 5. And will be stored. In the present invention,
In such a case, the injection / drainage pump 12 is set on the drain side, and the water in the steel pipe 1 is sucked and drained. Thereby, the groundwater level of the back ground D is controlled.

Conversely, if the groundwater is interrupted by the retaining wall A, for example, when the back ground D is on the downstream side of the groundwater flow, the groundwater level will drop. In these cases,
Injection / drainage pump 12 pumps water from another location or water drained from the opposing upstream side into water pipe 10 into steel pipe 1. Thereby, the water in the steel pipe 1 flows into the permeable layer B from the permeable hole 5 and permeates from the permeable layer B to the back ground D. Thereby, the water level of the back ground D can be recovered.

It is necessary that the groundwater level of the back ground D is not changed unnecessarily. for that purpose,
The water level stored in the steel pipe 1 is measured, and the injection / drainage amount by the water distribution pipe 10 is adjusted so that the required water level is always obtained. Adjustment of the pouring / draining can be performed by manually or automatically switching the pouring / draining pump 12 by visually checking the water level in the steel pipe 1 or providing a measuring device in the steel pipe 1.

As shown in FIG. 7, a filter medium 9 such as crushed stone or gravel can be filled in the steel pipe 1 of the retaining wall A.
Then, when draining, the sediment mixed with the water flowing into the steel pipe 1 from the water permeation hole 5 is filtered to help clogging of the water distribution pipe 10 and protection of the operation of the injection / drainage pump 12. become. In that case, in order to protect the water distribution pipe 10, a small-diameter casing 14 is provided, and the water distribution pipe 10 is inserted therein. If the inner surface of the steel pipe 1 to be used is rust-proof, it is preferable to apply a process such as a protection net (not shown) to the inner surface to protect the inner surface.

In the above embodiment, the permeable layer B is provided over the entire surface of the retaining wall A in the longitudinal direction.
For example, as shown in FIG. 8, the permeable layer B can be provided in a fragmentary manner at intervals in the longitudinal direction of the retaining wall A.

[0019]

As described above, according to the present invention,
The steel pipe of the steel column pillar retaining wall is used as a water storage pipe, a permeable layer is formed on the back of the retaining wall, and water is injected into the back ground or discharged from the ground by means of pouring and draining means provided on the steel pipe. In addition to the easy construction, excellent strength and waterproof properties, the steel pipe column soil retaining wall, which was previously unsuitable for adjusting the groundwater level and restoring the groundwater flow, can be used. Collecting groundwater from the ground,
The groundwater level can be freely and effectively controlled, such as discharging and recharging the groundwater at the rear, and adverse effects on the surrounding environment due to fluctuations in the groundwater level due to excavation work can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the structure of the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a longitudinal sectional view showing a state in which a steel pipe column retaining wall is formed and a sheet pile wall is driven.

FIG. 4 is a plan view of the same.

FIG. 5 is a longitudinal sectional view showing a state where a filling space is excavated and formed.

FIG. 6 is a plan view of the same.

FIG. 7 is a longitudinal sectional view showing another embodiment of installation of a water distribution pipe.

FIG. 8 is a plan view showing another embodiment of forming a water-permeable layer.

FIG. 9 is an enlarged vertical sectional view of a steel pipe.

FIG. 10 is a rear view of the main part.

[Explanation of symbols]

 A Steel pipe pillar row retaining wall B Water permeable layer C Drilling side ground D Back ground 1 Steel pipe 2 Joint material 3 Soil cement 4 Drilling hole 5 Water flow hole 7 Sheet pile wall 8 Filling space 9 Filtering material 10 Water pipe 12 Injection / drain pump 14 Casing

Claims (2)

[Claims] A steel pipe having a water column formed on the side in contact with the back ground to form a steel pipe column retaining soil wall. Is formed, and the inside of the steel pipe of the retaining wall is excavated and excavated, and the inside of the steel pipe and the permeable layer are communicated with each other through the water hole, and the permeable layer is poured and drained from the steel pipe side. A method of controlling a groundwater level using a steel tube column retaining wall, comprising adjusting a groundwater level of a back ground through a tunnel. 2. A steel pipe column retaining wall is formed by connecting steel pipes provided with water holes on a side in contact with the back ground, and a crushed stone is filled on the rear side of the retaining wall in contact with the retaining wall. That the permeable layer was formed, and the inside of the steel pipe having the hollow retaining wall was communicated with the permeable layer through the water hole, and a water distribution pipe connected to an injection / drainage pump was installed in the steel pipe. Characterized by a groundwater level control structure using steel pipe column retaining walls.