JP2005330769A - Structure and construction method of water passing earth retaining wall - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure and a construction method of a water passing earth retaining wall 1 recovering its function when the passing capacity of underground water is lowered by clogging caused by use for many years, without intercepting the flow of underground water in a stage of constructing the earth retaining wall 1 before the completion of an underground structure and further in a stage of open-cutting in progress, not to mention after the completion of the underground structure. <P>SOLUTION: The structure of the water passing earth retaining wall is composed of a water passing vertical hole 2 excavated in the ground, and a water passing cylinder 21 installed inside the water passing vertical hole 2. The water passing cylinder has an outer diameter smaller than the inner diameter of the water passing vertical hole 2 and has water passing holes 22 opened. A water passing material 25 is filled between the water passing vertical hole 2 and the water passing cylinder 21, and a blocking plate 26 is inserted in the water passing cylinder 21 to block part of the water passing holes 22 of the water passing cylinder 21. A cut-off plate 3 is installed between the adjacent water retaining walls 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to the structure and construction method of a water retaining wall.

When constructing an underground structure such as a basement of a building or a subway, a retaining wall is constructed in advance on both sides of the excavation site.
By constructing this retaining wall, it is expected that the groundwater flow will be cut off and the downstream groundwater level will be lowered.
In order to solve such a problem, several countermeasures have been developed in the past.
JP-A-6-49839 Japanese Patent Laid-Open No. 7-224420 JP-A-11-81301 JP 2000-64270 A JP 2000-186336 A

The conventional water retaining wall structure and construction method described above have the following problems.
<I> The retaining wall already blocks the flow of groundwater at the stage of construction of the retaining wall before excavation. Many of the conventional methods for constructing retaining walls often block the flow of groundwater at the stage of constructing the retaining wall, even though the flow of groundwater after excavation has been secured.
<B> When used over a long period of time, it is expected that the water flow function is lowered due to the flow of groundwater, but it is difficult to recover the lowered flow again with the conventional structure.
<C> A method for providing another well on the back of the retaining wall as in a certain construction method requires a site for that purpose, and it is difficult to adopt it especially in urban areas where it is difficult to secure the site.

The structure of the water retaining wall of the present invention that solves the problems of the conventional apparatus as described above is the structure of the water passage vertical hole excavated in the ground and the water passage vertical hole installed inside the water passage vertical hole. A water pipe having an outer diameter smaller than the inner diameter, having a water passage hole, a water passage vertical hole, a water passage material filled between the water pipes, and a water pipe inserted into the water pipe. A plate body that is installed between a blocking plate that partially closes a water passage hole, a water passage vertical hole, and a retaining wall adjacent to the water passage vertical hole, and part of the water passage vertical hole The cross section is characterized by the structure of a water retaining wall in which another part is constituted by a water stop plate located in the cross section of the adjacent retaining wall.
In the construction method of the water retaining wall of the present invention, a water passage vertical hole is drilled between the retaining wall and the retaining wall, and the inside of the water passage vertical hole is smaller than the inner diameter of the water passage vertical hole. A water pipe having a diameter and having a water passage hole is installed, a water passage material is filled between the water passage vertical hole and the water pipe, and a blocking plate is inserted inside the water pipe. A part of the water passage hole is closed, and between the water passage vertical hole and the earth retaining wall adjacent to the water passage vertical hole, a part of the water passage hole is inserted in the cross section of the water passage vertical hole. It is characterized by a construction method of a water retaining wall, in which a water stop plate is installed and constructed so as to be located in a cross section of an adjacent retaining wall.
In the construction method of the water retaining wall of the present invention, before the excavation work is started, the retaining wall is installed on the side of the excavation position, and a water passage vertical hole is formed between the retaining wall and the next retaining wall. Drilling holes between the water passage vertical hole and the retaining wall adjacent to the water passage vertical hole, a part is in the cross section of the water vertical hole and the other part is in the cross section of the adjacent retaining wall. A water stop plate is installed so that the water flow vertical hole is located inside the water flow vertical hole and has an outer diameter smaller than the inner diameter of the water flow vertical hole and the water flow hole is opened. A water-permeable material is filled between the vertical hole and the water pipe, and the passage of the ground water is allowed through the water-permeable material and the water-hole of the water pipe. A blocking plate is inserted on the inside of the excavation side to block a part of the water passage hole of the water pipe, and the groundwater accumulated in the water pipe is pumped up and poured into the ground at a place beyond the cutting place. At the completion of excavation Is characterized by the construction method of a water retaining wall, in which groundwater accumulated in a water pipe is injected into the ground at a location beyond the excavation site through a water channel provided inside the excavation part. .
In the construction method of the water retaining wall of the present invention, before the excavation work is started, the retaining wall is installed on the side of the excavation position, and a water passage vertical hole is formed between the retaining wall and the next retaining wall. Drilling holes between the water passage vertical hole and the retaining wall adjacent to the water passage vertical hole, a part is in the cross section of the water vertical hole and the other part is in the cross section of the adjacent retaining wall. A water stop plate is installed so that the water flow vertical hole is located inside the water flow vertical hole and has an outer diameter smaller than the inner diameter of the water flow vertical hole and the water flow hole is opened. Fill the water pipe between the vertical hole and the water pipe and allow the water pipe to pass through the water hole of the water pipe and the water pipe. During the excavation work and when excavation is completed, Insert a blocking plate on the excavation side inside the water pipe to close a part of the water passage hole in the water pipe, and pump the ground water accumulated in the water pipe into the ground at a place beyond the cutting place. To note And carried out, in which features a method of constructing the water passing earth retaining walls.

Since the structure and construction method of the water retaining wall of the present invention are as described above, the following effects can be obtained.
<I> Even if the retaining wall is constructed, the construction does not block the flow of groundwater, and its high water flow capacity can be secured.
<B> The flow of groundwater will not be interrupted even after the construction of the retaining wall prior to the completion of the underground structure and at the stage where excavation is in progress.
<C> When clogging occurs due to long-term use and the water flow capacity of groundwater decreases, the inside of the water pipe remains hollow, so by performing maintenance such as supplying jet water from the ground, The water flow function can be restored.
<D> Since a water flow function can be provided on a part of the retaining wall itself, that is, on the line of the retaining wall, a separate water well is provided behind the retaining wall as in some conventional methods. This is not necessary and can be easily adopted even in urban areas where it is difficult to secure land.
<E> There is a possibility that soil cement on the retaining wall may flow into the impervious part, as in some conventional methods, because it is not in direct contact with the adjacent retaining wall for imperviousness. There is no need to remove or remove the soil cement. For this reason, the soil cement does not lower the water flow capacity, and a high water flow capacity can be secured.
<F> It is not a structure in which a special instrument is inserted into the hole as in some conventional methods, but a water passage is formed by filling a water passage material between the water passage vertical hole and the water passage. Therefore, there is a margin in the accuracy of drilling, and a high water flow capacity can always be ensured.

  Embodiments of the structure and construction method of a water retaining wall according to the present invention will be described below with reference to the drawings.

<1> Overall configuration.
The structure of the water retaining wall of the present invention is configured by providing a water passing part in a part of the retaining wall which is a non-water passing part.
As the retaining wall, not only a structure in which column-shaped water-stopping columns are continuously formed in the ground but also a retaining wall provided with a sheet pile and a steel pipe sheet pile can be used.
Below, the structure of a water flow part is demonstrated using the retaining wall comprised by the column row method as an example.

<2> Drilling.
The retaining wall 1 is a continuous wall body that is constructed in advance underground before the excavation range before excavating the ground.
The retaining wall 1 has a water-impermeable function that does not allow water to pass through, and is required to prevent water from passing to the cut-off side.
The non-water-permeable retaining wall 1 is constructed by various known methods known by names such as the SMW method.
Since a series of retaining walls 1 are constructed for each of a plurality of units by any of the construction methods, a water passage vertical hole 2 for forming the structure of the present invention is drilled between the units.
Therefore, the water flow vertical hole 2 is constructed as a part of the retaining wall 1 on the line of the retaining wall 1.
In addition, when there is room in the site, the position of the drilling hole can be shifted to the non-cutting side rather than on the line of the retaining wall 1. (Fig. 12)
Then, the water stop board installed between the water flow vertical hole 2 and the adjoining earth retaining wall 1 spreads in a square shape.
As a result, the water collection range can be expanded, and the drilling interval of the water flow vertical holes 2 can be increased, which is economical.
Furthermore, if it is such a drilling pattern, the space | interval of the stress bearing material like H steel installed in the retaining wall 1 adjacent to the water flow vertical hole 2 can be narrowed, and it is economical also from this point. .

<3> Installation of water pipe 21.
A water flow cylinder 21 is inserted and installed in the water flow vertical hole 2.
The water pipe 21 is a cylinder body having an outer diameter smaller than the inner diameter of the water flow vertical hole 2 and having the water hole 22 opened.
The water passage hole 22 is opened so as to be positioned on the cut-out side and the back surface on the opposite side when the water passage 21 is inserted.
Further, guide plates 23 are provided on the side surfaces on both sides of the water pipe 21 in the vertical direction. In the embodiment, an example of a C-shaped configuration in plan view is shown as the guide plate 23, but a shape adopted at the edge of a commercially available sheet pile and other known joint structures can be used.
Further, an expansion bag 24 that is long in the vertical direction is attached to both sides of each guide plate 23.

<4> Filling with water-permeable material 25.
There is a space between the water flow tube 21 and the water flow vertical hole 2.
Therefore, the inside of the inflatable bag 24 is filled with mortar or the like and inflated, and is in close contact with the hole wall of the water passage vertical hole 2 to form a partition.
Then, the water-permeable material 25 is filled in the gap between the cut-out side and the back side of the water-flow tube 21 surrounded by the expanded expansion bag 24.
This water-permeable material 25 can use a normal aggregate.
In order to secure the position of the expansion bag 24 so that the position of the expansion bag 24 does not move due to the filling of the water flow material 25, a steel material is disposed between the expansion bag 24 and the expansion bag 24.
By filling the water flow material 25, the groundwater flowing from the back surface of the water flow vertical hole 2 enters the water flow vertical hole 2, passes through the water flow material 25 and the water flow hole 22 of the water flow tube 21, and passes through the water flow tube 21. And flow out downstream through the water-passing material 25 on the cut-off side.
Thus, even if the water passage vertical hole 2 is constructed in the ground, the phenomenon of blocking the flow of groundwater does not occur.

<5> Connection with the retaining wall 1.
In the portion other than the water flow vertical hole 2, the retaining wall 1 is ensured to be non-water-permeable.
Therefore, a water stop plate 3 is installed in the vertical direction between the water flow vertical hole 2 and the earth retaining wall 1 adjacent to the water flow vertical hole 2.
The water blocking plate 3 is installed such that a part thereof is located in the cross section of the water vertical hole 2 and the other part is located in a cross section of the adjacent earth retaining wall 1.
At the time of installation, before the soil cement of the adjacent retaining wall 1 is hardened, the water stop plate 3 is forcibly pressurized and pressed from the ground.
At the time of press-fitting, the end of the water stop plate 3 on the water flow vertical hole 2 side is guided along the guide plate 23 of the water flow tube 21, so that the press-fitting direction does not deviate.
In addition, in the actual construction, the construction position of the retaining wall 1 and the position of the water passage vertical hole 2 cannot always be constructed accurately.
Even in that case, in the structure of the present invention, the retaining wall 1 and the water passage vertical hole 2 are connected by the water stop plate 3, and there is a margin in the position of the end portion of the water stop plate 3 on the side of the retaining wall 1. Even if there is a construction error, the construction can be easily absorbed by the water stop plate 3.
In addition, it is mentioned later about the construction in case it is a gravel layer etc. and insertion of the water stop board 3 is difficult.
An injection pipe for injection of mortar or the like is attached to the end of the water stop plate 3 on the water passage vertical hole 2 side, and mortar or cement milk is injected through this pipe when the water stop plate 3 is press-fitted.
As a result, the space between the inflatable bag 24 and the inflatable bag 24 is filled with mortar, and the end portion of the water blocking plate 3 is allowed to exist and is cured.

<6> Water flow state before excavation. (Fig. 5)
By constructing the water passage vertical hole 2 and the retaining wall 1 as described above, the water passage vertical hole 2 for maintaining water permeability and the water-impermeable retaining wall 1 are integrated.
Therefore, before excavation of the ground, the flow of groundwater is blocked at the position of the retaining wall 1, but the flow from the upstream to the downstream can be maintained only at the position where the water passage vertical holes 2 are installed.

<7> When the water stop plate 3 cannot be press-fitted.
When the water stop plate 3 such as a gravel layer cannot be easily press-fitted, a sand column is provided between the earth retaining wall 1 and the water passage vertical hole 2.
Therefore, a sand pillar hole is drilled between the retaining wall 1 and the water passage vertical hole 2, and the sand in the hole is filled.
When installing the water stop plate 3, pass a part of the water stop plate 3 in the cross section of the water vertical hole 2, the other part in the soil cement not yet solidified in the adjacent earth retaining wall 1, and the middle Install so that it is located inside the sand column.

<8> In the case of sheet pile retaining wall 1. (Fig. 10)
When the earth retaining wall 1 is configured by a sheet pile, a similar water stop effect can be obtained by inserting a joint at the edge of the sheet pile into the guide plate 23 outside the water pipe 21.
In this case, the sheet pile inserted into the guide plate 23 also serves as the water stop plate 3 of the present invention.

<9> Block water flow. (Fig. 6)
After the excavation between the retaining walls 1 starts, inflow of groundwater into the excavation part must be prevented.
Therefore, prior to the excavation work, the water passage hole 22 on the excavation side of the water conduit 21 is closed.
Specifically, a guide groove 27 may be provided in the longitudinal direction inside the water flow tube 21, and the closing plate 26 may be inserted along the guide groove 27. A seal for water stop is attached to the slide surfaces of the guide groove 27 and the closing plate 26.
In order to completely block water flow, a pipe for mortar injection is attached to the water flow material 25 side of the blocking plate 26, and the mortar is injected into the water flow material 25 through this pipe. In this way, water stoppage from the water passage vertical hole 2 to the cut side is ensured.
Instead of the blocking plate 26, as shown in FIG. 11, the rectangular tube 4 having a circular wall plate 41 in part is inserted into the water tube 21. Then, the square tube 4 can be rotated to close the water passage hole 22 toward the arc-cut wall plate 41 through the cut side of the water tube 21.
Or the circular arc plate can be slidably installed in the circumferential direction on the inner surface of the water flow tube 21, and the water flow hole 22 of the water flow tube 21 can be closed by an operation of pulling and closing the sliding door.
Alternatively, the arc plate can be slidably installed on the inner surface of the water pipe 21 so as to be slidable in the vertical direction, and the water hole 22 of the water pipe 21 can be closed by an operation of pulling it downward.

<10> Pumping up groundwater.
As described above, if the clogging plate 26 is inserted into the excavation side inside the water pipe 21 before the excavation work is started and a part of the water passage hole 22 of the water pipe 21 is blocked, the groundwater is It cannot flow to the cut-off side and is blocked there.
For this purpose, the groundwater accumulated in the water pipe 21 is pumped up by the pump P.
A similar water pipe 21 provided on the opposite side of the cut surface 5 passes water, and water is poured into the ground from the water pipe 21 at a position beyond the cut place.
Thus, the groundwater flow is not interrupted during the excavation work.

<11> At the completion of excavation. (Fig. 7)
When the excavation is completed and the bottom of the excavation is reached, the water channel 6 is provided at the bottom of the excavation.
The water channel 6 can be a known one such as a concrete tube.
If pumping by the pump P is stopped, the groundwater accumulated in the water pipe 21 can be poured into the ground at a location beyond the excavation site through the water channel 6 provided at the bottom of the excavation.

<12> Construction of underground structures. (Fig. 8)
When excavation is completed to the planned depth, the underground structure 7 is constructed thereafter.
In this case, if the water channel 6 is disposed at the bottom of the excavation, the water channel 6 on the lower surface of the structure 7 can be used as a groundwater channel as it is.

<13> When passing water inside the excavation part. (Fig. 9)
In addition, as shown in FIG. 9, the position of the underground structure 7 may be deep and the range of groundwater may be higher than the underground structure 7. FIG.
In that case, the water channel 6 is not constructed at the bottom of the excavation, but the water channel 6 is constructed at the upper part of the underground structure or in the structure.
Then, the water can be passed through the inside of the excavation part and the inside of the structure.
That is, the position where the water channel 6 is installed is not limited to the bottom of the excavation part, and can be installed anywhere inside the excavation part as long as the depth is equal to or lower than the water level of groundwater.

<14> Cleaning of the water passing material 25.
It is also conceivable that the water flow capacity of the water flow material 25 decreases due to long-term use.
In that case, since the inside of the water flow cylinder 21 is maintained in an open state, various maintenance can be performed such as cleaning the water flow material 25 by inserting a jet nozzle from the open portion.

Explanatory drawing of the Example of the water flow cylinder 21 which comprises the water flow retaining wall 1 of this invention. Explanatory drawing of the state installed in the water flow vertical hole 2 of the water flow pipe 21. FIG. Explanatory drawing at the time of connecting the water flow vertical hole 2 and the earth retaining wall 1 in a water stop state. Explanatory drawing of the state which interrupted | blocked the water flow function of the water flow pipe. Explanatory drawing of the water flow state of groundwater before excavation. Explanatory drawing of the water supply state of groundwater under excavation. Explanatory drawing of the water supply state of groundwater when excavation is completed. Explanatory drawing of the water supply state of groundwater when an underground structure is completed. Explanatory drawing of the other Example of the water supply state of groundwater when an underground structure is completed. Explanatory drawing of the Example which uses the sheet pile as the retaining wall 1. FIG. Explanatory drawing of the other Example of the obstruction board 26. FIG. Explanatory drawing in case the water flow vertical hole 2 is not built on the line of the retaining wall 1.

Explanation of symbols

1: retaining wall
2: Vertical water passage
3: Water stop plate
4: Square tube
5: Drilling surface
6: Waterway
7: Underground structure

Claims (4)

A water passage vertical hole excavated in the ground,
A water pipe installed inside the water vertical hole, having an outer diameter smaller than the inner diameter of the water vertical hole and opening the water hole,
A water flow material filled between the water flow vertical hole and the water flow tube,
A blocking plate that is inserted into the water pipe and closes a part of the water hole of the water pipe;
A plate installed vertically between a water passage vertical hole and a retaining wall adjacent to the water passage vertical hole, and another part is adjacent to the cross section of the water passage vertical hole. Composed of a water stop plate located in the cross section of the retaining wall,
Structure of water retaining wall.
Drill a water passage vertical hole between the retaining wall and the retaining wall,
Inside the water passage vertical hole, a water pipe having an outer diameter smaller than the inner diameter of the water passage vertical hole and opening the water passage hole is installed,
Filling the water passage between the water passage vertical hole and the water pipe,
Insert a blocking plate inside the water tube to close a part of the water hole of the water tube,
Between the water flow vertical hole and the retaining wall adjacent to the water flow vertical hole, a part is located in the cross section of the water vertical hole and the other part is located in the cross section of the adjacent retaining wall. In addition, install and install a water stop plate in the vertical direction,
Construction method of water retaining wall.
Before the excavation work begins,
Install a retaining wall on the side of the excavation position,
Drill a water passage vertical hole between the retaining wall and the next retaining wall,
Between the water flow vertical hole and the retaining wall adjacent to the water flow vertical hole, a part is located in the cross section of the water vertical hole and the other part is located in the cross section of the adjacent retaining wall. Install a water stop plate on
A water pipe having an outer diameter smaller than the inner diameter of the water passage vertical hole and opening the water passage hole is installed inside the water passage vertical hole,
Fill the water passage between the water passage vertical hole and the water pipe,
Through this water passage material and the water passage hole of the water pipe,
Allow passage of underground water pipes,
During the excavation work,
Insert a blocking plate on the cut-off side inside the water pipe,
Block a part of the water passage hole of the water pipe,
The groundwater collected in the water pipe
Pump it up with a pump and pour water into the ground beyond the excavation site,
At the completion of excavation,
Through the water channel provided inside the excavation part,
The groundwater collected in the water pipe
Injecting water into the ground at a place beyond the excavation place,
Construction method of water retaining wall.
Before the excavation work begins,
Install a retaining wall on the side of the excavation position,
Drill a water passage vertical hole between the retaining wall and the next retaining wall,
Between the water flow vertical hole and the retaining wall adjacent to the water flow vertical hole, a part is located in the cross section of the water vertical hole and the other part is located in the cross section of the adjacent retaining wall. Install a water stop plate on
A water pipe having an outer diameter smaller than the inner diameter of the water passage vertical hole and opening the water passage hole is installed inside the water passage vertical hole,
Fill the water passage between the water passage vertical hole and the water pipe,
Through this water passage material and the water passage hole of the water pipe,
Allow passage of underground water pipes,
During excavation work and when excavation is complete
Insert a blocking plate on the cut-off side inside the water pipe,
Block a part of the water passage hole of the water pipe,
The groundwater collected in the water pipe
Pump up with water and pour water into the ground beyond the excavation site.
Construction method of water retaining wall.

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