JP4589084B2 - A retaining wall with a built-in water pipe composed of a plurality of water passages, and a method for ensuring the flow of groundwater using the retaining wall - Google Patents

Description

The present invention relates to a retaining wall with a built-in water pipe formed of a plurality of water passages, and a method for securing the flow of groundwater using the retaining wall before and after ground excavation .

Conventionally, methods for adding a water flow function to a water-impervious earth retaining wall such as an SMW wall include the following methods.
<1> A method of securing a water flow space by inserting a water injection tube into unsolidified soil cement, expanding the tube, and extruding the soil cement.
<2> A method of inserting a split screen with filter material into unsolidified soil cement and pressing the screen against a natural ground with an expansion jack to secure a water passage space.
<3> A method of drilling the soil cement to secure a water passage space after the soil cement wall is hardened.
<4> A special core material with a water flow device with a piston (a member with a steel cover attached to the end of a circular pipe) is built in unsolidified soil cement, and the piston is inserted into the back ground after hardening the soil cement The steel cover at the tip of the piston is melted by electrolytic corrosion to achieve the water flow function.

However, the conventional method for adding a water flow function has the following problems.
<1> It is difficult to completely remove the soil cement in the water flow section, and depending on the extrusion condition of the soil cement, it may not be possible to secure a sufficient input space for the filter material. May be a problem. Furthermore, in large-scale excavation work that requires a long time to construct the retaining wall, it is necessary to take separate measures for the purpose of maintaining the groundwater flow when constructing the retaining wall.
<2> It is difficult to completely remove the soil cement in the water passage portion, and there is a possibility that the deterioration of the water passage function becomes a problem. In addition, since the core material has a special shape, it may be difficult to install the core material depending on the depth and condition of the soil cement.
<3> A water passage construction site is required on the back of the SMW wall. In addition, a heavy construction machine such as an all-round rotary excavator is required for drilling the soil cement, which increases the burden in terms of construction period and construction cost. Furthermore, in large-scale excavation work that requires a long period of time for the construction of the retaining wall, it is necessary to take separate measures for the purpose of maintaining the groundwater flow during the construction of the retaining wall.
<4> The water flow capacity is low in reliability because it depends on the piston insertion situation. Moreover, since the hardened soil cement between the back ground of a piston cannot be removed, there exists a possibility that the fall of a water flow function may become a problem. Furthermore, in large-scale excavation work that requires a long period of time to construct the retaining wall, it is necessary to take separate measures for the purpose of groundwater flow conservation when constructing the retaining wall.

In order to solve the above-described problems, the first invention of the present application is a water retaining wall for controlling water flow between grounds provided between water blocking walls and partitioned by the water blocking walls. A water drainage shaft excavated in the ground, a water pipe composed of a plurality of parallel water passages installed inside the vertical shaft, and a channel filled between the water flow vertical shaft and the water pipe. A water material and a water stop joint provided on a side portion of the water pipe and connected to the water stop wall are configured, and the water pipe is configured by an outer water flow path and an inner water flow path provided adjacent to each other. The outer water passage has an outer opening on the back side of the retaining wall partitioned by a water stop wall, and the inner water passage has a notch that opens on the cut side and a side wall between the adjacent outer water passage. It includes an inner opening that opens to the part, and a stop cock mounting portion positioned between the notch and the inner opening, stop cock of the inner water passage Wearing the stop cock to the wear part, and the inner opening of the inner flow passage, and configured to be able to water blocking between the cutout portion, there is provided a water flow earth retaining walls.

The second invention of the present application relates to a water flow earth retaining wall according to the first invention, by attaching the stop cock to the stop cock mounting portion of the inner flow passage, the cross section of the inner water passage The present invention provides a water retaining wall characterized by blocking.

A third invention of the present application is the water retaining wall according to the first invention, wherein the stop cock is a cylindrical member, and the stop cock is connected to the stop cock mounting portion of the inner passage. It is intended to provide a water passage retaining wall characterized in that the inner water passage is closed by mounting.

The fourth invention of the present application is a method for ensuring the flow of groundwater before and after ground excavation, wherein water blocking walls are respectively installed on both sides of the excavation position, and the first to third inventions between the water blocking walls. The water retaining wall described in any of the above is installed, and before the excavation work begins, the water passage and the outer opening of the outer water passage, the inner opening of the inner water passage, and the notch of the inner water passage ensuring the flow of groundwater, during excavation works, insert a stop cock to the stop cock mounting portion of the inner water conduit, it cuts off a section of the inner passage within the water channel, through the outer opening portion of the outer water passage The groundwater collected in the outer waterway is pumped from the outer waterway and pumped into the ground at a location beyond the excavation site to ensure the flow of groundwater. The water channel is constructed to connect the water pipes in the retaining wall at the opposite position. Te, there is provided a method of ensuring the flow of groundwater.

The well system installed on the retaining wall of the present invention and the construction method thereof can obtain the following effects by means for solving the above-described problems.
<1> Even if a retaining wall is constructed, the construction does not block the flow of groundwater, and a high water flow capacity can be secured.
<2> Water stoppage with a water stopcock can stop the water flow function reliably and easily.
<3> A pump is installed in each water pipe, and different water pressures can be applied to the front ground and the back ground partitioned by the retaining wall.
<4> The solidification material such as soil cement is not injected into the periphery of the well during the construction of the retaining wall, so it is highly reliable against a decrease in water flow capacity caused by clogging.
<5> Water flow capacity can be secured in the entire construction process from the time of construction of the retaining wall to the time of internal excavation and frame construction.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<1> Overall Configuration The structure of the retaining wall of the present invention is configured by providing the water pipe 2 on a part of the retaining wall that is a water shielding portion. The steel sheet pile 23 is connected via the adjacent steel sheet pile 11 to ensure water shielding as a water blocking wall (FIGS. 3 and 4).
The structure of the water flow section will be described below.

<2> Drilling hole The retaining wall is a continuous wall body that is built underground in advance outside the area to be excavated before excavating the ground.
This retaining wall has a water-impervious function that does not allow water to pass through, and it is required that water is not passed to the cut-off side.
This non-water-permeable retaining wall is constructed by various known methods known by names such as sheet piles, for example.
The retaining wall is not only a retaining wall by press-fitting or striking like a sheet pile or a steel pipe sheet pile, but also a structure that continuously forms a column-shaped water-stopping column in the ground known by the name of the SMW method, etc. It can also be used.
A series of retaining walls is constructed for each of a plurality of units by any of the methods, and therefore, a water drain shaft 10 for forming the structure of the present invention is drilled between the units.
Therefore, this water permeable shaft 10 is constructed as a part of the retaining wall on the retaining wall line.

<3> Structure and Installation of Water Pipe 2 As shown in FIG. 1, the water pipe 2 includes an inner water passage 21 and an outer water passage 22 that are parallel to each other, and a steel sheet pile 23 that serves as a fitting joint.
The shapes and areas of the inner water passage 21 and the outer water passage 22 can be arbitrarily set. For example, as shown in FIG. 5, a square pipe or the like may be used for each water passage .
The inner water passage 21 has a notch 211 that opens at a side wall portion that is in contact with the cut-off water passage material 251 that is partitioned by adjacent water blocking walls, and an inner opening portion 212 that opens at a side wall portion between adjacent water passages. And a stopcock mounting portion 213 provided between the notch 211 and the opening 212.
The notch 211 is provided with a screen so that water can pass through. When the stop cock 214 is attached to the stop cock attaching part 213, water passage between the notch part 211 and the inner opening 212 is blocked. To be configured.
The outer water passage 22 is provided with an opening 221 that is opened in a side wall portion that is in contact with the water passage material 252 on the back side of the retaining wall partitioned by the adjacent water blocking wall. A screen is provided in the opening 221 so that water can pass therethrough.
The water pipe 2 is inserted and installed inside the water vertical shaft 10.

<4> Filling with water-permeable material As shown in FIG. 3, the water-permeable materials 251 and 252 are filled into the gap between the water-permeable tube 2 and the water-flow shaft 10.
As this water-permeable material, filter materials used in ordinary wells such as dredged sand can be used.
By filling the water flow material, the groundwater flowing from the back of the water flow shaft 10 enters the water flow shaft 10 and flows out downstream through the water flow material and the water tube.
In this way, even if a water passage is constructed in the ground, the phenomenon of blocking the flow of groundwater does not occur.

<5> Water-flowing state before excavation The water-conducting shaft 10 that maintains water permeability and the non-water-permeable soil-retaining wall are integrated by connecting the water-stopping joint attached to the water-flow pipe 2 and the adjacent retaining wall. It becomes.
Therefore, before excavation of the ground, the flow of groundwater is blocked at the position of the retaining wall, but at the position where the water pipe 2 is installed, the groundwater flows through the inner water passage 21 and the outer water passage 22. It can be secured (FIG. 6).

<6> Water shielding After the excavation work surrounded by the retaining wall starts, the inflow of groundwater to the excavation part must be prevented.
For this purpose, the inner water passage 21 of the water pipe 2 is closed prior to the excavation work.
Specifically, the stop cock 214 is mounted on the stop cock mounting portion 213 provided inside the inner water passage (FIG. 10).
In this embodiment, the stop cock 214 uses a rod-like body insertion method, but other conventional methods such as a sphere embedding method (FIG. 13) may be used.
As shown in FIG. 11, FIG. 12, FIG. 13, and FIG. 14, the water faucet mounting portion 213 is provided with a rubber packing and a rubber water stop plate to ensure water stoppage after the water stop cock 214 is inserted.
During the excavation work, the groundwater level in the excavation is lower than the groundwater level on the back side of the retaining wall, so the water pressure in the inner waterway after installing the stopcock becomes smaller than the water pressure in the outer waterway. As a result, the effect of pushing in the water stop cock is obtained, and the water stoppage is improved. Moreover, the upper side of the water faucet mounting part 213 of the inner water passage 21 has a function as a guide when installing the water faucet 214, the cylindrical water faucet 215, and the steel ball.

<7> Pumping up groundwater As described above, when the stop cock 214 is attached to the inner water passage 21, the groundwater cannot flow to the excavation side and is blocked there (FIG. 15).
Therefore, as shown in FIG. 10, the groundwater collected in the outer water passage 22 is pumped up by the pump 31. Then, water is poured into the ground from the outer water passage 22 at a position beyond the excavation place.
In this way, groundwater flow can be secured even during excavation work.

<8> Pumping up groundwater inside the excavation When the groundwater level inside the excavation is to be lowered while proceeding with the excavation work, a tubular stopcock 215 is attached to the inner water passage 21 (FIG. 16). The cylindrical water stop 215 closes the inner opening 212 of the inner water passage 21 and blocks the inflow of groundwater from the outer water passage 22 (FIG. 17). Then, the pump 32 is installed in the notch 211 of the inner water passage 21 through the inside of the cylindrical water stop 215 from the ground, and the groundwater inside the excavation is pumped up.
In addition, by installing the pumps 31 and 32 in both the inner water passage 21 and the outer water passage 22, different water pressures can be applied to the inside of the excavation partitioned by the retaining wall and other ground.

<9> Construction of water channel When the excavation is completed and the bottom of the excavation is reached, the water channel 6 is provided on the excavation bottom (FIG. 18).
The water channel 6 can be a known one such as a concrete tube.
And if the pumping by the pumps 31 and 32 is stopped, the groundwater accumulated in the water pipe 2 flows through the water channel 6 provided in the open bottom.

<10> Construction of underground structure After 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 cut, the water channel 6 on the lower surface of the structure 7 can be used permanently as a ground water channel.
In addition, the position which installs the water channel 6 is not restricted to the bottom part of the excavation part, If it is the depth below the water level of groundwater, it can be installed anywhere in the excavation part.

The 1st perspective view of a water pipe. The 2nd perspective view of a water pipe. Sectional drawing of a water retaining wall. Sectional drawing of the other Example of a water retaining wall. The perspective view of the other Example of a water pipe. Detailed view of water flow state before the start of excavation work. Sectional drawing of AA 'of FIG. Sectional drawing of BB 'of FIG. Sectional drawing of CC 'of FIG. Detailed view of the water-blocking state inside the excavation. Detail drawing of a stop cock mounting part. The detail drawing of the other Example of a water faucet mounting part. The detail drawing of the other Example of a water faucet mounting part. The detail drawing of the other Example of a water faucet mounting part. Sectional drawing of DD 'of FIG. Detailed view of groundwater pumping work inside the excavation. FIG. 17 is a cross-sectional view taken along line EE ′ of FIG. 16. Detailed view of construction of waterways and underground structures

Explanation of symbols

10. ・ Water shaft 11 ・ ・ Steel sheet pile 12 ・ SMW wall 121 ・ Core material 122 ・ Soil cement 2 ・ ・ ・ Water tube 21 ・ ・ Inner water passage 211 ・ Notch 212 ・ Inner opening 213 ・ Stop Water faucet mounting part 214, stop cock 215, cylindrical stop cock 22, outer water passage 221, outer opening 23, steel sheet pile 251, cut-off side water passage material 252, non-cut-off side water passage material 31, Pump 32 ... Pump 6 ... Water channel 7 ... Underground structure

Claims (4)

A water retaining wall for controlling the flow of water between the grounds provided between the water blocking walls and partitioned by the water blocking walls,
A water drain shaft excavated in the ground,
A water pipe made of a plurality of water paths parallel to each other , installed inside the vertical shaft,
A water flow material filled between the water flow shaft and the water pipe,
Provided on the side of the water pipe, and comprises a water stop joint connected to the water stop wall,
The water pipe is constituted by an outer water passage and an inner water passage provided adjacent to each other,
The outer water passage has an outer opening on the back side of the retaining wall partitioned by a water blocking wall ,
The inner water passage includes a cutout portion opened on the cut-off side, an inner opening portion opened in a side wall portion between the adjacent outer water passage passages, and a stop cock located between the notch portion and the inner opening portion. With a mounting part ,
A water retaining wall that is configured so that a water faucet is attached to the water faucet mounting portion of the inner water passage so that the space between the inner opening and the notch of the inner water passage can be blocked. The structure of a water retaining wall according to claim 1,
By mounting the stop cock on the stop cock mounting portion of the inner water passage ,
It is characterized by closing the cross section of the inner water passage ,
Water retaining wall. The structure of a water retaining wall according to claim 1,
The stop cock is a tubular member;
By mounting the stop cock to the stop cock mounting portion of the inner water passage ,
The inner water passage is blocked,
Water retaining wall. A method to ensure the flow of groundwater before and after ground excavation,
Install water barriers on both sides of the excavation position,
A water retaining wall according to any one of claims 1 to 3 is installed between the water blocking walls,
Before the excavation work begins,
Ensure the flow of groundwater through the water passage and the outer opening of the outer water passage, the inner opening of the inner water passage, and the notch of the inner water passage ,
During the excavation work,
Insert the stop cock to the stop cock mounting portion of the inner water conduit, cut off a section of the inner passage within the water channel,
Groundwater collected in the outer water passage through the outer opening of the outer water passage,
By pumping up from the outside waterway and pumping it into the ground at a place beyond the excavation site, the flow of groundwater is secured.
When excavation is complete,
A method of securing the flow of groundwater by constructing a water channel so that the water pipes in the retaining wall at the opposite position are connected inside the excavated part.

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