JP2001020279A - Water leading apparatus for underground wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable cleansing processing of placed concrete in an initial stage of hardening of the same. SOLUTION: There is provided a water leading apparatus having an expandable water conduit 22, a hydraulic jack 24, and a raw water conveying portion 26. The water conduit 22 is a double pipe consisting of an inner pipe 22a and an outer pipe 22b, and both the edges thereof are opened. The raw water conveying portion 26 has a casing 26a, a filter layer 26b, and an impervious sheet 26c which is hot-water soluble. The casing 26a is of a box shape, and has an open end thereof, which is arranged so as to face an excavated wall surface on the side of natural ground A. The casing is provided with a permeable plate which defines a passage space above the bottom thereof. The filter layer 26b is housed in the easing 26a in a manner being mounted on the permeable plate. Connected to the passage space are ends of three, i.e., first to third feed pipes 26f, 26g, 26h in a manner communicating with the passage space. The three pipes feed cleansing fluid into the passage space, after dissolution of the impervious sheet 26c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water passage device for an underground wall, and more particularly to a water passage device for use in an underground water passage method for allowing groundwater to flow after a watertight underground wall is constructed. Things.

[0002]

2. Description of the Related Art As is well known, when an underground structure, for example, an underground tunnel for a subway or a vehicle-only road is constructed by an open-cutting method, it is possible to prevent collapse of the ground and excavate the inside. Underground walls with water-blocking properties are constructed in order to achieve this.

Various methods are available for constructing this type of underground wall, such as an underground continuous wall method and the like. The underground wall may remain in the ground even after the main body of the underground structure is constructed.

However, if the underground wall having water blocking properties is left in the ground, the groundwater flow will be interrupted, and the groundwater level will rise on the upstream side of the underground wall and on the downstream side, A so-called dam-up phenomenon in which the position is lowered occurs.

Therefore, conventionally, in order to eliminate such a dam-up phenomenon, a water passage device for communicating a groundwater flow is provided at a predetermined location on the underground wall. Such a water passage device includes, for example, a water-permeable filter layer and a biodegradable sheet, and when the underground wall is constructed, the outer periphery of the filter layer is covered with the biodegradable sheet and built. When the biodegradable sheet is decomposed by microorganisms and bacteria in the soil, a structure has been proposed in which a water passage connecting the upper and lower sides of the groundwater flow is formed.

[0006] However, the water passage device having such a structure has the following technical problems.

[0007]

That is, the biodegradable sheet covering the outer periphery of the water-permeable filter layer also has a protective function of preventing the poured concrete from entering the filter layer when the concrete is poured. However, the degradation of the biodegradable sheet is dependent on the activities of bacteria and microorganisms, and it is difficult to control the degradation artificially, making it almost impossible to detect that the biodegradable sheet has completely disappeared. It is possible.

However, in such a state, when fine particles such as muddy water and cement of the cast concrete are wrapped around and adhere to the filter layer, the hardening of the cast concrete, which is considered to have a large effect of removing the fine particles, is considered. Cleaning cannot be performed at an early stage, and the timing of the cleaning process is lost.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an underground water passage device which can effectively perform cleaning. It is in.

[0010]

In order to achieve the above-mentioned object, the present invention provides an underground water blocking wall which is formed so as to block an underground waterway under the ground, and wherein the underground waterway is formed after the underground wall is formed. In a water passage device for an underground wall that forms a water passage that communicates between the water passages, the water passage is a telescopic water pipe installed so as to cross the thickness direction of the underground wall, and A water guiding portion that is communicated with and is pressed against the excavation wall surface when forming the underground wall, wherein the water guiding portion is disposed on the excavation wall surface and has an open end; and a bottom surface of the casing. A water-permeable plate installed inside to separate the passage along, a water-permeable filter layer placed on the water-permeable plate and housed in the casing, and a front side of the filter layer. Provided so as to cover the And water shield sheet of the hot water solubility that, to the passageway and communicating, and a supply pipe for the cleaning fluid is provided on the rear surface of the casing. According to the underground water passage device configured as described above, the water guide portion that forms a part of the water passage that communicates between the underground water passages has an open end on the excavation wall side, and the water passage pipe and the inside. Are connected to each other, a filter layer housed in the casing, and a hot water-soluble water shielding sheet provided to cover the front side of the filter layer. Therefore, until the water-impermeable water-blocking sheet dissolves with warm water, it has water-blocking properties, preventing cast concrete and muddy water from entering the filter layer. It can be artificially controlled by supplying hot water or the like, and the water flowing device of the present invention can be dissolved in the early stage of hardening of the poured concrete. For this reason, when fine particles such as muddy water and cement component of the cast concrete are wrapped around and adhere to the filter layer, at the early stage of hardening of the cast concrete that is considered to have a large removal effect, without losing timing, By injecting a cleaning fluid, for example, water, high-pressure water, compressed air, or a combination thereof into a passage in the casing through the supply pipe, cleaning can be performed effectively. The hot water dissolvable water-blocking sheet is made of a synthetic resin sheet whose dissolution temperature can be selected, and the dissolution temperature can be set in accordance with the temperature rise during the hydration reaction of the cast concrete.
According to this configuration, the hardening of the cast concrete begins,
When the temperature of the muddy water rises due to the hydration reaction of the cement, the temperature rise makes it possible to automatically dissolve the hot water-soluble water shielding sheet set to the temperature at the time of the hydration reaction of the cast concrete. In this case, at the stage where the temperature rises due to the hydration reaction of the cast concrete, the setting concrete has been hardened and its fluidity has almost disappeared. The concrete does not wrap around and enter the filter layer. Further, the dissolving temperature may be set to be equal to or higher than the rising temperature of the cast concrete during the hydration reaction, and hot water heated to the dissolving temperature may be supplied into the casing via the supply pipe. In the case of this configuration, the melting temperature is set to be equal to or higher than the rising temperature of the casting concrete during the hydration reaction. The certainty of dissolution can be increased as compared with the case of dissolution. This warm water also dissolves the impermeable sheet and serves as a cleaning fluid for the filter layer.

[0011]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG.
6 to 6 show an embodiment of the underground wall water passage device according to the present invention.

The water passage device shown in FIG. 1 has a water-blocking ground wall in a ground having a water-permeable sandy soil layer 10 and a non-water-permeable viscous soil layer 12 above and below it. This is an application example in the case of constructing the underground water barrier 14, and the underground waterway (between the sandy soil layers 10 of FIG. 1 located on the left and right of the underground wall 14) is blocked by the construction of the underground water barrier 14.

Therefore, after the underground wall 14 is constructed, a water passage device for forming a water passage 16 for communicating between the underground water passages is used. In the case of the present embodiment, the underground wall 14 is constructed by the underground continuous wall method, the excavation groove 18 is excavated and formed in the ground, and the steel cage 20 is erected.
Is formed.

The water passage device of the present invention has a water passage tube 22 made of a steel tube which can be extended and contracted, a hydraulic jack 24 and a water guide portion 26 as main constituent members. It is erected at a predetermined position in the excavation groove 18 together with the reinforcing cage 20.

In this embodiment, the hydraulic jack 24 is exemplified as the pressing means of the water guide 26. However, the pressing means is not limited to this, and for example, a pneumatic jack or a cylinder may be used. It may be an actuator.

The water pipe 22 and the hydraulic jack 24 are arranged in parallel with the rebar cage 20 so as to be directed substantially horizontally, and coaxially in the depth direction. The water pipe 22 is a double pipe made of a steel inner pipe 22a and an outer pipe 22b, and both ends are open.

The open end of the inner pipe 22 a is located on the ground side A of the excavation groove 18 and is connected to the water guide 26. Details of the water guide 26 are shown in FIGS. The water guide 26 shown in the figure includes a casing 26a and a filter layer 26b.
And a water-shielding sheet 26c that is soluble in hot water.

The casing 26a is a box-shaped one having an open end disposed on the excavation wall side of the ground side A, and has a water-permeable plate 26 separating the passage space 26d above the bottom surface.
e is provided.

As the water-permeable plate 26e, for example, a plate material or a wire net having many holes or slits is used. The filter layer 26b is housed in the casing 26a so as to be placed on the water-permeable plate 26e. For example, the filter layer 26b is formed by randomly winding coil-shaped synthetic resin fibers having a relatively large diameter. A mat (manufactured by Toyobo Co., Ltd., trade name) can be used.

The hot water decomposable water-blocking sheet 26c is to be dissolved by contact with hot water at a predetermined temperature. For example, a synthetic resin sheet whose dissolution temperature can be selected;
Solbron (trade name, manufactured by Nichibi Co., Ltd.) can be used.

In the case of this embodiment, the melting temperature of the impermeable sheet 26c depends on the concrete 21 cast into the excavation groove 18.
Are dissolved in accordance with the temperature rise during the hydration reaction of, for example, those having a dissolution temperature of about 20 ° C.

The impermeable sheet 26c is locked to the casing 26a so as to cover the outer surface of the filter layer 26b housed in the casing 26a.
In this case, the impermeable sheet 26c is
The filter layer 26b may be provided so as to surround the outer periphery of the filter layer 26b stored in the filter layer 26a.

In the passage space 26d, a cleaning fluid (for example,
One end of each of three first to third supply pipes 26f, 26g, and 26h for supplying high-pressure water and / or compressed air) is connected to each other. The first supply pipe 26f arranged on the upper side of the casing 26a supplies high-pressure water or the like.

The second and third supply pipes 26g and 26h are
It is disposed opposite the lower side of the casing 26a,
The supply pipe 26g supplies compressed air, and the third supply pipe 26h
Supplies high pressure water and the like.

The other end of each supply pipe 26f, 26g, 26h is
It extends to the ground side. On the other hand, the outer pipe 2 of the water pipe 22
The open end of 2b is on the excavation side B, and is closed by the end plate 28 so that it can be opened and closed. This end plate 28 is connected to the outer tube 22b.
And a detachable temporary fixing plate 28b bolted to a position outside the flange plate 28a and corresponding to the opening end of the outer tube 22b. It is configured.

The periphery of the open end of the inner pipe 22a on the ground side A is fixed to the casing 26a of the water guide 26 so as to communicate with the inside.

Hydraulic hoses (not shown) are connected to the hydraulic jacks 24, and each hydraulic hose extends to the ground side. Each hydraulic jack 24 has a main body 24a.
And a pair of telescopic plungers 24b and 24c provided on both sides of the main body 24a.

The distal end of the plunger 24b that extends and contracts toward the ground side A of each hydraulic jack 24 is fixed to the back side of the casing 26a. At the tip of the plunger 24c that extends and contracts toward the excavation side B of each hydraulic jack 24, a reaction force plate 34 is fixedly provided.

As shown in FIG. 6, a sheet 30 made of woven cloth or the like having a larger area than the casing 26a is attached to the back side of the casing 26a of the water guide 26.

A through hole having an outer diameter slightly smaller than the outer diameter of the casing 26a is formed substantially in the center of the sheet 30, and the peripheral edge of the through hole is formed by the pressing plate 32 shown in FIG. It is fixed by being fixed to the back side of the casing 26a.

The outer periphery of the sheet 30 is
Is locked to the reinforcing bar cage 20 in a state in which is spread. The sheet 30 fixed in this manner receives the pressure of the concrete 21 when the 21 is driven into the excavation groove 18 and
8. The concrete 21 closely adheres to the uneven surface on the ground A side to prevent the concrete 21 from going around the water passage device.

Next, a method of forming the water passage 16 using the underground water passage device having the above-described configuration will be described. Since the water passage 16 is formed after the construction of the underground water barrier 14, the underwater barrier 14 is first constructed.

The underground wall 14 is constructed by piercing the excavation groove 18 through the sandy soil layer 10, excavating while injecting muddy water below the cohesive soil layer 12 on the lower side, and then reinforcing the steel bar in the excavation groove 18. Basket 2
It is carried out by laying 0 and placing concrete 21 in the excavation groove 18.

At this time, the water pipe 22, the hydraulic jack 24, and the water guide portion 26 are previously locked to predetermined places (places located in the sandy soil layer 10) in the reinforcing rod cage 20. Water pipe 2
2 is filled with a lump of filter material such as crushed stone or gravel to prevent deformation due to water pressure.

When the reinforcing rod cage 20 in which the water pipe 22 and the hydraulic jack 24 are locked is laid at a predetermined position, the hydraulic jack 24 is driven by an operation from the ground before the concrete 21 is cast. .

When the hydraulic jacks 24 are driven, the telescopic plungers 24b and 24c respectively move the ground side A and the excavation side B.
And the plungers 24b and 24c extend,
The hot water decomposable water-blocking sheet 26c covering the surface of the filter layer 26b is pressed against the excavation wall surface on the ground side A, and the reaction force plate 34 is pressed against the excavation wall surface on the excavation side B.

The hydraulic jack 24 may have a structure in which only one side expands and contracts. In this case, for example, the reaction force plate 34 on the excavation side B is set in advance so as to be close to the excavation wall surface. .

When this pressing operation is completed, concrete 21 is poured into the excavation groove 18. This concrete 21
The sheet 30 receives the driving pressure and closely adheres along the unevenness of the digging wall on the digging side B, and the concrete 30
Prevent wraparound of 1.

When the muddy water rises to a predetermined temperature due to the hydration reaction of the cement in the poured concrete 21, the hot water decomposable impermeable sheet 26c dissolves in the early stage of hardening of the poured concrete 21, and the filter The layer 26b is exposed.

In such a state, a plurality of supply pipes 26f, 26 provided on the back side of the casing 26a of the water guide 26 so as to communicate with the internal passage space 26d.
A cleaning fluid selected from high-pressure water, compressed air, a mixed fluid thereof, or the like is fed into the passage space 26d through the g and 26h.

The cleaning fluid sent into the passage space 26d flows along the passage space 26 formed along the bottom surface of the casing 26a, passes through the water permeable plate 26e, and flows out to the filter layer 26b side. The light is emitted to the outside while passing through the filter layer 26b, whereby the filter layer 26b is washed.

In this case, the dissolving temperature of the hot water-soluble water-blocking sheet 26c can be set to be equal to or higher than the rising temperature during the hydration reaction of the cast concrete 21. In the early stage of hardening of the cast concrete 21, hot water heated to the melting temperature is fed into the casing 26a via the supply pipes 26f, 26g, 26h,
By supplying the hot water, the water-blocking sheet 26c can be dissolved.

In the case of this configuration, since the melting temperature is set to be equal to or higher than the rising temperature during the hydration reaction of the cast concrete 21, the temperature during the hydration reaction of the cast concrete 21 slightly varies depending on the time and climate. The certainty of the dissolution can be increased as compared with the case where the dissolution is performed according to the rising temperature.

When the construction of the underground wall 14 is completed as described above, the ground on the excavation side B is excavated, and a structure is constructed inside the underground wall 14. At this time, in this embodiment, after the excavation is performed to the root excavation surface C, the excavation is performed to a deeper depth to expose the end plate 28 closing one end of the water pipe 22.

When the end plate 28 is exposed, the temporary fixing plate 2
8b, remove the bolt, remove it, and connect the outlet pipe 36 to the open end of the water pipe 22 so that the water pipe 1
6 are formed. In addition, for example, in the case where the water-stopping ground wall 14 is provided facing the water-stopping wall 36, the outlet pipe 36 may be provided to connect and connect the water pipes 22 provided on the ground wall 14. However, the outlet pipe 36 is not necessarily required, and it may be sufficient that the opening end of the water pipe 22 is opened in the sandy soil layer 10.

According to the underground water passage device constructed as described above, the water guide portion 26 forming a part of the water passage 16 communicating between the underground water passages is provided at one end disposed on the side of the excavation wall surface. A casing 26a whose side is open and whose inside is connected to the water pipe, a filter layer 26b housed in the casing 26a, and a hot water-soluble water shielding sheet 26c provided so as to cover the front side of the filter layer 26b. And

Therefore, the water impermeable sheet 26c which is soluble in hot water is used.
Has water-blocking properties until it is dissolved by warm water, so that the cast concrete 21 or muddy water is filtered by the filter layer 26b.
The melting time of the impermeable sheet 26c can be artificially controlled by, for example, supplying hot water or setting the melting temperature to the temperature at which the heat of hydration reaction of the cast concrete 21 rises. In the case of this embodiment, it is possible to dissolve the cast concrete 21 at the early stage of hardening.

Therefore, when fine particles such as muddy water or cement of the cast concrete 21 wrap around the filter layer 26b and adhere to the filter layer 26b, the timing of the hardening of the cast concrete 21 which is considered to have a large effect is considered. The washing can be performed effectively without losing water.

[0049]

As described above in detail in the embodiments,
According to the underground wall water passage device according to the present invention, by performing temporal control artificially when exerting the water passage function, the mud film can be formed at any time such as at the initial stage of hardening of the cast concrete. Enables cleaning.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view of an installed state showing an embodiment of an underground water passage device according to the present invention.

FIG. 2 is a perspective view of a main part of FIG.

FIG. 3 is an enlarged perspective view of a water guide shown in FIG. 1;

FIG. 4 is a sectional view of a main part of FIG. 3;

FIG. 5 is a rear view of FIG. 3;

FIG. 6 is a perspective view showing a state where the underground water passage device according to the present invention is locked to a reinforcing bar cage.

[Explanation of symbols]

 14 Underground wall 16 Water passage 18 Drilling groove 22 Water passage 26 Water guide 26a Casing 26b Filter layer 26c Water shielding sheet 26d Passage space 26e Water permeable plate 26f to 26h Supply pipe

Claims (3)

[Claims] An underground water blocking wall is formed so as to block an underground waterway under the ground, and after the formation of the underground wall, a waterway for the underground wall forming a waterway communicating between the underground waterways. In the device, the water passage, a telescopic water pipe installed so as to cross the thickness direction of the underground wall, and communicates with the water pipe,
When the underground wall is formed, a water guide pressed against the excavation wall is provided, and the water guide is disposed on the excavation wall and has an open end, and a bottom surface of the casing is provided. A water-permeable plate installed inside to separate the passage; a water-permeable filter layer placed on the water-permeable plate and housed in the casing; and a front side of the filter layer. An underground wall provided with a hot-water dissolvable sheet that comes into contact with the excavation wall surface, and a supply pipe for a cleaning fluid provided on a back surface of the casing so as to communicate with the passage. Water passing device. 2. The hot water dissolvable water-blocking sheet is made of a synthetic resin sheet whose dissolution temperature can be selected, and the dissolution temperature is set in accordance with the temperature rise during the hydration reaction of the cast concrete. 2. The method according to claim 1, wherein
The underground water passage device as described in the above. 3. The method according to claim 1, wherein the dissolving temperature is set to a temperature equal to or higher than a rising temperature at the time of the hydration reaction of the cast concrete, and hot water heated to the dissolving temperature is supplied into the casing via the supply pipe. The underground wall water passage device according to claim 2, wherein