JP4262640B2 - Construction method of the impervious wall - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a method for constructing a soil cement underground continuous wall having a water shielding panel, and in particular, a soil cement ground continuous with a wide and thin water shielding panel having a male and female joint together with a casting frame. The present invention relates to a method for constructing a water-impervious ground wall to be submerged in the wall.

Insert a plate-like or sheet-like water-stopping member into the soil-cement continuous wall so that water can be stopped even if cracks occur in the soil-cement continuous wall due to earthquakes or other natural phenomena It was known to do (for example, refer patent document 1).
It has also been known that a synthetic resin sheet is placed in the soil cement underground wall together with the penetrating frame, and the penetrating frame is pulled up to form a soil cement underground continuous wall having a synthetic resin sheet (for example, patents). Reference 2).
It has also been known that a sheet made of synthetic resin is placed together with a penetrating frame after inserting a plate-like or sheet-like water-stopping material into an empty groove or directly in the ground without digging a groove. (For example, refer to Patent Document 3).
On the other hand, it has been known that the joint portion can be in a water-stopped state by making the female joint and the male joint into a shape that can be closely engaged with each other (see, for example, Patent Document 4).
JP-A-5-272132 (FIG. 2, paragraph number 0006) JP 2000-319872 (FIG. 2, paragraph number 0018) Japanese Patent Laying-Open No. 2001-90087 (FIG. 8, paragraph number 0022) Japanese Utility Model Publication No. 7-35860 (FIG. 1)

However, in the above-mentioned Patent Document 1, the water-stopping member used is set in the soil cement wall without using the penetration frame, has high rigidity, and has a narrow width as shown in the drawings. Yes, the joints are closely joined together and have a large number of joints in the continuous wall.
Moreover, in the said patent document 2, although the penetration frame is used, as the water stop member used is shown in the FIG.3 and FIG. It has a narrow width of 1 to 1.5 m and has a shape capable of closely engaging each other's female joint and male joint.
The water-stop member used in Patent Document 3 is the one described in Patent Document 4, that is, a shape capable of closely engaging each other's female joint and male joint. Similar to Document 2, it is narrow and has a shape that allows a female joint and a male joint to be closely engaged with each other.

When the joint interval is short, the processing cost of the joint part is higher than that of the water-stopping member with a long joint interval, and therefore, it is not only an expensive water-stopping material but also a fixed length. In order to obtain a continuous wall shape, if the joint interval is short, a larger number of water-stopping materials are required than a water-stop member having a long joint interval. For this reason, many times of setting work are required to form a continuous wall having a certain length, and labor and time required for construction are required.
In addition, when the joints are shaped so that the female and male joints can be intimately engaged, not only do they need to be positioned accurately when they are joined, but they are also fitted in close contact with each other. Then, in order to set the next water-stopping material, it is impossible to make it self-sink, and it is necessary to adopt a press-fitting penetration method or a penetration method using a high-frequency vibrator.

  In view of such a point, the present invention has a structure in which the female joint and the male joint can be engaged with each other without closely engaging them, and by using a water stop member having a long joint interval, In addition to solving the technical shortcomings, even if such a water-stopping member is used, the soil-cement barrier that does not cause defects in the soil-cement part during insertion of the water-stopping part while ensuring water-stopping of the joint part. The object is to provide a method for constructing an underwater wall.

The method for constructing the soil cement water-impervious underground wall of the present invention is a method of constructing a soil cement underground continuous wall, and then, while the soil cement is uncured and has fluidity, has a wide and thin joint having male and female joints. A method of constructing a water-impervious underground wall in which a soil-cement wall exists on both sides of the water-impervious panel in a continuous underground wall by inserting the water-impervious panel into a soil cement together with a casting frame. The installation frame is narrower than the portion excluding the joint portion of the water-impervious panel and is made of thick steel, and is provided with means for supporting the water-impervious panel below the water-impervious panel. And a grouting channel on the opposite side of the surface for supporting the water shielding panel of the placing frame, and the water shielding panel has a width of 1.8-2. 5m of the wide is a thin-walled steel panel, the female joint on one side, A male joint on the side, the lower end of the female joint is sealed, and the female joint and the male joint can be engaged with each other without closely engaging, The side opening (slit part) provided on the side surface of the female joint is sealed with a material having a strength that can be broken by insertion from above the male joint before being inserted into the soil cement, and the water shielding panel is While self-sinking in the soil cement in the state where it is mounted on the casting frame, or after self-sinking , the female joint is filled with a filler, and the next water-impervious panel having a male joint engaged with the female joint is driven. The process of filling the filling into the female joint of the next water-impervious panel while self-sinking in the soil cement while it is attached to the installation frame, or after self-sinking , is followed by the installation frame Grouting from the grout injection channel A method for constructing a water shield underground wall, characterized in that pulling on the ground while.

According to this construction method, the lower end portion of the water shielding panel is held by the supporting means of the placing frame, and the upper end of the water shielding panel is held by the holding and releasing means above the placing frame. In addition, while the soil cement is uncured and has fluidity, it is also possible to sink (i.e., self-sink) into the soil cement together with the casting frame.
In particular , ruler receiving members are installed on both sides of the soil cement wall, and this ruler receiving member has a roller at the tip of the member protruding in the direction of the thickness center of the soil cement wall and moves along the ruler receiving member. An insertion ruler member that can be fixed at an arbitrary position and has a water shielding panel attached thereto is placed, and the placement frame is hung by a suspension hook at the upper end, and the position is regulated by the roller of the insertion ruler member. If the construction method of the impermeable ground wall that self-sinks with its own weight in the soil cement at the predetermined position is adopted, even when the installation frame with the water-impervious panel is self-sunk into the soil cement, it is accurately placed in the predetermined position. This is a preferable construction method.
In addition, although the side opening part (slit part) in the female joint of a water-impervious panel is inserted in soil cement, the material which seals with the material of the intensity | strength broken by insertion from the upper direction of a male joint is not specifically limited. Examples thereof include a cloth material or a synthetic resin tape material having an adhesive material applied to the back surface.

  In addition, when using woven fabric as a material that seals the side opening (slit part) in the female joint of the water-impervious panel, if the warp or weft is arranged along the slit direction, the male joint can be cut. It becomes easy. Of course, since the water-impervious panel is attached to the placement frame and is submerged, even when the water-impervious panel is self-sunk while attached to the placement frame, the above-mentioned sealing material is from above the male joint. It is broken by insertion. Needless to say, it is natural that the pressure of the soil cement at the time of insertion into the soil cement has a strength that does not break or peel off.

  The filler to be filled in the female joint may be any material that can be inserted into the male joint. For example, cement milk and mortar, and those in which a curing retarder is mixed with these, asphalt, polymer Examples include highly viscous materials such as soil mixed with bentonite. Among them, non-hardening fillers such as soil mixed with bentonite can follow the deformation of the water-impervious panel at the joint during an earthquake, etc. It is a material. However, it is necessary that asphalt, polymer, and the like have fluidity when filled into the female joint.

The filler filled in the female joint may be a filler having the same liquid specific gravity as that of the soil cement, but it is more than the liquid specific gravity of the soil cement in order to reduce the risk of the liquid specific gravity being lowered due to a mixing error. It is further preferred to use the fillers made. The sealing material that sealed the slit of the female joint is broken by the insertion of the male joint in the next water shielding panel, but by changing the liquid specific gravity in this way, the soil cement on the soil cement wall becomes female. Mixing in the joint (that is, mixing in the female joint due to the hydraulic pressure difference between the filler and the soil cement) can be prevented, and the first filler filled in the joint remains in the state where the soil cement is cured. Can do.

Further, the timing of filling the filler into the female joint may be filled while being self- sunk in the soil cement in a state of being mounted on the casting frame, or may be performed after the self-sinking in the soil cement is completed. . When the latter is carried out after self-sinking into the soil cement, since the upper end of the female joint for injecting the filler is close to the ground, it is easy to inject the filler. It is.

In addition, when the depth of the soil cement underground continuous wall to be built is large, naturally the length of the water shielding panel etc. to be used is also large, but when submerging deeply in the state where the filler is not filled The pressure difference between both sides of the portion sealing the side opening of the female joint becomes large, and it cannot be said that there is no possibility that a part of the sealing material is peeled off or damaged. When such a risk is expected, it is preferable that the soil cement is filled while being self- sunk in a state of being mounted on the casting frame. In this case, by injecting the filler after being set to some extent, the upper end of the female joint is at a position higher than the ground, but can be injected at a lower position. Even in such a case, it is preferable that the uppermost end position of the filled filler and the upper end surface position of the soil cement are substantially the same position to reduce the pressure difference between them.

  In addition, as the grout that is injected when the casting frame is lifted to the ground, a graut material such as soil cement liquid mixed with cement milk or soil is used, and the strength is the same as when the constructed soil cement is solidified. Most preferred is a grouting material. An example of this is cement milk having a low water cement ratio, such as cement milk having a water cement ratio of 80%.

Moreover, it is preferable that the grout injection path at this time is not deformed when pulled up or inserted as a steel cylinder. Deformation may make it difficult to inject grout material. In order to further facilitate the injection of the grout, it is particularly preferable to insert a hose into the tubular state and pump the grout using a grout pump.
And the time to raise the placement frame to the ground while injecting grout from the grout injection path is the time when the water shielding panel left in the soil cement does not move even if the placement frame is raised. Most preferably, for example, after the time when the soil cement loses fluidity, it is performed when the casting frame can be pulled up. In order to facilitate this pulling up, it is preferable that the casting frame is coated with a release material (or release agent).

A particularly preferable placement frame has a rib on the opposite side of the surface that supports the water-impervious panel, a hook is provided on the rib, and a grout injection path is provided along the rib. .
The hook provided on the rib of the placing frame is used to suspend the placing frame from above. Therefore, it is particularly preferable that a means for holding and opening the water shielding panel is provided at a position lower than the upper end of the placing frame.
Moreover, in order to hold | maintain a water-impervious panel in the part except a male and female joint part, the frame for placement is made narrower than the part except the joint part of a water-impervious panel.

In addition, although the water-impervious panel to be used has a male and female joint part, the panel width is wide and a thin water-impervious panel, and even a steel panel itself has low rigidity, for example, The panel has a width of 1.8 to 2.5 m and a thickness of 5 to 9 mm. Although length is not specifically limited, For example, it is about 5-40 m.
Moreover, the casting frame to be used is narrower than the portion excluding the joint portion of the water-impervious panel, is made of thick steel, and has high rigidity. It is made of steel with a width of 35 mm and exceeding 1.5 m to about 2.3 m.

Further, as the water-impervious panel used in the method for constructing the inner wall of the impermeable ground of the present invention, the female joint is a tubular joint (particularly preferably cylindrical), and the male joint is T-shaped. This is a T-shaped joint of the mold.
Note that the male joint has a tight connection between the female joint and the male joint, even though the upper stick part in the T-shape is curved and the upper stick part in the T-shape is replaced by a circular or oval cross section. Any structure that can be engaged with each other without being engaged with each other can be used. However, it is most preferable that the male joint is T-shaped in terms of easiness of setting in the female joint filled with the filler.

  Furthermore, in the present invention, the method for constructing the soil cement wall as the underground continuous wall may be any construction method, but in order to construct the soil cement in the ground with the uniform wall thickness and the upper and lower parts. While circulating an endless chain with a drilling blade around the cutter post, the cutter post is traversed while being inserted into the ground, and at the same time, the cement-based solidified material is discharged from the lower end of the cutter post or near the ground surface. Particular preference is given to the method of using the device.

In the construction method of the inner wall of the impermeable ground according to the present invention, the placing frame equipped with the impermeable panel is a construction for lifting and self-sinking in the soil cement by its own weight. Is no longer necessary.
In addition, according to the construction method of the water-impervious ground wall according to the present invention, the female joint and the male joint have a joint that can be engaged with each other without closely engaging, and the joint joint has a long width. A thin water-impervious panel is used and the joint is filled with a filler.
In a place where the upper layer is soft ground and the lower layer is hard ground, if an underground wall is constructed across both grounds, a large deformation occurs at the boundary surface of the upper ground during an earthquake, and the soil cement part There is a risk of cracking, etc., but because the long, wide and thin water-impervious panel is used, the number of joints is small, and the joints are in a state filled with filler, Leakage from the joint can also be prevented, and it is useful as a method for constructing an impermeable ground wall in places where leakage of contaminated groundwater is not allowed, such as a contaminated soil prevention wall or a waste disposal site.

Further, according to the present invention, the placing frame equipped with the water-impervious panel is placed in the soil cement at a predetermined position while being guided by being regulated by the roller of the insertion ruler member while being hung by the suspension hook at the upper end. Since self-sedimentation is caused by its own weight, it is possible to accurately deposit in the soil cement at a predetermined position even in the self-settlement work.

  Furthermore, in the present invention, since a water shielding panel having a long joint interval is used, the processing cost is higher than that of a member part excluding the joint when a continuous wall shape having a fixed length is used compared to a panel having a short joint interval. The ratio of joints to be reduced can be reduced, and the total number of panels used when forming a continuous wall with a fixed length is reduced. Therefore, not only the material cost is reduced, but also a fixed length. Because it has a continuous wall shape, less settling work is required, and the labor and time required for construction can be reduced.

Further, according to the present invention, the female joint and the male joint are structured so as to be able to engage with each other without closely engaging, and when the water shielding panel is driven in a straight line, the opening space of the female joint is used. A gap is created between the male joint and the male joint, and when the next impermeable panel is inserted into the already imbedded impermeable panel, the two joints in the joint are smoothly engaged and the next The water panel can be sunk .

Even in such a structure, the female joint has a structure in which the lowermost end is sealed, and the side opening (slit part) in the female joint is broken by insertion from above the male joint before being inserted into the soil cement. After sealing with a strong material and self-sinking the water shielding panel, when filling the filler into the female joint, it is possible to prevent leakage of the filler from the opening (slit part) etc. The slit sealing material is engaged while being cut by the male joint of the water-impervious panel inserted from above, and the joint portion can be filled with the filler. Therefore, even if a gap is generated between the opening space of the female joint and the male joint, water leakage from the joint portion can be prevented.

Note that, as described above, the female joint has a structure in which the lowermost end is sealed, and the side opening of the female joint has a strength to be broken by insertion from above the male joint before being inserted into the soil cement wall. Since it is sealed with a material, the soil cement does not enter the female joint even if it is set in the soil cement wall. Conversely, if the female joint is structured such that the lowermost end is not sealed, or the side opening at the female joint is left as it is, the soil cement enters the female joint when it is set in the soil cement wall. Once it has entered, it is difficult to completely remove the soil cement, and a lot of soil cement remains in the female joint even after the removal operation. Thus, in the state where the soil cement remains, the filling degree of the filler to be filled in the female joint later becomes insufficient. As in the present invention, when the side opening in the female joint of the water shielding panel is sealed with a material having a strength that is broken by insertion from above the male joint before being inserted into the soil cement wall, As in the process, it is possible to adopt a process in which the water shielding panel is set in the casting frame and is submerged in the soil cement wall to fill the female joint with a filler.
When a filler with a liquid cement specific gravity or higher is used as the filler to be filled in the female joint, the female joint slit (opening) is sealed by inserting the male joint in the next water-blocking panel. The sealing material that had been cut will be broken, but by changing the liquid specific gravity in this way, the soil cement of the soil cement wall will be mixed into the female joint (that is, the female joint is caused by the hydraulic pressure difference between the filler and the soil cement). In the state where the soil cement is hardened, the filler filled first in the joint can be left.

Further, the water-impervious panel used in the present invention is a wide-thin steel panel having a width of 1.8 to 2.5 m , and itself has low rigidity and is easily bent. Because the impermeable panel is wide, the casting frame must be wider and thicker than the narrow impermeable panel, and the casting frame can If it is pulled up to, the water-impervious panel may be deformed in the width direction.Therefore, it is necessary to hold the next water-impervious panel on the casting frame and sink it while holding the water-impervious panel on the casting frame. is there. Thus, it is necessary for the casting frame to have high rigidity, and for this reason, the volume occupied by the casting frame in the soil cement has to be large. If such a large-sized casting frame is simply pulled up, there is a risk of cracks occurring in the soil cement part as the soil cement tries to move to the place where the casting frame previously existed. However, according to the present invention, the casting frame is lifted to the ground while injecting the grout from the grout injection path, so that the soil cement does not crack and the soil cement portion does not have a defect. It can be a cement underground continuous wall.

  As described above, according to the present invention, the female joint and the male joint have a structure that can be engaged with each other without closely engaging them, and the use of the water shielding panel having a long joint interval results in the disadvantages of the prior art. In addition, it is possible to construct a soil cement underground continuous wall that does not cause defects in the soil cement portion during work while ensuring water-stopping of the joint portion.

  Note that, when simply pulling up the casting frame having a large volume, a force (that is, negative pressure) that does not cause a hollow portion to be generated below the casting frame is generated, making it difficult to pull up the casting frame. In some cases, the water-impervious panel may float upward or move laterally. However, even if the casting frame has a large volume, these adverse phenomena can be prevented from occurring by pulling the casting frame up to the ground while injecting the grout from the grout injection path.

The water shielding panel used for carrying out the present invention will be described with reference to the example shown in FIG. FIG. 1 is a perspective view showing an example of a water shielding panel used in the present invention.
1 has a rectangular shape, one side having a male joint 2 and the other side having a female joint 3 provided with a slit (opening) 4 in the vertical direction of the side surface. Direction). The impermeable panel 1 of this example has a thickness t ₁ 6 mm, a width 2.12 m, and a length 8 m as shown in FIG. 2, and the male joint 2 has a thickness t ₂ 6 mm and a width h as shown in FIG. ₂ 65 mm T-shaped joint, female joint 3 is cylindrical (thickness t ₃ 6 mm), inner diameter (diameter of gap) h ₃ is 102.3 mm, and slit (opening) has an opening width of 30 mm 4 is a tubular joint having a side surface in the vertical direction. The lower end of the female joint 3 is sealed at the lower end as shown in FIG. In this figure, the blocking portion 3a has a slope shape, but it may be a horizontal blocking portion. When the lower end of the female joint 3 is sealed in a slope shape, the lower end portion of the male joint 2 is set to a length where the slit 4 of the female joint 3 exists as shown in FIG.

The slit 4 is sealed with a resin tape 5 as shown in FIG. 2, for example, before the water shielding panel 1 is self- precipitated into the soil cement wall. The sealing time may be before it is set in the soil cement wall, but is most preferably performed when the water-impervious panel 1 is placed horizontally on the storage site. Furthermore, as shown in FIG. 2, it is preferable that the upper part of the slit 4 of the female joint 3 is wide and this V-shaped portion is used as an insertion guide 4a for the male joint. In FIG. 2, in order to clearly show the slit 4, the resin tape 5 is shown in a separated state where the slit is not sealed, but the slit 4 is sealed with the resin tape 5 as shown in FIG. 3.
Moreover, as shown in FIG. 1, many reverse U-shaped hooks 6 are attached to the lower end part of the water-impervious panel 1, and the front-end | tip part is in the closed state. In order to attach the hook 6 to the water shielding panel 1, the reinforcing plate 7 is welded to the lower end portion of the water shielding panel 1, and the hook 6 is attached to the reinforcing plate 7. This hook 6 is for hooking on a water shielding panel supporting means at the lower end of the placing frame 11 described later.
As shown in FIG. 1, metal fittings 8 having horizontal holes protrude from the left and right upper end portions of the water shielding panel 1. This hardware 8 is also attached on a reinforcing plate 9 welded to the water-impervious panel 1.

FIG. 3 shows an example of a placement frame 11 used when the water shielding panel 1 is set in the soil cement wall. The casting frame 11 shown in FIG. 3 has a width of 1.9 m and is narrower than the width of 2.06 m excluding the joint portions 2 and 3 of the water shielding panel 1. However, the length is 9 m, and the length of the portion where the impermeable panel 1 is not present is 1 m above when the impermeable panel 1 having a length of 8 m is mounted. In this example, the wall thickness of the placing frame 11 is 28 mm.
A metal fitting 13 having a hole through which the bolt 14 can be inserted exists at the upper end of the placing frame 11. The metal fitting 13 is a metal fitting for holding the upper side of the water-impervious panel 1, and the metal fitting 8 above the water-impervious panel 1 is disposed above the water-impervious panel 1 via a turnbuckle 15 as shown in FIG. 3. Is held. That is, as shown in FIG. 4, the bolt 14 is inserted into the hole at the upper end of the turnbuckle 15 and the hole of the metal fitting 13 of the placing panel 11 and the nut is tightened to fix the lower end of the turnbuckle 15. Bolts 14 are inserted into holes formed in the U-shaped branching portion which is the side portion and the metal fitting 8 above the water shielding panel 1 and fixed by tightening nuts.
As described above, since the water-impervious panel 1 has the hook 6 at the lower end hooked on the pin 12 of the placing frame 11, by tightening the turnbuckle 15, the water-impervious panel 1 is pulled upward, As shown in FIG. 5, it is possible to mount the water-impervious panel 1 along with the placement panel 11.

  Further, as shown in FIG. 6, a reinforcing rib 16 is provided on the back surface of the placing frame 11 where the water shielding panel 1 is not mounted, and the placing frame 11 is suspended on the uppermost portion of the reinforcing rib 16. A hanging hook 17 for lowering is attached. Furthermore, a rectangular cylindrical passage 18 that passes vertically along the reinforcing rib 16 is provided, and a grout hose 19 is inserted into the passage 18 so that the grout can be discharged from the lower end of the passage 18. Yes.

The suspension hooks 20 shown in the upper two places and the lower two places of the placement frame 11 shown in FIG. 3 are detachably screwed into screw holes 21 provided in the placement frame. When mounting the water shielding panel 1 as shown in FIG. 3, the hanging hook 20 attached to the surface on which the water shielding panel 1 is mounted is removed.
When the casting frame 11 is moved to or from the storage place before the waterproof panel 1 is mounted or after the installation of the waterproof panel 1 is completed, the casting frame is used. The suspension hook 20 is attached to 11 and the placing frame 11 is suspended and moved in a horizontal state.
The casting frame 11 is set together with the water shielding panel 1 in the soil cement wall, and is later collected on the ground by leaving the water shielding panel 1 in the soil cement wall. 11, it is desirable to apply a release material (or release agent) in advance in a state where the water shielding panel 1 is not held.

Next, an example of an apparatus for constructing an underground continuous wall of soil cement according to the present invention is shown in FIG. Fig.7 (a) shows the apparatus of the state which is building the soil cement, FIG.7 (b) shows the principal part enlarged view of an apparatus.
The device 22 for constructing the soil cement underground wall has a structure in which an endless chain 24 having an excavating blade 23 can be rotated around a cutter post 27 by a drive roller 25 and an idle roller 26. The cutter post 27 can move up and down along the mast 28. The cutter post 27 can move laterally as the mast 28 moves laterally. The mast 28 can be laterally moved with respect to the frame 30 of the base machine by a hydraulic cylinder 29 and can also be laterally moved by a crawler 31 of the base machine. Further, as shown in FIG. 7 (b) , the device 22 has a discharge port 32 for the cement-based solidifying material liquid at the lower end, and rotates the endless chain 24 while discharging the cement-based solidifying material liquid. While the cutter post 27 is traversed, the excavated soil and the cement-based solidifying material liquid are stirred and mixed to form a soil cement while excavating the ground. In this way, a soil cement underground continuous wall can be constructed. If the width that can be excavated by the excavating blade 23 is, for example, 550 mm, a soil cement underground continuous wall having a uniform width of 550 mm can be constructed. The depth of the soil cement underground continuous wall is the length of the cutter post 27. The soil cement underground continuous wall having a desired depth can be constructed by making it possible to cope with the depth of construction.
In this example, a soil cement impermeable ground wall with a width of 550 mm was constructed up to a depth of 20 m reaching the impermeable layer of the ground.
In addition, the water-impervious panel described above is planned to be laid down to a depth of 8 m at the upper end. The reason for having a water-impervious panel only at the top 8m is that the ground boundary where large deformation can occur at the top and bottom of the earthquake is only in the shallower part of the top 8m, and deeper than 8m. This is because the ground had no boundary layer. Thus, the ground constructed in this example is a ground where there is no possibility of cracking during an earthquake even if there is no water shielding panel in a portion exceeding 8 m, and water shielding can be ensured only with soil cement.

After the soil cement underground wall is constructed in this way, when the soil cement is uncured and has fluidity, the water shielding panel 1 is attached to the placing frame 11 as described above and into the soil cement. Insert it.
It is preferable to use an insertion ruler member 33 as shown in FIG. 8 so that the water shielding panel 1 is positioned at the center of the width of the soil cement during the insertion.
As shown in FIG. 8, ruler receiving members 34 made of H-shaped steel are installed on both sides along the soil cement wall, and the insertion ruler member 33 is movable along the ruler receiving member 34 and fixed at an arbitrary position. It is possible to have a structure in which a roller 36 is provided at the tip of a member 35 projecting in the direction of the soil cement wall. The width between the rollers 36 in the pair of insertion ruler members 33 having such a structure is such that the water shielding frame 1 can pass along with the placing frame 11, and the water shielding panel 1 has a width of the soil cement wall. It has been adjusted to be located in the center of the. FIG. 8A shows a set state, and FIG. 8B shows a construction state in which the water shielding panel is inserted into the soil cement wall together with the placing frame.

Using such an insertion ruler member 33, the placement frame 11 on which the water shielding panel 1 is mounted is set in the soil cement by its own weight while being suspended by the suspension hook 17 at the uppermost end. Thus, self-sink is possible in the present invention. In addition, in the single settling, even the thin and wide water-impervious panel 1 that is easily deformed by bending shear during the settling work can be set without being deformed by using the placing frame 11. In ordinary soil cement, after the soil cement wall of the portion is constructed, it can usually settle for about 2 to 3 hours.
In this example, as shown in FIG. 9, the grouting material kneaded by the grouting mixer 37 and pumped by the grouting pump 38 enters the female joint 3 of the water shielding panel 1 through the grouting hose 19 in the state where the installation is completed. Filled.
As shown in FIG. 9, even if the water shielding panel 1 enters the soil cement underground wall, the upper portion of the placement frame 11 protrudes above the ground. However, since the worker can stand on this side of the soil cement underground wall, that is, on this side where the placement frame 11 does not exist, the worker can use the grout hose from the grout pump and the placement frame. The grout hose can be connected on the ground surface.

The grout material to be used can prevent the soil cement wall soil cement from being mixed into the female joint 3, such as one whose density is equal to or higher than the density of the soil cement wall soil cement. Preferably, for example, a clay-based material such as bentonite in a ratio of 3 to 5 by weight with respect to the cement amount, a small amount of sand and cement (further added with an admixture for making fly ash or fluidity). What knead | mixed with water so that sand etc. may not isolate | separate at the time of pump injection | pouring is used. Further, a curing retarder may be kneaded to delay the grout curing so that the time during which the next water shielding panel 1 can be inserted is lengthened.
Moreover, you may use the bentonite mixed soil which knead | mixed soil and bentonite with water instead of said grout material as a filler. In this case, since the bentonite mixed soil does not solidify, the installed water-impervious panel 1 is allowed to be slightly deformed at the joint during an earthquake, and the filler is not damaged even if deformed at the joint. Water performance can be maintained.

After filling the female joint 3 with the filler in this way, the water-impervious panel 1 to be connected next is self- sunk in the soil cement together with the placing frame 11.
In this case, as shown in FIG. 10, the T-shaped male joint 2 in the next water shielding panel 1 is inserted into the female joint 3 of the water shielding panel 1 filled with the filler of the water shielding panel 1. Sedimentation . In FIG. 10, the central water-impervious panel 1 is the water-impervious panel inserted next.
11A, 11B, and 11C are enlarged plan explanatory views showing the female joint 3 in the construction process.
In Fig.11 (a), the female joint 3 of the water shielding panel 1 filled with the filler of the inserted water shielding panel 1 and the male joint 2 of the water shielding panel 1 inserted next are shown with a broken line. Yes.
The sealing material (in this example, the resin tape 5) that has sealed the slit 4 of the female joint 3 is broken by the insertion of the male joint in the next water-impervious panel 1, as shown in FIG. 11 (b). In this way, the filler filled in the female joint 3 is made to have a liquid specific gravity higher than that of the soil cement of the soil cement wall, so that the soil cement of the soil cement wall is mixed into the female joint 3 (that is, the filler and the soil). 11), the state of the joint portions 2 and 3 when the soil cement is hardened is first shown in the joint 3 as shown in FIG. The filler filled in can be left.
The steps of sinking the water shielding panels 1 to be connected one after another into the soil cement continuous wall thus constructed in the soil cement together with the casting frame 11 and the injection of the grout material into the female joint 3 are carried out. repeat.

Thereafter, the setting of the soil cement progresses, and even if the casting frame 11 is pulled up, the water shielding panel 1 left in the soil cement does not move in the thickness direction (usually after the construction of the soil cement 3 When this time is exceeded and this state is reached in about 4 hours), as shown in FIG. 12, the placing frame 11 is sequentially pulled up to the ground while injecting grout from the grout injection path 18. That is, the grout material kneaded by the grout mixer 37 and pumped by the grout pump 38 passes through the grout hose 19 existing in the passage 18 of the placement frame 11 and the volume of the placement frame 11 pulled up. The grout material is discharged from the lower tip of the placing frame 11.
In this example, cement milk that is easy to procure as a grout material is used. The cement milk preferably has a strength after solidification that is equal to or higher than the strength of the soil cement after solidification.
By pulling up all the placing frames 11 in this way, as shown in FIG. 13, the wide and thin water-impervious panels 1 connected to each other in the state where the filler is present in the joint portion are widened. Soil cement underground continuous wall can be constructed in the center of the direction.

In addition, when construction interruption time is short, such as a lunch break, a filler is put in the female joint 3 of the water-shielding panel 1 attached to the placement frame 11 without pulling up the placement frame 11 immediately before that. It is left in the soil cement in the inserted state, and after the next water-impervious panel 1 is self- sunk together with the casting frame 11 at the time of restarting, the grout material is discharged from the tip of the casting frame 11 set before interruption. It is also possible to raise it.
FIG. 14 shows a state in which the placing frame 11 is pulled up by a crane. Although not clearly shown in FIG. 14, even in this case, as shown in FIG. 12, the grout material is pulled up and discharged from the lower end of the placing frame 11.
Furthermore, if it becomes difficult to pull up the placement frame 11 that was laid before the interruption after resuming the construction because the next process will be the next day, all the placement frames 11 are raised before the interruption. . Of course, at this time, the placement frame 11 is pulled up while discharging the grout material from the tip.

Thus, when the next process is interrupted, as shown in FIG. 14, after constructing the underground continuous wall for the day of soil cement, the cement is removed from the apparatus 22 shown in FIGS. 7 (a) and 7 (b). The retreat excavation is performed by circulating the endless chain 24 while discharging the bentonite mud added with water instead of the system solidifying material liquid. By placing the device 22 in the retreat excavation in which bentonite and excavated soil that do not solidify are mixed, it becomes possible to construct a soil cement underground continuous wall the next day. In addition, it is preferable that the placing frame 11 sunk immediately before the retreat excavation is left in the soil cement together with the water shielding panel 1, and the last placement frame 11 is pulled up when the retreat excavation has progressed.
Thus, even if all the placement frames 11 are pulled up, solidification of the soil cement proceeds until the construction is resumed after the next day, and the water shielding panel 1 is not deformed when the construction is resumed after the next day.
Therefore, the device 22 was made to traverse the previously constructed soil cement underground continuous wall while circulating the endless chain 24 while discharging the cement-based solidifying material liquid, thereby continuing to the previous soil cement underground continuous wall. The soil cement is made into soil cement, and then the device 22 is made to traverse while circulating the endless chain 24 while discharging the cement-based solidifying material liquid in the opposite direction. The inner wall is constructed, and the water-impervious panel 1 is self- sunk using the placing frame 11 by the process described above.

As described above, according to the method of the present invention, that is, after the soil cement underground wall is constructed, while the soil cement is uncured and has fluidity, the male and female joint portions are wide and thin. A water impervious panel is inserted into a soil cement together with a casting frame, and a water impervious underground wall having soil cement walls on both sides of the water impervious panel in the underground continuous wall is constructed. The installation frame is narrower than the portion excluding the joint portion of the water-impervious panel and is made of thick steel, and is provided with means for supporting the water-impervious panel below the water-impervious panel. And a grouting channel on the opposite side of the surface for supporting the water shielding panel of the placing frame, and the water shielding panel has a width of 1.8-2. a wide thin-walled steel panel of 5m, female joints to one side The other end has a male joint, the female joint is sealed at the lowermost end, and the female joint and the male joint can be engaged with each other without being closely engaged. The side opening in the female joint of the water panel is sealed with a material that can be broken by the insertion from above the male joint before being inserted into the soil cement, and the water blocking panel is attached to the casting frame. In this state, it is allowed to self-sink in the soil cement, the female joint is filled with a filler, and a water-impervious panel having a male joint on the female joint side is attached to the casting frame to be self- sunk in the soil cement. A water-impervious area having a water-impervious panel by repeating the process of filling the female joint inserted later with filling material, and then pulling the casting frame up to the ground while injecting grout from the grout injection path. Build the inner wall Rukoto can.

It is a perspective view which shows an example of the water shielding panel used for this invention. It is a principal part expansion perspective view of the water-impervious panel shown in FIG. It is a perspective view which shows the water shielding panel used for this invention, and the frame for placement. It is a principal part expansion perspective view which shows the upper part fixed state of a water-impervious panel and the placing frame. It is the front view which looked at the state which attached the impermeable panel to the frame for placement from the impermeable panel side. It is the perspective view which looked at the state which attached the water-impervious panel to the placing frame from the placing frame side. It is the front view (a) and principal part enlarged view (b) which show an example of the apparatus which builds a soil cement continuous wall. It is the top view (a) which shows an example of the insertion ruler member for positioning a water-impervious panel in the width direction center part of a soil cement continuous wall (underground wall), and the top view (b) in construction. It is front explanatory drawing which shows the process of filling a filler in the female joint of the water-impervious panel sunk in the soil cement continuous wall. It is a top view which shows the state which the water shielding panel was inserted in the soil cement continuous wall with the frame for placement. It is expansion plane explanatory drawing which shows a female joint part according to construction process (a) (b) (c). It is front explanatory drawing which shows the process of pulling up the casting frame from the soil cement continuous wall. It is a top view of the continuous underground wall containing the completed water-impervious panel. It is front explanatory drawing which shows the process of pulling up the placing frame in the state which has put the apparatus which builds a continuous underground wall in the retreat excavation part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Water-impervious panel 2 Male joint 3 Female joint 3a Sealed part of female joint lower end 4 Side opening of female joint (slit)
4a Insertion guide 5 Resin tape 6 Hooks 7 and 9 Reinforcement plate 8 Metal fitting 11 Placing frame 12 Pin 13 Metal fitting 15 Turn buckle 16 Reinforcement rib 17 Hanging hook 18 Passage (grouting channel)
19 Grout hose 22 Soil cement underground building device 23 Drilling blade 24 Endless chain 27 Cutter post 32 Discharge port 33 Insertion ruler member 36 Roller

Claims (4)

After construction of the soil cement underground wall, while the soil cement is uncured and fluid, insert a wide and thin water-impervious panel with male and female joints into the soil cement along with the casting frame. A method for constructing a water-impervious underground wall in which soil cement walls exist on both sides of the water-impervious panel in the underground continuous wall,
The casting frame is narrower than the portion excluding the joint portion of the water-impervious panel and is made of thick steel, and is provided with means for supporting the water-impervious panel below, and the water shield above it. A means for holding and releasing the panel is provided, and a grout injection path is provided on the opposite side of the surface for supporting the water shielding panel of the placing frame.
The water-impervious panel is a wide thin steel panel having a width of 1.8 to 2.5 m , having a female joint on one side and a male joint on the other, the female joint being sealed at the lowermost end, and female The joint and the male joint are of a structure that can engage with each other without closely engaging,
Before the side opening provided on the side surface of the female joint of the water shielding panel is inserted into the soil cement, it is sealed with a material having a strength that is broken by insertion from above the male joint,
The self-sinking in the soil cement with the water-impervious panel attached to the casting frame, or after self-sinking , the female joint is filled with a filler and has a male joint that engages with the female joint. While self-sinking in the soil cement with the water-impervious panel attached to the casting frame, or after self-sinking , repeat the process of filling the filler in the female joint of the next water-impervious panel,
A method for constructing a water-impervious middle wall characterized in that the casting frame is then pulled up to the ground while injecting grout from the grout injection path. A ruler receiving member is installed on both sides of the soil cement wall, and this ruler receiving member has a roller at the tip of the member protruding in the direction of the thickness center of the soil cement wall and can move along the ruler receiving member. In addition, an insertion ruler member that can be fixed at an arbitrary position is attached, and the placement frame equipped with a water-impervious panel is guided by being regulated by the roller of the insertion ruler member while being suspended by a suspension hook at the upper end. 2. The method for constructing a water-impervious underground wall according to claim 1, wherein the self-sediment is caused by its own weight in soil cement at a predetermined position. The placing frame has a rib on the surface opposite to the surface that supports the water-impervious panel, a hook is provided at the upper end of the rib, and a grout injection path is provided along the rib. The construction method of the water-impervious ground wall according to claim 1 or 2, characterized by the above. Construction method of water shield underground wall according to claim 1 or 2, characterized in that the liquid density of the soil cement used in the construction of underground continuous wall liquid density hereinafter of the filler into the female joint .

Images