JP2004211422A - Impervious-wall construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impervious-wall construction method easily soil-improving the place of an imperfect contact by using a simple device when the imperfect contact is expected for constructing an impervious wall. <P>SOLUTION: In the impervious-wall construction method in which piles (1) are excavated, impervious wall elements (1a) are formed by injecting impervious wall materials (C) into the pits (1) and the impervious walls (10) are built by contacting/continuing the elements (1a). outer pipes (20) for a double packer are inserted previously in side end sections, which are adjoined or may be adjoined to single piles or the elements (1a) in a specified width in the pits (1). The impervious wall materials (C) are injected into the pits (1), injection pipes (30) are inserted into the outer pipes (20) and a soil-improvement agent (C1) is force-fed towards a ground in the vicinity of the contacting sections of the single piles or the elements (1a) in the specified width, which are adjoined or may be adjoined, from the outer pipes (20). <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a seepage control wall construction method, and more specifically, conventionally, a well-constructed, excavating a vertical hole, injecting a seepage control wall material into the vertical hole, or a single pile or The present invention relates to an impermeable wall construction method for forming an impermeable wall element having a predetermined width and contacting and continuing the single pile or impermeable wall element laterally to construct an impermeable wall.
[0002]
[Prior art]
Conventionally, this type of impermeable wall construction method has gained trust as an established technique with many construction examples. However, recently, the required depth of the impermeable wall has become deeper, and slight dimensional errors on the ground to be installed on the ground will increase in deeper parts, resulting in large errors, and the continuity of the impermeable wall cannot be ensured. Mistakes are being reported.
[0003]
That is, when the right vertical hole 1 is excavated in the left existing impermeable wall element 1a shown in FIG. 1, if there is some error in the accuracy of the verticality, the vertical hole 1 is deeply formed in the existing impermeable wall element. It is separated from the element 1a. In addition, in the example of FIG. 4 and FIG. 9, in addition to the verticality error, in the case where the wide vertical hole 1 is slightly twisted, the position indicated by the broken line in FIG. When the vertical hole 1 is excavated, an error occurs in the verticality for some reason as the vertical hole 1 becomes deeper, and the vertical hole 1 is twisted so as to face upward in the figure. When the excavation was attempted to partially overlap the water wall element 1a, the vertical hole 1 was separated from the existing impermeable wall element 1a in a deep part. Therefore, if the single pile or the impermeable wall element 1a is separated in this way, it is impossible to secure water impermeability at this portion at all, and the soil retaining function cannot be expected.
[0004]
Of course, the above construction error is not something that can be left unattended, during construction, or as a result of excavating the vertical hole and measuring it, if an error is found, refill the vertical hole and re-excavate the vertical hole Alternatively, after the completion of a single pile or impermeable wall element, a chemical liquid injection hole is separately excavated from the ground to the vicinity of this poor construction site, and improvement work is performed to inject a ground improvement agent from the ground.
[0005]
Conventionally, a double packer method has been widely used for the improvement work for injecting the ground improvement agent, and one example thereof is described in Patent Document 1. According to the double packer method of Patent Document 1, a double pipe combining a pipe with a sleeve as an outer pipe and an injection pipe as an inner pipe is used as a so-called "injection pipe". In the double pipe double packer method for providing a double packer on the injection pipe, the description is made to state that the double packer method is a known technique. In connection with the present invention, paragraph [0006] of Patent Document 1 also discloses that the sleeve is a rubber (rubber) sleeve that covers the injection nozzle.
[0006]
Patent Document 2 discloses a method for improving the ground below the impermeable wall, which has a different purpose, for example, "Pipes 5 are arranged in the reinforcing cage 3 at predetermined arrangement intervals, for example, in a staggered manner. After the reinforced cage 3 is built in the excavation groove 2 and concrete is poured, the jet bolt 6 is drilled to a formation deeper than the groove bottom of the excavation groove 2 by using the pipes 5 as guides to form a pressurized water-bearing formation E1. Then, the chemical solution 7 is injected from the tip of the jet bolt 6 to the location of the pressurized aquifer E1 and solidified to improve the geology ”.
[0007]
Then, by applying the techniques of Patent Documents 1 and 2 described above, it is possible to improve the ground near the poor construction site, secure water shielding, and secure the earth retaining function. In order to use the double packer method, as shown in FIG. 9, a vertical hole H1 (boring hole) for the double packer is separately excavated, a double packer device is inserted into the vertical hole H1, and a chemical solution is injected. It is necessary to form the improved ground part C1a, and the construction cost is increased, and an extra construction space for excavating the vertical hole H1 for the double packer method is required, and it is not necessarily realized at any construction site. There was a problem that it could not be done.
[0008]
The method of Patent Document 2 has no problem in improving the ground below the impermeable wall, but is not suitable for improving the ground beside the vertical hole 1 as shown in FIGS. 1 and 4. In particular, in the case of the vertical hole 1 having a small diameter, there is a problem that there is no space in the vertical hole 1 for accommodating the long jet bolt described in Patent Document 2 in the lateral direction. are doing.
[0009]
[Patent Document 1] Japanese Patent Application Laid-Open No. 8-31855 (Claims, FIG. 1 and paragraph number “0006”)
[Patent Document 2] JP-A-6-146270 (FIG. 3)
[0010]
[Problems to be solved by the invention]
Therefore, the present invention has been made in view of the above problems, and when poor contact (continuity) is expected in the construction of the impermeable wall, the use of a simple device makes it easy to construct the ground at the poor contact point. It is an object of the present invention to provide a method for constructing a seepage control wall that can be improved appropriately and can guarantee continuous water stoppage.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention excavates the vertical hole 1 and injects the water-blocking wall material C into the vertical hole 1 to form a single pile or a water-blocking wall element 1a having a predetermined width. In the seepage control wall construction method of constructing the seepage control wall 10 by making the single pile or the seepage control wall elements 1a, 1a, 1a... The outer pipe 20 for a double packer is inserted into a side end adjacent to or planned to be adjacent to the water impervious wall element 1a, and the water impervious wall material C is injected into the vertical hole 1, and then the outer pipe The injection pipe 30 is inserted into the inner pipe 20, and the soil improving agent C1 is pumped from the outer pipe 20 to the adjacent ground or a single pile or a ground near the contact area of the impermeable wall element 1a having a predetermined width. Technical measures characterized by the following are taken.
[0012]
Therefore, in the present invention, since the vertical hole 1 for forming the water-impervious wall 10 is also used as the hole into which the outer pipe 20 for the double-packer is inserted, the vertical hole 1 for the double-packer method is separately provided. There is no need to excavate the hole H1 (see FIG. 9), and since the impermeable wall material C is injected into the vertical hole 1, the ground improving agent C1 is pumped, so that the ground improving agent C1 is surely supplied. In addition, it has the function of being able to be pumped and injected into the ground.
[0013]
The operation of pumping the ground improving agent C1 using the outer pipe 20 for the double packer is the same as the operation of the conventional double packer method, and the ground is appropriately fed from the pumping hole (through hole 21) having a desired depth. The present invention has an effect of pumping the improving agent C1 and an effect of pumping the soil improving agent C1 to the same place a plurality of times by changing the type of the soil improving agent C1. The outer pipe 20 is embedded in the impermeable wall material C, and the impermeable wall material C eventually solidifies. However, by adjusting the injection pressure, the impermeable wall material that has solidified or is in the process of being solidified is adjusted. It has the function of splitting the material C and ejecting the ground improvement agent C1 outward.
[0014]
Next, according to the invention of claim 2, the vertical hole 1 is excavated, and the water impermeable wall material C is injected into the vertical hole 1 to form a single pile or a water impermeable wall element 1a having a predetermined width. In the impermeable wall construction method of constructing the impermeable wall 10 by laterally contacting and continuing the piles or impermeable wall elements 1a, 1a, 1a,. An outer pipe 20 for a double packer whose bottom is sealed is inserted into a side end adjacent to or planned to be adjacent to the impermeable wall element 1a, and the outer pipe 20 is vertically pumped to the outer pipe 20 at predetermined intervals. .. Serving as mouths are provided toward the outside of the vertical hole 1, and each of the through holes 21 is covered with a rubber-like sleeve member 23, respectively. The outer band 20 is fastened to the outer tube 20 with the attachment bands 22, 22, and the outer tip side is located at a position matching the through hole 21. The beak-shaped convex portion 24 to be reduced in diameter is formed by bulging. Further, a slit-shaped opening 24a is provided at the tip of the beak-shaped convex portion 24. A pair of injection pipes 30 each of which is capable of inserting and removing the injection pipe 30 and having a pair of seals between the outer peripheral surface of the injection pipe 30 and the inner peripheral surface of the outer pipe 20 above and below the pressure feed port 31 of the injection pipe 30. After installing the packings 32 and 32 and injecting the impermeable wall material C into the vertical hole 1, the injection pipe 30 is moved up and down, and the ground improvement agent C <b> 1 is adjacent or is scheduled to be adjacent to the desired through hole 21. A technical measure characterized in that a single pile or a predetermined width of the impermeable wall element 1a is pressure-fed toward the ground near the contact portion.
[0015]
Therefore, according to the construction method of the present invention, since the through hole 21 serving as the outer tube pressure feed port is covered with the sleeve body 23 in addition to the function of claim 1, the vertical hole 1 in which the outer tube 20 is built is provided. Even if the impermeable wall material C is injected into the inside, or the outer pipe 20 is built in the vertical hole 1 into which the impermeable wall material C is injected, the sealing performance of the through holes 21, 21, 21. It is maintained and exhibits an action of preventing the water-blocking wall material C from entering the outer tube 20. Since the sleeve body 23 is fastened to the outer tube 20 by the fastening bands 22, 22, the sleeve body 23 does not shift even when a large external force is applied, and the ground improvement material C1 is moved outward from the through hole 21 side. When the rubber band 23 is provided with a slit-shaped opening 24a, the opening 24a is pushed open to facilitate the pressure feeding of the ground improvement material C1 through the through hole 21. This allows the backflow of the fluid from the outside of the outer tube 20 toward the inside of the through-hole 21 to be suppressed.
[0016]
Since the beak-shaped protrusion 24 is formed in the sleeve body 23 in advance at a portion corresponding to the through hole 21, the beak-shaped protrusion 24 is directed outward at the side end of the vertical hole 1. At the tip of the beak-shaped protruding portion 24, the water-impervious wall material C is thinner by that amount, and the internal pressure of the ground improvement material C1 fed from the through-hole 21 is reduced to a beak-like shape whose diameter is reduced. Even if the water-impervious wall material C is solidified to have a predetermined strength, the water-impervious wall material C is easily broken by a pressure higher than the inner side even if the water-impervious wall material C is solidified to a predetermined strength. And an effect of allowing outflow of the ground improvement material C1.
[0017]
Next, a third aspect of the present invention is to excavate the vertical hole 1 and inject the water impervious wall material C into the vertical hole 1 to form a single pile or a water impervious wall element 1a having a predetermined width. In the impermeable wall construction method for constructing the impermeable wall 10 by laterally contacting and continuing the piles or impermeable wall elements 1a, 1a, 1a,... A fixed outer pipe 20 for a double packer having a closed bottom is fixedly attached to a single pile or a side end adjacent to or expected to be adjacent to the impermeable wall element 1a having a predetermined width. It is built into the vertical hole 1 together with the material S, and inside the vertical hole 1 is a single pile or a side end portion adjacent to or planned to be adjacent to the impermeable wall element 1a having a predetermined width. A pipe 20 is inserted into the outer pipe 20, and a through hole serving as an outer pipe pressure feeding port is provided at a predetermined interval in the vertical direction. Are provided outside the vertical hole 1, and the through holes 21 are covered with rubber-like sleeves 23, respectively. A beak-shaped convex portion 24 whose outer distal end side is sequentially reduced in diameter is bulged at a position adapted to the through hole 21 while being fastened to the outer tube 20. Is provided with a slit-shaped opening 24a, and an injection pipe 30 having a pressure feed port 31 at a lower portion is removably inserted into the outer pipe 20, and is inserted above and below the pressure feed port 31 of the injection pipe 30. Is mounted with a pair of packings 32, 32 for sealing the gap between the outer peripheral surface of the injection pipe 30 and the inner peripheral surface of the outer pipe 20, and after injecting the water-blocking wall material C into the vertical hole 1, the injection pipe 30 is moved up and down to obtain the desired through hole 2. Further, a technical measure characterized in that the ground improvement agent C1 is pumped toward the ground near the contact portion of the adjacent or planned single pile or the impermeable wall element 1a having a predetermined width is taken. It is a thing.
[0018]
Therefore, according to the method of the present invention, the outer pipe 20 for the double packer is fixed and attached to the reinforcing bar or the core H to be built in the vertical hole 1 in addition to the function of claim 2. With the core material H, the outer tube 20 can be erected at a desired position and fixed.
[0019]
【Example】
Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in the method of constructing a water impermeable wall according to the present invention, a vertical hole 1 is excavated, and a water impermeable wall material C is injected into the vertical hole 1 to form a single pile or a water impermeable wall element 1a having a predetermined width. Establishing the impermeable wall 10 by making the single pile or impermeable wall elements 1a, 1a, 1a... Of course, the excavation of the vertical hole 1 may be performed by a conventional method, and it is of course possible to perform the excavation without any difficulty. However, since the place where the impermeable wall is required is assumed to have a high groundwater level, Usually, moat is impossible.
[0020]
Therefore, excavation of the vertical hole 1 is usually performed by the Venoto method, the reverse method, the earth drill method using a casing tube, and the like. 7 and FIG. 8, FIG. 7A is a vertical hole excavation process of the vertical hole 1, in which a drill rod 101 of an excavator body 100 is rotated, and a bit 102 at a lower end of the drill rod 101 (in the illustrated example, With the triaxial bit, when the center bit is rotated, the bits on both sides are also rotated by the driving force.), And the vertical hole 1 is excavated. The vertical hole 1 during excavation is filled with a stabilizing solution W1 for preventing collapse of the hole wall. The stable solution W1 is sucked up together with the excavated soil from the upper end of the excavating rod 101, and excavated soil is discharged by the sludge discharging device 103. Is removed, the hole is returned to the vertical hole 1, and the drilling rod 101 is successively added to excavate the vertical hole 1 to a desired depth.
[0021]
When the excavation of the vertical hole 1 is completed, the impermeable wall material C is injected into the vertical hole 1 as shown in FIG. The water impervious wall material C is injected from the concrete milk supply device 104 or the like into the vertical hole 1 by inserting the supply tube 105 into the vertical hole 1 and pulling up the supply tube 105 from the bottom of the vertical hole 1. The impermeable wall material C is solidified by using a part of the stabilizing liquid remaining in the vertical hole 1, and the portion of the stable liquid W1 that has overflowed due to the injection of the impermeable wall material C is sequentially determined. Some of the recovered liquid W1 in the vertical hole 1 is collected and exchanged for the impermeable wall material C.
[0022]
Next, usually, as shown in FIG. 7 (c), a core material H is erected in the vertical hole 1 and the impermeable wall material C is solidified to complete the impermeable wall element 1a. The core H is made of H-shaped steel in the illustrated example, and is built into the vertical hole 1 by the crane 106. However, the core H may be omitted. It is also possible to build the core material H before the wall material C is injected.
[0023]
First, the water impermeable wall elements 1a are provided at predetermined intervals as shown in FIG. 8A. In the illustrated example, the water-blocking wall element 1a is formed by excavating the vertical hole 1 with a triaxial bit and using two shaped steels for the core material H. The water-blocking wall element 1a is a single pile having a circular cross section. Even if the cross section is rectangular or oval with a predetermined width, it is of course possible to use the core material H different from the illustrated example.
[0024]
Next, the impervious wall elements 1a, 1a, 1a,... Indicated by broken lines in FIG. It is constructed in the same manner as described above, and the impermeable wall 10 shown in FIG. 8C is completed. It should be noted that the impervious wall element 1a which is pre-installed and the impervious wall element 1a which is to be installed later are partially overlapped so that even if there is some dimensional error, the impervious wall 10 can be continuously impervious to water and soil. The fastening function is not impaired.
[0025]
In the present invention, the outer pipe 20 for the double packer is inserted (built) into the single hole or the side end to be adjacent to the impermeable wall element 1a having the predetermined width in the vertical hole 1. . As the outer tube 20, a conventionally known steel tube, synthetic resin tube, or the like can be used (in the present embodiment, a pipe made of vinyl chloride resin, which is available at a low cost because the outer tube 20 is buried, is used). A through hole 21 serving as a pressure feed port is attached to the outer tube 20 at a desired interval in the vertical direction, and the through hole 21 is closed with a sleeve or O-ring made of a rubber-like body.
[0026]
In the conventional example, the through holes 21 are provided at a plurality of locations in the circumferential direction of the outer tube 20. However, in the present invention, in order to specify the direction of feeding the ground improvement agent C1 described later, the through holes 21 are vertically aligned. It is provided on a line or is juxtaposed in a number of vertical straight lines. The through holes 21 are usually circular, but may be non-circular such as horizontally long through holes to adjust the direction in which the ground improving agent C1 is ejected.
[0027]
The outer pipe 20 is inserted into a single pile or a side end that is adjacent to or planned to be adjacent to the impermeable wall element 1a having a predetermined width. The side of the impermeable wall element 1a having a width (see FIG. 4) may be a single pile to be constructed later or the side of the impermeable wall element 1a having a predetermined width in the pre-constructed vertical hole 1. It is not necessary to always insert the outer pipe 20 into all the vertical holes 1, 1, 1... It is sufficient only when the excavation dimensional error is found or when it is determined to be suspected. In the illustrated example, the outer tube 20 is inserted into only one of the left and right sides of the vertical hole 1 in the figure, but a pair may be inserted into both the left and right sides.
[0028]
Then, after injecting the impermeable wall material C into the vertical hole 1, the injection pipe 30 is inserted into the outer pipe 20, and the ground improvement agent C <b> 1 is adjacent to or is scheduled to be adjacent to the outer pipe 20 from the single pile or It is pumped toward the ground near the contact area of the impermeable wall element 1a having a predetermined width. As the water impervious wall material C, a conventionally known material is used as described above, and either a material that solidifies the stabilizer using part of the stabilizer W1 or a material that replaces the stabilizer W1 may be used.
[0029]
Also, the ground improving agent C1 may be pumped by a conventional method (a conventionally known double packer method) by a conventional method (prior known double packing method). Although it may be any after that, in order for the impermeable wall material C enclosing the outer pipe 20 to be split and the ground improving agent C1 is jetted, the impermeable wall material C starts to solidify. The state before reaching the final strength was most desirable.
[0030]
The injection pipe 30 inserted into the outer pipe 20 can be of course a conventionally known one. The injection pipe 30 has a lower end hermetically sealed and a pressure feed port 31 provided at a lower portion (peripheral wall). A pair of packings 32, 32 (see FIG. 3) for sealing a gap between the outer peripheral surface of the injection pipe 30 and the inner peripheral surface of the outer pipe 20 are mounted above and below the pumping apparatus. The soil improving agent C1 which is further pumped out flows out between the upper and lower packings 32, 32 as shown by arrows A1, A1, A1,... In the pumping port 31 and further shown by arrow A2 in FIG. As described above, it flows out from the through hole 21 of the outer tube 20. Since the injection pipe 30 can be inserted and removed, it is possible to select the height of the through-hole 21 of the outer pipe 20 from which the ground improving agent C1 is to be sent out by moving the injection pipe 30 up and down. .
[0031]
Next, according to the invention of claim 2, the vertical hole 1 is excavated, and the water impermeable wall material C is injected into the vertical hole 1 to form a single pile or a water impermeable wall element 1a having a predetermined width. In the impermeable wall construction method of constructing the impermeable wall 10 by laterally contacting and continuing the piles or impermeable wall elements 1a, 1a, 1a,. Inserting the outer tube 20 for a double packer with a closed bottom into the side end portion adjacent to or planned to be adjacent to the impermeable wall element 1a is the same configuration as in the first aspect.
[0032]
In the present invention, the outer tube 20 is provided with through holes 21, 21, 21... Serving as outer tube pressure feed ports at predetermined intervals in the vertical direction toward the outside of the vertical hole 1. The portions of the through holes 21 are covered with rubber-like sleeve members 23, respectively. The sleeve members 23 are fastened to the outer tube 20 by fastening bands 22, 22, and the outer end is located at a position suitable for the through holes 21. The beak-shaped protrusion 24 whose side is sequentially reduced in diameter is formed by bulging, and further, a slit-shaped opening 24a is provided at the tip of the beak-shaped protrusion 24.
[0033]
That is, it is possible to prevent the through holes 21, 21, 21,... Of the outer tube 20 from being covered with the sleeve body 23, and to prevent foreign matters from being mixed into the outer tube 20 and hindering the elevation of the injection tube 30. Although conventionally known, in the present invention, in order to embed the outer pipe 20 in the impermeable wall material C, the injection pipe 30 is inserted into the highly viscous impermeable wall material C, or the injection pipe 30 inserted in advance is used. When the water-impervious wall material C is injected around the periphery, a large external force is applied to the step portion due to the thick portion of the sleeve body 23, and the sleeve body 23 is rolled up and the sealing property cannot be ensured. The part to be a part is firmly tightened by the fastening bands 22, 22 to prevent the sleeve body 23 from shifting or rolling up.
[0034]
The two rubber-like sleeves 23 are formed by bulging a beak-shaped convex portion 24 whose outer distal end is sequentially reduced in diameter at a position suitable for the through-hole 21. Is provided with a slit-shaped opening 24a, and it is of course possible to integrally mold such a shape. However, since the shape is unexpectedly complicated to integrally mold, it is developed in the present invention and FIG. As shown in FIG. 6, a belt-shaped main body 23 a partly protruding is formed, and the length (length in the left-right direction in the figure) of the band-shaped main body 23 a is made to match the outer peripheral length of the outer tube 20. The sleeve 23 a is wound around the outer tube 20 so that it can be used as the sleeve body 23.
[0035]
Further, a longitudinal half side 24 'of the beak-shaped protrusion 24 is formed at one end of the band-shaped main body 23a by bulging, and the remaining longitudinal half 24' of the beak-shaped protrusion 24 is formed at the other end. When the band-shaped main body 23a is swelled and wound around the outer tube 20, the joining portions at both ends are located in a columnar shape of the through-hole 21, so that the pair of vertical half sides 24 ', 24' is formed. The beak-shaped protrusion 24 is adapted to the position of the through hole 21. In addition, by joining both side edges 23b and 23c of the band-shaped main body 23a, the joining portion becomes the slit-shaped opening 24a described above.
[0036]
Next, according to the invention of claim 3, a vertical hole 1 is excavated, and a water impervious wall material C is injected into the vertical hole 1 to form a single pile or a water impervious wall element 1a having a predetermined width. In the impermeable wall construction method for constructing the impermeable wall 10 by laterally contacting and continuing the piles or impermeable wall elements 1a, 1a, 1a,... A fixed outer pipe 20 for a double packer having a closed bottom is fixedly attached to a single pile or a side end adjacent to or expected to be adjacent to the impermeable wall element 1a having a predetermined width. It is built into the vertical hole 1 together with the material S, and inside the vertical hole 1 is a single pile or a side end portion adjacent to or planned to be adjacent to the impermeable wall element 1a having a predetermined width. A pipe 20 is inserted into the outer pipe 20, and a through hole 2 serving as an outer pipe pressure feed port is provided at a predetermined interval in the vertical direction. , 21, 21... Are provided toward the outside of the vertical hole 1, and the respective through holes 21 are covered with rubber-like sleeve members 23, respectively. A beak-shaped convex portion 24 whose outer distal end is sequentially reduced in diameter is bulged at a position adapted to the through-hole 21 while being fastened to the outer tube 20. Is provided with a slit-shaped opening 24a, and an injection pipe 30 having a pressure supply port 31 at a lower portion is removably inserted into the outer pipe 20, and an upper portion and a lower portion of the injection port 30 of the injection pipe 30 are provided. A pair of packings 32, 32 for sealing the gap between the outer peripheral surface of the injection pipe 30 and the inner peripheral surface of the outer pipe 20 are mounted, and after the water blocking wall material C is injected into the vertical hole 1, the injection pipe 30 Is moved up and down to obtain the desired through-hole 21. Ri, in which none to pump toward the ground improvement agent C1 to ground in the vicinity of the contact portion of impervious wall element 1a of the single pile or a predetermined width to schedule adjacent or neighboring.
[0037]
That is, according to the present invention, the outer tube 20 of the second aspect is fixed to a reinforcing bar or a core H to be built in the vertical hole 1 so that the outer tube 20 can be built in the vertical hole 1 together with the core H. Things. The fixing of the outer tube 20 to the core material H may be performed by tightening with a wire, or, although not shown, a conventionally known cylindrical holder such as a gutter support is used as the core material H in advance. It may be attached and held by this cylindrical holder.
[0038]
【The invention's effect】
According to the invention of claims 1 to 3, even if an error occurs in the excavation work of the vertical hole 1, in particular, without performing new excavation, the ground portion of the discontinuous portion of the impermeable wall is improved, It is an object of the present invention to provide a method for constructing a water-impervious wall that can guarantee the water-impermeability and earth retaining function.
[0039]
In particular, according to the second and third aspects of the present invention, the beak-shaped protrusion 24 is formed in advance in the sleeve body 23 at a position corresponding to the through-hole 21 by bulging. 1 at the side end, the water-impervious wall material C is thinner at the tip of the beak-shaped protrusion 24, and the internal pressure of the ground improvement material C1 pumped through the through hole 21. Is gradually increased toward the distal end side of the beak-shaped protrusion 24 whose diameter is reduced toward the front, and even if the impermeable wall material C is solidified to form the impermeable wall element 1a having a predetermined strength, A water wall construction method capable of easily breaking the impermeable wall material C with a greater pressure than the inside, allowing the ground improvement material C1 to flow out, and reliably pumping the ground improvement material C1 in the desired direction. It can be provided.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing steps of a method for constructing a seepage control wall of the present invention.
FIG. 2 is a partial cross-sectional view of an impermeable wall construction method according to the present invention with an outer pipe inserted.
FIG. 3 is a longitudinal sectional view of an embodiment of the double packer used in the present invention.
FIG. 4 is a cross-sectional view of a part where the ground has been improved by the water wall construction method of the present invention.
FIG. 5 is an exploded front view of one embodiment of a sleeve used in the present invention.
FIG. 6 is a right side view of the sleeve body.
FIG. 7 is a partial cross-sectional front view for explaining a construction procedure of the impermeable wall element.
FIG. 8 is a plan view for explaining a construction procedure of a water-blocking wall element.
FIG. 9 is a cross-sectional view of a portion where the ground has been improved in the conventional example.
[Explanation of symbols]
1 vertical hole
C impermeable wall material
1a Impermeable wall element
10 impermeable wall
S core material
20 outer tube
30 Injection tube
21 through hole
22 Fastening band
23 Sleeve body
24 beak-shaped protrusion
24a opening
31 Pressure port
32 Packing
C1 ground improvement agent

Claims (3)

A vertical hole (1) is excavated, and a water impervious wall material (C) is injected into the vertical hole (1) to form a single pile or a water impervious wall element (1a) having a predetermined width. In the impermeable wall construction method of constructing the impermeable wall (10) by contacting and continuing the impermeable wall elements (1a, 1a, 1a ...) in the lateral direction,
In the vertical hole (1), an outer pipe (20) for a double packer is inserted in a single pile or a side end that is adjacent or planned to be adjacent to the impermeable wall element (1a) having a predetermined width,
After injecting the impermeable wall material (C) into the vertical hole (1), an injection pipe (30) is inserted into the outer pipe (20), and the ground improving agent (C1) is inserted through the outer pipe (20). Characterized by the fact that pressure is fed toward the ground near the contact area of a single pile or a predetermined width of the impermeable wall element (1a) adjacent or scheduled to be adjacent. A vertical hole (1) is excavated, and a water impervious wall material (C) is injected into the vertical hole (1) to form a single pile or a water impervious wall element (1a) having a predetermined width. In the impermeable wall construction method of constructing the impermeable wall (10) by contacting and continuing the impermeable wall elements (1a, 1a, 1a ...) in the lateral direction,
An outer tube (20) for a double packer with a closed bottom is inserted into a side end of the vertical hole (1) adjacent or expected to be adjacent to the single pile or the impermeable wall element (1a) having a predetermined width. The outer tube (20) is provided with through holes (21, 21, 21...) Serving as outer tube pressure feed ports at predetermined intervals in the vertical direction toward the outside of the vertical hole (1). Each of the through holes (21) is covered with a rubber-like sleeve (23), and the sleeve (23) is fastened to the outer tube (20) by fastening bands (22, 22). A beak-shaped convex portion (24) whose outer distal end side is sequentially reduced in diameter is bulged at a position suitable for the through hole (21), and a slit-shaped convex portion is formed at the distal end of the beak-shaped convex portion (24). Opening (24a) is provided,
Into the outer pipe (20), an injection pipe (30) having a pressure feed port (31) at its lower part is removably inserted, and above and below the pressure feed port (31) of the injection pipe (30). A pair of packings (32, 32) for sealing a gap between an outer peripheral surface of the injection pipe (30) and an inner peripheral face of the outer pipe (20) are attached;
After injecting the impermeable wall material (C) into the vertical hole (1), the injection pipe (30) is raised and lowered, and the ground improvement agent (C1) is adjacent or adjacent to the desired through hole (21). A method for constructing a seepage control wall, characterized in that the pumping is carried out toward a ground near a contact portion of a single pile or a seepage control wall element (1a) having a predetermined width. A vertical hole (1) is excavated, and a water impervious wall material (C) is injected into the vertical hole (1) to form a single pile or a water impervious wall element (1a) having a predetermined width. In the impermeable wall construction method of constructing the impermeable wall (10) by contacting and continuing the impermeable wall elements (1a, 1a, 1a ...) in the lateral direction,
The bottom was sealed in a side end portion of the reinforcing rod cage or the core material (S) to be built in the vertical hole (1) adjacent to or planned to be adjacent to the single pile or the impermeable wall element (1a) having a predetermined width. An outer tube (20) for a double packer is fixed and attached, and the outer tube (30) is built together with the core material (S) into the vertical hole (1),
An outer tube (20) for a double packer with a closed bottom is inserted into a side end of the vertical hole (1) adjacent or expected to be adjacent to the single pile or the impermeable wall element (1a) having a predetermined width. The outer tube (20) is provided with through holes (21, 21, 21...) Serving as outer tube pressure feed ports at predetermined intervals in the vertical direction toward the outside of the vertical hole (1). Each of the through holes (21) is covered with a rubber-like sleeve (23), and the sleeve (23) is fastened to the outer tube (20) by fastening bands (22, 22). A beak-shaped convex portion (24) whose outer distal end side is sequentially reduced in diameter is bulged at a position suitable for the through hole (21), and a slit-shaped convex portion is formed at the distal end of the beak-shaped convex portion (24). Opening (24a) is provided,
Into the outer pipe (20), an injection pipe (30) having a pressure feed port (31) at its lower part is removably inserted, and above and below the pressure feed port (31) of the injection pipe (30). A pair of packings (32, 32) for sealing a gap between an outer peripheral surface of the injection pipe (30) and an inner peripheral face of the outer pipe (20) are attached;
After injecting the impermeable wall material (C) into the vertical hole (1), the injection pipe (30) is raised and lowered, and the ground improvement agent (C1) is adjacent or adjacent to the desired through hole (21). A method for constructing a seepage control wall, characterized in that the pumping is carried out toward a ground near a contact portion of a single pile or a seepage control wall element (1a) having a predetermined width.

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