JP5210849B2 - Ground improvement chemical injection method and apparatus - Google Patents

Description

  The present invention relates to a method and an apparatus for injecting a ground improvement chemical solution, and more specifically, even when the injection pressure is increased, the ground improvement chemical solution is not allowed to enter only a specific area, and is stably stabilized over a wide range. The present invention relates to a method and apparatus for injecting a ground improvement chemical solution that can be injected.

  Conventionally, in order to strengthen the ground, various methods for injecting a ground improvement chemical into the target ground using a double tube having a packer have been proposed (for example, see Patent Document 1). In patent document 1, the ground improvement chemical | medical solution is inject | poured with the double tube which provided the packer in each of the outer tube | pipe and the inner tube | pipe. The packer provided in the outer tube expands to pack (seal) the gap between the inner peripheral surface of the insertion hole and the outer peripheral surface of the outer tube after the casing is pulled out. As a result, when the ground improvement chemical solution supplied from the supply port between the two packers provided in the inner pipe is injected into the ground through the slit of the outer pipe, the ground improvement chemical liquid is injected into the inner peripheral surface of the insertion hole and the outer pipe. The liquid is prevented from flowing out through the gap with the outer peripheral surface of the gas and injected into the target area.

  However, in this proposed method, the packer provided in the outer tube expands by the packer grout material injected into the inner tube and presses against the inner peripheral surface of the insertion hole. Therefore, depending on the shape (state) of the inner peripheral surface of the insertion hole. May not be able to seal the gap sufficiently. In addition, the packer provided in the outer pipe has water permeability, but since the amount of the packer grout material that passes through the packer and penetrates the ground is not large, the packer grout material that has passed through the packer causes the insertion hole and It cannot be expected to seal the gap with the outer tube. Therefore, there is still room for improvement in order to prevent the injected ground improvement chemical from flowing out through the gap between the outer tube and the insertion hole.

  Furthermore, when the strength of the inner peripheral surface of the insertion hole is low (weak ground), etc., the inner peripheral surface of the insertion hole collapses due to the pressure contact of the expanding packer, rather, the gap between the insertion hole and the outer tube is broken. There was a problem that it was difficult to seal.

Also, if you try to inject the ground improvement chemical solution over a wide area and increase the injection pressure, the ground improvement chemical solution discharged from the slit of the outer tube will penetrate into the specific area with relatively weak ground, rather, There is a problem that the injection range becomes narrow.
JP 2005-314938 A

  An object of the present invention is to provide a ground improvement chemical solution injection method and apparatus capable of stably injecting a ground improvement chemical solution into a specific area without causing the ground improvement chemical solution to enter only a specific region even when the injection pressure is increased. There is to do.

  In order to achieve the above object, the ground improvement chemical solution injection method of the present invention inserts an outer tube having a plurality of injection holes provided in the peripheral wall in the axial direction into an insertion hole formed in the ground. Insert the inner tube into the tube to a predetermined position, expand the two inflatable packers spaced apart in the axial direction on the surface of the inner tube, and press the inner tube on the inner peripheral surface of the outer tube, A method of injecting a ground improvement chemical solution by supplying a ground improvement chemical solution from a discharge port provided on a peripheral wall of an inner tube located between the two inflated packers and injecting the ground improvement solution from an injection port of an outer tube. The surface of the outer tube is provided with two inflatable outer tube packers spaced apart in the axial direction across at least one injection port, and the inlet located at a position different from the position where the outer tube packer is provided Is covered with a porous coating, and the contracted outer tube packer is inserted. It is expanded so that it has a gap with the inner peripheral surface of the hole, and the instantaneous setting solidified liquid is injected into the ground from the inlet located between the expanded outer tube packers, and the instantaneous setting around the inlet A packer made of a solidified liquid is formed, and then a ground improvement chemical solution is injected into the ground from the injection port covered with the porous coating material.

  Here, an inner tube different from the inner tube is inserted into the outer tube, and two inflatable and retractable packers provided on the surface of the other inner tube so as to be spaced apart in the axial direction are inflated. The solidified liquid is supplied from the discharge port provided in the peripheral wall of the inner tube located between the two inflated packers in a state of being pressed against the peripheral surface, and the ground is supplied from the injection port of the outer tube. It is possible to insert the inner tube for supplying the ground improvement chemical solution into the outer tube by pulling out the inner tube after forming the packer made of the instantaneous solidifying solution. Alternatively, the two expandable packers provided on the surface of the inner tube and spaced apart in the axial direction are inflated and pressed against the inner peripheral surface of the outer tube, and the two expanded packers are expanded. After supplying the instantaneous solidifying liquid from the discharge port provided on the peripheral wall of the inner pipe located between, and injecting into the ground from the inlet of the outer pipe, after forming a packer made of the instantaneous solidifying liquid, this The ground improvement chemical can also be supplied through the inner pipe.

  In the ground improvement chemical liquid injection method of the present invention, when the instantaneous solidifying liquid is supplied from the discharge port provided in the peripheral wall of the inner tube located between the two inflated packers, the supplied instantaneous settling is performed. The outer tube packer is expanded to fill the inner tube with the internal solid surface of the insertion hole and the supply port located between the expanded outer tube packer. It is also possible to inject an instantaneous solidifying liquid into the ground. Further, the insertion hole can be formed in the horizontal direction by changing its direction in the middle.

  The ground improvement chemical solution injection device according to the present invention includes an outer tube to be inserted into an insertion hole cut in the ground, an inner tube to be inserted into the outer tube and movable in the axial direction, and an instantaneous setting property. An inner pipe for supplying a solidified liquid, and a plurality of injection ports communicating with the inner side and the outer side of the pipe are formed in the peripheral wall of the outer pipe so as to be separated from each other in the axial direction; Two inflatable outer tube packers are provided, and at least one inlet is arranged between the two outer tube packers, and the inlet at a position different from the position where the outer tube packer is provided is porously coated And a gap adjusting means for adjusting the gap between the inner peripheral surface of the insertion hole when each of the two outer pipe packers is expanded, and a shaft is provided on the surface of each of the inner pipes. With two inflatable packers spaced apart in the direction In which characterized in that a discharge opening in the peripheral wall of the inner tube between the two collapsible packer.

  Further, another ground improvement chemical solution injection device according to the present invention comprises an outer tube inserted into an insertion hole cut in the ground, and an inner tube inserted into the outer tube and movable in the axial direction. A plurality of inlets communicating with the tube inner side and the tube outer side are formed apart from each other in the axial direction, and two inflatable outer tube packers are provided on the outer tube surface in the axial direction. At least one inlet is disposed between the two outer tube packers, and the inlet at a position different from the position where the outer tube packer is provided is covered with a porous coating material, and each of the two outer tube packers is covered. Provided with a gap adjusting means for adjusting so as to have a gap between the inner peripheral surface of the insertion hole when expanded, and provided with two inflatable / retractable packers spaced in the axial direction on the surface of the inner tube, Discharge port placed on the peripheral wall between the two packable packers And it is characterized in that a switching means for supplying switching the ground improvement chemical and Madokayui solidification liquid in the inner tube.

  In the ground improvement chemical solution injection device according to the present invention, an injection port is provided on the surface of the outer tube at the position where the two expandable outer tube packers are provided. It is also possible to fill the expandable outer tube packer with the coagulating solidified liquid and expand it. The outer tube and the inner tube are, for example, flexible.

  According to the present invention, in the insertion hole drilled in the ground, the outer tube having a plurality of inlets provided in the peripheral wall and spaced apart in the axial direction is inserted, and then the inner tube is inserted into the outer tube to a predetermined position, Two inflatable packers that are spaced apart in the axial direction on the surface of the inner tube are inflated and pressed against the inner peripheral surface of the outer tube, and between the two inflated packers. When the ground improvement chemical solution is supplied from the discharge port provided in the peripheral wall of the inner tube and is injected into the ground from the injection port of the outer tube, the inflatable outer tube packer provided on the surface of the outer tube is used to instantly By forming the packer with the coagulating solidified liquid, the gap between the inner peripheral surface of the insertion hole and the outer peripheral surface of the outer tube can be reliably sealed. At that time, since the outer tube packer is expanded so as to have a gap with the inner circumferential surface of the insertion hole, the inner circumferential surface of the insertion hole is not pressed and broken by the outer tube packer. Therefore, when injecting the ground improvement chemical liquid into the ground from the injection port located at a position different from the packer formed by the instantaneous setting solidified liquid, the gap between the inner peripheral surface of the insertion hole and the outer peripheral surface of the outer tube The outflow of ground improvement chemicals can be suppressed.

  In addition, by injecting the ground improvement chemical liquid into the ground from the injection port covered with the porous coating material, even if the injection pressure is large, the ground improvement chemical liquid is spread over a wide range while being appropriately decompressed by the porous coating material. . As a result, even when the injection pressure is increased, the ground improvement chemical solution does not enter the specific area where the ground is relatively weak so as to tear the ground. It becomes possible to inject the improved chemical solution.

    Hereinafter, a ground improvement chemical solution injection method and apparatus according to the present invention will be described based on embodiments. First, the case where the insertion hole formed by drilling the ground up and down is used will be described as an example.

  As illustrated in FIGS. 1 to 3, the ground improvement chemical liquid injection device (hereinafter referred to as an injection device) of the present invention includes an outer tube 3 inserted into an insertion hole S formed by drilling the ground, The inner tube 5A is inserted into the outer tube 3 and is movable in the outer tube axial direction. The inner pipe 5A supplies the instantaneous solidifying liquid C. Further, apart from the inner pipe 5A, as illustrated in FIGS. 6 and 7, an inner pipe 5B that is inserted into the outer pipe 3 and supplies a ground improvement chemical solution G that is movable in the outer pipe axial direction is provided. Yes.

  The insertion hole S is formed, for example, by extending a casing rod from a drilling machine. After inserting the outer tube 3 into the casing rod inscribed in the insertion hole S, the outer tube 3 is pulled out to the ground. Can be set in the insertion hole S. An expandable anchor is provided at the distal end of the outer tube 3, and the anchor is expanded beyond the inner diameter of the casing rod at a position protruding from the distal end of the casing rod to fix the outer tube 3 to the ground, and then the casing. Pull out the rod.

  In the peripheral wall of the outer tube 3, a plurality of injection ports 3 a that communicate the inner side and the outer side of the tube are formed apart from each other in the outer tube axis direction. Further, two inflatable outer tube packers 11 are provided on the surface of the outer tube 3 so as to be separated from each other in the outer tube axial direction. The two outer tube packers 11 are arranged such that at least one injection port 3a exists on the peripheral wall of the outer tube 3 between them. Examples of the outer tube packer 11 include a swelling material that absorbs moisture and expands, or a sealing material that can be expanded and contracted by a fluid pressure of gas or liquid flowing into and out of the inside.

  The two outer tube packers 11 are configured to have a gap between the inner peripheral surface of the insertion hole S when expanded. That is, there is a gap adjusting means for adjusting so that a gap is formed between the outer tube packer 11 and the inner peripheral surface of the insertion hole S when the outer tube packer 11 is expanded. As the gap adjusting means, it can be exemplified that the specification of the outer tube packer 11 itself is set so as to have a gap with the inner peripheral surface of the insertion hole S when it is expanded to the maximum. Examples of the other gap adjusting means include a flow rate adjusting means for fluid supplied to expand the outer tube packer 11, a fluid pressure adjusting means, a check valve 12 described later, and a combination thereof.

  The lower limit of the size of the gap between the expanded outer tube packer 11 and the inner peripheral surface of the insertion hole S is only required to allow the quick setting solidified liquid C to pass, and the upper limit is 1.0 cm, preferably about 0.5 cm. Therefore, if the expanded outer tube packer 11 is in contact with the inner peripheral surface of the insertion hole S without being in pressure contact, and the instantaneous solidifying liquid C can pass through, it corresponds to the gap of the present invention.

  A porous coating material 10 is provided on the surface of the outer tube 3 at a position different from the position where the outer tube packer 11 is provided. The inlet 3 a in the region where the porous coating material 10 is provided is covered with the porous coating material 10.

  In the present invention, the two-liquid type instantaneous solidification liquid C is injected into the ground through the injection port 3 a disposed between the outer tube packers 11, and the ground improvement chemical solution G is injected through the injection port 3 a covered with the porous coating material 10. Is injected into the ground. Examples of the ground improvement chemical solution G include water glass grout and cement grout. The solidification time from liquid to solidification (gelation) is, for example, about one day. The two-liquid type instantaneous solidifying liquid C is a liquid that rapidly solidifies by, for example, mixing C1 liquid and C2 liquid, and has a solidification time of about 5 to 30 seconds. Examples of the quick setting solidified liquid C include water glass grout, plastic grout and the like.

  The inlet 3a has a diameter of about 3 mm to 10 mm, for example, and the number thereof is appropriately determined. For example, the area between the outer tube packer 11 and the porous coating material 10 is three to three. About 8 are provided.

  The porous coating material 10 has a large number of through-holes having an area smaller than that of the injection port 3a, and is formed of resin, metal, or the like. Examples of the form of the porous coating material 10 include a net-like body such as a resin mesh and a metal mesh, and a porous plate. The thickness of the porous coating material 10 is set to about 0.2 mm to 1.0 mm, for example, and a specification having a large number of minute through holes is preferable.

  As the porous coating material 10, a cylindrical knitted body formed by braiding resin fibers can also be used. For example, a plurality of nylon resin fibers having a wire diameter of about 0.1 mm to 0.5 mm are juxtaposed to form a belt-like body, and the plurality of belt-like bodies are knitted at a predetermined braiding angle to form a cylinder.

  In this embodiment, a cylindrical body whose tip is sealed is used as the outer tube 3, and the injection port 3 a formed at the tip is covered with the porous coating material 10. Then, the injection port 3a located on the rear end side of the region covered with the porous coating material 10 is wound around the surface of the outer tube 3 so that the two outer tube packers 11 are sandwiched in the front-rear direction (in the outer tube axial direction). Yes. The outer diameter of the outer tube 3 is, for example, about 40 mm to 50 mm, and the thickness of the peripheral wall is about 2 mm to 5 mm.

  The inner pipe 5A has two inflatable / expandable packers 6a spaced on the surface thereof in the inner pipe axis direction, and C1 of the instantaneous solidification liquid C is formed on the peripheral wall between the two inflatable / defensible packers 6a. A first discharge port 5a for supplying a liquid and a second discharge port 5b for supplying a C2 liquid are arranged. The inside of the inner pipe 5A is divided into two as illustrated in FIG. 2, and there are two flow paths: a first solidified liquid flow path 7a through which the C1 liquid flows and a second solidified liquid flow path 7b through which the C2 liquid flows. It has a formed structure. The first discharge port 5a and the second discharge port 5b are formed so that the discharge destinations are close to each other.

  Inside the inner pipe 5A, packer expansion pipes 8a are extended in the inner pipe axis direction and connected to the respective packers 6a. The packer 6a is formed of a hollow elastic body such as rubber that can be expanded and contracted, expands by inflow of fluid through the packer expansion pipe 8a, and contracts by outflow of fluid.

  As shown in FIGS. 6 and 7, the other inner tube 5B has two inflatable and contractible packers 6b spaced on the surface thereof in the inner tube axis direction. A third discharge port 5c for supplying the ground improvement chemical solution G is disposed on the peripheral wall. The inside of the inner pipe 5B is a chemical solution flow path 7c through which the ground improvement chemical solution G flows.

  Inside the inner pipe 5B, packer expansion pipes 8b extend in the inner pipe axis direction and are connected to the respective packers 6b. The packer 6b is formed of a hollow elastic body that can be expanded and contracted, such as rubber. The packer 6b expands by inflow of fluid through the packer expansion pipe 8b and contracts by outflow of fluid.

  In this embodiment, a cylindrical body whose tip is sealed is used as the inner tubes 5A and 5B.

  When the ground is improved and strengthened by the ground improvement chemical solution G, the outer tube 3 is inserted into the insertion hole S drilled up and down as illustrated in FIG. Then, the contracted outer tube packer 11 is inflated so as to have a gap with the inner peripheral surface of the insertion hole S as illustrated in FIG.

  Next, the first discharge port 5a and the second discharge port 5b of the inner tube 5A inserted in the outer tube 3 are aligned with the position of the injection port 3a between the two expanded outer tube packers 11. Position. During this positioning, the packer 6a is kept in a contracted state.

  After the positioning, as illustrated in FIG. 5, the packer 6 a is inflated so as to be in pressure contact with the inner peripheral surface of the outer tube 3. In this state, the C1 liquid is supplied from the first discharge port 5a, and the C2 liquid is supplied from the second discharge port 5b. Thereby, C1 liquid and C2 liquid are mixed and it becomes the quick setting solidification liquid C. Since the first discharge port 5a and the second discharge port 5b are sandwiched between the two expanded packers 6a, the C1 liquid and the C2 liquid are separated from the inner peripheral surface of the outer tube 3 and the outer peripheral surface of the inner tube 5A. There is no leakage in the gap.

  Immediately before being injected into the ground in this way, the instantaneous solidifying liquid C obtained by mixing the C1 liquid and the C2 liquid is injected into the ground through the inlet 3a located between the two expanded packers 6a. Since the injection port 3a for injecting the instantaneous solidifying liquid C is sandwiched between the two outer tube packers 11, the instantaneous solidifying liquid C is guided between the two outer tube packers 11 to the ground. To penetrate.

  Here, since there is a predetermined gap between each outer tube packer 11 and the inner circumferential surface of the insertion hole S, the outer tube packer 11 does not press the inner circumferential surface of the insertion hole S. Therefore, even when the strength of the inner peripheral surface of the insertion hole S is low (weak ground) or the like, the inner peripheral surface of the insertion hole S is not collapsed by the expanding outer tube packer 11.

  Moreover, since the instantaneous setting solidified liquid C also circulates outside the outer tube packer 11 through this gap, the instantaneous setting solidified liquid C can be permeated into a wider area of the ground. On the other hand, since the clearance between the inner peripheral surface of the insertion hole S and the outer peripheral surface of the outer tube 3 is smaller than when the outer tube packer 11 is not expanded, the outer tube packer 11 and the inner peripheral surface of the insertion hole S The instantaneous solidifying liquid C does not flow out excessively through the gap (about 1.0 cm at the maximum). Therefore, the instantaneous setting solidified liquid C can be surely penetrated into the ground and rapidly solidified to form a strong packer P around the inlet 3a.

  Thereby, the gap between the inner peripheral surface of the insertion hole S and the outer peripheral surface of the outer tube 3 can be reliably sealed by the packer P formed of the instantaneous setting solidified liquid C. In particular, when the first discharge port 5a and the second discharge port 5b formed so that the discharge destinations are close as illustrated in FIG. 2 are mixed so that the C1 liquid and the C2 liquid collide, It becomes easy to mix each other uniformly.

  Next, the packer 6a is contracted, the inner tube 5A is pulled out from the outer tube 3, and another inner tube 5B is inserted into the outer tube 3 as illustrated in FIG. And it positions so that the 3rd discharge port 5c may be united with the position of the injection port 3a covered with the porous coating material 10. FIG. During this positioning, the packer 6b is kept in a contracted state.

  After the positioning, the packer 6 b is expanded by the fluid supplied through the packer expansion pipe 8 b illustrated in FIG. 7 and is brought into pressure contact with the inner peripheral surface of the outer tube 3. In this state, as shown in FIG. 8, the ground improvement chemical G is supplied from the third discharge port 5c. Since the third discharge port 5c is sandwiched between the two expanded packers 6b, the ground improvement chemical G does not flow out between the inner peripheral surface of the outer tube 3 and the outer peripheral surface of the inner tube 5B. .

  The supplied ground improvement chemical solution G is injected into the ground through the injection port 3a. Even if the ground improvement chemical solution G to be injected flows out between the inner peripheral surface of the insertion hole S and the outer peripheral surface of the outer tube 3, The outflow is blocked by the packer P. Moreover, when the ground improvement chemical | medical solution G is inject | poured into a ground, it passes the porous coating | covering material 10 which covers the injection port 3a. Therefore, even if the injection pressure is large, the pressure is reduced moderately by the porous coating material 10 so that the ground improvement chemical solution G does not simply go straight from the injection port 3a in the direction orthogonal to the outer tube axis (horizontal direction) but spread over a wide range. Become.

  As described above, even when the injection pressure is increased, the ground improvement chemical solution G does not enter the specific area of the relatively weak ground so as to tear the ground, as illustrated in FIG. It becomes possible to inject the ground improvement chemical solution G stably over a wide area of the ground.

  When the ground improvement chemical solution G is injected into the ground at another height position, the outer tube packer 11 and the porous coating material 10 described above are also provided at another height position of the outer tube 3. Then, the inner pipes 5A and 5B inserted into the outer pipe 3 are sequentially moved to appropriate positions, and the same procedure as described above is performed.

  When a cylindrical knitted body made of resin fibers is used as the porous coating material 10, the ground improvement chemical solution G passes through the gaps between the resin fibers and is injected into the ground. In this case, the resin fibers are knitted so as to cross each other up and down, and since the ground improvement chemical solution G also passes through the gaps between the resin fibers that are overlapped with each other, the injection pressure is easily equalized and stably spread over a wide range. It is further advantageous to spread the ground improvement chemical solution G.

  In the above-described embodiment, the instantaneous setting solidified liquid C and the ground improvement chemical liquid G are supplied using different inner pipes 5A and 5B. However, as illustrated in FIG. Moreover, the instantaneous setting solidified liquid C and the ground improvement chemical | medical solution G can also be supplied. This inner tube 5C is provided with a switching means 9 for switching and supplying the ground improvement chemical solution G and the instantaneous solidifying solution C to the inner tube 5A shown in FIG. The switching means 9 is installed on the ground, and a pipe extending from the switching means 9 is connected to the rear end portion of the inner pipe 5C.

  When this inner tube 5C is used, until the packer P is formed by the instantaneous solidifying liquid C, the instantaneous solidifying liquid C (C1 liquid, C2 liquid) is supplied to the inner pipe 5C by the setting of the switching means 9. The same procedure as in the above embodiment is performed. Thereafter, when the ground improvement chemical solution G is injected into the ground, the setting of the switching means 9 is switched to supply the ground improvement chemical solution G to the inner pipe 5C. That is, the first solidified liquid flow path 7a and the second solidified liquid flow path 7b are switched to the chemical liquid flow path 7c, and the inner tube 5C is moved in the outer tube axis direction to be positioned at a predetermined position. And the 1st discharge port 7a and the 2nd discharge port 7b are functioned as the 3rd discharge port 7c, the ground improvement chemical | medical solution G is supplied, and the ground improvement chemical | medical solution G is supplied to the ground from the injection port 3a covered with the porous coating material 10. inject.

  The present invention uses not only the insertion hole S formed in the vertical direction as in the above embodiment, but also the insertion hole S inclined in the oblique direction or the insertion hole S bent in the middle and formed in the horizontal direction. It can also be applied to cases. When the ground on which the structure is erected is improved and strengthened, the insertion hole S is bent in the middle and formed in the horizontal direction. In this case, as illustrated in FIG. 11, the casing rod 2 is obliquely extended from the drilling machine 1 to drill the ground, and the drilling direction is changed to horizontal in the middle, and the insertion hole is inserted into the ground below the structure 13. S is formed.

  Next, as illustrated in FIG. 12, the outer tube 3 having the anchor 4 at the tip is inserted into the casing rod 2 inscribed in the insertion hole S. The anchor 4 is formed of a hollow elastic body such as rubber, for example. In this embodiment, since the insertion hole S is bent, it is preferable to use the outer tube 3 and the inner tubes 5A and 5B excellent in flexibility.

  Next, as illustrated in FIG. 13, a fluid is supplied to the inside of the anchor 4 that protrudes from the tip of the casing rod 2, and is expanded larger than the inner diameter of the casing rod 2 to fix the outer tube 3 to the ground. Thereafter, the casing rod 2 is pulled out to the ground. Thereby, a gap is formed between the inner peripheral surface of the insertion hole S from which the casing rod 2 has been pulled out and the outer peripheral surface of the outer tube 3. In addition, a filler such as cement bentonite can be filled in advance between the inner peripheral surface of the insertion hole S and the outer peripheral surface of the outer tube 3.

  Next, as in the previous embodiment, the inner tube 5A is inserted into the outer tube 3, the first discharge port 5a and the second discharge port 5b are positioned at predetermined positions, and are expanded as illustrated in FIG. Then, the instantaneous setting solidified liquid C is injected into the ground from the inlet 3a located between the outer tube packers 11, and the packer P made of the instantaneous setting solidified liquid C is formed around the inlet 3a. Next, the inner tube 5A is moved in the outer tube axis direction, the first discharge port 5a and the second discharge port 5b are positioned at different predetermined positions, and the packer P is formed at another position by the same procedure. In this way, the packer P is formed so as to sandwich the inlet 3a covered with the porous coating material 10 in the outer tube axis direction.

  Next, as in the previous embodiment, the inner tube 5 </ b> A is pulled out from the outer tube 3, and another inner tube 5 </ b> B is inserted into the outer tube 3. Then, as illustrated in FIG. 15, the third discharge port 5c of the inner tube 5B is positioned at the position of the injection port 3a covered with the porous coating material 10, and is located between the expanded packer 6b. The ground improvement chemical | medical solution G is supplied from the discharge outlet 5c, and is inject | poured into the ground through the injection inlet 3a.

  Also in this embodiment, the same effect as the previous embodiment can be obtained, so even if the injection pressure is increased, the ground improvement chemical solution G is applied to the ground only in a specific area where the ground is relatively weak. It is possible to inject the ground improvement chemical solution G stably over a wide area of the ground without intrusion so as to tear. Then, as illustrated in FIG. 16, the ground on which the structure 13 is erected can be an improved ground strengthened by the ground improving chemical solution G.

  Also in this embodiment, the instantaneous solidifying liquid C and the ground improvement chemical | medical solution G can also be supplied with the same one inner pipe | tube 5C. In the present invention, the number of installation locations of the outer tube packer 11 and the porous coating material 11 provided on the outer tube 3 is not particularly limited.

  In the present invention, the outer tube packer 11 is expanded so as to have a gap with the inner peripheral surface of the insertion hole S, as in the above-described embodiment, by filling the inside with the instantaneous solidifying liquid C. It can also be made. In this case, as illustrated in FIG. 17, injection ports 3 b and 3 c are provided on the surface of the outer tube 3 at a position where the two inflatable outer tube packers 11 are provided. In other words, the expandable outer tube packer 11 is disposed at each position where the injection ports 3b and 3c are formed. Then, the instantaneous solidifying liquid C is filled inside the two outer tube packers 11 through the inlets 3b and 3c to be expanded.

  Specifically, the injection ports 3b and 3c are arranged in the front and rear of the tube axis direction with the injection port 3a for injecting the instantaneous solidifying liquid C into the ground, and a check valve 12 is provided in the injection port 3a. The check valve 12 is formed, for example, by winding a belt-like body made of an elastic body such as rubber around the surface of the outer tube 3 so as to cover the injection port 3a. The check valve 12 abuts two belt-like bodies at a position on the injection port 3a.

  When the outer tube packer 11 is expanded, two inner tubes 5A inserted into the outer tube 3 can be expanded within a range in which the outer tube packers 11 and 11 are provided as illustrated in FIG. Positioning is performed so that the first discharge port 5a and the second discharge port 5b are aligned with each other so that the ranges between the packers 6a overlap. After positioning, each packer 6a is expanded and brought into pressure contact with the inner peripheral surface of the outer tube 3, and the C1 liquid is supplied from the first discharge port 5a and the C2 liquid is supplied from the second discharge port 5b. .

  As a result, the instantaneous solidifying liquid C in which the C1 liquid and the C2 liquid are mixed enters the outer tube packer 11 through the inlets 3b and 3c. By filling the inside of the outer tube packer 11 with the entered instantaneous solidifying liquid C, the outer tube packer 11 is in an expanded state with a predetermined gap with the inner peripheral surface of the insertion hole S. .

  At the same time, as illustrated in FIG. 19, the instantaneous solidification liquid C supplied through the inner pipe 5A is extruded through the injection port 3a so as to leak from the butt surface of the check valve 12 and injected into the ground. . Since the injection port 3 a for injecting the instantaneous solidifying liquid C is sandwiched between the two expanded outer tube packers 11, the instantaneous solidifying liquid C is guided between the two outer tube packers 11. To penetrate the ground.

  In addition, since a predetermined gap (for example, 1.0 cm or less) is provided between each outer tube packer 11 and the inner peripheral surface of the insertion hole S, the strength of the inner peripheral surface of the insertion hole S is low ( Even in the case of weak ground) or the like, the inner peripheral surface of the insertion hole S is not broken by the expanding outer tube packer 11. And the instantaneous setting solidified liquid C can also go outside the outer tube | pipe packer 11 through this gap, and the instantaneous setting solidified liquid C can be osmose | permeated to the wider range of the ground.

  Therefore, the instantaneous setting solidified liquid C surely penetrates the ground and rapidly solidifies to form a strong packer P around the inlet 3a. Thereby, the gap between the inner peripheral surface of the insertion hole S and the outer peripheral surface of the outer tube 3 can be reliably sealed by the packer P formed of the instantaneous setting solidified liquid C.

  Here, before the instantaneous solidifying liquid C is supplied to the ground from the injection port 3a, the outer tube packer 11 is more reliably filled with the instantaneous solidifying liquid C and expanded, than through the supply port 3a. In this structure, the instantaneous solidifying liquid C can be easily supplied to the outside through the supply ports 3b and 3c. Therefore, for example, the area of the supply port 3a that supplies the instantaneous solidifying liquid C to the ground (in the case of a plurality of supply ports 3a, the total area obtained by adding them) is the instantaneous solidifying liquid C in the outer tube packer 11. Is smaller than the area of each of the supply ports 3b, 3c (in the case of a plurality of supply ports 3b, 3c, the total area of them). Or, the rigidity of the check valve 12 is increased to make it more difficult to be elastically deformed. Alternatively, the area of each of the supply ports 3b and 3c is made larger than the area of the supply port 3a, and the rigidity of the check valve 12 is increased to make it more difficult to be elastically deformed. A structure in which the quick setting solidified liquid C can be easily supplied to the outside.

  In addition, since the reverse support valve 12 can adjust the expansion | swelling condition of the outer tube | pipe packer 11 by changing the specification (rigidity etc.), as above-mentioned, it can be functioned as a clearance adjustment means.

  Further, of the supply ports 3b and 3c, the supply port 3c on the distal end side of the outer tube 3 located far from the supply source of the instantaneous solidifying liquid C is less likely to supply the instantaneous solidifying liquid C to the outside. . When the outer tube 3 extends vertically, the lower supply port 3c located far from the supply source of the instantaneous solidifying liquid C has a quick setting property compared to the supply port 3b on the upper side. It becomes difficult to supply the solidified liquid C to the outside.

  Therefore, for example, the area of the supply port 3c (in the case of a plurality of supply ports 3c, the total area obtained by adding them) is the area of the supply port 3b (in the case of the plurality of supply ports 3b, the total area obtained by adding them up). Also make it bigger.

  When the outer tube packer 11 is inflated with the instantaneous setting solidified liquid C as described above, it is not necessary to provide a special pipe for circulating the fluid for expanding the outer tube packer 11. The method and structure for expanding the outer tube packer 11 with the quick setting solidified liquid C can also be used in the embodiment in which the quick setting solidified liquid C and the ground improvement chemical solution G are supplied by the same inner pipe 5C described above. it can.

  The supply speed (that is, the discharge speed) and the gelation time (the time required for solidification) of the quick setting solidification liquid C and the ground improvement chemical liquid G are appropriately set depending on conditions such as the geology of the ground at the construction site. For example, when attention is paid to the gelation time tc of the instantaneous setting solidified liquid C and the time (filling time t) for filling the instantaneous setting solidified liquid C having a correlation with the supply speed of the instantaneous setting solidifying liquid C, It becomes like this. The solidification of the instantaneous solidification liquid C starts immediately after it stops flowing.

When filling the outer tube packer 11 with the instantaneous solidifying liquid C, the outer tube packer 11 starts to expand and the instantaneous solidifying liquid C is injected into the ground from the butting surface of the check valve 12 through the injection port 3a. Start to be. When the filling time t is equal to or longer than the gelation time tc, the instantaneous solidifying liquid C is solidified inside the outer tube packer 11, so that the outer tube packer 11 is maintained in an expanded state.
And between the outer peripheral surface of the outer tube 3 and the inner peripheral surface of the insertion hole S, the outer tube packer 11 maintaining this expanded state, and the instantaneous solidification solidified supplied to the periphery of the expanded outer tube packer 11. The packer P is formed by the liquid C and the instantaneous solidifying liquid C injected into the ground.

  On the other hand, when the filling time t is shorter than the gelation time tc, the instantaneous solidifying liquid C inside the outer tube packer 11 is not solidified, and therefore the outer tube packer 11 in which the instantaneous solidifying liquid C has expanded. After being injected into the periphery and the ground, the outer tube packer 11 contracts. Between the outer peripheral surface of the outer tube 3 and the inner peripheral surface of the insertion hole S, the instantaneous solidifying liquid C supplied to the periphery of the outer tube packer 11 and the instantaneous solidifying liquid C injected into the ground. As a result, the packer P is formed.

  Thus, regardless of the magnitude relationship between the gelation time tc and the filling time t, the packer P can be reliably formed by the instantaneous setting solidified liquid C.

It is explanatory drawing which illustrates the state which inserted the inner pipe | tube which supplies a quick setting solidified liquid to an outer pipe | tube, when inject | pouring a ground improvement chemical | medical solution using the injection apparatus of the ground improvement chemical | medical solution of this invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is explanatory drawing which illustrates the state which the outer tube | patter packer expanded. It is explanatory drawing which illustrates the state which is inject | pouring the instantaneous setting solidification liquid into the ground. It is explanatory drawing which illustrates the state which inserted the inner tube | pipe which supplies a ground improvement chemical | medical solution to an outer tube | pipe. It is B1-B1 sectional drawing of FIG. It is explanatory drawing which illustrates the state which is inject | pouring the ground improvement chemical | medical solution into the ground. It is explanatory drawing which illustrates the formed improved ground. It is sectional drawing which illustrates the inner pipe | tube provided with the switching means. It is explanatory drawing which illustrates the state which extends the casing rod in the horizontal direction and forms the insertion hole. It is explanatory drawing which illustrates the state which has inserted the outer tube | pipe into the casing rod. It is explanatory drawing which illustrates the state which pulled out the casing rod, after expanding the anchor provided in the front-end | tip of an outer tube. It is explanatory drawing which illustrates the state which is inject | pouring the instantaneous setting solidification liquid into the ground. It is explanatory drawing which illustrates the state which is inject | pouring the ground improvement chemical | medical solution into the ground. It is explanatory drawing which illustrates the formed improved ground. It is explanatory drawing which shows another example of an outer tube | pipe. It is explanatory drawing which illustrates the state which supplies the instantaneous setting solidification liquid from the inner tube inserted in the outer tube of FIG. 17, and is expanding the outer tube | pipe packer. It is explanatory drawing which illustrates the state which is inject | pouring the instantaneous setting solidification liquid into the ground.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drilling machine 2 Casing rod 3 Outer tube 3a, 3b, 3c Inlet 4 Anchor 5A, 5B, 5C Inner tube 5a 1st discharge port 5b 2nd discharge port 5c 3rd discharge port 6a, 6b Expandable / shrinkable packer 7a 1st solidified liquid flow path 7b 2nd solidified liquid flow path 7c Chemical liquid flow path 8a, 8b Packer expansion pipe 9 Switching means 10 Porous coating material 11 Outer tube packer 12 Check valve 13 Structure S Insertion hole G Ground improvement chemical liquid P Packer C Instantaneous solidifying liquid

Claims (9)

  Insert an outer tube with a plurality of injection holes provided in the peripheral wall into the insertion hole drilled in the ground, and then insert the inner tube into the outer tube to a predetermined position. Two inflatable packers spaced apart in the axial direction are inflated and pressed against the inner peripheral surface of the outer tube, and the inner wall of the inner tube located between the two inflated packers A ground improvement chemical solution is supplied from a discharge port provided in the ground and injected into the ground from an injection port of the outer tube, and the axial direction is sandwiched by at least one injection port on the surface of the outer tube Two inflatable outer tube packers are provided apart from each other, and the inlet at a position different from the position where the outer tube packer is provided is covered with a porous coating material, and the contracted outer tube packer Inflated to have a gap with the inner peripheral surface of the insertion hole. The solidified liquid is injected into the ground from the inlet located between the outer tube packers to form a packer made of the instantaneous solidified liquid around the inlet, and then covered with the porous coating material. The ground improvement chemical solution is injected into the ground from the ground inlet.   An inner tube different from the inner tube is inserted into the outer tube, and two inflatable packers that are spaced apart in the axial direction on the surface of the other inner tube are inflated to the inner peripheral surface of the outer tube. In a state of pressure contact, an instantaneous setting solidified liquid is supplied from a discharge port provided on the peripheral wall of the inner tube located between the two expanded packers, and between the expanded outer tube packers. Injecting into the ground from the injection port located, forming the packer made of the instantaneous solidifying liquid, and then pulling out the inner pipe and inserting the inner pipe for supplying the ground improvement chemical into the outer pipe. The ground improvement chemical | medical solution injection method of description.   Two expandable and contractible packers provided on the surface of the inner tube in the axial direction are inflated so as to be in pressure contact with the inner peripheral surface of the outer tube, and between the two inflated packers. The instantaneous solidifying liquid is supplied from the discharge port provided on the peripheral wall of the inner pipe located, and is injected into the ground from the inlet located between the expanded outer pipe packers, and consists of the instantaneous solidifying liquid. The method for injecting a ground improvement chemical solution according to claim 1, wherein after the packer is formed, the ground improvement chemical solution is supplied through the inner tube.   When the instantaneous solidifying liquid is supplied from the discharge port provided on the peripheral wall of the inner pipe located between the two expanded packers, the supplied instantaneous solidifying liquid is put into the outer pipe packer. By filling, the outer tube packer is expanded so as to have a gap with the inner peripheral surface of the insertion hole, and the instantaneous solidification liquid is injected into the ground from the injection port located between the expanded outer tube packer. The method for injecting a ground improvement chemical solution according to claim 2 or 3.   The injection method of the ground improvement chemical | medical solution in any one of Claims 1-4 which changed the direction in the middle and formed the said insertion hole in the horizontal direction.   An outer tube to be inserted into an insertion hole cut in the ground, an inner tube to be inserted into the outer tube and moveable in the axial direction, and an inner tube to supply an instantaneous solidifying solution. A plurality of inlets communicating with the inner side and the outer side of the tube in the peripheral wall of the outer tube are formed apart from each other in the axial direction, and two inflatable outer tube packers are provided on the surface of the outer tube in the axial direction, At least one inlet is disposed between the two outer tube packers, and an inlet at a position different from the position where the outer tube packer is provided is covered with a porous coating material. Two inflatable / shrinkable packers that are provided with a gap adjusting means for adjusting the gap between the inner peripheral surface of the insertion hole when each is expanded, and are spaced apart in the axial direction on the surface of each inner tube Between the two packable packers An injection device ground improvement chemical placing the discharge opening in the peripheral wall of the inner tube.   An outer tube to be inserted into an insertion hole cut in the ground, and an inner tube that is inserted into the outer tube and movable in the axial direction, and an inlet that communicates the inner side and the outer side of the tube with a peripheral wall of the outer tube. A plurality of axially spaced outer tube packers are formed on the surface of the outer tube, and two expandable outer tube packers are provided on the surface of the outer tube, and at least one inlet is disposed between the two outer tube packers. In addition, the inlet at a position different from the position where the outer tube packer is provided is covered with a porous coating material, and when each of the two outer tube packers is expanded, it is between the inner peripheral surface of the insertion hole. A gap adjusting means for adjusting to have a gap is provided, and two inflatable / expandable packers spaced in the axial direction are provided on the surface of the inner tube, and a discharge port is provided on a peripheral wall between the two inflatable / defensible packers. And place ground improvement chemical and instantaneous setting solidified liquid in this inner tube. Recombinant and injection device ground improvement chemical provided with switching means for supplying.   On the surface of the outer tube at the position where the two expandable outer tube packers are provided, there is provided an inlet that communicates the inner side of the tube with the outer side of the tube. 8. The ground improvement chemical solution injection device according to claim 6 or 7, wherein the tube packer is filled and expanded.   9. The ground improvement chemical solution injection device according to claim 6, wherein the outer tube and the inner tube have flexibility.

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