JP5210921B2 - Method of injecting ground improvement chemical - Google Patents

Description

  The present invention relates to a method for injecting a ground improvement chemical solution, and more specifically, after filling a drilled insertion hole with a slow-sealing sealing material, and inserting a ground improvement chemical solution into the ground using a double pipe. Suppress the radial deviation of the outer tube with respect to the hole, and make sure that the loose-sealing seal material enters the gap between the inner peripheral surface of the insertion hole and the outer peripheral surface of the outer tube. The present invention relates to a method for injecting a ground improvement chemical solution capable of obtaining a sealing effect.

  In order to strengthen the soft ground, various methods for injecting the ground improvement chemical into the target ground using a double pipe have been proposed (for example, see Patent Document 1). When ground improvement is performed using a double pipe, there is a method in which a drilled insertion hole is filled with a slow-sealing seal material in advance. When the outer tube is inserted into the insertion hole, a loose sealant enters between the inner peripheral surface of the insertion hole and the outer peripheral surface of the outer tube, and when this is solidified, the clearance is sealed. A crack is formed in the solidified loose sealing material by discharging water from an inlet provided in the peripheral wall of the outer tube. Next, the ground improvement chemical solution is supplied through the inner pipe inserted into the outer pipe and injected into the ground from the inlet of the outer pipe. Since the space between the inner peripheral surface of the insertion hole and the outer peripheral surface of the outer tube is sealed by the solidified sealing material, the ground improvement chemical is injected into the ground from the cracks formed without leaking.

  However, when the outer tube length increases and the outer diameter becomes relatively small, or when the insertion hole is inclined with respect to the vertical or extends in the horizontal direction, the outer tube is inserted. When inserted into the hole, the outer tube tends to be biased in the radial direction with respect to the insertion hole. As a result, a sufficient gap between the inner peripheral surface of the insertion hole and the outer peripheral surface of the outer tube cannot be ensured, and the loose sealant does not enter the gap. For this reason, even if the slow-sealing seal material is solidified, an area in which a sufficient seal layer is not formed by the slow-sealing seal material between the inner peripheral surface of the insertion hole and the outer peripheral surface of the outer tube. If there is a region where a sufficient sealing layer is not formed by the slow-sealing seal material, the ground improvement chemical solution leaks through the region, and there is a problem that the improved ground as planned cannot be formed.

JP 2005-314938 A

  An object of the present invention is to suppress the radial deviation of the outer tube with respect to the insertion hole when injecting the ground improvement chemical solution into the ground using the double tube, and the inner peripheral surface of the insertion hole and the outer peripheral surface of the outer tube. It is an object of the present invention to provide a method for injecting a ground improvement chemical solution that allows a slow-sealing sealing material to be surely inserted between the gaps and obtains a sufficient sealing effect by the slow-sealing sealing material.

  In order to achieve the above object, the ground improvement chemical solution injection method of the present invention has a plurality of injection ports provided in the peripheral wall spaced apart in the axial direction after filling an insertion hole drilled in the ground with a sealing agent. Insert the outer tube whose tip is closed into this insertion hole, and then inject the instantaneous solidifying liquid into the expandable spacer provided on the surface of the outer tube before the loose sealing material solidifies. To ensure a clearance between the inner peripheral surface of the insertion hole and the outer peripheral surface of the outer tube, and then discharge water from the injection port to form a crack in the solidified sealing material around the injection port. And then inflating two inflatable packers provided in the axial direction on the surface of the inner tube inserted into the outer tube so as to be in pressure contact with the inner peripheral surface of the outer tube, From the discharge port provided in the peripheral wall of the inner pipe located between these two inflated packers By supplying a good chemical, it is characterized in injecting into the ground from the inlet of the outer tube.

  Here, the spacer is provided on the surface of the outer tube in the outer tube axial direction as a pair, and the pair of spacers are expanded by injecting the instantaneous solidifying liquid into the pair of spacers. It is also possible to inject the instantaneous solidifying liquid into the ground from the injection port located between the spacers. An inner tube different from the inner tube is inserted into the outer tube, and two inflatable packers provided on the surface of the inner tube so as to be spaced apart from each other in the axial direction are inflated and pressed against the inner peripheral surface of the outer tube. In this state, the instantaneous solidifying liquid is supplied from the discharge port provided on the peripheral wall of the inner tube located between the two inflated packers, and is expanded by being injected into the spacer. Then, the inner pipe is pulled out from the outer pipe, and the inner pipe for supplying the ground improvement chemical solution can be inserted into the outer pipe. By supplying water through the inner pipe that supplies the ground improvement chemical solution, water is discharged from the injection port to form a crack in the solidified sealing material around the injection port, and then through the inner pipe A ground improvement chemical | medical solution can also be supplied and it can also inject | pour into the ground from the inlet of the said outer tube | pipe. The spacer is an annular body that is continuous in the circumferential direction of the outer tube and expands with the same width toward the outer periphery, and the circumferential wall of the outer tube has a uniform central angle in the circumferential direction with respect to one spacer. It is also possible to arrange three or more spacer inlets having the same diameter and supply the instant solidifying liquid from these spacer inlets to be injected into the spacers. The insertion hole may be inclined with respect to the vertical or extend in the horizontal direction.

  According to the present invention, after the insertion hole drilled in the ground is filled with a slow-sealing sealant, an outer tube with a plurality of inlets provided on the peripheral wall and spaced apart in the axial direction is closed to the insertion hole. Then, before the loose sealing material is solidified, it is inflated by injecting an instantaneous solidifying liquid into an expandable spacer provided on the surface of the outer tube, and the inner periphery of the insertion hole Since the clearance between the surface and the outer peripheral surface of the outer tube is ensured, the radial deviation of the outer tube with respect to the insertion hole can be corrected. As a result, the slow-sealing sealing material can surely enter between the inner peripheral surface of the insertion hole and the outer peripheral surface of the outer tube, and a seal layer is formed by the slow-sealing sealing material solidified in the clearance. be able to.

  Next, water is discharged from the injection port to form a crack in the solidified sealing material around the injection port, and then two swellings provided on the surface of the inner tube inserted into the outer tube are separated from each other in the axial direction. The shrinkable packer is inflated and brought into pressure contact with the inner peripheral surface of the outer tube, and the ground improvement chemical solution is supplied from the discharge port provided on the peripheral wall of the inner tube located between the two expanded packers. Then, when injected into the ground from the inlet of the outer tube, the ground improvement chemical solution is solidified without leaking between the inner peripheral surface of the insertion hole and the outer peripheral surface of the outer tube. It is injected into the ground through the cracks formed. As described above, a sufficient sealing effect by the solidified slow-sealing sealing material can be obtained, and the ground improvement chemical can be stably injected into the ground.

It is a longitudinal cross-sectional view which illustrates the state which has inserted the outer tube | pipe into the insertion hole filled with the loose sealing material. It is a longitudinal cross-sectional view which illustrates the outer tube | pipe installed in the insertion hole. It is explanatory drawing which illustrates the inside of the outer pipe | tube which has inserted the inner pipe | tube which supplies a quick setting solidification liquid to the predetermined position. It is AA sectional drawing of FIG. It is explanatory drawing which illustrates the inside of the outer tube | pipe at the time of expanding the spacer. It is BB sectional drawing of FIG. It is explanatory drawing which illustrates the inside of the outer tube | pipe at the time of expanding another spacer. It is explanatory drawing which illustrates the inside of the outer tube | pipe at the time of cracking the solidified slow-release sealing material. It is CC sectional drawing of FIG. It is explanatory drawing which illustrates the inside of the outer tube | pipe at the time of inject | pouring a ground improvement chemical | medical solution to the ground. It is explanatory drawing which illustrates the formed improved ground. It is a cross-sectional view which illustrates the outer pipe | tube which has inserted 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 is expanding the spacer of the outer tube inserted in the insertion hole extended in the horizontal direction.

  Hereinafter, a method for injecting a ground improvement chemical solution of the present invention will be described based on embodiments.

  In the present invention, an outer tube 3 inserted into the insertion hole S as illustrated in FIG. 1, an inner tube 5A inserted into the outer tube 3 and movable in the outer tube axis direction as illustrated in FIG. 3, As illustrated in FIG. 8, an inner tube 5B that is inserted into the outer tube 3 and is movable in the outer tube axial direction is used. Instantaneous solidifying liquid C is supplied through one inner pipe 5A, and water W and ground improvement chemical liquid G are supplied through the other inner pipe 5B. In addition, the instantaneous setting solidification liquid C, the water W, and the ground improvement chemical | medical solution G can also be supplied using a separate inner pipe, respectively, and can also be supplied using the same inner pipe, respectively.

  As illustrated in FIG. 1, the ground is drilled to form an insertion hole S extending in the vertical direction, and the insertion hole S is filled with a slow-sealing seal material L. The slow-setting sealing material L is, for example, a sealing material that solidifies in about one day, and examples thereof include cement bentonite and a slow-binding chemical solution.

  The loose sealant L is filled up to the vicinity of the upper end of the insertion hole S, and the outer tube 3 is inserted into the insertion hole S. As illustrated in FIG. 2, the outer tube 3 is installed in the insertion hole S with the tip of the outer tube 3 in contact with the bottom of the insertion hole S.

  The outer tube 3 is formed of various resins or the like, and for example, an outer tube 3 made of vinyl chloride is used. The outer tube 3 has, for example, an outer diameter of about 0.3 m to 0.5 m, a length of about 10 m to 30 m, and a peripheral wall thickness of about 1.0 mm to 3.0 mm. The outer tube 3 is a cylindrical body having a closed front end and an open rear end, and a plurality of injection ports 3a communicating the inner side of the tube with the outer side of the tube are formed in the peripheral wall so as to be spaced apart in the outer tube axis direction. .

  A plurality of expandable spacers 4 are provided on the surface of the outer tube 3 so as to be spaced apart from each other in the outer tube axis direction. A spacer inlet 3b is formed in the peripheral wall of the outer tube 3 at the position where the spacer 4 is installed. That is, the spacer 4 is provided so as to cover the spacer inlet 3b. The sizes of the inlet 3a and the spacer inlet 3b are, for example, about 3 mm to 10 mm in diameter.

  The spacer 4 is a hollow annular body that is continuous in the circumferential direction of the outer tube 3 and expands toward the outer periphery with the same width, and is formed of an elastic material such as rubber. A plurality of spacers 4 are arranged at appropriate intervals in the outer tube axis direction.

  In this embodiment, a pair of spacers 4, 4 spaced apart in the outer tube axis direction with the injection port 3 a interposed therebetween are provided at a plurality of locations with appropriate intervals in the outer tube axis direction. Instead of the pair of spacers 4, 4, it is possible to simply provide one spacer 4 at each installation location.

  By inserting the outer tube 3 into the insertion hole S, the loose sealant L overflows from the upper end opening of the insertion hole S. The loose sealant L that has not overflowed remains in the gap between the inner peripheral surface of the insertion hole S and the outer peripheral surface of the outer tube 3.

  Next, as illustrated in FIG. 3, the inner tube 5A is inserted into the outer tube 3, and then the instantaneous solidifying liquid C supplied through the inner tube 5A is injected into the contracting spacer 4 so as to be loosely set. The spacer 4 is expanded before the sealing material L is solidified. The instantaneous solidification liquid C is a two-liquid type in which the C1 liquid and the C2 liquid are mixed and rapidly solidified, and examples thereof include water glass grout and plastic grout. The solidification time of the quick setting solidified liquid C is about 5 seconds to 30 seconds.

  The inner tube 5A has two inflatable / expandable packers 6a spaced on the surface in the inner tube axis direction, and the C1 solution of the instantaneous solidification liquid C is applied to the peripheral wall between the two inflatable / defensible packers 6a. A first discharge port 5a for supplying and a second discharge port 5b for supplying the C2 liquid are arranged. The inside of the inner tube 5A is divided into two as illustrated in FIG. 4, 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 that can be expanded and contracted, such as rubber, and is expanded by a fluid flowing in through the packer expansion pipe 8a and contracted by the outflow of the fluid.

  When the spacer 4 is expanded, as illustrated in FIG. 5, the range between the two expandable packers 6 a of the inner tube 5 </ b> A inserted in the outer tube 3 is within the range where the spacer 4 is provided. The first discharge port 5a and the second discharge port 5b are positioned so as to overlap each other. 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 as illustrated in FIGS. C2 liquid is supplied from the 2nd discharge outlet 5b.

  As a result, the instantaneous solidification liquid C in which the C1 liquid and the C2 liquid are mixed is injected into the spacer 4 through the spacer injection port 3b. The spacer 4 is expanded by filling the spacer 4 with the injected instantaneous solidifying liquid C. The expanded spacer 4 becomes an inclusion, and a gap is secured between the inner peripheral surface of the insertion hole S and the outer peripheral surface of the outer tube 3. A loose sealant L is interposed between the expanded spacer 4 and the inner peripheral surface of the insertion hole S.

  In order to ensure a uniform gap in the radial direction between the inner peripheral surface of the insertion hole S and the outer peripheral surface of the outer tube 3, the spacer 4 is continuous in the circumferential direction of the outer tube 3 and directed toward the outer periphery. It is preferable that the annular body expands with the same width. Further, it is preferable that three or more spacer inlets 3b having the same diameter are arranged on the peripheral wall of the outer tube 3 with respect to the one spacer 4 at an equal central angle in the circumferential direction. In this embodiment, four spacer inlets 3 b having the same diameter are arranged on the peripheral wall of the outer tube 3 with respect to one spacer 4 at an equal central angle (90 °) in the circumferential direction.

  When the first discharge port 5a and the second discharge port 5b formed so that the discharge destinations are close as illustrated in FIG. 4 are mixed so that the C1 liquid and the C2 liquid collide, It becomes easy to mix uniformly. As illustrated in FIG. 7, each spacer 4 is expanded by the same procedure. When the inner tube 5A is moved in the vertical direction, the packer 6a is contracted.

  As the instantaneous solidifying liquid C filled in the spacer 4 is solidified, the expanded state of the spacer 4 is maintained. Thereby, when the outer tube 3 is installed in the insertion hole S, even if there is a radial deviation of the outer tube 3 with respect to the insertion hole S, the deviation is corrected and the inner peripheral surface of the insertion hole S is corrected. And a sufficient clearance can be secured between the outer pipe 3 and the outer peripheral surface of the outer tube 3. The loose sealant L enters the gap.

  As illustrated in FIG. 5, as the spacer 4 expands, the instantaneous solidifying liquid C supplied through the inner tube 5 </ b> A is injected into the ground through the inlet 3 a between the pair of spacers 4, 4. Since the injection port 3a for injecting the instantaneous solidifying liquid C into the ground is sandwiched between the two inflated spacers 4, the instantaneous solidifying liquid C is in the expanded spacer 4 and the insertion hole S. Although it may enter between the inner peripheral surface, it is difficult to leak in the vertical direction through the gap between the inner peripheral surface of the insertion hole S and the outer peripheral surface of the outer tube 3. Therefore, the instantaneous setting solidified liquid C surely penetrates the ground and rapidly solidifies, and a strong packer P is formed 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 is sealed by the packer P formed by the instantaneous setting solidified liquid C.

  Here, before the instantaneous solidifying liquid C is supplied from the inlet 3a to the ground, in order to surely fill the spacer 4 with the instantaneous solidifying liquid C and expand it, rather than through the inlet 3a, It is preferable to have a structure in which the quick-setting solidified liquid C can be easily supplied to the outside through the spacer inlet 3b. For example, a check valve that allows the instantaneous solidifying liquid C to flow only from the inside to the outside of the outer tube 3 is provided in the inlet 3a, so that the flow path resistance of the inlet 3a is larger than that of the spacer inlet 3b. To do.

  Alternatively, the area of the inlet 3a (in the case of a plurality of inlets 3a, the total area obtained by adding them) is combined with the area of the spacer inlet 3b (in the case of a plurality of inlets 3b, respectively). Less than the total area). When a check valve is provided at the inlet 3a and the spacer inlet 3b, the check valve provided at the inlet 3a is less likely to be elastically deformed as compared to the check valve provided at the spacer inlet 3b. .

  Next, water W is discharged from the inlet 3a of the outer tube 3 to crack the solidified loose sealing material L around the inlet 3a to form a crack. When water W is discharged from the inlet 3a, the inner tube 5A is pulled out from the outer tube 3, and then another inner tube 5B is inserted into the outer tube 3 as illustrated in FIG.

  The inner tube 5B is a cylindrical body whose front end is closed, and has two inflatable and retractable packers 6b spaced from each other in the inner tube axis direction on the surface thereof. A third discharge port 5c is disposed on the peripheral wall between the two inflatable / shrinkable packers 6b.

  The inside of the inner pipe 5B is a flow path 7c through which water W and a ground improvement chemical solution G to be described later circulate as illustrated in FIG. 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 is expanded by the fluid flowing in through the packer expansion pipe 8b and contracted by the outflow of the fluid.

  After the inner tube 5B is inserted to a predetermined position of the outer tube 3, the contracted packer 6b is inflated and brought into pressure contact with the inner peripheral surface of the outer tube 3. In this state, water W is supplied from the third discharge port 5c. Since the third discharge port 5c is sandwiched between the two expanded packers 6b, the water W may leak up and down through the gap between the inner peripheral surface of the outer tube 3 and the outer peripheral surface of the inner tube 5B. Absent.

  Since the supplied water W is discharged through the injection port 3a, the solidified loose sealing material L around the injection port 3a is cracked by this water pressure to form a crack. This cracking operation is performed for each inlet 3a. When moving the inner tube 5B in the vertical direction, the packer 6b is contracted.

  Next, the ground improvement chemical solution G is supplied in place of the water W through the inner tube 5 </ b> B inserted into the outer tube 3. 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.

  As illustrated in FIG. 10, after the inner tube 5 </ b> B is inserted to a predetermined position of the outer tube 3, the contracted packer 6 b is expanded and brought into a pressure contact state with the inner peripheral surface of the outer tube 3. In this state, 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 solution G leaks up and down through the gap between the inner peripheral surface of the outer tube 3 and the outer peripheral surface of the inner tube 5B. There is nothing. The inside of the outer tube 3 when the ground improvement chemical solution G is injected into the ground is as illustrated in FIG.

  The supplied ground improvement chemical | medical solution G is discharged through the injection port 3a. Here, since the crack is formed in the solidified sealing material L around the injection port 3a, the ground improvement chemical solution G is injected into the ground through the crack. The operation of injecting the ground improvement chemical solution G is performed on each of the injection ports 3a. When moving the inner tube 5B in the vertical direction, the packer 6b is contracted.

  Since the outer tube 3 is installed by the expanded spacer 4 so that the radial deviation with respect to the insertion hole S is suppressed, there is no gap between the inner peripheral surface of the insertion hole S and the outer peripheral surface of the outer tube 3. The sealing material is surely entered and the sealing layer is formed of the solidified sealing material L that has solidified. Therefore, the ground improvement chemical solution G is injected into the ground through a crack formed in the solidified loose sealant L without leaking up and down through the space between the inner peripheral surface of the insertion hole S and the outer peripheral surface of the outer tube 3. Is done.

  Therefore, even when using a long and easily deformable outer tube 3 with a small outer diameter, a sufficient sealing effect is obtained by the solidified sealing material L, and the ground improvement chemical is stably injected into the ground. Can be made. Thereby, the improved ground as planned can be formed as illustrated in FIG.

  Even if the ground improvement chemical solution G leaks up and down through the space between the inner peripheral surface of the insertion hole S and the outer peripheral surface of the outer tube 3, the packer formed by the expanded spacer 4 or the instantaneous solidification liquid C P prevents further leakage.

  The instantaneous setting solidified liquid C, the water W, and the ground improvement chemical | medical solution G can be supplied by using one inner pipe | tube 5C of the structure illustrated in FIG. This inner pipe 5C is provided with a switching means 9 for switching and supplying the instantaneous solidifying liquid C (C1 liquid, C2 liquid), water W and ground improvement chemical liquid G to the inner pipe 5A shown in FIG. It is. 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 pipe 5C is used, until the spacer 4 is expanded 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 cracking the solidified slow-release sealing material L, the setting of the switching means 9 is switched to supply water W 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 flow path 7c, and the inner tube 5C is moved in the outer tube axial direction to be positioned at a predetermined position. And the 1st discharge port 5a and the 2nd discharge port 5b are functioned as the 3rd discharge port 5c, the water W is supplied, and the water W is discharged from the injection port 3a.

  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 inner pipe 5C is moved in the outer pipe axial direction to be positioned at a predetermined position, and the first discharge port 5a and the second discharge port 5b are functioned as the third discharge port 5c to supply the ground improvement chemical solution G. The ground improvement chemical | medical solution G is inject | poured into the ground from the inlet 3a.

  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. In this case, as illustrated in FIG. 13, the casing rod 2 is obliquely extended from the drilling machine 1 to drill the ground, and the drilling direction is changed to a horizontal position in the middle to insert the hole into the ground below the structure 10. S is formed.

  Next, as illustrated in FIG. 14, the outer tube 3 is inserted into the insertion hole S filled with the slow-binding sealing material L. And the spacer 4 is expanded by the instantaneous setting solidified liquid C supplied through the inner pipe | tube 5A inserted in the outer pipe | tube 3 similarly to the said embodiment. Thereafter, as in the above embodiment, the improved ground is formed by performing a cracking operation of the solidified sealing material L that has been solidified and an injection operation of the ground improvement chemical solution G.

  If the insertion hole S is inclined with respect to the vertical or extends in the horizontal direction, the radial deviation of the outer tube 3 with respect to the insertion hole S increases, and the inner peripheral surface of the insertion hole S and the outer tube A sufficient gap cannot be secured between the outer peripheral surface 3 and the outer peripheral surface 3.

  However, in the present invention, the radial displacement of the outer tube 3 with respect to the insertion hole S is corrected by the expanded spacer 4, so that there is sufficient space between the inner peripheral surface of the insertion hole S and the outer peripheral surface of the outer tube 3. It becomes possible to secure a gap. Therefore, the slow-sealing sealing material L surely enters the gap, and a sufficient sealing effect by the solidified slow-sealing sealing material L can be obtained.

DESCRIPTION OF SYMBOLS 1 Hole cutter 2 Casing rod 3 Outer tube 3a Inlet 3b Spacer inlet 4 Spacer 5A, 5B, 5C Inner tube 5a 1st discharge port 5b 2nd discharge port 5c 3rd discharge port 6a, 6b Expandable / shrinkable packer 7a 1st solidification liquid flow path 7b 2nd solidification liquid flow path 7c flow path 8a, 8b Packer expansion pipe 9 Switching means 10 Structure C Instantaneous solidification liquid G Ground improvement chemical liquid L Slow sealant P Packer S Insertion Hole

Claims (6)

  After filling the insertion hole drilled in the ground with a loosely-sealing sealant, an outer tube with a plurality of injection ports provided on the peripheral wall and closed at the tip is inserted into the insertion hole, and then inserted into the insertion hole. Before the loose sealant is solidified, it is expanded by injecting an instantaneous solidifying liquid into an expandable spacer provided on the surface of the outer tube, and the inner peripheral surface of the insertion hole and the outer periphery of the outer tube Securing a gap with the surface, then discharging water from the inlet to form a crack in the solidified sealing material solidified around the inlet, and then on the surface of the inner pipe inserted into the outer pipe 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 the injection port of the outer pipe. Injection method of improving the chemical.   A pair of the spacers are provided on the surface of the outer tube so as to be spaced apart from each other in the axial direction of the outer tube. The spacer is expanded by injecting the instantaneous solidifying liquid into the pair of spacers, and between the pair of spacers. The ground improvement chemical | medical solution injection method of Claim 1 which inject | pours a quick setting solidification liquid into the ground from the said injection hole located in a ground.   An inner tube different from the inner tube is inserted into the outer tube, and two inflatable packers provided on the surface of the inner tube so as to be spaced apart from each other in the axial direction are inflated and pressed against the inner peripheral surface of the outer tube. In this state, the instantaneous solidifying liquid is supplied from the discharge port provided on the peripheral wall of the inner tube located between the two inflated packers, and is expanded by being injected into the spacer. 3. The method for injecting a ground improvement chemical solution according to claim 1, wherein the inner tube is pulled out from the outer tube and the inner tube for supplying the ground improvement chemical solution is inserted into the outer tube.   By supplying water through the inner pipe that supplies the ground improvement chemical solution, water is discharged from the injection port to form a crack in the solidified sealing material around the injection port, and then through the inner pipe The ground improvement chemical | medical solution injection method in any one of Claims 1-3 which supply a ground improvement chemical | medical solution and inject | pour into a ground from the injection hole of the said outer tube | pipe.   The spacer is an annular body that is continuous in the circumferential direction of the outer tube and expands with the same width toward the outer periphery, and the circumferential wall of the outer tube has a uniform central angle in the circumferential direction with respect to one spacer. The ground improvement according to any one of claims 1 to 4, wherein three or more spacer inlets having the same diameter are arranged, and the instantaneous solidifying liquid is supplied from the spacer inlets and injected into the spacers. How to inject chemicals.   The method for injecting a ground improvement chemical according to any one of claims 1 to 5, wherein the insertion hole is inclined with respect to the vertical or extends in the horizontal direction.

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