JP2016156142A - Ground injection method and ground injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ground injection method and a ground injection device, which can evenly infiltrate and inject an injection material in the ground around a porous wall at low pressure and in a wide range.SOLUTION: An injection pipe 1 is installed in a borehole 2 and an injection material is infiltrated and injected in the ground around a porous wall. The injection pipe 1 comprises: an injection pipe body 4 which has multiple injection material discharge ports 4a in a pipe axial direction; and a long rubber slit tube 5 which tightly adheres to an outer circumference of the injection pipe body 4 and has multiple injection material injection slits 5a at positions that do not overlap with the injection material discharge ports 4a. The injection material fed to the injection pipe body 4 is infiltrated and injected in the ground around the porous wall by: pressing and widening the long rubber slit tube 5 by discharge pressure from the multiple injection material discharge ports 4a; being discharged between the long rubber slit tube 5 and the injection pipe body 4; flowing in a pipe axial direction and a circumferential direction between the long rubber slit tube 5 and the injection pipe body 4; and being injected at a fluid pressure, which overcomes an elastic force of the long rubber slit tube 5, from the multiple injection material injection slits 5a to the outside of the long rubber slit tube 5.SELECTED DRAWING: Figure 1

Description

  The present invention is to improve the water-stopping property of the ground, increase the strength, prevent liquefaction, etc. by embedding an injection pipe in the drilling hole formed in the ground and injecting the injection material into the ground around the hole wall The present invention relates to a ground injection device and a ground injection method for carrying out the improvement. Conventionally, there is a known method for injecting an injection solution from the tip of an injection tube having a plurality of small holes while moving the injection stage upward after drilling with an injection tube with a metal crown. Unlike the underground type, the injection tube did not have a check function or repeated injection function by re-injection, so it could not be expected to have a certain effect. In recent years, infusion methods such as liquefaction countermeasures and the like, it has come to be required to penetrate between soil particles in a wide range and to be economically constructed at a high discharge rate. In order to solve these conflicting problems, the present inventor has made it possible to rapidly infiltrate between soil particles evenly with a large discharge amount by means of a columnar infiltration injection method by injection from an injection pipe embedded in soft ground or a multi-point simultaneous injection method. An infiltration injection method (Patent Document 1) was developed. The present invention is a further development of the above-mentioned columnar penetration injection method.

  In the ground injection method, drilling holes are formed in the ground, and ground reinforcement such as cement-based or silica-based injection materials, or ground unsaturation such as bubbles and microbubbles are injected through the injection pipe embedded in the hole. This method is used to improve the ground by injecting wood or soil purification material, mainly for the purpose of improving the water-stopping property of the ground, increasing the strength, preventing liquefaction, and filling the cavity or purifying the ground. Is called.

  For example, Patent Document 1 discloses a ground improvement method in which an injection pipe is embedded in a drilling hole formed in the ground, and a cement-based or silica-based injection material is injected into the ground through the injection pipe to solidify and strengthen the ground. It is disclosed.

  The injection tube of the above-mentioned prior application patent is composed of an injection tube body and a columnar penetration source formed on the outer periphery of the injection tube body. Discharge ports are provided at a plurality of locations at intervals in the tube axis direction within a certain range on the outer periphery of the injection tube body, and check valves are attached to the respective discharge ports.

  The columnar penetration source is attached to the outer periphery of the injection tube main body with a sheet material having a certain thickness such as a woven fabric, a nonwoven fabric or a mat so as to cover the plurality of discharge ports on the outer periphery of the injection tube main body and the respective check valves. Alternatively, a columnar permeation source having a thickness around the inlet is formed by coating a water-permeable sheet thereon.

  The injection tube constructed as described above is inserted into the ground drilling hole, and the surrounding void is filled with a seal grout made of low-strength cement slurry or the like. When the injection material is injected into the injection tube body from the ground, the injection material is discharged into the columnar penetration source from each outlet of the injection tube body, and the ground of each stage around the hole wall is crushed from the columnar penetration source. It is injected into the inside. At that time, the injection material discharged from the discharge port into the columnar penetration source spreads throughout the columnar penetration source, and is injected into the ground from the columnar penetration source. And can be infused uniformly.

Japanese Patent No. 4848553

  However, the injection tube described in Patent Document 1 is a columnar shape in which the outer periphery of the injection tube body is covered with a water-permeable material having a certain thickness such as a woven fabric, a nonwoven fabric, or a mat, or further covered with a water-permeable sheet from above. A columnar penetration source consisting of a space is formed, and the injection liquid discharged from the injection tube outlet at the time of injection spreads easily from the columnar penetration source to the entire surface and penetrates into the ground to enable the columnar injection. It is. Therefore, since the outer diameter of the injection tube becomes thick, it is necessary to increase the diameter of the hole for inserting the injection tube, and there is a problem that the cost increases.

  Also, since the outer diameter is large, it is difficult to bend because it is difficult to insert into a borehole drilled into a curved shape, so it is not suitable for ground improvement by inserting it under the ground surface of an existing building. It was.

  In addition, when the suspension is injected, there is a problem that the suspension is clogged in a gap such as a mat and the subsequent solution-type injection solution is difficult to be injected. Also, when columnar penetration is attempted using a solution type grout with good permeability and long gelation time, if the columnar penetration source is long, there is a weak part of the drilling wall or a weak part of the seal grout. There was a tendency that the injection liquid was easy to concentrate and it was difficult to inject into the ground from the full length of the columnar penetration source.

  In addition, a method of using a coating material that coats the outer periphery of the injection outer tube with a polygonal cross-sectional shape such as a quadrilateral for the purpose of columnar penetration, or a coating material that has a vertical groove inside the coating material is also presented. However, both of these methods are troublesome to manufacture in terms of structure and shape and increase the manufacturing cost, and require a certain thickness to form the necessary corners and grooves, or the injection tube The tension of the coating material is not sufficiently applied in the circumferential direction, and the diameter of the injection pipe is increased. Therefore, the diameter of the drilling hole is increased, the effect of the check valve and the function of breaking the solidified body of the seal grout in the vertical direction. There are problems such as insufficient.

  The present invention has been made to solve the above-described problems, and has a simple structure and is easy to manufacture. The injection solution is evenly distributed in the axial direction regardless of the ground outside the injection tube and the sealing condition. After injecting into the ground and injecting into the ground, it penetrates almost parallel to the horizontal direction (laminar flow), and it is possible to infiltrate columnarly and form a columnar consolidated body, and simultaneously to any multiple stages It is possible to repeat injection and suspension injection material, combined injection of suspension and solution, and also to be freely deformable and inserted into curved holes.

  The present invention is an invention that solves the above-mentioned problems, and is provided in a ground injection device that is provided in a drilling hole formed in the ground and has an injection pipe for injecting an injection material into the ground around the hole wall into a columnar penetration. This is an injection method. That is, the present invention provides an injection tube main body having a plurality of injection material discharge ports in the tube axis direction, and is in close contact with the outer periphery of the injection tube main body and in a position not overlapping with the plurality of injection material discharge ports in the tube axis direction of the injection tube. A cylindrical elastic covering (rubber slit tube) having a circular cross section having a plurality of injection material injection slits along the cylindrical elastic covering (rubber slit tube) in a tangential direction of a circular cross section by elastic force The entire length of the tubular body of a predetermined length was in close contact with the outer peripheral surface of the injection tube main body so that the tensile force of the rubber was generated over the entire length, and the injection material discharge port was sealed, and the liquid was fed to the injection tube main body. The injection material overcomes the tensile force by the discharge pressure from the plurality of injection material discharge ports, spreads the cylindrical elastic covering, and discharges it between the cylindrical elastic covering and the injection tube body. , Injection with said cylindrical elastic covering It flows in the tube axis direction and the circumferential direction of the injection tube body between the main body, reaches the plurality of injection material injection slits, and extends outside the cylindrical elastic coating body along the long axis of the injection tube. Simultaneous injection at a discharge pressure that overcomes the elastic elasticity of the rubber acting over the entire length of the body, and seal grout consolidation or cracks generated in the vertical direction in the drilling diameter into the ground around the hole wall It penetrates into a column and penetrates between soil particles at a low pressure after discharging to the ground even with a large discharge amount.

  In addition, when the liquid feeding to the injection tube main body is stopped, the entire surface of the cylindrical elastic cover (rubber slit tube) is brought into close contact with the outer peripheral surface of the injection tube main body by the elastic force, thereby closing the injection material discharge port. The injection material sprayed out of the cylindrical elastic covering is configured not to flow back into the injection tube body.

  In particular, in the injection pipe of the present invention, the covering around the injection pipe is in close contact with the injection pipe over the entire surface of the cylindrical body having a thin cross-sectional shape with a rubber elastic tensile force, and the effect of the check valve is generated on the front surface. The suspension does not clog the mat unlike the above-mentioned columnar penetration source.

  In addition, for the same reason, the check valve works on the entire cylindrical body to prevent the backflow of the injected liquid from the outside due to the elastic force of the cylindrical elastic cover having a circular cross section even after the suspension grout is injected. The suspension grout is reinjected, or after the suspension grout is injected, the solution type grout can also be injected. In particular, even in the case of suspension type injection material as well as suspension type injection material, if the injection is stopped at the stage where a predetermined amount is injected, the remaining injection solution in the elastic coating will be pushed out from the slit due to the rubber elasticity of the elastic coating. A suspension or gel remains between the elastic coating and the injection tube main body, and does not prevent the subsequent reinjection and does not prevent the check effect.

  As described above, the present invention is an invention of a ground injecting apparatus in which an injecting liquid ejected around the hole wall with a large discharge amount is infiltrated and injected into the ground over a wide range even at a low pressure. It is as follows.

  (1). A plurality of injection material discharge ports are provided on the outer periphery of the injection tube body at intervals in the tube axis direction, and a cylindrical elastic covering (rubber slit tube) having a circular cross section is adhered to the outer periphery of the injection tube body. At the same time, a plurality of injection material injection slits are provided in the cylindrical elastic covering having a circular cross section so as not to overlap the injection material discharge port along the injection tube axial direction.

  The cylindrical elastic covering with a circular cross section is a long rubber slit tube or the like, and is in the tube axis direction of the injection tube main body so as to seal a plurality of injection material discharge ports by tightly adhering to the outer periphery of the injection tube main body by rubber elasticity It adheres to the outer periphery of a predetermined length.

  (2) In such a configuration, when the injection material is fed to the injection tube main body, the injection material expands the cylindrical elastic covering body having a circular cross section by the discharge pressure from each injection material discharge port, and the injection tube main body. It discharges between the cylindrical elastic cover and overcomes the elastic force of the entire surface of the cylindrical elastic cover so that the tube axis direction and the circumference of the injection tube main body are between the injection tube main body and the cylindrical elastic cover. A gap is made in the direction to reach the injection material injection slit.

  (3) Thereby, the injection material is fluid pressure that has overcome the elastic force of the cylindrical elastic coating material along the axial direction from the injection slit of each injection material of the cylindrical elastic coating material to the outside of the cylindrical elastic coating material. Is ejected to the entire axial length of the hole wall and injected into the columnar form. Also, if the seal grout is filled between the injection tube main body and the hole wall, the injection material breaks the seal grout solidified by the injection pressure by forming a crack in the tube axis direction, etc. Columnar penetration is injected into the ground around the hole wall.

  Conventionally, even if an injection material is injected from a columnar space into a drilling hole or through a seal grout, the injection material destroys a weak portion of the drilling wall or a weak portion of the seal grout, and passes through the destroyed portion. It was thought to flow intensively into the ground around the hole wall.

  However, the present inventor forms a cylindrical elastic covering (rubber slit tube) having a circular cross section such as a long rubber sleeve on the outer periphery of the injection tube in a predetermined range on the outer periphery of the injection tube. When the outlet is sealed, the rubber is pulled in close contact so that the tensile force acts, and the injection solution is fed to the injection tube. It is provided in the axial direction of the injection tube with a hydraulic pressure that opens a slit where the hydraulic pressure and tension act in the circumferential direction enough to spread the cover and create a gap between the elastic cover and the injection tube main body. When injected from each injection material injection slit, it is concentrated along the tube axis direction on the drilling wall and at the same time forms a permeation source over the entire length and penetrates into the ground in the form of a column, or the seal grout consolidated body is formed into the tube axis. Easily breaks in the entire length of the direction and soaks in a columnar shape in the ground around the hole wall I was able to be confirmed by the experiments that.

  (4) In this case, the injection material injection slits are preferably arranged so as to be perpendicular to the tube axis and along the tube axis (FIG. 1). By doing in this way, the seal grout (consolidated body) provided in the space of the drilling wall with the injection pipe is ejected in a concentrated manner along a plurality of slits set in a predetermined length in the pipe axis direction. It was also confirmed that a continuous crack was generated in the entire length in the direction, and the injected material could be infiltrated and injected into the ground using the crack as a columnar penetration source (FIGS. 3B, 6B, and 8). (B), FIG. 9 (b)).

  The injection tube main body of the injection tube may be a single tube, a bundled thin tube obtained by binding single tubes, or an outer tube for double packer in which a double packer inner tube is inserted.

  Further, the outer tube for double packer may be an injection tube provided with one or more bag packers. Furthermore, the injection tube body can be made of a soft synthetic resin, a biodegradable resin, or the like. Moreover, a double tube double packer injection tube may be used. Alternatively, a triple packer injection tube may be used in which an inner tube with a triple packer is inserted into the outer tube. The diameter of the single injection tube body is preferably about 1 cm to 4 cm. About 3 to 15 cm is used as the outer injection tube.

  In addition, the applicant conducted the experiment described below for the injection tube in the present invention, and confirmed the above-described effects.

Experiment. 1
FIG. 17 is a photograph of the injection tube shown in FIGS. The injection tube body is covered with a long cylindrical elastic covering material (long cylindrical rubber slit tube) having a circular cross section. Lateral slits were arranged in the tube axis direction.

  FIG. 18 is a photograph in which the injection state of water injected into the injection pipe shown in FIGS. 1 to 3 in the air and injected from the injection material injection slit is confirmed. It was confirmed that water was sprayed over the entire length from each of the injection material injection slits at a hydraulic pressure against the elastic resistance of the long cylindrical rubber that closed the plurality of injection pipe discharge ports.

Experiment. 2
An injection tube was installed in the sand packed in a plastic container having a transparent plastic plate on the side, and was added to the side made of transparent plastic, and was filled with sand so as not to create a gap around it. When water colored blue was injected from the injection tube, it was confirmed that the column penetrated as shown in the photograph of FIG. When the sand ground of a plastic container is filled with water and poured in the same manner, when poured into dry sand, the injected solution droops slightly (Fig. 19), but below the surface of the water, the diameter is almost the same. It was confirmed that the column penetrated (Fig. 20). Furthermore, it was confirmed that a columnar solid was formed when the injection solution was injected (FIG. 21).

  As described above, after the injection pipe of the present invention is stood as it is in a drilling hole formed in the ground, it penetrates in a columnar shape even if the hole wall collapses between the injection pipe and the hole wall and fills the gap around the injection pipe. Was confirmed.

Experiment 3
A large plastic container was filled with water, and the injection pipe of the present invention embedded in a columnar seal consolidated product (alkaline) by seal grout was installed in the water. A phenol phthalene solution was injected into the injection tube with a hand pump. During injection, it was confirmed that the seal grout had a red crack along the axial direction, and the injection liquid was leached along the axially generated crack (FIG. 22). After that, when the seal grout consolidated body was broken and observed, a red reaction was observed along the entire crack surface in the tube axis direction, and it was confirmed that the injected solution was leached from the entire crack surface along the tube axis. (Fig. 23). From the above, it has been found that the injection liquid ejected at a hydraulic pressure that overcomes the elastic force of the cylindrical elastic covering causes columnar permeation in the seal grout consolidated body over the entire length of the covering, causing splitting in the vertical direction.

Experiment. 4
The surface of the injection tube was covered with water-permeable urethane foam, and blue water was injected with a hand pump in the same manner as in Experiment 2 to confirm the state of penetration. As a result, it was confirmed that the injection material injected from the injection material injection slit permeates in a columnar shape in the axial direction of the injection tube.

  From FIG. 24, it is injected so that it penetrates the urethane foam and penetrates the entire length of the drilling wall with a hydraulic pressure just enough to overcome the resistance of the tensile force in the tangential direction of the circumference of the cylindrical elastic body with a circular cross section immediately after injection. And understand the situation of intrusion. FIG. 25 shows the state of infiltration after 5 minutes of infusion. It can be seen that the injected liquids that have been jetted and jetted into the hole wall are then infiltrated between the soil particles evenly in parallel to each other in parallel and then permeate into the columnar shape.

  From the above experiment, even if there is a solid column of seal grout around the injection pipe with the force that the injection liquid blows out in the major axis direction with the hydraulic pressure overcoming the tensile force acting on the entire surface of the cylindrical body due to rubber elasticity, In addition, it was found that the injection liquid penetrated the columnar shape from the entire length of the long cylindrical elastic coating even when soil was broken around the injection pipe between the drilling wall and the injection pipe without the seal grout.

  Also, from the above experiment, the injection liquid (FIG. 18) ejected along the tube axis with a fluid pressure that overcomes the rubber elasticity breaks the drilled wall or the sealing grout column in the vertical direction (FIG. 22, 24), and then permeates into a laminar flow in the lateral direction to form a columnar consolidated body (FIGS. 25 and 19 to 21). That is, unlike the point injection, in the column penetration injection by the injection pipe of the present invention, the injection liquid that breaks down into the vertical report with the liquid that overcomes the elastic elasticity of the drilling wall or seal grout is injected vertically. Since the liquids are bound to each other, they penetrate in a laminar flow in the horizontal direction. For this reason, it turned out that the columnar solid object by columnar penetration is formed.

  In the present invention, columnar infiltration can be simultaneously injected over the entire length of a long rubber slit tube. Therefore, the injection material can be infiltrated between soil particles with a large discharge amount and low pressure. The conflicting effect of high quality construction due to interparticle penetration can be obtained. In addition, the present invention makes it possible to improve the ground by economically manufacturing the injection pipe and drilling it with a simple structure having a small diameter. The present invention having such an effect improves the water-stopping property of the ground by injecting a solidified liquid, increases the strength, prevents liquefaction by injecting non-solidifying materials such as air, microbubble liquid and soil purification material, soil purification, Further, it can be used for filling and filling the cavity.

FIG. 1 (a) is a side view with a part broken away, and FIG. 1 (b) is a partially enlarged view of the injection pipe provided in the ground injection device of the present invention. 1 shows the structure of the injection tube shown in FIG. 1, FIG. 2 (a) is a side view with a part broken away, and FIG. 2 (b) is a cross-sectional view. Fig. 3 shows the structure of the injection tube shown in Fig. 1. Fig. 3 (a) shows that the injection material sent to the injection tube body causes the seal grout around the hole wall to crack in the axial direction of the tube, causing columnar penetration injection into the ground. FIG. 3 (b) is a partially cutaway side view showing a state in which it is in operation, and FIG. FIG. 4 (a) is a side view showing a state in which the injection pipe according to the present invention in which a long sleeve is provided at intervals at a plurality of positions is installed in a drilling hole, the injection pipe provided in the ground injection device of the present invention; FIG. 4 (b) is a partially enlarged side view thereof. The structure of the injection tube shown in FIG. 4 is shown, FIG. 5 (a) is a partially broken side view thereof, and FIG. 5 (b) is a transverse eye view. Fig. 6 shows the structure of the injection tube shown in Fig. 4. Fig. 6 (a) shows that the injection material fed to the injection tube body causes the seal grout around the hole wall to crack in the axial direction of the tube, causing columnar penetration injection into the ground. FIG. 6 (b) is a partially cutaway side view showing a state in which it is in operation. FIG. 7 (a) shows a state in which the injection pipe of the present invention in which a long rubber slit tube is provided over the entire length of a plurality of stages is installed in a drilling hole. A broken side view and FIG. 7 (b) are partially enlarged side views. 7 shows the structure of the injection tube shown in FIG. 7. FIG. 8 (a) is a partially broken side view of an example in which a double packer inner tube is provided corresponding to one stage-length cylindrical elastic slit tube and injection is performed for each stage. Fig. 8 (b) is a cross-sectional view thereof The structure of the injection tube shown in FIG. 7 is shown. FIG. 9 (a) shows a cylindrical elastic slit tube covering two stages, and a double packer inner tube is provided so that a pair of double packers can be used simultaneously on two stages. FIG. 9 (b) is a partially cutaway side view to be injected, and FIG. FIG. 10 (a) shows the injection tube of the present invention having an injection outer tube provided with a bag packer 12, showing a state of being installed in the drilling hole, a partially cutaway side view, FIG. 10 (b) FIG. 10 (c) is a partially enlarged side view of the rubber slit tube. FIG. 10 (c) is an enlarged side view in which a part of the injection tube used as a columnar permeation source by installing a water permeable sheet, a water permeable mat, etc. on the outer periphery of the rubber slit tube. FIG. 11 shows an injection tube provided in the ground injection device of the present invention, which is a bundling injection tube composed of a plurality of injection capillaries, and FIG. 11 shows a core (post) 15 which is a side view showing a state of being installed in a drilling hole. . It is an injection tube with which the ground injection device of the present invention is provided, and is a side view showing a state in which a bundled injection thin tube in which a plurality of injection thin tubes are bundled with a core material is installed in a drilling hole. It is a schematic diagram of a ground injection device arranged so that injection material can be injected into the ground at a plurality of points at the same time, or at a part or a plurality of points at the same time or selected. It is a schematic diagram of a ground injecting device configured to be able to inject an injection material into the ground at a plurality of points at the same time, or at the same time or at a part or a plurality of points, or continuously. FIG. 15 is a schematic diagram of a ground injection device configured to be able to inject injection material into the ground at a plurality of points simultaneously, or at a part or a plurality of points simultaneously or selectively. FIG. 16 (a) shows a method of injecting an injection material into the ground directly under an existing structure, FIG. 16 (a) shows a method of injection using the injection tube shown in FIG. 4, and FIG. 16 (b) shows an injection tube shown in FIG. 16 (c) is a side view showing a method of injecting using the injection tube shown in FIG. 11, and FIG. 16 (d) is a plan view thereof. It is a photograph which shows the injection tube shown in FIG. 1 comprised by sticking a long rubber slit tube to the outer periphery of an injection tube main body. It is the photograph which injected the injection pipe shown in FIG. 1 and confirmed the injection condition of the water injected from an injection material injection slit. It is the photograph which confirmed that water poured into the injection pipe shown in Drawing 1 installed in dry sand ground, and water permeated into the circumference. It is the photograph which confirmed the state which poured water into the injection pipe shown in FIG. 1 installed in the sand ground underwater, and the water osmose | permeated the circumference | surroundings. FIG. 20 is a photograph in which it is confirmed that a columnar consolidated body is formed by injecting an injection solution in FIG. The injection tube shown in FIG. 1 embedded in the columnar solidified product by seal grout is placed in water and the phenolic solution is injected by a hand pump, and the columnar solidified product of the seal grout cracks along the tube axis direction. It is the photograph which confirmed that the phenol liquid leached along the crack produced in the direction of a pipe axis by red reaction. FIG. 23 shows a cross section of the seal grout columnar consolidated product shown in FIG. 22 broken along a crack. It is the photograph which confirmed that the injection | pouring liquid leached out from the whole surface of the crack which arose along the pipe-axis direction along the whole crack surface of a pipe-axis direction. FIG. 19 is a photograph in which the surface is covered with a water-permeable urethane foam under the same conditions as in FIG. It is the photograph which confirmed the penetration condition at the time of injecting for 5 minutes in FIG.

  1 to 3 show an embodiment of the present invention, which shows an injection pipe connected to an injection material supply plant (not shown) via a liquid feed pipe (not shown). In the figure, the injection tube 1 is set up in a drilling hole 2 formed in the ground. Further, a seal grout 3 is filled in the gap between the hole wall of the hole 2 and the injection tube 1.

  The injection tube 1 is composed of an injection tube main body 4 and a cylindrical elastic covering (hereinafter referred to as “long rubber slit tube”) 5 having a circular cross section that is in close contact with the outer periphery of the injection tube main body 4.

  The injection tube body 4 is formed of a steel tube, a hard PVC tube, a soft plastic thin tube, a nylon thin tube, a biodegradable plastic tube, or the like, and a plurality of injection material discharge ports 4a are provided at the tip of the injection tube main body 4. It is formed at intervals in the axial direction and the circumferential direction, and the tip surface is closed. The injection material discharge port 4a shown in the figure is opened at a plurality of intervals in a predetermined section in the tube axis direction.

  The seal grout 3 is solidified in the hole 1 to fix the injection tube 1 in the hole 2 and prevent the wall wall of the hole 2 from collapsing, and at the tip of the hole 2 the injection material discharge port 4a. This serves to prevent the injected material discharged from the pipe from being displaced in the direction of the tube axis of the injection tube 1, and the seal grout 3 is low enough to be easily crushed by the injection pressure of the injected material even if it is solidified. Strong cement mortar, bentonite, low alkaline cement, lime, gypsum and the like are used.

  The long rubber slit tube 5 is formed in the injection tube body 4 to have a predetermined length so as to cover the plurality of injection material discharge ports 4a, and by the tensile force acting in the circumferential direction of the elastic force of the rubber having a circular cross section. Each injection material discharge port 4a is sealed by being in close contact with the outer peripheral surface of the injection tube body 4 (see FIGS. 2 (a) and 2 (b)).

  The long rubber slit tube 5 is formed with a plurality of injection material injection slits 5a so as not to overlap the injection material discharge ports 4a. The injection material injection slits 5a are formed to have a constant length in the circumferential direction of the injection tube main body 4, and a plurality of injection material injection slits 5a are formed at intervals in the tube axis direction and the circumferential direction of the injection tube main body 4.

  In such a configuration, when the injection material is supplied from the injection material supply plant (not shown) to the injection tube 1 through the liquid supply pipe (not shown), the injection material is supplied from the injection material discharge ports 4a of the injection tube body 4 to the full length. Between the outer peripheral surface of the injection tube main body 4 and the inner peripheral surface of the long rubber slit tube 5 by pushing and spreading the rubber slit tube with a hydraulic pressure that overcomes the tensile force of the long rubber slit tube 5 closely adhered to It is discharged (see FIGS. 3 (a) and 3 (b)).

  The discharged injection material flows along the outer peripheral surface of the injection tube main body 4 and the inner peripheral surface of the rubber slit tube 5 in the tube axis direction and the circumferential direction of the injection tube main body 4, and the long rubber slit tube 5 is pulled. While maintaining the pressure and the fluid pressure, the pressure is further concentrated along the tube axis direction by the pressure that pushes the blockage of each injection material injection slit 5a, and is ejected to the outside. As a result, continuous cracks are formed in the seal grout 3 solidified by the injection pressure in the direction of arrangement of the injection material injection slits 5a, and through the cracks, columnar penetration is injected into the ground around the hole wall (Fig. 3 (a) (See (b)).

At that time, in particular, the longitudinal crack formed along the long rubber slit tube 5 becomes a columnar penetration source, and a large amount of injection material is injected into the ground around the hole wall from the plurality of injection material injection slits 5a. It is sprayed along the entire length of the long rubber slit tube 5 and is infused uniformly over a wide area at a low pressure into the ground from a wide infiltration cross section.
Further, when the injection from the injection material supply plant (not shown) is stopped, the long rubber slit tube 5 is brought into close contact with the outer peripheral surface of the injection pipe main body 4 by its rubber elasticity acting over the entire length of the long length. Since the injection material discharge port 4a is completely sealed, the injection material discharged outside the injection tube 1 does not flow back into the tube (FIGS. 2 (a) and (b)).

  The range of the injection tube main body 4 having the injection material discharge port 4a and the length L in the tube axis direction of the long rubber slit tube 5 are the length of the injection stage, the ground conditions such as the soil layer, gap and density. In consideration, it can be set to an appropriate dimension (Fig. 1 (a), Fig. 4 and Fig. 7). The diameter and interval of the injection material discharge port 4a and the length and interval of the injection material injection slit 5a are set so that the injection material is injected over the entire length and the entire circumference of the stage in the pipe long axis direction into the ground around the hole wall. (Figure 7).

  4 to 6 are other embodiments of the present invention, and illustrate an injection pipe connected to an injection material supply plant (not shown) through a liquid feed pipe (not shown). In the figure, the injection tube 1 is provided with an injection outer tube 7 and an injection inner tube 8, and the injection outer tube 7 is set up in a drilled hole 2 formed in the ground, and the injection inner tube 8 is inserted into the injection outer tube 7. It is set up. In addition, a seal grout 3 is filled in a gap between the hole wall of the drilling hole 2 and the injection outer tube 7. The injection tube outer tube 7 corresponds to the injection tube main body 4 of the injection tube described with reference to FIGS.

  The outer injection pipe 7 and the inner injection pipe 8 are each formed of a steel pipe, a hard PVC pipe, a soft and flexible plastic resin pipe, a biodegradable plastic pipe, or the like. The discharge ports 7a are formed radially at intervals in the tube axis direction and the circumferential direction.

  A plurality of long rubber slit tubes 5 are closely attached to the outer periphery of the injection outer tube 7 at intervals or continuously in the tube axis direction. Each long rubber slit tube 5 is in close contact with the plurality of injection material injection material discharge ports 7a so as to cover a plurality of injection material injection material discharge ports 7a in the tube axis direction, and is in close contact with the outer peripheral surface of the injection outer tube 7 by the elastic force of rubber. The injection material discharge port 7a is sealed (FIGS. 5 (a) and (b)).

  The injection inner tube 8 has a plurality of injection material discharge ports 8a that open laterally at the tip, and expansion / contraction packers 8b and 8b on both upper and lower sides of the injection material discharge port 8a. It is a tube.

The expansion / contraction packers 8b and 8b are formed by attaching a rubber tube or the like to the outer periphery of the injection inner tube 8 in an annular shape.
Alternatively, it expands by enclosing air or liquid from the ground via a separate liquid supply pipe, and contracts by extracting air or liquid in the expansion / contraction packers 8b, 8b, and contracts the expansion / contraction packers 8b, 8b. In this state, the injection inner tube 8 can be moved up and down to move the injection stage.

  In such a configuration, when the injecting material is fed from the ground into the injecting inner tube 8 with the expansion / contraction packers 8b, 8b expanded, the injecting material passes through the injecting material channel 9 described later, and a plurality of injecting materials. A columnar permeation source is formed by forming a crack in the arrangement direction of the injection material injection slits 5a in the seal grout 3 which is injected from the injection slit 5a to the outside of the rubber slit tube 5 at a high pressure and solidified by the injection pressure. Through the crack, it is injected into the ground around the hole wall (see FIGS. 6 (a) and 6 (b)).

  The injection material flow path 9 includes an injection material discharge port 8a, a gap 10 between the injection outer tube 7 and the injection inner tube 8 sealed by upper and lower packers 8b, 8b, an injection material discharge port 7a, an injection outer tube 7 and a long length. It consists of a gap 6 between the rubber slit tubes 5 and an injection material injection slit 5a (FIGS. 6A and 6B).

  Further, the injection inner tube 8 is moved up and down to move the position where the injection material discharge port 8a and the expansion / contraction packers 8b and 8b are set in the direction of the tube axis of the injection outer tube 7, and the injection material passes through the injection inner tube 8 for each stage. Can be injected into the ground of each stage. The long rubber slit tube may be divided corresponding to different soil layers L1,... L4 in FIG. Further, the density and size of the slits may be set depending on the soil layer. In this way, the inner tube packer is installed at a position sandwiching multiple sections and injected, so that the optimal injection amount for each soil layer does not move so that the same columnar consolidated diameter is obtained. Can also inject a predetermined section at a time.

  When the injection from the injection material supply plant (not shown) is stopped, the rubber slit tube 5 is brought into close contact with the outer peripheral surface of the injection outer tube 7 by its elastic force, so that the injection material discharge port 7a of the injection outer tube 7 is completely formed. The injection material discharged to the outside of the injection outer tube 7 does not flow back into the tube (FIGS. 5A and 5B).

FIGS. 7 to 9 show modifications of the injection tube described in FIGS. 4 to 6, and the long rubber slit tube 5 is an object of ground injection of the injection outer tube 7 on the outer periphery of the injection outer tube 7. Is in close contact with the entire length.
The long rubber slit tube 5 is partitioned into a plurality of sections in the tube axis direction by the divided fasteners 11 so that the injected material does not flow into the upper and lower sections beyond the divided fasteners 11.

  Further, the long rubber slit tube 5 can be freely adjusted in length according to the depth of the ground by connecting a plurality of short rubber slit tubes so as to be detachable in the tube axis direction by the split fastener 11. May be formed.

  In this structure, the long rubber slit tube 5 is divided into a predetermined injection stage length by the divided fastener 11, and the upper and lower long rubber slit tubes 5, 5 are separated by the divided fastener 11. The length of one division of the long rubber slit tube 5 is preferably about 30 cm to 2 m.

  The injection material discharged into the long rubber slit tube 5 can be divided into upper and lower long rubber slit tubes 5 and 5 by a split fastener 11 and discharged from each of them. If it is installed so as to sandwich a plurality of rubber slit tubes divided into positions, the injection stages of a plurality of divided parts can be injected simultaneously.

  8 (a) and 8 (b) are examples in which the injection inner tube 8 is moved up and down for each stage to inject the injection material into the ground around the hole wall, and FIGS. 9 (a) and 9 (b) In this example, the expansion / contraction packers 8b and 8b of the injection inner tube 8 are installed so as to extend over a plurality of injection stages nL, and the injection material is simultaneously injected into the plurality of injection stages. If the soil quality of the plurality of injection stages is homogeneous, the plurality of injection stages can be injected simultaneously and homogeneously.

  FIGS. 10 (a) and 10 (b) illustrate a modification of the injection tube, and a plurality of bag packers 12 and 12 are attached to the outer periphery of the injection outer tube 7 at intervals in the tube axis direction. A long rubber slit tube 5 is attached between the bag packers 12 and 12.

  The bag packers 12 and 12 are expanded larger than the inner diameter of the hole 2 by enclosing a mortar or other solidified material, and the gap between the hole wall of the hole 2 and the injection outer tube 7 is completely sealed for each stage. It is configured as follows.

  Then, when each bag packer 12, 12 is inflated and the injection material is fed to the injection inner tube 8 while being sealed with the bag packer for each stage, the injection material is each injection material injection slit of the long rubber slit tube 5. By spraying at a high pressure on the hole wall between the bag packers 12 and 12 from 5a, even if the hole wall collapses, the rubber slit tube 5 between the bag packers 12 and 12 extends over the entire length of the rubber slit tube 5 into the ground around the hole wall. Penetration penetrates.

  The space between the upper and lower bag packers 12 and 12 in the hole 2 may be left as it is or may be filled with a seal grout 3 as shown in the figure. The bag packer may be made of cloth, or may be rubber or a water-impermeable elastic bag. Further, the number of bags may be one or more.

  Further, as shown in FIG. 10 (c), a water-permeable sheet 13 made of a woven fabric, a nonwoven fabric, a mat or the like can be attached to the outer periphery of the long rubber slit tube 5 to form a columnar permeation source. Further, a water permeable sheet may be attached to the injection tube of FIG.

  FIG. 11 shows an example in which the injection pipes described in FIGS. 1 to 3 are bound and used, and a plurality of injection pipes 1 are set up in a single hole 2 as shown in the figure. (Bundling injection tube). Further, the injection pipes 1 and 1 may be bound to each other in a state where a gap is maintained so that the seal grout is easily filled between the injection pipes 1 and 1. Further, a seal grout 3 is filled between the hole wall of the hole 2 and each injection pipe 1 and between each injection pipe 1, 1. Even when the seal grout is not used, a water-permeable material such as sand may be dropped between the drilling walls when the injection pipe is installed in the drilling hole.

  FIG. 12 shows an example in which the injection tube is reinforced by tying the injection tube 1 with a reinforcing core (support bar) 15. As the core material 15, a reinforcing bar, a steel rod, a hard plastic rod, a biodegradable core material, or the like is used.

  FIG. 13 illustrates an example of the ground injection method implemented using the injection pipes described in FIGS. 1 to 3, 11, and 12. As illustrated, a plurality of injection pipes 1 have a certain area. It is installed at regular intervals in the ground. Further, the plurality of injection tubes 1 may be installed at different depths.

  Then, when the injection material is fed to the injection pipe 1 at each injection point, the injection material is infused into the ground around the hole wall from the long rubber slit tube 5 in the ground at each injection point. It is possible to improve the ground of a large area such as extremely efficiently and quickly. In particular, by extending the length of the long rubber slit tube 5 according to the thickness of the injection stage (the formation), it is possible to inject and inject a large amount of injection material into the ground around the hole wall at a low pressure. By increasing the interval D between the injection pipes 1, the ground improvement of a wide ground such as a creation site can be performed very efficiently and economically.

  FIG. 14 illustrates another embodiment of the present invention, and particularly includes a plurality of bundling injection tubes described in FIGS. 2 to 4 and 6. According to the ground injection device, ground improvement and ground purification of a ground having a large area can be performed very efficiently and in a short period of time.

  If it demonstrates concretely, the above-mentioned bundling injection pipe | tube 1 is each inserted in the some drilling hole 2 formed in the ground of the predetermined area | region at intervals. Further, a common liquid feed pipe 17 extending from the injection material supply plant 16 is connected to each bundle injection pipe 1, and the injection material is supplied from the injection material supply plant 16 to the bundle injection pipe 1 at each injection point to the liquid supply pipe 17. Liquid feed pump 24 for feeding liquid, flow rate / pressure gauge 19 for measuring the flow rate and pressure of the injection material fed to each bundling injection pipe 1, start and stop of liquid feeding to each bundling injection pipe 1 Further, a flow path switching valve 25 for switching the flow rate, and a flow rate adjusting valve 26 for adjusting the liquid feeding to each injection thin tube in each of the bundled injection tubes 1 are connected.

  The flow rate adjusting valve 26 may be a simple liquid supply valve, an orifice, or a squeezed portion that can adjust the opening degree. When pores such as orifices and squeezed parts are provided, a constant discharge amount corresponding to the pumping pressure and the area of the pores can be obtained. 1 can be injected simultaneously.

  Further, a centralized management device 23 for controlling these devices to an appropriate state is connected to the liquid feed pump 24, each flow rate adjustment valve 26, and each flow path switching valve 25.

  In such a configuration, by appropriately controlling the liquid feed pump 24, the flow rate / pressure gauge 19, the flow path switching valve 25 and the flow rate adjustment valve by the centralized management device 23, an injection material having a predetermined flow rate is supplied to each injection point. In addition to feeding the liquid, an injection material having a predetermined flow rate can be injected into each stage around the hole wall at each injection point. Further, by operating the flow path switching valve 25, the injection to one or a plurality of points can be continuously injected, selectively injected or stopped, or the flow rate can be adjusted.

  FIG. 15 also shows another embodiment of the present invention. In particular, the unit pump 18, the flow rate / pressure gauge 19 and the flow rate adjustment valve are supplied from the injection material supply plant 16 for each bundle injection pipe 1. By being connected to the pipe 17, each bundling injection pipe 1 constitutes an independent ground injection apparatus, and each bundling injection pipe 1 and 1 is connected by a common liquid feeding pipe 17 and each bundling injection. Since the flow path switching valve 25 is connected to the connection portion with the pipe 1, even if a part of the ground injection device stops due to a failure or maintenance of the unit pump 18 or the valve, the liquid feeding pipe 17 The ground can be continuously injected by feeding the injection material to the bundled injection tube 1 that is stopped through the spar.

  In FIG. 15, a multi-continuous pump composed of unit pumps 18 that are independently driven is injected into the ground through an injection pipe corresponding to each unit pump 18 using an injection device that is collectively managed by a centralized management device. The injection tube may be a bundled injection capillary or a single tube injection tube of the present invention. The liquid feeding from each unit pump 18 may be performed to a plurality of injection capillaries of the injection soil layer, or can be simultaneously or selectively injected into different discharge ports in the axial direction of one injection capillaries.

  Figures 16 (a) to 16 (d) illustrate the ground injection method implemented for the existing building 26 and the ground directly under the structure, such as an existing building or storage tank. A plurality of holes are formed at intervals from the surrounding ground surface of 27 toward the lower side of the existing building, and a plurality of injection pipes 1 are inserted into each hole. A seal grout is filled between the hole wall of the hole and the injection tube 1.

  Of these, FIG. 16 (a) is an example using the injection tube described in FIGS. 4-6, FIG. 16 (b) is an example using the injection tube described in FIGS. 7-9, and FIG. (c) is an example using the injection tube described in FIGS. 11 (a) and 11 (b).

  In any example, when the injection material is supplied from the injection material supply plant (not shown) to each injection tube 1 via the liquid supply tube, the injection material is discharged from each injection tube body 4 in each injection tube 1. It discharges out of the injection tube main body 4 from the outlet 4a, and the rubber slit tube 5 is expanded by the discharge pressure of the injection material, so that a gap 6 is formed between the outer peripheral surface of the injection tube main body 4 and the inner peripheral surface of the rubber slit tube 5. (See FIGS. 6A and 6B).

  The injection material flows in the gap 6 between the outer peripheral surface of the injection tube main body 4 and the inner peripheral surface of the rubber slit tube 5 in the tube axis direction and the circumferential direction of the injection tube main body 4, and the long rubber slit tube 5. Each of the injection material injection slits 5a is discharged out of the rubber slit tube 5, and a crack is formed in the seal grout 3 solidified by the injection pressure in the tube axis direction where the injection material injection slits 5a are arranged. By infiltrating and injecting into the ground of each stage around the hole wall through the crack, the ground improvement can be carried out economically with a small hole diameter with respect to the direct foundation board of an existing building or structure.

  As described above, according to the present invention, the cylindrical elastic covering (rubber film or the like) having a circular cross section is adhered to the outer periphery of the injection tube by an elastic force (rubber elasticity or the like) so as to seal a plurality of injection material discharge ports. Therefore, since the injection material discharge port is sealed with an elastic covering, the injection liquid is drilled with an injection pressure that overcomes the tensile force generated in the tangential direction of the circumference of these long cylindrical rubber elastics. In order to inject into the seal grout, even if the drilling wall or the seal grout (consolidated body) has some variation in strength in the depth direction of the drilling wall due to the injection pressure, the cylindrical body along the axial direction A continuous crack occurs in the entire length of the column, and the column penetrates from there. In addition, because the long cylindrical rubber elasticity acts on the entire surface of the injection tube, the discharge port is sealed by a large non-return effect, so that the injection material discharged into the ground and the injection solution from other injection tubes are not contained in the injection tube. Never flow backwards. Therefore, it is not necessary to attach a check valve to each discharge port, and it is not necessary to form a mat in order to create a columnar penetration source along the long axis direction. In addition, when the suspension is injected, if there is looseness in the slit tube, after discharge, the suspension remains between the discharge port and the slit of the slit tube and the wall of the tube. However, if the cylindrical elastic slit tube with a circular cross-section has a tensile force acting after discharge, the remaining suspension will be discharged from the slit and the check effect will be reduced. It was found that it was not obstructed. In addition, the suspension does not clog the mat as in the conventional injection tube, and the suspension does not lose the check function due to the elasticity of the long cylindrical elastic rubber acting on the outer periphery of the injection tube in the entire predetermined injection region. Repeated injection of liquid, primary injection of suspension, and secondary injection of solution grout are also facilitated. In addition, since the tensile force acts over the entire length of the slit tube in this way, it has excellent non-consolidating permeability such as soil purification liquid, gas and gas mixed liquid from its excellent non-return effect. After injecting the injection solution, the injection solution will not flow back into the injection tube, and if the effect is insufficient, it can be repeatedly injected many times in the same injection tube. Applicable. Although the slit can be provided in the longitudinal direction or the lateral direction of the rubber surface, as described above, the slit is preferably in the direction along the circumference of the tube diameter, that is, in the lateral direction. This is because if the slit is in the vertical direction, the slit opens vertically and the tensile force in the circumferential direction is cut off, so that the effect of rubber elasticity is lost because the pipe tends to loosen in the radial direction. Further, a thin film of heat-shrinkable resin having a slit as a cylindrical covering material is not suitable. This is because the resin thin film shrinks and closes to the tube wall when the injection tube is coated and heat is applied. However, after the injection material is injected, the contact is lost with the slit open, so the non-return effect It is because it cannot be obtained. On the other hand, the rubber cylindrical covering material does not lose elasticity regardless of the presence or absence of heating, and does not lose the check effect before and after injection. Further, the injection pipe of the present invention has an injection liquid discharged from the injection discharge port against the outer seal grout by the expansion force of the long cylindrical elastic body that is generated when the injection liquid is ejected from the slit while resisting the elastic elasticity. An effect of facilitating penetration from the crack surface in the major axis direction by generating a continuous crack in the direction is also produced.

  In addition, since the elastic covering can be formed in a cylindrical shape in close contact with the injection pipe with a thin rubber sheet or the like, the diameter of the injection pipe can be reduced, and accordingly, a hole for drilling the injection pipe is inserted. Since the diameter may be small, drilling becomes easy and cost reduction can be achieved. In addition, since the diameter of the injection tube can be reduced, flexibility can be imparted to the injection tube, and the injection tube can be drawn into a hole cut in a curved shape.

  The present invention is suitable mainly for improving the water-stopping property of the ground, increasing the strength, preventing liquefaction, filling the cavity and purifying the ground, etc., and injecting a large amount of injection material into the ground around the hole wall at a low pressure. It is possible to infiltrate in a wide range and uniformly. The present invention can be effectively implemented not only for any solidifying injection material, but also for unsaturation methods such as non-consolidating air and microbubbles and injection of soil purification material.

1 Injection tube 2 Drilling hole 3 Seal grout 4 Injection tube body
4a Injection material outlet 5 Long rubber slit tube (cylindrical elastic sheath)
5a Injection material injection slit 6 Gap 7 Injection outer tube 8 Injection inner tube 9 Injection material flow path
10 gap
11 Split fastener
12 bag packer
13 Water-permeable sheet
14 Bundling bracket
15 Core
16 Input supply plant
17 Liquid feed pipe
18 Unit pump
19 Flow pressure gauge
20 Open / close valve
21 speed transmission
22 Drive source
23 Centralized management device
24 Liquid feed pump
25 Flow path switching valve
26 Existing structures

Claims (11)

  In a ground injection apparatus provided with an injection pipe for injecting and injecting injection material into the ground around the hole wall by being installed in a drilling hole formed in the ground, the injection pipe has a plurality of injection material discharges in the pipe axis direction. An injection tube main body having an outlet, and a cylindrical elastic covering member having a circular cross section having a plurality of injection material injection slits in the tube axis direction in close contact with the outer periphery of the injection tube main body and not overlapping the injection material discharge port The cylindrical elastic covering is formed so as to be in close contact with the outer peripheral surface of the injection tube body by elastic force to seal the injection material discharge port, and the plurality of injection materials fed to the injection tube body are the plurality of injection materials. The cylindrical elastic covering is spread from the injection material discharge port by a discharge pressure and discharged between the cylindrical elastic covering and the injection tube main body, and between the cylindrical elastic cover and the injection tube main body. Flow in the tube axis direction and circumferential direction of the injection tube body By simultaneously injecting along the tube axis with a hydraulic pressure that overcomes the elastic force of the cylindrical elastic covering from the plurality of injection material injection slits, the column penetrates into the ground around the hole wall, and enters the injection tube main body. When the liquid feeding is stopped, the cylindrical elastic covering closely adheres to the outer peripheral surface of the injection tube main body by its elastic force and closes the injection material discharge port, so that the injected material injected out of the cylindrical elastic covering is the injection tube. A ground injection device characterized by being configured not to flow back into the body.   The ground injection device according to claim 1, wherein the injection material filled with the seal grout between the injection tube main body and the hole wall and injected from the injection material injection slit to the outside of the cylindrical elastic covering is caused by the injection pressure. An injection tube apparatus, wherein the seal grout is formed to form a crease along a tube axis and penetrates into the ground around the hole wall from the crease.   3. The ground injection device according to claim 1, wherein the cylindrical elastic coating is formed in close contact with a predetermined length in the tube axis direction of the injection tube body, and is continuously provided in a plurality of sections in the tube axis direction of the injection tube body. A ground injection device characterized by being divided or in close contact with each other at intervals.   The ground injection apparatus as described in any one of Claims 1-3 WHEREIN: The outer peripheral part of a cylindrical elastic coating body is covered with the water-permeable material, The ground injection apparatus characterized by the above-mentioned.   The ground injection device according to any one of claims 1 to 4, wherein the injection material is configured to infiltrate and inject into the ground around the hole wall through an injection inner tube with a packer installed in the injection tube main body. A ground injection device characterized by that.   The ground injection device according to any one of claims 1 to 5, wherein one or a plurality of bag packers are installed on the outer periphery of the injection tube main body.   The ground injection device according to any one of claims 1 to 5, wherein the plurality of injection tube main bodies are bound to each other such that the cylindrical elastic covering bodies of the injection tube main bodies are arranged at different positions in the tube axis direction. A ground injection device characterized by   A ground injection device according to claim 1, wherein the ground injection device according to claim 1 is installed in a borehole formed in the ground, and a seal grout or sandy soil is filled in a gap between the ground injection device and the borehole. Construction method.   The ground injection device according to any one of claims 1 to 8 is installed at a plurality of injection points, and the injection material is injected into a plurality of points simultaneously or by selecting one or a plurality of points. The ground injection method.   6. A ground injection method characterized by simultaneously or selectively injecting one or a plurality of cylindrical elastic coatings from an inner tube inserted into an injection tube main body of claim 5.   A ground injection method, wherein the ground injection device is installed in a ground where a building is provided using the ground injection device according to any one of claims 1 to 10, and an injection material is injected into the ground.