JP4827109B1 - Injection pipe device and ground injection method - Google Patents

Abstract

An injection pipe device and a ground injection method capable of efficiently injecting into a predetermined injection stage over a wide range without deviating from the target of injection under low-pressure injection.
An injection outer tube 2 installed in a drilling hole 1 and an injection inner tube 3 installed in the injection outer tube 2 are configured. The injection outer tube 2 includes a primary injection material discharge port 2a and a secondary injection material discharge port 2b provided at intervals in the tube axis direction, a check valve 5 for preventing a back flow at the injection material discharge port, A columnar space water guide member 6 that covers a certain range in the tube axis direction including the upper surface of the secondary injection material discharge port 2b, or a seal grout intrusion prevention covering member 7 that covers the columnar space water guide member 6 is provided. The sealing grout intrusion prevention covering member 7 is configured to pass a secondary injection material injected into the ground through the injection inner pipe 3. A seal grout 4 is filled in the gap between the hole wall of the hole 1 and the outer injection tube 2.
[Selection] Figure 1

Description

  The present invention relates to an injection pipe device and a ground injection method, and can uniformly inject a large volume of injection material under a low pressure injection into a wide area without escaping.

  The chemical solution injection method improves the water stoppage, increases the strength, by injecting cement-based solidified material, water glass-based chemical solution, and also air bubble mixed solution into the ground by an injection tube inserted into the drilling hole. Is a ground improvement method that can prevent liquefaction.

  For example, in Patent Document 1, as shown in FIG. 19, a plurality of injection pipes 20 each provided with a check valve (not shown) for preventing a backflow of the injection material discharge port 20 a and the injection material are drilled 21. The injection port 20a of each injection tube 20 is set so as to be positioned at a predetermined interval in the tube axis direction, and the injection material is injected into the ground by each injection tube 20 to There is described an injection pipe device configured such that an injection material is discharged into the ground from the injection material discharge port 20a by expanding the stop valve.

  Further, Patent Document 2 discloses an injection tube device comprising an injection outer tube 22 inserted into the hole 21 and an injection inner tube 23 inserted into the injection outer tube 22 as shown in FIG. ing.

  The injection outer tube 22 includes a plurality of injection material discharge ports 22a formed at predetermined intervals in the tube axis direction, and an outer tube packer made of a bag attached to both upper and lower sides of each injection material discharge port 22a. 22b, 22b, and each outer tube packer 22b expands larger than the inner diameter of the hole 21 by filling with cementitious solidified material or the like.

  Further, the outer tube packers 22b and 22b expand and block the gap between the hole wall of the drilling hole 21 and the injection outer tube 22 on both upper and lower sides of the injection material discharge port 22a, so that the space between the hole wall and the injection outer tube 22 is increased. A columnar permeation source (columnar space) 24 that is continuous for a certain length in the tube axis direction is formed.

  The injection inner tube 23 includes an injection material discharge port 23a at the tip and inner tube packers 23b and 23b on both upper and lower sides of the injection material discharge port 23a. The inner tube packer 23b is filled with air or fluid from the ground. Thus, the gap between the injection outer tube 22 and the injection inner tube 23 is closed on both the upper and lower sides of the injection material discharge ports 22a and 23a, so that the injection material is introduced into the columnar penetration source 24 via the injection inner tube 23. Can be supplied.

  Then, in the injection stages A, B, and C, the injection material is injected from the ground into the column penetration source 24 by the injection inner tube 23, so that the surrounding ground from the hole wall of the drilling hole 21 even when injected at a high discharge speed. It can be osmotically injected (infiltration between soil particles) at low pressure.

  Further, Patent Document 3 discloses an injection tube device in which a hole wall protection member 25 is installed in the columnar penetration source 24 between the upper and lower outer tube packers 22b, 22b to prevent the hole wall from collapsing, Further, Patent Document 4 describes an injection apparatus and an injection method that use a plurality of injection pipes 26 as shown in FIG. 21 and simultaneously inject injection materials into a plurality of injection points.

  By the way, the ground is generally composed of a plurality of formations having different particle sizes and water permeability, and the difference in properties forms a heterogeneous state in the strength of the original ground and water permeability.

  For such ground, first of all, as a primary injection, an economical and relatively high strength material such as cement bentonite, or a quick-setting grout is injected to coarsely fill voids such as rough strata and water channels. In this way, the soil layer is made uniform to prevent the secondary injection material from moving out of the entry range and to the ground surface, and to prevent dilution of the injection material by groundwater.

  Then, by injecting an injection material excellent in permeability as a secondary injection material and injecting at a relatively low injection speed, the infiltration injection between the soil particles is ensured, and a rational ground improvement is performed.

Japanese Patent No. 2852721 Japanese Patent No. 3509744 Japanese Patent No. 3889408 Japanese Patent No. 3724644 Patent No. 2700614 Patent No. 2700614

  However, the injection pipe devices described in Patent Documents 1 and 4 are devices that inject an injection material at a preset point using a high-pressure pump, a pressure / flow rate monitoring device, and a management system that monitors and controls them. Therefore (FIGS. 19 and 20), when the injection is performed at a high discharge speed, the injection becomes a high-pressure injection and falls into a pulsed injection, and it becomes difficult to uniformly inject the injection material into the entire ground.

  For this reason, since low pressure injection is forced with a small amount of discharge, it takes a long time for injection, and the injection efficiency per one injection tube is very poor.

  In addition, the injection tube device described in Patent Document 2 and Patent Document 3 (FIGS. 20 and 23) forms a columnar permeation source (columnar space) 24 that is continuous for a certain length in the tube axis direction around the injection tube, This is a device for injecting and injecting the injection material into the surrounding ground through the columnar infiltration source 24. The columnar infiltration source 24 so far has a columnar space between the injection tube and the hole wall by the outer tube packer. Since it is formed by sealing a certain section in the direction, there is a problem that the structure of the apparatus is complicated and the work procedure is increased.

  In addition, in the ground where the strata having different water permeability are finely volumed, it is troublesome to form the columnar infiltration source for the reason that it is difficult to assemble the injection stage finely and perform the optimal injection.

  Furthermore, the injection material injected into another injection stage or another drilling hole may wrap around the columnar infiltration source and fill the space, making subsequent columnar injection impossible.

  By the way, since the ground usually has a different permeability coefficient and porosity for each layer, the ground condition is different for each layer. When injecting chemicals into this kind of ground, as shown in FIGS. 22 (a) and 22 (b), the injection pipe 26 is individually injected into the ground and pulled up, or as shown in FIG. The injection material was injected at an arbitrary point while the injection stage was inserted through the injection tube 26 and the injection stage was moved up or down.

  Further, as shown in FIGS. 22C to 22E, after drilling by boring using the casing a, an injection pipe (double packer inner pipe) 26 installed in the seal grout 29 is inserted and rubber is inserted. The injection material was injected by moving up and down the injection stage while breaking through the seal grout 29 through the check valve 26a made of a sleeve. However, since these are all based on the point injection shown in FIG. 22A, there is a drawback of the point injection as described above.

  Moreover, the biggest problem in the injection method such as chemical solution injection is infiltration into a fine sand layer having a small water permeability coefficient or homogeneous infiltration into the ground composed of different formations.

  The water permeability to the fine sand layer is usually k = 10 −3 to 10 −4 cm / second, and in order to inject the chemical solution so as not to cause the destruction of the ground to such a soil layer, It is said that low pressure injection must be performed at a low discharge rate of 1 liter or less to several liters per minute.

  However, in the known infusion method described above, one set of infusion pump is used for each infusion tube. From the economical aspect of shortening the construction period as much as possible, and the performance limit of the pump. From 10 to 20 liters per minute, the discharge pressure increases and the ground may be destroyed. For this reason, the ground rises and the fine soil layer does not penetrate and solidify. Sometimes it was enough.

  In addition, when injecting into different soil layers, when the soil layer changes, it is practically difficult to change the injection rate in response to the soil layer change or to control the injection amount. In such cases, the injection material spreads in a large amount or only slightly penetrates in a certain layer. In such an injection state, there is a problem that continuity between adjacent solid bodies cannot be obtained. .

  In Patent Document 4, a plurality of injection pipes are arranged in the ground, and a plurality of unit pumps are provided in one plant when the ground improvement material is injected into the ground from the respective discharge ports through the plurality of injection pipes. The improvement material is pumped to each injection pipe by a multi-consecutive pump that simultaneously operates a large number of unit pumps, and is injected into the ground from the discharge port.

  In the above-mentioned known technique, it was necessary to use an injection material having a low clay and a gel time of 10 hours or more in order to obtain a large consolidated diameter with a long injection hole interval (1.5 m to 4.0 m).

  However, once the injection material with a long gel time starts to deviate from the ground surface or the rough layer in the ground, the gelation time cannot be shortened, so the injection must be stopped, and during that time the grout is generated in the injection capillary. There was a problem of inconvenience such as gelation.

  Therefore, there has been a demand for an injection method that can infiltrate between soil particles even when injected from a single injection point with a large discharge amount, and that can be injected at an optimal discharge pressure and injection rate for each injection point.

  22 (a) and 22 (b) show the principle of the point injection method. In the figure, the injection material injected into the ground by the injection pipe 26 is uniformly injected from the tip of the injection pipe 26 into the ground. Ideally, it is point injection from the injection material discharge port, so that spherical infiltration occurs. When the discharge amount is increased, high-pressure injection is caused and pulse-like injection is likely to occur.

  22 (c) to 22 (e) show a double pipe double packer method that is conventionally used. After drilling in the casing a (FIG. 22 (c)), the injection outer tube 26 whose discharge port 26a is covered with a check valve 26b made of a rubber sleeve is inserted into the casing a (FIG. 22 (e)), While filling the seal grout 29 (FIG. 22E), the casing a is pulled out.

  Then, after the seal grout 29 is solidified, an injection inner tube having a double packer is inserted into the injection outer tube 26 to inject the injection material into the ground (not shown). When the injection material is injected into the injection inner pipe, the check material 26 is opened by the discharge pressure, so that the injection material is injected into the ground. For this reason, the injection is performed by point injection, and there are problems similar to those shown in FIGS. 22 (a) and 22 (b).

  FIGS. 23A and 23B show the principle of the columnar injection method. In FIG. 23, the injection material injected into the ground by the injection pipe 26 is between the upper and lower outer pipe packers 27 and 27. Then, it is discharged into a columnar penetration source 28 formed in a predetermined length, and is injected from the columnar penetration source 28 into the surrounding ground. At this time, the injection material can be uniformly injected into the surrounding ground from the hole wall of the columnar penetration source 28.

  However, there is a possibility that an injection material from another injection stage or an injection material from an adjacent injection stage bypasses the outer tube packer 27 and is injected into the columnar penetration source.

  Further, when primary injection and secondary injection are performed using the same injection tube device, the primary injection material may clog the discharge port during the primary injection, and subsequent secondary injection may not be smooth.

  The present invention has been made to solve the above problems, and an injection pipe device and a ground injection method capable of performing columnar injection over a wide range and uniformly without escaping a large-capacity injection material by low-pressure injection. The purpose is to provide.

  In addition, even if the discharge rate is increased, it is possible to infiltrate between the soil particles, so even if the drilling interval is increased and the gel time is extremely long (10 to several tens of hours), a gel time of several hours is possible. In addition, even if the gelation time is long, there is no concern that the injected material will flow back to the adjacent injection material discharge port, and even if the soil layer of the target ground is complicated, reliable injection can be performed for each formation or every injection stage. It is an object of the present invention to provide an injection pipe device and a ground injection method that are made possible.

  Furthermore, while taking advantage of the multi-point injection pump by low-pressure osmotic injection of the injection material for the wide area ground developed so far, according to the injection situation of each injection point while maintaining the infiltration between the soil particles by low-pressure injection, It is possible to arbitrarily manage the injection speed, discharge pressure, stop and restart of injection, gelation time, etc. by each unit pump, and manage the operation of many unit pumps at the same time to grasp and manage the whole injection situation The purpose is to make the injection pipe device and the ground injection method.

  The injection tube apparatus according to claim 1, wherein the injection outer tube includes an injection outer tube installed in the drilling hole, and an injection inner tube installed in the injection outer tube. A primary injection material discharge port and a secondary injection material discharge port that are spaced apart in the axial direction, a check valve that prevents backflow from the injection material discharge port, and an upper surface of the secondary injection material discharge port A columnar space water conveyance member covering a certain range in the tube axis direction, and a seal grout filled in a gap between the hole wall of the drilling hole and the injection outer tube and the columnar space water conveyance member. It is.

  In the present invention, the primary injection material and the secondary injection material that have been injected into the ground from the same injection material discharge port have been injected from different injection material discharge ports, in particular, after the primary injection material. The secondary injection material to be injected can be efficiently and widely injected without causing clogging or the like.

  When the primary injection material is injected into the outer periphery of the injection outer tube by injecting the primary injection material by installing a column-shaped space water conveyance member (columnar penetration source) so as to cover a certain range in the tube axis direction including the upper surface of the injection material discharge port, the column shape is formed by the primary injection material. The space water conveyance member is clogged, and therefore, the secondary injection material to be injected later cannot be efficiently and widely injected into the surrounding ground.

  According to the present invention, a columnar space water conveyance member installed as a columnar permeation source of the secondary injection material by the primary injection material by providing the discharge port of the primary injection material and the discharge port of the secondary injection material separately. Does not cause clogging, so that the secondary injection after the primary injection can be osmotically injected over a wide range in a very efficient manner.

  Further, columnar space water guide members covering a certain range in the tube axis direction including the upper surface of the secondary injection material discharge port on the outer peripheral portion of the injection outer tube are provided at intervals in the tube axis direction, and the hole wall, the injection outer tube, By filling a seal grout between the columnar space water conveyance member and the columnar space water conveyance member is covered with the seal grout, the primary injection material does not enter the columnar space water conveyance member and cause clogging. .

  In addition, by filling the sealant with a low-strength seal grout that can be crushed by the discharge pressure of the injection material, after the primary injection material is injected, the secondary injection material is removed from the columnar space water conveyance member (columnar penetration source) to the outside. The seal grout is broken by the discharge pressure, and can be efficiently and uniformly infused over a wide area from a large columnar penetration source into the surrounding ground under a low pressure and at a high discharge speed.

  A steel pipe, a hard PVC pipe, a biodegradable injection pipe, or the like can be used for the outer injection pipe and the inner injection pipe. Further, the columnar space water guide member is installed to form a columnar penetration source covering a certain range in the tube axis direction including the upper surface of the secondary injection material discharge port on the outer peripheral portion of the injection outer tube. It is desirable to form a net or a sponge and have a cylindrical or band shape made of a material having high water permeability.

  In addition, a woven fabric, a nonwoven fabric, a water permeable urethane resin material, a water permeable synthetic resin material, various drain materials, etc., and a tube having a plurality of secondary injection material discharge ports and secondary injection material discharge slits as a whole. Further, a net-like body or a cage-like body made of a bag or a resin fiber, or a synthetic resin tape can also be used as the columnar space water conveyance member.

  The length of the columnar space water guide member is usually about 0.1 to 3.0 m, preferably 0.2 to 1.0 m, longer than the hole diameter of the injection tube, and the length is the thickness of the soil layer of the target stage. , Soil layer structure, water permeability, discharge amount per minute, discharge pressure, material and structure.

  A rubber tube or the like is suitable for the check valve that prevents the backflow of the injection material from the primary injection material discharge port and the secondary injection material discharge port, and the primary injection material discharged into the ground by attaching the check valve The secondary injection material and the seal grout before solidification can be prevented from flowing back into the injection pipe.

  In addition, Patent Document 6 of the conventional method describes a structure in which the spiral tape covers the discharge port of the injection tube. However, since the injection material is discharged from the gap between the spiral tapes, the upper and lower discharge ports or adjacent injection ports are described. The injection material injected from the discharge port of the tube flows back into the injection tube through the discharge port from the gap of the spiral tape, and therefore does not function as a check valve and does not function effectively as an injection tube.

  In the present invention, a column-shaped space water conveyance member is formed by covering a secondary injection material discharge port by installing a strip-shaped material having water permeability in a tube shape or a spiral shape in the tube axis direction, and the secondary injection material Since a check valve made of a rubber sleeve or the like is attached to the upper surface of the discharge port, it is possible to simultaneously prevent injection from a large columnar space water guiding member and backflow of the injection material into the injection pipe by the check valve.

  The seal grout is easily cracked and crushed by the discharge pressure of the injection material discharged from the injection material discharge port when the primary injection material and the secondary injection material are injected into the ground through the injection inner pipe. It is desirable to use low-strength cement material, bentonite, bentonite / cement material, lime, gypsum, or the like.

  The seal grout may be made of a material having a particle size that does not enter the columnar space water conveyance member and cause clogging, or a highly viscous blend. Alternatively, a material having an eye roughness that does not allow the seal grout to enter the columnar space water guide member may be used.

  In this case, the injection pipes may be inserted independently into the plurality of drilling holes, or a plurality of injection tubes may be inserted into one drilling hole. The interval between the injection material discharge ports of each injection pipe and the installation length of the columnar space water guiding member can be arbitrarily set according to the properties of the ground.

  In the present invention, the primary injection material is injected for the purpose of preventing deviation of the secondary injection material from being injected by filling a rough ground layer or water channel in the ground and making the ground uniform (coarse filling injection). Turbid grouting and flashing grouting materials are used.

  A homogeneous osmotic solidified body can be formed by injecting a permeable grout of the secondary injection into the ground pretreated by the primary injection.

  In the present invention, the primary injection material and the secondary injection material are injected from separate injection material discharge ports, and in the columnar penetration source (columnar space) from which the secondary injection material is discharged due to the presence of the seal grout solidified body. The primary injection material does not enter the surface.

  Further, in the present invention, the seal grout partitions the upper and lower sides of the plurality of columnar space water guiding members to prevent the injecting material from entering the upper and lower adjacent stages, and to ensure that the injecting material permeates the columnar stage at a low pressure. be able to.

  An injection pipe device according to claim 2 is the injection pipe device according to claim 1, further comprising a seal grout intrusion prevention covering member that covers the columnar space water guide member, and the seal grout intrusion prevention covering member is grounded through the injection inner pipe. It is configured to pass a secondary injection material injected therein.

  In particular, the present invention prevents the columnar space water conveyance member from being clogged by the backflow of the primary injection material discharged into the ground, and also has a large columnar space (columnar infiltration source) in the entire section where the columnar space water conveyance member is installed. Thus, the secondary injection can be osmotically and extensively injected following the primary injection.

In this case, for example, as described above, the seal grout intrusion-preventing covering member is a mesh-like or cloth-like sheet material made of a material that allows the secondary injection material to pass but not the seal grout material, and a water-permeable urethane coating material. Alternatively, a sheet material such as a rubber sheet or a vinyl sheet having slits or small holes formed so as to structurally prevent the seal grout material from flowing in can be used.

  Examples of the former include, for example, a sheet material made of woven fabric or nonwoven fabric, and examples of the latter include, for example, discharge pressure of the secondary injection material discharged from the inside of the injection outer tube into the slit or small hole. However, there is a valve having a fin-like check valve formed so as to prevent the inflow of the seal grout from the outside (see FIG. 14D).

  In addition, if a vinyl coating material with perforations that can be easily broken by the injection pressure of the injection material is used, it can be easily broken by the discharge pressure of the secondary injection material. It can be destroyed and injected into the ground.

  Furthermore, if a sheet material made of water-soluble polyvinyl alcohol or carboxin methylcellulose is used as a covering material, not only can the seal grout be prevented from entering when the injection tube is inserted into the drilling hole, Since it melts at the time of injection of the next injection material, injection of the secondary injection material is not hindered. It is also possible to use a weak vinyl coating film material that can be easily broken by the discharge pressure of the injection material.

  The injection tube device according to claim 3 is the injection tube device according to claim 1 or 2, wherein a packer is provided on the outer injection tube.

  The present invention fills the gap between the hole wall, the injection outer pipe and the columnar space water conveyance member with a seal grout, and further partitions the gap between the hole wall and the injection outer pipe into a plurality of layers in the tube axis direction by the outer pipe packer. The primary injection material and the secondary injection material can be prevented from escaping to other stages, and the primary injection material and the secondary injection material can be reliably infiltrated into the formation of the specific injection stage, respectively (see FIG. 15 (a) and (b)). The intervals between the outer tube packers may be narrowed, and a grout with a short gelation time or a suspended grout may be roughly packed and injected between the packers as a primary injection material.

  The outer tube packer may be formed of a bag body, a rubber tube, or the like, and may be any one that expands to a diameter larger than the inner diameter of the drilled hole by filling with cementitious solidifying material or chemical solution from the ground.

  Further, the outer tube packer expands and closes the gap between the hole wall and the injection outer tube on both the upper and lower sides of each columnar space water guide member, so that a plurality of gaps between the hole wall and the injection outer tube are formed in the tube axis direction. Anything that can be partitioned is acceptable. In addition, what is necessary is just to attach an outer pipe | tube packer to the up-and-down both sides of a columnar space water conveyance member, or any one side.

  In addition, the outer tube packer is formed in two stages, from which a quick-setting grout or suspension type grout is injected, and then a coarse soil layer or a soft soil layer to which the injected material is easy to escape, and then the columnar space. Osmotic grout may be injected from the water guiding member.

  According to the present invention, the gap between the hole wall and the outer injection tube is filled with the seal grout, and further, the gap between the hole wall and the outer injection tube is divided into a plurality of layers to close the other parts of the injection material. The escape to the stage can be reliably prevented, and the primary injection material and the secondary injection material can be reliably injected into the formation of the specific injection stage.

  The injection tube device according to claim 4 is provided with a plurality of injection tube devices according to any one of claims 1 to 3, which are disposed at a plurality of injection points, a storage tank for injection material, and an independent drive source. A plurality of unit pumps for pumping the injection material from the storage tank to the injection pipe device at each injection point by operating at a flow rate pressure detector for detecting the flow rate and / or pressure of the injection material at each injection point; A valve for starting and shutting off the pumping of the injection material, a rotation speed irregularity machine of each unit pump, and a centralized monitoring device for monitoring and controlling the unit pump, the flow pressure detector, the valve and the rotation speed fluctuation machine. It is characterized by.

  The present invention is based on the flow rate and / or pressure data signal of the injection material at each injection point transmitted from the flow rate pressure detector to the centralized monitoring device. By pumping at an injection speed, a discharge pressure, and an injection amount, an injection material is injected into a plurality of injection points simultaneously or selectively to enable primary injection and secondary injection at the plurality of injection points. .

  It is also possible to install an injection tube lifting / lowering device for raising and lowering the injection inner tube of each injection tube device and an injection stage monitoring device for monitoring the injection stage of the injection inner tube (see FIG. 17).

  In particular, as an injection inner tube, an injection inner tube provided with a plurality of injection material discharge ports and inner tube packers in the tube axis direction as shown in FIGS. 6B and 11A is used. By raising and lowering the injection inner tube by the injection tube elevating device, the injection material can be injected simultaneously or selectively into a plurality of injection points and simultaneously or selectively into a plurality of formations at each injection point.

  The ground injection method according to claim 5 is the ground injection method by the injection tube device according to any one of claims 1 to 3, wherein the injection outer tube inserted into the drilling hole and the injection inserted into the injection outer tube. By injecting the primary injection material through the inner pipe, it fills the water channel and the rough soil layer in the ground to prevent the secondary injection material from escaping outside the injection range and to the ground surface. It is characterized in that uniform ground improvement is performed by low-pressure injection of the injection material at a high discharge rate.

  According to the present invention, primary injection intended for rough filling and secondary injection intended for ground improvement can be performed very efficiently using the same injection tube apparatus.

  The ground injection method according to claim 6 is the ground injection method by the injection pipe device according to claim 4, wherein the flow rate and / or pressure data of the injection material at each injection point transmitted from the flow rate pressure detector to the centralized monitoring device. Based on the signal, while monitoring the injection status of the injection material at each injection point in a centralized monitoring device, the injection material is pumped to a plurality of injection points, and the injection material is supplied to each injection point simultaneously or selectively. The primary injection and the secondary injection at a plurality of injection points are performed by injecting into the above.

  According to the present invention, a columnar seepage source composed of a columnar space water guiding member is formed in a certain length in the tube axis direction in the gap between the hole wall and the injection outer tube, so that it is large from the hole wall to the surrounding ground. A low-volume injection can be performed without discharging a large volume of secondary injection material at a discharge speed by columnar injection.

  Further, since the seal grout is broken for a certain length by the discharge pressure of the injection material, the primary injection material and the secondary injection material can be independently injected into a predetermined injection stage in an optimum amount.

  In addition, the primary injection material breaks the seal grout and is injected into the ground. However, since the columnar space water conveyance member is covered by the presence of the seal grout, the primary injection material discharged into the ground is the columnar space water conveyance member. It never flows back into it.

  For this reason, it is possible to infiltrate between the soil particles without discharging by a low pressure infiltration with a large discharge amount from a large columnar space water conveyance member (columnar infiltration source) for each predetermined injection stage.

  In addition, the secondary injection material injected into the ground through the injection inner pipe passes, but the outer space of the columnar space water guide member is covered with a seal grout coating portion that does not invade the seal grout. The clogging of the water guide member can be prevented and the secondary injection material can be injected smoothly.

  Also, at each injection stage, the check grout, the columnar space water conveyance member, and the check valve that covers the secondary injection material discharge port act to cause the injection material from another injection stage or other injection pipe to flow back into the injection pipe. In addition, since the non-injected columnar space and the injection material discharge port are not blocked by the presence of the seal grout, it is possible to easily perform injection and repeated injection as planned. it can.

  Further, by using the sealing grout invasion preventing covering member, it is possible to prevent the columnar space water guiding member from entering even if a suspension grout having a small particle size is used as the primary injection material. By roughening the eyes, ground injection can be performed without clogging even if a suspension grout is used as the secondary injection material.

1 shows an embodiment of an injection tube device, FIG. 1 (a) is a front view of an injection outer tube and an injection inner tube installed in a drilling hole, and FIG. 2 (b) and FIG. -It is a Y line and a roll line expanded sectional view. The tip of the injection outer tube installed in the drilling hole is shown. FIG. (A) is a partially enlarged longitudinal sectional view, and FIG. (B) is a part having a seal grout invasion prevention covering member covering the columnar space water conveyance member. It is an enlarged vertical sectional view. FIG. 1 shows the injection tube device shown in FIG. 1, where FIG. 1 (a) is a front view of the injection inner tube, and FIG. 1 (b) is a part of the tip of the injection outer tube showing the state where the injection inner tube is inserted into the injection outer tube. It is an enlarged vertical sectional view. Another embodiment of the injection tube apparatus is shown, in which FIG. (A) is a front view of the outside and inside of the injection tube installed in the drilling hole, and FIGS. (B) and (c) are respectively the drawings in FIG. FIG. 4 is an enlarged cross-sectional view of line C and knee line. The tip of the injection outer tube installed in the drilling hole is shown. FIG. (A) is a partially enlarged longitudinal sectional view, and FIG. (B) is a part having a seal grout invasion prevention covering member covering the columnar space water conveyance member. It is an enlarged vertical sectional view. FIGS. 4A and 4B are side views of the injection inner tube, and FIG. 2C is a partially enlarged longitudinal sectional view of the distal end portion of the injection outer tube showing a state where the injection inner tube is inserted into the injection outer tube. Drawing (a)-(c) is a sectional view showing the construction procedure which installs an injection outer pipe in the ground. It is sectional drawing which shows the injection method of the injection material by the injection tube apparatus shown in FIG. It is sectional drawing which shows the injection method of the injection material by the injection tube apparatus shown in FIG. Fig. 4 shows another embodiment of the injection tube device, where Fig. (A) is a front view of the injection outer tube and the injection inner tube installed in the drilling hole, and Fig. (B) is a partially enlarged longitudinal section of an intermediate portion of the injection outer tube. The surface views and FIGS. (C) and (d) are sectional views taken along the lines H-H and H-H, respectively, in FIG. FIG. 1A is a front view of the injection inner tube, and FIG. 2B is a partially enlarged longitudinal sectional view of an intermediate portion of the injection outer tube showing a state in which the injection inner tube is inserted into the injection outer tube. Fig. 4 shows another embodiment of the injection tube device, where Fig. (A) is a front view of the injection outer tube and the injection inner tube installed in the drilling hole, and Fig. (B) is a partially enlarged longitudinal section of an intermediate portion of the injection outer tube. A plane view and FIGS. (C) and (d) are sectional views of the tote line and the teach line in FIG. (B), respectively. It is a partially expanded longitudinal cross-sectional view of the intermediate part of the injection outer tube showing a state where the injection inner tube is inserted into the injection outer tube. The other embodiment of an injection tube device is shown, a figure (a) is a front view of an injection outer pipe installed in a drilling hole, and figures (b) and (c) are each a reel line in figure (a), The Nuno line enlarged sectional view, FIG. 4D is an enlarged sectional view of the slit portion of the seal grout intrusion prevention covering member. The ground injection method using the injection pipe device is shown. FIG. (A) shows the ground injection method using the injection pipe device without the seal grout intrusion prevention coating member. FIG. (B) shows the injection with the seal grout penetration prevention coating member. It is sectional drawing which shows the ground injection construction method by a pipe apparatus. FIG. 5 is a schematic diagram of an injection tube apparatus configured to allow injection material to be injected into a plurality of injection stages at a plurality of points simultaneously or selectively, showing another embodiment of the injection tube apparatus. FIG. 5 is a schematic diagram of an injection tube device that is another embodiment of the injection tube device and configured to be able to inject an injection material simultaneously or selectively into the ground of a plurality of injection stages. FIG. 5 is a schematic diagram of an injection tube device that is another embodiment of the injection tube device and configured to be able to inject an injection material simultaneously or selectively into the ground of a plurality of injection stages. It is sectional drawing which shows an example of the conventional injection tube apparatus. It is sectional drawing which shows an example of the conventional injection tube apparatus. It is sectional drawing which shows an example of the conventional injection tube apparatus. Drawing (a)-(e) is an explanatory view showing the principle of an injection construction method. Figures (a) and (b) are explanatory views showing the principle of the injection method.

  1 to 3 show an embodiment of an injection tube device according to the present invention. In the figure, an injection outer tube 2 is inserted into the bore 1 and an injection inner tube 3 is inserted into the injection outer tube 2. Further, a seal grout 4 is filled in the gap between the drilling hole 1 and the injection outer tube 2.

  The seal grout 4 is solidified in the hole 1 so as to hold the injection outer tube 2 in the hole 1 and prevent the hole wall from collapsing, and the injected material injected into the hole 1 is made of the hole wall. It functions to prevent escape in the gap between the outer pipe 2 and the outer pipe 2 in the direction of the pipe axis of the outer pipe 2 and is filled in the entire length of the hole 1 or the ground improvement zone. .

  The seal grout 4 is made of low-strength cement mortar, bentonite, low-alkaline cement, lime, gypsum, or the like that can be easily crushed by the discharge pressure of the injection material even when solidified.

  For the outer injection pipe 2 and the inner injection pipe 3, a steel pipe, a hard PVC pipe, a biodegradable injection pipe or the like is used. Further, the tip of the outer injection tube 2 is closed, and a primary injection material discharge port 2a is formed in the side wall portion of the tip, and a secondary injection material discharge port 2b is provided below the injection material discharge port 2b in the tube axis direction of the injection outer tube 2. It is formed at a predetermined interval.

  A check valve 5 is attached to each of the primary injection material discharge port 2a and the secondary injection material discharge port 2b, and in the tube axis direction within a predetermined range L of the upper surface of the secondary injection material discharge port 2b and its upper and lower sides. A column-shaped space water guiding member 6 that is continuous with the cylinder is attached.

  The primary injection material is injected for the purpose of homogenizing the ground by filling (roughly filling) voids and water in the ground around the borehole 1 and mainly cement bentonite and instantaneous setting type injection material. Is done. In addition, the secondary injection material is injected for the original purpose of injection such as water stop, strengthening, compaction, and liquefaction prevention of the ground, and mainly a loose-type injection material is injected.

  The check valve 5 is a valve for preventing the backflow of the primary injection material and the secondary injection material discharged from the primary injection material discharge port 2a and the secondary injection material discharge port 2b to the periphery of the drilling hole 1, respectively. It is mainly formed from a rubber sleeve or the like.

  The columnar space infiltration member 6 forms a columnar infiltration source for injecting and injecting as much secondary injection material discharged from the secondary injection material discharge port 2b as possible into a wide range of ground even under low pressure. The columnar space water conveyance member 6 has a predetermined thickness from a net-like body having water permeability, a woven fabric, a non-woven fabric, a synthetic resin film material or a strip-shaped synthetic resin material having slits or a large number of small holes, or various drain materials. It is formed in the shape of a cylinder or a belt having a thickness.

  Further, the columnar space water guide member 6 covers the outer periphery of the injection outer tube 2 including the upper surface of the secondary injection material discharge port 2b at the tip of the injection outer tube 2 so as to cover a certain section L in the tube axis direction of the injection outer tube 2. It is attached.

  Furthermore, the length L of the columnar space water conveyance member 6 is adjusted according to the condition of the ground. For example, the length L of the columnar space water conveyance member 6 for a low water permeability layer such as a clay layer or a silt layer. By increasing the length, that is, by increasing the length L of the columnar permeation source, a large volume of secondary injection material can be injected over a wide range even under a low pressure. Moreover, when it is desired to obtain a large consolidated diameter, the length L of the columnar space water guide member 6, that is, the length L of the columnar permeation source may be increased, and the interval between the drill holes 1 may be increased.

In any case, the columnar space water guide member 6 is mounted so as to cover the check valve 5 which covers the secondary injection material discharge port 2b, also do Material itself has a water permeability, material itself Even if it is impermeable, it is formed with water permeability by having gaps, slits, or perforations.

  FIG. 2 (b) shows an injection tube device in which a sheet-like seal grout intrusion prevention covering member 7 is attached on the columnar space water guiding member 6.

  The seal grout intrusion prevention covering member 7 prevents the primary injection material discharged from the primary injection material discharge port 2a around the injection outer tube 2 and the seal grout 4 before solidification from entering the columnar space water guide member 6. The primary injection material and the seal grout 4 are not passed, but the secondary injection material is formed of a material or structure that allows it to pass.

  In this case, the seal grout intrusion prevention covering member 7 is, for example, a rubber sheet having slits and many small holes, or a thin vinyl sheet that can be easily broken by the discharge pressure of the injection material, or a mesh-like rubber sheet or injection material. It is formed of a perforated vinyl sheet or the like that can be easily broken by the discharge pressure.

  The distal end of the injection inner tube 3 is closed, and an injection material discharge port 3a is formed in a side wall portion of the distal end. A pair of packers 3b and 3b are attached to both upper and lower sides of the injection material discharge port 3a. It has been.

  The packer 3b is formed from a rubber bag or the like, and is expanded in the gap between the outer injection tube 2 and the inner injection tube 3 by injecting air or fluid. The gap with the tube 3 can be sealed at both the upper and lower sides of the injection material discharge port 3a.

  In such a configuration, the injection inner tube 3 is set in the injection outer tube 2 so that the injection material discharge port 3 a coincides with the primary injection material discharge hole 2 a of the injection outer tube 2.

  Next, air or the like is enclosed in the packers 3b and 3b from the ground to expand the packers 3b and 3b, so that the injection outer tube 2 and the injection outer tube 2 are inserted into the gap between the injection outer tube 2 and the injection inner tube 3. An injection material flow path communicating with the primary injection material discharge hole 2a is formed (see FIG. 3B).

  Then, when the primary injection material is injected into the injection inner tube 3, the primary injection material pushes the check valve 5 open by the discharge pressure, and is discharged out of the injection outer tube 2 from the primary injection material discharge port 2a. It is infused into the ground. Thereby, rough filling can be performed on the ground around the hole 1.

  In this case, since the columnar space water guide member 6 as the columnar penetration source is covered with the sheet-like seal grout intrusion covering member 7, it was discharged around the hole 1 during and after the injection of the primary injection material. The primary injection material does not enter the columnar space water guiding member 6 and deteriorate the function as the columnar penetration source.

  Further, the gap between the hole wall of the drilling hole 1 and the outer injection tube 2 is filled with the seal grout 4 over the entire length or the range of a predetermined injection depth, so that the primary injection material is displaced in the tube axis direction. I do not send it.

  Next, the injection inner tube 3 is set in the injection outer tube 2 so that the injection material discharge port 3 a of the injection inner tube 3 coincides with the secondary injection material discharge hole 2 b of the injection outer tube 2. Next, the packers 3 b and 3 b are expanded to form an injection material flow path communicating with the columnar space water guide member (columnar permeation source) 6 from the injection inner tube 3 in the gap between the injection outer tube 2 and the injection inner tube 3.

  Then, when the secondary injection material is injected into the injection inner pipe 3, the secondary injection material is discharged from the injection material discharge port 3a into the columnar space water conveyance member (columnar penetration source) 6, and a predetermined amount of the columnar space water conveyance member 6 is set. After flowing into the space of the length, the seal grout 4 is broken, and infiltrated (infiltrated between soil particles) from the columnar infiltration source 6 into the ground around the hole wall.

  In this case, since the ground around the drilling hole 1 is coarsely packed in advance by primary injection, the secondary injection material will not be wasted into the ground.

  Further, the gap between the hole wall of the hole 1 and the injection outer tube 2 is filled with the seal grout 4 in the entire length or the range of a predetermined injection depth, so that the secondary injection material is aligned in the tube axis direction. The injection material may flow into the columnar space water guide member (columnar permeation source) 6 adjacent in the axial direction of the injection outer tube 2 or into another adjacent injection outer tube 2 without escape. Absent.

  An outer tube packer (not shown) for vertically partitioning the gap between the hole wall and the injection outer tube 2 is attached to the upper side of the check valve 5 for preventing the back flow of the injection material at the primary injection material discharge port 2a. By expanding the tube packer and partitioning the gap between the hole wall and the outer injection tube 2 up and down in advance on the upper side of the check valve 5, the primary injection material and the secondary injection material can escape upward in the gap. It can be surely prevented.

  4 to 6 show other embodiments of the present invention. In particular, the primary injection material discharge port 2a is formed at a position above the injection outer tube 2, and is positioned below the position of the primary injection material discharge port 2a. The secondary injection material discharge port 2b is formed.

  A check valve 5 is attached to each of the primary injection material discharge port 2a and the secondary injection material discharge port 2b, and the columnar space water conveyance member 6 is provided in a certain range L in the tube axis direction including the upper surface of each secondary injection material discharge port 2b. Are attached by being wound in a ring or spiral.

  In FIG. 5B, a sheet-like seal grout intrusion prevention covering member 7 is attached along the columnar space water conveyance member 6 on the columnar space water conveyance member 6.

  In addition, as shown in FIG. 6B, the injection inner tube 3 has a plurality of injection material discharge ports 3a formed at predetermined intervals in the side wall of the tip, and each injection material discharge port 3a. A pair of packers 3b, 3b are respectively attached to the upper and lower sides of the frame. The injection material discharge port 3 a is formed at a position substantially coincident with the secondary injection material discharge port 2 b of the injection outer tube 2.

  By using this injection inner pipe 3, the secondary injection material can be injected over a wide range extremely efficiently. Further, when the injection material is discharged from the secondary injection material discharge port 2b covered by the check valve 5 using an injection inner tube having only one secondary injection material discharge port 2b, the injection material is a columnar shape having a predetermined length L. It flows into the space water guide member 6 and breaks the seal grout 4 to penetrate into the surrounding ground in a columnar shape.

  5B and 6C show a state in which the section of the length L of the columnar space water guide member 6 is covered with the seal grout intrusion prevention covering member 7. FIG.

  7 (a) to 7 (c) show a method of installing the outer injection pipe 2 of the injection pipe apparatus shown in FIG. 1 in the ground, and first, the hole 1 is formed using the casing a and the excavator b. To do.

  Next, the injection outer tube 2 is built in the casing a of the drilling hole 1. Then, the casing a is gradually pulled out while the seal grout 4 is filled in the casing a of the drilling hole 1. The injection outer tube 2 can be built in the hole 1 by the above procedure.

  FIG. 8 shows a ground injection method using the injection pipe device shown in FIG. 1, and as shown in the figure, the plurality of injection outer pipes 2 are arranged in the ground at different intervals with different insertion depths.

  By injecting the ground under such an arrangement, a large-diameter consolidated body corresponding to the length L can be efficiently formed in the ground, and at the same time or selected at a plurality of points. Therefore, ground improvement can be performed in a short period of time and efficiently.

  In addition, by increasing the length L of the columnar space water conveyance member (columnar permeation source) 6 deeply (longer), low pressure injection is possible even when the amount of injection material discharged is increased, and the drilling interval D is increased. Therefore, it is possible to form a large consolidated body and effectively and economically perform a wide range of ground improvement, which is particularly suitable for liquefaction countermeasures.

  In particular, in the performance design of the recent liquefaction method, it is possible to obtain economic efficiency by leaving an unconsolidated portion as shown in the figure without completely consolidating a liquefiable layer. For this purpose, it is desirable to inject a silica solution in a weakly alkaline, neutral or acidic region (pH 1 to 10) having a long gel time and excellent durability.

  Such a grout can be a silica sol grout obtained by neutralizing an alkali of water glass with an acid, a silica grout obtained by treating water glass with an ion exchange resin or an ion exchange membrane, or a mixture thereof.

  FIG. 9 shows a ground injection method using the injection pipe device shown in FIG. 1 as well. As shown in the figure, a plurality of injection pipes are arranged at different depths in one hole 1.

  Further, a seal grout 4 is filled in the gap between the hole wall of the hole 1 and the injection outer tube 2 of each device over the entire length of the hole 1.

  With such an arrangement, a plurality of columnar space water guide members (columnar permeation sources) 6 that are continuous in a certain section L in the tube axis direction are formed in the bore 1 at predetermined intervals in the tube axis direction. Then, the primary injection material and the secondary injection material are injected into the plurality of injection stages A, B, C, and D by injecting the injection material into the plurality of injection outer tubes 2 through the injection inner tube 3, respectively. Can do.

  FIGS. 10 and 11 also show another embodiment of the injection tube device of the present invention. In particular, the primary injection material discharge port 2a and the secondary injection material discharge port 2b of the injection outer tube 2 are respectively connected to the injection outer tube 2. A plurality of them are alternately formed at regular intervals in the tube axis direction.

  The check valve 5 is attached to each of the injection material discharge ports 2a and 2b, and the columnar space water guide member 6 passes through the fixed sections L on both the upper and lower sides including the upper surface of each secondary injection material discharge port 2b in the tube axis direction. Are attached at regular intervals in the tube axis direction of the outer injection tube 2, and a seal grout intrusion preventing clothing member 7 is further attached on the columnar space water guide member (columnar penetration source) 6.

  By being configured in this way, a plurality of columnar permeation sources that are continuous in a certain section L in the tube axis direction are formed at regular intervals in the tube axis direction in the gap between the hole wall of the drilling hole 1 and the outer injection tube 2. Is done.

  Then, by injecting the primary injection material and the secondary injection material into the injection outer tube 2 through the injection inner tube 3, respectively, the primary injection material and the secondary injection are injected into the plurality of injection stages A, B, C, D. Each material can be injected.

  FIGS. 12 and 13 similarly show another embodiment of the injection tube device of the present invention. In FIG. 12, the primary injection material discharge port 2 a in particular in the injection outer tube 2 is connected to the side wall of the injection outer tube 2. A plurality of secondary injection material discharge ports 2b are formed at regular intervals in the axial direction, and a plurality of secondary injection material discharge ports 2b are formed at regular intervals between the primary injection material discharge ports 2a and 2a.

  The check valves 5 are respectively attached to the primary injection material discharge ports 2 a and the secondary injection material discharge ports 2 b, and the columnar space water guide members 6 are respectively connected to the secondary injection material discharge ports 2 b covered by the check valve 5. A plurality of pipes are attached so as to cover a certain section L on both the upper and lower sides including the upper surface of the pipe and in the pipe axial direction of the injection outer pipe 2 in a ring shape or a spiral shape. A seal grout intrusion-preventing covering member 7 is attached.

  By being configured in this way, a plurality of independent columnar penetration sources covered with a seal grout having a fixed length L in the tube axis direction in the gap between the hole wall of the drilling hole 1 and the injection outer tube 2 can be It is formed at regular intervals in the direction.

  Further, by injecting the injection material into the injection outer tube 2 through the injection inner tube 3, the secondary injection material is injected into the plurality of injection stages A, B, C, and D with the primary injection material. Osmotic injection can be performed.

  14 (a), (b), (c), and (d) show another embodiment of the injection pipe device of the present invention, and in particular, the primary injection material discharge port 2a of the injection outer pipe 2 has an external injection side. A plurality of secondary injection material discharge ports 2b are formed at regular intervals in the tube axis direction on the side wall portion of the tube 2, and a plurality of secondary injection material discharge ports 2a are formed at regular intervals between the primary injection material discharge ports 2a and 2a.

  The columnar space water guide member 6 is formed to have a length that covers a certain length L on both the upper and lower sides including the upper surface of the secondary injection material discharge port 2b covered by the plurality of check valves 5, and each secondary injection material It is attached so as to cover the discharge port 2b, and its upper and lower ends are fixed in close contact with the injection outer tube 2.

  The seal grout intrusion prevention covering member 7 is attached so as to cover each columnar space water guiding member 6. Further, the seal grout intrusion prevention covering member 7 is made of a sheet material made of a water-permeable woven fabric, a resin sheet material having small holes or slits, or a number of perforations that can be easily broken by discharge pressure in the vertical direction. It is formed in a bag shape or tube shape that is continuous or independent from the thin film sealing material in the tube axis direction.

  In particular, the slits and small holes formed in the latter sheet material are opened by the discharge pressure of the secondary injection material discharged from the inside to the outside of the injection outer tube, but the primary injection material and the seal flowing back into the injection outer tube A fin-like check valve 7a is formed so as to close depending on the inflow of grout or the like (see FIG. 14D).

  In particular, as shown in FIGS. 15A and 15B, in the embodiment shown in FIGS. 10 to 14, the gap between the hole wall and the injection outer tube 2 is increased and decreased in the outer portion of the injection outer tube 2. The outer tube packer 18 is partitioned at predetermined intervals in the tube axis direction, the outer tube packer 18 is expanded, and the gap between the hole wall and the injection outer tube 2 is divided into a plurality of layers in the tube axis direction in advance. By sealing, it is possible to prevent the primary injection material and the secondary injection material from being transferred to the other injection stages in the gap.

  In this case, the outer tube packer 18 includes the columnar space water guiding member (columnar permeation source) 6 and / or the primary injection material discharge port 2a adjacent to each other in the tube axis direction of the injection outer tube 2 one or more in the tube axis direction. It is attached at regular intervals in the tube axis direction so as to partition. The outer tube packer 18 is formed by filling a bag or the like with a solidifying material such as mortar from the ground via an injection tube.

  Further, the seal grout 4 is filled in the gap between the hole wall and the columnar space water conveyance member 6, and in the embodiment illustrated in FIG. 15B, the outer periphery of each columnar space water conveyance member 6 is further provided with a seal grout intrusion prevention coating. A member 7 is attached.

  FIGS. 16 to 18 show an injection tube device configured to be able to inject injection material simultaneously or selectively into a plurality of injection points.

  In FIG. 16, holes 1 are formed at a plurality of injection points, and an injection outer tube 2 of the injection tube device shown in FIGS. 1 (a) and 1 (b) is inserted into each hole 1.

  An injection material storage tank 8 in which an injection material is stored is connected to the injection tube of each injection tube device via a conduit 9, and the injection material is supplied from the injection material storage tank 8 to each injection tube device to each conduit 9. A unit pump 10 for pumping, a flow rate pressure detector 11 for detecting the flow rate and pressure of the injected material at each injection point, and a valve 12 for starting and blocking the pumping of the injected material are connected.

  Each unit pump 10 includes a rotational speed transmission 13 such as an inverter, and is configured to operate individually by an independent drive source 14 such as a motor. Further, each unit pump 10, the rotational speed transmission 13, the flow rate pressure detector 11 and the valve 12 are respectively connected to the centralized monitoring device 15, and are all monitored by the centralized monitoring device 15 and controlled individually. Yes.

  In such a configuration, when a flow rate / and / or pressure data signal from the flow rate pressure detector 11 is transmitted to the centralized monitoring device 15, each unit pump 10 is supplied from the storage tank 8 to the injection outer pipe 2 of each device. By the operation, the primary injection material and the secondary injection material are pumped to each injection pipe device at an arbitrary injection speed, discharge pressure, and injection amount.

  At that time, in particular, the secondary injection material is simultaneously or selectively discharged from the injection material discharge port 2a of each device to the columnar space water conveyance member (columnar penetration source) 6 at a plurality of injection points, and the columnar space water conveyance member (columnar shape). The permeation source 6) is injected into the surrounding ground simultaneously or selectively.

  FIG. 17 is configured so that the primary injection material and the secondary injection material can be simultaneously or selectively injected into a plurality of injection stages A, B, C, and D at a plurality of injection points in the embodiment of FIG. This shows an injection tube apparatus.

  A plurality of outer injection pipes of the injection pipe apparatus shown in FIG. 1 or FIG. 2 are inserted into each hole 1 formed at a plurality of injection points as shown in FIG. That is, the depth of the injection outer tube 2 of each injection tube device is different, and the columnar space water guide members (columnar penetration source) 6 of each injection outer tube 2 are positioned at predetermined intervals in the depth direction of the drilling hole 1. Is arranged. Other configurations are substantially the same as those of the embodiment shown in FIG.

  Then, by injecting the primary injection material and the secondary injection material into the injection outer pipe at each injection point, respectively, the primary injection material and the secondary injection material are ground into the ground of the plurality of injection stages A, B, C, D at the plurality of injection points. The next injection materials can be injected simultaneously or selectively.

  18, in the embodiment of FIGS. 10, 12, and 14, the primary injection material and the secondary injection material can be injected simultaneously or selectively into the ground of the injection stages A, B, C, and D at a plurality of injection points, respectively. An injection tube apparatus configured as described above is shown.

  In the figure, the injection outer tube of the injection tube device shown in FIG. 10, 12 or FIG. 14 is inserted into each hole 1 formed at a plurality of injection points. Also, an injection inner tube lifting device 16 for changing the injection stage by moving the injection inner tube 3 of each device up and down and an injection stage monitoring device 17 for monitoring the injection stage of the injection inner tube 3 are installed.

  Other configurations are almost the same as those of the embodiment shown in FIGS. Further, the injection material storage tank 8, the conduit 9, the unit pump 10, the flow rate pressure detector 11, and the like are substantially the same as the embodiment shown in FIGS.

  In such a configuration, when a flow rate / and / or pressure data signal from the flow rate pressure detector 11 is transmitted to the centralized monitoring device 15, the injection material in the storage tank 8 is arbitrarily changed by the operation of each unit pump 10. It is pumped to the injection inner tube 3 of each device at the injection speed, discharge pressure and injection amount.

  In particular, the secondary injection material is discharged from the plurality of injection material discharge ports 2b of each injection outer tube 2 into the plurality of columnar space water guiding members (columnar permeation sources) 6 at each of the plurality of injection points. In this case, the permeation is carried out simultaneously or selectively from the columnar penetration source into the surrounding ground.

  Further, the injection inner tube 3 at each injection point is operated by the injection inner tube lifting / lowering device 16 in accordance with an instruction from the centralized monitoring device 15, so that the injection inner tube 3 rises in the outer injection tube 2, The primary injection material and the secondary injection material can be respectively injected into the ground of each of the injection stages A, B, C, and D at a plurality of injection points.

  In the embodiment shown in FIGS. 16 to 18, the unit pumps 10 usually constitute 5 to 100 units as a multi-injection infusion device, and these unit pumps 10 are arranged horizontally, vertically or three-dimensionally in one set. Can be arranged as

  Each unit pump 10 can be operated by a drive source 14 such as a motor. Further, each drive source 14 can be operated by a rotational speed transmission 13 such as an inverter controlled by a central monitoring device 15. Therefore, according to this embodiment, it is possible to configure as a single united infusion device which is composed of a large number of unit pumps 10 and has a small capacity as a whole and is compact.

  For this reason, when a plunger pump is used as the unit pump 10 in one set of multiple connecting devices, the discharge rate is 1 to 30 liters / min at 50 Hz, and for example when 10 units are used, the inverter is instructed by the centralized monitoring device 17. Thus, while maintaining the optimal injection speed and discharge pressure at a predetermined injection point, the entire injection amount from a large number of discharge ports (for example, 50 discharge ports) is controlled by the centralized monitoring device 15 so that the total discharge amount is (1 to 1). 30) × 10 = 5 to 300 liters / minute is collectively managed, enabling low-pressure, low particle discharge and interparticle penetration, and shortening the construction period by rapid construction.

  In the present invention, a columnar infiltration source is individually formed on a plurality of injection stages at a plurality of injection points, and an injection material can be sequentially or simultaneously injected into the ground from each columnar infiltration source. An injection pipe device suitable for liquefaction prevention injection works that can infiltrate between soil particles at a low pressure even at an injection speed, can obtain a larger consolidated diameter, and requires economical ground improvement of large-capacity soil. provide.

DESCRIPTION OF SYMBOLS 1 Drilling hole 2 Injection outer tube 2a Primary injection material discharge port 2b Secondary injection material discharge port 3 Injection inner tube 3a Injection material discharge port 3b Packer 4 Seal grout 5 Check valve 6 Column-shaped space water guide member 7 Seal grout invasion prevention coating member 8 Injection material storage tank 9 Conduit 10 Unit pump 11 Flow rate pressure detector 12 Valve 13 Rotational speed transmission 14 Drive source 15 Concentration monitoring device 16 Injection inner pipe lifting device 17 Concentration monitoring device 18 Outer tube packer

Claims (6)

  In an injection tube device comprising an injection outer tube installed in a drilling hole and an injection inner tube installed in the injection outer tube, the injection outer tube is provided at intervals in the tube axis direction. A predetermined range in the axial direction of the tube including the primary injection material discharge port and the secondary injection material discharge port, a check valve for preventing backflow from these injection material discharge ports, and the upper surface of the secondary injection material discharge port is spaced apart. An injection pipe device comprising: a columnar space water-conducting member that covers the wall and a seal grout filled in a gap between the hole wall of the drilling hole, the injection outer pipe, and the columnar space water-conduction member.   The injection pipe device according to claim 1, further comprising a seal grout intrusion prevention covering member that covers the columnar space water conveyance member, wherein the seal grout intrusion prevention covering member is a secondary injecting material that is injected into the ground through the injection inner pipe. An injection tube device characterized by being configured to pass through.   3. The injection tube device according to claim 1, further comprising a packer for partitioning a gap between the hole wall and the injection outer tube at a side portion of the injection outer tube. A plurality of injection pipe devices according to any one of claims 1 to 3, arranged at a plurality of injection points, a storage tank for injection material, and each of the storage tanks operated by independent drive sources. A plurality of unit pumps for pumping the injection material to the injection pipe device, a flow rate pressure detector for detecting the flow rate and / or pressure of the injection material at each injection point, and a valve for starting and shutting off the pumping of the injection material, An injection pipe device comprising: a rotation number irregularity machine for each unit pump; and a centralized monitoring device for monitoring and controlling the unit pump, flow rate pressure detector, valve and rotation number irregularity machine.   In the ground injection method by the injection tube device according to any one of claims 1 to 3, the primary injection material is injected through the injection outer tube inserted into the drilling hole and the injection inner tube inserted into the injection outer tube. By filling the ground and rough soil layer in the ground, the secondary injection material is prevented from escaping outside the injection range or to the ground surface, and then the secondary injection material is injected at low pressure at a high discharge rate. A ground injection method characterized in that even ground improvement is performed.   5. The ground injection method using the injection pipe device according to claim 4, wherein the injection at each injection point is based on a flow rate and / or pressure data signal at each injection point transmitted from the flow pressure detector to the central monitoring device. Primary monitoring at multiple injection points by pumping injection material to multiple injection points and simultaneously or selectively injecting injection material to each injection point while monitoring the injection status of the material at once with a centralized monitoring device A ground injection method characterized by performing injection and secondary injection.

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