JP3790232B2 - Packer and the ground reinforcement method using it - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a packer used for reinforcing a natural ground by injecting a solidified material such as cement milk or mortar into a long bore hole drilled in a rock, for example, and a natural ground reinforcing method using the same. .
[0002]
[Prior art]
Conventionally, for example, in so-called long tip receiving work or pipe roofs for tunnel excavation, a long bore hole is usually drilled in the preceding ground to be excavated for 10 m or more, and solidified in the bore hole and its surrounding ground. It is practiced to improve and reinforce natural ground by injecting materials.
[0003]
In this way, when the area where the binder is to be injected is long, if the binder is injected all over the entire length of the area, some of the binder may be cracked depending on the nature of the ground and the geology. Leakage may occur, and the consolidated material may not be injected uniformly over the entire length of the borehole.
[0004]
Therefore, it has been proposed to provide a packer in the bore hole, partition the inside and outside of the bore hole into a plurality of regions, and inject a caking material into each of the regions. Proposed the use of a dumbbell-shaped packer as in Patent Document 1 below. The dumbbell-shaped packer not only partitions the borehole or the reinforcing pipe such as a steel pipe installed in the borehole, but also partitions the surrounding ground and injects the consolidated material into each partitioned ground. It is an object.
[0005]
However, when a foamable resin such as urethane is used as the expansion-consolidating material, the packer is made of a liquid-permeable material after both ends first swell due to the foaming of the resin and come into close contact with the inner surface of the borehole. It can gradually ooze out from the center to form a good partition on the ground to be poured. For example, as the above-mentioned solidification material, non-foamed solidification material, especially cement milk and mortar When cement-based consolidated materials such as the above are used, before the both ends of the dumbbell-shaped packer are fully expanded, the consolidated material flows out from the central portion and the function as a packer is not fully exhibited, and the partitioning is performed well. There was a possibility that it could not be formed.
[0006]
[Patent Document 1]
Japanese Patent No. 2785907 [0007]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above-described problems, and even when a non-foamable consolidated material, particularly a cement-based consolidated material, is used as a packed material for expanding a packer, the function as a packer is excellent. It is an object of the present invention to provide a packer that can be exhibited and can well inject a consolidated material over the entire length of a long borehole, and a ground reinforcement method using the packer.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a packer according to the present invention and a ground reinforcement method using the same are configured as follows.
[0009]
That is, the packer according to the present invention is a packer that partitions the inside and outside of the borehole into a plurality of regions in the longitudinal direction by injecting cement-based caking material into the inside, and is provided by being inserted into the borehole or the borehole. A cylindrical body having a diameter smaller than that of the pipe, a bag made of a liquid-impervious material is provided at both ends of the cylindrical body, the cemented caking material is injected, and the bag is expanded and then the packer A check valve mechanism that opens when the internal pressure rises above a predetermined value is provided in the cylinder .
[0010]
Further, the natural ground reinforcement method according to the present invention sets a partition location at a predetermined position in the length direction of the bore hole formed in the natural ground, and the inside of the bore hole corresponding to each partition location or the inside of the reinforcement pipe disposed in the bore hole. The packer according to claim 1 is arranged, a cement-based caking material is injected into the packer, the bags provided at both ends of the cylindrical body of the packer are inflated, and the borehole or the reinforcing tube After being in close contact with the inner surface, subsequently, a cement-based caking material is injected into the packer, the pressure in the packer is increased to a predetermined value or more, and the check valve mechanism is opened to open the caking material in the packer. the said during and discharged into the land Yamauchi surrounding the said cylindrical body and a reinforcing tube or borehole between the bag body to form a partition wall to the partition locations, borehole partitioned by the partition walls and their Wherein the solidified by injecting consolidating material for each natural ground area of the circumference.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the packer and the natural ground reinforcement construction method by this invention are demonstrated concretely based on embodiment shown in a figure.
[0012]
Fig.1 (a) is a longitudinal cross-sectional view which shows one Embodiment of the packer by this invention, The same figure (b) is the bb line cross-sectional view in (a).
[0013]
The packer P of this embodiment is provided with a bag 2 integrally at both ends of a cylinder 1 by adhesion or welding, and a check valve mechanism V provided at the center in the axial direction of the cylinder 1. In this embodiment, the check valve mechanism V includes a through small hole 1a formed in the peripheral wall surface of the cylindrical body 1 and a rubber coated on the outer peripheral surface of the cylindrical body 1 so as to cover the through small hole 1a. And an elastic sleeve 3 made of the same. In the present embodiment, a plurality of the through small holes 1 a are provided in the circumferential direction of the cylindrical body 1, especially three in the case of the drawing, and the through small holes 1 a are covered with one elastic sleeve 3.
[0014]
When the pressure in the packer rises above a predetermined value, the check valve mechanism V pushes the elastic sleeve 3 outwardly in the radial direction of the cylindrical body 1 through the through small hole 1a. 3 and the cylindrical body 1 are configured so that the consolidated material flows out of the cylindrical body 1. Further, the packer P has a bag body 2 at both ends of the cylindrical body that expands to a larger diameter than the cylindrical body 1 as shown in FIG. It is comprised so that the whole may be substantially dumbbell-shaped.
[0015]
The cylinder 1 and the bag 2 constituting the packer P are appropriately made of materials. As the cylinder 1, for example, a synthetic resin tube such as vinyl chloride or a metal tube such as a steel tube can be used. Further, the bag body 2 is a liquid-impervious material that does not permeate or has little permeation of the caking material that expands the packer P, and preferably can be shrunk or folded before being filled with the caking material. By doing so, it is preferable that the diameter can be increased. For example, a hardly liquid-permeable rubber or cloth can be used.
[0016]
In particular, when a cement-based caking material such as cement milk or mortar is used as the caking material, a material made of a hardly water-permeable material that passes only moisture in the caking material but does not pass cement components is used. Is desirable. Specifically, for example, the bag body 2 at both ends of the packer is formed by a waterproof cloth or a resin film that is sewn so that only moisture escapes from the seam, or a material that allows only moisture to permeate the entire bag body, For example, you may form with cloth, textiles, etc., such as bleaching.
[0017]
Further, the intermediate portion between the bag bodies 2 and 2 is formed by the cylinder body 1 having a check valve mechanism that opens at a constant pressure as described above, or a solidified material inside or outside the cylinder body 1. It is also possible to adopt a double structure in which a cloth having a rough texture that passes through or a cloth or a film in which a hole is made in a material that does not allow the binder to pass therethrough is provided.
[0018]
With the above-described configuration, when the packer P is inserted into the borehole and a cement-based consolidated material is injected, the consolidated material is first subjected to moderate dehydration and then passed through a check valve mechanism. When the reinforcing pipe as described later is provided in the bore hole, the liquid is discharged to the outside and flows out into the reinforcing pipe. At that time, the viscosity of the consolidated material decreases due to the dehydrating action, and it flows out from the discharge hole formed in the reinforcing pipe to the outer periphery of the reinforcing pipe, stays there, and seals between the reinforcing pipe and the hole wall. it can.
[0019]
Further, the cylindrical body 1 and the bag body 2 can be integrally formed of a synthetic resin whose former is relatively hard and the latter is soft. In this case, moisture passes through the bag 2 but the cement component is If a hole that does not pass is provided, the above dehydrating action can be provided.
[0020]
Further, the outer diameter and length of the cylindrical body 1 and the bag body 2 are appropriate, but at least the outer diameter dimension of the bag body 2 is a construction method using a reinforcing pipe such as a steel pipe in a state where the binder is filled. In the case of a construction method that does not use the inner surface of the bore hole H, the cylinder 1 is formed to have a size that is sufficiently close to the inner surface of the bore hole H by a predetermined collapse amount or more, and the cylinder 1 is larger than the reinforcing pipe or the bore hole. It is desirable to form it sufficiently small (that is, even if the entire packer P swells, the cylindrical body 1 is in a state of being separated from the inner wall of the reinforcing tube or bore hole).
[0021]
FIG. 2 shows an example of a process for constructing a ground reinforcement method such as a tunnel tip receiving method or a pipe roof method using the above-described packer P. In the figure, H is an upper portion of a portion where a tunnel is to be excavated. In the bore hole H, a reinforcing pipe 4 made of a steel pipe or the like is inserted and arranged.
[0022]
The method for drilling the borehole H and the method for inserting the reinforcing tube 4 are appropriate. For example, the borehole H is sequentially pushed into the borehole H while the borehole is drilled with a drill having a drilling bit at the tip of the rotating shaft. Alternatively, the drill is pulled out, and the drill is pulled out and removed when the hole is drilled to a predetermined depth. Alternatively, after the bore hole is drilled with a drill or the like, the reinforcing tube 4 may be inserted into the bore hole H.
[0023]
Although not shown in the drawing, the reinforcing pipe 4 has a plurality of consolidated material discharge holes formed at substantially equal intervals in the circumferential direction at a plurality of locations in the longitudinal direction. The packer P having the same configuration as that shown in FIG. The packer P is set at a predetermined position in the bore hole H and arranged at that position. In this embodiment, the packer P has a predetermined position at a predetermined position in the reinforcing pipe 4 having a total length of about 12 m. It is the structure which set the partition location in two places in the figure in two places in the space | interval, and accommodated the packer P in each partition location.
[0024]
In FIG. 2, 5 is a packer injection tube for injecting the consolidated material into each packer P, and 6 is a consolidated material in the regions R1 to R3 in the bore holes (reinforcing tubes) partitioned by the packer P. In the main injection pipes for injection, the injection pipes 5 and 6 may be made of resin pipes, steel pipes, or other suitable materials. However, if a pipe having a predetermined strength is used, the natural ground reinforcing effect can be obtained. Can be increased.
[0025]
Each packer P covers the outer periphery of the pipes 5 and 6 so as to cover the end of the packer injection pipe 5 and the peripheral surface of the main injection pipe 6, and the cylindrical body of the bag body 2 of each packer P. 1 is tightly fixed to the peripheral surfaces of the injection pipes 5 and 6 by tightening the end opposite to the band or string not shown in the figure. At that time, the packer P and the injection pipes 5 and 6 If it is assembled in advance and inserted into the reinforcing tube 4, it can be easily loaded. In the figure, 7 is a rubber plug-like seal member that closes the end opening between the reinforcing tube 1 and the bore hole H.
[0026]
In the state where the packer P and the injection pipes 5 and 6 are accommodated in the reinforcing pipe 4 as described above, first, a solidified material such as cement milk is added to each packer P via the packer injection pipe 5. As shown in FIG. 2B, first, the bag body 2 of each packer P swells and comes into close contact with the inner surface of the reinforcing tube 4.
[0027]
Subsequently, when the consolidated material is injected into each packer P and the pressure in each packer P becomes a predetermined value or more, the check valve mechanism opens. In this embodiment, the pressure in each packer The elastic sleeve 3 is pushed up radially outward through the through-hole 1a in FIG. 1, and the cylindrical body 1 and the reinforcing pipe between the elastic sleeve 3 and the cylindrical body 1 between the bag bodies 2 and 2. The caking material flows out between 4 and 4. The consolidated material that has flowed out between the cylindrical body 1 and the reinforcing tube 4 is filled in the reinforcing tube 4 between the bag bodies 2 and 2 and then continuously from a discharge hole (not shown) formed in the reinforcing tube 4. A partition wall W is formed in the borehole H and in the surrounding ground as shown in FIG.
[0028]
After the partition wall W is formed as described above, a caking material is injected into the regions R1 to R3 in the bore holes H partitioned by the packers P through the main injection tube 6, and the inside of each region and the reinforcing tube are injected. It is only necessary to fill the surrounding ground mountain regions corresponding to the regions R1 to R3 through the discharge holes (not shown) formed in 4, respectively, and to inject the consolidation material into the regions R1 to R3. The order is appropriate. As a result, reinforcing regions are formed on both the inner and outer sides of the bore hole H, and the natural ground can be improved and reinforced.
[0029]
As described above, in the present invention, after the bag body 2 at both ends of the packer is sufficiently expanded and is in close contact with the inner surface of the reinforcing tube 4, the check valve mechanism is opened when the pressure in the packer reaches a predetermined value or more. Since the consolidated material flows out between the body 1 and the reinforcing tube 4, the consolidated material that flows out between the cylindrical body 1 and the reinforcing tube 4 flows from between the bag 2 and the reinforcing tube 4. Without leaking, the partition wall W can be satisfactorily formed by reliably injecting a solidified material in a limited manner between the cylinder 1 and the reinforcing pipe 4 and in the surrounding ground.
[0030]
In the above embodiment, the reinforcing pipe 4 such as a steel pipe is provided in the bore hole H. However, as shown in FIG. In such a case, escape of the injected consolidated material is likely to occur, and since it is a construction method that expects ground reinforcement only by injecting the consolidated material without using a reinforcing pipe, the reinforcement effect is expected when the escape occurs. However, even in such a case, the check valve mechanism is opened after the bag body 2 at both end portions of the packer is sufficiently inflated to adhere to the inner surface of the bore hole H, so that the cylindrical body 1 and the bore hole H Therefore, the solidified material that has flowed out between the cylindrical body 1 and the bore hole H forms the partition wall W without leaking from between the bag 2 and the borehole H. It is something that can be done.
[0031]
It is also possible to use a lock bolt, a deformed steel bar or the like instead of the reinforcing tube 4, and in particular, for example, a hollow hole 8a using a hollow lock bolt 8 as shown in FIG. 4 and a bore hole partitioned by a packer. If the through small holes 8b communicating with the inner and outer regions R1 to R3 are formed on the peripheral surface of the lock bolt 8 or the like, the lock bolt 8 can be used in place of the main injection pipe 6. Further, if the through small hole 8b is communicated with the packer, it can be used instead of the packer injection tube 5.
[0032]
Further, the packer of FIG. 1 has a configuration in which the outer peripheral surface of the cylinder 1 is simply covered with the elastic sleeve 3 so as to cover the through small hole 1a formed in the cylinder 1 as a check valve mechanism. As shown in FIG. 5, the slit 3 a may be formed at a position corresponding to the through hole 1 a of the elastic sleeve 3. Also in this case, when the packer bag body 2 is sufficiently inflated and the pressure in the packer exceeds a predetermined value, the consolidated material may flow out from the slit 3a.
[0033]
Further, as shown in FIG. 5, ribs 1 b extending in the axial direction may be formed on the inner peripheral surface of the cylindrical body 1 as necessary, and then the injection tubes 5 and 6 are inserted into the cylindrical body 1. At that time, it is possible to prevent the through-hole 1a from being blocked by these tubes.
[0034]
Further, the check valve mechanism can be appropriately changed in addition to the above. For example, the valve body 10 may be provided on the peripheral surface of the cylinder 1 as shown in FIG. In particular, in the case of the figure, a plurality of ring-shaped valve seats 11 are attached to the peripheral surface of the cylindrical body 1, and substantially frustoconical valve bodies 10 are provided in the respective valve seats 11. As shown in FIG. 6 (b), the mounting portion 10a provided integrally therewith is fixed to the valve seat 11 so that it opens as shown by the chain line in FIG. 6, and the pressure in the packer becomes a predetermined value or more. Sometimes it opens as shown by the chain line. The other configuration is the same as that of FIG. 1, and the same effect as described above can be obtained by providing a check valve mechanism as shown in FIGS.
[0035]
In addition, when only the moisture in the cement-based consolidated material such as bleaching cloth is passed as the bag body 2 of each packer P, but the cement component is difficult to pass, cement-based consolidated in the bag body 2. When the material is injected, moisture in the consolidated material is squeezed out into a kneaded state, so that it can be consolidated more firmly in the bore hole H or the reinforcing tube 4 as well as in the packer P. Thus, the sealing effect and reinforcing effect of the consolidated material can be further improved.
[0036]
For example, in the ground reinforcement method such as tunnel tip receiving construction, after the consolidation material is injected into the packer, the main injection is continuously carried out in the area between the packers, etc., so that it is discharged into and around the packer. It is necessary to harden the consolidated material at an early stage. However, in general, the caking material inserted into the reinforcing tube is limited in size due to the inner diameter of the reinforcing tube, and since it is a disposable member, there is a need to control the cost, so that the caking material is injected into the packer. The diameter of the tube is generally about 10 to 15 mm. Moreover, in order to partition the inside and outside of the reinforcing tube 4 with a packer and perform the subsequent main injection efficiently, a material that hardens as soon as possible must be injected. Therefore, in order to send the consolidated material into the packer without trouble, the fluidity of the consolidated material must be increased.
[0037]
However, if the fluidity of the consolidated material remains high, the length of the reinforcing tube is between the inner wall surface of the borehole and the reinforcing tube 4 where the consolidated material discharged to the outside of the reinforcing tube is not limited to the portion where the partition is to be provided. that can not be able to fulfill the function of forming the partition wall will flow in the direction. However, by providing the packer P with a dehydrating function as described above, it is possible to provide a partition inside and outside the reinforcing pipe using a cement-based caking material, which has been considered difficult until now. For this reason, the consolidated material has good fluidity up to the inside of the packer P, is moderately dehydrated after reaching the inside of the packer P, and increases its viscosity when discharged into the reinforcing pipe or the borehole, so that It stays on the outer periphery of the reinforcing tube and hardens in a short time. That is, when it is dehydrated, the amount of water is lower than that at the time of pouring and can be cured quickly.
[0038]
【The invention's effect】
As described above, since the packer and ground reinforcement method according to the present invention have the above-described configuration, the packer P bag can be used even when a non-foaming cement-based caking material such as cement milk is used as the caking material. When the body 2 swells sufficiently, the consolidated material can be reliably injected into the bore hole H around the cylindrical body 1 and the surrounding natural ground, and the partition wall W can be formed well. In addition, the solidified material can be injected well and surely into the borehole partitioned by the partition wall and the surrounding natural ground, and an effect of providing a natural ground reinforcing method having an excellent reinforcing effect can be provided. is there.
[Brief description of the drawings]
FIG. 1A is a longitudinal sectional view showing an embodiment of a packer according to the present invention.
(B) is the bb line expanded sectional view in (a).
FIGS. 2A to 2C are explanatory views showing an example of a natural ground reinforcement method using the packer.
FIG. 3 is an explanatory diagram showing another example of a natural ground reinforcement method using the packer.
FIG. 4 is an explanatory view showing still another example of the natural ground reinforcement method using the packer.
FIG. 5A is a longitudinal sectional view showing another embodiment of a packer according to the present invention.
(B) is the bb line expanded sectional view in (a).
FIG. 6 (a) is a partially cutaway front view showing still another embodiment of a packer according to the present invention.
(B) is an enlarged vertical sectional view of a part thereof.
(C) is the cc sectional view taken on the line in (b).
[Explanation of symbols]
P Packer 1 Cylindrical body 2 Bag body 3 Elastic sleeve 4 Reinforcement pipes 5 and 6 Solidified material injection pipe H Bore hole

Claims (2)

A packer that divides the inside and outside of the borehole into a plurality of regions in the lengthwise direction by injecting cement-based caking material into the inside, the borehole or a cylinder having a smaller diameter than the reinforcing pipe inserted and disposed in the borehole. has a bag body made of NanToru liquid material to both ends of the cylindrical body provided Rutotomoni, the pressure in the packer after the bag by injecting caking material of the cement system is expanded a predetermined value A packer characterized in that a check valve mechanism that opens when the cylinder is raised is provided in the cylindrical body . The partitioner is set in a predetermined position in the length direction of the borehole formed in the natural ground, and the packer according to claim 1 is installed in the borehole corresponding to each partitioning site or in the reinforcing pipe inserted and disposed in the borehole. After placing and injecting cement-based caking material into the packer, inflating the bags provided at both ends of the cylindrical body of the packer and closely contacting the inner surface of the borehole or the reinforcing tube, A cement-based caking material is injected into the packer, the pressure in the packer is increased to a predetermined value or more, the check valve mechanism is opened, and the caking material in the packer is placed between the two bag bodies. reinforcing tube or bore hole and is ejected to land Yamauchi between and around the formed partition walls in the partition portion, injecting the consolidating material for each borehole and the natural ground region surrounding partitioned by the partition walls and Natural ground reinforcing construction method, wherein the solidified Te.

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