JP3615511B2 - Ground reinforcement method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a natural ground reinforcement method such as a tunnel tip receiving method or a mirror part reinforcing method as a natural ground advance reinforcement method applied when excavating a tunnel or an underground cavity, for example.
[0002]
[Prior art]
Conventionally, for example, a so-called injection-type long tip receiving method is known as a method for pre-reinforcing a ground in front of a tunnel face. The feature of this method is that it uses a drill jumbo that is used for tunnel excavation without the need for a dedicated machine, and it uses a diameter expansion bit attached to the tip of a drilling rod inserted into a reinforcing pipe such as a steel pipe to be cast. Drilling holes with flushing water from a rock machine, adding about 3m of reinforcing pipes along with the drilling holes using a double pipe drilling system, and placing long reinforcing pipes. It is characterized by a long receiving length compared to the reinforcement work.
[0003]
In order to properly inject a solidified material (injection material) such as a chemical solution into such a long region, the inside of the reinforcing pipe 1 placed in the natural ground R as shown in FIG. It is desirable to divide into several sections S1 to S4 and inject the consolidated material into each section.
[0004]
However, such a receiving method is predicated on drilling with a drill jumbo, and a relatively small diameter reinforcing pipe (generally with an inner diameter of about 100 mm) is placed in comparison with other methods using a dedicated machine (pipe roof, etc.). Therefore, the number of injection tubes that can be set in the reinforcing tube is limited.
[0005]
For example, as shown in FIG. 12, when four sections (rooms) S1 to S4 are formed by four packers 2 and the consolidated material is injected into each packer 2 and each section S1 to S4, the above 4 Four infusion pipes 31 to 34 for inflating each packer, and four infusion pipes 41 to 44 for injecting the consolidated material into each of the sections S1 to S4, a total of eight infusion pipes Must be set in the reinforcing tube 1.
[0006]
In addition, if the length of the prior construction as described above becomes longer, better injection can be obtained by dividing the entire length into more sections, but the number of necessary injection tubes increases accordingly. However, there are many cases where it cannot be accommodated in a reinforcing pipe having a limited diameter. Therefore, the number of injection pipes accommodated in the reinforcing pipe is substantially limited, thereby limiting the number of compartments. Moreover, since the length per section will become long if the number of divisions is restricted, there is a concern about uneven injection of the consolidated material into the ground.
[0007]
In addition, the longer the first construction, the more the geological conditions will be injected, and the required injection conditions such as the type of consolidated material, the type of injection, on the near side and the back side, or depending on the section. Although the timing, packing method, and the like are different, there is a problem that if the number of sections is limited, such a request cannot be met and a sufficient and good reinforcing effect cannot be obtained.
[0008]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above-mentioned problems, and even when the casting length becomes long, the injection section is appropriately partitioned so that the most effective injection can be performed in each section. An object of the present invention is to provide a natural ground reinforcement method capable of obtaining a sufficient and good ground reinforcement effect.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the ground reinforcement method according to the present invention has the following configuration. That is, a packer injection tube for accommodating and arranging a plurality of inflatable packers having a liquid passing portion at predetermined intervals in a drilling hole formed in a natural ground and injecting a consolidated material into each packer. Is formed by a single common tube body, and a section injection pipe for injecting a consolidated material into a plurality of sections partitioned by the packer is provided separately for each of the plurality of sections, and the packer injection pipe is provided. The filler is simultaneously injected into each of the packers via the swell to expand each packer, and the filler is injected and cured from the liquid passing portion into the borehole and the surrounding ground. After the region is formed, the ground is reinforced by injecting and solidifying the solidified material in the drilling holes in each of the sections and in the surrounding ground through the section injection pipe .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the ground reinforcement method according to the present invention will be described in detail based on the embodiment shown in the drawings.
[0011]
FIG. 1 is a longitudinal sectional view of an example in which the ground reinforcement method according to the present invention is applied to a tunnel tip receiving, particularly an injection-type long tip receiving by a double pipe drilling method, and FIG. 2 is a transverse sectional view of FIG. 1 is a partially enlarged view of FIG. 1, FIG. 4 (a) is an enlarged sectional view in which the length direction is reduced, and FIG. 4 (b) is a partially enlarged view thereof.
[0012]
In the figure, reference numeral 1 denotes a reinforcing pipe made of a steel pipe or the like accommodated in a drilling hole H formed in a natural ground R. The total length of the reinforcing pipe 1 is assumed to be about 12.5 to 20 m in this embodiment. As shown in FIG. 1, it is provided so as to be inclined at a predetermined angle from the lower end of the support work P closest to the face W toward the front ground. Further, as shown in FIG. 5, a large number of through holes 1a are formed on the peripheral wall surface of the reinforcing pipe 1 at a predetermined pitch over the entire length, and the predetermined length is determined according to the required driving length. A reinforcing pipe is used by being connected by a coupler 10.
[0013]
A plurality of inflatable packers 2 are arranged in the reinforcing tube 1 at a predetermined interval. In this embodiment, four packers 2 are accommodated and arranged as shown in FIG. The natural ground in and around the pipe 1 is divided into four sections S1 to S4. In addition, the arrangement position and the number of the packers 2 are appropriate, and may be set as appropriate according to the ground condition to be reinforced.
[0014]
The structure of the packer 2 is appropriate. For example, as shown in FIG. 6, the packer 2 has a liquid passing part 2 a made of a liquid permeable material such as a cloth at the center, and is continuously made of rubber or the like at both ends. It is more preferable to use a dumbbell-shaped bag having a bulging portion 2b made of a non-liquid-permeable material.
[0015]
In the present invention, the packer injection tube 3 for injecting the caking material into each packer 2 is composed of a single tube as shown in FIGS. 4 and 7. The discharge hole 3c for discharging the binder is formed in accordance with the position where the packer 2 is set, and the distal end portion 3a of the injection tube 3 is configured to open into the packer disposed on the deepest side of the hole. Yes.
[0016]
In this embodiment, as shown in FIGS. 4 and 7, four injection pipes for sections 41 to 44 for injecting the consolidated material into the sections S1 to S4 partitioned by the packer 2 are provided. In a state where the tubes 41 to 44 and the packer injection tube 3 are bundled together, the packers 2 are covered so as to cover the discharge holes 3c of the injection tube 3, and the end portions of the packers are covered. Tighten and fix with a band or string not shown in the figure. As a result, the injection pipes 3 and 41 to 44 and the packers 2 are integrated as one unit as shown in FIG. 7B, and inserted into the reinforcing pipe 1 as shown in FIG. 7C. It is the structure to do.
[0017]
In constructing the natural ground reinforcement method constructed as described above, for example, construction may be performed in the following manner. First, using a drill jumbo J or the like shown in FIG. 1 as a hole drilling machine, a pilot hole with a predetermined depth as shown in FIG. H1 is formed. In the figure, C is concrete provided on the surface of the face mirror part W.
[0018]
Next, a hole H having a predetermined depth is provided, and the reinforcing pipe 1 is loaded into the hole H. The hole drilling method and the shape of the hole bit are arbitrary, but in this embodiment, A drill bit H is simultaneously formed by a ring bit 11 attached to the tip of the reinforcing pipe 1 and a drill rod 13 having a center bit 12 engaged with the inner hole of the ring bit 11 attached to the tip. The reinforcing tube 1 is loaded in the hole H.
[0019]
That is, as shown in FIG. 8B, the drill jumbo J is rotated while rotating the drilling rod 13 with the center bit 12 attached to the tip of the drilling rod 13 engaged with the inner hole of the ring bit 11. As the ring bit 11 is advanced, the reinforcing pipe 1 provided integrally with the center bit 12 and the ring bit 11 is drilled into the drill hole H. It is configured to be pulled in sequentially. At that time, the reinforcing pipe 1 is sequentially connected and inserted by the coupler 10 or the like as necessary. The same applies to the drilling rod 13.
[0020]
As described above, the hole H having a predetermined depth is formed, and at the same time the reinforcing tube 1 is loaded in the hole H, the hole 13 is reversed and the center bit 12 and the ring bit 11 are reversed. When the engagement is released and the drilling rod 13 is pulled out as shown in FIG. 8C, the center bit 12 is recovered integrally therewith, and the ring bit 11 remains in the drilling hole H together with the reinforcing tube 1.
[0021]
Instead of using the ring bit 11 or the center bit 12 as described above, it can be inserted into the reinforcing tube 1 and when drilling, the tip of the reinforcing tube 1 is expanded to the same extent as or larger than the outer shape of the reinforcing tube 1. Drilling may be performed using an openable bit that can be opened.
[0022]
When the drilling operation and the loading operation of the reinforcing tube 1 are completed as described above, the packer 2, the packer injection tube 3, and the section injection tubes 41-1 in the reinforcement tube 1 as shown in FIG. 9A. 44 is inserted, and if they are assembled as one unit as described above, they can be easily loaded. Further, in the present invention, only one packer injection tube 3 may be used regardless of the number of packers 2, so that the number of packer injection tubes 3 inserted into the reinforcing tube 1 and the arrangement space thereof can be reduced. Even a reinforcing pipe having a small diameter can be easily loaded.
[0023]
Next, the consolidation material G is injected into each packer 2 through the above-described packer injection tube 3, and as the consolidation material, for example, an immediate-hardening material such as a urethane resin having a gel time of 30 seconds to several minutes is used. The gel time may be appropriately adjusted according to the casting length or the like. In this way, by injecting the caking material into each packer 2 through one common packer injection tube 3, the caking material is injected into each packer almost simultaneously and at the same pressure without any deviation. can do.
[0024]
By injecting the caking material into each packer 2 as described above, first, the bulging portions 2b at both ends of each packer swell, and the outer peripheral surface of the bulging portion 2b presses against the inner surface of the reinforcing tube 1 for reinforcement. The inside of the pipe 1 is partitioned into a plurality of sections S1 to S4. Further, when the binder is injected into each packer 2, the binder flows out from the liquid passing portion 2a at the center of each packer into the reinforcing tube 1, and the binder G that has flowed into the reinforcing tube 1 is attached to both ends of the packer. Without flowing out into the sections S1 to S4 by the bulging portions 2b and 2b, the bulging portion 2b flows out into the drilling hole from the through hole 1a formed in the peripheral wall surface of the reinforcing tube 1, and further into the surrounding natural ground R The partition wall-like consolidated region G1 is formed so as to divide the natural ground around each of the packers 2 into a plurality of pieces in the longitudinal direction of the reinforcing tube 1.
[0025]
The consolidated region G1 formed as described above is provided corresponding to each of the packers 2 so that the inside of the reinforcing tube 1 and the surrounding natural ground R can be divided into a plurality of packers 2 and the ground. The intermediate partition wall is partitioned into a plurality of sections (four in the figure) S1 to S4. In addition, thereby, one end of the plurality of section injection pipes 41 to 44 is in a state of communicating and opening in the reinforcing pipe 1 in each section.
[0026]
In that state, it is only necessary to inject the consolidation material into the reinforcement pipes 1 in the sections S1 to S4 through the section injection pipes 41 to 44 at the same time or in any order. For example, a urethane resin equivalent to that injected into the packer is used.
[0027]
The solidified material injected into the reinforcing pipe 1 in each of the sections S1 to S4 is filled in the reinforcing pipe 1 and then passes through the small holes 1a around the reinforcing pipe 1 to the surrounding natural ground R. The solid region is reinforced by forming a consolidated region G2 by the consolidated material G as shown in FIG.
[0028]
As described above, after placing the reinforcing pipe 1, the plurality of packers 2 are first inflated at the same time, and further, the binder is infiltrated and hardened from each packer 2 into the surrounding natural ground R. A partition-shaped consolidated region G1 is formed on the inner surface, and the solid material G is injected through the section injection tubes 41 to 44 in any order of the sections S1 to S4 partitioned by the consolidated region G1. By performing this, it is possible to completely inject an arbitrary solidified material (chemical solution) at an arbitrary timing into a desired section without any trouble. Therefore, it is possible to perform a desired injection in each space that is surely partitioned even under different ground conditions by improving the ground over a long length.
[0029]
In addition, although the said embodiment was applied to the injection-type long tip receiving method by what is called a double pipe drilling system which inserts the reinforcement pipe | tube 1 in this drilling hole simultaneously with drilling by the rod 13 for drilling holes, The reinforcing pipe 1 may be inserted into the hole after all the hole drilling operations by the hole drilling rod 13 or the like are completed.
[0030]
Moreover, although the said embodiment used the steel pipe as the reinforcement pipe | tube 1, you may use synthetic resin pipes, such as another material, for example, FRP. In particular, when part or all of the reinforcing pipe 1 is crushed and removed during tunnel excavation, it is desirable to use the synthetic resin pipe as described above. For example, the present invention can be applied to a method of widening the tunnel cross section as shown in FIG.
[0031]
Furthermore, the present invention is not limited to tunnel tip construction, but can be applied to other construction methods as long as it is an injection-type ground reinforcement method. For example, the invention is applied to an injection-type long mirror part reinforcement method as shown in FIG. You can also. Also in this case, it is desirable to use a synthetic resin tube as described above.
[0032]
In addition, the reinforcing pipe 1 is not necessarily a reinforcing pipe, for example, when the self-supporting property of the drilled hole is good and sufficient strength can be obtained without the reinforcing pipe 1 (for example, placing a pile). It may not be used. Further, it is possible to inject the consolidated material while pulling out the reinforcing tube inserted into the drilling hole by the double pipe drilling method as described above or after pulling it out.
[0033]
【The invention's effect】
As described above, the ground reinforcement method according to the present invention comprises a packer injection pipe for injecting a consolidated material into a plurality of packers as a single common pipe, and the above-mentioned via the injection pipe. Since the consolidation material is injected into each packer at the same time, the number of injection tubes can be reduced as compared with the conventional case where an injection tube is provided for each packer. In addition, for example, when a packer is inserted into the reinforcing pipe, for example, it is possible to easily load even a small diameter reinforcing pipe. In addition, since the consolidated material is injected into a plurality of packers via a common injection tube, there is an effect that the packers can be easily injected simultaneously without shifting to each packer.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an example in which the ground reinforcement method according to the present invention is applied to a tunnel tip receiving work.
FIG. 2 is a transverse cross-sectional view in FIG.
3 is an enlarged view of a part of FIG.
4A is an enlarged cross-sectional view in which the length in the longitudinal direction of the leading work in FIG. 3 is slightly reduced.
(B) is an enlarged view of a part thereof.
FIG. 5A is a partially longitudinal side view of a reinforcing pipe.
(B) is a side view showing a connection example of a reinforcing pipe.
FIG. 6 is a partially longitudinal side view of the packer.
FIG. 7A is a longitudinal side view of an injection tube for a packer.
(B) is a side view of an assembly unit of a packer and an injection tube.
(C) is a longitudinal side view of the unit loaded in the reinforcing pipe.
FIGS. 8A to 8C are explanatory views showing a construction example of a natural ground reinforcement method according to the present invention.
FIGS. 9A to 9C are explanatory views showing a construction example of a natural ground reinforcement method according to the present invention.
FIG. 10 is an explanatory view showing another construction example of the natural ground reinforcing method according to the present invention.
FIG. 11 is an explanatory view showing still another construction example of the natural ground reinforcing method according to the present invention.
FIG. 12 is an explanatory view showing a construction example of a conventional ground reinforcement method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Reinforcement pipe 2 Packer 3 Packer injection pipe 41 to 44 Section injection pipe G Ground mountain H

Claims (2)

A plurality of inflatable packers having a liquid passing part are accommodated and arranged at predetermined intervals in a drill hole formed in a natural ground, and a common packer injection pipe is used to inject a consolidated material into each packer. In addition to being configured by one tube body, a section injection pipe for injecting the consolidated material into the plurality of sections partitioned by the packer is provided separately for each of the plurality of sections, and the packer injection pipe is interposed therebetween. Simultaneously injecting a caking material into each packer to expand each packer and injecting and hardening the caking material into the drilling hole and surrounding ground from the liquid passing portion to form a partition-like consolidated area. After the formation , a natural ground reinforcement method for reinforcing a natural ground by injecting and solidifying a solidified material into the borehole of each of the above sections and the surrounding natural ground through the above-mentioned section injection pipe . The packer is formed substantially entirely bag shape, characterized by having a liquid passage portion which center portion than both end portions exhibit a diameter of approximately dumbbell shape and formed with liquid permeability material to the central portion at the time of inflation The ground reinforcement method according to claim 1.

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