JP5119132B2 - Insert unit for ground reinforcement and ground reinforcement method using the same - Google Patents

Description

  The present invention is, for example, a natural ground reinforcement method such as a so-called long tip receiving construction or mirror reinforcement construction that reinforces the natural ground in front of the face when excavating a tunnel, in particular, a large number of through-holes on the peripheral surface placed in the natural ground. In a natural ground reinforcement method in which a solidified material is reinforced by injecting a solidified material into a reinforcing pipe having a surrounding area and in the surrounding natural ground, when the solidified material is injected into the reinforcing pipe, it is inserted into the reinforcing pipe and used. The present invention relates to a natural ground reinforcing insert unit and a natural ground reinforcing method using the same.

  Conventionally, for example, when a tunnel is excavated in a weak ground with poor geological conditions, the tunnel is dug while reinforcing the ground in front of the face. In the natural ground reinforcement method that reinforces the ground in front of the face, the arch-shaped reinforcement around the tunnel in front of the face is necessary to prevent peeling near the top of the tunnel prior to tunnel excavation. There are a tip receiving work for providing a body, and a mirror reinforcing work for reinforcing a tunnel excavation region, which is a natural ground ahead of the face mirror part, with a reinforcing material in order to suppress the pushing behavior in front of the face face. In such a ground reinforcement method, there is known a method in which a reinforcing pipe having a large number of through holes (perforated reinforcing pipe) is used as a reinforcing material on a peripheral surface of a steel pipe or the like (for example, Patent Document 1 below). reference).

  FIG. 5 shows an example of a natural ground reinforcement method using a reinforcing pipe as described above, particularly a long tip receiving method using a long reinforcing pipe. A hole h is formed in the mountain 11 by using a drilling machine 12 such as a drill jumbo, and at the same time, a reinforcing pipe 10 having a large number of through holes in the peripheral surface is accommodated in the hole h, The consolidated region G is formed by injecting and solidifying the consolidated material G into the reinforcing tube 10 and the surrounding natural ground 11. In the figure, 13 is a primary sprayed concrete applied to the inner surface of the face mirror part 11a, 14a is a support made of steel or the like, and 14b is a secondary shot concrete applied between adjacent support works 14a and 14a.

  In order to accommodate and arrange the reinforcing tube 10 in the drilling hole h at the same time as the above-described drilling h is performed, conventionally, the reinforcing tube 10 and a tubular drilling rod disposed inside the reinforcing tube 10 are generally used. The so-called double pipe drilling method is used. FIG. 5 shows an example thereof. A tubular drilling rod 15 is inserted into the reinforcing tube 10 and the rear end side of the drilling rod 15 is connected to the guide shell of the drilling machine 12 such as the drill jumbo. It is connected to a rock drill 16 provided on 12a, and a drill bit (not shown) provided at the tip of the drill rod 15 with the rock drill 16 at a predetermined elevation angle in the front ground 11 of the face 11a. Drill holes h. At the same time, as the drilling rod 15 moves forward, the reinforcing tube 10 disposed around the drilling rod 15 is driven so as to be sequentially driven or pulled into the drilling hole h.

  At that time, the reinforcing tube 10 and the drilling rod 15 are each formed in a long length previously formed to a required length, or formed in a necessary length while sequentially adding a short length previously formed. Place in the drilling hole. When the drilling rod 15 is driven to a predetermined depth, a part or all of the drilling rod 15 and a drilling bit (not shown) are withdrawn and collected, and the reinforcing pipe 10 is placed in the drilling h. Next, cement-based or resin-based solidified material G is injected into the reinforcing tube 10, and the reinforcing tube 10 is formed through small through holes (not shown) formed in the reinforcing tube and the peripheral surface of the reinforcing tube 10. The consolidated material G is filled and solidified in the surrounding natural ground 11 to form a consolidated region R, thereby reinforcing the natural ground at the upper front of the face 1a.

  In this case, there are a so-called step injection method and a simultaneous injection method as the injection method of the consolidated material G into the reinforcing pipe 10. In the step injection method, for example, as shown in FIG. 6A, an injection material is injected from the injection pipes 31 and 32 into the partition forming packers 21 and 22 arranged in the reinforcing pipe 10, and the packers 21 and 22 are inserted. The inside of the reinforcing tube 10 is divided into a plurality of regions by inflating, and the consolidated material G is sequentially injected into each of the divided regions from the injection tubes 41 to 43. This injection method has the advantage that effective limited injection is possible because the injection amount and injection pressure of each divided region can be managed accurately. On the other hand, in the simultaneous injection method, for example, as shown in FIG. 6B, a plurality of injection pipes 51 to 53 having different lengths are arranged in the reinforcement pipe 10, and each of the injection pipes 51 to 53 extends into the reinforcement pipe 10. The caking material G is simultaneously injected into the. This injection method has the advantages that the injection can be completed in a short time, a uniform ground improvement effect can be achieved, and the filling amount of the consolidated material G can be reduced.

  However, in any of the above injection methods, the solidified material G is sufficiently filled in the reinforcing tube 10 and then penetrates into the surrounding natural ground. It interferes and the permeability of the consolidated material G to the surrounding ground is deteriorated. Further, even if the injection pressure is increased, the pressure in the reinforcing pipe 10 only rises and does not reach the surrounding natural ground. Therefore, a large amount of the solidified material G is left in the reinforcing tube 10 in a state where it is injected at a high pressure. In particular, in the case of the urethane-based consolidated material G, the urethane in the reinforcing tube 10 foams first and blocks the path of the chemical solution that comes later, so that the permeability to the natural mountain behind the hole is deteriorated. There are problems such as.

  Therefore, in the following Patent Document 2, in order to reduce the cross-sectional area (volume) in the reinforcing pipe as described above and reduce the filling amount of the solidified material in the reinforcing pipe, It has been proposed to insert bar spacers. However, if the volume (volume) of the rod-shaped spacer is small, the effect of reducing the filling amount of the solidified material in the reinforcing tube is small, and if the volume of the rod-shaped spacer is large, insertion into the reinforcing tube may be difficult. There is. In particular, the number of injection pipes is limited because the arrangement space of the injection pipes in the reinforcing pipe is reduced by the amount of the cross-sectional area being reduced by the rod-shaped spacer. In particular, when a packer or the like for forming a partition wall is used, it is necessary to dispose an injection tube therefor, which may make it difficult to dispose the necessary number of injection tubes in the reinforcing tube.

JP-A-8-121073 Japanese Patent Laid-Open No. 7-300850

  The present invention has been proposed in view of the above-described problems. The amount of the consolidated material injected into the reinforcing tube is reduced without reducing the placement space of the injected tube, and the consolidated material is favorably placed in the surrounding natural ground. An object of the present invention is to provide a natural ground reinforcing insert unit that can be infiltrated and a natural ground reinforcing method using the same.

  In order to achieve the above object, a natural ground reinforcing insert unit and a natural ground reinforcing method using the same according to the present invention have the following configurations. That is, the insert unit for reinforcing natural ground according to the present invention reinforces the natural ground by injecting a caking material into the reinforcing pipe having a large number of small through holes on the peripheral surface placed in the natural ground and the surrounding natural ground. In this case, it is an insert unit for reinforcing natural ground that is inserted into the reinforcing pipe and used to expand the diameter of the bag, the water-absorbing polymer accommodated in the bag, and the water supply for supplying water to the bag. The pipe and the injection pipe for injecting the caking material into the reinforcing pipe outside the bag body are integrally assembled so that they can be inserted into the reinforcing pipe in a lump.

  According to another aspect of the present invention, there is provided a natural ground reinforcing method in which a reinforcing pipe having a large number of through-holes on its peripheral surface is placed in the natural ground, and the natural ground reinforcing insert unit according to claim 1 is inserted into the reinforcing pipe. Then, water is supplied into the bag body through the water supply pipe of the insert unit to swell the water-absorbing polymer in the bag body to inflate the bag body, and then the reinforcing member through the injection pipe of the insert unit. By injecting a caking material into the pipe, the caking material is infiltrated and solidified in the reinforcing pipe and in the surrounding ground, thereby forming a reinforcing region.

According to the natural ground reinforcing insert unit configured as described above and the natural ground reinforcing method using the same, the following operational effects can be obtained.
(1) By reducing the amount of consolidated material injected into the reinforcing pipe, it becomes possible to quickly infiltrate the consolidated material into the ground around the reinforcing pipe before it hardens. Can be demonstrated.
(2) Since a bag body capable of expanding the diameter is used, the insertion space for the injection pipe is not reduced, and when inserted into the reinforcing pipe, it can be easily inserted in a reduced diameter state, and when injecting the consolidated material. Prior to that, the volume of the reinforcing pipe is reduced by expanding the diameter of the bag body in the reinforcing pipe, thereby reducing the injection amount of the consolidated material into the reinforcing pipe.
(3) Since the water-absorbing polymer is previously stored in the bag body in order to inflate the bag, the operation is simple because it is only necessary to supply water when the bag is inflated.
(4) If the maximum diameter when the bag body is inflated is smaller than the inner diameter of the reinforcing pipe, even if the inside of the reinforcing pipe is almost completely covered with the bag body, the consolidated material is moved along the inner wall of the reinforcing pipe. The caking material can be circulated substantially over the entire length, and the caking material can be discharged well from the through-hole formed in the peripheral surface of the reinforcing pipe into the ground around the reinforcing pipe.

  Hereinafter, a natural ground reinforcing insert unit according to the present invention and a natural ground reinforcing method using the same will be described in detail with reference to the embodiments shown in the drawings.

  FIG. 1 (a) is a side view showing an embodiment of an insert unit for reinforcing ground according to the present invention, and FIG. 1 (b) is a partially longitudinal side view of the insert unit inserted into a reinforcing pipe. (C) is a partially longitudinal side view of a state in which the bag body in the insert unit is inflated, and FIGS. 2 (a) and 2 (b) are AA and BB enlarged sectional views in FIG.

  The natural ground reinforcing insert unit 1 of the present embodiment includes two bags 2a and 2b that can be expanded in diameter, a water-absorbing polymer P accommodated in the bags 2a and 2b, and water in each bag. Water supply pipes 3a and 3b for supplying water, and three injection pipes 4a to 4c for injecting the consolidated material G into the reinforcement pipe 10 outside the bag bodies 2a and 2b. It is assembled in an integrated manner so that it can be inserted. The number and arrangement positions of the bag bodies 2a and 2b, the water supply pipes 3a and 3b, and the injection pipes 4a to 4c can be changed as appropriate.

  As the water-absorbing polymer P, a 20-fold water-absorbing expansion type highly water-absorbing polymer is used in the present embodiment. In the present embodiment, the bag bodies 2a and 2b that contain the water-absorbing polymer P are water supplied to the water-absorbing polymer P and cloth or the like through which the water-absorbing polymer P before and after absorbing the water does not permeate. As shown in FIGS. 1 (c) and 2, each is formed into an inner and outer double cylindrical shape, and the water-absorbing polymer P is accommodated in a sealed state between the inner and outer cylindrical portions. Each of the bags 2a and 2b can be expanded in diameter, and before the water-absorbing polymer P in each bag absorbs water, it is in a state of being reduced in diameter as shown in FIG. 1 (a). It can be easily inserted into the reinforcing tube 10 as shown in 2 (a). When the water-absorbing polymer P absorbs water and swells, the bags 2a and 2b swell as shown in FIGS. 1 (c) and 2 (b), and the maximum diameter (outside) when the bags swell most. (Diameter) is set to be slightly smaller than the inner diameter of the reinforcing tube 10.

  The bag bodies 2a and 2b formed in the inner and outer double cylindrical shapes are arranged in a substantially straight line, and a core material 5 made of a steel wire material such as a reinforcing bar is inserted into each bag body 2a and 2b. Yes. The core member 5 and each of the bags 2a and 2b are integrally connected and fixed by a connecting tool such as an adhesive tape or string not shown in the drawing. Further, the water supply pipes 3a and 3b and the injection pipes 4a to 4c are arranged along the core material 5, and a static mixer 6 is provided at the tip of each of the injection pipes 4a to 4c. Further, the water supply pipes 3a and 3b, the injection pipes 4a to 4c, and the core member 5 are inserted and fitted at their one ends (ends on the mouth side) into holes of a cap 7 made of rubber or the like that closes the opening end of the reinforcing pipe. They are assembled together by joining. The water supply pipes 3a and 3b, the injection pipes 4a to 4c, and the core material 5 are not only inserted and fitted into the holes of the cap 7, but are also bundled at appropriate locations with a binding tool such as an adhesive tape or a band. Is omitted from the figure.

  In order to construct a ground reinforcement method such as a tip receiving work or a mirror reinforcement work using the insert unit 1 configured as described above, for example, the construction may be performed in the following manner. FIG. 3 shows an example. First, as shown in FIG. 3 (a), a pilot hole h1 is formed in the ground 11 and then a drilling hole h is formed, and a reinforcing tube 10 is inserted into the drilling hole h. . Although the method is appropriate, for example, it can be performed by a double-pipe drilling method as in the conventional example. In this way, the hole h is formed in the ground 11 and when the reinforcing tube 10 is inserted into the hole h, the mouth (opening side end) of the reinforcing tube 10 is formed as shown in FIG. The caulking material 17 is filled between the inner surface of the opening side end portion of the drilling hole h or the inner surface of the lower hole h1, and the opening end of the drilling hole h is closed.

  Next, as shown in FIG. 3 (c) and FIG. 4 (a), the natural ground reinforcing insert unit 1 shown in FIG. 1 (a) is inserted into the reinforcing pipe 10, and then the bag 2a. Since 2b is in a reduced diameter state as described above, it can be easily inserted into the reinforcing tube 10. When the insert unit 1 is inserted into the reinforcing tube 10, the cap 7 is fitted to the open end of the reinforcing tube 10. In the case where the cap 7 is provided integrally with the insert unit 1 as in this embodiment, it is only necessary to fit the cap 7 to the opening end of the reinforcing tube 10, and the cap 7 is provided in the insert unit 1. If not, the cap 7 may be separately fitted into the opening end of the reinforcing tube 10, and the water supply tubes 3 a and 3 b and the injection tubes 4 a to 4 c of the insert unit 1 may be inserted into the holes formed in the cap 7.

  Then, as shown in FIG. 3 (d), water is supplied from the water supply pipes 3a and 3b to the bags 2a and 2b of the insert unit 1 to swell the water-absorbing polymer P in the bags 2a and 2b, thereby The bag bodies 2a and 2b are inflated to expand the diameter. At that time, the bag bodies 2a and 2b are set so that the maximum diameter when the bag bodies 2b are expanded most is slightly smaller than the inner diameter of the reinforcing tube 10 in the present embodiment. There is a slight gap S between 2b and the inner peripheral surface of the reinforcing tube 10.

  In this state, as shown in FIG. 3E, the consolidated material G is injected from the injection pipes 4a to 4c of the insert unit 1. The material of the consolidated material G is appropriate, but in this embodiment, A type of urethane-based consolidated material that mixes two liquids of liquid A and liquid B is used. Specifically, polyether polyol is used as the liquid A and polymeric MDI is used as the liquid B, respectively, and these are mixed and injected simultaneously from the injection ports 4a to 4c provided near the mouth of the reinforcing tube 10, and each of the injection tubes The urethane-based solidified material G is discharged while stirring with a static mixer 6 provided in the vicinity of the tips of 4a to 4c.

  The consolidated material G injected into the reinforcing pipe 10 from the injection pipes 4a to 4c as described above is simultaneously discharged from three different locations in the reinforcing pipe 10 and permeates and foams in the reinforcing pipe 10. At this time, the bag bodies 2a and 2b in the reinforcing pipe 10 do not partition the inside of the reinforcing pipe 10, but form an appropriate flow path for the consolidated material G in the reinforcing pipe 10, and thus the bag body 2a. -The consolidated material G can be distribute | circulated between 2b and the inner surface of the reinforcement pipe | tube 10. FIG. In particular, when the gap S as described above is formed between the bag bodies 2 a and 2 b and the inner surface of the reinforcing tube 10, it becomes a flow path along the inner surface of the reinforcing tube 10 and the consolidated material G is connected to the reinforcing tube 10. It can be distributed uniformly and quickly over almost the entire length of the inner surface. At the same time, the solidified material G is satisfactorily placed in the surrounding natural ground 11 as shown in FIGS. 3 (f) and 4 (b) from the small through hole 10a provided over almost the entire length of the peripheral surface of the reinforcing pipe 10. The consolidated region R can be uniformly formed around the reinforcing pipe 10 by flowing out evenly. Further, it is possible to reduce the amount of the consolidating material G injected into the reinforcing tube 10 by an amount substantially corresponding to the volume of the inflated bag bodies 2a and 2b, thereby reducing the cost.

  As described above, the present invention includes the bag bodies 2a and 2b capable of expanding the diameter, the water-absorbing polymer P accommodated in the bag body, the water supply pipes 3a and 3b for supplying water into the bag body, and the bag body. The injection pipes 4a to 4c for injecting the caking material into the outer reinforcement pipe are integrally assembled so as to be insertable into the reinforcement pipe in a lump so as to constitute a natural ground reinforcement insert unit 1, and the natural ground Since the reinforcing insert unit 1 is inserted into the reinforcing pipe 10 placed in the natural ground 11 to reinforce the natural ground, the amount of the consolidated material G filled in the reinforcing pipe 10 is determined by the bag body. 2a and 2b can be reduced by an amount substantially corresponding to the swelled volume, and the consolidated material G can quickly flow out into the ground around the reinforcing tube 10 before the consolidated material is solidified. The consolidated region R can be formed. As a result, the conventional problems can be solved and the natural ground reinforcement can be performed satisfactorily, and not only the tunnel tip construction as in the above embodiment, but also the mirror reinforcement work and other various natural ground reinforcements. It can also be applied well to construction methods (including ground reinforcement construction methods).

(A) is a side view showing an embodiment of an insert unit for reinforcing ground according to the present invention, (b) is a partially longitudinal side view of the insert unit inserted into a reinforcing tube, and (c) is the insert. The partially vertical side view of the state which inflated the bag body in a unit. (A) And (b) is an AA and BB expanded sectional view in FIG. (A)-(f) is a longitudinal cross-sectional view which shows the construction example of the natural ground reinforcement construction method by this invention. (A) and (b) are CC and DD expanded sectional views in FIG. (A) is a longitudinal side view showing an example of a front receiving construction as a natural ground reinforcement construction method, and (b) is a cross-sectional front view thereof. (A) And (b) is explanatory drawing of a binder injection | pouring method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insert unit 2a, 2b Bag 3a, 3b Water supply pipe 4a-4c Injection pipe 5 Core material 6 Static mixer 7 Cap 10 Reinforcement pipe 11 Ground mountain 17 Caulking material P Water-absorbing polymer G Consolidation material R Consolidation area S Gap h Borehole

Claims (3)

A natural ground which is inserted into the reinforcing pipe and used to reinforce the natural ground in the reinforcing pipe having a large number of through-holes on the peripheral surface placed in the natural ground and the surrounding natural ground. A reinforcing insert unit,
A bag body capable of expanding diameter, a water-absorbing polymer accommodated in the bag body, a water supply pipe for supplying water into the bag body, and an injection pipe for injecting a caking material into a reinforcing pipe outside the bag body, Are assembled together so that they can be inserted into the reinforcing pipe in a batch .
An insert unit for reinforcing natural ground , wherein the maximum diameter when the bag body is most inflated is set to be smaller than the inner diameter of the reinforcing pipe . A reinforcing pipe having a large number of through-holes on the peripheral surface is placed in the natural ground, and the insert unit for reinforcing natural ground according to claim 1 is inserted into the reinforcing pipe, through the water supply pipe of the insert unit. The water is then supplied into the bag body to swell the water-absorbing polymer of the bag body to inflate the bag body,
The reinforcing material is injected into the reinforcing tube through the injection tube of the insert unit, and the reinforcing material is infiltrated and solidified in the reinforcing tube and the surrounding ground, thereby forming a reinforcing region. Natural mountain reinforcement method. The ground reinforcement method according to claim 2 , wherein a urethane foam chemical is injected into the reinforcing pipe as the consolidated material.

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