JP2011074738A - Anchor and construction method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anchor and a construction method thereof capable of increasing a resistance force to a floating force of a wing part, improving the rigidity of the wing part, achieving a lightweight wing part, preventing the excess hammering of the wing part, hammering the wing part in such a way that the surface of natural ground may match with the upper end of wings, and preventing the coming-off of the anchor due to the bending of the upper section of an anchor body part. <P>SOLUTION: The anchor includes the anchor body part 1 and the wing part 2 in a form different from the anchor body part 1. The wing part 2 includes a hollow shaft 3 in which the anchor body part 1 is fitted and a plurality of wings 4 radially fixed to the hollow shaft 3. The hollow shaft 3 comprise a plurality of split hollow shafts 3a provided at intervals in the axial direction of the hollow shaft 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention can increase the resistance of the anchor and its construction method, in particular, the resistance against the lifting force of the blade, can improve the rigidity and weight of the blade, and can prevent the blade from being driven excessively. In addition, it relates to an anchor that can drive the blade part so that the surface of the natural ground and the upper end of the blade coincide with each other, and can prevent the anchor from coming off due to the bending of the upper part of the anchor main body part, and its construction method. is there.

  Conventionally, for example, as shown in FIG. 6, in order to stretch the rock fall protection net 6 on the inclined ground mountain 5 where there is a risk of rock fall, the rock fall protection net 6 is attached to the wire rope 7 and the anchor constructed on the ground mountain 5. A wire rope 7 was fixed to A. The natural ground 5 includes a bedrock 12 and a topsoil layer 13 on the bedrock 12.

  Patent Document 1 (Japanese Patent No. 38137781) discloses an anchor having the following structure as an example of the anchor A. Hereinafter, this anchor A is referred to as a conventional anchor and will be described with reference to the drawings.

  7 is a plan view showing a blade portion of a conventional anchor, FIG. 8 is a partially broken front view showing the blade portion of the conventional anchor, FIG. 9 is a front view showing an anchor main body portion of the conventional anchor, and FIG. The front view which shows the state which fixed the anchor main-body part of the anchor to the rock mass, FIG. 11 is sectional drawing which shows the state which fixed the wire rope to the conventional anchor constructed in the natural ground.

  As shown in FIGS. 7 to 11, the conventional anchor includes an anchor main body portion 8 made of a bar or a pipe fixed to the rock 12 of the natural ground 5, and an anchor main body portion 8 fitted into the upper portion of the anchor main body portion 8. Consists of a separate blade 9. The anchor main body 8 is fixed at a substantially right angle to the rock 12 (the ground surface), and the upper end of the anchor main body 8 protrudes slightly from the topsoil layer 13. After the construction, the wire rope 7 is fixed (see FIG. 11).

  The blade portion 9 includes a hollow shaft 10 into which the anchor main body portion 8 is fitted, and a plurality of (four in this example) blades 11 fixed radially around the hollow shaft 10, and is driven into the topsoil layer 13. . The reason why the blades 11 are fixed in a radial manner is to eliminate the direction of improving the lateral strength of the anchor main body 8. The hollow shaft 10 has an inner diameter into which the anchor main body 8 can be inserted. The lower end of the blade 11 is inclined upward from the inside toward the outside so that the blade 11 is easily driven into the ground. The blade portion 9 has a function of improving the lateral strength. Below, the function of the blade | wing part 9 is demonstrated.

  As described above, the wire rope 7 is fixed to the upper end of the anchor main body 8. Since the wire rope 7 is normally stretched along the inclined ground 5, a load is applied to the anchor main body portion 8 in a direction substantially orthogonal to the axis of the anchor main body portion 8. The load component is slight. As described above, the lower part of the anchor main body 8 is fixed to the bedrock 12, but the upper part is inserted into the soft topsoil layer 13 as compared with the bedrock 12, so the fixing force is weak. As a result, the upper part of the anchor main body 8 is easily bent due to a tensile load generated in the wire rope 7 when a falling rock is generated. When the upper part of the anchor main body 8 is bent, the load component in the extraction direction of the anchor main body 8 increases, and the anchor may possibly come out of the rock mass 12 in some cases. However, if the blade portion 9 is fitted into the upper portion of the anchor body portion 8 and the blade portion 9 is driven into the topsoil layer 13, the upper portion of the anchor body portion 8 is difficult to bend due to the reaction force from the topsoil layer 13, and as a result, the anchor Can be prevented from coming out.

  In order to put a rockfall protection net on a natural ground inclined by the conventional anchor constructed in this way, the following is performed.

  First, as shown in FIG. 10, an anchor insertion hole 14 is drilled by a rock drill through a topsoil layer 13 in a rock 12 at a predetermined position. Next, a coagulant such as cement is injected into the anchor insertion hole 14, and the anchor body 8 is inserted into the anchor insertion hole 14 before the coagulant is cured. Depending on the bedrock 12, the anchor main body 8 may be directly driven into the bedrock 12 without opening the anchor insertion hole 14. Next, after curing of the coagulant, the blade portion 9 is fitted into the upper portion of the anchor body portion 8 protruding from the topsoil layer 13, and the blade portion 9 is placed in the topsoil layer 13 using the anchor body portion 8 as a guide as shown in FIG. Type in.

  Thus, if a conventional anchor is constructed in the natural ground 5, the wire rope 7 will be fixed to the upper end of the anchor main-body part 8 which protruded from the topsoil layer 13 (refer FIG. 11). As a result, as shown in FIG. 6, the rockfall protection net 6 can be stretched on the inclined ground mountain 5 where there is a risk of rockfall.

Japanese Patent No. 38137781

  According to the above-described conventional anchor, since the lateral strength of the upper portion of the anchor body portion 8 is improved by fitting the blade portion 9 into the anchor body portion 8, the anchor is prevented from being pulled out due to the bending of the anchor body portion 8. be able to. In addition, the anchor body 8 and the blade 9 are separated from each other, and after fixing the anchor body 8 to the bedrock 12, the blade 9 is driven into the topsoil layer 13. It has the effect that it can be driven into the topsoil layer 13 without being displaced as a guide.

  However, the conventional anchor has the following problems.

  (A) Since the blade portion 9 is only fitted into the anchor main body portion 8, resistance to the lifting force of the blade portion 9 is small.

  (B) Since the blade 11 is formed of a flat plate, the rigidity of the blade 11 is small. As a result, the blade 11 may be deformed when the blade portion 9 is driven.

  (C) Since the blade | wing 11 is formed with the flat plate, there exists a possibility that the blade | wing part 9 may be driven too much. The reason for this is that when the blade 11 is viewed from above, the thin plate thickness portion of the blade 11 can only be seen, and its position is difficult to check. Because it is difficult.

  (D) Since the blade | wing 11 is formed with the flat plate, it is difficult to drive in the blade | wing part 9 so that the natural ground surface and the upper end of the blade | wing 11 may correspond. The reason for this is that when the blade 11 is viewed from above, the thin plate thickness portion of the blade 11 can only be seen, and its position is difficult to confirm. Because it is difficult. When the blade part 9 is driven so that the surface of the natural ground and the upper end of the blade 11 coincide with each other, that is, when the blade part 9 is driven into the anchor body part 8 without bending, the lateral direction of the upper part of the anchor body part 8 The original function of the blade portion 9 for improving the proof stress is exhibited. However, since there is a gap (S) (see FIG. 3 described later) between the anchor main body 8 and the hollow shaft 10 of the blade part 9, the blade part 9 is inclined by the amount of the gap (S). Easy to be driven into. When the blade portion 9 is driven obliquely, the original function of the blade portion for improving the lateral strength of the upper portion of the anchor main body portion 8 is impaired.

  (E) Since the gap (S) is open, the upper portion of the anchor body 8 may be bent by the gap (S) due to the load. When the upper part of the anchor main body 8 is bent, the load component in the extraction direction of the anchor main body 8 increases, and the anchor may possibly come out of the rock mass 12 in some cases.

  (F) Since the blade portion 9 includes the hollow shaft 10 and the plurality of blades 11, the weight increases.

  Therefore, the object of the present invention is to increase the resistance to the lifting force of the blade portion, to improve the rigidity and weight of the blade portion, and to prevent the blade portion from being driven excessively. The blade part can be driven easily so that the surface and the upper end of the blade coincide with each other, and the anchor body part is bent by the load by the gap (S) between the anchor body part and the hollow shaft of the blade part. An object of the present invention is to provide an anchor and a method for constructing the anchor, which have the advantage of preventing the anchor from being pulled out due to the failure.

  The present invention has been made to achieve the above object, and is characterized by the following.

  The invention according to claim 1 includes an anchor main body portion and a separate wing portion from the anchor main body portion, and the wing portion is radially fixed to the hollow shaft into which the anchor main body portion is fitted and the hollow shaft. The hollow shaft is composed of a plurality of divided hollow shafts provided at intervals in the axial direction of the hollow shaft.

  The invention according to claim 2 is characterized in that, in the anchor according to claim 1, the upper end of the blade is bent.

  The invention according to claim 3 is characterized in that, in the anchor according to claim 2, the bending angle of the upper end of the blade is a right angle.

  The invention according to claim 4 is characterized in that, in the anchor according to any one of claims 1 to 3, a protrusion is formed on the outer peripheral surface of the divided hollow shaft.

  The invention described in claim 5 is characterized in that in the anchor according to any one of claims 1 to 4, the lower end of the blade is inclined upward from the inside toward the outside. is there.

  According to the sixth aspect of the present invention, the anchor main body is fixed to the natural ground, and then a blade part separate from the anchor main body is fitted into the anchor main body, and the upper end of the blade part is the natural ground. The blade portion is driven until it coincides with the surface, and the blade portion includes a hollow shaft into which the anchor main body portion is fitted, and a plurality of blades radially fixed to the hollow shaft. It is characterized by comprising a plurality of divided hollow shafts provided at intervals in the axial direction of the shaft.

  According to the seventh aspect of the present invention, a blade portion is driven into a natural ground until the upper end of the blade portion coincides with the surface of the natural ground, and then an anchor main body portion separate from the blade portion is used as a guide. The blade portion is composed of a hollow shaft into which the anchor main body portion is fitted and a plurality of blades fixed radially to the hollow shaft, and the hollow shaft is an axial direction of the hollow shaft. It is characterized by comprising a plurality of divided hollow shafts provided at intervals.

  According to the present invention, the following effects are brought about.

  (1) By forming the hollow shaft of the blade portion into which the anchor main body portion is fitted with a plurality of divided hollow shafts, when a lifting force is applied to the blade portion, the blade portion is formed by the thick portion of each divided hollow shaft. Resistance to the lifting force is generated. As a result, the lifting of the blade portion can be suppressed.

  (2) Since the hollow shaft is composed of a plurality of divided hollow shafts, a part of the anchor body part fitted into the hollow shaft and the ground are in direct contact with each other, so that a lateral load is applied to the anchor body part. In this case, the resistance force against the load for bending the anchor main body is increased. As a result, sagging or the like hardly occurs on the wire rope. In the conventional anchor in which earth and sand do not enter the gap (S) between the anchor main body and the hollow shaft, the anchor main body has nothing to resist, so the load bends by the gap (S) due to the load. Is likely to occur.

  (3) The rigidity of the blade can be increased by bending the upper end of the blade of the blade portion into a right angle, an acute angle, or an arc shape.

  (4) By bending the upper end of the blade of the blade portion at a right angle, when the blade portion is driven, it is easy to visually confirm the upper end of the blade, so that the blade portion can be prevented from being driven excessively.

  (5) At the time of driving the blade portion, the upper end of the blade can be easily confirmed by visual observation, so that the blade portion can be driven so that the ground surface and the upper end of the blade coincide with each other.

  (6) By comprising the hollow shaft of a blade | wing part by a some division | segmentation hollow shaft, the weight reduction of a blade | wing part can be achieved compared with the case where a hollow shaft is not divided | segmented.

It is a perspective view which shows the blade | wing part of the anchor of this invention. It is a fragmentary sectional view which shows the blade | wing part of the anchor of this invention, (a) shows the blade | wing bent at acute angle, (b) shows the blade | wing bent in circular arc shape. It is the sectional view on the AA line of FIG. 1 which omitted the blade | wing. It is sectional drawing which shows the blade | wing part of this invention driven into the topsoil layer. It is sectional drawing which shows the anchor of this invention fixed to the natural ground. It is a schematic perspective view which shows the falling rock protection net stretched on the inclined natural ground. It is a top view which shows the blade | wing part of the conventional anchor. It is a partially broken front view which shows the blade | wing part of the conventional anchor. It is a front view which shows the anchor main-body part of the conventional anchor. It is a front view which shows the state which fixed the anchor main-body part of the conventional anchor to the rock mass. It is sectional drawing which shows the state which fixed the wire rope to the conventional anchor constructed in the natural ground.

  One embodiment of the anchor of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a blade portion of an anchor according to the present invention.

  As shown in FIG. 1, the anchor of the present invention includes an anchor main body 1 made of a bar or a pipe fixed to a rock 12 (see FIG. 6) of a natural ground 5, and an anchor fitted into the upper portion of the anchor main body 1. The main body part 1 is composed of a blade part 2 which is a separate body. The anchor main body 1 has a length that slightly protrudes from the topsoil layer 13 on the rock 12, and after the anchor is constructed on the ground 5, the wire rope 7 is fixed to the upper end of the anchor main body 1. (See FIG. 5).

  The blade portion 2 includes a hollow shaft 3 into which the anchor main body portion 1 is fitted, and a plurality of (four in this example) blades 4 fixed radially around the hollow shaft 3, and is driven into the topsoil layer 13. . The reason why the blades 4 are fixed in a radial manner is to eliminate the direction of improving the lateral strength of the anchor main body 1. The hollow shaft 3 has an inner diameter into which the anchor main body 1 can be inserted. As shown in FIG. 3, a gap (S) is formed between the anchor main body 1 and the hollow shaft 3.

  As shown in FIG. 3, the hollow shaft 3 of the blade portion 2 is composed of a plurality (three in this example) of divided hollow shafts 3a. In this way, by forming the hollow shaft 3 by the plurality of divided hollow shafts 3a, when a lifting force is applied to the blade portion 2 driven into the natural ground 5, a thick portion (T ) Has a surface perpendicular to the direction of the lifting force, so that the internal frictional resistance of the natural ground starts from the outer end of the upper surface of the thick portion (T) of the hollow shaft 3a embedded in the natural ground. The weight of the soil within a range that spreads outward by an angle (generally about 30 ° with earth and sand) acts as a resistance against the lifting force of the hollow shaft 3. As a result, the floating of the blade part 2 can be suppressed. In addition, if the protrusion part 3b (refer FIG. 3) is formed in the outer surface of each division | segmentation hollow shaft 3a, the resistance force with respect to the lifting force of the blade | wing part 2 can further be increased.

  Moreover, weight reduction of the blade | wing part 2 can be achieved by comprising the hollow shaft 3 by the some division | segmentation hollow shaft 3a. Moreover, as shown in FIG. 3, since a part of the anchor main body 1 fitted in the hollow shaft 3 and the ground 5 are in direct contact with each other, when a lateral load is applied to the anchor main body 1, the anchor main body 1 The resistance to the load that bends the portion 1 is increased. As a result, it is possible to suppress the anchor main body 1 from being bent by the load by the gap (S) between the anchor main body 1 and the hollow shaft 3. Therefore, as compared with the case where the anchor main body 8 fitted in the hollow shaft 10 and the ground 5 are not in direct contact like the conventional anchor, the wire rope is less likely to sag.

  The upper end of the blade 4 of the blade portion 2 is bent at a right angle. In this manner, the rigidity of the blade 4 can be increased by bending the upper end of the blade 4 at a right angle. In addition, since the upper end of the blade 4 can be easily confirmed visually when the blade portion 2 is driven, excessive driving of the blade portion 2 can be prevented. Furthermore, since the upper end of the blade | wing 4 can be easily confirmed visually when the blade | wing part 2 is driven in, the blade | wing part 2 can be driven in easily so that the natural ground surface and the upper end of the blade | wing 4 may correspond. As shown in FIG. 2A, even if the upper end of the blade 4 of the blade portion 2 is bent downward at an acute angle, the upper end of the blade 4 of the blade portion 2 is not bent as shown in FIG. It may be bent in an arc shape downward.

  In order to set up a rock fall protection net on a natural ground inclined by the anchor of the present invention constructed as described above, as in the conventional anchor described above, first, as shown in FIG. An anchor insertion hole 14 is drilled by a rock drill through the layer 13, and then a coagulant such as cement is injected into the anchor insertion hole 14, and the anchor body 1 is inserted into the anchor insertion hole 14 before the coagulant is cured. . Depending on the rock 12, the anchor main body 1 may be directly driven into the rock 12 without opening the anchor insertion hole 14. Next, after the coagulant is cured, the blade portion 2 is fitted into the upper portion of the anchor main body portion 1 protruding from the topsoil layer 13, and the blade portion 2 is driven into the topsoil layer 13 using the anchor main body portion 1 as a guide.

  Thus, if the anchor of this invention is constructed in the natural ground 5, the wire rope 7 will be fixed to the upper end of the anchor main-body part 1 which protruded from the topsoil layer 13 (refer FIG. 5). As a result, the rockfall protection net 6 can be stretched on the inclined ground mountain 5 where there is a risk of rockfall (see FIG. 6).

  As another construction method of the anchor of the present invention, as shown in FIG. 4, first, the blade portion 2 is driven into the topsoil layer 13, and then the anchor main body portion 1 is used as a bedrock by using the hollow shaft 3 of the blade portion 2 as a guide. 12 may be entered.

  According to this method, since the hollow shaft 3 serves as a guide, it is easy to drive the anchor main body 1. In addition, even if it is difficult to drive the blade portion 2 for some reason, since the anchor body portion 1 is not yet fixed, the subsequent response can be easily performed. In addition, when the anchor main-body part 1 is first fixed to the bedrock 12, much effort and time are required for extraction of an anchor.

1: Anchor body part 2: Blade part 3: Hollow shaft 3a: Divided hollow shaft 3b: Projection part 4: Blade 5: Ground mountain 6: Falling rock protection net 7: Wire rope 8: Anchor body part 9: Blade part 10: Hollow Axis 11: Blade 12: Rock 13: Topsoil layer 14: Anchor insertion hole

Claims (7)

  It consists of an anchor main body part and the anchor main body part and a separate wing part, and the wing part consists of a hollow shaft into which the anchor main body part is fitted and a plurality of blades radially fixed to the hollow shaft, The said hollow shaft consists of a some division | segmentation hollow shaft provided at intervals in the axial direction of the said hollow shaft.   The anchor according to claim 1, wherein an upper end of the blade is bent.   The anchor according to claim 2, wherein a bending angle of an upper end of the blade is a right angle.   The anchor according to any one of claims 1 to 3, wherein a protrusion is formed on an outer peripheral surface of the divided hollow shaft.   The anchor according to any one of claims 1 to 4, wherein a lower end of the blade is inclined upward from the inside toward the outside.   The anchor main body is fixed to the natural ground, and then the blade main body is inserted into the anchor main body so that the upper end of the blade coincides with the natural ground surface. The blade portion is composed of a hollow shaft into which the anchor main body portion is fitted and a plurality of blades radially fixed to the hollow shaft, and the hollow shaft is spaced apart in the axial direction of the hollow shaft. An anchor construction method comprising a plurality of divided hollow shafts provided.   The blade portion is driven into the natural ground until the upper end of the blade portion coincides with the surface of the natural ground, and then the anchor main body portion separate from the blade portion is fixed to the natural ground using the blade portion as a guide. The portion includes a hollow shaft into which the anchor main body portion is fitted and a plurality of blades that are radially fixed to the hollow shaft, and the hollow shaft is provided with a plurality of intervals in the axial direction of the hollow shaft. An anchor construction method comprising a plurality of divided hollow shafts.

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