JP2914590B2 - Riser device for grouting anchor body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a riser device for grouting an anchor fixing body (hereinafter referred to as an anchor body) to the ground, and more particularly to an anchor for securing a minimum allowable grouting thickness for the anchor body by a simple mechanism. The present invention relates to a body riser device.

[0002]

2. Description of the Related Art An example of a method for constructing a so-called ground anchor will be briefly described with reference to FIG. The casing 43 is driven into the ground 5 by the drilling machine 42, and the anchor hole 9 is drilled.
Insert grouting hose 44 into casing 43 and grout 7
Inject. Anchor assembly 45 in which anchor material 1 made of steel wire, rope, or steel rod and anchor body 1 are integrally connected.
Is dropped into a predetermined position in the grout 7 surrounded by the casing 43, and then a pressure head 47 is attached to the top of the casing 43, and the grout 7 is injected under pressure. After the grout has solidified, a tension jack 48 is connected to the top of the anchor assembly 45, and the necessary tension is applied to the anchor material.After that, a formwork is arranged around the anchor material and concrete is driven into the building foundation 50 so that the building foundation 50 is formed. After forming and solidifying the concrete, the tension jack 48 is removed to give tension to the solidified concrete of the building foundation 50.

[0003] The force acting on the ground anchor acts as a tensile force or a compressive force on the grout 7 around the anchor body 1 via the anchor material and the anchor body 1, and furthermore, the ground 5
Absorbs this tensile or compressive force. In this case, it is important that the anchor body 1 is firmly and integrally connected to the ground 5, and in order to secure the pull-out resistance and the corrosion resistance of the anchor body 1, the grout 7 around the anchor body 1 is required. It is required that the thickness, that is, the grout cover thickness S (see FIG. 7B) is not less than a required minimum limit.

[0004] With regard to a diagonally installed anchor 1 used for recent building structures (see FIG. 7 (A)), it is standardized that the grout covering thickness S is 2 cm or more over the entire circumference of the anchor 1. I'm in the mood to be.

[0005]

In recent bridges, building structures, and the like, an anchor body 1 fixed diagonally to a ground 5 as shown in FIG. 7A is used. In this case, if the anchor body 1 is held at the center of the anchor hole 9 as shown in FIG. 7 (B), it is possible to secure a uniform grout covering the anchor body 1 and realize a firm fixation to the ground 5. Can be. But,
In reality, a part of the anchor body 1 inserted obliquely is bent downward by its own weight as shown in FIG. 7 (C), and one end comes into contact with the lower surface of the anchor hole 9, and around the anchor body 1 There is a problem that the grout 7 cannot be covered uniformly, and the bonding strength between the anchor body 1 and the ground 5 is insufficient compared with the design value.

In order to solve this problem, as shown in FIGS. 7 (D) and 8, suitable fixed risers 3 are attached to the surface of the anchor body 1 at uniform angular intervals and longitudinal intervals.
The anchor body 1 is arranged concentrically in the anchor hole 9 so that a uniform grout covering can be obtained. However, when the height of the riser 3 in the radial direction of the anchor body 1 is selected to be the required grout covering thickness S, the diameter of the casing 43 for excavating the anchor hole 9 is made one step larger than that without the riser. Therefore, the diameter of the hole drilled in the ground 5 increases, the installation cost of the anchor body 1 increases, and it becomes uneconomical. On the other hand, the height of the riser 3 is set to the required grout cover thickness S.
In the following, not only the grout coverage becomes non-uniform, but also the minimum thickness cannot be ensured. Therefore, fixed risers lack practicality.

As a method for securing the minimum grout covering thickness without increasing the drilling diameter of the ground 5, when the ground 5 is inserted into the casing 43, it does not protrude greatly from the surface of the anchor body 1.
A riser 3 utilizing an elastic force or a frictional force having a structure projecting to a required height S when the casing 43 is pulled out, and a packer-type riser 3 which expands after being inserted into the casing 43 have been proposed. However, in the case of using the elastic force, the riser 3 has a problem that the friction between the anchor body 1 and the casing 43 increases, and the anchor body 1 comes off together when the casing 43 is pulled out. The method using the frictional force not only has a problem that the structure of the riser 3 is complicated and increases the cost, but also lacks the reliability of the operation. The packer type has a problem that the bulging operation becomes unstable when the pressure at the time of injecting the pressurized grout 7 around the anchor body 1 is high as shown in FIG.

Accordingly, an object of the present invention is to provide a grouting riser device for an anchor body which can ensure a minimum grouting thickness without requiring an increase in the diameter of the casing.

[0009]

In the embodiment shown in FIGS. 1 and 2, a riser apparatus for grouting an anchor body according to the present invention is a casing for a drill for drilling an anchor hole.
Locking mechanism 6 with hollow cylindrical outer bit 13 at the tip of 43
(Fig. 3), and the anchor body 1 is attached to the casing.
43 and then can be inserted into the outer bit 13, the wall thickness t of the cylindrical side wall of the outer bit 13 and the allowable minimum grout suffer thickness S _m or more with respect to the anchor body, the said anchor body 1 locking mechanism 6 The structure provided with the unlocking means 29 (FIG. 3) is used.

Another embodiment of the riser apparatus for grouting an anchor body according to the present invention shown in FIGS. 4 and 5 includes a plurality of rigid spheres 36 having a diameter equal to or more than the minimum allowable grout cover thickness Sm for the anchor body 1. Ann linked by an annular string 37
And beads 35 can be circumscribed to the circumference of the car body 1, for example, tether the retaining ring 40 to be fitted to the reduction portion 1a of the tip of the anchor body 1
It is joined to the rosary 35 by 39, and the tying string 39
A bead on the part on the peripheral surface of the anchor body 1 on the rear end side by the length
A configuration in which 35 is circumscribed is used. Preferably, an operation string 38 having substantially the same length as that of the anchor body 1 is connected to the annular string 37, and the length of the annular string 37 is adjusted so that the bead 35
Can be circumscribed on the peripheral surface of the anchor body 1.

[0011]

The intermediate ring 15 and the outer bit 13 in FIG. 2 are the distal end of the casing 43 in FIG. 6, and the bit 13a formed at the distal end of the outer bit 13 acts as a digging blade. As shown in A), excavation is performed to a required depth of the ground 5. The intermediate ring 15 in the figure can be omitted, and the outer bit 13 can be directly connected to the casing 43 by the locking mechanism 6 (see FIG. 3A). The anchor body 1 is inserted into the casing 43, and the tip of the anchor body 1 is
Into the hollow part of. At this time, the unlocking member 29 (see FIG. 3B) provided on the anchor body 1 engages with the lock mechanism 6 between the tip of the casing 43 (the intermediate ring 15 in FIG. 3) and the outer bit 13. And unlock the lock.

Thereafter, as shown in FIG.
Is started, the lock between the end of the casing 43 and the outer bit 13 is unlocked, and the outer bit 13 is inserted into the anchor hole 9 in a state fitted to the end of the anchor body 1. Then, only the casing 43 is pulled out from the anchor hole 9. An outer bit 13 exists between the inner surface of the anchor hole 9 and the tip of the anchor body 1 as shown in FIG.

Since the outer bit 13 is short, a space for injecting the grout 7 over substantially the entire length of the anchor body 1 is formed between the inner surface of the anchor hole 9 and the outer periphery of the anchor body 1, and the space is injected into the space. that grout overburden thickness is obvious that the at least outer bit 13 thickness t or more, the thickness S _m incur the thickness t required allowable minimum grout
Since Aru Elect above, it is possible to secure the wearing grout has a permissible minimum thickness S _m or more thickness in all directions.

Thus, the object of the present invention is to provide "the provision of a grouting riser device for an anchor body which can ensure the minimum grouting thickness without requiring a large casing diameter".

When the rosary 35 of FIG. 4 is used, a reduced portion 1a is provided at the tip of the anchor body 1 and a locking ring connected to the rosary 35 by a tying string 39 as shown in FIG. After fitting the fork 40 and the rosary 35 to the reduced portion 1a, the anchor 1 and the rosary 35 are inserted into the anchor hole 9, preferably while holding one end of the operation cord 38 on the ground. At the time of insertion, the operation string 38 is fed out according to the insertion speed of the anchor body 1 so that the rosary 35 remains on the reduction section 1a. As shown in FIG. 5B, when the operation string 38 of the rosary 35 is gradually pulled up when the casing 43 starts to be pulled out, the rosary 35 is fixed to the anchor 1 as shown in FIG. 5D.
Strain around the outer circumference of By appropriately selecting the length of the tether 39 between the locking ring 40 and the rosary 35, the rosary 35 can be tensioned on the outer periphery of the distal end portion of the anchor body 1. Since the diameter of the rigid sphere 36 forming a bead 35 Aru Elect above the required minimum allowable grout suffer thickness S _m, the outer beads 35 which was tensioned at the tip of the anchor body 1 in FIG. 1 (D) bits 13 and to secure the wearing grout has a permissible minimum thickness S _m or more in thickness as well is clear. Therefore, the embodiment including the beads 35 also achieves the object of the present invention, namely, “providing a grouting riser device for an anchor body that can ensure a minimum grouting thickness without increasing the diameter of the casing”. I do. However, the rosary 35 can also be configured without using the annular string 37, and the operation string 38 and the tying string 39 can be replaced with other connecting means.

[0016]

FIG. 3 shows a locking mechanism 6 for the outer bit 13.
However, the lock mechanism 6 used in the present invention is not limited to this embodiment. In the illustrated example, the casing 43
The intermediate ring 15 is interposed between the outer ring 13 and the outer bit 13, and the locking mechanism 6 between the intermediate ring 15 and the outer bit 13 is shown. A locking mechanism 6 is provided. This intermediate ring 15
1 is for arranging a riser at a longitudinally intermediate portion of the anchor body 1 as shown in FIG. 1C, but is not essential. If the intermediate ring 15 is omitted, a similar locking mechanism 6 is provided between the outer bit 13 and the casing 43.

The lock mechanism 6 will be described with reference to an outer bit.
An outer step 14 is formed by partially shaving the outer periphery at the end of the intermediate ring 15 on the side of the thirteen, and an inner step 16 is formed at the end of the intermediate ring 15 facing the outer step 14. The outer bit 13 is connected to the intermediate ring 15 by overlapping. A ball receiving hole 17 is formed in the outer step portion 14 of the outer bit 13, a chamfered portion 18 is formed at the inner end thereof, and when the ball 19 is pressed against the chamfered portion 18, a part of the ball 19 is inside the outer bit 13. To protrude. A closing member 20 is integrally provided at the outer end of the ball receiving hole 17 to prevent the ball 19 from falling off, and an opening 21 is formed in the center of the closing member 20.

In FIG. 3A, a blind hole 25 is provided at the inner step 16 of the intermediate ring 15 facing the ball receiving hole 17, and a short cylinder member 26 fitted in the blind hole 25 is received by a ball spring 27. It is urged in the direction of the hole 17. The energized short cylinder member 26 is
The ball 19 enters the opening 21 of the closing member 20 integral with the outer bit 13 and presses the ball 19 toward the chamfered portion 18. At this time, since the short cylinder member 26 engages with both the opening 21 of the closing member 20 of the outer bit 13 and the blind hole 25 of the intermediate ring 15, the outer bit 13 is connected to the intermediate ring 15. Obviously, the outer bit 13 can be fitted into this coupling position while pushing the short tube member 26 against the spring 27 into the blind hole 25 with a finger or the like.

The unlocking member 29 in the illustrated example is an annular projection formed integrally with the anchor body 1. This unlocking member 29 is shown in FIG.
(B), the ball 19 is pushed back in the direction of the blind hole 25 against the spring 27 so that the short cylinder member 26 is closed.
Take out 20. Accordingly, the locking by the short cylinder member 26 is released, the locking mechanism 6 is released, and the outer bit 13 is separated from the intermediate ring 15.

The embodiment of FIG. 4 connects three sets of rosary
5 (A) and 5 (B) show an embodiment combined with FIG.
5 shows the order in which these beads 35 are attached in a state of being circumscribed on the surface of the anchor body 1 as shown in FIGS. 5 (C) and 5 (D). The riser apparatus for grouting the anchor body of the present invention using the beads 35 has only to have at least one set of beads 35, and is not limited to the three-piece beads 35 embodiment.

[0021]

As described [Effect Invention above in detail, grout suffer riser apparatus anchor body according to the present invention, the outer bit 13 or the thickness suffers thereof has a wall thickness of at least the thickness S _m overburden required allowable minimum grout since forming the riser 3 by beads 35 consisting of a rigid sphere 36 having a diameter greater than S _m is, it exhibits the following remarkable effects.

[0022] (1) can be secured suffer allowable minimum thickness S _m or more uniform grout. (2) The structure is simple and can be provided at low cost. (3) it is possible to ensure thickness S _m overburden allowable minimum grout without upgrade of the casing diameter.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an example of an outer bit used as a riser.

FIG. 3 is an explanatory view of a lock mechanism and an unlocking member.

FIG. 4 is an explanatory diagram of an example of a rosary used as a riser.

FIG. 5 is an explanatory diagram of how to use a rosary.

FIG. 6 is an explanatory view of an anchor body installation method.

FIG. 7 is an explanatory view of a grout cover and a riser device of an anchor body.

FIG. 8 is an explanatory view of a conventional anchor body center riser.

[Explanation of symbols]

 1: Anchor body 3: Riser 5: Ground 6: Lock mechanism 7: Grout 9: Anchor hole 10: Drill device 13: Outer bit 14: Outer step 15: Intermediate ring 16: Inner step 17: Ball receiving hole 18: chamfered part 19: ball 20: closing member 21: opening 25: blind hole 26: short cylinder member 27: spring 29: unlocking member 35: bead 36: rigid ball 37: annular string 38: operation string 39: connecting String 40: Locking ring 42: Drilling machine 43: Casing 44: Injection hose 45: Anchor assembly 47: Pressurizing head 48: Tension jack 50: Building foundation

Claims (3)

(57) [Claims] An outer bit is detachably attached to a tip of a drill for drilling an anchor hole, and the separated outer bit can be fitted concentrically to a tip of an anchor body as a riser, and a radius of the outer bit is provided. Is larger than the radius of the anchor body by more than the required grouting thickness. 2. A hollow cylindrical outer sleeve is provided at the end of the casing.
The bit is attached by a lock mechanism to form a drill for drilling an anchor hole, the anchor body can be inserted into the casing and the outer bit, and the thickness of the cylindrical side wall of the outer bit is set to a minimum allowable grout covering thickness for the anchor body. And a grouting device for grouting the anchor body, wherein the anchor body is provided with unlocking means for the locking mechanism. 3. A plurality of rigid spheres having a permissible minimum grout suffer thickness or diameter for the anchor member and circumscribing possible rosary body on the peripheral surface of the anchor body and connected by an annular strap, the reduction of the tip of the anchor body connect the locking ring that fits into the rosary body
Connected with a string, and the rear end from the reduced portion by the length of the connecting string
The grouting riser device for the anchor body , wherein the rosary is circumscribed to a portion on the peripheral surface of the anchor body on the side.