JP2002206235A - Threaded anchorage device for anchor, capable of being mounted in free position - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain ideal yield strength by reducing lateral pressure acting on an anchorage device and a consolidation agent. SOLUTION: The consolidation agent such as an epoxy resin is pressed and infilled from an injection hole 1c into an insertion hole 1a, whereinto an anchor 3 is inserted, of the anchorage device 1, and consolidated within the insertion hole 1a so as to fix the anchorage device 1 to the anchor 3. The favorable yield strength can be obtained by virtue of the absence of the application of the excessive lateral pressure because the taper angle θ of a tapered part 1aT is in the range of 3-10 degrees though the lateral pressure acts on the anchorage device 1 and the consolidation agent due to the pull-out force of the anchor 3 after the anchor 3 is put under tension by a take-up.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anchor plate such as an anchor plate such as a twisted PC steel wire or the like for a stabilization work, a slope stabilization work, or a structure stabilization work. The present invention relates to a screw-type fixing device for an anchor that can be freely attached to a fixing position.

[0002]

2. Description of the Related Art In a shoring work, an anchor is inserted into a hole excavated deep in the ground and fixed with grout material, and the tip of the anchor is fixed to an anchor plate on the surface with a wedge, a bolt and a nut. Has been done.

[0003] In the wedge fixing method, the wedge is fixed to the anchor plate by holding a split wedge at the tip of the anchor and fitting it into a hole of an anchor head fixed to the anchor plate. With the wedge fixing method, a position different from the expected position can be freely fixed according to the situation at the site, as long as the user is nervous for work at the site, and the workability is good.

The screw type fixing system is generally called an apartment type. A screw type fixing device is fixed to the tip of an anchor in advance by crimping at a factory, and the screw type fixing device is inserted through an anchor plate. The anchor is fixed to the anchor plate by being inserted through the hole and screwing the fixing nut. This condominium type is easy to re-tension the anchor and is excellent in terms of maintenance.

However, the wedge fixing method has the following problems. (A) Once anchored, the anchor is scratched by a wedge. (B) The wedge easily slips due to rust. (C) If there is no more than a certain amount of tension, it is difficult to re-tension the anchor with a tension device such as a jack. (D) Adjustment margin is limited even in the ring type in which the outer periphery of the anchor head is threaded, and it is generally difficult to maintain and manage after construction (after fixing).

Further, the screw type fixing system has the following problems. (A) It is difficult to crimp the screw-type fixing device to the anchor at the site, and the screw-type fixing device must be fixed to the anchor at a factory. For this reason, when the length of the previously manufactured anchor is different from the actual effective length after construction, it is necessary to refill the anchor plate and raise the anchor plate, which is troublesome and impairs the appearance. (B) The strength of the fixing tool expected at the beginning cannot be obtained due to the addition or the like. (C) Further, the anticorrosion performance and the anticorrosion structure do not meet the specifications.

Accordingly, the applicant of the present invention first forms a taper-shaped anchor insertion hole which is widened from one end to the other end and which has a rough inner surface. A screw-type fixing device for an anchor that can be freely mounted at an attachment position, in which a male screw to which a fixing nut is screwed is formed, and an injection hole for injecting a consolidating agent such as epoxy resin into the insertion hole is formed on a side of one end of a small diameter. Developed (Japanese Patent Application 2000-34)
0510).

In this new screw fixing device for anchors, an anchor is inserted or inserted from one end of a small diameter into a tapered insertion hole, and a consolidating agent such as epoxy resin is injected from the injection hole into the insertion hole for solidification. By doing so, it is integrally attached to the anchor. Therefore, there is no restriction on the mounting position with respect to the anchor, and the screw fixing device for an anchor can be fixed at the optimum position of the anchor according to the situation at the site. In other words, according to this screw fixing device for anchors,
The advantages of the conventional wedge fixing method and screw type fixing method are utilized, and the disadvantages are eliminated.

[0009]

By the way, in the above-mentioned screw type fixing device for anchors, the tapered shape of the insertion hole and the roughened inner surface improve the binding between the fixing device and the binding agent, thereby increasing the fixing strength. Enhance. However, since the insertion hole is formed over the entire length from one end to the other end,
If the fixing tool is kept at a predetermined thickness and is made to have a certain thickness or more, the taper angle inevitably becomes small, and the pulling force of the anchor becomes a strong lateral pressure, which acts on the fixing tool and the binder. I am dissatisfied.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a screw fixing device for an anchor which can be mounted at any position and which can reduce the lateral pressure acting on the fixing device and the binder to obtain an ideal proof stress.

[0011]

In order to achieve the above object, according to the first aspect of the present invention, an insertion hole through which an anchor is inserted is formed at the center, and a fixing nut is screwed onto an outer peripheral surface. A male screw is formed, and the injection hole is formed on the side of one end. In the screw fixing device for an anchor which can be freely mounted, a plurality of the insertion holes are narrowed as approaching the one end where the injection hole is formed. The tapered portion was formed in such a manner that a step portion was formed between the tapered portions and the tapered portion was continuously provided.

In this means, since the restriction on the taper angle of each of the plurality of tapered portions formed in multiple stages is reduced, the side pressure can be reduced by setting the taper angle large, and a better proof stress can be obtained.

According to the first aspect of the present invention, the taper angle of the tapered portion is 3 to 1.
It can be 0 degrees, preferably 4 to 8 degrees (claim 2). With this configuration, the lateral pressure generated by the pulling force of the anchor does not become excessive, and a good proof stress can be reliably obtained. If the taper angle is smaller than 3 degrees, the lateral pressure becomes excessive and the molding of the casting cannot be reproduced beautifully. If the angle is larger than 10 degrees, the outer diameter of the fixing device becomes large, which is uneconomical, and the wedge effect is hard to change at an angle larger than that.

According to the first or second aspect of the present invention, it is preferable that the ratio of the pitch of the tapered portion to the minimum inner diameter of the tapered portion is 0.8 or more. In this case, the bonding agent such as an epoxy adhesive becomes stronger against deformation and shearing.

[0015]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an embodiment of a screw type fixing device for an anchor according to the present invention, which can be freely mounted. The fixing device 1 is manufactured by forming an insertion hole 1a at the center, forming a male screw 1b on the outer peripheral surface, and forming an injection hole 1c on the side of the lower end.

The insertion hole 1a is for inserting or inserting an anchor 3 such as a stranded PC steel wire from one end side.
A plurality of tapered portions 1aT tapering narrower as approaching the one end where c is formed are formed continuously by forming a step 1aD between them.

Usually, the taper angle θ of the tapered portion 1aT is in the range of 3 to 10 degrees, preferably 4 to 8 degrees. The reason for the above is that if the taper angle θ of the tapered portion 1aT is smaller than 3 degrees, the lateral pressure becomes excessive, the molding of the casting cannot be reproduced beautifully, and if it is larger than 10 degrees, the outer diameter of the fixing tool becomes large. This is because it is uneconomical and the wedge effect is hard to change at an angle larger than this.

The male screw 1d is for screwing the fixing nut 5 of FIG. 2 and is formed as a trapezoidal screw by machining. The injection hole 1c is for injecting a solidifying agent 7 such as an epoxy resin into the insertion hole 1a. As the solidifying agent 7, a mixture of an epoxy compound (base agent) 7a (see FIG. 5), a curing agent 7b, and fibers (not shown) such as glass fiber or carbon fiber is usually used. Epoxy resin which does not mix the above fibers, or other consolidating agents can also be used.

Although the screw-type fixing device 1 for anchors whose mounting position is freely adjustable as shown in the figure is made of casting, it may be manufactured by machining high-strength plastic (such as sintered carbon composite) or steel.

FIGS. 3 to 10 show a fixing device 1 according to the present invention.
Here is an example of using. The anchor 3 is fixed by using the anchor type screw fixing device 1 of FIG. That is, the distal end portion of the anchor 3 inserted into the hole 9 excavated in the ground and fixed with the grout material is washed to remove foreign matters such as moisture, grease, cement, etc. attached to the anchor 3. Then, as shown in FIG. 3, the gap between the steel wires of the anchor 3 is filled with butyl rubber 10 or the like in order to prevent the leakage of the binding agent 7 by closing the portion corresponding to the planned lower end of the fixing device 1.

Next, the tip of the anchor 3 is
Through the insertion hole 1a from the lower end of the injection hole 1c side,
The fixing device 1 is mounted on the anchor 3. After the fixing device 1 is mounted, the hardening of the binder 7 is promoted, and outdoor rain, freezing,
The outer periphery of the fixing device 1 is heated by a heater 11 such as an electric heater for the purpose of improving and stabilizing the working conditions except for bad conditions such as a low temperature that hinders the solidification of the binding agent 7 (FIG. 4). If necessary, the fixing device is degreased with high-pressure high-temperature steam or the like to which an abrasive has been added.

After the completion of the above operation or in parallel with the above operation, as shown in FIG. 5, the epoxy compound 7a, the curing agent 7b and fibers such as glass fiber are mixed at a predetermined ratio by a special mixer 13. It will be referred to as a binding agent 7. In this case, usually, the caking agent 7 for one time is mixed in such a manner that air bubbles which lower the caking strength are prevented from being mixed. The binding agent 7 obtained above is
Immediately, after or after heating, the insertion hole 1a of the fixing device 1
Then, as shown in FIG. 6, the pressure is filled from the injection hole 1c to the upper portion of the insertion hole 1a through the pipe 15 by the caulking gun 14 or the like.

Next, as shown in FIG. 7, a back tube 17 is driven into the opening end of the hole 9 to prevent corrosion, and the end is stopped with a water stopping material 18 such as epoxy resin or hot melt. The anchor plate 20 is attached by inserting the fixing device 1 into the through hole 20a.

After the above operation is completed, as shown in FIG. 8, the fixing nut 5 is screwed to the fixing device 1 and a tension device 22 such as a jack (cylinder) is attached to the anchor plate 20 via the attaching member 23. Then, the coupler 24 is screwed to the male screw 1b of the fixing device 1.

In the above state, the tension device 22 is actuated to pull the anchor 3 through the fixing device 1. When the anchor 3 is tensioned by a predetermined force, the fixing nut 5 is tightened to the anchor plate 20 without loosening. Fix 3 Needless to say, the tensioning of the anchor 3 by the tensioning device 22 is performed after the consolidation of the consolidation agent 7 reaches a practical strength. The operation of the fixing nut 5 is performed through the window hole 23a of the mounting member 23. After the anchor 3 is tensioned, a lateral pressure acts on the fixing device 1 and the binder 7 due to the pull-out force of the anchor 3, but since the taper angle θ of the tapered portion 1a is in the range of 3 to 10 degrees, it is excessive. There is no side pressure, and good yield strength can be obtained.

Then, after the tensioning device 22 and the coupler 24 are removed, as shown in FIG.
Then, a head cap 26 is attached so as to cover the exposed portion of the fixing device 1 and the fixing nut 5, and the space between the head cap 26 and the back tube 17 is filled with rust-preventive oil 27 to complete the fixing operation. Reference numeral 28 denotes a nipple for filling the head cap 26 with the rust-preventive oil 27, and 29 denotes a plug for venting air.

The above-described anchor fixing method can be applied to re-tensioning an existing anchor fixed by a wedge. FIG. 11 shows this example. First, the tensioning device 32 is attached to the anchor plate 20 by the mounting member 3.
The anchor 3 is connected to the tensioning device 32 such as a jack by grasping the tip of one anchor 3 with the steel wire coupler 34.

In the above state, the tension device 32 is operated to pull the anchor 3, and the two wedges 37 are pulled out from the holes (not shown) of the anchor head 38 as shown in FIG. This operation is performed for all the anchors 3, and finally, the anchor head 38 and the tensioning device 32 are removed from the anchor plate 20. The removal of the wedge 37 and the operation of coupling and separating the coupler 34 are performed from the window 33a of the mounting member 33.

Thereafter, the anchor 3 is re-fixed by using the fixing device 1 in the procedure shown in FIGS. Therefore, the anchor fixing structure in the case of re-fixing is the same as that in the case of new fixing (FIG. 9).

In the figure, seven anchors (PC steel stranded wires) 3
(Only two are shown except for FIG. 10), but the number of anchors 3 to be used is arbitrary, and 7
It can be more or less than a book. For reference, the screw-type fixing device 1 for an anchor which can be freely mounted in the figure is shown.
Has a length of 400 mm, a thickness (outer diameter) of 70 mm, a taper angle θ of the tapered portion 1aT of about 7 degrees, a minimum inner diameter of the tapered portion 1aT of 45 mm, a maximum inner diameter of 53 mm, and a step of the step portion 1aD of 4 mm. "= (53mm-45mm) /
2 "", the pitch of the tapered portion is about 36 mm, and the ratio of the pitch of the tapered portion to the minimum inner diameter of the tapered portion is 0.8. However, the present invention is not limited to this. Needless to say, it will be changed. Although the step 1aD in the figure is continuous in the circumferential direction of the insertion hole 1a, it does not have to be continuous. The taper angles θ of all the tapered portions 1aT may or may not be the same. When the ratio of the pitch of the tapered portion to the minimum inner diameter of the tapered portion is 0.8 or more, the epoxy adhesive becomes strong against deformation and shearing. The minimum inner diameter is 33-55
The mm and the step may be about 2 to 3 mm, and the outer diameter and the like are changed so as to satisfy the above conditions.

[0031]

As described above, according to the first aspect of the present invention, an anchor having an excellent free mounting position can be expected in which the lateral pressure on the fixing device and the binder is reduced and more ideal proof stress can be expected. A screw-type fixing device can be provided.

[0032] In the screw fixing device for anchor according to claim 1, the taper angle of the tapered portion is 3 to 1.
When the angle is set to 0 degrees, preferably 4 to 8 degrees, the lateral pressure is reliably reduced, and the fixing device can be more firmly and surely attached.

[0033] In the screw fixing device according to claim 1 or 2, wherein the ratio of the pitch of the tapered portion to the minimum inner diameter of the tapered portion is 0.8 or more, a solidifying agent such as an epoxy adhesive. This has the effect of increasing resistance to deformation and shearing.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a screw-type fixing device for an anchor that can be freely mounted according to the present invention.

FIG. 2 is a cross-sectional view of a fixing nut screwed to the screw-type fixing device for an anchor which can be freely mounted in FIG. 1;

FIG. 3 is a diagram showing an example of attaching butyl rubber to an anchor.

FIG. 4 is a cross-sectional view showing a state in which the anchor fixing screw fixing device of FIG.

FIG. 5 is a diagram illustrating an example of a method of mixing a binder such as an epoxy resin.

FIG. 6 is a cross-sectional view showing an example of injecting a binding agent into an insertion hole of a screw fixing device for an anchor which can be freely attached.

FIG. 7 is a diagram showing an example of a water stopping state by a water stopping material.

FIG. 8 is a view showing an example of a tensioning operation of the anchor.

FIG. 9 is a diagram showing a fixing state of an anchor by the present fixing device.

FIG. 10 is a view showing the relationship between a screw-type fixing device for an anchor according to the present invention, which can be freely mounted, an anchor, and an anchor.

FIG. 11 is a diagram showing an example of removing a wedge from an existing anchor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixing tool 1a Inserting hole 1aD Step 1aT Taper 1b Male screw 1c Injection hole 3 Anchor 5 Fixing nut 7 Binder θ Taper angle

Claims (3)

[Claims] An insertion hole is formed at the center of the insertion hole, and a male screw for screwing a fixing nut is formed on an outer peripheral surface of the fixing member. An anchor screw fixing device for an anchor, wherein the insertion hole has a configuration in which a plurality of tapered portions that narrow as approaching the one end portion where the injection hole is formed are formed continuously by forming a step portion therebetween. A screw-type fixing device for an anchor that can be freely mounted at the mounting position. 2. The fixing device according to claim 1, wherein the taper portion has a taper angle of 3 to 10 degrees, preferably 4 to 8 degrees. 3. The fixing device according to claim 1, wherein the ratio of the pitch of the tapered portion to the minimum inner diameter of the tapered portion is 0.8 or more.