JP6057417B2 - Ground anchor head structure - Google Patents

Description

  The present invention relates to a ground anchor, and more specifically, a ground anchor head structure that applies tension force from the ground side to a tension support member (tendon) whose tip is fixed in the ground and holds the upper end of the tendon. Relates to the head cap.

When the installation period of the ground anchor is prolonged, deterioration of the anchor head and the back of the head becomes a problem. When the anchor head and the back of the head deteriorate, the tendon on which the tension is applied is not sufficiently held on the ground side, and it may be difficult to maintain the supporting force of the ground anchor.
For example, a tendon made of stranded steel wire has corrosion resistance secured by a sheath at its free length, but the sheath is located above (in the direction away from the ground) the anchor plate that is the bearing member. Not present and tendon is exposed. For this reason, tendon in the region near the anchor head is likely to be corroded and deteriorated.
Therefore, if the site worker can visually recognize the state of the tendon in the vicinity of the anchor head, it can be easily determined whether or not the anchor head and the back of the head have deteriorated.

However, in the conventional structure of the anchor head, the state of the tendon in the vicinity of the anchor head could not be confirmed unless the tension acting on the tendon is released and the anchor head and the tendon are fixed.
Therefore, even when a healthy anchor head and head rear structure that has not deteriorated are to be determined, it must be disassembled once to release the tension acting on the tendon. After the determination, it is necessary to apply tension to the tendon again with a jack or the like. And disassembling a healthy anchor head and head back structure that has not deteriorated to release the tension acting on the tendon, and then exerting the tension again on the tendon consumes a great deal of labor and cost. become.
Moreover, since the surplus length of the tendon is so short that the tension cannot be released in many cases, it was not possible to investigate the soundness of the back surface of the ground anchor head.

On the other hand, the present applicant previously provided a technique that can visually recognize (or visually) the state of the anchor head and the back of the head, in particular, the state of the tendon immediately below the anchor head (Patent Document 1,). Patent Document 2).
According to the related arts (Patent Document 1 and Patent Document 2), since the tendon in the region immediately below the anchor head can be visually recognized, the anchor head and the head back structure are disassembled, and the tension acting on the tendon is reduced. Even if it is not released, it is possible to easily and accurately determine the tendon state immediately below the anchor head where corrosion and deterioration are likely to proceed. Then, as a result of visual recognition, only the anchor head and the back of the head structure that are judged to have deteriorated or corroded can be disassembled to release the tension of the tendon, and the necessary parts replacement and repair can be performed. I can do it.
However, in the related arts (Patent Document 1 and Patent Document 2), although the tendon state in the area immediately below the anchor head can be visually recognized, the area above the anchor head cannot be visually recognized.

Japanese Patent No. 4793952 Japanese Patent No. 4793955

  The present invention has been proposed in view of the above-described problems of the prior art, and it is not necessary to disassemble the anchor head and the head back structure of the ground anchor, and the tendon in the region above the anchor head is not required. An object of the present invention is to provide a ground anchor head structure in which the state can be easily visually recognized (visually).

According to the present invention, the tension support member (11), an anchor head bearing capacity plate for supporting the tension acting on the tension support member (11) and (3) to secure the vicinity of the upper end of the tension support member (11) and (7), and a head cap which is located above the Bearing plate (3) (4A), the head cap (4A) includes a head cap body (41A), said head cap body ( a confirmation window portion extending in the vertical direction of 41A) and (42O), the confirmation window (42O) is fixed to the head cap body consists of a transparent resin (41A) In the ground anchor head structure , the head cap body (41A) is made of aluminum, and the head cap body (41A) is provided with an opening (41Oa) into which the confirmation window part (42O) is fitted. The head cap The body (41A) is provided with a pair of window frame members (48) for mounting the confirmation window portion (42O), and a flange (41Oa) formed on the entire outer periphery of the confirmation window portion (42O). Is sandwiched between the window frame member (48) and the region (50C, 50D) in the vicinity of the opening (41Oa) and fixed by a stud bolt (49).

Then, according to the present invention, it is fixed to the tension support member (11), Bearing plate for supporting the tension acting on the tension support member (11) and (3), the vicinity of the upper end of the tension support member (11) an anchor head (7), and a head cap which is located above the Bearing plate (3) (4A), the head cap (4A) includes a head cap body (41P), said head cap a confirmation window portion extending in the vertical direction of the body (41P) and (42P), the confirmation window (42P) is fixed to the head cap body consists of a transparent resin (41P) In the ground anchor head structure , the head cap main body (41P) is made of aluminum, and the window attaching portions (50E, 50F) of the head cap main body (41P) include a confirmation window portion (42P). ) Peripheral edge (42Ps) Slidably groove for engagement (41Pd) is formed, the upper end of the check window portion (42P) is fixed by the check window engaging member (41Pt) and stud bolts (49).

According to the present invention having the above-described configuration, the portion inside the head cap (4) from the confirmation window (42), that is, the portion above the anchor head (7) can be visually observed. Without removing the cap (4), the reduction, breakage, corrosion, etc. of the rust preventive agent (grease) in the head cap (4) can be visually confirmed. Therefore, maintenance of the ground anchor can be performed reliably.
And, when there is no problem in the head cap (4), it is not necessary to perform an inefficient work of removing the head cap (4) and inspecting. Can be implemented economically. Moreover, even when the tendon has a short extra length and tension cannot be released, the soundness investigation of the ground anchor head back surface can be easily and reliably performed.

Here, only by forming a transparent safety window on the head cap (4), when a rust inhibitor (grease) is injected into the head cap (4) at a high pressure, the pressure of the injected grease A gap is formed between the transparent safety window and the head cap body (41), and the rust inhibitor may leak out from the gap.
In the present invention, the head cap body (41) is made of resin (for example, polyethylene), and the peripheral edge portion (42a) of the confirmation window portion (42) is cast with the head cap body (41). If a labyrinth seal is formed on the peripheral portion (42a) of the confirmation window portion (42) cast into (41), the transparent safety window and the head cap body (41) are formed by the pressure of the injected grease. Even if a gap is formed between them, grease is prevented from leaking out of the head cap (4) by the sealing action of the labyrinth seal.
Alternatively, in the present invention, the head cap body (41A) is made of metal (for example, aluminum), and the peripheral portion (42Aa) of the confirmation window portion (42A) is connected to the head cap body (rivet, bolt, etc.) by a fastening member (rivet, bolt, etc.). 41A), no gap is formed between the transparent safety window (42A) and the head cap body (41A) even when the pressure of the injected grease is applied. Leaking out of the cap (4A) is prevented.

It is explanatory drawing which shows an example of the ground anchor to which embodiment of this invention is applied. It is a front view of the head cap used in 1st Embodiment of this invention, and is a figure which attach | subjects and hatches a confirmation window part. It is a top view of the head cap used in a 1st embodiment. FIG. 3 is a front view similar to FIG. 2, but showing a state in which a confirmation window is transparent and a tendon inside the cap and a part of the anchor head are visible. FIG. 4 is a sectional view taken along line AA in FIG. 3. It is a fragmentary sectional view which shows the vicinity part of the confirmation window part in the BB line cross section of FIG. It is an enlarged reference view showing a problem when the confirmation window is simply cast. It is a fragmentary sectional view which shows the principal part of the 1st modification of 1st Embodiment in the BB sectional view of FIG. It is a fragmentary sectional view which shows the principal part of the 2nd modification of 1st Embodiment in the BB sectional view of FIG. It is a fragmentary sectional view which shows the principal part of the 3rd modification of 1st Embodiment in the BB sectional view of FIG. It is a fragmentary sectional view which shows the principal part of the 4th modification of 1st Embodiment in the BB sectional view of FIG. It is a front view of the head cap used by 2nd Embodiment of this invention, and is a figure which attach | subjects and hatches a confirmation window part. It is a top view of the head cap used in 2nd Embodiment. FIG. 13 is a first modification of the second embodiment, and is a partial cross-sectional view showing a vicinity of a confirmation window in the cross section taken along line BB in FIG. 12. FIG. 13 is a first modified example of the second embodiment, and is a partial front view showing a part near the upper part of the confirmation window part of FIG. It is a fragmentary sectional view which shows the principal part of the 2nd modification of 2nd Embodiment in the BB sectional view of FIG. It is a partial front view which partially fractures and shows the upper part vicinity of the confirmation window in the 2nd modification of 2nd Embodiment. It is a fragmentary sectional view which shows the principal part of the 3rd modification of 2nd Embodiment in the BB sectional view of FIG. It is a partial front view which partially fractures and shows the upper part vicinity of the confirmation window in the 3rd modification of 2nd Embodiment. It is process drawing which shows 1 process of attaching the confirmation window part in the 3rd modification of 2nd Embodiment to a head cap main body. FIG. 21 is a process diagram illustrating a process continued from FIG. 20. FIG. 22 is a process diagram illustrating a process continued from FIG. 21. It is front sectional drawing which shows 3rd Embodiment of this invention. It is a front view which shows 3rd Embodiment. It is front sectional drawing which shows 4th Embodiment of this invention. It is a front view which shows 4th Embodiment.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
First, a ground anchor to which the first embodiment is applied will be described with reference to FIGS.
FIG. 1 shows a ground anchor with a head cap. In FIG. 1, a ground anchor denoted by reference numeral 101 as a whole is provided with an anchor plate 3 on a frame (for example, a concrete frame) 10, and a through hole 3 </ b> H is formed at the center of the anchor plate 3.
On the upper surface of the anchor plate 3, an anchor head support member 2 having a cylindrical shape as a whole is placed. The anchor head support member 2 is provided with a visual window 2w, and the tendon 11 in the region immediately below the anchor head 7 can be visually recognized through the visual window 2w.

For example, a plurality of tendons 11 (tension support members) made of steel strands extend through the anchor plate 3 in the vertical direction through the through holes 3H of the anchor plate 3. Although not clearly shown, the vicinity of the upper ends of the plurality of tendons 11 is fixed to the anchor head 7 using a known fixing means.
Although not shown, the lower end of the tendon 11 is constrained. A tension force is applied to the tendon 11 by applying a tensile force to the upper end of the tendon 11 with a jack (not shown).

The head cap 4 in the ground anchor 101 shown in FIG. 1 is shown in FIGS.
2 and 3, the head cap 4 has a head cap body 41 and a confirmation window 42 extending in the vertical direction of the head cap body 41. The confirmation window 42 is made of a transparent resin (for example, Polycarbonate) and glass.
At the top of the head cap body 41, an air vent 43 for venting air inside the cap is provided.
A flange 41a is formed at the lower end of the head cap body 41, and a plurality of bolt holes (four locations in the illustrated example) 41b are formed in the flange 41a. A planting bolt B (see FIG. 1) is inserted into the bolt hole 41b, and the head cap 4 is fixed to the anchor head support member 2 by the planting bolt B.

The confirmation window portion 42 is provided with a nipple (grease nipple) 44 for filling the cap 4 with a rust preventive agent (or lubricant: for example, grease).
Although not explicitly shown, a nipple support member (not shown) is embedded in a transparent resin (for example, polycarbonate) constituting the confirmation window 42, and a female screw is formed on the nipple support member. Is screwed with a male screw (not shown) formed on the grease injection nipple 44. Thus, the grease injection nipple 44 is disposed through the confirmation window 42.

Here, the AA arrow cross section of FIG. 3 is shown in FIG. FIG. 4 shows a state where the inside of the head cap 4 is seen through the confirmation window 42. 6 shows a part of the cross section taken along the line BB in FIG. 2, more specifically, a region near the confirmation window 42.
As shown in FIG. 6, a substantially T-shaped projection 42 a is formed on the peripheral edge of the confirmation window 42, and the confirmation window 42 is embedded in the head cap body 41 by the projection 42 a (so-called “casting” Fixed).
In the first embodiment, the head cap main body 41 is made of resin (for example, polyethylene), and the protrusions 42a at the peripheral edge of the confirmation window 42 are cast into the head cap main body 41 to form a substantially T-shaped protrusion. A labyrinth seal is formed on the peripheral edge of 42a.
Instead of configuring the peripheral portion of the confirmation window 42 so that a labyrinth seal is formed, a sealing material (for example, a liquid seal or an adhesive) may be applied.

According to 1st Embodiment of FIGS. 2-6, as shown in FIG. 6 in particular, the substantially T-shaped protrusion 42a in the peripheral part of the confirmation window part 42 is cast in the head cap main body 41. As shown in FIG. . The substantially T-shaped protrusion 42a cast into the head cap body 41 is not a quadrangle with a simple cross-sectional shape.
As shown in FIG. 7, when the portion 42as in which the confirmation window 42 is cast into the head cap body 41 is formed in a simple protrusion shape having a square cross section, a rust preventive agent (for example, grease) is applied at a high pressure. When filling, the peripheral edge of the portion 42as where the confirmation window portion 42 is cast into the head cap body 41 is expanded to form a gap, and the rust preventive agent leaks out of the head cap 4 from the gap. There is a risk.

On the other hand, as shown in FIG. 6, if a portion (protrusion) 42 a in which the confirmation window 42 is cast into the head cap body 41 is configured in a substantially T shape, the grease is filled at a high pressure. Even when the peripheral portion of the cast-in projection 42a is expanded to form a gap, the gap is formed along the substantially T-shaped projection 42a of the confirmation window 42 to form a labyrinth seal. To do.
Therefore, the rust preventive agent is prevented from leaking out of the head cap 4 from the peripheral edge of the substantially T-shaped protrusion 42a.

However, in the case shown in FIG. 7, even if the cross section of the portion (projection) 42as in which the confirmation window 42 is cast into the head cap body 41 is a quadrangle, a liquid seal is formed on the projection 42as (protrusion having a square cross section). If an adhesive having a high waterproof performance is applied, it is possible to prevent the grease from leaking from the gap into the square section of the cast-in cross section even when the grease is filled at a high pressure.
In other words, even in the case shown in FIG. 7, if the confirmation window portion 42 applies a liquid seal to the protrusion 42 as cast in the head cap body 41, or applies an adhesive with high waterproof performance, It is possible to obtain the same effect as the first embodiment of the present invention.

FIG. 8 shows a first modification of the first embodiment.
In the first embodiment of FIGS. 1 to 6, the protrusion 42 a in which the confirmation window 42 is cast into the head cap body 41 is configured in a substantially T shape (see FIG. 6). In the first modified example, the cast-in protrusion 42ab in the confirmation window portion 42B is configured in a substantially L shape bent downward in FIG. 8 (outward in the radial direction of the cap body 41).
Even if the portion 42ab in which the confirmation window portion 42B is cast into the head cap body 41 is substantially L-shaped, the peripheral portion of the projection 42ab is filled with a rust preventive agent (for example, grease) at a high pressure. When a gap is formed in the gap, the gap forms a labyrinth seal.
Therefore, the rust preventive agent is prevented from leaking out of the head cap 4.
Other configurations and operational effects in the first modification of FIG. 8 are the same as those of the first embodiment of FIGS.

FIG. 9 shows a second modification of the first embodiment.
9, in the second modification of the first embodiment, the protrusions 42ac on the left and right side portions of the confirmation window portion 42C are semicircular so as to curve downward (outward in the radial direction of the cap body 41) in FIG. It is configured in a curved shape.
Other configurations and operational effects in the second modified example of FIG. 9 are the same as those of the embodiment of FIGS.

FIG. 10 shows a third modification of the first embodiment.
In FIG. 10, in the third modification of the first embodiment, the protrusion 42ad in the confirmation window 42D is such that the tip of the substantially L-shaped protrusion 42ab in FIG. 8 further returns to the confirmation window 42D side. It is bent at a right angle.
Other configurations and operational effects in the third modified example of FIG. 10 are the same as those in the embodiments of FIGS. 1 to 6, 8, and 9.

FIG. 11 shows a fourth modification of the first embodiment.
In the fourth modified example, a portion 42ae in which the confirmation window 42E is cast into the head cap body 41 is formed in a substantially semicircular shape. Therefore, similarly to the case shown in FIG. 7, when the grease is filled at a high pressure, the portion 42 ae in which the confirmation window 42 </ b> E is cast into the head cap body 41 is expanded to form a gap, and the gap Does not form a labyrinth seal, so the rust inhibitor may leak out of the head cap.
Therefore, as in the case of FIG. 7, a liquid seal is applied to the substantially semicircular portion 42 ae in which the confirmation window 42 E is cast in the head cap body 41, or an adhesive having a high waterproof performance is applied. ing.
Other configurations and operational effects in the fourth modified example of FIG. 11 are the same as those of FIG.

Next, a second embodiment of the present invention will be described with reference to FIGS.
In the first embodiment described with reference to FIGS. 1 to 11 and its modification, the head cap body 41 is formed of a resin such as polyethylene, for example. However, in consideration of use in a cold region, the head cap body 41 can be made of metal (for example, aluminum).
In the second embodiment shown in FIGS. 12 and 13, the head cap body 41A of the cap 4A is made of aluminum.

As described above, the head cap body 4A shown in FIGS. 12 and 13 is made of aluminum, and a grease injection nipple 44 is provided at a location 41As that is different from the confirmation window portion 42A (region on the side surface side of the cap body 41A). The male screw is arranged.
Although not clearly shown in FIGS. 12 and 13, a female screw hole (not shown) that engages with the male screw of the grease injection nipple 44 is formed by tapping at a location 41 As different from the confirmation window portion 42 </ b> A. . The male screw of the grease injection nipple 44 is screwed into the female screw hole.
The female screw hole cannot be tapped in the transparent resin (for example, polycarbonate) constituting the confirmation window portion 42A. On the other hand, tapping can be applied to the head cap body 4A made of aluminum. Therefore, in FIGS. 12 and 13, the grease injection nipple 44 is provided at a location different from the confirmation window portion 42A.

Here, when the head cap main body 41 is made of resin, as shown in FIGS. 6 and 8 to 11, the peripheral portions 42 a (42 ab, 42 ac, 42ad) can be cast into the head cap body 41.
However, when the head cap body is made of aluminum, the peripheral edge of the confirmation window cannot be cast into the head cap body.
On the other hand, in the second embodiment shown in FIGS. 12 and 13, the confirmation window portion 42 </ b> A is not cast into the head cap body 41 </ b> A, for example, using the countersunk screw 45 and the nut 46. The peripheral edge of 42A is fixed to the head cap body 41A (the opening thereof).

In the second embodiment of FIGS. 12 and 13, the confirmation window portion is fixed to the head cap body 41 </ b> A (opening thereof) by fixing the peripheral portion of the confirmation window portion 42 </ b> A using, for example, a countersunk screw 45 and a nut 46. 42A is integrated with the head cap body 41A.
Therefore, when a rust preventive agent (for example, grease) is filled at a high pressure, as shown in FIG. 7, the portion where the confirmation window portion 42A is cast into the head cap body is expanded and a gap is formed at the peripheral portion. Never formed. And it is prevented that a rust preventive agent leaks out of the head cap 41A.

  Other configurations and effects in the second embodiment of FIGS. 12 and 13 are the same as those of the first embodiment of FIGS.

14 and 15 show a first modification of the second embodiment.
In the second embodiment of FIGS. 12 and 13, the confirmation window portion 42 </ b> A is fixed to the head cap body 41 </ b> A using a countersunk screw 45 and a nut 46. On the other hand, in the first modification of the second embodiment shown in FIGS. 14 and 15, the confirmation window 42N is fixed to the head cap body 41N by the shaft-like fastening member 45A and the nut 46 via the washer 47. It is a form.
Instead of using the shaft-like fastening member 45A, the washer 47, and the nut 46, the confirmation window portion 42N may be directly fixed to the head cap body 41N with rivets.
Although not clearly shown in FIGS. 14 and 15, the metal washer 47 is tapped without using the nut 46, and the transparent resin plate constituting the confirmation window 42 </ b> N is replaced with the shaft-like fastening member 45 </ b> A and the washer. 47 can be fixed.

16 and 17 show a second modification of the second embodiment.
16 and 17, a rectangular opening 41Oa is provided in a part of the head cap body 41O, and a confirmation window 42O is fitted into the opening 41Oa. And the flange 42Of is formed in the outer periphery perimeter of the confirmation window part 42O.
The flange 42Of is sandwiched between a region near the opening 41Oa of the head cap body 41O and the window frame member 48. From the outer side in the radial direction of the cap 4A (downward in FIG. 16), the head cap body is It is fixed with respect to 41O.

Here, in the second embodiment, since the head cap main body 41O is made of aluminum, a female screw hole to be screwed into the stud bolt 49 can be formed by tapping (in the head cap main body 41O).
Other configurations and operational effects in the first modified example of FIGS. 16 and 17 are the same as those of the second embodiment of FIGS.

18 to 22 show a third modification of the second embodiment.
In the third modified example, the confirmation window 42P is not cast into the head cap body 41P, but the peripheral edge 42Ps of the confirmation window confirmation window 42P is a groove 41Pd formed in the head cap body 41P. (FIGS. 18, 20, and 21).
As shown in FIGS. 18 and 19, the peripheral edge 42Ps of the confirmation window 42P is engaged with a groove 41Pd formed in the head cap body 41P. And the peripheral part 42Ps is comprised so that the inside of the said groove part 41Pd may slide to the up-down direction of FIG. 19 in the state engaged with the groove part 41Pd.

As shown in FIG. 19, above the head cap body 41P, the upper end of the confirmation window portion 42P is locked to the head cap body 41P by a confirmation window portion locking member 41Pt and a stud bolt 49.
Here, the confirmation window portion locking member 41Pt engages with the peripheral edge portion 42Ps in the upper portion of the confirmation window portion 42P, and locks the confirmation window portion 42P to the head cap body 41P.

The procedure for attaching the confirmation window 42P to the head cap body 41P is shown in FIGS.
As shown in FIG. 20, the confirmation window portion locking member 41Pt of the head cap body 41P is separated at the boundary line S shown in FIG.
Next, as shown in FIG. 21, with the confirmation window portion locking member 41Pt separated, the peripheral portion 42Ps of the confirmation window portion 42P (the transparent resin component constituting it) is engaged with the groove portion 41Pd of the head cap body 41P. The confirmation window 42P is inserted while sliding.

Then, as shown in FIG. 22, in the state where the transparent resin component constituting the confirmation window portion 42P is inserted into the groove portion 41Pd of the head cap body 41P, the confirmation window portion locking member 41Pt is moved to the confirmation window portion 42P (transparent resin component). ) And a confirmation window portion locking member 41Pt is fixed to the head cap body 41P with a stud bolt 49 (see FIG. 19).
Although not shown, in the head cap main body 41P, a female screw hole to be screwed with the stud bolt 49 is tapped at a portion corresponding to the stud bolt 49.

  Other configurations and operational effects in the second modified example of FIGS. 18 to 22 are the same as those of the embodiment of FIGS.

23 and 24 show a third embodiment of the present invention.
23 and 24, the anchor plate 3 is placed on the upper surface of the concrete frame 10, the anchor head support member 2A is provided on the anchor plate 3, and the head cap 4 is provided on the anchor head support member 2A. Is attached. The head cap 4 is as described with reference to FIGS.
Here, the anchor head support member 2A is configured by a cylindrical portion 2Aa and a flange 2Af fixed to the upper end of the cylindrical portion 2Aa, and a rear surface viewing window (viewing window) 2Aw is formed.

According to 3rd Embodiment of FIG. 23, FIG. 24, the presence or absence of corrosion of a head back surface can be confirmed by visually inspecting the head back surface of the ground anchor 103 through the visual window 2Aw. At the same time, it is possible to visually check the decrease in the rust preventive agent (grease) in the head cap 4 and the damage or corrosion in the head cap 4 through the confirmation window 42.
As a result, the ground anchor can be maintained safely and economically.
Other configurations and operational effects in the third modified example of FIGS. 23 and 24 are the same as those of the first embodiment of FIGS.

25 and 26 show a fourth embodiment of the present invention.
As shown in FIG. 25, the anchor plate 3 is provided on the pressure receiving plate 12 made of a plurality of members, the anchor head 7 is provided on the anchor plate 3, and the head cap 4 is put on the anchor head 7.
The cylindrical portion 12O below the pressure receiving plate 12 is provided with a viewing window 12w for viewing the back of the head. And the head cap 4 is what was demonstrated with reference to FIGS. 1-22, and the confirmation window part 42 is formed.

Also in the fourth embodiment of FIGS. 25 and 26, it is possible to confirm the presence or absence of corrosion on the back surface of the head of the ground anchor by visually observing the portion below the anchor head 3 through the viewing window 12w. . At the same time, the reduction, breakage, corrosion, etc. of the rust preventive agent (grease) in the head cap 4 can be visually confirmed through the confirmation window 42.
As a result, the ground anchor can be maintained safely and economically.

It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.
In the present specification, the term “ground anchor” is used to include a lock bolt.

2 ... Anchor head support member 3 ... Anchor head 4 ... Head cap 7 ... Anchor head 11 ... Tendon 41 ... Head cap body 42 ... Confirmation window 43 ... Air bleeding part 44 ... Nipple

Claims (2)

A tension support member (11), Bearing plate for supporting the tension acting on the tension support member (11) and (3), an anchor head (7) for fixing the vicinity of the upper end of the tension support member (11), wherein and a head cap (4A) located above the Bearing plate (3), the head cap (4A) includes a head cap body (41A), in the vertical direction of the head cap body (41A) has extending check window portion and (42O), the confirmation window (42O) in the ground anchor head structure is secured to the head cap body consists of a transparent resin (41A) The head cap body (41A) is made of aluminum, and the head cap body (41A) is provided with a pair of window frame members (48) for attaching the confirmation window portion (42O). And the confirmation window 42O) the flange (41Oa) formed on the entire outer periphery is sandwiched between the window frame member (48) and the region (50C, 50D) in the vicinity of the opening (41Oa) and fixed by the stud bolt (49). Ground anchor head structure characterized by A tension support member (11), Bearing plate for supporting the tension acting on the tension support member (11) and (3), an anchor head (7) for fixing the vicinity of the upper end of the tension support member (11), wherein and a head cap (4A) located above the Bearing plate (3), the head cap (4A) includes a head cap body (41P), in the vertical direction of the head cap body (41P) has extending check window portion and (42P), the confirmation window (42P) in the ground anchor head structure is secured to the head cap body consists of a transparent resin (41P) The head cap main body (41P) is made of aluminum, and the window mounting portions (50E, 50F) of the head cap main body (41P) are provided with a peripheral portion (42Ps) of the confirmation window portion (42P). Groove that engages slidably 41Pd) is formed, the ground anchor head structure upper end, characterized in that it is fixed by the check window engaging member (41Pt) and stud bolts (49) of the check window portion (42P).

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