JP2019157476A - Ground anchor head protection and maintenance mechanism - Google Patents

Abstract

To provide a ground anchor head protection and maintenance mechanism capable of easily observing the state of the ground anchor while reliably preventing corrosion at the ground anchor head.SOLUTION: A ground anchor head protection and maintenance mechanism (10) according to the present invention has a hollow shaped base (1), and a top portion (2) in which a peep window (2A: top peep window) is formed on a top surface and a transparent member (22: acrylic, for example) is fitted radially inward. A hollow portion of the base (1) is not filled with a rust preventive material (grease, for example).SELECTED DRAWING: Figure 1

Description

The present invention relates to a head protection and maintenance management mechanism for a ground anchor that surrounds the head of a ground anchor or the vicinity thereof and prevents intrusion of rainwater, groundwater, and the like.
In the present specification, the head protection and maintenance mechanism for ground anchors may be referred to as “head protection and maintenance mechanism”.

Various things, such as the water stop member currently disclosed by patent document 1, are proposed as a water stop member for ground anchors which prevents the penetration | invasion of rain water etc. to a ground anchor head.
In the water-stopping member for ground anchor in the prior art, a cover-like member surrounding the ground anchor head (for example, the head cap in Patent Document 1) is filled with a rust preventive material such as grease, and groundwater or the like Reaching the ground anchor head was prevented. However, when the rust preventive material (for example, grease) is washed away from the water stop member due to groundwater pressure or the like, the washed rust preventive material contaminates the environment of the site where the ground anchor is installed.
Here, depending on the state of the construction site, there are not a few cases where groundwater or the like does not reach the ground anchor head, and there is no possibility that the ground anchor head corrodes even without filling with a rust preventive material.

If the anticorrosive material filled in the internal space of the water-stopping member (the internal space of the cover-like member surrounding the ground anchor head: the space in the head cap 8 in Patent Document 1) flows out, It is necessary to fill with rust preventive material.
However, for example, in the water-stop member disclosed in Patent Document 1, it is impossible to observe the state of the rust preventive material in the head cap from the outside, and the head cap is anchored for each of a number of anchors. It was necessary to remove it from the plate (bearing plate), and therefore it took a lot of time and labor to check the ground anchor head.

Japanese Patent Laying-Open No. 2015-10354

  The present invention has been proposed in view of the above-described problems of the prior art, and it is possible to reliably prevent corrosion at the ground anchor head and to easily observe the state of the ground anchor. It aims to provide protection and maintenance mechanism.

The ground anchor head protection and maintenance mechanism (10) according to the present invention includes:
A hollow base (1);
A peep window (2A: top peep window) is formed on the top surface or on either side, and has a top (2) in which a transparent member (22: for example, acrylic: transparent disk-shaped member) is fitted inward in the radial direction. And
The hollow portion of the base (1) is not filled with a rust preventive material (for example, grease),
A rust preventive material injection mechanism (13: for example, a grease nipple) is provided.
In the head protection and maintenance mechanism (10) of the present invention, after attaching to the ground anchor (30) head (for example, the pressure receiving plate 32) (when water enters the ground anchor head), the base (1) It can be configured so that a rust preventive material is filled in the hollow portion.

According to the present invention having the above-described configuration, the head protection and maintenance mechanism (10) is not filled with a rust preventive material. Unless it is confirmed that water has entered the maintenance mechanism (10) or the head of the ground anchor (30), the rust preventive material is not filled into the head protection and maintenance mechanism (10). If the head protection and maintenance mechanism (10) is not filled with a rust prevention material, the rust prevention material will not flow out of the head protection and maintenance mechanism (10) and contaminate the surrounding environment.
On the other hand, when groundwater enters the head of the ground anchor (30) through the surface of the sheath or the tensile material (31), the intrusion of water is confirmed by viewing from the observation window (2A: top observation window). it can.

According to the present invention, after injecting the rust preventive material into the head protection and maintenance mechanism (10), the rust preventive material has been washed away or visually prevented by visually recognizing from the view window (2A: top view window). It is possible to easily and accurately confirm that the rust material has changed color. Unlike the prior art, it is not necessary to remove the head cap from the pressure receiving plate every time it is confirmed whether or not the rust preventive material has been washed away.
In other words, according to the present invention, it is possible to accurately and easily determine the head protection and maintenance mechanism (10) that requires injection of a rust preventive material.

Here, when the tension material (31) is unloaded during repair, the tension material (31) has been pulled into the ground, and so on. (30) If the vertical position of the head is on the basement side (deep side), even if a sight glass is formed on the side, the head of the ground anchor (30) from the sight of the side (1A) It is difficult to visually recognize the part.
However, according to the present invention, the head of the ground anchor (30) can be visually recognized from the top view window (2A: top view window). Even on the deep side, it can be easily and accurately determined whether water has entered the head protection and maintenance mechanism (10).

It is explanatory drawing which shows the ground anchor head to which embodiment of this invention is applied. It is a front sectional view of the head protection and maintenance mechanism concerning an embodiment of the present invention. It is a top view of the head protection and maintenance mechanism concerning an embodiment of the present invention. It is an AA arrow line view of FIG. It is a bottom view of the base in an embodiment. It is front sectional drawing for demonstrating the effect of this invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
The head of the ground anchor 30 to which the head protection and maintenance mechanism according to the illustrated embodiment is applied has a head protection and maintenance mechanism shown as a whole by 10 in FIG. As shown in FIG. 2, the head protection and maintenance management mechanism 10 includes a base 1 and a top 2.
In FIG. 1, the ground anchor 30 includes a plurality of strands 31 of PC steel that is a tensile material.
The PC steel stranded wire 31 is inserted into the ground through the center hole 32A of the pressure receiving plate 32 disposed on the ground G and the anchor hole (not shown) formed in the ground G, and is constructed by a grout material (not shown) filled in the ground. It is established on the ground.

In FIG. 1, the ground end of the PC steel stranded wire 31 protrudes upward from an anchor plate 33 disposed on the pressure receiving plate 32.
The PC steel stranded wire 31 is fixed to the anchor plate 33 by a tightening mechanism (not shown) in a state where a tensile force is applied by a tensile force applying device (for example, a jack) (not shown). As the tightening mechanism, for example, a fixing wedge or a fixing nut can be used.
In FIG. 1, the ground anchor head protection and maintenance management mechanism 10 is disposed so as to surround the head of the ground anchor 30 (portion protruding to the ground side). At that time, the head protection and maintenance management mechanism 10 is attached to the pressure receiving plate 32 by a fastening member 34. The base outer shell portion 11 of the head protection and maintenance mechanism 10 is formed with four attachment holes 11F as through-holes through which the fastening members 34 are inserted (FIGS. 2, 3, and 5). ).

As shown in FIG. 2, the head protection and maintenance mechanism 10 has a base 1 and a top 2. The base portion 1 has a hollow cylindrical base outer shell portion 11 and a transparent cylindrical member 12 formed of a transparent member (for example, acrylic).
In FIG. 2, a step portion 11B is formed in the base outer shell portion 11, and a transparent cylindrical member 12 is engaged with the step portion 11B and fixed in a known manner. As a result, the transparent cylindrical member 12 is engaged and fixed inward in the radial direction of the base outer shell portion 11.
An O-ring 14 is provided between the upper end surface of the transparent cylindrical member 12 and the step portion 11B of the base outer shell portion 11, and between the lower end surface of the transparent cylindrical member 12 and the upper surface of the pressure receiving plate 32 (FIG. 1). An O-ring 15 is provided.
The O-ring 14 seals the gap between the stepped portion 11B of the base outer shell portion 11 and the transparent cylindrical member 12, and maintains waterproofness (watertightness). At the same time, the gap between the pressure receiving plate 32 (FIG. 1) and the transparent cylindrical member 12 is sealed by the O-ring 15 to maintain waterproofness (watertightness) (see also FIG. 5). Thereby, the waterproofness (watertightness) of the base 1 (or head protection and maintenance mechanism 10) is maintained.

In FIG. 4, four openings 11 </ b> A are formed at equal intervals in the circumferential direction on the side surface of the base outer shell portion 11. The opening 11A of the base outer shell portion 11 and the transparent cylindrical member 12 constitute a side view window 1A (first view window). However, the side observation window 1A (first observation window), the opening 11A of the base outer shell portion 11 and the transparent cylindrical member 12 constituting the first observation window can be omitted.
In FIG. 2, an overhang portion 11 </ b> C is formed on the upper portion of the base outer shell portion 11, and the overhang portion 11 </ b> C supports the top 2 and the transparent disk-shaped member 22 on the top surface. An opening 11D constituting a top observation window 2A (second observation window: see FIG. 3) is formed in the central portion in the radial direction of the overhanging portion 11C.
A flange portion 11 </ b> E for attaching to the pressure receiving plate 32 (FIG. 1) is formed in the lower portion of the base outer shell portion 11. As described above, the attachment holes 11F are formed in the flange portion 11E, and the attachment holes 11F are formed as four through holes for inserting the fastening member 34 at equal intervals in the circumferential direction (FIGS. 2 and 2). 3, FIG. 5).

In FIG. 2, a top viewing window 2 </ b> A (second viewing window: see FIG. 3) is formed on the top 2. The top part 2 has a disk-shaped top outer shell part 21 and a transparent disk-shaped member 22 formed of a transparent member (for example, acrylic).
An opening 21 </ b> A is formed in the central portion in the radial direction of the top outer shell portion 21. Further, a step portion 21B is formed inward in the radial direction of the top outer shell portion 21, and a transparent disk-shaped member 22 is engaged with the step portion 21B. A transparent disk-shaped member 22 is engaged with the top outer shell portion 21 inward in the radial direction.

In FIG. 2, the top outer shell portion 21 is fixed to the base outer shell portion 11 by fastening members 23 (see FIG. 3) arranged at six locations at equal intervals in the vicinity of the outer peripheral portion. The transparent disk-shaped member 22 is fixed in a state where it is engaged with the stepped portion 21B of the top outer shell portion 21 and supported by the protruding portion 11C of the base outer shell portion 11. Six attachment holes for fastening members 23 are formed in the top outer shell portion 21 and the base outer shell portion 11 of the head protection and maintenance mechanism 10 (see FIG. 3).
Here, the opening 21A of the top outer shell portion 21 and the opening 11D of the protruding portion 11C of the base outer shell portion 11 are formed so as to have substantially the same inner diameter. Then, the top window 2A is configured by the transparent disk-shaped member 22, the opening 21A of the top outer shell portion 21, and the opening 11D of the overhang portion 11C.

An O-ring 16 is provided between the upper surface of the transparent disk-shaped member 22 and the stepped portion 21B of the top outer shell portion 21, and between the lower surface of the transparent disk-shaped member 22 and the upper surface of the protruding portion 11C of the base outer shell portion 11. Is provided with an O-ring 17.
The O-ring 16 seals the gap between the stepped portion 21B of the top outer shell portion 21 and the transparent disk-shaped member 22, and the O-ring 17 seals the protruding portion 11C of the base outer shell portion 11 and the transparent disk shape. The gap with the member 22 is sealed, so that the waterproofness (watertightness) of the top portion 2 and the base portion 1 is maintained.

As shown in FIGS. 3 and 4, the head protection and maintenance mechanism 10 has a rust preventive material (for example, grease) injection mechanism 13 (grease nipple) at an upper position on the side surface of the base 1.
When the head protection / maintenance management mechanism 10 is attached to the pressure receiving plate 32 and the head protection / maintenance management mechanism 10 for ground anchor is started to operate, the inside of the head protection / maintenance management mechanism 10 (the hollow of the base 1) Do not fill the interior) with a rust inhibitor (eg grease). However, since the head protection / maintenance management mechanism 10 has the grease nipple 13, a rust preventive material can be injected and filled into the head protection / maintenance management mechanism 10 as necessary.

As shown in FIG. 1, by covering the head of the ground anchor 30 with the head protection and maintenance mechanism 10, the head of the ground anchor 30 can be blocked from rainwater and the like, thereby preventing corrosion.
For example, by disposing a water stop member (not shown) (not shown) in the lower space (not shown) below the pressure receiving plate 32, groundwater can be prevented from entering the lower space. It is possible to prevent the stranded wire (tensile material) in the space from being corroded by contact with the groundwater.

As described above, when the head protection and maintenance mechanism 10 is started, the head protection and maintenance mechanism 10 (in the hollow portion of the base 1) is not filled with a rust preventive material (for example, grease). . Even if it is visually recognized from the top view window 2A (or the side view window 1A), it is not confirmed that water such as groundwater has entered the head protection and maintenance mechanism 10 (the head of the ground anchor 30). This is because it is not necessary to fill the head protection and maintenance management mechanism 10 with a rust preventive material. In other words, if water such as groundwater does not enter the head protection and maintenance mechanism 10, the ground anchor 30 head is not likely to corrode even if it is not filled with a rust preventive material (for example, grease). .
Since the head protection and maintenance mechanism 10 according to the illustrated embodiment is not filled with a rust preventive material at the start of operation, the rust preventive material is washed away from the head protection and maintenance mechanism 10. It does not pollute the surrounding environment.

  Groundwater or the like has entered the head protection and maintenance mechanism 10 of the head of the ground anchor 30 due to a change over time or other reasons, or through the surface of the sheath 31 or the PC steel strand 31 (tensile material). In such a case, the intrusion of water can be confirmed by visually recognizing from the top view window 2A (or the side view window 1A).

In addition, after injecting (filling) the rust preventive material into the head protection and maintenance management mechanism 10, the rust preventive material was washed away if viewed from the top view window 2 </ b> A (or the side view window 1 </ b> A) every predetermined period. It is possible to easily and accurately confirm whether or not the reduction has occurred. When the rust preventive material inside the head protection and maintenance management mechanism 10 is reduced, a rust preventive material (for example, grease) can be injected from the grease nipple 13 to be replenished and filled.
And without removing the head protection and maintenance mechanism 10, the state of filling of the rust preventive material inside the head protection and maintenance mechanism 10 can be visually recognized from the top observation window 2A (or the side observation window 1A). As in the prior art, it is not necessary to remove the head cap from the pressure receiving plate or the bearing plate for each of a large number of ground anchors, and the work of reattaching the removed head cap is unnecessary. Therefore, it is possible to easily and accurately determine the head protection and maintenance management mechanism 10 that requires injection of a rust preventive material (for example, grease), and easily replenish and fill the rust preventive material.

As shown in FIG. 6, for example, if the tensile material 31 (PC steel stranded wire) is unloaded at the time of repair, the tensile material 31 has been pulled into the ground, and therefore the head of the ground anchor 30 The vertical position may be on the underground side (deep side). Here, in the state shown in FIG. 6, since the tensile material 31 (PC steel strand) has been drawn into the ground, the PC steel strand 31 is fixed to the fixing tool 36 by the fixing wedge 35, and the fixing tool is used. A nut 37 is rotated with respect to 36 to apply a tensile force to the wire 31 from the PC steel.
When a tensile material (PC steel strand) has been drawn into the ground, it is difficult to visually recognize the ground anchor head from the side observation window 1A. However, in the illustrated embodiment, the head of the ground anchor 30 can be visually recognized from the top viewing window 2A, so that the head is protected and maintained even when the vertical position of the ground anchor head is on the underground side (deep side). It is possible to easily and accurately determine whether water has entered the management mechanism 10.

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.
For example, although the four side windows 1A are provided at equal intervals in the circumferential direction of the base 1 in the illustrated embodiment, three, two, or other numbers can be provided. Further, as described above, the side window 1A can be omitted. In that case, the opening 11A of the base outer shell 11 and the transparent cylindrical member 12 can be omitted.
Further, the material of the transparent cylindrical member 12 and the transparent disk member 22 is not limited to acrylic resin. Any material that is transparent and has a predetermined strength can be selected.

1 ... Base 1A ... Side view window (first view window)
DESCRIPTION OF SYMBOLS 11 ... Base outer shell part 12 ... Transparent cylindrical member 13 ... Grease nipple (injection mechanism)
2 ... Top 2A ... Top view window (second view window)
21 ... Top shell portion 22 ... Transparent disk-shaped member 10 ... Head protection and maintenance mechanism 30 ... Ground anchor 31 ... PC steel strand (tensile material)
32 ... Pressure plate

Claims (2)

A hollow-shaped base and a top surface or a peep window on either side are formed, and the top has a transparent member fitted radially inward,
A ground anchor head protection and maintenance mechanism characterized in that the hollow portion of the base is not filled with a rust preventive material.   The ground anchor head protection and maintenance mechanism according to claim 1, wherein a rust preventive material is filled in the hollow portion of the base after being attached to the ground anchor head.

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