JP4384941B2 - Ground anchor - Google Patents

Description

  The present invention relates to a ground anchor, and more particularly, to a ground anchor provided with an elastic member that absorbs fluctuations in tendon tension due to ground fluctuations.

  As an example of this type of ground anchor, as shown in FIG. 10, a tendon 52 having one end fixed to the ground 40 and the other end exposed from the ground surface is provided between the other end of the tendon 52 and the ground surface. The fixing device 57 that holds the tendon 52 in a tensioned state and the tension device 52 attached to the fixing device 57 to transmit the tension force of the tendon 52 to the ground surface, and absorb the fluctuation of the tension force of the tendon 52 due to the fluctuation of the ground 40. A ground anchor 50 having an elastic member 68 is proposed.

  In this case, the fixing device 57 includes a first fixing plate 58 fixed to the tendon 52 side and a second fixing plate 65 fixed to the ground surface side, and the first fixing plate 58 and the second fixing plate 65. Between the two, a single disc spring 69 as an elastic member 68 is interposed.

  As another example of the ground anchor, as shown in FIG. 11, two disc springs 69 and 69 are interposed in series between the first fixing plate 58 and the second fixing plate 65 of the fixing device 57. The ground anchor 50 which comprises the elastic member 68 is proposed.

In the ground anchor 50 configured as described above, the tension of the tendon 52 is transmitted to the ground surface via the first fixing plate 58, the disc spring, and the second fixing plate 65, so that the cut slope is obtained. Measures to prevent landslides such as Further, even if the ground changes due to frozen soil, melting, etc., the disc spring 69 expands and contracts following the change, so that the tension force of the tendon 52 can be applied to the ground side without being affected by the change in the ground. Therefore, it is possible to take measures to prevent landslides such as cut slopes in the long term (see, for example, Patent Document 1 and Patent Document 2).
JP2003-184080A JP2003-184081

  However, in the ground anchor 50 configured as described above, between the disc spring 69 and the first fixing plate 58, between the disc spring 69 and the second fixing plate 65, and the adjacent disc spring 69 and the disc. Since nothing is provided between the spring 69, when the disc spring 69 expands and contracts, the disc spring 69 is displaced in the horizontal direction and the circumferential direction, so that the end of the disc spring 59 is first fixed. The plate 58, the second fixing plate 65, or the end portion of the adjacent disc spring 69 slides, and wear occurs in that portion. When such wear occurs at the end of the disc spring 69, the antirust coating applied to the surface of the disc spring 69 is peeled off, causing rust. Since the ground anchor 50 is often used with a large tension applied to the tendon 52 and is often used outdoors, the environmental conditions against rust are extremely severe. Rust caused by the damage gradually spreads over the entire disc spring 69 and affects the strength of the disc spring 69. In addition, since the disc spring 69 is formed of high-quality spring steel, the function as the disc spring 69 is greatly reduced due to rusting.

  On the other hand, in order to prevent the disc spring 69 from rusting, as shown in FIG. 12, the other end of the tendon 52, the first fixing plate 58, the disc spring 69 are placed in the recess 56 of the pressure receiving plate 55 laid on the ground surface. And the ground anchor 50 configured to prevent the disc spring 69 from being rusted by accommodating the second fixing plate 65, filling the recess 56 with oil, and closing the opening with the lid 60. Proposed.

  However, in the ground anchor 50 configured as described above, since the volume of the concave portion 56 that accommodates the disc spring 69 is large, a large amount of oil is required, resulting in high costs. Further, since the disc spring 69 is located in a portion closed by the first fixing plate 58 and the second fixing plate 65, it is difficult to fill the portion with oil, and a sufficient amount is provided at the end of the disc spring 69. The oil cannot be supplied. For this reason, even when the oil is filled, it is necessary to apply a rust preventive measure by applying a coating to the surface of the disc spring 69, which increases the cost.

The present invention has been made in view of the above-described conventional problems, and it is possible to prevent wear at the end of a disc spring without using oil and without coating the surface of the disc spring. An object of the present invention is to provide a ground anchor that can be surely prevented, and that can provide stable performance in the long term without increasing the cost.

The present invention employs the following means in order to solve the above problems.
That is, the invention according to claim 1 is provided between a tendon having one end fixed to the ground and the other end exposed from the ground, and between the other end of the tendon and the ground, and tensioning the tendon. A grounding device provided with a fixing tool that is held in a fixed state, and a disc spring that is provided on the fixing tool and transmits the tension force of the tendon to the ground surface side and absorbs the variation of the tension force of the tendon due to the ground variation It is an anchor, The cover which covers this contact part is provided only in the contact part with the said fixing tool of the internal diameter part of the said disk spring, and an outer diameter part, It is characterized by the above-mentioned.
According to the ground anchor of the present invention, the contact portions of the inner diameter portion and the outer diameter portion of the disc spring with the fixing tool are covered with the cover, so that even if the disc spring is elastically deformed due to ground fluctuation, The inner diameter portion and the outer diameter portion of the spring are not directly brought into sliding contact with the fixing tool, and the inner diameter portion and the outer diameter portion of the disc spring are not worn.

The invention according to claim 2 is the ground anchor according to claim 1, wherein the fixing tool is a first fixing plate fixed to the other end of the tendon, and a second fixing plate fixed to the ground surface. And a disc spring is interposed between the first fixing plate and the second fixing plate, and the first fixing plate and the second fixing plate at the inner and outer diameter portions of the disc spring. A first cover and a second cover that cover the contact portion are provided only on the contact portion with the fixing plate, respectively .
According to the ground anchor of the present invention, the contact portions of the inner diameter portion and the outer diameter portion of the disc spring with the first fixing plate and the second fixing plate are covered with the first cover and the second cover. The inner and outer diameter portions of the disc spring are not directly in sliding contact with the first fixing plate and the second fixing plate. Even if the disc spring is elastically deformed due to ground fluctuation, There is no occurrence of wear on the part and the outer diameter part.

The invention according to claim 3 is the ground anchor according to claim 1 , wherein the fixing device includes a first fixing plate fixed to the other end of the tendon and a second fixing plate fixed to the ground surface. And a plurality of disc springs are interposed in series between the first fixing plate and the second fixing plate, and the first fixing tool at the inner and outer diameter portions of the upper and lower disc springs. The first cover and the second cover that cover the contact portion are provided only on the contact portion with the second fixing tool and only on the contact portion between the inner diameter portion and the outer diameter portion of the adjacent disc spring. It is characterized by.
According to the ground anchor of the present invention, the inner diameter portion and the outer diameter portion of the upper and lower ends of the disc spring are in contact with the first fixing plate and the second fixing plate, and the counterparts of the inner diameter portion and the outer diameter portion of the adjacent disc springs. Since the contact portion with the disc spring is covered with the first cover and the second cover, the inner and outer diameter portions of the upper and lower disc springs are in direct contact with the first fixing plate and the second fixing plate. The inner and outer diameter portions of the adjacent disc springs are not in direct contact with the mating disc spring. The inner and outer diameter portions of the upper and lower disc springs and the inner diameter of the adjacent disc spring There is no occurrence of wear on the part and the outer diameter part.

As described above, according to the ground anchor of the present invention, the contact portion of the inner diameter portion and the outer diameter portion of the disc spring with the fixing tool (first fixing plate and second fixing plate) is the cover (first cover and second fixing plate). Since the inner and outer diameter portions of the disc spring are not in direct contact with the fixing tool (the first fixing plate and the second fixing plate), the plate is changed due to ground fluctuation. Even if the spring is elastically deformed and displaced in the radial direction and the circumferential direction, the inner diameter portion and the outer diameter portion of the disc spring are not worn.
Further, even when a plurality of disc springs are interposed in series between the first fixing plate and the second fixing plate, the first fixing plate and the second fixing plate of the inner and outer diameter portions of the upper and lower disc springs are also provided. Since the contact portion with the fixing plate and the contact portions of the inner and outer diameter portions of the adjacent disc springs with the counterpart disc spring are covered with the first cover and the second cover, the inner diameters of the upper and lower disc springs The outer and outer diameter portions are not in direct contact with the first fixing plate and the second fixing plate, and the inner and outer diameter portions of the adjacent disc springs are not in direct contact with the mating disc spring. Wear does not occur in the inner and outer diameter portions of the disc springs at the upper and lower ends and the inner and outer diameter portions of the adjacent disc springs.
Accordingly, it is not necessary to immerse the disc spring, the fixing tool (first fixing plate and second fixing plate) in oil, and it is not necessary to apply the coating to the surface of the disc spring. Stable performance can be obtained.

Hereinafter, embodiments of the present invention shown in the drawings will be described.
1 to 6 show a first embodiment of a ground anchor according to the present invention. FIG. 1 is a longitudinal sectional view showing substantially the whole ground anchor, and FIG. 2 is a perspective view of a disc spring of FIG. 3 is a cross-sectional view taken along line AA in FIG. 2, FIG. 4 is a cross-sectional view of the second cover, FIG. 5 is an enlarged view of a portion B in FIG. 4, and FIG. 7 is a sectional view of the second cover, and FIG. 8 is an enlarged view of a portion C in FIG.

  That is, this ground anchor 1 is used for landslide countermeasures such as a cut slope, and as shown in FIG. 1, Tendon 2 and Tendon 2 placed on the ground 40 of the target location are connected. The fixing device 7 that holds the tensioned state and the elastic member 18 that transmits the tension of the tendon 2 to the ground 40 side and absorbs the variation of the tension of the tendon 2 due to the fluctuation of the ground 40 are provided.

  The tendon 2 is composed of a linear member 3 such as a plurality of PC steel stranded wires, and is inserted into the hole 41 of the ground 40 while being accommodated in the cylindrical sheath 4. Each linear member 3 of the tendon 2 has one end portion (lower end portion) fixed to the deep layer portion (not shown) of the ground 40 together with a sheath (not shown) together with the sheath 4, and the other end portion (upper end portion) is a pressure receiving plate. 5 and is exposed from the ground surface 43.

  A fixing tool 7 is provided between the other end portion exposed from the ground surface 43 of the tendon 2 and the ground surface 43. As shown in FIG. 1, the fixing tool 7 includes a first fixing plate 8 fixed to the other end of the tendon 2, a bearing plate 11 provided in close contact with the upper portion of the first fixing plate 8, and a bearing plate. 11 includes a chuck 13 for fixing the tendon 2 and a second fixing plate 15 fixed to an upper portion of the pressure receiving plate 5 laid on the ground surface 43.

  The second fixing plate 15 has a metal plate shape, and has a through hole 16 penetrating between the upper and lower surfaces in the center, and a cylindrical metal guide pipe 17 in the through hole 16. The guide pipe 17 and the second fixing plate 15 are integrally connected by welding or the like.

  The pressure receiving plate 5 is made of concrete or the like, and is provided with a support hole 6 penetrating between the upper and lower surfaces in the center, and by inserting a guide pipe 17 into the support hole 6 from above, 2 The fixing plate 15 is fixed to the upper part of the pressure receiving plate 5. The lower end portion of the guide pipe 17 is integrally connected to the upper end portion of the sheath 4 inserted into the support hole 6 of the pressure receiving plate 5 by welding or the like.

  The first fixing plate 8 has a metal plate shape and is provided with a through hole 9 penetrating between the upper and lower surfaces at the center. An upper end portion of a cylindrical slide pipe 10 is integrally connected to a peripheral portion of the through hole 9 on the lower surface side of the first fixing plate 8 by welding or the like. The slide pipe 10 is connected to the guide pipe 17 of the second fixing plate 15. It is slidably inserted into the inside from above.

  The support plate 11 has a plate shape and is provided in close contact with the upper portion of the first fixing plate 8 so as to close the through hole 9. A plurality of tendon support holes 12 penetrating between the upper and lower surfaces are provided at a plurality of locations of the pressure bearing plate 11, and each linear member 3 of the tendon 2 is inserted through each tendon support hole 12. The upper end opening of each tendon support hole 12 has an inner peripheral surface formed into a tapered surface having a predetermined angle, and a chuck 13 described later can be engaged with the upper end opening.

  The chuck 13 is configured by combining a plurality of wedge-shaped claws 14, and the outer surface of each claw 14 is formed into a tapered surface that matches the tapered surface of the upper end opening of the tendon support hole 12 of the bearing plate 11. The inner surface of each claw 14 is provided with recesses and protrusions for biting into the outer surface of the linear member 3 of the tendon 2.

  The linear members 3 of the tendons 2 are inserted into the tendon support holes 12 of the bearing plate 11 and the linear members 3 are tensioned by jacks (not shown), and the outer peripheral surfaces of the linear members 3 and the tendons. By driving the chuck 13 between the inner peripheral surface of the support hole 12, the other end of each linear member 3 is supported by the first fixing plate 8 via the chuck 13 and the support plate 11, and each linear member 3 is It is kept in tension.

  As shown in FIGS. 1 and 2, the elastic member 18 is a disc spring 19 and is formed in a truncated conical plate shape using spring steel or the like as a material. A through hole 20 penetrating between the upper and lower surfaces is provided in the central portion of the disc spring 19. By inserting the slide pipe 10 of the first fixing plate 8 into the through hole 20, the disc spring 19 is fixed to the first fixing plate 19. It is interposed between the plate 8 and the second fixing plate 15.

The disc spring 19 is interposed between the fixing plates 8 and 15 such that the top portion (inner diameter portion) is located on the first fixing plate 8 side and the bottom portion (outer diameter portion) is located on the second fixing plate 15 side. Has been. The disc spring 19 has an end surface 21 on the top side and an end surface 22 on the bottom side formed in a plane perpendicular to the inner peripheral surface 23 and the outer peripheral surface 24, and a corner portion 25 where the end surface 21 on the top side intersects with the outer peripheral surface 24. A corner portion 26 that contacts the lower surface side of the first fixing plate 8 and intersects the end surface 22 on the bottom side and the inner peripheral surface 23 is in contact with the upper surface side of the second fixing plate 15.
more than

  A first cover 27 and a second cover 34 are interposed between the top of the disc spring 19 and the first fixing plate 8 and between the bottom of the disc spring 19 and the second fixing plate 15, respectively. The first cover 27 and the second cover 34 provide a corner 25 on the top end of the top of the disc spring 19 (contact portion 25 with the first fixing plate 8) and a corner 26 on the lower end of the bottom of the disc spring 19 (second The contact portion 26) with the fixing plate 15 is covered.

  As shown in FIGS. 4 and 5, the first cover 27 has a substantially L-shaped cross section including a tapered tubular portion 28 and an annular flange portion 30 integrally provided at the upper end of the tubular portion 28. The boundary portion between the cylindrical portion 28 and the flange portion 30 is formed on a rounded surface 32 having a predetermined curvature. The first cover 27 is not limited to the shape described above, and may be any shape that has an influence on the characteristics (load-displacement curve) of the disc spring 19 of less than 5%.

  The first cover 27 is attached to the top of the disc spring 19 by fitting the cylindrical portion 28 into the through hole 20 of the disc spring 19. In this case, the outer peripheral surface 29 of the cylindrical portion 28 of the first cover 27 comes into contact with the upper end portion of the end surface 21 at the top of the disc spring 19, and that portion is covered, and the lower surface 31 of the flange portion 30 of the first cover 27. Comes into contact with the upper end portion of the outer peripheral surface 24 of the disc spring 19 to cover that portion.

  By attaching the first cover 27 to the top of the disc spring 19, the upper end of the first cover 27 contacts the lower surface side of the first fixing plate 8. In this case, as shown in FIG. 5, the contact portion of the first cover 27 with the first fixing plate 8 is formed on the rounded surface 32 having a predetermined curvature, and the first fixing is performed when the disc spring 19 is elastically deformed. The frictional resistance with the plate 8 is reduced. The contact portion of the first cover 27 with the first fixing plate 8 may be formed on a flat surface 33 substantially parallel to the lower surface of the first fixing plate 8 as shown in FIG.

  As shown in FIGS. 7 and 8, the second cover 34 has a substantially L-shaped cross section including an annular flange portion 35 and a tapered tubular portion 36 that is integrally provided at the outer peripheral end of the flange portion 35. The boundary portion between the flange portion 35 and the cylindrical portion 36 is formed on a rounded surface 37 having a predetermined curvature. The second cover 34 is not limited to the shape described above, and may be any shape that has an influence on the characteristics (load-displacement curve) of the disc spring 19 of less than 5%.

  The second cover 34 is attached to the bottom portion of the disc spring 19 by fitting the upper surface side of the flange portion 35 to the inner peripheral surface 23 side of the bottom portion of the disc spring 19. In this case, the upper surface of the flange portion 35 of the second cover 34 is covered by contacting the lower end portion of the inner peripheral surface 23 of the bottom portion of the disc spring 19, and the inner periphery of the cylindrical portion 36 of the second cover 34 is covered. When the surface comes into contact with the lower end portion of the end surface 22 at the bottom of the disc spring 19, the portion is covered.

  By attaching the second cover 34 to the bottom of the disc spring 19, the lower end of the second cover 34 contacts the upper surface side of the second fixing plate 15. In this case, the contact portion of the second cover 34 with the second fixing plate 15 is formed on the rounded surface 37 having a predetermined curvature as shown in FIG. 8, and the second fixing is performed when the disc spring 19 is elastically deformed. The frictional resistance with the plate 15 is reduced. Although not shown, the contact portion of the second cover 34 with the second fixing plate 15 may be formed on a plane substantially parallel to the lower surface of the second fixing plate 15.

  Examples of the material of the first cover 27 and the second cover 34 include stainless steel. However, the material is not limited to this, and any material having excellent corrosion resistance may be used. If necessary, the surfaces of the first cover 27 and the second cover 34 may be coated with a tetrafluoroethylene resin or the like to improve lubricity.

  In the ground anchor 1 according to this embodiment configured as described above, the tension force of the tendon 2 is transmitted to the ground 40 side through the fixing tool 7 and the disc spring 19 which is the elastic member 18, so that the ground Forty surface layer portions 42 are compressed between the deep layer portion and the pressure receiving plate 5, and landslides and the like are prevented from occurring in the surface layer portion 42.

  When the ground 40 changes such as frozen soil and thawed, the disc spring 19 expands and contracts in the axial direction of the tendon 2 following the change of the ground 40, so that the change is absorbed and the tendon 2 The tension force of the tendon 2 is prevented from fluctuating, and the tendon force of the tendon 2 is excessively prevented from being damaged.

  In this case, the disc spring 19 is displaced in the radial direction and the circumferential direction by expanding and contracting, but the corner portion 25 (contact portion with the first fixing plate 8) on the top side of the disc spring 19 is the first. Since the corner 26 on the bottom side of the disc spring 19 (the contact portion with the second fixing plate 15) is covered with the second cover 34, the corner 25 on the top side of the disc spring 19 is covered with the cover 27. Further, the corner portion 26 on the bottom side does not slide directly with the first fixing plate 8 and the second fixing plate 15.

  Therefore, the corner 25 on the top side of the disc spring 19 does not slide with the first fixing plate 8 and wear does not occur, and the corner 26 on the bottom side slides with the second fixing plate 15. Therefore, the disc spring 19 is not rusted due to wear, and the strength and function of the disc spring 19 can be prevented from being reduced due to rust. As a result, since the characteristics of the disc spring 19 can be sufficiently exhibited, a stable function as the ground anchor 1 can be exhibited for a long period of time.

  Further, since it is not necessary to apply a coating to the surface of the disc spring 19 or immerse the disc spring 19, the first fixing plate 8, the second fixing plate 15 and the like in oil, the cost can be greatly reduced. Become.

  FIG. 9 shows a second embodiment of the ground anchor according to the present invention. This ground anchor 1 is provided between the first fixing plate 8 and the second fixing plate 15 of the fixing tool 7. Two disc springs 19 and 19 are provided in series to constitute an elastic member 18, and a first cover 27 is interposed between the upper disc spring 19 and the first fixing plate 8, and the upper disc spring 19 and the lower side are arranged. Two disc covers 19 are interposed between the second disc spring 19 and a first cover 27 is interposed between the disc spring 19 on the lower side and the second fixing plate 15. Other configurations are the same as those shown in the first embodiment.

  In this case, the contact portion 25 of the upper disc spring 19 with the first fixing plate 8 is covered with the first cover 27, and the contact portion 25 of the lower disc spring 19 with the second fixing plate 15 is covered with the first cover 27. The contact portion 26 of the upper disc spring 19 with the lower disc spring 19 is covered with the second cover 34, and the lower disc spring 19 with the upper disc spring 19 of the contact portion 26 is second. Covered with a cover 34.

  And even in the ground anchor 1 shown in this embodiment, if the ground 40 changes due to frozen soil, thaw, etc., as in the first embodiment, the ground 40 changes. The two disc springs 19 and 19 are expanded and contracted in the axial direction of the tendon 2 to absorb the fluctuation and prevent the tendon 2 from changing in tension, and the tendon 2 has excessive tension. This prevents the tendon 2 from being damaged.

  In this case, the two disc springs 19 and 19 are displaced in the radial direction and the circumferential direction by expanding and contracting, but the top corners 25 (the first fixing plate 8 and the upper plate spring 19) are displaced. Of the lower disc spring 19 is covered with the first cover 27 and the upper corner spring 25 of the lower disc spring 19 is covered with the first cover 27. A corner 26 on the bottom side of 19 (contact portion with the lower disc spring 19) is covered with a second cover 34, and a corner 26 on the bottom side of the lower disc spring 19 (with the upper disc spring 19) is covered. Since the contact portion is covered with the second cover 34, the corner 25 on the top side of the upper disc spring 19 is the first fixing plate 8 and the corner 25 on the top side of the lower disc spring 19 is the first. 2 The fixing plate 15 and the corner 26 on the bottom side of the upper disc spring 19 are located on the bottom of the lower disc spring 19 and the bottom side of the lower disc spring 19. Part 26 does not like to bottom and direct sliding of the upper disc spring 19.

  Therefore, the corner portion 25 on the top side of the upper disc spring 19 does not slide and wear against the first fixing plate 8, and the corner portion 25 on the top portion of the lower disc spring 19 does not wear. There is no occurrence of wear due to sliding with the fixing plate 15, and no corner 26 on the bottom side of the upper disc spring 19 slides with the lower disc spring 19 to cause wear. Since the corner 26 on the bottom side of the lower disc spring 19 does not slide and wear with the upper disc spring 19, rust due to wear does not occur on each disc spring 19. It is possible to prevent a decrease in strength and function of each disc spring 19 due to rust. As a result, the characteristics of each disc spring 19 can be sufficiently exhibited, so that a stable function as the ground anchor 1 can be exhibited for a long time.

  Furthermore, it is not necessary to apply a coating to the surface of each disc spring 19 or immerse each disc spring 19, the first fixing plate 8, the second fixing plate 15 and the like in oil, so that the cost can be greatly reduced. It will be possible.

  In each of the above-described embodiments, an example in which one disc spring 19 and two disc springs 19 and 19 are used as the elastic member 18 has been described. However, although not illustrated, two or more disc springs are used. The elastic member may be configured, and in this case, the same function and effect can be obtained.

It is the longitudinal cross-sectional view which showed 1st Embodiment of the ground anchor by this invention. It is a perspective view of the disk spring of FIG. It is the sectional view on the AA line of FIG. FIG. 4 is a sectional view of the second cover. It is an enlarged view of the B section of FIG. It is the elements on larger scale which showed the modification of the 2nd cover. It is sectional drawing of a 2nd cover. It is an enlarged view of the C section of FIG. It is the longitudinal cross-sectional view which showed 2nd Embodiment of the ground anchor by this invention. It is the longitudinal cross-sectional view which showed an example of the conventional ground anchor. It is the longitudinal cross-sectional view which showed the other example of the conventional ground anchor. It is the longitudinal cross-sectional view which showed the other example of the conventional ground anchor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ground anchor 2 Tendon 5 Pressure receiving plate 7 Fixing tool 8 First fixing plate 11 Supporting plate 13 Chuck 15 Second fixing plate 18 Elastic member 19 Belleville spring 25 Corner portion 26 Corner portion 27 First cover 34 Second cover

Claims (3)

A tendon having one end fixed to the ground and the other end exposed from the ground; a fixing tool provided between the other end of the tendon and the ground; and holding the tendon in a tensioned state; and A ground anchor provided on a fixing tool and transmitting a tension force of the tendon to the ground surface side, and a disc spring that absorbs a variation of the tension force of the tendon due to a ground variation,
A ground anchor characterized in that a cover for covering the contact portion is provided only in the contact portion between the inner diameter portion and the outer diameter portion of the disc spring with the fixing tool . The fixing device includes a first fixing plate fixed to the other end of the tendon and a second fixing plate fixed to the ground surface, and the fixing device is interposed between the first fixing plate and the second fixing plate. Is provided with a first cover and a first cover covering only the contact portions of the inner and outer diameter portions of the disc spring with the first fixing plate and the second fixing plate. The ground anchor according to claim 1, wherein two covers are provided . The fixing device includes a first fixing plate fixed to the other end of the tendon and a second fixing plate fixed to the ground surface, and the fixing device is interposed between the first fixing plate and the second fixing plate. A plurality of disc springs are interposed in series, and only the inner diameter portion and the outer diameter portion of the upper and lower disc springs are in contact with the first fixing tool and the second fixing tool, and the inner diameter portions of the adjacent disc springs and 2. The ground anchor according to claim 1 , wherein a first cover and a second cover that cover the contact portion are provided only on a contact portion of the outer diameter portion with the counterpart disc spring, respectively .

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