JP2002267593A - Method for testing anchor body, method for adjusting, and supporting table and load cell used in these methods - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for safely, efficiently conducting work when a confirming test for fixing force and stretching force and adjustment of the stretching force is conduced at an execution job site to a lock bolt and various anchor bodies such as a ground anchor, and provide a supporting table and a load cell used there. SOLUTION: One end of an all screw lock bolt 3 is extruded outside and fixed to a hole H through a fixing filler G, and by fastening a nut screwing the bolt, stretching force is introduced. A joining bolt 32 is connected to the end of the all screw lock bolt 3, a lockwasher 2, a supporting table 1, and the load cell 41 are fit in order to the end part of the all screw lock bolt 3, and a loading nut 5 is screwed. For adjusting the stretching force, the loading nut 5 is fastened with a spanner 6, the load cell 41 is pressed with designed stretching force, and in this state, the lower spanner 9 mounted on the fastening nut is rotated in the optional direction to a contact state in which a practical load is not applied to the fastening nut, and the loading nut 5 is loosened until a load applied to the load cell 41 is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various types of rock bolts or ground anchors (hereinafter, collectively referred to as "anchor bodies") used for stabilizing slopes and tunnels and protecting rock fall. The present invention relates to a method for testing a fixing force and a tension, a method for adjusting a tension, and a support table and a load cell used in the methods.

[0002]

2. Description of the Related Art Anchor bodies such as rock bolts and ground anchors are widely used for stabilizing the ground and rocks on slopes associated with ground works, various types of civil engineering work, and tunnels. These anchor bodies are inserted in advance into holes drilled in the ground or rock by appropriate means such as a drilling machine or the like, and a fixing filler (grout material) such as mortar, synthetic resin or the like is injected into the voids. By the solidification, integration with the surrounding ground is achieved, and required tension is introduced by appropriate means. The construction of these anchors is designed on the assumption that a required fixing force is exhibited when the fixing filler is filled in the holes in a dense state without any gaps. For this reason, as a means for checking the construction management, after the filling operation is completed, when the fixing filler material reaches a predetermined strength, a pull-out test is performed on a number of anchor bodies at a fixed rate. In this way, the anchoring power of the anchor body is evaluated.

Conventionally, a test for confirming the anchoring force of an anchor body has been conducted by examining an exposed head of the anchor body or an extension member thereof (hereinafter referred to as an "exposed portion of the anchor body" including a connected extension member in this specification). ), And a substantially cylindrical jack support (ram chair) for setting the jack in place, using a load cell. A method of applying a predetermined load (pulling force) to the anchor body from the outside by combining load measuring devices such as the above is adopted (see the Japan Geotechnical Society, “Ground anchor design and construction standards”). Further, the tension of the anchor body is confirmed not only at the time of new installation but also at the time of re-tensioning of the existing anchor body. In any case, it is general to use the jack or the like. In the case where a screw portion can be formed on the outer peripheral surface of the end portion such as a PC steel rod as an anchor body, a tension is introduced by tightening a tightening nut screwed on the screw portion with a large torque wrench. Things have also been done.

[0004]

By the way, this kind of anchor body is often applied to a place with poor scaffolding such as a slope, but it is necessary to check the anchoring force and adjust the tension in order to fix the anchor body. On the other hand, it is indispensable to install hydraulic jacks so that their axes coincide with each other for accurate evaluation. Therefore, when performing work in such a place, it is necessary to preliminarily shape the ground surface on which the support base or the like is to be installed with a mortar or the like. Moreover,
Since the hydraulic jack and the like are heavy and bulky, there is a problem in terms of transportation to the test site and installation space, and there is a problem that workability is extremely poor. Furthermore, there is also a problem that handling a heavy object on the inclined surface has a high risk to an operator. On the other hand, when the tension is introduced by the torque wrench, the tool itself is small in weight, but the wrench with a long handle is operated. Therefore, it is inevitable that the operation involves danger. In addition, in this type of article, it is customary that the tightening nut and the thread portion of the anchor body are not subjected to a treatment for reducing friction for reasons such as manufacturing cost. For this reason, a large variation occurs in the coefficient of friction in the threaded portion between the two, and there is a possibility that the design tension is not introduced in the torque management.
There were some issues to improve.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and is intended to evaluate the anchoring force or tension of various types of anchors at a construction site and to adjust the tension in the construction site. It is an object of the present invention to provide a method capable of performing work efficiently with little danger, and a support table and a load cell suitable for the method.

[0006]

In order to solve these problems in the prior art, according to the first aspect of the present invention, one end is fixed in a perforation of the ground through a fixing filler with the one end exposed to the outside. In order to confirm the anchoring force of the anchor body, the anchoring body is inserted and inserted into the exposed part of the anchor body or its extension using an array of receiving washers, a substantially cylindrical support, an annular load cell, and a loading nut from the ground side. When the load cell is clamped with a predetermined load by tightening the loading nut, the fixing force is evaluated using an index in which the anchor body is not displaced in the pull-out direction as an index.

In the above construction, for example, a male screw is formed on the outer peripheral surface of the end on the exposed portion side of the anchor, or an appropriate extension member having the male screw is connected to the end of the anchor. When the loading nut is screwed into the male screw portion and tightened, a load in the pullout direction is applied to the anchor body fixed at the embedded portion on the other end side, and at the same time, the support base is placed on the exposed portion of the anchor body. The ring-shaped load cell inserted through the pinch is pinched between the ground and the load, and the load is displayed on appropriate display means connected to the load cell. Therefore, tighten the loading nut until the load becomes equivalent to the designed fixing force, and visually confirm that the anchor body does not displace in the pull-out direction under this condition, or preferably, use the displacement meter together with an appropriate If it can be confirmed that the anchor body is not displaced by a length equal to or greater than the extension of the anchor body, it can be determined that the design fixing force is satisfied. That is, by adopting these displacement states as indices for the confirmation test, it is possible to evaluate the anchoring force of the anchor body. This eliminates the need for a conventional heavy center-hole type hydraulic jack or the like, and enables simple and safe work even in a site with poor working conditions such as a steep slope.

In the invention according to the second aspect, the tightening nut is fixed in the perforation of the ground via the fixing filler while one end side is exposed to the outside, and screwed into the male screw portion provided in the exposed portion. When checking the tension of the anchor body to which the tension is introduced, the receiving washer, the substantially cylindrical support base, the annular load cell, and the When the load cell is clamped with a predetermined load by tightening the loading nut by inserting and inserting the nuts, it is necessary to evaluate the tension using the contact state where the tightening nut is substantially free of a load as an index. Features.

According to this structure, a load corresponding to the tension of the introduced anchor body is applied to the tightening nut which is pressed against the supporting plate or the like placed on the ground surface. , The load is due to the tightening of the loading nut,
The load moves sequentially from the tightening nut to the loading nut, and the load applied to the loading nut is displayed via the load cell. Then, when the load applied to the loading nut becomes a load corresponding to the design tension, it is possible to know whether the tension is excessive or insufficient by checking the screwing state of the tightening nut. That is, in the case where the tightening nut is still strongly tightened despite the load corresponding to the design tension being applied to the loading nut, the introduced tension is larger than the design value. is there. Further, when the tightening nut is separated from the supporting plate or the like that has been pressed and is loose, the tightening force is less than the designed value. Therefore, if the threaded state of the tightening nut when the load corresponding to the design tension is applied to the loading nut is used as an index, and it is confirmed which of the above states the tension is, the tension of the anchor body with respect to the design value is determined. Excess or deficiency can be easily evaluated.

Further, according to a third aspect of the present invention, there is provided a tightening nut which is fixed in a perforation of the ground via a fixing filler with one end exposed to the outside, and screwed into a male screw portion provided in the exposed portion. In adjusting the tension of the anchor body to which the tension is introduced, the receiving washer, the substantially cylindrical support base, the annular load cell, and the load for the exposed portion of the anchor body or its extension member from the ground side. After inserting the nuts in an array and holding the load cell with a predetermined load by tightening the loading nut, the tightening nut is rotated in an appropriate direction to make a contact state in which substantially no load is applied,
By loosening the loading nut until the load applied to the load cell disappears, the tension applied to the loading nut is moved to the tightening nut to obtain the set tension.

In this configuration, after confirming whether the introduction tension relative to the design tension of the anchor body is excessive or insufficient, the tension is continuously adjusted according to the result. That is, in the method of claim 2, under the condition that a load corresponding to the design tension is applied to the loading nut,
If the tightening nut is still tightly tightened, the introduced tightening force will be larger than the designed value, so that the tightening nut will be brought into a contact state in which a load is not substantially applied to the tightening nut using an appropriate tool. Loosen up. On the other hand, when the tightening nut that is in pressure contact with the supporting plate installed on the ground surface is separated from them and no load is applied to the tightening nut, the tension of the anchor body is insufficient. Therefore, the tightening nut is rotated in the tightening direction, and is brought into contact with the tightening nut to the extent that no load is applied in the same manner as described above. In such a state, all loads corresponding to the design tension are applied to the loading nut. Next, when the loading nut is loosened until the load on the load cell disappears, all the load applied to the loading nut moves to the tightening nut, and the tension of the anchor body can be adjusted to the set value.

According to a fourth aspect of the present invention, there is provided a support used in the first to third aspects of the present invention, wherein a portion of the support base facing the insertion hole of the receiving washer is formed in a spherical shape. By fitting into the insertion hole of the receiving washer at an appropriate position, a required inclined arrangement with respect to the insertion hole of the receiving washer is possible. That is, the axis of the substantially cylindrical support base can be brought into contact with the axis of the insertion hole of the receiving washer in an appropriate inclined state. For this reason, even when the axis of the anchor body is fixed in an inclined state with respect to the ground surface, the support base is supported by abutting against the receiving washer at an appropriate position within the range of the spherical surface. The axis of the through hole at the center of the load cell placed on the table can be aligned with the axis of the anchor body. As a result, the load from the loading nut screwed onto the exposed portion of the anchor body is surely applied to the load cell without bias, and greatly contributes to accurate evaluation of the fixing force and the tension. In addition, the spherical surface of the support base may be either convex or concave, and the corresponding washer does not necessarily need to be a spherical surface, and may have a shape that is in line contact with the spherical surface of the support base. It is more convenient to form spherical surfaces that can be fitted to each other.

According to a fifth aspect of the present invention, there is provided a load cell used in the method according to any one of the first to third aspects, wherein a thrust bearing is provided on a surface facing the loading nut. When this load cell is used, the load cell can be operated with a smaller force when tightening the loading nut, so that it is particularly advantageous for use in a place with a poor scaffold.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, when various types of anchors are evaluated for anchoring force or tension at a construction site and adjustment of tension is performed, use of a simple device such as a support base or a load cell is required. As a result, a method capable of performing work safely and efficiently has been realized. In addition, as the anchor body, for example, a rope screw or the like is formed over the entire length of the outer peripheral surface thereof like a full screw lock bolt, and when using a full screw bolt that can be easily lengthened through a coupler, the tip side thereof is used. The screw bolts having higher thread accuracy than the whole screw bolts, or a screw bolt whose friction coefficient is reduced by plating or the like are connected by appropriate means as an extension member, and a loading nut is screwed onto the connected screw bolts. Since a necessary load can be applied to the anchor body even with such a small rotational force, the danger of the worker is reduced, and the work efficiency is improved. It is preferable that the female screw portion of the loading nut be made the same. In the present invention,
Friction reduction when tightening the loading nut is an effective means in terms of improving workability, etc.
It is preferable to use a load cell provided with a thrust bearing on the surface where the loading nut is pressed. If a Bourdon tube type load cell is adopted as the load cell, no power source is required and the device itself is simple, so that it is easy to handle, especially on construction sites with poor scaffolding where many anchors of this type are applied. This is convenient from the point of view. In addition, particularly in the fixing force confirmation test, for example, when a displacement meter is installed at the end of the anchor body, whether the detected displacement is caused by extension at the anchor body exposed portion, or insufficient fixing force It is needless to say that the present invention is effective in judging whether or not the above is the case, and that various other generally employed technical means can be applied to the present invention.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are a partial longitudinal front view and a side view of a support base according to the present invention. Support 1 shown
Are provided with substantially rectangular openings 11 at two opposing positions on the peripheral surface of the cylindrical body, and annular portions 12 and 13 on both ends.
It has a shape in which a handle 15 is attached to one of two support legs 14 straddling between them. Further, an annular step portion 16 is provided on the inner peripheral surface of the upper annular portion 12 on the load cell side, and the outer peripheral surface of the other annular portion 13 on the receiving washer side described below is reduced in diameter toward the distal end side. It is formed as a convex spherical surface 17.

FIGS. 3 and 4 are a front view and a plan view, respectively, showing a portion of a receiving washer used together with the support table 1. FIG.
In the illustrated receiving washer 2, the inner peripheral edge at one end side of the annular main body 21 forms a concave spherical surface 22, and a handle 23 is further attached to the outer peripheral surface. In addition, this concave spherical surface 22
It is formed so as to fit with the convex spherical surface 17 of the annular portion 13 of the support base 1. The handle 23 can be used for carrying, like the handle 15 of the support base 1.

Next, a description will be given of a fixing force test of the anchor body using the support table 1 and the receiving washer 2 with reference to FIGS. The anchor body 3 targeted in this embodiment is:
As shown in FIG. 5 and the like, this is a self-drilling type all-screw lock bolt having a hollow shape in which a rope screw is formed by forging or the like over the entire length of the outer peripheral surface, and furthermore, a drill bit (not shown) is provided on the distal end side. The anchor body 3 is formed by drilling a hole H in the ground E.
It is fixed by a fixing filler G such as mortar or the like, which is filled around it while being inserted therein. This fixing filler G
Is injected from the base end side of the anchor body 3 by appropriate means, flows out from the drill bit H at the distal end through the hollow portion thereof, and solidifies in a state where the gap between them is filled. As a result, the anchor body 3 has a fixing force. When the solid anchor body 3 is used, an appropriate injection pipe may be inserted into the hole H to inject the fixing filler G.

In order to test the anchoring force of the anchor body 3 fixed in this way, first, as shown in FIG. 5, the exposed end of the anchor body 3 is connected via a coupler 31 as an extension member. The bolt 32 is connected, and the appropriate support plate 33 and the receiving washer 2 are inserted into the anchor body 3. At this time, the receiving washer 2 is installed so that the concave spherical surface 22 faces the coupler 31 side. The connecting bolt 32 used here is formed by cutting, for example, a metric fine thread, and has a smaller pitch than the rope screw of the anchor body 3 and a higher precision of the screw thread. Also the coefficient of friction is low. Also,
On the other end side of the connecting bolt 32, a small-diameter screw portion 32a for attaching a displacement measurement plate described later is formed.

Next, as shown in FIG. 6, the support 1 is placed on the concave spherical surface 22 of the receiving washer 2 such that the convex spherical surfaces 17 are fitted to each other. Subsequently, as shown in FIG. 7, an annular load cell 41, which is a main component of the load meter 4 described later, is inserted from the distal end side into the connecting bolt 32 projecting from the annular portion 12 of the support base 1. I do. At this time, by appropriately adjusting the fitting position of the support base 1 and the receiving washer 2 within the range of the spherical surface of each other, the load cell 4
The through hole in the center of 1 is parallel to the axis of the connecting bolt 32,
That is, the angle is adjusted so that the pressure receiving surface of the load cell 41 is orthogonal to the axis of the connecting bolt 32, and the loading nut 5
To the connection bolt 32.

As shown in FIG. 8, the load cell 4 used here has a bourdon tube 42 connected and integrated via an oil feed tube 43 to an annular load cell 41 in which oil is sealed. Further, a metal frame 44 for preventing damage and transport is provided around them, so that the load cell 41 is fitted to the annular step 16 of the support base 1. Also, on the surface where the loading nut 5 contacts,
A thrust bearing 45 is provided so that it can be operated with a smaller force when tightening the loading nut 5. Bourdon tube 42 as load indicating means
Is particularly suitable for use in places with poor scaffolding because it is inexpensive, does not require a power source, and can withstand rough handling. However, the load cell 4 including the pressure detecting means of the load cell 41 itself is not used. Of course, it is possible to change to the one of the form.

Further, as shown in FIG. 9, after the ratchet spanner 6 is mounted on the loading nut 5, the connecting bolt 32
The plate 7 for displacement measurement is fixed to the end of the
When the detection unit of the displacement meter 8 installed in an immobile state is appropriately brought into contact with the detection unit, the preparation for the anchoring force confirmation test of the anchor body according to the present invention is completed. In such a state, when the ratchet spanner 6 is rotated in the tightening direction while carefully checking the change of the displacement meter 8, a pulling force is applied to the anchor body 3 and the load cell 41 is simultaneously loaded with the loading nut 5 and the support base. 1 will be clamped. When the Bourdon tube 42 of the load meter 4 is tightened until a predetermined load (design fixing force) is displayed, a large change is made to the displacement meter 8 at this time, that is, when the predetermined load is applied, the connecting bolt 32 and the anchor If there is no displacement larger than the length at which the exposed portion of the body 3 extends, it can be evaluated that there is no problem in the fixing force. In the present invention, the displacement meter 8 is not essential, and may be visually checked. That is, it is out of the question that the anchor body 3 comes out of the hole H. However, an appropriate position above the loading nut 5 in the connection bolt 32 is used as a reference point, and the position is assumed to be equal to or greater than the extension of the connection bolt 32 or the like. If it is not moved upward by the distance of, the evaluation can be performed in the same manner.

Next, a description will be given of a tension confirmation test for the anchor body 3 and a method of adjusting the tension with reference to FIGS. Note that portions common to the above-described fixing force confirmation test method are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 10, a required tension is applied to the anchor body 3 fixed to the ground E by tightening the tightening nut 35 with the fixing washer 34 inserted through the exposed portion. The tightening nut 35 used here has a convex spherical surface 35a at the end in the tightening direction. Further, the inner peripheral edge portion of the fixing washer 34 opposed thereto is formed in a concave spherical surface, and both can be fitted to each other at an arbitrary position on the spherical surface portion. A male thread for attaching a rust prevention cap is formed on the outer peripheral surface of the fixing washer 34. The receiving washer 2 shown in FIGS. 3 and 4 is inserted outside the fixing washer 34 into the exposed portion of the anchor body 3 to which the tension is introduced in such a state, and the distal end side of the anchor body 3 is inserted. Represents coupler 3 in the same manner as in the above fixing method.
The connecting bolt 32 is connected via the first connecting bolt 32.

Subsequently, as shown in FIG.
The support base 1 is placed so that the spherical surfaces of the support table 1 fit each other, and the ratchet spanner 9 is mounted on the tightening nut 35. Further, as shown in FIG. 12, the load cell 41 of the load meter 4 is inserted into the connection bolt 32 protruding from the annular portion 12 of the support base 1 and the loading nut 5 is connected to the connection bolt 3.
Screw on 2. At this time, performing the angle adjustment by appropriately adjusting the fitting position between the support base 1 and the receiving washer 2 is as follows.
This is the same as the fixing force test. Then, as shown in FIG. 13, the other ratchet spanner 6 is attached to the loading nut 5.
When the displacement gauge 8 and the like are attached to the end of the connecting bolt 32, the test for confirming the tension of the anchor body according to the present invention is completed.

In such an installed state, the upper ratchet spanner 6 is tightened while checking the change of the displacement meter 8 until the Bourdon tube 42 of the load meter 4 indicates a predetermined load (design tension). With the tightening of the loading nut 5, a load corresponding to the tension applied to the tightening nut 35 pressed against the supporting plate 33 provided on the ground surface via the fixing washer 34 is transferred from the tightening nut 35 to the loading nut. We move sequentially to 5. When the Bourdon tube 42 of the load meter 4 indicates a predetermined load (design tension), the screwed state of the tightening nut 35 is confirmed. That is,
If the tightening nut 35 is in a contact state where a load is not substantially applied to the fixing washer 34, the tightening nut 35
This means that all the load (tensile force) applied to the nut has been transferred to the loading nut 5 as it is. Therefore, when the lower ratchet spanner 9 is to be rotated in the loosening direction, if the tightening nut 35 is still tightened, all the load applied to the tightening nut 35 does not move, and the load still remains. From the remaining, it can be determined that the tension introduced into the anchor body 3 is larger than the design load. When the tightening nut 35 is loose, the load (design tension) applied to the loading nut 5 is larger than the load originally applied to the tightening nut 35 (introduced tension). It can be seen that the body 3 lacks tension. In the present invention, by checking this condition as an index, it is possible to easily evaluate whether the tension in the anchor body 3 is as designed. When only checking the tension is performed, the lower ratchet spanner 9 is unnecessary, and the operator may manually check the threaded state of the tightening nut 35.

In the above confirmation test, when the designed tension is not introduced into the anchor body 3, a method of adjusting the tension will be described with reference to FIG. After confirming whether the tension of the anchor body 3 is excessive or insufficient by the above-described method, if a load still remains on the tightening nut 35, the lower ratchet spanner 9 is used so that the load is not substantially applied. The tightening nut 35 is loosened so as to abut the fixing washer 34. Conversely, when the tightening nut is separated from the fixing washer 34 and the tightening nut 35 is loose, the tightening nut 35 is rotated in the tightening direction, and a load is applied to the tightening nut 35 as described above. The fixing washer 34 is brought into contact with the fixing washer 34 to such an extent that the fixing is not performed. In such a state, the load corresponding to the design tension is all applied to the loading nut 5. Next, when the loading nut 5 is loosened until the load of the load cell 41 disappears, the entire load applied to the loading nut 5 is transferred to the tightening nut 35, and the anchor body 3 is released.
Can be adjusted to the design value.

In each of the above-described methods according to the present invention, the use of the support 1 having the spherical convex surface 17 allows the anchor body 3 to be fixed in an inclined state with respect to the surface of the ground E. The axis of the anchor 3 and the support 1 can be set in parallel. Thereby, the loading nut 5
Is securely transmitted to the load cell 41 of the load cell 4 and the load is measured on the entire surface of the pressure receiving portion.
It is hard to be in a one-sided state due to an unbalanced load, and accurate measurement of the load is possible. Further, since the Bourdon tube 42 is used as the load display means, the measurement can be easily performed at any place, and the measurement work can be performed safely and efficiently because of its light weight and small size.

In each of the above embodiments, an example in which the anchor body is applied to a hollow full-screw lock bolt has been described. However, there is no problem in applying the present invention to a lock bolt having a different peripheral surface shape or a solid shape. Further, instead of the lock bolt, a ground anchor using a plurality of stranded PC steel as a tensile material is used, for example, using an anchor head having an external thread portion formed on the outer peripheral surface, and a female screw portion that can be screwed into this. By connecting an appropriate extension member having a male screw portion on the other end side, a confirmation test and adjustment of tension can be performed in the same manner as in the above embodiment. The connecting bolt, which is an extension member, may be appropriately used in accordance with the length of the protrusion of the anchor body, and the shapes of washers and nuts can be changed. Further, various modifications within the technical concept of the present invention are possible, for example, by combining the load cell of the load cell with the support base or by using another type of load cell in consideration of transportation or the like.

[0028]

As described above, according to the first aspect of the present invention, the loading nut is tightened until a load corresponding to the designed fixing force is reached, and the anchor body is not displaced in the pull-out direction under this condition. If this can be visually confirmed, preferably by using a displacement meter, it can be determined that the fixing force is satisfied. That is, since the fixing force can be evaluated only by checking the above state as an index, a heavy center hole type hydraulic jack as in the related art becomes unnecessary, and it is simple and easy even in a site with poor working conditions such as a steep slope. You can work safely. In the fixing force confirmation test, when the support according to claim 4 of the present application is used, the load cell is installed in an appropriate penetrating state with respect to the anchor body or the like by an angle adjusting function between the receiving base and the washer. Therefore, there is an advantage that an unbalanced load hardly occurs on the pressure receiving surface of the load cell when the loading nut is tightened, which greatly contributes to accurate load application, and can be used for checking the tension and adjusting the tension as it is. Further, the use of the load cell according to the fifth aspect is an effective means for improving the safety of an operator and the like because the tightening of the loading nut becomes easy.

In the invention according to claim 2 of the present application, when the loading nut is tightened until a load corresponding to the designed tension is applied, the tightening nut is brought into contact with substantially no load. The tension is evaluated using the condition as an index.If the tightening nut is tightly tightened, the tension is larger than the design load.If the tightening nut is loose, the tension is insufficient. Therefore, the evaluation can be performed easily and safely without using a heavy jack as in the related art. When the support according to claim 4 of the present application is used, the fact that the angle adjustment function can be used for accurate load application is the same as the fixing force confirmation test, and the load cell according to claim 5 of the present application is used. Similar effects can be obtained when used.

Further, in the invention according to claim 3 of the present application,
If the tension is excessive or insufficient in the above confirmation test, and the load still remains on the tightening nut, loosen the tightening nut using a suitable tool until the contact state is such that the load is not substantially applied. Conversely, if no load is applied to the tightening nut, the tightening nut is rotated in the tightening direction and, as described above, is brought into contact with the load so that no load is applied, and until the load on the load cell disappears. By loosening the loading nut, the tension can be easily and accurately adjusted to the design value. Also in this case, the use of the support according to claim 4 of the present application is useful in adjusting the tension to an accurate value, and the use of the load cell according to claim 5 is based on the rotation of the loading nut. The practical effect is extremely large, such as facilitating operation and improving safety.

[Brief description of the drawings]

FIG. 1 is a partial vertical sectional front view showing an example of a support base according to the present invention.

FIG. 2 is a side view of the support table shown in FIG.

FIG. 3 is a vertical sectional front view of a receiving washer used with the support according to the present invention.

FIG. 4 is a side view of the receiving washer shown in FIG.

FIG. 5 is an explanatory view showing a state in which a receiving washer is installed in a fixing force test of the anchor body according to the present invention.

FIG. 6 is an explanatory view showing a state where a support base is installed in a fixing force test of an anchor body according to the present invention.

FIG. 7 is an explanatory view showing a state in which a load meter is installed in a fixing force test of the anchor body according to the present invention.

FIG. 8 is a plan view showing an example of a load cell used in the present invention.

FIG. 9 is an explanatory view showing a state in which test preparation is completed in the anchoring force test of the anchor body according to the present invention.

FIG. 10 is an explanatory view showing a state in which a receiving washer is installed in a tension test of an anchor body according to the present invention.

FIG. 11 is an explanatory view showing a state where a support base and the like are installed in a tension test of the anchor body according to the present invention.

FIG. 12 is an explanatory view showing a state in which a load meter is installed in a tension test of an anchor body according to the present invention.

FIG. 13 is an explanatory view showing a state in which preparation is completed in a tension test of an anchor body or adjustment thereof according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Support stand, 2 ... Receiving washer, 3 ... Anchor body, 4 ... Load cell, 5 ... Loading nut, 6, 9 ... Ratchet spanner, 8
... displacement gauge, 11 ... opening, 14 ... support leg, 17 ... spherical convex surface, 22 ... spherical concave surface, 31 ... coupler, 32 ... connecting bolt, 33 ... support plate, 34 ... fixation washer, 35 ... tightening nut, 41 ... load cell , 42 ... Bourdon tube, E: ground,
G: fixing filler, H: drilling

Claims (5)

[Claims] In order to check the anchoring force of an anchor fixed in a perforation of a ground through a fixing filler with one end exposed to the outside, an exposed portion of an anchor or an extension member thereof is checked. Then, from the ground side, the receiving washer, a substantially cylindrical support base, an annular load cell and a load nut are inserted in an array, and when the load cell is clamped with a predetermined load by tightening the load nut, the anchor body comes off. A test method for an anchor body that evaluates anchoring force using a state in which it does not displace in the direction as an index. 2. A fixing nut is fixed in a perforation of the ground through a fixing filler in a state where one end side is exposed to the outside, and a tension is introduced by a tightening nut screwed into a male screw portion provided in the exposed portion. In checking the tension of the anchor, the receiving washer, the substantially cylindrical support base, the annular load cell, and the loading nut were inserted into the exposed portion of the anchor or its extension member from the ground side. A test method for an anchor body, wherein when a load cell is clamped at a predetermined load by tightening a loading nut, a tension is evaluated by using an abutting state in which a load is not substantially applied to the tightening nut as an index. 3. A fixing nut is fixed in a perforation of the ground through a fixing filler with one end exposed to the outside, and a tension is introduced by a tightening nut screwed into a male screw portion provided in the exposed portion. In adjusting the tension of the anchor body, the exposed portion of the anchor body or its extension member is inserted and inserted from the ground side with an array of receiving washers, a substantially cylindrical support base, an annular load cell, and a loading nut. With the load cell clamped at a predetermined load by tightening the loading nut, the tightening nut is rotated in an appropriate direction to make a contact state in which substantially no load is applied, and then the load applied to the load cell disappears. A method of adjusting the anchor body in which the tension applied to the loading nut is moved to the tightening nut by loosening the loading nut until the tension is set. 4. A portion facing the insertion hole of the receiving washer is formed in a spherical shape, and is fitted into the insertion hole of the receiving washer at an appropriate position on the spherical surface, so that a required hole for the insertion hole of the receiving washer is provided. 4. A support for use in the method according to claim 1, wherein the support can be arranged in an inclined manner. 5. The load cell according to claim 1, wherein a thrust bearing is provided on a surface facing the loading nut.