JP6914022B2 - Unloading device and unloading method - Google Patents

Description

The present invention relates to a unloading device and a unloading method for a long construction member whose construction position is prestressed by tension.

A ground anchor is used as a long construction member for suppressing displacement by applying prestress in advance in measures for stabilizing road slopes and measures for preventing lifts or falls of building structures. The external force used to calculate the anchor force required for this ground anchor is stably calculated based on assumptions about soil constants, structure behavior, and the like. Therefore, when there is a difference between the assumption and the actual event, the tensile force acting on the ground anchor (residual tensile force) exceeds the allowable tensile force (allowable load) of the ground anchor due to an unexpected external force. There is. For the ground anchor that exceeds the allowable load, it is necessary to unload the ground anchor so that the ground anchor functions in a sound state so that the load is less than the allowable load.

Here, the head fixing method of the ground anchor is roughly classified into three types, a "wedge fixing method", a "nut fixing method", and a "wedge fixing / nut adjustment method". Of these, the ground anchor of the "wedge fixing method" is unloaded by using, for example, the unloading device and the unloading method described in Patent Documents 1 and 2. On the other hand, FIG. 23 shows the vicinity of the head of the ground anchor 80A of the “nut fixing method”, and the ground anchor 80A is placed on the surface of the ground G via the bearing plate 86 and the pressure receiving plate 88. The screw structure portion 82 provided at the end portion of the 80A is tension- fixed using the nut 84. For such unloading of the ground anchor 80A, for example, a tension jack is attached to the screw structure portion 82, the ground anchor 80A is tensioned with a load larger than the residual tensile force, and the nut 84 is lifted from the bearing plate 86. This is done by loosening the nut 84 released from the load acting state.

On the other hand, as another long construction member that prestresses the construction position like the ground anchor, a civil engineering tie rod 80B as shown in FIG. 24 can be mentioned. The civil engineering tie rod 80B was fixed with a nut 84 on the receiving side (right side in FIG. 24) with a nut 84 and on the tension side (left side in FIG. 24) with a tension jack. It is a thing. Even for such a civil engineering tie rod 80B, if the residual tensile force exceeds the allowable tensile force, it is necessary to unload the load. To unload the civil engineering tie rod 80B, for example, a tension jack is attached to the screw structure 82 on the tension side, the civil engineering tie rod 80B is tensioned with a load larger than the remaining tensile force, and the nut 84 is lifted from the bearing plate 86. In this state, it is performed by loosening the nut 84 released from the load acting state.

Japanese Unexamined Patent Publication No. 06-248649 Japanese Unexamined Patent Publication No. 2016-006263

Here, the above-mentioned conventional unloading method for the ground anchor 80A of the "nut fixing method" or the tie rod 80B for civil engineering has the following restrictions. First, the load applied by the tension jack for unloading must be less than or equal to the allowable load of the ground anchor 80A and the civil engineering tie rod 80B at the time of tension. Therefore, when the residual tensile force exceeds the permissible load at the time of tension, the nut cannot be tensioned with a load larger than the residual tensile force, and the nut 84 cannot be lifted and loosened. Next, the length (tension surplus length) L of the screw structure portion 82 protruding from the nut 84 must be long enough to attach the tension jack (for example, a length equal to or greater than the thickness of the nut 84). It doesn't become. For example, for the civil engineering tie rod 80B, when there is not enough space on the tension side to set the tension jack because the building structure was built in the immediate vicinity of the tension side, it is necessary to tension the receiving side with the tension jack. There may not be enough tension left on the receiving side.

When the ground anchor 80A in a tense state or the civil engineering tie rod 80B in a tense state cannot be tensioned beyond the allowable load due to the above restrictions, for example, the following unloading method is performed. Will be. For ground anchors 80A that are in tension, a method for displacing the pressure receiving plate 88 by drilling the ground G of the back of the pressure receiving plate 88 on the rear side, the head and middle section gas blowing of the ground anchor 80A which is in tension, etc. For the civil engineering tie rod 80B in a tense state, a method of breaking the pedestal 88, the abdominal raising material 90, etc., and cutting the head of the civil engineering tie rod 80B in a tense state by gas fusing or the like. The method of doing this can be mentioned. However, all of these methods are difficult to adopt from the viewpoint of ensuring the safety of workers and because the cut ground anchor 80A and the civil engineering tie rod 80B cannot be used.

The present invention has been made in view of the above problems, and an object of the present invention is to unload a long construction member so that it can be reused even if it is restricted by an allowable load and a tension surplus length. be.

(Aspect of the invention)
The following aspects of the invention exemplify the configurations of the present invention, and will be described separately in order to facilitate understanding of the various configurations of the present invention. Each section does not limit the technical scope of the present invention, and while taking into consideration the best mode for carrying out the invention, some of the components of each section are replaced, deleted, or further others. Those to which the above-mentioned components are added can also be included in the technical scope of the present invention.

(1) At least one end of a screw structure that is used to apply prestress to the construction position by tension and is fixed to the surface of the construction position in a tension state using a nut via a pressure plate. A wrench for rotating the nut in a tense state and an end of the wrench on the side opposite to the side that engages with the nut can be attached and detached. A rotating jack having a shaft attachment portion that is pivotally supported, and a fixing member for fixing the rotating jack to the bearing plate so that the expansion and contraction motion of the rotating jack can be converted into the rotational motion of the wrench. JoniSo location, including, and.

The unloading device described in this section includes a wrench, a rotating jack, and a fixing member, and the wrench is in a tense state in which the screw structure portion of the long construction member is fixed to the surface of the construction position. It is for engaging with the nut and rotating the nut in a tense state. The rotary jack, for example, uses hydraulic pressure to perform expansion and contraction movements, and has a shaft attachment portion that detachably supports the end portion of the wrench on the side opposite to the side that engages with the nut. Further, the fixing member is for fixing the rotary jack to the bearing plate used for tension fixing of the long construction member. At this time, the expansion / contraction motion of the rotary jack is the rotational motion of the wrench. The rotating jack is fixed to the bearing plate so that it can be converted to. That is, the rotary jack is fixed to the bearing plate by a fixing member, and the wrench in a state of being engaged with the nut and pivotally supported by the axle attachment portion of the rotating jack by the expansion and contraction movement of the bearing plate is used. Rotate as a reaction force.

With the above configuration, the unloading device described in this section uses the expansion and contraction movement of the rotating jack to attach a nut that tension- fixes a long construction member to the surface of the construction position via a bearing plate. , It will be forcibly rotated. For this reason, by forcibly rotating the nut in a tense state in the direction of loosening, the tension force of the long construction member is reduced and the load is removed without tensioning the long construction member by the tension jack. Become. That is, even if the tension margin required for tension by the tension jack cannot be secured or the residual tensile force exceeds the allowable load , the long construction member is removed without being affected by these restrictions. Be loaded. Moreover, since it is not necessary to cut the long construction member, the long construction member is reused even after unloading.

(2) In the above item (1), in the rotary jack, a plurality of shaft-attached portions are linearly arranged in the expansion / contraction direction of the rotary jack at an arrangement interval within the stroke range of the rotary jack. Unloading device (claim 1 ).
In the unloading device described in this section, the rotary jack is provided with a plurality of shaft-attached portions on which the end of the wrench is detachably supported so as to be linearly arranged in the expansion / contraction direction of the rotary jack. , The arrangement interval of the adjacent shaft attachment portions is equal to the difference in length between the stroke range of the rotating jack, for example, the maximum stroke and the minimum stroke. In this case, the positions of the two adjacent shaft-mounted portions on the extension direction side and the contraction direction side of the rotation jack rotate when the rotation jack has the maximum stroke. It is the same as the position of the shaft attachment part on the extension direction side when the jack is at the minimum stroke. Therefore, when using a rotating jack and a wrench to rotate a nut in a tense state of a long construction member, the work is performed in the following procedure.

That is, first, with the end of the wrench pivotally supported by the shaft attachment portion located on the most contraction direction side of the rotation jack, the wrench is engaged with the nut in the tension state of the long construction member for rotation. Extend the jack to the maximum stroke and rotate the nut. Then, with the wrench still engaged in the nut, remove the end of the wrench from the shaft attachment, shrink the rotating jack to the minimum stroke, and then remove the end of the wrench from the removed shaft attachment. Axial support is provided to the shaft attachment portion adjacent to the extension direction side of the rotary jack. After that, in the same procedure as above, the nut is rotated by expanding and contracting the rotating jack while sequentially changing the shaft-attached portion that pivotally supports the end of the wrench toward the extension direction side of the rotating jack. As a result, the nut in a tense state can be efficiently rotated by utilizing the plurality of shaft-attached portions arranged in a straight line of the rotating jack while saving the trouble of changing the wrench to the nut as much as possible. After rotating the nut to the maximum stroke of the rotary jack with the end of the wrench pivotally supported by the shaft attachment portion on the most extending direction side of the rotary jack, if necessary, the wrench The end portion may be repositioned to the shaft attachment portion on the most contraction direction side of the rotating jack, and the wrench may be hung on the nut.

(3) In the above items (1) and (2), the tension bar, the connecting member connecting the tension bar and the screw structure portion of the long construction member, and the tension bar and the connecting member are used. The tension jack for pulling the construction long member with a load equal to or less than the allowable load of the long construction member, and the tension jack are placed with the tension bar and the connecting member inserted inside. A cylindrical chair member and at least one raising member installed between the pressure plate and the chair member so that the chair member is arranged at a height located around the connecting member. Unloading device including (claims 2 and 3).

The unloading device described in this section is used when the screw structure portion of the long construction member has a tension extra length required for tensioning the long construction member with a tension jack. Includes bars, connecting members, tension jacks, chair members, and at least one raising member. The tension bar is connected to the tip of the threaded structure by a connecting member, and the connecting member is provided with a threaded groove corresponding to the threaded groove of the threaded structure of the long construction member on the inner peripheral portion on one end side. It has a female screw structure. Further, a cylindrical chair member and a tension jack are placed on at least one raising member installed on the bearing plate. At this time, the tension bar and the connecting member are inserted into the cylindrical chair member, and at least one raising member is positioned around the connecting member in order to secure an operating space for the connecting member. The quantity to be installed is adjusted so that it is placed at the desired height.

In such an installation state, the tension bar is tensioned by the tension jack, so that the long construction member in the tension state is tensioned by the residual tensile force via the tension bar and the connecting member. Further, since the tension jack is for tensioning the long construction member with a load equal to or less than the allowable load of the long construction member, there is a particular problem even when the residual tensile force exceeds the allowable load. There is no tension in the long construction members. Due to the tension of the long construction member, the load acting between the nut and the bearing plate is reduced to the difference between the residual tensile force of the long construction member and the load due to the tension of the tension jack. Therefore, the long construction member is strained by the tension jack, and the nut in the tension state of the long construction member is rotated while the load equal to or less than the allowable tensile force by the tension jack is applied as an auxiliary action. Wear of nuts and bearing plates due to frictional force is reduced. As a result, the nut and the bearing plate can be reused in a state where the wear is reduced.

(4) In the above items (2) and (3), the at least one raising member has an annular shape in a plan view, and is provided with a notch so as to avoid an operation region of the rotational movement of the wrench. Unloading device (claim 4).
In the unloading device described in this section, the raising member for adjusting the height position of the chair member forms an annular shape in a plan view, and a notch is provided so as to avoid the operating region of the rotational movement of the wrench. It is something that is. That is, the raising member has a C-shape, a U-shape, or the like in a plan view, and a space for arranging the screw structure or the like is secured inside. As a result, the raising member, which is installed between the bearing plate and the chair member and is arranged around the nut in the tensioned state in contact with the bearing plate, rotates the nut in the tensioned state. The reaction force of the tension caused by the tension jack is transmitted from the chair member to the bearing plate without hindering the rotational movement of the wrench.

(5) In the above items (2) to (4), the nut member attached to the screw structure portion between the nut and the connecting member at a position where the connecting member comes into contact with the end on the nut side. (Claim 5), wherein a rotation stopper for preventing rotation of the connecting member is provided inside the chair member.
The unloading device described in this section includes a nut member between a connecting member attached to the tip of the screw structure portion and a nut for tension-fixing the screw structure portion in order to connect the tension bar. .. This nut member is attached at a position where it comes into contact with the end on the nut side of the connecting member, and together with the connecting member having a female screw structure corresponding to the screw structure portion of the long construction member, the so-called double nut rotation restraining effect causes the nut member. The connecting member is prevented from coming off from the screw structure portion.

Further, the unloading device described in this section restrains the connecting member in the rotation direction by providing a rotation stopper inside the chair member to prevent the connecting member from rotating. The restraint of the connecting member and the effect of suppressing the rotation of the double nut by the nut member prevent the screw structure portion from rotating together with the nut. As a result, when the nut is rotated by the wrench, the screw structure portion does not rotate together with the nut, so that the breakage of the PC steel wire or the like inside the screw structure portion due to the co-rotation is prevented.

(6) In the above items (2 ) to (5), the outer peripheral portion of at least one raising member and the outer peripheral portion of the chair member centered on the positions of the screw structure portion and the tension bar, respectively. (Claim 6), wherein a ring portion is provided, and a pole member is inserted through the ring portion of the at least one raising member and the ring portion of the chair member (claim 6).
In the unloading device described in this section, ring portions are provided on the outer peripheral portion of the raising member and the outer peripheral portion of the chair member, respectively, centering on the positions of the screw structure portion and the tension bar, and the ring of the raising member is provided. A pole member is inserted through the portion and the ring portion of the chair member. That is, the pole member is inserted into both the ring portions of the raising member and the chair member, so that there is a gap between the raising member and the chair member, and when a plurality of raising members are installed, between all the raising members. It also prevents the deviation of the chair. As a result, the unloading work is performed while the raising member and the chair member are arranged at appropriate positions.

(7) In the above (1) to (6), the unloading device (claim 7) in which the long construction member is a ground anchor in a tense state or a tie rod in a tense state.
Unloading apparatus according to the above long construction members unloading target, that is the tie rod on the ground anchor or tension in tension, a ground anchor or tie rods prestress is given, The load is removed while performing the actions described in the above items (1) to (6). The tie rod in this case means a tie rod for civil engineering or earth retaining.

(8) At least one end of a screw structure that is used to apply prestress to the construction position by tension and is fixed to the surface of the construction position in a tensioned state using a nut via a pressure plate. This is a method of unloading a long construction member, which is provided in the above method, in which a wrench is engaged with the nut, and the nut of the wrench is attached to a shaft-attached portion of a rotary jack fixed to the bearing plate via a fixing member. The end on the opposite side to the engaging side is detachably supported by the shaft, and the expansion and contraction of the rotation jack is used to apply a rotational force to the nut via the wrench using the pressure plate as a reaction force. Then, the nut in a tense state is rotated in the direction of loosening , and at this time, as the rotation jack, the shaft attachment portion expands and contracts the rotation jack at an arrangement interval within the stroke range of the rotation jack. The nut is rotated while sequentially changing the shaft attachment portion that pivotally supports the end portion of the wrench to the extension direction side of the rotation jack by utilizing a plurality of those arranged linearly in the direction. Unloading method (claim 8).

The unloading method described in this section is to loosen the nut, which tension-fixes the long construction member on the surface of the construction position via the bearing plate, via the wrench by using the expansion and contraction of the rotating jack. It is forcibly rotated. Therefore, the tension force of the long construction member is reduced and the load is removed without tensioning the long construction member by the tension jack. That is, when the tension surplus length required for tension by the tension jack cannot be secured in the screw structure portion in the tension state of the long construction member, or the residual tensile force of the long construction member exceeds the allowable load. Even in this case, the long construction member is unloaded. Further, since it is not necessary to cut the long construction member, the long construction member is reused even after unloading. Further, as the rotation jack, a rotation jack is used in which a plurality of shaft-attached portions are arranged linearly in the expansion / contraction direction of the rotation jack at an arrangement interval within the stroke range of the rotation jack. Then, when rotating the nut, the nut is rotated by expanding and contracting the rotating jack while sequentially changing the shaft-attached portion that pivotally supports the end of the wrench toward the extension direction side of the rotating jack. As a result, the nut can be rotated efficiently by utilizing the plurality of shaft-attached portions arranged in a straight line of the rotating jack while saving the trouble of changing the wrench to the nut as much as possible.

(9) In the above item (8), the tension jack is attached to at least one end of the long construction member, and the long construction member is allowed in the direction in which the tension jack pulls the long construction member. A unloading method (claim 9) in which the nut in a tense state is rotated while applying a load equal to or less than the load.
Unloading method according to the above, the screw structure portion of the elongated construction member in a tense state, used when the tension excess length required in order to re-tension the elongated construction member in tension jack is ensured First, a tension jack is attached to the screw structure part that has a tension margin. Then, the tension jack is in a tense state while applying a load equal to or less than the allowable tensile force of the long construction member in the direction of pulling the long construction member, that is, in the direction opposite to the residual tensile force of the long construction member. It rotates the nut.

Therefore, even when the residual tensile force exceeds the allowable load , there is no particular problem and the long construction member is tensioned and the load is applied in the direction opposite to the residual tensile force. Due to the tension of the long construction member, the load acting between the nut and the bearing plate is reduced to the difference between the residual tensile force of the long construction member and the load in the opposite direction due to the tension of the tension jack. Accordingly, tension jack by tensing the long construction member in a tense state, while a load of less than the allowable load by tensioning the jack supplementarily reacted, by rotating the nut on the tension of the elongate construction member, a nut Wear of nuts and bearing plates due to frictional force during rotation is reduced. As a result, after unloading the long construction member, the nut and the bearing plate can be reused in a state where the wear is reduced.

(10) In the above (8) and (9), the unloading method (claim 10) in which the long construction member is a ground anchor in a tense state or a tie rod in a tense state.
In the unloading method described in this section, the long construction member to be unloaded is a ground anchor or tie rod in a tense state, so that the ground anchor or tie rod to which prestress is applied can be used. The load is removed while performing the actions described in the above items (8) and (9). The tie rod in this case means a tie rod for civil engineering or earth retaining, as in the above item (7).

Since the present invention has the above-described configuration, it is possible to re-load the long construction member even if it is restricted by the allowable load and the tension surplus length.

It is a wrench included in the unloading device according to the first embodiment of the present invention. It is a rotary jack included in the unloading device according to the first embodiment of the present invention. A part of the fixing member included in the unloading device according to the first embodiment of the present invention is shown. A part of the fixing member included in the unloading device according to the first embodiment of the present invention, which is different from FIG. 3, is shown. It is an image diagram for demonstrating the unloading method using the unloading apparatus which concerns on 1st Embodiment of this invention. Continuing from FIG. 5, it is an image diagram for demonstrating the unloading method using the unloading apparatus according to the 1st Embodiment of this invention. Continuing from FIG. 6, it is an image diagram for demonstrating the unloading method using the unloading apparatus which concerns on 1st Embodiment of this invention. Continuing from FIG. 7, it is an image diagram for demonstrating the unloading method using the unloading apparatus according to the 1st Embodiment of this invention. Continuing from FIG. 8, it is an image diagram for demonstrating the unloading method using the unloading apparatus which concerns on 1st Embodiment of this invention. Continuing from FIG. 9, it is an image diagram for demonstrating the unloading method using the unloading apparatus according to the 1st Embodiment of this invention. The tension bar included in the unloading device according to the second embodiment of the present invention is shown. A connecting member included in the unloading device according to the second embodiment of the present invention is shown. The nut member included in the unloading apparatus according to the second embodiment of the present invention is shown. The chair member included in the unloading apparatus according to the 2nd Embodiment of this invention is shown. A raising member included in the unloading device according to the second embodiment of the present invention is shown. It is an image diagram for demonstrating the unloading method using the unloading apparatus which concerns on 2nd Embodiment of this invention. Continuing from FIG. 16, it is an image diagram for demonstrating the unloading method using the unloading apparatus which concerns on the 2nd Embodiment of this invention. Continuing from FIG. 17, it is an image diagram for demonstrating the unloading method using the unloading apparatus which concerns on the 2nd Embodiment of this invention. Continuing from FIG. 18, it is an image diagram for demonstrating the unloading method using the unloading apparatus according to the 2nd Embodiment of this invention. Continuing from FIG. 19, it is an image diagram for demonstrating the unloading method using the unloading apparatus according to the 2nd Embodiment of this invention. Continuing from FIG. 20, it is an image diagram for demonstrating the unloading method using the unloading apparatus which concerns on the 2nd Embodiment of this invention. Continuing from FIG. 21, it is an image diagram for demonstrating the unloading method using the unloading apparatus according to the 2nd Embodiment of this invention. It is an image figure which shows the vicinity of the head of a ground anchor. It is an image figure which shows the vicinity of both ends of the tie rod for civil engineering.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. Here, the same parts or corresponding parts are indicated by the same reference numerals throughout the drawings.
The unloading device 10 (see FIGS. 8 to 10) according to the first embodiment of the present invention is located at the construction position of the ground anchor 80A shown in FIG. 23, the civil engineering tie rod 80B shown in FIG. 24, and the like. It unloads the long construction member 80 that is prestressed, and includes each component as shown in FIGS. 1 to 4.
The wrench 12 shown in FIG. 1 is for rotating the nut 84 (see FIGS. 23 and 24) in a tense state of the long construction member 80, and has an engaging portion 12a that engages with the nut 84 and a later-described portion. It has a shaft support end 12b that is shaft-supported by a rotating jack. The shaft support end 12b is provided with a hole 12c through which a connection pin is inserted when the shaft is supported by the rotation jack.

In this embodiment, the rotary jack 14 shown in FIG. 2 is operated by a hydraulic pump, and expands and contracts by hydraulic pressure. The rotary jack 14 is composed of a cylinder portion 14a having a shaft support end 14c pivotally supported by a fixing member described later, and a ram portion 14b that is displaced from the cylinder portion 14a by the expansion / contraction motion of the rotary jack 14. .. The ram portion 14b is provided with a plurality of shaft-attached portions 16 (three in this embodiment) forming through holes for pivotally supporting the wrench 12 shown in FIG. 1. That is, when the wrench 12 is pivotally supported in each shaft attachment portion 16, the shaft attachment portion 16 and the hole 12c of the wrench 12 are arranged in a state where the shaft support end 12b of the wrench 12 is arranged in the internal space C1 of the ram portion 14b. A pin for connection is inserted in both of the and. These three shaft-attached portions 16 are arranged linearly in the expansion / contraction direction of the rotation jack 14, and the distance between the adjacent shaft-attached portions 16 is set within the stroke range of the rotation jack 14. In this embodiment, the distance between the adjacent shaft-attached portions 16 is equal to the difference S in length between the maximum stroke and the minimum stroke of the rotary jack 14. Further, the shaft support end 14c is provided with a hole 14d through which a fixing pin is inserted when the shaft is supported by the fixing member.

Next, the reaction force frame 20 shown in FIG. 3 and the extension member 22 shown in FIG. 4 are attached to the bearing plate 86 (see FIGS. 23 and 24) used for fixing the long construction member 80. It constitutes a fixing member 18 for fixing the rotary jack 14. The reaction force frame 20 is a frame member that is covered and fixed on the bearing plate 86, and the main body portion 20a is provided with a window portion 20b having a size for accommodating the bearing plate 86 and is used when combined with the extension member 22. Four holes 20h are provided. Further, the main body 20a is provided with restricting members 20c to 20e for restricting movement from the bearing plate 86 when fixed to the bearing plate 86, and insertion members 20f and 20g through which fixing bolts described later are inserted. Has been done.

On the other hand, the extension member 22 is composed of a main body portion 22a and a jack mounting portion 22b, and the main body portion 22a has four ribs 22c for reinforcement and four used when the reaction force frame 20 is combined. A hole 22d is provided. Further, the jack mounting portion 22b is provided with a through hole 22e for axially supporting the rotating jack 14 shown in FIG. That is, when the rotation jack 14 is attached to the jack attachment portion 22b, the through hole 22e and the rotation jack 14 are arranged in the state where the shaft support end 14c of the rotation jack 14 is arranged in the internal space C2 of the jack attachment portion 22b. A fixing pin is inserted into both the hole 14d and the hole 14d. The reaction force frame 20 and the extension member 22 constituting the fixing member 18 are aligned and overlapped so that the four holes 20h of the reaction force frame 20 and the four holes 22d of the extension member 22 overlap each other. Bolts are inserted and combined every 20h and 22d holes.

Subsequently, with reference to FIGS. 5 to 10, the procedure for installing the unloading device 10 according to the first embodiment of the present invention and the unloading method using the unloading device 10 will be described. In addition, in FIGS. 5 to 7, the long construction member 80 and the unloading device 10 in a tense state are shown from the plane direction and the front direction, and in FIGS. The unloading device 10 is shown only in the plane direction.
First, FIG. 5 shows the vicinity of the head of the long construction member 80 to be unloaded. Similar to the ground anchor 80A and the civil engineering tie rod 80B shown in FIGS. 23 and 24, the long construction member 80 uses a nut 84 on the surface of the construction position via the bearing plate 86 to form a screw structure (apartment). ) 82 is tense and fixed. The black mark attached to the nut 84, which can be confirmed in FIG. 5A, is attached to clearly show how the nut 84 rotates, and the nut 84 shown in FIGS. 6 to 10 is shown. It is also attached to.

Then, as shown in FIG. 6, the reaction force frame 20 of the fixing member 18 shown in FIG. 3 is installed on the long construction member 80 in the tension state as described above. Specifically, the reaction force frame 20 is placed on the bearing plate 86 on the left side in FIG. 6 so that the bearing plate 86 is arranged between the regulating member 20c and the regulating member 20d. Is slid to the right side in FIG. 6 so that the bearing plate 86 fits in the window portion 20b of the reaction force frame 20.
Next, as shown in FIG. 7, on the back surface of the bearing plate 86, the fixing bolts 24 are inserted into both the insertion member 20f and the insertion member 20g of the reaction force frame 20 and fixed with nuts. As a result, the reaction force frame 20 is firmly fixed to the bearing plate 86. The structure and method of fixing the reaction force frame 20 to the bearing plate 86 are not limited to the structures and methods shown in FIGS. 3 and 7, depending on the situation of the long construction member 80 to be unloaded. Appropriate fixing structures and fixing methods are adopted accordingly.

Subsequently, as shown in FIG. 8A, the reaction force frame 20 and the extension member 22 are combined to form the fixing member 18. Specifically, the main body portion 22a of the extension member 22 is placed on the main body portion 20a of the reaction force frame 20 so that the four holes 20h of the reaction force frame 20 and the four holes 22d of the extension member 22 are aligned. Are overlapped, and bolts are inserted into and fixed to the holes 20h and 22d, respectively.
Then, as shown in FIG. 8B, the rotation jack 14 is attached to the jack attachment portion 22b of the extension member 22. That is, as described above, the shaft support end 14c of the rotary jack 14 is arranged in the internal space C2 (see FIG. 4A) of the jack mounting portion 22b, and the through hole 22e of the extension member 22 and the rotary jack 14 are arranged. The fixing pin 26 is inserted into both the hole 14d (see FIG. 2), and the rotating jack 14 is pivotally attached to the jack mounting portion 22b. As a result, the rotation jack 14 can rotate with respect to the fixing member 18 with the fixing pin 26 as the rotation axis. From here on, for convenience of explanation, the three shaft-attached portions 16 provided on the ram portion 14b of the rotary jack 14 will be referred to as the shaft-attached portions 16a to 16c in order from the cylinder portion 14a.

Next, as shown in FIG. 8C, the engaging portion 12a of the wrench 12 is engaged with the nut 84 in a tense state of the long construction member 80, and the shaft support end 12b of the wrench 12 is rotated. The jack 14 is pivotally supported by the shaft attachment portion 16a located closest to the cylinder portion 14a. That is, as described above, the shaft attachment portion 16a and the shaft support end are arranged in the internal space C1 (see FIG. 2B) of the ram portion 14b of the rotation jack 14 by arranging the shaft support end 12b of the wrench 12. By inserting the connection pin 28 into both the hole 12c (see FIG. 1) provided in the 12b, the wrench 12 is pivotally supported by the shaft attachment portion 16a. At this time, it is preferable that the stroke of the rotary jack 14 is most contracted within a range in which the wrench 12 can be engaged with the nut 84 and the wrench 12 can be axially attached to the shaft attachment portion 16a. As a result, the wrench 12 can rotate with respect to the rotation jack 14 with the connection pin 28 as the rotation axis. By the procedure up to FIG. 8C, each component of the unloading device 10 according to the first embodiment of the present invention is assembled.

Then, as shown in FIG. 9A, the rotary jack 14 is extended to the maximum stroke by using a hydraulic pump (not shown). Then, due to the rotation of the rotary jack 14 with respect to the fixing member 18 and the rotation of the wrench 12 with respect to the ram portion 14b of the rotary jack 14, the extension motion of the rotary jack 14 is counterclockwise with respect to the bearing plate 86. Is converted into the rotational motion of. Therefore, the nut 84 in the tense state in which the wrench 12 is engaged is rotated in the direction of loosening with respect to the bearing plate 86.

Subsequently, the connection pin 28 is pulled out from the shaft attachment portion 16a of the rotation jack 14, and the shaft support of the wrench 12 in the shaft attachment portion 16a is released, and the rotation jack 14 is contracted to the minimum stroke by using a hydraulic pump. .. Then, since the distance between the shaft-attached portion 16a and the shaft-attached portion 16b adjacent thereto is equal to the length difference S (see FIG. 2) between the maximum stroke and the minimum stroke of the rotary jack 14, the nut 84 The position of the hole 12c (see FIG. 1) of the wrench 12 that remains engaged with the rotary jack 14 coincides with the position of the shaft-attached portion 16b of the rotating jack 14. Therefore, as shown in FIG. 9B, the connection pin 28 is inserted through both the shaft-attached portion 16b and the hole 12c of the wrench 12, and the wrench 12 is pivotally supported by the shaft-attached portion 16b.

Then, as shown in FIG. 9C, the rotary jack 14 is extended to the maximum stroke by using a hydraulic pump, and the extension motion of the rotary jack 14 is changed to the counterclockwise rotary motion of the wrench 12 with respect to the bearing plate 86. And the nut 84 in a tense state is further rotated in the loosening direction.
Further, the connection pin 28 is pulled out from the shaft attachment portion 16b of the rotation jack 14, and the shaft support of the wrench 12 in the shaft attachment portion 16b is released, and the rotation jack 14 is contracted to the minimum stroke by using a hydraulic pump. Then, the distance between the shaft-attached portion 16b and the shaft-attached portion 16c adjacent thereto is also equal to the length difference S (see FIG. 2) between the maximum stroke and the minimum stroke of the rotary jack 14, so that the nut 84 The position of the hole 12c (see FIG. 1) of the wrench 12 that remains engaged with the rotary jack 14 coincides with the position of the shaft attachment portion 16c of the rotating jack 14. Therefore, as shown in FIG. 10A, the connection pin 28 is inserted into both the shaft-attached portion 16c and the hole 12c of the wrench 12, and the wrench 12 is pivotally supported by the shaft-attached portion 16c.

Then, as shown in FIG. 10B, the rotary jack 14 is extended to the maximum stroke by using a hydraulic pump, and the extension motion of the rotary jack 14 is changed to the counterclockwise rotary motion of the wrench 12 with respect to the bearing plate 86. And the nut 84 in a tense state is further rotated in the loosening direction.
After that, as shown in FIG. 10 (c), the connection pin 28 is pulled out from the shaft attachment portion 16c of the rotary jack 14, the shaft support of the wrench 12 in the shaft attachment portion 16c is released, and the wrench 12 is removed from the nut 84. Remove.
After that, until the load acting on the nut 84 (residual tensile force) becomes equal to or less than the allowable load of the long construction member 80, the procedures shown in FIGS. 8 (c) to 10 (c) are repeatedly executed. The long construction member 80 is unloaded.

Now, according to the first embodiment of the present invention having the above configuration, it is possible to obtain the following effects. That is, the unloading device 10 according to the first embodiment of the present invention includes a wrench 12, a rotating jack 14, and a fixing member 18 as shown in FIGS. 1 to 4. The wrench 12 is used to rotate the nut 84 by engaging the screw structure portion 82 of the long construction member 80 with the nut 84 that is tension- fixed to the surface of the construction position, as shown in FIGS. 23 and 24. It is a thing. The rotary jack 14 uses, for example, hydraulic pressure to perform expansion and contraction movements, and detachably supports the shaft support end 12b of the wrench 12 on the opposite side of the engaging portion 12a that engages with the nut 84. It has a shaft attachment portion 16.

Further, the fixing member 18 composed of the reaction force frame 20 shown in FIG. 3 and the extension member 22 shown in FIG. 4 is a jack for rotation with respect to the bearing plate 86 used for fixing the long construction member 80. It is for fixing 14. At this time, as can be confirmed in FIGS. 8 (c) to 10 (b), the rotary jack 14 can be converted into the rotary motion of the wrench 12 with respect to the bearing plate 86. Is fixed. That is, the rotary jack 14 is fixed to the bearing plate 86 by the fixing member 18, and is engaged with the nut 84 by its expansion / contraction motion and is pivotally supported by the shaft attachment portion 16 of the rotary jack 14. The wrench 12 is rotated by using the bearing plate 86 as a reaction force.

With the above configuration, the unloading device 10 according to the first embodiment of the present invention has a nut 84 in which a long construction member 80 is tension-fixed to the surface of the construction position via a bearing plate 86. It can be forcibly rotated by utilizing the expansion / contraction movement of the rotation jack 14. Therefore, by forcibly rotating the nut 84 in the tensioned state in the direction of loosening, the tension force of the long construction member 80 is reduced and the load is removed without tensioning the long construction member 80 by the tension jack. It becomes possible to do. That is, even when the tension margin required for tension by the tension jack cannot be secured or the residual tensile force exceeds the allowable load , the long construction member 80 is not affected by these restrictions. Can be unloaded. Moreover, since it is not necessary to cut the long construction member 80, the long construction member 80 can be reused even after unloading.

Further, in the unloading device 10 according to the first embodiment of the present invention, as shown in FIG. 2, the shaft support end 12b of the wrench 12 is detachably supported by the rotary jack 14. A plurality of shaft attachment portions 16 (three in the example of FIG. 2) are provided so as to be linearly arranged in the expansion / contraction direction of the rotation jack 14. Further, in those shaft-attached portions 16, the arrangement interval of the adjacent shaft-attached portions 16 is within the stroke range of the rotation jack 14, and in the example of FIG. 2, the difference S between the maximum stroke and the minimum stroke is equal. It has become. In this case, the two adjacent shaft-attached portions 16 on the extension direction side and the contraction direction side of the rotation jack 14 are the shaft-attached portions 16 on the contraction direction side when the rotation jack 14 has the maximum stroke. The position is the same as the position of the shaft attachment portion 16 on the extension direction side when the rotation jack 14 has the minimum stroke. Therefore, when rotating the nut 84 of the long construction member 80 by using the rotating jack 14 and the wrench 12, the work is performed in the following procedure.

That is, first, as shown in FIG. 8C, the wrench 12 is lengthened with the shaft support end 12b of the wrench 12 pivotally supported by the shaft attachment portion 16a located on the most contraction direction side of the rotation jack 14. Engage with the nut 84 of the wrench construction member 80, extend the rotation jack 14 to the maximum stroke, and rotate the nut 84 as shown in FIG. 9A. Subsequently, with the wrench 12 still engaged with the nut 84, the shaft support end 12b of the wrench 12 is removed from the shaft attachment portion 16a, and the rotary jack 14 is contracted to the minimum stroke. Since the distance from the shaft attachment portion 16b is equal to the difference S between the maximum stroke and the minimum stroke of the rotary jack 14, the position of the shaft support end 12b of the wrench 12 coincides with the position of the shaft attachment portion 16b. .. Therefore, as shown in FIG. 9B, with the wrench 12 still engaged with the nut 84, the shaft support end 12b of the wrench 12 is pivotally supported by the shaft attachment portion 16b of the rotation jack 14. Can be done.

After that, in the same procedure as above, the rotary jack 14 is expanded and contracted while sequentially changing the shaft attachment portion 16 that pivotally supports the shaft support end 12b of the wrench 12 in the extension direction side of the rotary jack 14. , Rotate the nut 84. As a result, it is possible to efficiently rotate the nut 84 by using the plurality of shaft-attached portions 16 arranged in a straight line of the rotation jack 14 while saving the trouble of changing the wrench 12 to the nut 84 as much as possible. Become. As shown in FIG. 10B, the maximum stroke of the rotary jack 14 is supported by the shaft support end 12b of the wrench 12 being pivotally supported by the shaft attachment portion 16c on the most extending direction side of the rotary jack 14. After rotating the nut 84 to, if necessary, the shaft support end 12b of the wrench 12 is re-shafted to the shaft attachment portion 16a on the most contraction direction side of the rotation jack 14, and the wrench 12 is supported by the nut 84. You can change it to.

Here, the unloading device 10 according to the first embodiment of the present invention is in the state of FIGS. 9 (a) to 9 (b) or when the state of FIGS. 9 (c) to 10 (a) is obtained. When the state is reached, the connection pin 28 is replaced to support the shaft support end 12b of the wrench 12 with each shaft attachment portion 16 of the rotation jack 14. During this replacement work, since the rotation of the nut 84 by the wrench 12 is stopped, the acting load and the twist of the long construction member 80 in the tense state do not change. Therefore, the operator can replace the connection pin 28 without fear of breaking the long construction member 80.

Further, the unloading device 10 according to the first embodiment of the present invention is in the state of FIGS. 8 (c) to 9 (a), the state of FIGS. 9 (b) to 9 (c), or the state of FIGS. 9 (c). Until the rotation jack 14 is fully extended by one stroke, such as when the state from 10 (a) to 10 (b) is reached, that is, when the nut 84 is rotating, the operator approaches and performs the work. You don't have to do it. Therefore, the operator can evacuate at the timing when the acting load or the twist of the long construction member 80 changes.
Then, in the unloading method using the unloading device 10 according to the first embodiment of the present invention, the long construction member 80 is unloaded by the procedure shown in FIGS. 8 (c) to 10 (b). By performing the above, the same operation and effect as that of the unloading device 10 according to the first embodiment of the present invention can be obtained.

Next, the unloading device 10'(see FIGS. 20 to 22) according to the second embodiment of the present invention will be described with reference to FIGS. 11 to 22. In FIGS. 16 to 22, the same parts as or corresponding to the unloading device 10 according to the first embodiment of the present invention are designated by the same reference numerals. It should be noted that the unloading device 10 ′ according to the second embodiment of the present invention will be described only in the difference from the unloading device 10 according to the first embodiment of the present invention. The description of the configuration and operation / effect of the same portion as that of the unloading device 10 according to the first embodiment will be omitted.

The unloading device 10'according to the second embodiment of the present invention has the ground anchor 80A shown in FIG. 23, the tension side of the civil engineering tie rod 80B shown in FIG. 24 (left side in the drawing), and the like. It is used when the screw structure portion 82 is secured with a tension surplus length L that allows the long construction member 80 to be tensioned by the tension jack described later. Then, in addition to each component included in the unloading device 10 according to the first embodiment of the present invention shown in FIGS. 1 to 4, each component as shown in FIGS. 11 to 15 is included. I'm out.
First, the tension bar 40 shown in FIG. 11 is a member that is connected to the screw structure portion 82 of the long construction member 80 in a tense state and is directly pulled by the tension jack, and is to be connected to the long construction member 80. The screw groove portion 40a and the screw groove portion 40b for fixing to the tension jack side are provided.

The connecting member 42 shown in FIG. 12 connects the tension bar 40 and the screw structure portion 82 of the long construction member 80, and the hexagonal column portion 42a on the left side and the cylindrical portion 42b on the right side in FIG. 12B. It is composed of and. A screw hole 42c provided with a screw groove corresponding to the screw groove portion 40a of the tension bar 40 is provided inside the hexagonal column portion 42a so as to open on the left side in FIG. 12B. Further, a screw hole 42d provided with a screw groove corresponding to the screw groove of the screw structure portion 82 of the long construction member 80 from the inside of the cylindrical portion 42b to the inside of the hexagonal column portion 42a is on the right side in FIG. 12B. It is provided with an opening in.

The nut member 44 shown in FIG. 13 is a member screwed into the screw structure portion 82, and is a connecting member 42 in a state where the tension bar 40 and the screw structure portion 82 of the long construction member 80 are connected, and the long construction. The screw structure portion 82 of the member 80 is screwed into the nut 84 that is tension- fixed at a position where it comes into contact with the cylindrical portion 42b of the connecting member 42. That is, the nut member 44 is a member for obtaining the effect of suppressing the rotation of the double nut with the connecting member 42. The nut member 44 has a columnar shape having substantially the same outer diameter as the columnar portion 42b of the connecting member 42, and is provided with a screw groove corresponding to the thread groove of the screw structure portion 82 of the long construction member 80. It has. Further, the nut member 44 may be provided with a plurality of horizontal holes so that the set screw can be tightened.

In the chair member 46 shown in FIG. 14, a tension jack is placed in a state where the tension bar 40 and the connecting member 42 are inserted therein. In this embodiment, the tension jack is placed. It is composed of a portion 46a, a main body portion 46c in which a connecting member 42 is arranged, and a raised portion 46e. The mounting portion 46a is a disk-shaped member provided with an insertion hole 46b through which the tension bar 40 is inserted at the center. The main body portion 46c is a cylindrical member in which window portions 46d are provided at two locations, and two rotation stoppers 48 are provided therein. The raising portion 46e is equivalent to the raising member 52 (see FIGS. 15A and 15B) described later, and in this embodiment, the raising portion 46e has a C shape in a plan view and is spaced apart from the outer peripheral portion. Two ring portions 50 are provided.

The height position of the chair member 46 having the above configuration is adjusted by the raising members 52 and 54 described later so that the connecting member 42 is arranged inside the main body portion 46c. More specifically, as virtually shown in FIG. 14A, two rotation stoppers 48 provided inside the main body portion 46c abut against the width across flats of the hexagonal column portion 42a of the connecting member 42. Is adjusted so that. As a result, the connecting member 42 is constrained in the rotation direction. 14 (a) is a cross-sectional image view of the chair member 46 cut at a height crossing the window portion 46d and shown from the mounting portion 46a side, and FIG. 14 (b) is A in FIG. 14 (a). The arrow view and FIG. 14 (c) are views taken along the arrow B in FIG. 14 (a), and in FIGS. 14 (b) and 14 (c), the ring portion 50 is not shown.

As described above, the raising member 52 shown in FIGS. 15A and 15B includes the bearing plate 86 and the chair member 46 so as to be arranged at a height at which the chair member 46 is located around the connecting member 42. It is installed between. The raising member 52 has an annular shape in a plan view, and is provided with a notch so as to avoid an operating region of the rotational movement of the wrench 12. In this embodiment, the raising member 52 has a C shape in a plan view. .. More specifically, the raising member 52 is composed of two plate-shaped members 52a and 52b having a C-shape in a plan view, which are connected to each other via an outer frame portion 52c and a plurality of radiation portions 52d. The reinforcing material 52e is arranged in the gap between the adjacent radiation portions 52d. Further, the raising member 52 is provided with two ring portions 56 at intervals on the outer peripheral portion. On the other hand, the raising member 54 shown in FIGS. 15C and 15D is different only in thickness from the raising member 52, and its use and structure are the same as those of the raising member 52. Note that in FIGS. 15 (b) and 15 (d), the ring portion 56 is not shown.

Further, as will be described in detail later, the unloading device 10'according to the second embodiment of the present invention is long while being mounted on the chair member 46 via the tension bar 40 and the connecting member 42. It includes a tension jack 60 (see FIGS. 20 to 22) for pulling the construction long member 80 with a load equal to or less than the allowable tensile force of the construction member 80. A so-called center hole jack is used as the tension jack 60 in this embodiment, and is operated by the hydraulic pressure of the hydraulic pump.
The ring portion 50 provided on the chair member 46 and the ring portion 56 provided on the raising members 52 and 54 are shown after the chair member 46 and the raising members 52 and 54 are installed. No pole member is inserted.

Subsequently, with reference to FIGS. 16 to 22, the procedure for installing the unloading device 10 ′ according to the second embodiment of the present invention and the unloading method using the unloading device 10 ′ will be described. In addition, in FIGS. 16 to 22, the long construction member 80 and the unloading device 10'are shown from the plane direction and the front direction, and the planes (a) and (b) in each view have the same timing. It is the figure of the direction and the front direction, and (c) and (d) are the figure of the plane direction and the front direction of the same timing.
First, since each procedure shown in FIGS. 16 and 17 is the same procedure as the unloading device 10 according to the first embodiment of the present invention described with reference to FIGS. 5 to 8 (b). The description is omitted.

Next, as shown in FIGS. 18A and 18B, the connecting member 42 is used to connect the screw structure portion 82 in the tension state and the tension bar 40. That is, the screw hole 42d of the connecting member 42 is screwed into the screw structure portion 82, and the screw groove portion 40a of the tension bar 40 is screwed into the screw hole 42c of the connecting member 42. At this time, the nut member 44 is screwed into the screw structure portion 82 at a position where it contacts the lower end of the connecting member 42, and if the nut member 44 has a set screw, the set screw is also tightened. In FIG. 18A, the tension bar 40, the connecting member 42, and the nut member 44 are not shown. Further, in each of FIGS. 18 to 22 shown from the front direction, the rotation jack 14 is not shown.

Further, as shown in FIGS. 18 (c) and 18 (d), the raising members 52 and 54 are installed on the bearing plate 86 in a manner of being arranged around the nut 84. At this time, the notches of the raising members 52 and 54 having a C shape in a plan view are arranged on the rotation jack 14 side (left side in FIG. 18), and all the raising members 52 and 54-2 are arranged. The two ring portions 56 are installed so as to be aligned in a plan view. In this embodiment, one raising member 54 having a large thickness and one raising member 52 having a small thickness are installed on the bearing plate 86, and the number of these members installed is the length of the screw structure portion 82, etc. Adjust as appropriate according to.

Subsequently, as shown in FIGS. 19A and 19B, the engaging portion 12a of the wrench 12 is engaged with the nut 84 of the long construction member 80 in a tense state, and the connection pin 28 is used. The shaft support end 12b of the wrench 12 is pivotally supported by the shaft attachment portion 16a of the rotation jack 14 located closest to the cylinder portion 14a. At this time, it is preferable that the stroke of the rotary jack 14 is most contracted within a range in which the wrench 12 can be engaged with the nut 84 and the wrench 12 can be axially attached to the shaft attachment portion 16a. As a result, the wrench 12 can rotate with respect to the rotation jack 14 with the connection pin 28 as the rotation axis.

After that, as shown in FIGS. 19C and 19D, the chair member 46 is installed on the raising member 52. At this time, the tension bar 40 is inserted into the insertion hole 46b of the chair member 46, and as shown in FIG. 14A, the rotation stopper 48 provided inside the chair member 46 connects the members in the rotation direction. Restrain 42. Further, the position of the two ring portions 50 provided on the raised portion 46e of the chair member 46 is aligned with the positions of the two ring portions 56 of the raised members 52 and 54 in a plan view. Match the installation orientation. Then, in this state, a pole member (not shown) is inserted into the ring portion 56 of the raising members 52 and 54 and the ring portion 50 of the chair member 46 located on the upper side in FIGS. 19A and 19C. Further, the pole member is also inserted into the ring portion 56 of the raising members 52 and 54 and the ring portion 50 of the chair member 46 located on the lower side in FIGS. 19A and 19C.

Next, as shown in FIGS. 20A and 20B, a tension jack 60 is installed on the mounting portion 46a of the chair member 46 in a manner in which the tension bar 40 is inserted inside, and the tension jack 60 is installed. The upper end of the tension bar 40 protruding upward from the above is fixed by the fastening nut 62. By the procedure up to FIGS. 20A and 20B, each component of the unloading device 10'according to the second embodiment of the present invention is assembled. For convenience of explanation, in each of the views shown from the front direction of FIGS. 20 to 22, the tension jack 60 is shown in a cross section passing through the tension bar 40.

Subsequently, as shown in FIGS. 20 (c) and 20 (d), the tension bar 40 connected to the screw structure portion 82 of the long construction member 80 via the connecting member 42 is elongated by the tension jack 60. When the load is equal to or less than the allowable load of the construction member 80, the tension is increased in the upward direction in FIG. 20 (d). The tension by the tension jack 60 is performed by a hydraulic pump (not shown). Due to this tension, the cylinder inside the tension jack 60 is in an extended state. As a result, a tension force equal to or less than the allowable load acts on the long construction member 80 in the direction opposite to the residual tensile force.

Then, as shown in FIGS. 21 (a) and 21 (b), the rotary jack 14 is extended to the maximum stroke by using a hydraulic pump (not shown) while the tension force of the tension jack 60 is still applied. Then, due to the rotation of the rotary jack 14 with respect to the fixing member 18 and the rotation of the wrench 12 with respect to the ram portion 14b of the rotary jack 14, the extension motion of the rotary jack 14 is counterclockwise with respect to the bearing plate 86. Is converted into the rotational motion of. Therefore, the nut 84 with which the wrench 12 is engaged is rotated in the loosening direction with respect to the bearing plate 86. At this time, the nut 84 in the tense state rotates and loosens, so that the long construction member 80 is slightly pulled downward in FIG. 21 (b). It is absorbed by the contraction of the cylinder inside the tension jack 60.
After that, the unloading device 10 according to the first embodiment of the present invention is used for rotation in which the wrench 12 is pivotally supported in the same manner as the procedure described with reference to FIGS. 9 (b) to 10 (b). While sequentially changing the shaft-mounted portion 16 of the jack 14 from the shaft-mounted portion 16a to the shaft-attached portion 16b and from the shaft-attached portion 16b to the shaft-attached portion 16c, the extension movement of the rotating jack 14 is used to bring the jack 14 into a tense state. Rotate a nut 84.

Then, as shown in FIGS. 21 (c) and 21 (d), with the wrench 12 pivotally supported by the shaft attachment portion 16c of the rotary jack 14, the rotary jack 14 is extended to the maximum stroke and then in a tense state. When further rotating the nut 84 in the above, as shown in FIGS. 22 (a) and 22 (b), the connection pin 28 is pulled out from the shaft attachment portion 16c of the rotation jack 14, and the wrench 12 in the shaft attachment portion 16c is used. Release the shaft. Further, the wrench 12 is moved upward in FIG. 22B to move from the state of being engaged with the nut 84 to the periphery of the nut member 44 and / or the circumference of the cylindrical portion 42b of the connecting member 42. At this time, if the screw structure portion 82 is exposed between the nut 84 and the nut member 44 by a thickness equal to or larger than the thickness of the wrench 12, the wrench 12 may be moved around the exposed screw structure portion 82. As a result, the wrench 12 can rotate with the columnar nut member 44, the columnar portion 42b of the connecting member 42, and / or the screw structure portion 82 as the rotation axis. Therefore, the wrench 12 is rotated to move the wrench 12. The wrench 12 is re-engaged with the nut 84 at a rotation position that can be pivotally supported by the shaft attachment portion 16a of the rotation jack 14.
After that, it is shown in FIGS. 20 (c) and 20 (d) to 22 (a) and (b) until the load (residual tensile force) acting on the nut 84 becomes equal to or less than the allowable load of the long construction member 80. The long construction member 80 is unloaded by repeatedly executing the above procedure.

Now, according to the second embodiment of the present invention having the above configuration, it is possible to obtain the following effects. That is, as shown in FIGS. 23 and 24, the unloading device 10'according to the second embodiment of the present invention has a tension jack 60 attached to the screw structure portion 82 of the long construction member 80 in a tension state. It is used when the tension extra length L required for tensioning the long construction member 80 is secured. Therefore, the unloading device 10 ′ includes a tension bar 40, a connecting member 42, a chair member 46, and at least one raising member 52, 54 as shown in FIGS. 11, 12, 14, and 15. It includes a tension jack 60 (see FIGS. 20-22).

The tension bar 40 is connected to the tip of the screw structure portion 82 by the connecting member 42, and the connecting member 42 has a screw hole 42d provided with a screw groove corresponding to the screw groove of the screw structure portion 82 of the long construction member 80. , Has a female screw structure provided on the right side in FIG. 12 (b). Further, as can be confirmed in FIGS. 18 (c), (d) to 20 (a), (b), a cylindrical shape is placed on at least one raising member 52, 54 installed on the bearing plate 86. A chair member 46 and a tension jack 60 are placed on the chair member 46. At this time, the tension bar 40 and the connecting member 42 are inserted into the cylindrical chair member 46, and at least one raising member 52, 54 is a chair member in order to secure an operating space for the connecting member 42. The quantity to be installed is adjusted so that the 46 is arranged at a height located around the connecting member 42. In the examples of FIGS. 18 to 20, a raising member 54 having a relatively large thickness and a raising member 52 having a relatively small thickness are installed one by one.

In such installation state, as shown in FIG. 20 (c), (d) , that the tension bar 40 is tensioned by the tensioning jack 60, via the connecting member 42 and the tension bar 40, the tension A long construction member 80 is strained. Further, since the tension jack 60 is for tensioning the long construction member 80 with a load equal to or less than the allowable load of the long construction member 80, even when the residual tensile force exceeds the allowable load. The long construction member 80 can be tense without any particular problem. Due to the tension of the long construction member 80, the load acting between the nut 84 and the bearing plate 86 is reduced to the difference between the residual tensile force of the long construction member 80 and the load due to the tension of the tension jack 60. Can be done. Therefore, the long construction member 80 is tensioned by the tension jack 60, and the nut 84 of the long construction member 80 is rotated while the load equal to or less than the allowable load by the tension jack 60 is assisted, so that the nut 84 is rotated. It is possible to reduce the wear of the nut 84 and the bearing plate 86 due to the frictional force of the above. As a result, after the long construction member 80 is unloaded, the nut 84 and the bearing plate 86 can be reused in a state where the wear is reduced.

Further, in the unloading device 10 ′ according to the second embodiment of the present invention, as shown in FIG. 15, the raising members 52 and 54 for adjusting the height position of the chair member 46 are annular in a plan view. In addition, a notch is provided so as to avoid the operating region of the rotational movement of the wrench 12. That is, the raising members 52 and 54 have a C shape in the example of FIG. 15 in a plan view, and a space for arranging the screw structure portion 82 and the like is secured inside. As a result, the raising members 52 and 54, which are installed between the bearing plate 86 and the chair member 46 and are arranged around the nut 84 in contact with the bearing plate 86, are confirmed in FIG. 21 and the like. As a result, the reaction force of the tension by the tension jack 60 can be transmitted from the chair member 46 to the bearing plate 86 without hindering the rotational movement of the wrench 12 that rotates the nut 84.

Further, in the unloading device 10'according to the second embodiment of the present invention, in order to connect the tension bar 40, the connecting member 42 attached to the tip of the screw structure portion 82 and the screw structure portion 82 are tension- fixed. A nut member 44 as shown in FIG. 13 is included between the nut 84 and the nut 84. As can be confirmed in FIG. 18B, the nut member 44 is attached at a position where it comes into contact with the end of the connecting member 46 on the nut 84 side, and is a female screw corresponding to the screw structure portion 82 of the long construction member 80. Together with the connecting member 46 having a structure, the connecting member 46 is prevented from coming off from the screw structure portion 82 by the so-called rotation restraining effect of the double nut.

Further, in the unloading device 10 ′ according to the second embodiment of the present invention, as shown in FIG. 14, a rotation stopper 48 for preventing the rotation of the connecting member 42 in a tense state is provided inside the chair member 46. By being provided, the connecting member 42 is restrained in the rotation direction. By restraining the connecting member 42 and the effect of suppressing the rotation of the double nut by the nut member 44, it is possible to prevent the screw structure portion 82 from rotating together with the nut 84. As a result, when the nut 84 is rotated by the wrench 12, the screw structure portion 82 does not rotate together with the nut 84, so that the breakage of the PC steel wire or the like inside the screw structure portion 82 due to the co-rotation can be prevented. Can be done.

Further, in the unloading device 10 ′ according to the second embodiment of the present invention, as shown in FIGS. 14 and 15, the raising members 52 and 54 centered on the positions of the screw structure portion 82 and the tension bar 40. A ring portion 56 is provided on the outer peripheral portion of the chair member 46, and a ring portion 50 is provided on the outer peripheral portion of the raised portion 46e of the chair member 46. A pole member is inserted through the ring portion 56 of the raising members 52 and 54 and the ring portion 50 of the chair member 46. That is, the pole member is inserted through the ring portions 56 and 50 of both the raising members 52 and 54 and the chair member 46, so that the raising members 52 and 54 and the chair member 46 are displaced from each other and the raising member 52 is raised. When a plurality of the raising members 52 and 54 are installed, the displacement between all the raising members 52 and 54 is also prevented. This makes it possible to perform the unloading work while arranging the raising members 52 and 54 and the chair member 46 at appropriate positions.
Then, in the unloading method using the unloading device 10'according to the second embodiment of the present invention, the long construction member 80 is unloaded by the procedure shown in FIGS. 20 to 22. It is possible to obtain the same action and effect as the unloading device 10'according to the second embodiment of the present invention.

Further, in the unloading devices 10 and 10 ′ according to the first and second embodiments of the present invention described above, the long construction member 80 to be unloaded is a ground anchor in a tense state as shown in FIG. 80A, or that it is a civil engineering tie rod 80B which is in tension, as shown in FIG. 24, the ground anchor 80A and civil engineering tie rod 80B which prestressing is applied, while exhibit the various advantageous effects as described above Can be unloaded.
The unloading devices 10 and 10'according to the first and second embodiments of the present invention are used not only for the ground anchor 80A of the "nut fixing method" but also for the ground anchor of the "wedge fixing / nut adjusting method". Is also applicable. In this case, an appropriate rotating means corresponding to the above-mentioned wrench 12 capable of rotating the nut used for the adjustment with the ground anchor of the "wedge fixing / nut adjusting method" may be used.

10, 10': Unloading device, 12: Wrench, 14: Rotating jack, 16: Shaft attachment part, 18: Fixing member, 40: Tension bar, 42: Connecting member, 44: Nut member, 46: Chair member, 48: Rotation stop, 50: Ring part of chair member, 52, 54: Raising member, 56: Ring part of raising member, 60: Tension jack, 80: Long construction member, 80A: Ground anchor, 80B: Tie rod for civil engineering , 82: Screw structure, 84: Nut, 86: Support plate

Claims (10)

A length having a screw structure at at least one end, which is used to apply prestress to the construction position by tension and is fixed to the surface of the construction position in a tensioned state using a nut via a bearing plate. It is a unloading device for shaku construction members.
A wrench for rotating the nut in a tense state,
A rotary jack having a shaft-attached portion whose end portion of the wrench opposite to the side engaged with the nut is detachably supported by a shaft.
The stretching movement of該回diverted jack to be converted into rotational movement of the wrench, seen including a fixing member for fixing the rotary jack to the bearing capacity plate,
The rotary jack is a unloading device characterized in that a plurality of shaft-attached portions are linearly arranged in the expansion / contraction direction of the rotary jack at an arrangement interval within the stroke range of the rotary jack. A length having a screw structure at at least one end, which is used to apply prestress to the construction position by tension and is fixed to the surface of the construction position in a tensioned state using a nut via a bearing plate. It is a unloading device for shaku construction members.
A wrench for rotating the nut in a tense state,
A rotary jack having a shaft-attached portion whose end portion of the wrench opposite to the side engaged with the nut is detachably supported by a shaft.
Includes a fixing member for fixing the rotary jack to the pressure plate so that the expansion and contraction motion of the rotary jack can be converted into the rotary motion of the wrench.
Tension bar and
A connecting member that connects the tension bar and the screw structure portion of the long construction member, and
A tension jack for pulling the construction long member with a load equal to or less than the allowable load of the long construction member through the tension bar and the connecting member.
With the tension bar and the connecting member inserted inside, the cylindrical chair member on which the tension jack is placed and the chair member
As the chair member is disposed at a height position around the coupling member, characterized in that it comprises, at least one raising member is installed between the chair member and the bearing capacity plate unloading equipment. The rotary jack is the arrangement interval in the range of the stroke of該回diversion jack, according to claim 2, wherein said shaft wear part is characterized in that it is more linearly arranged to expansion and contraction direction of the rotary jack Unloading device. 2. Loading device. The screw structure includes a nut member attached between the nut and the connecting member at a position where the connecting member comes into contact with the end of the connecting member on the nut side.
The unloading device according to any one of claims 2 to 4, wherein a rotation stopper for preventing rotation of the connecting member is provided inside the chair member. A ring portion is provided on each of the outer peripheral portion of the at least one raising member and the outer peripheral portion of the chair member centered on the positions of the screw structure portion and the tension bar, and the at least one raising member is provided with a ring portion. The unloading device according to any one of claims 2 to 5, wherein a pole member is inserted through the ring portion and the ring portion of the chair member. The unloading device according to any one of claims 1 to 6, wherein the long construction member is a ground anchor in a tense state or a tie rod in a tense state. A length having a screw structure at at least one end, which is used to apply prestress to the construction position by tension and is fixed to the surface of the construction position in a tensioned state using a nut via a bearing plate. It is a method of unloading the shaku construction member.
The wrench is engaged with the nut, and the end of the wrench on the side opposite to the side that engages with the nut can be attached to and detached from the shaft attachment portion of the rotary jack fixed to the bearing plate via the fixing member. The nut is pivotally supported, and the expansion and contraction of the rotation jack is used to apply a rotational force to the nut via the wrench using the pressure plate as a reaction force to rotate the nut in a tense state in a loosening direction. ,
At this time, as the rotation jack, a plurality of shaft-attached portions are arranged linearly in the expansion / contraction direction of the rotation jack at an arrangement interval within the stroke range of the rotation jack. A unloading method, characterized in that the nut is rotated while sequentially changing the shaft-attached portion that pivotally supports the end portion of the wrench to the extension direction side of the rotating jack. A tension jack is attached to at least one end of the long construction member, and tension is applied in the direction of pulling the long construction member by the tension jack while applying a load equal to or less than the allowable load of the long construction member. The unloading method according to claim 8, wherein the nut in a state is rotated. The unloading method according to claim 8 or 9, wherein the long construction member is a ground anchor in a tense state or a tie rod in a tense state.

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