JP3495720B2 - PC structure in which concrete members with different construction periods are integrated and its construction method - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a prestressed concrete structure. More specifically, the present invention relates to a prestressed concrete structure (PC structure) in which a concrete member additionally added to an existing concrete member is integrated with a PC steel material, and a construction method thereof.

[0002]

2. Description of the Related Art Conventionally, for example, in the case of constructing adjacent viaducts of upper and lower lines by using movable supports, after passing through the movable supports on the widthwise end side of each viaduct, For the reinforcement and expansion of concrete members such as the construction of post-casting floor slabs, after a certain period of time has passed after the construction of the concrete members that were previously constructed, additional concrete members must be additionally constructed and integrated. Often it does not happen. Conventionally, in such a case, the following two construction methods A and B have been used.

A (first conventional example): Before placing concrete on a concrete member to be constructed first, a reinforcing bar is placed at a predetermined position in advance, and the reinforcing bar is placed on the side where new concrete is to be placed. Extend the length of the lap length. Then, after a predetermined period of time,
Reinforcing bars arranged in the additional part are arranged so as to be wrapped, and the concrete in the additional part is placed to integrate both concretes. Since this construction method is the most general method, illustration is omitted.

B (second conventional example): FIGS. 12 (a) and 12 (b)
As shown in (1), before placing concrete on the concrete member 30 to be constructed first, the PC steel rod 32 and the fixing tool 33 housed in the sheath 31 in advance are arranged at predetermined positions, and the concrete is placed. Then, after the concrete exhibits a predetermined strength, the PC steel rod 32 is tensioned by a tensioning device such as a tensioning hydraulic jack, a tensioning manual pump, or the like so that the PC steel rod 32 is brought into contact with the outer surface of the concrete member 30.
The pressure bearing plate (later the anchor plate 3
38a is used for fitting and mounting, and a nut 39 is screwed and fixed to fix (after the temporary tension fixing work), the tension device is released , and the concrete member 30 is released.
Pre-stress.

Next, prior to placing the concrete 34a of the additional concrete member 34, the existing concrete member 3
0, the PC steel rod 32 arranged inside the additional concrete member 34, and the PC steel rod 36 arranged inside the sheath 35, which is accommodated in the sheath 35 in advance, are screwed in advance by the coupler 37. Concrete 34a is placed. Then, after the placed concrete 34a exhibits a predetermined strength, the PC steel rod 36 arranged in the additional concrete member 34 is similarly tensioned by a tensioning device such as a tensioning hydraulic jack 40 or a manual tensioning pump. Then, the anchor plate 38 and the nut 39 are attached and fixed, and a pre-stress of approximately the same amount as the pre-stress given to the existing concrete member 30 is applied to the additional concrete member 34, so that both concrete members 30, 34 are attached. Unify.
In this case, grout mortar is injected into the gap between the PC steel rods 32 and 36 and the sheaths 31 and 35 so that the PC steel rods 32 and 3 are
It is obligatory to perform rust prevention as described in item 6.

[0006]

In the case of the above method A, a reinforced concrete structure (RC structure) is adopted, which is adopted for a member having a relatively small member and a small bending moment. When the overhang span is large, the diameter of the reinforcing bar is large and the amount of reinforcing bar is large, which deteriorates the workability. Moreover, since it is a reinforced concrete structure, there is a problem that cracks cannot be avoided.

In the case of the method B, a PC structure is used. (1) It is adopted when the bending moment is large, but a sheath work and a grout work are required, and (2)
Performing the tensioning work of the PC steel rods 32 and 36 in two times, respectively. (3) When the PC steel rods 32 and 36 are tensioned and fixed, the prestress is reduced due to the set loss, and the short PC steel rods. In the case of, it is difficult to manage the tension with high accuracy, (4) When tensioning the PC steel rod 32 arranged on the concrete member 30 that was initially constructed,
When temporarily tensioning the PC steel rod 36 arranged on the additional concrete member 34, the anchor plate 38, the nut 39,
There was a problem that the washer 41 and the like were required, and the construction cost was increased.

Therefore, in the present invention, when introducing prestress, there is no reduction in prestress due to set loss, the construction process is shortened, the construction cost is reduced, and even if a larger sectional force acts, An object of the present invention is to provide a PC structure capable of firmly integrating concrete members that have been constructed at different times by introducing prestress without causing cracks in the concrete members, and a construction method thereof.

[0009]

In order to solve the above problems, in the integrated PC structure of the existing side concrete member and the additional side concrete member of the first invention, one side end portion provided with a pressure bearing member is already installed. The existing side hollow PC steel material that is fixed in the concrete member and the other side end portion is extended to the additional concrete member side, and the one end portion is joined to the extending end of the hollow PC steel material through a joint tool. And the additional side hollow PC steel material in which the other side end is extended and arranged outside the additional concrete member while penetrating the additional concrete member, and is inserted into both of the hollow PC steel materials over substantially the entire length thereof. A hollow PC having a solid PC steel material arranged therein,
In the state where tension is applied to the steel material, the additional concrete member in which concrete is placed and hardened is provided on the additional side, and the tension of the hollow PC steel rod is released to introduce prestress to both concrete members. It is characterized in that both concrete members are integrated.

In the construction method of the PC structure for integrating the concrete members of different construction times of the second invention,
One end with the pressure bearing member is fixed in the existing concrete member, and the other end is extended to the extension concrete member side. The expansion side hollow PC steel materials are joined via the above, then a solid PC steel rod is inserted into both hollow PC steel materials, and then the solid PC steel material is applied to the expansion side hollow PC steel materials as a reaction force. By placing the concrete in order to build an additional concrete member in a state where tension is applied to both hollow PC steel materials in advance by pushing in and hardening, then the tension of the hollow PC steel rod is released. The feature is that prestressing is introduced into both concrete members to integrate both concrete members.

In a third invention, in the second invention,
Means or tension for applying tension to the hollow PC steel bar
The releasing means includes an engaging portion that engages with the different diameter sleeve screwed to the end of the hollow PC steel rod to take a reaction force, and is also screwed with the different diameter sleeve. Stop
It is a tensioning and releasing device provided with an electric torque wrench provided with a turning engaging portion that engages with the clutch .

In a fourth invention, in the third invention,
The tension applying and releasing apparatus, the when and a reaction force engaging portion which is to take engage reaction force to a different size sleeve co
To the stopper engaged with the different diameter sleeve.
It is a tensioning and releasing device including a gearbox having a dynamic engaging portion and an electric torque wrench connected to the gearbox via a power booster.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2
FIG. 3 is a vertical sectional front view showing a case where the present invention is applied to a concrete floor slab of a PC bridge in which an up lane (PC girder) and a down lane (PC girder) of a high-speed elevated road are constructed in parallel. Figure 3
FIG. 4 is a diagram showing a disposition state of PC steel material, and FIG. 4 is a configuration diagram of PC steel material. FIG. 5 is an explanatory view showing a tension applying / releasing device including an electric torque wrench device for releasing the tension force of the PC steel material. And FIG. 6 is an explanatory view showing a construction procedure.

First, as shown in FIG. 1, a PC (prestressed concrete) girder on the up lane 2 side and a PC girder on the down lane 3 side of an elevated road, which are juxtaposed in parallel with each other, are connected to one lane (one PC In the case of the PC bridge 1 constructed by the erection work vehicle 4 which is a moving support work, the two lanes (PC
Since the gap between the floor girders 2 and 3 of the girders 2 and 3 is set to about 2 cm, the lane (PC girder) 2 on the side to be constructed later can be moved by the erection work vehicle 4 during construction. After providing the splicing portion 5 (see FIG. 3) on the floor slab portion 2a projecting to the side of the down lane (PC girder) 3 and temporarily expanding the gap, the existing concrete member 6 develops a predetermined strength. ,
In addition, after the erection work vehicle 4 has passed, an additional concrete member 7 which projects from the rear toward the down lane (PC girder) 3 side from the splicing section 5 must be post-cast (two-dot chain line in FIG. 2). Circled part).

During such a two-stage construction in the width direction of the floor slab, the prestressed concrete structure of the present invention (hereinafter,
PC structure) is applied to the existing concrete member 6 that is the floor slab on the base end side that was constructed in advance, and the additional concrete member 7 for post-casting that is the floor slab of the tip connected to this is applied. Lanes (PC girders) that were integrated afterwards and constructed later
The strength of the entire floor slab that is double-strike construction is the same as that when the entire floor slab is constructed at once.

As shown in FIG. 3, the PC steel material 8 constituting the PC structure is arranged over the existing concrete member 6 and the additional concrete member 7, and is constructed as shown in FIG. That is, the anchor plate 9 with the female screw hole that acts as a bearing member is provided at a predetermined position near the end in the width direction of the base side slab of the existing concrete member 6 that is the base side slab to be constructed in advance. A short end holder 10 made of a full screw thread is screwed to the female screw hole of the anchor plate 9. And
An internal thread portion of a base end portion (one side end portion) of an existing side hollow PC steel rod (existing side hollow PC steel material) 11 is screwed to the end holder 10. In this way, the existing side hollow P of a predetermined length
The base end of the C steel rod 11 is closed.

The existing side hollow PC steel rod 11 having a predetermined length.
Is disposed at a predetermined position so as to extend in the width direction of the floor slab at the end of the base end side floor slab, and the distal end (the other end) of the hollow PC steel rod 11 is an existing concrete member. 6
The splicing portion 5 (end portion), that is, the end portion of the existing concrete member 6 is disposed so as to extend outward (project). In addition, many hollow PC steel materials 8 are in the lane (PC girder)
3, that is, in parallel with each other at predetermined intervals in the direction of extension of the longitudinal direction of the road, the anchor plates 9 are arranged in a staggered pattern in a plan view, and are supported by a large number of anchor plates 9. Make sure that the pressure surfaces are not in the same vertical plane.

At the tip (exposed end) of each existing side hollow PC steel rod 11, a male screw portion 11a is provided on the outer peripheral surface,
One end side of a coupler (joint tool) 13 made of a cylindrical female screw is screw-joined to the male screw portion 11a, and the coupler 13
On the other end side of the, the expansion side hollow PC steel rod 12 (expansion side hollow PC steel material) of the expansion concrete member 7 side that is post-cast
The male screw portion 12a on the outer peripheral surface of the base end portion is screwed and integrated in series. At the time of this screw joining, the existing concrete member 6 that has been constructed in advance develops a predetermined strength.

Then, a male screw portion 12b on the outer peripheral surface of the end of the extension side hollow PC steel rod 12 extending to the notch 14 on the end side in the width direction of the floor slab in the extension concrete member 7.
An anchor nut 15 is screwed in, and an inner female screw portion 16a of a hollow hexagonal column-shaped different-diameter sleeve 16 which is a holder of the stopper 19 is screwed in adjacent to the outer side of the anchor nut 15. The different-diameter sleeve 16 is disposed so as to be exposed in the cutout portion 14 of the additional concrete member 7.

A solid reaction PC steel rod (solid PC steel material) 17 is inserted into each of the hollow PC steel rods 11 and 12, and its tip is in contact with the end holder 10 to indirectly. It is in contact with the anchor plate 9. On the other hand, the mouth end (right end) of the solid reaction PC steel rod 17 is stepped with a small-diameter shaft portion arranged in the different-diameter sleeve 16 and a large-diameter shaft portion integrally connected to the small-diameter shaft portion. It is in contact with an inner end (left end) of a stopper 19 formed of a hollow male screw bolt screwed into a female screw hole at an outer end of the different-diameter sleeve 16 via a columnar pushing piece (pushing member) 18.

Thus, the reaction force PC steel rod 17 can be sandwiched between the anchor plate 9 at the base portion on the existing side hollow PC steel rod 11 side and the stopper 19 without any gap. The outer end (right end) of the stopper 19
A hexagonal head portion 19a serving as a rotary tool engaging portion is formed on the. The outer diameter dimension of the hexagonal head portion 19a viewed from the axial direction is set to be smaller than the outer diameter dimension of the different diameter sleeve 16, and in this embodiment, the head portion 19a has a similar shape to the different diameter sleeve 16. Has been done.

Next, in the case where a tension force is applied to both hollow PC steel rods 11 and 12 before the additional concrete member 7 is built, an electric torque wrench 21 and an electric gear box 23 having a vertical gear box 23 are used. By using the structure of the tensioning and releasing device 29 composed of the luc wrench device 20 and the electric torque wrench device 20, the hollow PC steel rods 11,
A procedure for introducing a tension force into the armature 12 will be described in detail with reference to FIGS.

First, the structure of the tensioning and releasing device 29 including the electric torque wrench device 20 will be mainly described with reference to FIG.
The output shaft 21a of the electric torque wrench 21 is an input of the power booster 22 in a gear box 23 having a speed reducer 22 having a gear reduction type or a speed reduction mechanism such as a worm and a worm wheel or a torque converter. It is engaged with the shaft 22a. In the gear box 23, a spur gear 25 having an angular shaft engaging hole 25a engaged with an angular shaft portion 22c at the tip of the output shaft 22b of the booster 22 and a plurality of small diameter spur gears 2 meshing with the spur gear 25.
4a, a large-diameter intermediate spur gear 24b that meshes with the small-diameter spur gear 24a, a plurality of small-diameter intermediate spur gears 24c that mesh with the large-diameter intermediate spur gear 24b, and the small-diameter intermediate spur gear 24c.
The output gear 26, which is a large-diameter spur gear on the output side that meshes with, is sequentially arranged toward the output side, and is rotatably supported by the gear box 23 by the horizontal shaft.

Further, the output gear 26 is provided with a rotation engaging portion 26 including a hexagonal recess (a through hole in the case shown) for fitting with the hexagonal head portion 19a of the stopper 19.
a is provided. Therefore, the electric torque wrench 2
The output shaft 21a of No. 1 is interlocked with the output gear 26 via the gear mechanism in the gear box 23, whereby the stopper 19
The hexagonal head portion 19a in is driven to rotate. By driving the electric torque wrench 21 to rotate the stopper 19 in the forward direction, the stopper 19 is moved so as to be screwed toward the inside of the different-diameter sleeve 16, whereby the reaction force PC steel rod is pushed through the pushing piece 18. As 17 is pushed in, a tension force is relatively introduced to the hollow PC steel rod 12 arranged on the outside. The state in which this tensioning force is introduced in a state of being held by the stopper 19, and moves the tension imparted and release device 29 having an electric torque wrench in the axial direction of the hollow PC steel rod 12, temporarily tensions imparted cum Remove the release device 29. The reinforcing bars and the formwork are arranged at appropriate times.

Next, with this balanced state maintained, around the hollow PC steel rod 12 on the expansion side,
Further, the additional concrete member 7 is constructed by pouring the additional concrete so as to be continuously connected to the existing concrete member 6.

After the concrete cast around the hollow PC steel rod 12 has hardened, the tensioning / releasing device 29 is mounted again to move the electric torque wrench 21 in the rotating direction. Is driven in the opposite direction and the stopper 19 is rotated in the reverse direction to release the tension state of the hollow PC steel rod 12, and the existing concrete member 6 and the additional concrete member 7 are compressed (prestressed). ) Is introduced, the existing concrete member 6 and the additional concrete member 7 can be firmly integrated.

When the hollow PC steel rod is tensioned or released, it is necessary to take a reaction force when the stopper 19 is normally or reversely rotated. In this embodiment, the housing 23a of the gear box 23 is used.
On the side, the sleeve 16 of different diameter is concentric with the output gear 26.
Is provided with a reaction force engagement hole 26b composed of a hexagonal recess or the like having a size slightly larger than the different-diameter sleeve 16 for fitting to the non-circular outer surface (outer surface of hexagonal cross section in the figure). ing. The reaction force engagement hole 26b is provided in the stopper 19
It is also an insertion hole for the hexagonal head portion 19a. Therefore, the gear box 23 (or the tensioning and releasing device 2
9) does not rotate relatively. In this embodiment, reaction force engagement holes 26b are provided on both front and back sides of the gear box 23 so as to be concentric with the rotation engagement portion 26a and to have the same center line.

Small diameter spur gear 24 in the gear box 23
The a and 24c and the intermediate large-diameter spur gear 24b serve as an odd number of transmission mechanisms from the input gear 25 to the output gear 26 together with the torque transmission, so that the rotation directions of the input side gear and the output side gear are the same. , The rotational direction is aligned and the arrangement space can be saved.

By the rotation of the output gear 26 in the loosening direction, the stopper 19 moves toward the loosening side in the different-diameter sleeve 16 (to the right, that is, the stopper 19 moves away from the expansion side hollow PC steel rod 12). Moved to the push piece 1
8 becomes free. By this, solid reaction force PC
The steel rod 17 is released from the compressive force.

In the case described above, the vertical gear box 23 is used, but the gear box 23 provided with a gear mechanism is omitted, and as shown in FIG. Chair for reaction force provided with a non-circular engaging portion formed of a non-circular engaging hole 56 (a hexagonal engaging hole in the figure) that engages with the non-circular outer surface (hexagonal outer surface in the figure) of The base end side of the (case) 57 is fitted and fixed to the non-circular outer surface of the power booster 22, and the inside of the reaction force chair 57 is engaged with the output shaft of the power booster 22 and 6 of the stopper 19 is provided. Tensioning and solution constituted by mounting a steel socket 58 having a rotation engaging portion that engages the square head 19a
Be used release device 29a, similarly to the tension applied and released <br/> apparatus 29 of the embodiment, it is possible to tension and release operations. For this tension applying and releasing device 29a, can be effectively used when the adjacent deck 3a is construction such that a relatively close proximity to the expansion concrete member 7, tension applied and the embodiment In the case of the releasing device 29, even if the floor slab 3a adjacent to and adjacent to the extension side concrete member 7 is built, the extension concrete member 7
To, by forming a cut-out portion 14, easily tension grant
By arranging the vertical gear case 23 in the combined release device 29, the tension releasing work of the hollow PC steel rods 11 and 12 can be easily performed.

More detailed description will be made on the case where the tensioning and releasing device 29 composed of the electric torque wrench device 23 is used to introduce tension to the existing hollow PC steel rod 11 and the additional hollow PC steel rod 12. To explain, from the end side of the state diagram of FIG. 6c, the reaction force engagement hole 26a in the vertical gear box 23 is engaged with the end portion of the different diameter sleeve 16 on the end side of the expansion side hollow PC steel rod. The hexagonal head 19a of the stopper 19 is fitted in the hexagonal hole for output of the output gear 26.

In this state, the electric torque wrench 21 is driven to rotate the stopper 19 so as to further screw it into the different diameter sleeve 16 (to move it forward), and the reaction force PC steel rod 17 is inserted through the pushing piece 18. Push in.

At this time, since there is no protrusion on the outer peripheral surface on the proximal end side of the existing hollow PC steel rod 11 which is relatively tensioned, when the existing hollow PC steel rod 11 extends a little, the existing hollow PC steel rod outer peripheral surface and existing side floor slab concrete 6a
The adhesion with the above is easily released, and the compression force applied to the inner portions of the end holder 10 and the reaction PC steel rod 17 in the anchor plate 9 and the pushing piece 18 and the stopper 19 and the hollow PC steel rods 11 are provided. , 12, the anchor plate 9, the anchor nut 15, and the tensile force acting on the outer portion of the different-diameter sleeve 16 and the like progress while balancing. Therefore, the tensile force or the compressive force is not acting on the existing side slab concrete 6 at this time.

In this way, the reaction force PC steel rod 17 in the hollow PC steel rods 11 and 12 is pushed through the stopper 19 and the reaction force PC steel rod 17 is engaged with the pushing piece 18 for fishing. To match. Since the tensioning / releasing device 29 can be removed in such a balanced state, the tensioning / releasing device 29 is retracted to remove the tensioning / releasing device 29. In this way, the tension force (pre-tension) is introduced into the PC steel material 8 composed of all the hollow PC steel rods 11 and 12 in the predetermined section.

From this state, as shown by the two-dot chain line in FIG. 3 and by the solid line in FIG. 6d, the concrete member 7 on the extension side is constructed so as to embed the anchor nut 15 (the floor slab rebar and the formwork). Etc. are omitted), and the concrete member 7 on the extension side is hardened.

The notch 14 at the widthwise end of the additional floor slab of the additional concrete member 7 is mainly used to apply tension and to release the tension.
It is a working space in which the release device 29 is arranged and tensioned or released via the stopper 19.

Next, after the concrete member 7 on the additional side is hardened, the tension of the hollow PC steel rods 11 and 12 extending over the concrete member 6 on the existing side and the concrete member 7 on the additional side is released, and the concrete on the existing side is released. Compressive force (prestress) across the member 6 and the concrete member 7 on the extension side
In the case of introducing the above, the tensioning and releasing device 29 including the electric torque wrench device 20 is mounted as shown in FIG.
a is driven to rotate in the reverse direction, the stopper 19 is rotated in the reverse direction, and the stopper 19 is moved backward to move the reaction force PC steel bar 17
Releasing the compressive force applied to the concrete and introducing the compressive force into the concrete through the hollow PC steel rod 12 in the portion relatively attached to the concrete and the anchor nut 15 screwed to the hollow PC steel rod 12. You can

Next, before constructing the additional concrete member 7, using a tensioning and releasing device 29 other than the above,
Since it is also possible to impart tension to both hollow PC steel bars 11 and 12, for this case, tension applied and the known hollow PC steel rod is also shown in Japanese Patent No. 2678158
The structure of the release device 29 and the procedure for using this device 29 to introduce tension in a hollow PC steel rod will be briefly described with reference to FIG.

The structure of the tensioning and releasing device 29 for the PC steel rod will be briefly described. The center hole jack 42
A rear frame 43 having a hole and a reaction force supporting front frame 45 having a hollow PC steel rod insertion through hole 44 are arranged at intervals and are connected by a connecting rod 46 to form a frame frame 47 with a jack. And the center axis of the center hole jack 42 and the center axis of the hollow PC steel rod insertion through hole 44 are arranged on the same center axis, and the hollow piston rod 49 of the center hole jack 42 is screwed. 50 is screwed so as to be movable in the front-rear direction (width direction of the floor slab), and at the rear end of the screw rod 50,
A front end portion of a screw rod rotation drive shaft 52 having a rotation lever 51 is engaged, a rear end portion of a pushing relay rod 55 is locked to a front end portion of the screw rod 50, and the hollow PC steel rod insertion through hole is formed. 44 and a front frame 45 for supporting the reaction force
A split annular support member 48 is provided which is engaged with the rear surface of the rear portion.

When the tensioning / releasing device 29 for the PC steel rod is used to introduce tension to the existing hollow PC steel rod 11 and the additional hollow PC steel rod 12, the state of FIG. 6c is obtained. from the end portion side of the figure, the tension applied and released instrumentation to tension imparted and release device an end portion side of the extension side hollow PC steel rod sequentially hollow PC steel rod insertion hole 44 in the 29 insertion of PC steel bar With the arrangement 29 arranged and the anchor nut 15 separated from the rear surface of the reaction force supporting front frame 45, the split type pressure supporting member 48 is inserted into the hollow PC steel rod insertion through hole 44. While engaging with the rear surface of the front frame 45, the anchor nut 15 is engaged with the rear surface of the bearing member 48. Then, the turning lever 51 is rotated to engage the pushing relay rod 55 with the pushing piece 18 and the screw rod 50.

In this state, the center hole jack 42 is operated so as to extend. At this time, since there is no projection on the outer peripheral surface of the existing hollow PC steel rod 11, the outer peripheral surface of the existing hollow PC steel rod and the existing floor slab concrete are easily released from each other, and PC steel rod 11,1
2 and anchor plate 9 and anchor nut 15
Etc., the outside portion of the anchor plate 9, the end holder 10 in the anchor plate 9, the reaction force PC steel rod 17, and the pushing piece 1.
8 and the inner part of the relay rod 55 etc. also serves to add tension.
Similar to the above-mentioned case, the releasing device 29 is engaged with the frame 47 side and the screw rod 50, and the compressive force acting on the inner portion progresses while being balanced by the tensile force acting on the outer portion. Further, the same applies to the existing side slab concrete 6 in that no tensile force or compressive force is acting at this point.

In this way, the reaction force PC steel rod 17 in the hollow PC steel rods 11 and 12 is pushed through the relay rod 55, and then the different diameter sleeve 16 which is free.
Alternatively, the stopper 19 is rotated to push the reaction force PC steel rod 17 into sufficient engagement with the piece 18 for balancing. In this state, the tensioning and releasing device 29 for the PC steel rod can be removed, so that the hollow piston rod 49 is retracted, and the turning lever 51 is rotated as necessary to rotate the screw rod 50.
When the tensioning / releasing device 29 is moved forward toward the existing side floor slab 2a.
Since there is an axial movement space in which 8 can be removed, this is removed, and then the tensioning and releasing device 29 is moved backward,
The different diameter sleeve 16 is passed through the hollow PC steel rod insertion through hole 44, and the tension applying and releasing device 29 is removed. In this way, all the hollow PC steel bars 11, 1 in the predetermined section are
It is also possible to introduce a tension force (pretension) into the PC steel material 8 made of 2.

From this state, as shown by the two-dot chain line in FIG. 3 and the solid line in FIG. 6d, the concrete member 7 on the extension side is constructed in the same manner as described above so that the anchor nut 15 is embedded, and the extension is performed. The side concrete member 7 is hardened.

After the concrete member 7 on the expansion side is hardened, the tension of the hollow PC steel rods 11 and 12 extending over the concrete member 6 on the existing side and the concrete member 7 on the expansion side is applied.
When releasing and introducing a compressive force (prestress) between the existing side concrete member 6 and the extension side concrete member 7, the tension applying and releasing device 29 is used as a releasing device. Use, attach by the reverse procedure of the above removal procedure, operate the center hole jack 42,
It can be released by freeing the different-diameter sleeve 16 or the stopper 19, but when the floor slab on the side of the adjacent road bridge is built and the required work space cannot be secured, the above vertical type is used. by placing the gear box 23, the solution
Just let it go.

Next, the construction procedure and operation of the PC concrete structure will be further described with reference to FIG.

First, as shown in FIG. 6 (a), the anchor plate 9 (root portion) of the existing hollow PC steel rod 11 is arranged at a predetermined position of the existing concrete member 6 to be constructed in advance, and the splicing portion is formed. The existing side hollow PC extending from 5
The coupler 13 is screw-joined to the threaded portion of the steel rod 11, and the existing concrete member 6 that has been previously constructed is placed.

Then, after a predetermined strength is developed, FIG.
As shown in (b), the expansion side hollow PC steel rod 12 is screwed to the outer half portion of the coupler 13 to form the double hollow PC steel rod 1
1 and 12 are integrated.

Next, as shown in FIG. 6 (c), a solid reaction PC steel bar 17 is placed inside both hollow PC steel bars 11 and 12.
Then, the peripheral clearance between the hollow PC steel rods 11 and 12 is filled with a slow-curing synthetic resin 27 for adhesion and rust prevention (see FIGS. 3 and 4). In addition, before connecting the expansion side hollow PC steel bar 12 by screw, the reaction force PC steel bar 17 is inserted,
Synthetic resin 27 is temporarily placed in the circumferential gap with the existing hollow PC steel rod 11.
May be filled. Further, the solid reaction force PC steel rod 27 is divided into two as shown by the chain double-dashed line B in FIG. 4b, and is connected in series in the existing hollow PC steel rod 11 and the extension side reaction force PC steel rod 12, respectively. It is also possible to arrange it in the.

Then, the anchor nut 15 is screwed into the expanded side hollow PC steel rod 12 and is arranged so as to face the notch portion 14. Further, the different diameter sleeve 16 is screwed into the expansion side hollow PC steel rod 12 extending to the notch portion 14. Also,
The push piece 18 is inserted into the mouth end of the different diameter sleeve 16, and the stopper 19 is screwed in. The expansion side hollow PC steel rod 12 to which the anchor nut 15, the different diameter sleeve 16 and the stopper 19 are attached may be attached to the existing side hollow PC steel rod 11.

Then, the above-mentioned tension is attached to the notch portion 14 .
Tensioning and releasing device 29 is set by setting the giving and releasing device 29
The solid reaction force PC steel rod 17 is pushed in via the pushing piece 18 and compressed while the reaction force of 1 is applied to the different diameter sleeve 16 or the anchor nut 15.

Then, as described above, the reaction force P is maintained while maintaining the balance between the compression force and the tension force in the inner portion and the outer portion.
By compressing the C steel rod 17, both hollow PC steel rods 11 and 12 are stretched to give a tension force.

As a result, the existing hollow PC steel rod 11 arranged in the existing concrete member 6 which was previously constructed is
When it is expanded, the existing concrete 6a and the outer peripheral surface of the existing hollow PC steel rod 11 are cut off ( released ) and can be further expanded, and the balance between the inner part and the outer part is maintained. At this point, the existing hollow PC steel rod 11 is merely pulled out without exerting a supporting pressure on the anchor plate 9, and the existing hollow PC steel rod 11 can be given a tension force. It is possible.

Further, since the outer peripheral surface of the existing hollow PC steel rod 11 embedded in the existing concrete member 6 is not provided with a protrusion, the concrete of the existing concrete member 6 and the existing hollow PC steel rod 11 can be easily assembled. The cracks due to tensile stress are prevented from occurring in the concrete due to the breakage of the adherence to the concrete. Next, the additional fill member 7 is embedded so that the anchor nut 15 is embedded.
Pour concrete.

[0054] After the expansion concrete member 7 expressed the predetermined intensity, as shown in FIG. 9, tension applied as the preferred embodiment which can be installed even in a narrow working space
The electric torque wrench 21 in the combined release device 29 is rotated in the reverse direction, the stopper 19 is rotated in the screw return direction and moved rearward, the compressive force applied to the reaction force PC steel bar 17 is removed, and the relatively outer side. A compressive force is introduced into each hollow PC steel rod 11, 12. At this time, the anchor plate 9 and the anchor nut 15 function as pressure bearing members, and the relatively long threaded portion on the outer peripheral side of the expansion side hollow PC steel rod 12 also enhances adhesion and contributes to the introduction of compressive force of the concrete member 7. is doing.

Thus, as shown in FIG. 6e, prestress is introduced between the existing and expanded concrete members 6 and 7 by the adhesion of the expanded hollow PC steel rod 12 and the expanded concrete to which tension is applied, and both concretes are added. Member 6,
7 is firmly integrated.

Next, the electric torque wrench device 20, the different diameter sleeve 16, the stopper 19, and the pushing piece 18
Remove. Then, finally, the notch 14 is filled with the mortar 28, and the work is completed.

After removing the compressive force applied to the reaction-force PC steel rod 17, the reaction-force PC steel rod 17 is replaced with the hollow PC steel rod 1.
Since it is installed inside 1, 12, synthetic resin 2 filled in the gap
7 hardened over time, and both hollow PC steel bars 11,
12 and the reaction force PC steel rod 17 integrally bear the stress due to the load. In this respect, it is advantageous to use a single reaction force PC steel rod 17.

When a torque wrench device, particularly a tensioning and releasing device which is a combination of a vertical gear box, a booster and an electric torque wrench, is used as shown in the above embodiment,
Even when adjacent viaducts of upper and lower lines are built close to each other, the tensioning work and the releasing work of the hollow PC steel rod can be easily performed easily.

In the case of the above embodiment, since the slow hardening synthetic resin is injected into the gap between the hollow PC steel rod and the reaction force PC steel rod, the solid PC steel rod is removed even after the introduction of prestress. Since this is not done, the stress at the time of the action of the ultimate load can be applied to the solid PC steel rod, and the ultimate yield strength can be improved.

[0060]

As is apparent from the above description, according to the present invention, the following effects can be obtained. (1) Since prestress is introduced by the method of applying pretension to the hollow PC steel material, the sheath work and the grout work can be omitted, the construction period can be shortened, and the construction cost can be saved.

(2) Since the prestress is introduced by the method of applying the pretension, there is no set loss at the time of fixing and the introduced prestress can be managed with high accuracy.

(3) Since it is not necessary to perform the temporary tension fixing work as in the conventional example, and the tension fixing work is performed only once, the construction period can be shortened and the construction cost can be saved.

(4) Since it is not necessary to use anchor plates, nuts or the like for performing the temporary tension fixing work, the number of fixing tools used can be reduced and the construction cost can be saved.

(5) Even if a large cross-section force is applied to the existing side or expansion side concrete members, concrete members that have been constructed at different times are firmly integrated by introducing prestress without cracking the concrete members. Can be converted.

[Brief description of drawings]

FIG. 1 is a cross sectional view of a PC structure according to the present invention for an up lane (PC
It is a cross-sectional view showing an embodiment applied to a concrete floor slab of a PC bridge in which a girder) and a down lane (PC girder) are constructed in parallel.

FIG. 2 is a cross-sectional view showing a concrete floor slab of a PC bridge according to an embodiment.

FIG. 3 is a diagram showing an arrangement state of a PC steel material according to an embodiment.

4A is a plan view of a PC steel material according to an embodiment, and FIG. 4B is a sectional view of FIG.

FIG. 5 is a vertical cross-sectional explanatory view of a case where a tension force is introduced into a hollow PC steel rod by using an electric torque wrench device that is a tensioning and releasing device for PC steel material according to an embodiment.

6A to 6E are explanatory views showing a construction procedure of one embodiment.

7A and 7B are diagrams showing a gear case connected to the booster, in which FIG. 7A is a front view and FIG. 7B is a rear view.

FIG. 8 is a vertical sectional side view of a gear case.

FIG. 9 is an apparatus for tensioning and releasing a PC steel material according to one embodiment, which uses an electric torque wrench device to release a tension force to a hollow PC steel rod, so as to be opposed to an existing concrete member and a new concrete member. It is explanatory drawing about the case where a prestress is introduced.

FIG. 10 is a partially longitudinal side view showing a state in which a tensioning force is released into a hollow PC steel rod by using another tensioning and releasing device for a PC steel rod.

FIG. 11 is a partially cutaway plan view showing a state in which tension is being introduced into the hollow PC steel rod by using still another tensioning and releasing device for the PC steel rod.

12A and 12B are cross-sectional views of a second conventional example.

[Explanation of symbols] 1 PC bridge 2 Up lane (PC girder) 2a, 3a Floor slab 3 Down lane (PC girder) 4 Construction work vehicle 5 Splicing section 6 Existing concrete member 6a Concrete of existing concrete member 7 Additional concrete member 7a Concrete of expanded concrete member 8 PC steel material 9 Anchor plate (pressure bearing member) 10 End holder 11 Existing side hollow PC steel bar (existing side hollow PC steel material) 12 Expansion side hollow PC steel bar (expansion side hollow PC steel material) 13 Coupler ( Joining tool) 14 Notch portion 15 Anchor nut 16 Different diameter sleeve 16b Large diameter female screw 17 Reaction force PC steel rod (solid PC steel material) 18 Pushing piece (tensioning force applying member) 19 Stopper 19a Head 20 Electric torque wrench device 21 Electric torque wrench 22 Booster 22a Input shaft 22b Output shaft 22c Square shaft 23 Gear Box 23a housing 24 gear train 25 input gear 25a Sumijikugakarigoana 26 output gear 26a rotated for engagement hole 26b reaction force engagement hole 27 adhesion and anticorrosive synthetic resin 28 mortar 29 strain imparted and release device 30 concrete member 30a Concrete 31 Sheath 32 PC Steel Rod 33 Fixing Tool 34 Additional Concrete Member 34a Concrete 35 Sheath 36 PC Steel Rod 37 Coupler 38 Anchor Plate 39 Nut 40 Hydraulic Jack 41 Washer 42 Center Hole Jack 43 Rear Frame 44 Hollow PC Steel Rod Insertion Through hole 45 Front frame for reaction force support 46 Connecting rod 47 Frame type frame with jack 48 Divided pressure support member 49 Hollow piston 50 Screw rod 51 Rotating lever 52 Screw rod rotating drive shaft 55 Push-in relay rod 56 Non-circular member Aperture 57 anti Power chair 58 steel socket

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoru Kagoo 1586 Sotokawara Sotogawara, Aka City, Ako City, Hyogo Prefecture 1 Inside the Ako Plant of High Frequency Heat Smelting Co., Ltd. (56) Reference JP-A-7-252939 (JP, A) ) JP-A-56-150244 (JP, A) JP-A-8-151632 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) E04C 5/08 E04G 21/12 104 E04G 21 / 02 103

Claims (4)

(57) [Claims] 1. An existing hollow PC steel material, one end of which is provided with a bearing member is fixed in an existing concrete member, and the other end of which is extended to the additional concrete member side.
An extension side in which one end portion is joined to the extension end of the hollow PC steel material via a joint and penetrates the extension concrete member, and the other end portion is extended and arranged outside the extension concrete member. A hollow PC steel material and a solid PC inserted and arranged over the entire length of the hollow PC steel materials.
Steel, and the tension is applied to the hollow PC steel materials, the expansion concrete member is provided on the expansion side where concrete is poured and hardened, and the tension of the hollow PC steel rod is released. Pre-stress is introduced into both concrete members, and both concrete members are integrated, and an integrated PC structure of the existing concrete member and the additional concrete member. 2. An extension end of an existing hollow PC steel material, one end of which is provided with a bearing member is fixed in an existing concrete member, and the other end is extended to the extension concrete member side. , The expansion-side hollow PC steel material is joined to the expansion-side hollow P steel material by inserting a solid PC steel rod into the hollow PC steel materials, and then the solid PC steel material is connected to the expansion-side hollow P steel material.
By pushing the C steel material in such a way that a reaction force is exerted on the hollow PC steel materials, concrete is poured and hardened in order to build an additional concrete member in a state in which both hollow PC steel materials are pretensioned. By releasing the tension of the rod, prestress is introduced into both concrete members,
A method for constructing a PC structure for integrating concrete members at different construction times, characterized by integrating both concrete members. 3. A means for applying a tension force to the hollow PC steel rod or a means for releasing the tension engages with a different diameter sleeve screwed to the end of the hollow PC steel rod to take a reaction force. threaded to the different-diameter sleeve with which e Bei an engagement portion which is adapted
The tensioning / releasing device having an electric torque wrench having a rotation engaging portion that engages with the combined stopper is integrated into concrete members of different construction times according to claim 2. PC construction method. 4. The tensioning / releasing device includes a reaction force engaging portion that engages with the different diameter sleeve to generate a reaction force, and a stopper screwed to the different diameter sleeve.
A tensioning and releasing device comprising: a gearbox having a rotation engaging portion that engages with the clutch and an electric torque wrench connected to the gearbox via a power booster. The method for constructing a PC structure according to 3, wherein the concrete members having different construction times are integrated with each other.