JP2006112171A - Diagonal anchoring nut mounting jig for diagonal tensioning bridge, and diagonal anchoring nut setting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diagonal anchoring nut mounting jig for a diagonal tensioning bridge, which facilitates safe lifting of a heavy anchoring nut for use in straining and adjusting a diagonal cable of the diagonal tensioning bridge, by using a crane facility, and facilitates rotation of the anchoring nut, to thereby quickly carry out fitting work of an anchoring block to a screw end. <P>SOLUTION: When the anchoring nut is screwed onto a screw portion formed on the anchoring block which is arranged at an end of the diagonal cable of the diagonal tensioning bridge, for straining the diagonal cable, tapping holes 21 are formed in a circumferential external surface of the anchoring nut 14, and screw members 22 each having a ball bearing 24 are inserted into the tapping holes. Then a circumferential ring 25 which is obtained by coupling two divided members 25a together, is provided for enclosing an external peripheral surface of the anchoring nut 14. The circumferential ring has a circumferential groove 26 formed in an internal peripheral edge thereof, into which the ball bearings 24 are fitted, and hoisting pieces 31 to be hoisted by hoisting equipment. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fixing nut mounting jig used in a fixing portion of an oblique cable in a cable-stayed bridge.

  The cable stayed bridge has a structure in which the main girder (bridge floor) is supported on the main tower by a large number of diagonal cables installed between the main tower and the main girder. As a bridge with a structure suitable for constructing a simple bridge, there is a growing recognition. FIG. 4 shows the appearance of a fan-type structure cable-stayed bridge. An oblique cable 3 is stretched between a main tower 1 and a main girder 2 of a box girder structure. After the stress is introduced, the ends are fixed to the main tower 1 and the main beam 2.

  The cable-stayed bridge is constructed by pre-tensioning a large number of PC steel materials between the main tower 1 and main girder 2 as described above, and finally the entire cable 3 with the PC steel materials bundled together. It is normal to adjust the tension so as to achieve the required tension. As shown in FIG. 6 (b), the oblique cable 3 is usually configured by bundling a large number of PC steel materials 33 twisted with strands and covering them with a covering material 34, and is fixed to both ends of the cable. It is a prefabricated cable with a block, and PC steel material 33 is inserted and inserted into a large number of through holes of the fixing block one by one, and is fixed with three wedges. A fixing nut is attached to the fixing screw portion of the fixing block. Each is attached, and the fixing nut is tightened and brought into contact with and engaged with the pressure bearing plate, so that the tension cable can be maintained in a semi-permanent state (the related structure is shown in FIG. 5 later). This will be described with reference to (b)).

  As mentioned above, cable-stayed bridges have recently been built with extremely large scales, and therefore the weight of the girders becomes large, so the main girder is suspended by the main tower. Therefore, the tension applied to the diagonal cable is also increasing. As a result, the device used for tension cable tension is also large and heavy, and it is desirable to install such a cable tension device easily. It is necessary to adjust the tension and maintain the tension state in a desired state.

Prestress greater than the amount of live load stress fluctuation expected in the main girder 2 is introduced to the diagonal cable 3 with a tensioning means such as a jack, and fixed to the fixing screw portion of the fixing block provided at the end of the diagonal cable. Japanese Patent Application Laid-Open No. 6-26012 (Prior Art 1), Japanese Patent Application Laid-Open No. 2001-200509 (Prior Art 2), etc. disclose the structure for fixing by tightening the nut.
Japanese Patent Laid-Open No. 6-26012 JP 2001-200509 A

  When attaching the fixing nut to the fixing screw provided on the outer periphery of the fixing block in order to introduce prestress to the diagonal cable, the fixing nut, which is a heavy object, is lifted to a predetermined height where the fixing screw end is located, It is necessary to fit the fixing screw portion. Since the fixing nut is heavy, it is usually lifted using a lifting equipment, but it is necessary to rotate the fixing nut so that it can be fitted to the fixing block in a suspended state. Requires effort and time. In other words, it is very difficult to perform the initial work of lifting the fixing nut, which is a heavy object, to a predetermined height, rotating it while keeping the state where it is applied to the fixing screw end, and screwing in a predetermined amount until it does not escape from the screw portion. In addition, there is no means that can easily solve this problem.

The present invention has been proposed in order to solve the above-mentioned problems, and it is possible to safely lift a heavy fixing nut for tension and adjustment of a diagonal cable in a cable-stayed bridge using a lifting equipment. An object of the present invention is to provide a fixing nut mounting jig and a method for setting the same, which can be easily rotated and quickly engaged with the screw end of the fixing block.

  In order to achieve the above object, the present invention is configured as follows.

  According to a first aspect of the present invention, there is provided a fixing block provided at an end portion of an oblique cable extending between a tower and a girder of a cable-stayed bridge, at the diagonal cable fixing portion of the tower or the girder, and the diagonal cable. The fixing nut mounting jig in the diagonal cable tensioning device in which the fixing nut is screwed to the threaded portion of the fixing block in a state where the fixing nut is pulled and tensioned in the extending direction, and is attached to the outer peripheral surface of the fixing nut. A circumferential ring that rotatably supports the fixing nut via a ball bearing with a threaded portion, and the fixing nut can be rotatably lifted and held via the circumferential ring. To do.

  According to a second invention, in the first invention, a tapped hole is provided in an outer peripheral surface of the fixing nut, and a screw portion of the ball bearing with the screw portion is fastened to the tapped hole, and the ball bearing is fitted into the circumferential ring. In addition to having a circumferential groove to be joined at the inner peripheral edge, it has a suspension piece that is lifted by a lifting device, and can be divided.

  According to a third invention, in the first invention, the circumferential ring is composed of a first and a second circumferential ring connected by a connecting member, and the cross section of the first circumferential ring is L. By providing ball bearings with threaded portions at right angles of the lever, the ball bearing is brought into contact with the outer peripheral surface and one end surface of the fixing nut, and the second circumferential ring is connected to the outer peripheral surface of the fixing nut. It is made to contact.

  According to a fourth aspect of the present invention, there is provided a method of setting a diagonal member fixing nut in a cable-stayed bridge, wherein a fixing block provided at an end of an oblique member cable spanned between the tower and the girder of the cable-stayed bridge, When the fixing nut is screwed onto the screw portion of the fixing block in a state where the diagonal cable is pulled and tensioned in the extending direction, a ball with a screw portion is provided on the outer peripheral surface of the fixing nut. A circumferential ring that rotatably supports the fixing nut via a bearing is arranged, and the circumferential ring is lifted by a lifting device, and the fixing nut is inclined to face the screw end of the fixing block to be a bearing. The fixing nut is rotated in a state where the nut load is applied, and is fitted to the fixing block.

According to the present invention, the fixing nut which is a heavy load can be rotatably supported on the circumferential ring, so that the fixing nut is lifted and held by the lifting device through the circumferential ring in a freely rotatable state, The fixing nut can be smoothly guided (moved) and fitted to the end of the fixing screw provided on the fixing block, and there is no need for complicated fixing nut support devices and equipment. Construction work is possible.

  Embodiments of the present invention will be described below with reference to the drawings.

  4 to 6 show the present invention in a cable-stayed bridge as a “one-sided suspension” type road bridge in which a diagonal cable 3 is installed between the main tower 1 and the main girder 2 at the center in the width direction of the girder. An applied example is shown. FIG. 5 (a) shows a part of the main girder 2 of the cable girder structure of the cable-stayed bridge, which is a cross-section in the longitudinal direction of the girder. The longitudinal direction of the spar of the hollow portion 4 is partitioned by a partition wall 5 at regular intervals.

  The upper slab 6 of the main girder 2 is provided with a raised portion 7 for fixing the lower end of the diagonal cable 3 intermittently in the longitudinal direction of the girder as shown in the figure. A tool fitting hole 8 is formed. The fixing tool fitting hole 8 is provided by setting a cylindrical fixing tool 10 (shown in FIG. 5b) at the lower end of the diagonal cable at a predetermined position before forming the raised portion 7, and then placing concrete. It is done. In addition, the installation angle of the fixing tool 10 changes in accordance with the installation angle of each diagonal cable 3 that is different from the main tower 1. A step counterbore 11 is provided at the lower end opening of the fixing tool fitting hole 8, and a support plate 12 is fitted therein, and a fixing block 19 fixed to the lower end of the diagonal cable is provided on the outer periphery thereof. A fixing nut 14 is screwed into the fixing screw portion 13 and is supported by the support plate 12.

  FIG. 6A shows a fixing structure of the upper end portion of the cable 3 of the cable stayed bridge. At the end of the diagonal cable 3 on the main tower 1 side, as shown in the figure, a cylindrical tower fixing tool 15 is fixed to the fitting hole 16 of the main tower 1, and the upper stage of the fitting hole 16 Corresponding to the bearing plate 18 assembled to the counterbore part 17, the fixing block 15a provided at the upper end of the diagonal cable 3 passing through the cylindrical fixing tool 15 is engaged, whereby the diagonal cable The upper end is fixed to the main tower 1.

  FIG. 5B shows a fixing structure fixing structure of the lower end portion of the cable 3 of the cable stayed bridge. In the fixing structure of the lower end of the diagonal cable, the cylindrical fixing tool 10 is fixed to the raised portion 7 of the main girder 2 formed by placing concrete as described above, and the diagonal fixing through the fixing tool 10 is performed. The lower end of the material cable 3 is connected to the fixing block 19, and the fixing nut 14 screwed to the fixing screw portion 13 for fixing the oblique material cable provided on the outer periphery of the fixing block 19 is engaged with the bearing plate 18 for fixing. The lower end of the diagonal cable is fixed through the block 19.

  The structure of the lower end of the diagonal cable 3 is fixed by stretching a large number of PC steel members constituting the diagonal cable 3 so as to widen each other in the trumpet pipe 20 housed in the cylinder of the fixing tool 10. One by one is inserted into each through hole of the block 19 and fixed individually with a wedge. Since the construction of the diagonal cable is the same as that of the existing cable, detailed description is omitted.

  A feature of the present invention is to provide a simple jig capable of freely lifting a fixing nut 14 which is a heavy object used in a fixing portion of an oblique cable 3 of a cable-stayed bridge. FIG. 3 shows the lifting jig according to the first embodiment, and FIGS. 7 and 8 show the lifting jig according to the second embodiment.

  The lifting jig of the first embodiment shown in FIGS. 1 to 3 includes a circumferential ring 25 as a main component, and uses the circumferential ring 25 to rotatably hold the fixing nut 14 at a predetermined height. The fixing block 19 can be easily and quickly fitted by being lifted by a lifting device such as a lever block.

  The configuration of the lifting jig according to the first embodiment will be described with reference to FIGS. The fixing nut 14 is configured as a ring nut having an internal thread 14a on the inner peripheral surface. A plurality of tap holes 21 are provided on the outer peripheral surface of the fixing nut 14 at intervals in the circumferential direction, and the screw portions of the ball bearings 22 with screw portions are screwed into the tap holes 21. A concave portion 23 is formed in the head of the ball bearing 22 with a threaded portion, and a ball bearing 24 is accommodated in the concave portion 23 so as to be rotatable and not to be detached.

The circumferential ring 25 is formed by having a circumferential groove 26 into which the ball bearing 24 on the head of the screw member 22 is fitted on the inner peripheral edge and detachably connecting a two-divided member 25a. That is, when the circumferential ring 25 is attached to the fixing nut 14, the outer periphery of the fixing nut 14 is held by the divided two-divided member 25a, and the bolt holes 28 of the connecting pieces 27 provided at both ends of the two-divided member 25a. The bolt 29 is inserted into the nut and the nut 30 is fastened to surround the fixing nut 14 so that the two-divided member 25a is integrated. A suspension piece 31 having an engagement hole 35 is provided on both lateral portions of the two-divided member 25a.

  In FIG. 1 to FIG. 3, the threaded portion of the threaded ball bearing 22 is fastened to the outer peripheral surface of the fixing nut 14 via the tap hole 21, but on the contrary, the threaded ball bearing 22 is attached to the circumferential ring 25. The ball bearing may be provided so as to rotate along the outer peripheral surface of the fixing nut 14 (a specific structure will be described in the second embodiment).

  When the fixing nut 14 is set on the fixing block 19 using the diagonal material fixing nut mounting jig according to the first embodiment, as shown in FIG. 3, the circumferential ring 25 that rotatably supports the fixing nut 14 is suspended. A lifting cable 32 of a lifting device such as a lever block is engaged with the piece 31 to lift the fixing nut 14 to a predetermined height and face the screw end of the fixing block 19 (shown in FIG. 5b). In this manner, the fixing nut 14 can be rotated and easily screwed into the fixing screw portion 13 with the nut load acting on the circumferential ring 25 via the ball bearing 24.

  After the fixing nut 14 is screwed into the fixing screw portion 13 for a predetermined length, the load of the fixing nut 14 is supported by the fixing block 19, so that the circumferential ring 25 is divided into two divided members 25a at this stage. Remove from 19. Thereafter, the fixing block 19 at the lower end of the diagonal cable is pulled and tensioned with a predetermined force in a direction extending the diagonal cable using a hydraulic jack device (not shown). It is filled by screwing in until it comes into contact, and the tension is ensured semipermanently.

  The diagonal jig fixing nut mounting jig according to the second embodiment will be described with reference to FIGS. In the second embodiment, a first circumferential ring 36 and a second circumferential ring 37 are arranged in parallel at a distance from both ends of the nut so as to surround the outer peripheral surface of the fixing nut 14. A plurality of threaded ball bearings 22 a are provided inside the first and second circumferential rings 36, 37 at equiangular intervals so that the ball bearings 24 can rotate along the outer peripheral surface of the fixing nut 14. Is provided.

  The first circumferential ring 36 is disposed on the lower end side of the fixing nut 14 that is held in an inclined manner in accordance with the inclination of the fixing block 19 (shown in FIG. 5b). A ball bearing 22a with a threaded portion is provided inside the portion 36a and the vertical portion 36b. Accordingly, the ball bearing 24 of one member 22 a rotates in contact with the outer peripheral surface of the fixing nut 14, and the ball bearing 24 of the other member 22 a rotates in contact with one end surface of the fixing nut 14.

  The second circumferential ring 37 is made of a flat steel plate having a predetermined width, and is disposed along the outer peripheral surface on the other end side of the fixing nut 14. The bearing 24 of the threaded bearing 22 a provided on the second circumferential ring 37 rotates in contact with the outer peripheral surface of the fixing nut 14. The first and second circumferential rings 36 and 37 are connected by a connecting portion plate 38 disposed at intervals of 90 ° in the circumferential direction. As the coupling means, the threaded portions 39 of the ball bearings 22a with threaded portions are inserted into the bolt holes of the first and second circumferential rings 36 and 37 and the connecting plate 38, and the nut 40 is fastened to the tip thereof. The first and second circumferential rings 36 and 37 are connected to the connecting plate 38. The threaded ball bearing 22a provided on the vertical piece 36b of the second circumferential ring 36 is also fixed by the same means as described above. Each connecting plate 38 is provided with a suspension piece 31 having an engagement hole 35.

  In the second embodiment, the fixing nut 14 is rotatably supported inside the first and second circumferential rings 36 and 37 as shown in FIG. 7, and the fixing nut 14 is shown in FIG. 8B. When the suspension piece 31 is lifted with the suspension piece 31 so that one end side thereof (the right end side in FIG. 8b) is on the upper side, the vertical end 36b of the first circumferential ring 36 is formed on the end surface on the lower end side of the fixing nut 14. Since the provided ball bearing 22a with a threaded portion is in contact with the rotation, in this state, the fixing nut 14 is applied with a load obliquely downward, but does not escape from the nut mounting jig, and rotates stably in an inclined state. Can be held freely.

  Therefore, according to the second embodiment, the fixing nut 14 can be inclined and opposed to the screw end portion of the fixing block 19 (shown in FIG. 5 b), and the nut load is applied to the circumferential ring 25 via the ball bearing 24. In this state, the fixing nut 14 can be rotated and easily screwed into the fixing screw portion 13. After the fixing nut 14 is fastened to the fixing block 19, it can be easily detached from the fixing nut 14 by moving the nut mounting jig obliquely downward.

When the fixing nuts 14 are provided at both ends of the diagonal cable 3 (that is, the main tower 1 side or the main girder 2 side), the tensioning jacks may be provided on the main tower 1 side. 2 may be provided on the fixing unit side. In the drawing, the fixing nut 14 is provided on the main beam 2 side. In addition, it is the same as the conventional point that the diagonal cable 3 is tensioned at the fixing part on the main girder 2 side and prestress is introduced, and then the grout is filled and injected into the diagonal cable pipe and the injection hole is closed with the grout cap. is there.

(A) is sectional drawing of the diagonal material fixing nut attachment jig which concerns on 1st Example of this invention, (b) is AA sectional drawing of the figure (b). It is the perspective view which the fixing nut and circumferential ring which concern on this invention isolate | separated. It is the perspective view which integrated the fixing nut and circumferential ring which concern on this invention. It is the figure which showed one example of the whole outline | summary of the cable-stayed bridge to which this invention is applied. (A) is a cross-sectional view of a cable-stayed bridge girder to which the present invention is applied, and is a cross-sectional view in the longitudinal direction of the girder. It is sectional drawing which shows the fixing structure of a girder side. (A) is sectional drawing which shows the fixing structure by the side of the main tower of the cable-stayed cable shown in FIG. 5, (b) is sectional drawing of a cable-stayed cable. (A) is sectional drawing of the diagonal material fixing nut attachment jig concerning 2nd Example of this invention, (b) is CC sectional drawing of the figure (b). (A) is a side view of the diagonal material fixing nut attachment jig which concerns on 2nd Example of this invention, (b) is a perspective view.

Explanation of symbols

1 Main tower
2 Main girder 3 Diagonal cable 4 Cavity part 5 Bulkhead 6 Upper slab 7 Raised part 8 Fixing tool insertion hole 10 Fixing tool 11 Stepped spot part 12 Bearing plate 13 Fixing screw part 14 Fixing nut 14a Female screw 15 Tower fixing tool 15a Fixing block 16 Fitting hole 17 Upper stepped spot facing 18 Supporting plate 19 Fixing block 20 Trumpet pipe 21 Tap hole 22 Ball bearing with screw part 23 Recess 24 Ball bearing 25 Circumferential ring 25a Dividing member 26 Circumferential groove 27 Connection Piece 28 Bolt hole 29 Bolt 30 Nut 31 Hanging piece 32 Lifting rope 33 PC steel material 34 Covering material
35 Engagement hole 36 1st circumferential ring 36a Horizontal part 36b Vertical part 37 2nd circumferential ring 38 Connection plate 39 Screw part 40 Nut

Claims (4)

  The fixing block provided at the end of the diagonal cable spanned between the tower and girder of the cable-stayed bridge is provided at the diagonal cable fixing part of the tower or girder, and the diagonal cable is pulled in the extending direction. A fixing nut mounting jig in an oblique cable tensioning device in which a fixing nut is screwed into a threaded portion of the fixing block in a tensioned state, and a ball bearing with a threaded portion on an outer peripheral surface of the fixing nut A circumferential ring that rotatably supports the fixing nut via a circumferential ring is provided, and the fixing nut is rotatably lifted and held via the circumferential ring. Fixing nut fixing jig.   2. A tapped hole is provided in an outer peripheral surface of the fixing nut, and a threaded portion of the ball bearing with the threaded portion is fastened to the fixing nut, and the circumferential ring has a circumferential groove into which the ball bearing is fitted. A jig for fixing an oblique material fixing nut in a cable-stayed bridge, characterized in that it has an inner peripheral edge, has a suspension piece that is lifted by a lifting device, and can be divided.   2. The circumferential ring according to claim 1, wherein the circumferential ring is composed of first and second circumferential rings connected by a connecting member, and the first circumferential ring has a cross-section L and is perpendicular to each part thereof. By disposing a ball bearing with a threaded portion, the ball bearing is brought into contact with the outer peripheral surface and one side end surface of the fixing nut, and the second circumferential ring is in contact with the outer peripheral surface of the fixing nut. Features a diagonal fixing nut mounting jig.   The fixing block provided at the end of the diagonal cable spanned between the tower and girder of the cable-stayed bridge is provided at the diagonal cable fixing part of the tower or girder, and the diagonal cable is pulled in the extending direction. When the fixing nut is screwed onto the screw portion of the fixing block in a tensioned state, a circumferential ring that rotatably supports the fixing nut is disposed on the outer peripheral surface of the fixing nut via a ball bearing with a screw portion. In addition, the circumferential ring is lifted by a lifting device, and the fixing nut is inclined to face the screw end of the fixing block, and the fixing nut is rotated while the nut load is applied to the bearing, and is fitted to the fixing block. A method for setting a diagonal fixing nut in a cable-stayed bridge, characterized by

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