JP5064245B2 - Joining method of PC beam and steel beam - Google Patents

Description

  The present invention relates to a method for joining a steel beam to an existing PC beam.

  As a viaduct type road, concrete bridge piers standing on the ground at intervals, RC (reinforced concrete) beams formed along the width direction of the roads provided at the upper part of each pier, and the RC beams One having a bridge girder laid over and a floor slab laid on the bridge girder is known.

  When this road is widened, part of the concrete at the end of the RC beam is connected to expose the internal reinforcing bars (reinforcing the concrete), and new reinforcing bars are welded to the exposed reinforcing bars. For example, a method of extending a RC beam by placing concrete on a reinforcing steel bar and placing a bridge girder for widening and a floor slab on the extended RC beam is used (see Patent Document 1).

JP 2002-81019 A

  In recent years, widening construction of viaduct type roads using PC (prestressed concrete) beams instead of the RC beams has been planned.

  In the case of a PC beam, a PC steel material formed from one end of the beam to the other in order to give compressive force to the concrete is installed in the beam, but separately from this PC steel material, a reinforcing bar for reinforcing the concrete Is not installed in the beam, the above method of adding rebar is impossible.

  Specifically, a bearing plate and a bearing nut for applying compressive force to the concrete are provided at both ends of the PC steel material in the PC beam, and these bearing plate and bearing nut are provided at both ends of the PC beam. Reinforcing bars are installed to hold the decorative concrete covering. However, this rebar only has the strength to hold the decorative concrete and is not for reinforcement, so even if a new rebar is added and concrete is placed, the required strength cannot be obtained. The construction method is impossible.

  In the case of PC beams, the strength of the concrete is increased by applying compressive force to the concrete using PC steel. Therefore, the side of the PC steel is exposed through the concrete around the PC steel, and the PC steel is newly added. The method of welding rebars cannot be used because the compressive force of concrete disappears.

  The object of the present invention, which was created in view of the above circumstances, is to provide a method capable of appropriately joining a steel beam to an existing PC beam as a method for widening a viaduct type road having a PC beam. It is to provide.

  In order to achieve the above object, the present invention is a method for joining a PC beam and a steel beam, wherein a plurality of anchor holes are drilled at the end of the PC beam and the end of the PC beam is covered. A through hole corresponding to the anchor hole is drilled in the tube, and the adhesive tube is covered with the joining tube on the end of the PC beam in a state where the adhesive is accommodated in the anchor hole. The anchor rod is inserted into the anchor hole from the through hole, the tip of the anchor rod is fixed with the adhesive in the anchor hole, and the nut is tightened to the threaded portion of the anchor rod protruding from the through hole. After fixing the joining tube to the PC beam, the steel beam is coupled to the joining tube.

  When the end of the PC beam is covered with the joining tube and the anchor hole and the through hole are aligned, the gap between the inner surface of the joining tube and the outer surface of the PC beam is set to the inside and outside of the joining tube. You may make it adjust with the screw jack with which it penetrated.

  You may make it inject | pour mortar into the said clearance gap after adjusting the clearance gap between the inner surface of the said joining cylinder and the outer surface of the said PC beam with the said screw jack.

  A joint formed by temporarily attaching a balance beam to one end of the joint tube and movably attaching a weight for balancing the joint tube to the balance beam when the joint tube is put on the end of the PC beam. Prepare a tube, balance beam, and weight unit, suspend the connection tube, balance beam, and weight unit from the wire of the crane so that the wire does not contact the bridge girder and floor slab placed above the PC beam. Then, the joining cylinder / balance beam / weight unit joining cylinder may be inserted into the end portion of the PC beam.

  After the joining cylinder / balance beam / weight unit joining cylinder is inserted and attached to the end of the PC beam, the weight is moved along the balance beam, and the position of the weight is changed to the joining cylinder / When the balance beam / weight unit obtained by detaching the connection tube from the balance beam / weight unit is suspended with a wire, the balance is taken, and then the temporary connection between the connection tube and the balance beam is released. The joining cylinder, the balance beam, and the weight unit may be separated from the joining cylinder, the weight unit may be obtained, and the balance beam and the weight unit may be separated from the joining cylinder in a state of being suspended by a wire.

  ADVANTAGE OF THE INVENTION According to this invention, a steel beam can be joined appropriately to the existing PC beam, and the widening construction of the viaduct type road which has a PC beam is attained.

  A preferred embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view of an existing viaduct type road.

  The viaduct road 1 includes a lower structure 2 installed on the ground and an upper structure 3 placed on the lower structure 2.

  The lower structure 2 includes a concrete pier 4 standing up and down in the front and back directions of FIG. 1, a PC beam 5 provided on the top of each pier 4 and formed along the width direction of the road, It has a support (shoe) 6 provided on the upper surface of each PC beam 5. The superstructure 3 includes a bridge girder 7 spanned on the support 6 of each PC beam 5 spaced in the front and back direction of FIG. 1 and a floor slab 8 laid on the bridge girder 7. The floor slab 8 is paved and becomes a substantial road, on which the car runs.

  A plurality of PC steel materials 9 for applying a compressive force to the concrete are installed inside the PC beam 5. The PC steel material 9 is formed in a rod shape from one end to the other end in the PC beam 5, and is equipped with a bearing plate 10 and a bearing nut 11 for holding the concrete at both ends and applying compressive force to the concrete. Yes. That is, both ends of the PC steel material 9 are inserted into holes formed in the bearing plate 10, and bearing nuts 11 are attached to both ends.

  The bearing plate 10 and the bearing nut 11 are covered with decorative concrete 12 provided at both ends of the PC beam 5. Specifically, the reinforcing bars 13 for holding the decorative concrete 12 are installed at both ends of the PC beam 5 so as to protrude outward from the support plate 10, and the decorative concrete 12 is applied to the reinforcing bars 13. It is installed. Such a reinforcing bar 13 has only strength to hold the decorative concrete 12 and does not reinforce the beam 5.

  The widening work of the viaduct type road having the PC beam 5 is performed as follows.

  First, as shown in FIG. 1, a plurality of anchor holes 14 are drilled at the end of the extended side of the PC beam 5 while avoiding the internal PC steel material 9 and the reinforcing bars 13. Specifically, the PC steel material 9 and the reinforcing bar 13 inside the PC beam 5 are detected using an X-ray sensor, an ultrasonic sensor or the like, and the anchor hole 14 is drilled at a position avoiding the PC steel material 9 and the reinforcing bar 13. Perforate. The anchor hole 14 is drilled in all or a part of the left and right side surfaces, the lower surface, and the upper surface of the end portion of the PC beam 5 according to the required bonding strength.

  If the anchor hole 14 is drilled at the end of the PC beam 5, the through hole 16 corresponding to the anchor hole 14 is drilled in the steel joining cylinder 15 shown in FIG. . Specifically, before the joining cylinder 15 is suspended by the wire 20, a film to which the position of the anchor hole 14 at the end of the PC beam 5 is transferred is attached to the joining cylinder 15, and the anchor hole 14 from above is attached. A through hole 16 corresponding to the above is drilled in the joining tube 15.

  Next, the joining tube 15 is put on the end portion of the PC beam 5, but before that, the surface of the end portion (the portion on which the joining tube 15 is put) of the PC beam 5 is roughened. This is to increase the adhesion strength of the resin mortar injected between the PC beams 5 after the joining cylinders 15 are covered. Further, the decorative concrete 12 at the end of the PC beam 5 is removed. This is because the decorative concrete 12 is not a strength member and therefore does not become a necessity as a connecting member.

  Further, before covering the end portion of the PC beam 5 with the joining cylinder 15, a capsule containing an adhesive is inserted into the anchor hole 14. This capsule is broken by an anchor rod inserted into the anchor hole 14 in a later step, and the anchor rod is fixed to the anchor hole 14 with an adhesive that flows out (bonding of a so-called chemical anchor (registered trademark) or the like). System anchor).

  Thereafter, as shown in FIG. 3, the joining cylinder 15 is put on the end of the PC beam 5, and the position of the through hole 16 of the joining cylinder 15 is matched with the position of the anchor hole 14 of the PC beam 5. Here, when the joining cylinder 15 is suspended by a crane wire alone, when the joining cylinder 15 is put on the end of the PC beam 5, the upper structure 3 (bridge girder 7) in which the wire is arranged on the upper part of the PC beam 5 is used. And the floor slab 8). Therefore, in the present embodiment, as shown in FIG. 2, the balance beam 17 is temporarily connected to one end of the joining tube 15 with a bolt nut or the like, and the weight 18 for balancing the joining tube 15 is moved to the balance beam 17. A connecting cylinder, a balance beam, and a weight unit 19 that can be attached are manufactured and suspended by a wire 20 of a crane.

  Specifically, two suspension fittings 21 are attached to each of the joining cylinder 15 of the joining cylinder / balance beam / weight unit 19 and the balance beam 17 in the front / back direction of the drawing in FIG. And the other ends of the wires 22 are connected together and connected to one wire 20 fed out from the crane. The wire 20 is positioned substantially directly above the position of the center of gravity of the joining cylinder / balance beam / weight unit 19, but the position of the center of gravity is separated from the joining cylinder 15 by the balance beam 17 and the weight 18. Therefore, as shown in FIG. 3, the joining tube 15 can be inserted into the end portion of the PC beam 5 without the wire 20 coming into contact with the upper structure 3.

  FIG. 4 is a perspective view showing a state in which the joining tube 15 is put on the end portion of the PC beam 5. In FIG. 4, a through hole 16 drilled in the joining cylinder 15 and a screw jack described later are omitted.

  The joining tube 15 is formed in a substantially rectangular tube shape from the ceiling plate 23, the left and right side plates 24, and the bottom plate 25. Specifically, the ceiling plate 23 is formed with a notch 26 in which the support 6 provided on the upper surface of the PC beam 5 is accommodated when the end of the PC beam 5 is covered with the joining cylinder 15. The side plate 24 is formed in a trapezoidal shape in accordance with the shape of the side of the end of the PC beam 5 where the end of the PC beam 5 is inserted, and the end of the steel beam 27 connected in a later process is connected. The portion to be formed is formed in a rectangular shape in accordance with the side surface shape of the end portion of the steel beam 27. In the bottom plate 25, the portion into which the end of the PC beam 5 is inserted is inclined according to the bottom shape of the end of the PC beam 5, and the portion to which the end of the steel beam 27 is connected is the end of the steel beam 27. It is formed horizontally according to the bottom shape of the part.

  When the joining cylinder 15 is put on the end of the PC beam 5, a predetermined gap (about 15 mm) is provided between the inner surface of the joining cylinder 15 and the outer surface of the PC beam 5. Is also slightly larger. As shown in FIG. 5, the gap 28 is adjusted to be equal in the vertical and horizontal directions by operating a screw jack 29 that is attached to the joining cylinder 15 so as to penetrate the joint cylinder 15. The screw jack 29 includes a nut 30 welded to the outer surface of the joining cylinder 15, and a bolt 32 that is screwed into the nut 30 and is inserted into a hole 31 formed through the joining cylinder 15. The shaft portion of the bolt 32 is pressed against the PC beam 5 by rotating the portion.

  Here, by operating a screw jack 29 provided on the ceiling plate 23 of the joining cylinder 15, the vertical position of the joining cylinder 15 with respect to the PC beam 5 can be adjusted, and the joining cylinder 15 with respect to the anchor hole 14 on the side surface of the PC beam 5. The vertical positions of the through-holes 16 on the side surfaces are matched. Further, by operating the screw jacks 29 provided on the left and right side plates 24 of the joining cylinder 15, the position of the joining cylinder 15 in the left-right direction in FIG. 5 (the front and back direction position in FIG. 3) relative to the PC beam 5 can be adjusted. The through-hole 16 in the road longitudinal direction of the ceiling surface and the bottom surface of the joining cylinder 15 with respect to the anchor hole 14 on the ceiling surface and the bottom surface of 5 is matched. 3 is applied to the joining cylinder 15 by an actuator (not shown) such as a winch or a jack attached to the PC beam 5, and the insertion depth of the joining cylinder 15 into the PC beam 5 is adjusted. Thereby, the road width direction position of each through-hole 16 with respect to each anchor hole 14 is matched.

  If the position of the through hole 16 of the joining cylinder 15 is aligned with the anchor hole 14 of the PC beam 5, the anchor rod 33 is inserted into the anchor hole 14 from the through hole 16 as shown in FIG. The capsule accommodated in the anchor hole 14 is broken, and the anchor rod 33 is fixed to the anchor hole 14 by the adhesive 34 flowing out from the capsule. As described above, the anchor hole 14 is provided to avoid the PC steel material 9 and the decorative concrete holding rebar 13. After fixing the anchor rod 33 to the anchor hole 14, the washer 35 is inserted into the threaded portion of the anchor rod 33 protruding from the through hole 16, the nut 36 is tightened, and the washer 35 is pressed against the outer surface of the joining cylinder 15. The joining tube 15 is fixed to the PC beam 5.

  Thereafter, the outer edge of the washer 35 is welded to the outer surface of the joining cylinder 15. Reference numeral 37 denotes a welded portion. This is to prevent the resin mortar from leaking from between the through hole 16 and the washer 35 of the joining cylinder 15 when the resin mortar is injected into the gap 28 between the joining cylinder 15 and the PC beam 5 in a later process. The nut 36 may be welded to the washer 35 to prevent loosening, and a washer-attached nut in which the washer 35 and the nut 36 are integrated, and the portion of the washer is welded to the outer surface of the joining cylinder 15. Also good.

  If the washer 35 is welded to the outer surface of the joining cylinder 15, resin mortar is injected into the gap 28 between the joining cylinder 15 and the PC beam 5. The injection is performed by injecting resin mortar through an injection hole (not shown) provided in communication with the inside and outside of the joining cylinder 15, and extracting the internal air from an air vent hole (not shown) provided in communication with the inside and outside of the joining cylinder 15. While doing. The resin mortar adheres to the PC beam 5 with high strength because the surface of the end portion of the PC beam 5 is roughened. Note that simple mortar may be used instead of resin mortar.

  After the resin mortar is cured, the balance beam 17 is separated from the joining tube 15 fixed to the end of the PC beam 5 as shown in FIG.

  Specifically, as shown in FIGS. 3 and 7, the weight 18 of the joined tube / balance beam / weight unit 19 is moved to the center side along the balance beam 17, and the position of the weight 18 is changed to the joined tube / balance beam. A balance beam / weight unit 38 obtained by detaching the joining cylinder 15 from the weight unit 19 is set to a position where balance can be obtained when the wire 20 is suspended by the wire 20. Thereafter, the wires 40 are attached to two suspension fittings 39 provided at the ends of the balance beam 17 at intervals in the front and back directions of FIGS. 3 and 7, and the wires 40 are attached to the suspension fittings at the other end of the balance beam 17. The wire 22 attached to 21 is combined and connected to one wire 20 fed out from the crane.

  The wire 20 is positioned substantially directly above the position of the center of gravity of the balance beam / weight unit 38, but the position of the center of gravity is positioned substantially at the center of the balance beam 17 by the balance beam 17 and the weight 18. Therefore, the wire 20 does not contact the upper structure 3. Thereafter, the wire 22 of the hanger 21 of the joining cylinder 17 is removed, the bolts and nuts that temporarily connected the balance beam 17 to the joining cylinder 15 are loosened and removed, and the balance beam 17 is separated from the joining cylinder 15 as shown in FIG. In this way, the balance beam / weight unit 38 is obtained, and the crane is operated with the balance beam / weight unit 38 suspended by the wire 20 to be separated from the joining cylinder 15.

  After removing the balance beam 17 from the joining cylinder 15, a steel beam 27 is connected to the end of the joining cylinder 15 as shown in FIG. 8. Specifically, the steel beam 27 is suspended from the wire of the crane, one end of the steel beam 27 is placed and fixed on the upper part of the steel bridge pier 41, and the other end of the steel beam 27 is connected to the joining cylinder 15. The end portion is abutted and connected by an attachment plate (seam plate) 42. A plurality of bolt insertion holes 43 are formed in the attachment plate 42, and through holes are formed in the steel beam 27 and the joining cylinder 15 in which the attachment plate 42 is disposed, according to the position of the insertion hole 43, The bolt is inserted into the insertion hole 43 and the through hole and fixed by the nut. A rivet may be used instead of the bolt.

  As described above, after the steel beam 27 is appropriately joined to the existing PC beam 5, the support 44 is provided on the steel beam 27, and the upper structure portion 45 for widening is placed thereon. The upper structure portion 45 includes a bridge girder 46 spanned on the support 44 of each steel beam 27 spaced in the front and back direction of FIG. 8, and a floor slab 47 for widening laid on the bridge girder 46. Have. The bridge girder 46 is connected and fixed to the existing bridge girder 7 with bolts or the like, and the floor slab 47 is connected to the existing floor slab 8.

  Thus, the widening work of the viaduct type road having the PC beam 5 can be appropriately performed.

It is sectional drawing of the existing viaduct type road. It is process drawing of the widening construction of the viaduct type road of FIG. FIG. 3 is a process diagram subsequent to FIG. 2. It is a perspective view which shows the state which covered the joining cylinder on the edge part of PC beam. It is a fragmentary sectional view of Drawing 4, and is an explanatory view of a screw jack. It is a fragmentary sectional view of Drawing 4, and is an explanatory view of an anchor hole and an anchor rod. FIG. 4 is a process diagram subsequent to FIG. 3. FIG. 8 is a flowchart subsequent to FIG. 7.

Explanation of symbols

5 PC beam 7 Bridge girder 8 Floor slab 9 PC steel material 14 Anchor hole 15 Joint tube 16 Through hole 17 Balance beam 18 Weight 19 Joint tube / balance beam / weight unit 20 Wire 27 Steel beam 28 Gap 29 Screw jack 33 Anchor rod 36 Nut 38 Balance beam / weight unit

Claims (5)

A method of joining a PC beam and a steel beam,
Drill multiple anchor holes at the end of the PC beam,
A through-hole corresponding to the anchor hole is drilled in the joining tube that covers the end of the PC beam,
In a state where the adhesive is accommodated in the anchor hole, the end of the PC beam is covered with the joining tube, and the position of the anchor hole and the through hole is adjusted.
An anchor rod is inserted into the anchor hole from the through hole, and the tip of the anchor rod is fixed with an adhesive in the anchor hole,
After fastening the nut to the threaded portion of the anchor rod protruding from the through hole and fixing the joint tube to the PC beam,
A method of joining a PC beam and a steel beam, wherein the steel beam is connected to the joining cylinder. When positioning the anchor hole and the through hole by covering the end portion of the PC beam with the joining tube,
The PC beam and the steel beam according to claim 1, wherein a gap between an inner surface of the joining tube and an outer surface of the PC beam is adjusted by a screw jack that is attached to the joining tube so as to penetrate the inside and outside of the joining tube. Joining method. The method for joining a PC beam and a steel beam according to claim 2, wherein a mortar is injected into the gap after adjusting a gap between an inner surface of the joining cylinder and an outer surface of the PC beam by the screw jack. When covering the joint tube on the end of the PC beam,
A connecting tube, a balance beam, and a weight unit are prepared by temporarily connecting a balance beam to one end of the connecting tube and movably attaching a weight to the balance beam to balance the connecting tube.
The joint cylinder / balance beam / weight unit is suspended from a crane wire so that the wire does not contact the bridge girder and the floor slab arranged on the upper part of the PC beam. The method of joining a PC beam and a steel beam according to any one of claims 1 to 3, wherein a joining cylinder is inserted and attached to an end portion of the PC beam. After inserting and attaching the joining tube of the joining tube / balance beam / weight unit to the end of the PC beam,
When the weight is moved along the balance beam, and the position of the weight is suspended by the wire with the balance beam / weight unit obtained by separating the connection tube from the connection tube / balance beam / weight unit. A position that can be balanced,
After that, the temporary connection between the joining tube and the balance beam is released, and the joining tube is separated from the joining tube / balance beam / weight unit to obtain the balance beam / weight unit, and the balance beam / weight unit is suspended by a wire. The method for joining a PC beam and a steel beam according to claim 4, wherein the PC beam and the steel beam are separated from the joining cylinder in a lowered state.

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