JP5041481B2 - Updating method and structure of existing bearing device - Google Patents

Description

  The present invention relates to an update method and an update structure of an existing bearing device in which an existing bearing device such as an elevated road bridge or a bridge is removed and updated to a new bearing device.

There is known a method of updating an existing bearing device in which a steel or elastic bearing device that fixes the base plate to the lower structure with an anchor bolt is replaced with a type B steel or elastic bearing device.
JP 2004-300957 A Road Bridge Specification (V Seismic Design) Japan Road Association, issued April 10, 2002 See 245

  When updating an existing bearing device, the updated bearing device is required to have improved seismic performance by the possession strength method. In order to meet this requirement, it is necessary to more reliably connect the updated and newly installed bearing device to the existing girders that are the superstructure.

  If the existing girder is made of steel, it can be easily reinforced by forming a build-up in the welded part that connects and fixes the steel existing girder and the sole plate, but it has the required seismic performance. When the girder is a concrete girder, the sole plate and the existing concrete girder are connected and fixed by anchor bolts. However, this connection fixing means has difficulty in increasing the strength of the connection fixing portion to the required seismic performance.

  The present invention solves the above-mentioned problems of the prior art, and provides an update method and an update structure for an existing bearing device that can easily connect and fix an existing concrete girder and an updated new bearing device and can improve seismic performance. The purpose is to provide.

The present first invention provides a method for updating the existing bearing device, after removing the existing bearing device on the undercarriage, rebar beyond the thickness of the concrete fog by working chipping the side and lower surface of the existing concrete girder is superstructure A space is formed inside and removed so that the reinforcing bar is completely exposed, and then the bottom plate, both side walls standing upright from the bottom plate, and the thickness of the concrete covering the both side walls are exceeded. A steel mounting member having a plurality of reinforcing and fixing ribs protruding so as to be positioned in the space inside the reinforcing bar with the tip portion exposed is disposed outside the concrete girder, and the concrete girder and the steel mounting A solidifying filler is filled between the members and solidified to be integrated.

  According to a second aspect of the present invention, in the method for updating an existing bearing device according to the first aspect of the present invention, a non-shrink mortar is used as the solidifying filler.

  The third invention is characterized in that, in the existing bearing device updating method of the first or second invention, the upper portion of the new bearing device and the bottom plate portion of the steel mounting member are fixed by welding or bolt connection. .

The fourth invention is an update structure for an existing bearing device, wherein an existing concrete girder is removed so that the bottom and side surfaces exceed the thickness of the concrete and a space is formed inside the reinforcing bar so that the reinforcing bar is completely exposed. And projecting so as to be located in the space inside the reinforcing bar where the tip portion is exposed across the cover concrete on both side wall portions, the both side wall portions standing vertically from the bottom plate portion, and the both side wall portions. A steel mounting member having reinforcing and fixing ribs is integrated with a solidifying filler, and the bottom plate portion of the steel mounting member is fixed to a new support device.

In the method for updating an existing bearing device according to the present invention, after removing the existing bearing device on the lower structure, the side and lower surface of the existing concrete girder which is the upper structure is moved over the thickness of the cover concrete by the lifting work and inside the rebar. A space is formed and the reinforcing bars are removed so that they are completely exposed, and then the bottom plate, both side walls standing upright from the bottom plate, and the thickness of the concrete covering the both side walls are over the tip. A steel mounting member having a plurality of reinforcing and fixing ribs protruding so as to be positioned in the space inside the exposed reinforcing bar is disposed outside the concrete girder, and the concrete girder and the steel mounting member With a structure in which a solidifying filler is filled and solidified in between, the reinforcing and fixing member of the steel mounting member is located in the rebar beyond the thickness of the cover concrete, so it is made of concrete. And steel mounting members are tightly integrated, improving the strength of the existing concrete girder support mounting part, and connecting and fixing with the new support device is also a steel-to-steel connection fixing, so welding, bolt fixing, etc. High-strength connection and fixation are possible, and seismic performance can be improved.
By using a non-shrink mortar as the solidifying filler, it is possible to prevent cracks during curing and to form a high-strength concrete frame.
It is possible to improve the seismic performance of the updated new support device by high strength connection and fixation by using steel that fixes the upper connection steel plate of the new support device and the bottom plate part of the steel mounting member by welding or bolt connection. it can.
In the renewal structure of an existing bearing device, an existing concrete girder that has been removed so that the bottom and side surfaces of the rebar exceed the thickness of the concrete and a space is formed inside the rebar and the rebar is completely exposed by the lifting work, and the outer side A bottom plate portion, both side wall portions erected vertically from the bottom plate portion, and reinforcing and fixing ribs protruding so as to be located in the space inside the reinforcing bar where the tip portion is exposed across the cover concrete on both side wall portions. The steel mounting member is integrated with a solidifying filler, and the bottom plate portion of the steel mounting member is fixed to a new support device, so that the reinforcing and fixing member of the steel mounting member is made of cover concrete. Since it is located in the reinforcing bar beyond the thickness, the concrete girder and steel mounting member are firmly integrated, improving the strength of the existing concrete girder support mounting part, and a new support device The connecting fixing also the connecting and fixing of the steel between the welding, connecting and fixing of the high-strength bolted like becomes possible, thereby improving the earthquake resistance.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a support device before renewal.

  The existing concrete girder 1 having an upper structure has a sole plate 2 fixed to the lower portion thereof by anchor bolts 3. An existing bearing device 6 is fixed by anchor bolts 5 on a concrete lower structure 4 such as a pier. The existing bearing device 6 includes a base plate 8 and an elastic bearing body 10. The sole plate 2 is placed on the elastic support body 10 of the existing support device 6, and the engaging portion of the side block 7 whose one end is fixed to the base plate 8 is engaged with the sole plate 2 and functions as an upper lift stop.

  In order to update to the new bearing device from the state shown in FIG. 1, the fixing of the side block that engages the existing bearing device 6 and the sole plate 2 is released, and the existing bearing device 6 is moved by lifting the lower structure 4. The anchor bolt 5 is removed until it is exposed, the anchor bolt 5 is cut, and the existing support device 6 is removed.

  Thereafter, the side surface and the bottom surface of the support device mounting portion of the existing concrete girder 1 are crushed and removed so that the internal rebar 14 is exposed beyond the thickness of the cover concrete. Then, it cut | disconnects so that the anchor bolt 3 may not protrude below the reinforcing bar 14, and the sole plate 2 is removed. FIG. 2 is a view showing the existing concrete girder 1 in a state where the hanging work is finished, the rebar 3 is cut, and the sole plate 2 is removed.

  FIG. 3 is a view showing a steel mounting member 24 arranged outside the existing concrete girder 1 in the state of FIG. The steel mounting member 24 has a bottom plate portion 25 and a pair of side wall portions 23 that stand vertically from the bottom plate portion. The interval between the side wall parts 23 is made substantially the same as the interval between the side walls of the existing concrete girder 1 before the suspension work. The side wall part 23 is formed in an L-shaped cross section by the horizontal plate part 23b and connecting means such as welding. Further, it may be formed integrally with the horizontal plate portion 23b to be L-shaped. The side wall portion 23 is fixed to the bottom plate portion 25 by connecting the horizontal plate portion 23 and the bottom plate portion 25 with a plurality of bolts 23a. The horizontal plate portion 23 b may be fixed to the bottom plate portion 25 by welding and the side wall portion 23 may be fixed to the bottom plate portion 25.

  The side wall 23 is fixed with a plurality of reinforcing and fixing portions 22 extending inward by welding. A part of the reinforcing and fixing part 22 has a protruding length so as to be located inside the reinforcing bar 14 in a state where the steel mounting member 24 is arranged on the outside of the existing concrete girder 1 after the hanging work shown in FIG. Have. For this reason, the reinforcing and fixing portion 22 is arranged at a position where it does not interfere with the reinforcing bar 14. The bottom plate portion 25 may also be provided with the reinforcing / fixing portion 22 disposed on the side wall portion 23. The reinforcing / fixing portion 22 shown in FIG. 3 is arranged in a state perpendicular to the bottom plate portion 25, but may be arranged in an oblique direction with respect to the bottom plate portion 25, or each of the oblique directions having different directions. It may be arranged in a direction. The number of reinforcing / fixing portions 22 arranged is appropriately designed. In addition, reinforcing ribs 26 facing outward are fixed to both side ends of the side wall portion 23 by welding.

  The steel mounting member 24 is positioned and arranged outside the existing concrete girder 1 after the suspension shown in FIG. After installing the formwork, a solidifying filler 34 such as a non-shrink mortar is filled and solidified, and the existing concrete girder 1 and the steel mounting member 24 are integrated to form a concrete girder 1A for bearing renewal. The bearing update concrete girder 1A improves the fixability by positioning the reinforcing and fixing portion 22 of the steel mounting member 24 beyond the concrete covered by the solidifying filler 34 in the reinforcing bar 14, thereby improving the bearing update concrete. The made girder 1A is made high strength.

  FIG. 4 is a view showing a state in which the bearing updating concrete girder 1A integrated with the steel mounting member 24 and the new bearing device 21 are connected and fixed. A new anchor bolt hole 17 is drilled in the lower structure 4 after the existing bearing device 6 is removed, and the new anchor bolt 20 is disposed. The new anchor bolt 20 is a short one, and its end is fixed to the reinforcing bar of the lower structure 4 by welding or the like in order to obtain a supporting force. The new base plate 18 is fixed to the new anchor bolt 20, and the new support device 21 in which the elastic layer 36 and the upper steel plate 35 are laminated on the new base plate 18 is placed. In the new bearing device 21, a shear key 37 having one end screwed to the new base plate 18 is disposed through the elastic layer 36 and the upper steel plate 35. Further, the shear key 37 passes through the newly installed sole plate 2A, and a nut 38 is screwed to the upper end of the shear key 37 by a recess formed in the newly installed sole plate 2A to connect the newly installed support device 21 and the newly installed sole plate 2A.

  Thereafter, the bottom plate portion 25 of the support updating concrete girder 1A integrated with the steel mounting member 24 and the new sole plate 2A are connected and fixed by welding or bolts. Since the new bearing device 21 and the bearing update concrete girder 1A are connected to each other, steel members can be connected to each other with high strength, and the seismic performance of the bearing device is improved.

  Thereafter, a solidifying filler 19 such as a non-shrinking mortar is driven into the lower structure 4 removed by the suspending operation, and the new support device 21 is fixed to the lower structure 4 via the anchor bolt 20.

  As an example of the new bearing device 21 shown in FIG. 4, an elastic bearing device in which the shear key 37 is arranged has been described as an example, but other bearing devices such as a steel bearing device may be used as the new bearing device.

  The steps of the updating method of the existing bearing device 6 are shown in FIGS. 5 (a) (b) (c) (d), 6 (a) (b) (c) (d), FIG. 7 (a) (b) (c). ) (D) and FIGS. 8 (a) and 8 (b).

  In the first step of the updating method of the existing bearing device 6 shown in FIG. 5A, the side block 7 connected to the base plate 8 with a bolt is removed. By removing the side block 7, the engagement between the existing support device 6 and the concrete girder 1 to which the sole plate 2 is fixed is released.

  In the second step shown in FIG. 5 (b), the lower structure 4 below the base plate 8 is removed by a lifting operation so that the anchor bolt 5 below the base plate 8 is exposed.

  In the third step shown in FIG. 5C, the anchor bolt 5 under the base plate 8 is cut. By cutting the anchor bolt 5, the existing support device 6 including the base plate 8 and the elastic support body 10 is not restrained by the upper and lower structures 1 and 4.

  In the fourth step shown in FIG. 5D, the existing support device 6 is removed.

  In the fifth step shown in FIG. 6 (a), the side surface and the lower surface of the existing concrete girder 1 are removed by the lifting operation until the rebar 14 is exposed beyond the thickness of the cover concrete.

  In the sixth step shown in FIG. 6 (b), the fixing of the sole plate 2 fixed by the anchor bolt 3 is released and removed.

  In the seventh step shown in FIG. 6C, a new anchor bolt hole 17 is drilled in the lower structure 4 in which the concave portion is formed by the suspending operation. The new anchor bolt hole 17 has a depth such that the reinforcing bar of the lower structure 4 is exposed.

  In the eighth step shown in FIG. 6D, the new anchor bolt 20 is disposed in the new anchor bolt hole 17. The new anchor bolt 20 is a short one, and in order to obtain a supporting force, the lower end portion thereof is fixed to the exposed reinforcing bar by welding or the like.

  In the ninth step shown in FIG. 7A, the new anchor bolt 20 is provided with the new base plate 18, the elastic layer 36, the new steel plate 35, and the new sole plate 2 A connected by the shear key 37. To do.

  In the tenth step shown in FIG. 7B, the steel mounting member 24 shown in FIG. 3 is positioned and arranged outside the existing concrete girder in a state where the reinforcing bar 14 is exposed by the lifting work.

  In the eleventh step shown in FIG. 7C, the newly installed sole plate 2A connected to the newly installed support device 21 and the bottom plate portion 25 of the steel mounting member 24 are fixed by fixing means such as welding or bolting.

  In the twelfth step shown in FIG. 7 (d), the formwork is assembled to the existing concrete girder and the steel mounting member 24 in a state where the reinforcing bars are exposed by the hanging work, and the solidifying filler 34 such as non-shrink mortar is struck. Set up.

  In the thirteenth step shown in FIG. 8 (a), a mold is assembled to the lower structure 4 in which the concave portion is formed by the suspending operation, and a solidifying filler 19 such as a non-shrink mortar is placed.

  In the fourteenth step shown in FIG. 8B, the solidified molds of the solidifying fillers 34 and 19 are removed and updated to the new support device 21 shown in FIG.

It is a figure which shows embodiment of this invention. It is a figure which shows embodiment of this invention. It is a figure which shows embodiment of this invention. It is a figure which shows embodiment of this invention. (A) (b) (c) (d) It is a figure which shows embodiment of this invention. (A) (b) (c) (d) It is a figure which shows embodiment of this invention. (A) (b) (c) (d) It is a figure which shows embodiment of this invention. (A) (b) It is a figure which shows embodiment of this invention.

Explanation of symbols

  1: Existing concrete girder, 1A: Concrete girder for bearing renewal, 2: Sole plate, 2A: Newly installed sole plate, 3: Anchor bolt, 4: Lower structure, 5: Anchor bolt, 6: Existing bearing device, 7: Side block, 8: base plate, 10: elastic support, 14: rebar, 17: hole for new anchor bolt, 18: new base plate, 19: solidifying filler, 20: new anchor bolt, 21: new support device, 22 Reinforcing and fixing ribs 23: Side wall portions 23a: Bolts 23b: Horizontal plate portions 24: Steel mounting members 25: Bottom plate portions 16: Reinforcing ribs 35: Upper steel plates 36: Elastic layers 37: Shear key, 38: Nut

Claims (4)

After removing the existing bearing device on the substructure,
By removing the side and bottom surfaces of the existing concrete girder that is the superstructure , the space is formed inside the rebar over the thickness of the cover concrete, and the rebar is completely exposed.
Thereafter, a bottom plate portion, both side wall portions erected vertically from the bottom plate portion, and a plurality of protrusions so as to be positioned in the space inside the reinforcing bar where the tip portion is exposed beyond the thickness of the concrete covering the both side wall portions A steel mounting member having a reinforcing and fixing rib is disposed outside the concrete girder, and a solidifying filler is filled between the concrete girder and the steel mounting member and solidified to be integrated. A method for updating an existing bearing device.   The method for renewing an existing bearing according to claim 1, wherein non-shrink mortar is used as the solidifying filler.   The method for updating an existing bearing device according to claim 1 or 2, wherein the upper portion of the new bearing device and the bottom plate portion of the steel mounting member are fixed by welding or bolt connection. An existing concrete girder whose bottom and side surfaces have exceeded the thickness of the concrete by lifting work and has been removed so that the rebar is completely exposed, and the bottom plate portion arranged on the outside, the bottom plate portion The steel mounting members having reinforcing and fixing ribs projecting so as to be positioned in the space inside the reinforcing bars where the tip ends are exposed beyond the concrete cover on both side walls, standing vertically from the two sides. A structure for updating an existing bearing device, characterized in that the bottom plate portion of the steel mounting member is integrated to a new bearing device.

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