JP6365555B2 - Concrete floor slab replacement method - Google Patents

Description

  The present invention relates to a concrete floor slab replacement method that needs to be renewed due to aging in the bridge field.

  In the bridge field, as a method of replacing an existing concrete floor slab that has been renewed due to aging or the like with a new steel floor slab, a technique described in Patent Document 1 is known.

  If the technique described in Patent Document 1 is used, an existing steel girder and a new steel deck can be integrated without removing most of the existing concrete portions.

JP-A-62-45804

  However, in the technique described in Patent Document 1, a new steel floor slab is joined to an existing steel main girder with bolts, so that existing concrete and studs that are joined to the existing steel main girder with bolts are removed. However, it is necessary to drill the bolt holes with high accuracy. For this reason, there are concerns about the strength reduction and fatigue problems of the existing steel main girder due to the drilling of the bolt holes, as well as the reinforcement plate attached to the new steel deck and the bolt holes of the existing steel main girder. There was a problem that the accuracy control with the position was complicated and construction took time.

  The present invention has been made in view of the above circumstances, and when replacing an existing concrete slab with a new steel slab, it is possible to quickly install a new steel slab with a certain degree of accuracy. The object is to provide a concrete slab replacement method that can absorb errors and greatly improve the workability.

  In order to solve the above problems, the present invention has the following features.

  [1] When replacing an existing concrete floor slab installed on an existing steel main girder with a new steel floor slab, the existing concrete slab should be less than the upper flange width of the existing steel main girder. Cut and leave a part of the concrete floor slab above the steel main girder, and the horizontal girder installed on the lower surface of the new steel slab is intermittently spaced according to the upper flange width of the existing steel main girder. Open and install and integrate the new steel deck and the existing steel main girder by welding the horizontal girder of the new steel deck and the upper flange of the existing steel main girder by welding A replacement method for concrete floor slabs.

  [2] The method for replacing a concrete floor slab according to [1], wherein a buffer material is installed in a gap between the remaining existing concrete floor slab and the newly installed steel floor slab.

  In the present invention, when replacing an existing concrete slab with a new steel slab, it is possible to quickly install a new steel slab, absorb a certain degree of accuracy error, and greatly improve workability. Can be improved.

It is a figure which shows Embodiment 1 of this invention. It is a figure which shows Embodiment 1 of this invention. It is a figure which shows Embodiment 1 of this invention. It is a figure which shows Embodiment 1 of this invention. It is a figure which shows Embodiment 2 of this invention.

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

[Embodiment 1]
FIG. 1 is a cross-sectional view showing a structure (replacement structure of a concrete floor slab) after an existing concrete floor slab is replaced with a new steel floor slab by a concrete floor slab replacement method according to Embodiment 1 of the present invention. It is.

  As shown in FIG. 1, in the concrete floor slab replacement structure according to the first embodiment, the existing concrete floor slab 14 has an upper flange 11 in an existing steel main girder 10 (having an upper flange 11 and a lower flange 12). Cut with a width equal to or smaller than the width (here, the same width as the width of the upper flange 11), and the upper side of the steel main girder 10 is left. Moreover, the cross beam 24 (it has the same width as upper flange 11 width | variety here) matched with the position of the existing existing concrete floor slab 14 extended intermittently in a bridge width direction (bridge axis perpendicular direction) ( (Having a lower flange 25) is installed on the lower surface of a newly installed steel deck 21 (deck plate 22, vertical rib 23 (U rib, V rib, I rib, etc.)). And the remaining existing concrete floor slab 14 and the cut | interruption of the cross beam 24 fit, the lower flange 25 of the cross beam 24 installed in the lower surface of the newly installed steel floor plate 21, and the existing steel main girder Ten upper flanges 11 are joined by on-site welding (on-site welded portion 30), and the newly installed steel deck 21 and the existing steel main girder 10 are integrated.

  A buffer material (rubber, fiber, mortar, etc.) 26 is installed in the gap between the remaining existing concrete floor slab 14 and the newly installed steel floor slab 21 (deck plate 22).

  Next, the construction procedure for obtaining the above-described concrete floor slab replacement structure by the concrete floor slab replacement method according to the first embodiment of the present invention will be described.

  First, in order to ensure the rigidity in the transverse direction, the steel deck is usually installed with a predetermined interval (for example, an interval of about 2 m) in the longitudinal direction of the bridge (bridge axis direction). As shown in a longitudinal sectional view in a) and a bottom view in FIG. 2 (b), in this new steel deck 21, the cross beam 24 is aligned with the position of the upper flange 11 of the existing steel main beam 10. It is manufactured as a structure having cuts and extending intermittently in the bridge width direction.

  On the other hand, as shown in FIG. 3 (a), the existing concrete floor slab 13 is cut at the upper flange 11 width of the existing steel main girder 10, and the existing concrete floor slab 13 between the steel main girders 10 is cut. Remove. As a result, as shown in FIG. 3B, only the concrete slab 14 on the upper flange 11 of the existing steel main girder 10 remains. In addition, 15 in Fig.3 (a) is a stud.

  Then, as shown in FIG. 4, the new steel slab 21 is installed so that the cut of the cross beam 24 in the new steel slab 21 is fitted to the position of the remaining concrete slab 14.

  Finally, the lower flange 25 of the cross girder 24 installed on the lower surface of the newly installed steel deck 21 and the upper flange 11 of the existing steel main girder 10 are joined by field welding, The existing steel main girder 10 is integrated.

  In addition, since the remaining concrete floor slab 14 is a concrete floor board used for a long period of time, unevenness has arisen by the influence of heavy load etc., and height adjustment is often needed.

  Therefore, the height of the remaining concrete floor slab 14 is measured, and the remaining existing concrete floor slab 14 and the newly installed steel floor slab 21 (deck plate 22 are matched to the height of the cut in the new steel floor slab 21. ) And a cushioning material (hard rubber, fiber, mortar, etc.) 26 for smooth transmission of heavy load compression force applied to the steel deck by means of a vehicle that also serves as a height adjusting material. Good. The buffer material 26 is preferably a material that is suitable for long-term use, absorbs impact, and can withstand high heat during asphalt paving.

  Thus, in this Embodiment 1, when replacing the existing concrete floor slab 13 with the new steel floor slab 21, the new steel floor slab 21 can be quickly installed, and the new steel floor slab 21 can be installed. Because the lower flange 25 of the intermittent cross girder 24 and the upper flange 11 of the existing steel main girder 10 are joined by welding, adjustment by cutting at the construction site is also possible, and there is an accuracy error in the alignment of the existing structure Can be absorbed, and the workability can be greatly improved.

[Embodiment 2]
FIG. 5 is a longitudinal sectional view showing Embodiment 2 of the present invention. 5 (a) corresponds to FIG. 2 (a) in the first embodiment of the present invention, FIG. 5 (b) corresponds to FIG. 1 in the first embodiment of the present invention, and FIG. 5 (c) corresponds to FIG. This corresponds to FIG. 2C in the first embodiment.

  As shown in FIG. 5, the second embodiment of the present invention is basically the same as the first embodiment of the present invention described above, but in this second embodiment, a case where a large load is frequently applied or To cope with a case where the load cannot be supported only by field welding between the lower flange 25 of the cross girder 24 of the newly installed steel deck 21 and the upper flange 11 of the existing steel main girder 10 for some reason. The presser steel plate 31 extending in the bridge longitudinal direction is installed so as to connect the respective ends in the bridge width direction of the cross beams 24 installed at predetermined intervals in the bridge longitudinal direction, and the presser steel plate 31 is provided. The holes 32 are used for integration with an adhesive anchor (trade name: chemical anchor) 33 or the like.

  The presser steel plate 31 is provided over the entire length in the longitudinal direction of the bridge except for the portion where the cross beam 24 exists on the lower surface of the deck plate 22, and it is preferable that the presser steel plate 31 has a hole 32 in advance.

  Moreover, when the burden is not enough in the cross girder 24 of the newly installed steel deck 21, the workability of the adhesive anchor 33 can be improved by considering the workability and cost and performing the minimum necessary work.

  The application of the bridge to which the present invention is applied can also be considered for the new structure of the steel deck.

DESCRIPTION OF SYMBOLS 10 Existing steel main girder 11 Upper flange of existing steel main girder 12 Lower flange of existing steel main girder 13 Existing concrete slab 14 Remaining existing concrete slab 15 Stud 21 Steel slab 21
22 Deck plate 23 Vertical rib 24 Horizontal girder 25 Lower flange of horizontal girder 26 Cushioning material 30 On-site welded part 31 Steel plate 32 Hole 33 Adhesive anchor (chemical anchor)

Claims (2)

  When replacing an existing concrete slab installed on an existing steel main girder with a new steel slab, cut the existing concrete slab with a width less than the upper flange width of the existing steel main girder. A part of the concrete floor slab above the steel main girder is allowed to remain, and the horizontal girder installed on the lower surface of the new steel slab is installed at intervals according to the upper flange width of the existing steel main girder. The new steel deck and the existing steel main girder are integrated by welding the cross girder of the new steel deck and the upper flange of the existing steel main girder by welding. To replace concrete floor slabs.   2. The method for replacing a concrete floor slab according to claim 1, wherein a cushioning material is installed in a gap between the existing concrete floor slab that remains and a new steel floor slab.

Images