JP4909810B2 - Construction method of concrete slab - Google Patents

Description

The present invention can omit the haunch portion formed on the lower surface of the bridge floor slab, particularly the floor slab, and further, by adjusting the support height of the bottom plate of the concrete formwork, on the construction method of adjustment can Turkey Nkurito deck in height.

  FIG. 7 shows an example of a concrete floor slab. A main girder 32 is supported on a support surface 30a of a bridge pier 30 via a support 31, and the main girder 32 facing each other is connected by a horizontal girder 33. A girder structure 34 is formed. The main girder 32 has a flange FL formed integrally or separately at the upper and lower ends of the web W to form an I-shape as a whole, and a concrete floor slab 35 is supported by the upper flange F.

  In many bridges, a haunch H is formed at a portion where the concrete floor slab 35 is supported by the main girder 32. The function of this haunch H absorbs the construction error of the main girder 32 (error generated in connection with the construction of the upper flange part), and the height of the floor slab road surface 35a of the concrete floor slab 35 of the bridge is set to a normal level. Adjusting means for height.

  The shape of the haunch H is asymmetrical between the main girder 32 due to the road alignment, and the shape of the haunch H may change every moment in the main girder axis direction. Further, since the height of the haunch H may need to be changed by adjusting the height of the floor slab road surface 35a, the shape of the haunch H does not continuously become the same shape in the main beam axis direction. It becomes very complicated.

  When the concrete floor slab 35 is constructed, a concrete formwork matching the outer shape of the concrete floor slab 35 including the shape of the haunch H must be prepared. As described above, since the shape of the haunch H is generally complicated, it is very complicated and expensive to manufacture a formwork matched to the size and shape and assemble it on site.

Therefore, Patent Document 1, Patent Document 2, and Patent Document 3 have been proposed with respect to a mold for accurately forming the portion of the haunch H.
Japanese Patent Laid-Open No. 2001-140219 JP 2000-290935 A Japanese Utility Model 1-36568

  In the invention described in Patent Document 1, a beam for supporting the divided formwork is provided in a portion where the haunch H is formed, and thereby the haunch formwork is supported. The mold that forms the portion of the haunch H is between the two molds to support the mold that forms the inclined portion of the haunch between the flat portion, the end of the mold and the main girder. A structure that prevents the formation of “small gaps” to be formed is necessary. For this purpose, it is necessary to prepare a mold having a complicated structure.

  Further, the invention described in Patent Document 2 divides the mold frame of the haunch H part into two parts, and connects the positions of both with adjustable bolts, and presses the end of the mold frame against the main girder. However, this structure also requires a complicated formwork and a complicated work for accurately adjusting the distance between the two formwork.

  Furthermore, the invention described in Patent Document 3 is intended to be formed as a single formwork including a portion that supports a haunch part as a formwork of a precast floor slab, but the formwork is large and heavy. And therefore, the handleability is poor, and moreover, it is expensive.

  As mentioned above, the haunch H is used for adjustment to absorb the construction error of the main girder and to make the floor slab surface height of the bridge a normal height, so it is adjusted as a formwork with a different shape depending on the position of the pier. Therefore, there is a drawback that the price of the mold is expensive and the work process for assembling it is complicated.

  As described above, in the construction structure of the conventional concrete floor slab, preparation of the form for forming the haunch H, complicated installation of the form, and difficulty in adjusting the height of the upper surface of the main girder, etc. There were various problems.

  Therefore, the present invention eliminates the haunch H required in the conventional concrete slab and can easily adjust the floor slab surface height, and a new assembly method and structure of the main girder and the slab. Is intended to provide.

  The construction method of the bridge concrete slab according to the present invention for achieving the above object is configured as follows.

  1) In the method of constructing a girder structure in which a plurality of main girders and a horizontal girder are connected to each other on the upper surface of the bridge pier, and further constructing a concrete floor slab on the upper part of the girder structure, The upper part of the main girder forming the girder penetrates the bottom plate of the concrete formwork and projects into the formwork, and the concrete is supported via a support device supported by using the main girder part projecting into the formwork. The mold frame is supported, the height of the bottom plate is adjusted, and the height of the road surface of the concrete floor slab formed by the mold frame is adjusted.

  2) In the method of constructing a girder structure in which a plurality of main girders and a horizontal girder are connected to each other on the upper surface of the pier, and further constructing a concrete floor slab on the upper part of the girder structure, The upper flange formed at the upper end of the web constituting the girder is omitted, and a through hole is provided in the upper edge of the web in the lateral direction, and the upper portion of the web passes through the bottom plate of the concrete formwork. A concrete floor slab road surface formed by projecting into a formwork, supporting the concrete formwork via a support device disposed on the top of the web, and adjusting the support height of the bottom plate by the support device. It is characterized by being configured to adjust the height.

  3) The support device includes a support bar that extends through the bottom plate of the concrete mold and extends above the upper end of the web, and a metal fitting that connects the upper part of the support bar and the flange of the main beam. It is characterized by being.

  The present invention provides a bottom plate support device that supports the upper part of a main girder constituting a girder structure through the bottom plate of a concrete formwork and protrudes into the formwork, and is supported by using the main girder part. The concrete formwork is supported via the base plate, and the height of the bottom plate is adjusted.

  Therefore, the height of the road surface of the concrete floor slab formed in the mold can be adjusted. In other words, the height of the bottom plate of the formwork is adjusted to adjust the height at which the upper part of the main girder protrudes into the formwork, and the “floor road surface height” can be adjusted by the operation.

  According to the above, since it is not necessary to form a “haunch” on the lower surface of the concrete slab, it is naturally not necessary to form a complicated form, and the form can be simplified. In addition, there are many advantages such as simplifying the work process, reducing the time required for assembling the formwork, and reducing various costs.

Example 1
1 and 2 are drawings showing a support structure for a concrete formwork when building a concrete floor slab for building a bridge according to a first embodiment of the present invention.

  Two (a plurality of) main girders 32 are arranged on a support surface 30a on the upper part of a concrete or steel pier 30 via a support 31 (not shown, but these main girders 32 are similar to FIG. 7). Are connected with a horizontal girder 33.) to form a girder structure 34.

  The girder structure 34 employed in this embodiment has the conventional structure shown in FIG. 7 having an upper flange F at the upper end of the web W constituting the main girder 32 and having an I-shaped section as a whole. I use it.

  In the present invention, the upper flange F and the upper portion of the web W connected thereto are embedded in the concrete of the concrete floor slab 35X and joined together, so that the height of the floor slab surface 35a, that is, the “construction error of the main girder 32”. "Is intended to absorb.

  As shown in FIGS. 1 and 2, the support rod 1 has a length extending through the mold bottom plate 5a for molding the concrete floor slab 35X and extending above the upper flange F, and provided with screw portions at both ends or the lower side thereof. The upper metal fitting 2 is arranged on the upper portion of the support rod 1 and the end portion of the upper metal fitting 2 is supported on the upper surface of the flange F. From the shape steel via the lower metal fitting 3 provided on the lower portion of the support rod 1 The receiving beam 4 is supported (FIG. 2). A concrete mold bottom plate 5 a is supported on the receiving beam 4.

  Accordingly, the "height h" between the bottom plate 5a and the upper flange F of the main girder 32 by operating the nut 1a or 1b screwed to the bolt formed at the end of the support bar 1, that is, The height of the bottom plate 5a is adjusted to accurately adjust the height of the floor slab surface 35a and the thickness of the concrete floor slab 35X. The support bar 1, the metal fittings 2, 3, the nuts 1a, 1b, etc. constitute a bottom plate support device S.

(How to adjust the height of the floor slab surface 35a)
As described above, in the present invention, when adjusting the distance h between the upper flange F of the main girder 32 and the inner surface of the concrete mold bottom plate 5a, the bottom plate supporting device S supported on the upper portion of the main girder 32 is provided. There is a feature in the point to use.

  The bottom plate support device S rotates a nut 1b (or an upper nut 1a) screwed into a lower portion of the support rod 1 (long bolts having a thread at both ends or lower ends, a kind of suspension bolt). By adjusting the height of the concrete formwork bottom plate 5a with respect to the position of the upper flange F of the girder 32, the thickness of the concrete constituting the concrete floor slab 35X is changed, or the concrete floor slab 35X is immersed inside. The length of the upper part of the main girder 32 is adjusted.

  6a and 6b are reinforcing bars, and the reinforcing bars 6a are continuous, but the reinforcing bars 6b are stopped at the web W portion of the main girder 32, and the reinforcing bars 6a and 6b are connected by the connecting bars 6c. The vertical space is maintained.

  The position where the reinforcing bar is arranged is not necessarily limited. For example, as shown in FIG. 3, a through hole is made in the web W, the reinforcing bar 6b is passed through this, and the connecting bar 6c is omitted. Also good.

  The upper metal fitting 2 constituting the bottom plate support device S is supported at the tip by the upper flange F of the main girder 32, and the lower metal fitting 3 is engaged and supported by the flange of the receiving beam 4.

  As for the structure of these metal fittings and the like, other types can be adopted. However, after placing the concrete, only the mold is removed and the lower end of the support bar 1 is cut. It is better to avoid using it.

  In this way, by adjusting the vertical position of the bottom plate 5a constituting the concrete formwork via the bottom plate support device S, the thickness of the concrete floor slab 35X formed on the bottom plate 5a is changed. The height of the floor slab surface 35a can be adjusted indirectly and accurately.

  The vertical position of the concrete formwork bottom plate 5a supported by the main girder 32 as described above is adjusted via the bottom plate support device S to adjust the depth at which the upper portion of the main girder 32 is embedded in the concrete floor slab 35X. Even though the bottom surface of the concrete floor slab 35X is flat, the same function as the haunch H in the conventional concrete floor slab 35 shown in FIG. 7 can be provided.

(Example 2)
FIG. 3 shows an example in which an upper flange of the main girder 32A is omitted. A through hole 8 is opened in a portion embedded in concrete, and a cross section L is formed in or near the through hole 8. The anchor material 9 of the mold is bolted. Then, the upper end of the support bar 10 is supported by using the anchor material 9, the lower surface of the receiving beam 4 is supported by the metal fitting 11 provided at the lower end, and the concrete formwork bottom plate 5 a is supported by the upper surface of the receiving beam 4. These members constitute the bottom plate support device S2.

  The through-hole 8 allows the floor slab concrete 35X (FIG. 1) on both sides of the web W to communicate with each other and has an effect of preventing displacement between the floor slab concrete 35X and the web W. It is also possible to increase the supporting force of the concrete slab 35X by penetrating the lower rebar 6b and further providing a slip prevention effect.

Example 3
In this embodiment, as in the case of the embodiment 2 shown in FIG. 3, an example using the main beam 32A in which the upper flange F is omitted is shown in FIGS.

  As shown in FIGS. 4 and 5, a through hole 8 is opened in the width direction of the concrete embedding portion on the upper side of the web W, and the concrete layers on both sides of the web W are communicated with each other through the through hole 8. This prevents the slippage between the concrete and the main girder 32A.

  In this embodiment, a support device S3 for adjusting the height of the bottom plate 5a of the concrete mold is provided at the upper edge of the web W. The support device S3 is composed of a support fitting 15 formed using a steel plate or the like arranged at the upper end of the web W, and two support rods 16 (bolts) arranged at both ends of the support fitting 15. The support position of the bottom plate 5a of the concrete mold is supported by the lower portion of the support bar 16 so as to be adjustable. And the height which supports the baseplate 5a is adjusted by operating one or both of the nuts 16a and 16b screwed to the screws provided at both ends of the support bar 16.

  If the nuts 16a and 16b screwed to the support bar 16 are adjusted as described above to adjust the position of the bottom plate 5a with respect to the web W of the main girder 32A, the bottom plate is supported by the support bracket 17 using L-shaped steel as necessary. 5a is fixed in that position. Further, the bottom plate portion 5b (portion protruding in a cantilever shape) not supported by the bottom plate support device S3 is supported by the expansion / contraction support device 18, and is operated in conjunction with the bottom plate support device S3 to make the bottom plate 5a flat. It is good to hold in the state.

Example 4
This embodiment shows an example in which a main girder 32 in which the upper flange F is omitted is used as in the case of the second and third embodiments.

  As shown in FIG. 6, a through hole 8 is opened in the width direction of the concrete embedding portion on the upper side of the web W, and the concrete layers on both sides of the web W are communicated with each other by the through hole 8. And the main girder 32A.

  The procedure for supporting the concrete formwork bottom plate 5a is basically the same as that of the third embodiment shown in FIGS. 4 and 5, but a high space is provided between the cross beam 33 and the bottom plate 5a in order to reduce the number of support devices S2. A height adjusting bolt 13 is attached to support the bottom plate 5a. The height of the bottom plate 5a can be finely adjusted by the height adjusting nut 13c.

  Although detailed description of the structure is omitted, it is preferable to prevent leakage of cement milk by arranging packing in the holes of the bottom plate 5a through which the support rods 1 (FIG. 1) and 10 (FIG. 3) pass. Moreover, it is good to arrange | position packing similarly to the contact part of the web W of the main girders 32 and 32A and the baseplate 5a, and to omit the complexity of the cleaning accompanying the leakage of cement milk.

  Construction of a concrete floor slab 35X using the bottom plate support device S (FIGS. 1, 2), S2 (FIG. 3), S3 (FIGS. 4, 5) and S4 (FIG. 6) of the concrete floor slab 35X according to the present invention. According to the method, a concrete floor slab 35X having a flat bottom surface and a structure in which a haunch (see FIG. 7) supported on the upper portion of the main girder 32 (32A) is omitted is easily constructed.

  As described above, according to the present invention, without forming a haunch between the concrete floor slab and the main girder, the construction error of the main girder is absorbed and the floor slab road surface height of the bridge can be simply set to a normal height. Therefore, the concrete floor slab can be constructed at a low cost.

It is a front sectional view of a concrete floor slab and a formwork concerning a 1st embodiment of the present invention. It is a perspective view of the support structure of the concrete formwork concerning a 1st embodiment. It is a perspective view of the support structure of the concrete formwork which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the support structure of the concrete formwork which concerns on the 3rd Embodiment of this invention. FIG. 5 is a cross-sectional view of a concrete formwork support structure related to FIG. 4. It is a perspective view of the support structure of the concrete formwork which concerns on the 4th Example of this invention. It is a perspective view which shows the structure of the conventional concrete floor slab.

Explanation of symbols

1,9,10,16 Support bar 1a, 1b, 16a, 16b Mounting bracket nut 2, 12, 15 Upper bracket
DESCRIPTION OF SYMBOLS 3 Lower metal fitting 3h Bottom plate through-hole 4 Receiving beam 5a Bottom plate 6a, 6b, 6c Reinforcing bar 8 Through-hole 9, 11 Mounting bracket 13 Height adjustment bolt 13a Spacer 13c Height adjustment nut 17 Mounting bracket 18 Support rod 30 Abutment 30a Top surface 31 Bearing 32 Main girder 32A Main girder without upper flange 33 Horizontal girder 34 Girder structure 35, 35X Concrete floor slab 35a Floor slab surface S, S2, S3, S4 Bottom plate support device (height adjustment device for bottom plate of formwork)
H Haunch W Main girder web F Main girder upper flange FL Main girder lower flange

Claims (3)

  In the method of constructing a girder structure in which a plurality of main girders and a horizontal girder are connected between the main girder on the upper surface of the pier, and further constructing a concrete floor slab on the upper part of the girder structure, the main girder is The upper part of the main girder to be formed penetrates the bottom plate of the concrete formwork and protrudes into the formwork, and the concrete formwork is placed through a support device arranged using the main girder part protruding into the formwork. A concrete floor slab construction method comprising: supporting and adjusting the height of the bottom plate by the support device to adjust the height of the road surface of the concrete floor slab formed by the formwork. In the method of constructing a girder structure in which a plurality of main girders and these main girders are connected with a horizontal girder on the upper surface of the pier, and further constructing a concrete floor slab on the upper part of the girder structure,
The upper flange formed at the upper end of the web constituting the main girder is omitted, and a through-hole is provided in the lateral direction on the upper edge of the web, and the upper part of the web passes through the bottom plate of the concrete formwork. Protruding into the formwork, and supporting the concrete formwork through a support device arranged using the upper part of the web to adjust the support height of the bottom plate, and formed in the concrete formwork features and to Turkey Nkurito construction technique for the floor plate by being configured to adjust the height of the road surface of the concrete slab. The support device includes a support bar that extends through the bottom plate of the concrete mold and extends above the upper end of the web, and a metal fitting that connects the upper part of the support bar and the flange of the main girder or the upper end of the web. The method for constructing a concrete slab according to claim 2 , wherein the concrete slab is constructed.

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