JP2006307561A - Method of manufacturing corrugated steel sheet web prestressed concrete beam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently manufacture a precast corrugated steel sheet web PC beam by a partition plate system so that the connection end part of a corrugated steel sheet is not projected from a concrete to form an obstacle. <P>SOLUTION: The corrugated steel sheets 11 and 12 of the corrugated steel sheet web PC beam adjacent to each other are joined to each other through temporary splicing plates 30 through a clearance 13 provided to the abutting part thereof. A form 60 comprising an upper floor slab form 61, a lower floor slab form 62, and a form frame 63 holding these molds is assembled therearound, and the concrete is deposited between the upper floor slab forms 61 and 61b and the lower floor slab forms 62a and 62b while holding partition plates 51 and 52 thinner by a dimensional amount equal to the contracted amount of the concrete from the dimension of the clearance 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a corrugated steel web PC girder for producing a precast corrugated steel web PC girder using a corrugated steel web.

  When constructing a long bridge, the so-called precast segment construction method for producing a bridge body of an upper structure is increasing in parallel with the construction of a lower structure such as an abutment or a pier. According to this construction method, there is an advantage that a long bridge can be constructed in a short construction period and a high-quality concrete segment can be obtained in a well-equipped factory or an adjacent production yard. In this case, the bridge is constructed using a precast concrete segment having a shape obtained by cutting the bridge body into a ring.

  Conventionally, a match cast method and a partition plate method are known as a method for producing a concrete segment in the precast segment method.

  The match cast method uses the end face of the prefabricated concrete segment as a formwork for the end face of the postfabricated concrete segment, and casts the concrete of the postfabricated concrete segment to produce a concrete segment whose end face shape matches perfectly. It is a method. Therefore, according to the match cast method, the joint surface when assembling the concrete segment is constructed with high accuracy.

  In addition, the partition plate method is a method in which concrete is placed in a formwork in which a partition plate is inserted for each length of a concrete segment to be manufactured, and a plurality of concrete segments are manufactured at one time (for example, non-patent literature). 1).

  In the above-mentioned match cast method, it is necessary to make a pre-manufactured concrete segment in advance. On the other hand, in the partition plate method, a plurality of concrete segments can be manufactured at one time. A large number of concrete segments can be manufactured in a shorter construction period than when a concrete segment is manufactured using a casting method.

  In recent years, corrugated steel web girders using corrugated steel sheets for webs have been developed and put into practical use. In the corrugated steel web girder, the weight of the upper structure can be significantly reduced by using a steel plate that is lighter than concrete for the web that occupies about 25% of its own weight. Therefore, it is possible to reduce the size of the lower structure and reduce the construction cost. In addition, since a concrete web is not required, the work of assembling and disassembling the formwork and reinforcing bars is reduced, and labor saving and shortening of the construction period are possible.

The corrugated steel web girder having such advantages has been conventionally manufactured by the cast-in-place method, but by manufacturing the corrugated steel web girder by applying the above-mentioned precast segment method, further labor saving of construction can be achieved. The construction cost can be reduced by shortening the construction period and shortening the construction period. In particular, if the partition plate method of the precast segment method is applied, the effect of shortening the work period is great.
“Prestressed concrete T bridge road bridge design and construction guidelines by precast block method”, Japan Road Association, October 5, 1992, p. 28

  In general, it is known that cast concrete has a property of shrinking when it is cured.

  Therefore, when the precast segment method is applied to manufacture the corrugated steel web girder and concrete is placed on the upper and lower floor slabs on which the corrugated steel is disposed, the corrugated steel does not shrink, so the placed concrete is hardened. When this occurs, the corrugated steel sheet may protrude from the end face of the segment by an amount equal to the amount of shrinkage in the longitudinal direction of the concrete. As a result, the corrugated steel plate protruding from the end face becomes an obstacle, and there arises a problem that the concrete joint processing becomes difficult when the segments are connected at the site.

  In view of the above circumstances, an object of the present invention is to provide a rational manufacturing method of a corrugated steel web PC girder for producing a corrugated steel web PC girder by a precast segment method. In the present invention, the PC girder includes a single row PCT girder and a plurality of PC box girder webs.

  The manufacturing method of the corrugated steel web PC girder according to the present invention that achieves the above object is to produce a PC girder segment using the corrugated steel web by matching the corrugated steel plates of the segments adjacent in the longitudinal direction of the girder through a gap. The upper and lower floor slab forms are attached to the corrugated steel plates, and concrete is placed with a partition plate thinner than the gap between adjacent upper and lower floor slab forms.

  Since the method for manufacturing the corrugated steel web PC girder according to the present invention is for placing concrete with a partition plate thinner than the above gap between adjacent upper and lower floor slab formwork, at the stage where the concrete is placed, Each corrugated steel sheet is disposed in a state of being retracted from each end face of the adjacent floor slab concrete by the difference between the dimension and the thickness dimension of the partition plate. As a result, even if the cast concrete is hardened and shrunk, the difference between the gap dimension and the thickness of the partition plate offsets the amount of shrinkage in the longitudinal direction of the floor slab concrete and requires special joint treatment, etc. The end surfaces of the floor slab concrete of each manufactured PC girder segment can be joined together.

  Therefore, according to the manufacturing method of the corrugated steel web PC girder of the present invention, the PC girder segment using the corrugated steel web can be manufactured by the same partition plate method as that of the prior art. The labor cost can be reduced by saving labor, shortening the construction period, and shortening the construction period.

  Here, in the manufacturing method of the corrugated steel web PC girder according to the present invention, the difference between the gap dimension and the thickness dimension of the partition plate is equal to or slightly larger than the longitudinal contraction amount of the slab concrete. Is preferred. According to such a preferable form, the end surfaces of floor slab concrete of each manufactured PC girder segment and corrugated steel sheets can be joined with high accuracy.

  According to the method for manufacturing a corrugated steel web PC girder according to the present invention, at the stage where concrete is placed, each corrugated steel sheet is different from the adjacent floor slab concrete by the difference between the gap dimension and the partition wall thickness dimension. It will be arrange | positioned in the state withdrawn rather than each end surface. Therefore, when the cast concrete is hardened and shrunk, the difference in the longitudinal direction of the slab concrete is offset by the difference, and the floor slab of each PC girder segment manufactured without requiring special joint treatment or the like. The end surfaces of the concrete can be joined with high accuracy by ordinary joining means.

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

  FIG. 4 is a side view of a corrugated steel web PCT girder manufactured by applying one embodiment of a method for producing a corrugated steel web PC girder according to the present invention, and FIG. 5 is a corrugated steel web PCT girder shown in FIG. FIG. 6 is a perspective view of the corrugated steel sheet seen through from the upper floor slab concrete side of the corrugated steel web PCT girders shown in FIG.

  Hereinafter, a process of manufacturing the corrugated steel web PCT girders 1 which are examples of the corrugated steel web PC girders of the present invention using the corrugated steel plates 10 shown in FIGS. 4 to 6 will be described. Here, as the method of joining the corrugated steel sheet 10 and the upper and lower floor slab concrete 21, 22 in the corrugated steel sheet web PCT girder 1, the upper and lower ends of the corrugated steel sheet 10 are embedded in the upper floor slab concrete 21 and the lower floor slab concrete 22. An example in which an embedded joining method for joining the corrugated steel sheet 10 and the upper and lower floor slab concrete 21 and 22 is applied will be described. In addition, as a joining system of the corrugated steel plate 10 and the upper and lower floor slab concrete 21 and 22, for example, a stud joining system for joining the corrugated steel sheet and the upper and lower floor slab concrete via a flange plate in which a stud diver is fused, or the like. The Giberl format may be applied.

  Next, the process of the present invention will be described.

  FIG. 7 is a side view showing the corrugated steel sheet disposing process of the embodiment.

  First, as shown in FIG. 7, the corrugated steel plates 11 and 12 of the segments adjacent to each other in the longitudinal direction of the girders are arranged to face each other through the gap 13 (corrugated steel plate arranging step).

  FIG. 7 shows a portion in the vicinity of the joining end portion of the corrugated steel plates 11 and 12 of the adjacent corrugated steel plates 10 used in the corrugated steel web PCT girders 1 shown in FIGS. As shown in FIG. 7, the corrugated steel plates 11 and 12 of the segment adjacent to the longitudinal direction of the girder are disposed with a gap 13 at the joint end. Holes 11a and 12a for attaching temporary attachment plates and permanent attachment plates, which will be described later, are provided in the vicinity of the joining end portions where the corrugated steel plates 11 and 12 are abutted.

  Next, the corrugated steel sheet joining step shown in FIG. 8 is entered. FIG. 8 is a side view showing the corrugated steel sheet joining step of the example.

  As shown in FIG. 8, the corrugated steel plates 11, 12 arranged to face each other through the gap 13 in the corrugated steel plate arranging step are joined by a temporary attachment plate 30 (corrugated steel plate joining step).

  The corrugated steel plates 11, 12 that are abutted through the gap 13 are joined by fixing the temporary attachment plate 30 with bolts 41 in holes 11 a, 12 a (see FIG. 7) provided in the corrugated steel plates 11, 12. To do.

  Next, the mold attachment process shown in FIGS. FIG. 1 is a side view showing the mold attachment process of the embodiment, FIG. 2 is a view taken along the line AA in FIG. 1, and FIG. 3 is a view taken along the line BB in FIG.

  As shown in FIGS. 1 to 3, a mold 60 is assembled around the corrugated steel plates joined in the corrugated steel plate joining step. The mold 60 includes an upper floor mold 61, a lower floor mold 62, and a mold frame 63 for holding them. Partition plates 51 and 52 that are thinner than the gap 13 are sandwiched between adjacent upper floor molds 61a and 61b and lower floor molds 62a and 62b (mold attachment step).

  As shown in FIGS. 1 and 2, a mold 60 is assembled around the corrugated steel plates 11 and 12 joined together by the temporary attachment plate 30 through the gap 13. In addition, in this embodiment, since the corrugated steel plates 11 and 12 and the upper and lower floor slab concrete 21 and 22 are joined by an embedded joining method, the upper end portions 11b and 12b and the lower end portions 11c and 12c of the corrugated steel plates 11 and 12 are respectively provided. The concrete of the formwork 60 is disposed in the portion where the concrete is placed.

  As shown in FIGS. 1 and 3, partition plates 51 and 52 thinner than the size of the gap 13 are sandwiched between adjacent upper floor molds 61 a and 61 b and lower floor molds 62 a and 62 b. In addition, when inserting the partition plates 51 and 52, it inserts so that the center of the thickness direction of the partition plates 51 and 52 and the center of the clearance gap 13 may correspond. Further, the difference between the dimension of the gap 13 and the thickness dimension of the partition plates 51 and 52 is set to a value equal to or slightly larger than the amount of shrinkage in the longitudinal direction of the upper and lower floor slab concrete 21 and 22. By doing so, when the longitudinal lengths of the upper and lower floor slab concrete 21 and 22 of each manufactured PCT girder segment contract, the butt end portion of the corrugated steel sheet which does not contract protrudes from the concrete end surface and joins the upper and lower floor slab end surfaces. This eliminates the problem of difficulty. Therefore, the concrete end surfaces and the corrugated steel plates 11 and 12 can be joined with high accuracy.

  Next, the concrete placement process shown in FIG. 9 is entered. FIG. 9 is a side view showing the concrete placing process of the embodiment.

  As shown in FIG. 9, concrete is cast and cured on the mold 60 assembled in the mold mounting process, and the mold 60 is removed (concrete casting process).

  The upper and lower floor slab concrete 21 and 22 are cast and cured, and the frame 60 (see FIGS. 1 to 3) is removed. The upper end portions 11b and 12b and the lower end portions 11c and 12c of the corrugated steel plates 11 and 12 are embedded in the upper and lower floor slab concrete 21 and 22, and the corrugated steel plates 11 and 12 and the upper and lower floor slab concrete 21 and 22 are joined. The

  In the present invention, a partition having a thickness smaller than the gap 13 between the corrugated steel plates 11 and 12 joined by the temporary attachment plate 30 between the adjacent upper floor molds 61a and 61b and the lower floor molds 62a and 62b. Concretes 21 and 22 are placed across the plates 51 and 52.

  Specific dimensions of the thickness of the gap 13 and the partition plates 51 and 52 are related to the shrinkage allowance of the concrete. The amount of shrinkage of the concrete can be determined according to the constituent material of the concrete, the composition, the size of the concrete, the placement conditions, the curing conditions, and others. For example, in one embodiment of the present invention, in a high-strength PCT girder segment having a width of 2 m and a segment length of about 3 m, the size of the gap 13 is set to 12 mm, and the thickness of the partition plates 51 and 52 is set to 9 mm. Accordingly, the corrugated steel plates 11 and 12 are more than the end surfaces of the adjacent upper and lower floor slab concrete by the difference (3 mm) between the dimension of the gap 13 (12 mm) and the thickness dimension (9 mm) of the partition plates 51 and 52. It will be arranged in the retracted state.

  Next, the segment separation process shown in FIG. 10 is entered. FIG. 10 is a side view showing the segment separation process of the embodiment.

  As shown in FIG. 10, each PCT girder segment from which the formwork 60 has been removed in the concrete placing step is separated (segment separation step).

  The temporary splicing plate 30 connecting the corrugated steel plates 11 and 12 is removed, and the PCT girder segments are separated by moving horizontally. Moreover, the partition plates 51 and 52 sandwiched between the adjacent upper and lower floor slab concrete 21 and 22 are also removed.

  Finally, the segment connection process shown in FIG. 11 is entered. FIG. 11 is a side view showing the segment connecting step of the embodiment.

  As shown in FIG. 11, each PCT girder segment manufactured through the corrugated steel sheet arranging step to the segment separating step is connected on site (segment connecting step).

  After separating each PCT girder segment in the segment separation process, even if the concrete hardens and shrinks until the upper and lower floor slab concrete 21 and 22 are completely cured, the dimension of the gap 13 (12 mm) and the thickness of the partition plate The difference (3 mm) from (9 mm) cancels the longitudinal longitudinal shrinkage of the upper and lower floor slab concrete 21, 22, and the joined ends of the corrugated steel plates 11, 12 protrude from the end surfaces of the upper and lower floor slab concrete 21, 22. Therefore, the end surfaces of the upper and lower floor slab concrete 21 and 22 of each manufactured PCT girder segment can be easily joined with high accuracy.

  An epoxy resin adhesive is applied to the respective end surfaces of the upper and lower floor slab concrete 21 and 22, the end surfaces of the upper and lower floor slab concrete 21 and 22 are joined together, and prestress is introduced into each of the upper and lower floor slab concrete 21 and 22. Further, the corrugated steel plates 11 and 12 are coupled to each other by fixing the main joining plate 70 with bolts 42 in the holes 11 a and 12 a provided in the corrugated steel plates 11 and 12. In this way, each PCT digit segment is connected in the field.

  As described above, according to the method for manufacturing a corrugated steel web PC girder according to the present embodiment, a PC girder segment using the corrugated steel web can be efficiently and accurately manufactured by the partition plate method. Labor saving of construction of web PC girder, shortening of construction period, and reduction of construction cost by shortening construction period are possible.

  In the above-described embodiment, an example in which the web is a single row PCT digit is used as the PC digit of the present invention. However, the present invention is not limited to this, and the web is a multi-column PC box digit. May be.

  In the above-described embodiment, the corrugated steel sheet and the upper and lower floor slab concrete are embedded by embedding the upper and lower ends of the corrugated steel sheet in the upper floor slab concrete and the lower floor slab concrete. Although the example which applied the embedding joining system which joins was given, the manufacturing method of the corrugated steel web PC girder of the present invention is, for example, corrugated steel and upper and lower floor slab concrete via a flange plate in which stud gibber is fused. The present invention may be applied to a precast girder of a stud joint system or other gibber type to be joined.

It is a side view which shows the mold attachment process of an Example. It is an AA arrow line view of FIG. It is a BB arrow line view of FIG. 1 is a side view of a corrugated steel web PCT girder manufactured by applying one embodiment of a method for manufacturing a corrugated steel web PC girder according to the present invention. FIG. 5 is a cross-sectional view of the corrugated steel web PCT girders shown in FIG. 4. FIG. 6 is a perspective view of the corrugated steel web PCT girders shown in FIG. It is a side view which shows the corrugated steel plate arrangement | positioning process of an Example. It is a side view which shows the corrugated steel plate joint process of an Example. It is a side view which shows the concrete placement process of an Example. It is a side view which shows the segment separation process of an Example. It is a side view which shows the segment connection process of an Example.

Explanation of symbols

1 Corrugated steel web PCT girders 10, 11, 12 Corrugated steel 11a, 12a Holes 11b, 12b Upper end 11c, 12c Lower end 13 Clearance 21, 22 Upper and lower floor slab concrete 30 Temporary attachment plate 41, 42 Bolt 51, 52 Partition plate 60 Formwork 61, 61a, 61b Upper floor formwork 62, 62a, 62b Lower floor formwork 63 Formwork frame 70 Main plate

Claims (2)

  When manufacturing PC girder segments using corrugated steel webs, corrugated steel sheets of segments adjacent in the longitudinal direction of the girder are butted together through a gap and joined with temporary adhering plates. A method for manufacturing a corrugated steel web PC girder, characterized in that a frame is attached and concrete is placed with a partition plate thinner than the gap between adjacent upper and lower floor slab forms.   The method of manufacturing a corrugated steel web PC girder according to claim 1, wherein the difference between the gap dimension and the thickness dimension of the partition plate is equal to or slightly larger than the longitudinal contraction amount of the slab concrete. .

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