JP3720837B1 - Extrusion erection method - Google Patents

Abstract

An extrusion erection method using a corrugated steel sheet web is provided in which a lightweight steel structure frame is constructed at the stage of extrusion, and upper and lower floor slab concrete is cast after spanning.
An extrusion frame 15 having a reinforcing frame for reinforcing corrugated steel sheets and a lower floor slab concrete form is assembled in a production yard 40, and the extrusion frame 15 is sequentially connected to be extruded between bridge piers. After completion, the lower floor slab concrete is placed on the extruded frame 15 and prestress is introduced. Then, the upper floor slab concrete 31 is placed and prestress is introduced, and the final prestress is applied to the entire bridge body. Give.
[Selection] Figure 1

Description

  The present invention relates to a method for extruding a PC box girder bridge using a corrugated steel web.

  The PC bridge extrusion construction method has the advantage that it is not necessary to use the space under the girder at all. It is effective for the construction of bridges in mountain valleys where it is difficult to build vents in addition to overpasses and overpasses. It is a construction method.

However, it has the following disadvantages.
(1) Extrusion equipment is excessive because it pushes out heavy concrete girders.
(2) Since the girders during extrusion receive bending moments that alternate between positive and negative, it is necessary to make the PC steel material arrangement almost close to the axial force, and the bending strength improvement effect due to the eccentric arrangement of the PC steel material cannot be exhibited. .
(3) Also, the ratio of the girder height to the span is greater than other methods.

  Therefore, there is a problem that the bridge is disadvantageous in terms of economy as compared with other construction methods.

  There is a technique for constructing an extruded bridge by connecting concrete blocks (see, for example, Patent Document 1). This technology is a technology that extrudes a concrete block that is wider than the girder in a state where the width direction is up and down.

  In addition, there is a technique using a bridge girder support structure that resists bending stress generated in a bridge girder by an extrusion construction method of a prestressed concrete bridge (see, for example, Patent Document 2).

  This technology is a technology that eliminates the unbalance caused by complicated fluctuations in the tensile force of the temporary diagonal members during the extrusion process such as cable-stayed bridges.

  Moreover, in the extrusion method of the reaction force concentration system using a jack, a tensile steel material, etc., there exists a technique which eliminates that a tensile steel material droops greatly ahead of the main girder production yard (for example, refer patent document 3).

  The conventional techniques described above are ordinary box-type concrete bridge extrusion construction methods. On the other hand, there are techniques for extrusion construction of steel-concrete composite PC structure bridges using corrugated steel sheets as webs (for example, patent documents). 4).

This technology is to produce and extrude a composite PC bridge consisting of concrete upper and lower floor slabs and steel plate webs in a one-frame mold installed at the extrusion position. This is a technology in which a tensioned PC steel material is stretched to produce a block to which tension is applied, and this is sequentially extruded.
JP 63-261005 (page 2-3, FIG. 7) Japanese Unexamined Patent Publication No. 2000-144637 (page 2-3, FIG. 1) JP 2003-138522 A (page 2-4, FIG. 1) Japanese Patent Laid-Open No. 2004-19126 (page 2-3, FIG. 4)

  The present invention is an extrusion construction method of a PC box girder bridge using a corrugated steel web similar to the technique shown in Patent Document 4, but is a completely different technique from Patent Document 4 and is a lightweight steel at the stage of extrusion. It is an object of the present invention to provide an extrusion construction method for a PC box girder bridge using a corrugated steel sheet web in which a structural frame is constructed between spans and then upper and lower floor slab concrete is placed.

The present invention has been made to solve the above-described problems, and is an extrusion erection method characterized by taking the following technical means. That is, the present invention uses a corrugated steel block provided with a reinforcing frame and a lower floor slab concrete form for reinforcing a corrugated steel sheet in the construction of a PC box girder bridge using the corrugated steel sheet web. Connect, assemble the extrusion frame, push the extrusion frame to install between single diameters or multiple diameters, and after completing the installation, cast concrete into the lower floor slab concrete formwork for each span. Then, prestress is introduced, and then the upper floor slab concrete form carrier carriage is placed on the extruded frame, the upper floor slab concrete is placed and prestress is introduced, and the final prestress is applied to the entire bridge body. An extrusion construction method characterized by applying stress.
Here, the reinforcing frame refers to a structure made of a member that reinforces the corrugated steel plate so that the corrugated steel plate can be extruded and built as an extruded frame of the steel structural frame. For example, a reinforcing material that connects the upper ends of the corrugated steel plates And a brace etc. for reinforcing this.
Further, the upper floor slab concrete formwork carriage is a simple work carriage that runs on an extrusion frame in which lower floor slab concrete is placed and prestress is introduced, and is a mold for placing the upper floor slab concrete. It is a movable carriage carrying a frame.

  The present invention provides a novel cross-linking method in which the advantages of the conventional PC bridge extrusion construction method are followed as they are, and all the disadvantages are improved.

According to the present invention, compared to the conventional PC bridge extrusion construction method,
(1) Since the bridge body at the time of extrusion construction is only the extrusion construction frame, the load on the extrusion bridge body is significantly reduced in weight.
(2) Since the concrete can be placed and the PC steel can be tensioned after the extruded frame is in a continuous girder state, the eccentric effect (effect by bending up) of the PC steel can be used effectively.
(3) Furthermore, it is possible to lower the height of the girder as compared with the prior art, and it is possible to perform the extrusion work with a long diameter.
(4) As a result, economical bridge construction is possible.
There is an excellent effect.

  The present invention, for example, covers the advantages of both by exquisitely combining the extrusion construction of a conventional full-section PC box girder and the technique of extruding only a steel girder and constructing a slab by moving support. This eliminates the disadvantages and greatly increases the effects. In addition, the construction of the lower floor slab concrete applied the PC composite floor slab construction technology.

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

FIG. 2A is a front view of the corrugated steel block 10 used in the present invention. A plurality of rows (two rows on the left and right in the figure) of corrugated steel webs 11 are provided with steel flanges 12 and 13 at the upper and lower ends, respectively. Corrugated steel web 11 of the plurality of rows is reinforced by a reinforcing framework consisting of breath 22 for reinforcing it with reinforcing material 21 that connects the upper end. The lower end of the corrugated steel web 11 are connected by a combined prestressed concrete (PC) plate and a lower flange 13. This PC plate 23 becomes a formwork for placing the lower floor slab concrete.

  FIG. 2B shows a state in which the lower floor slab concrete 24 is placed. A lower floor slab concrete 24 is cast on the PC plate 23 to form a composite lower floor slab of the PC plate 23 and the cast concrete.

FIG. 2C is a cross-sectional view (front view) of the corrugated steel web bridge 30 after the upper floor slab concrete 31 is constructed. The upper floor slab concrete 31 is placed in a mold suspended from an upper floor slab concrete form carriage, for example, a wagen work carriage or a simple form holding and moving carriage. The upper floor slab concrete is prestressed by the PC tendon 32, and the connected upper floor slabs are integrated. In FIG. 2C, the reinforcing frames such as the reinforcing members 21 and 22 shown in FIG. 2A are removed.

  Next, an embodiment of the present invention will be described with reference to FIGS. 1 (a) to 1 (g).

1 (a) to 1 (g) are explanatory views (process drawings) showing an extrusion erection method according to an embodiment of the present invention.
(1) As shown in FIG. 1A, the corrugated steel block 10 is sequentially connected in the production yard 40 to assemble the extrusion frame 15. At this time, as shown in FIG. 2A , the reinforcing material 21 and the brace 22 that connect the upper ends of the corrugated steel plates are attached as the reinforcing frame, and the PC plate 23 that is the lower floor concrete formwork is attached to the lower flange 13. The steel flanges 12 and 13 of the corrugated steel sheet 10 adjacent to each other in the longitudinal direction are connected to the adjacent steel flanges by high-strength bolts or welding, respectively, and can sufficiently resist the bending in the longitudinal direction of the extrusion frame 15 at the time of extrusion. Like that. A hand girder 41 is attached to the distal end of the extrusion frame 15.
(2) In this state, as shown in FIG. 1 (b), the extrusion erection frame 15 is advanced in the direction of the arrow 42 to perform the extrusion erection.
(3) The above is repeated and the extrusion construction of the extrusion construction frame 15 is completed on the piers 50a to 50d as shown in FIG. Up to the above stage, each corrugated steel block 10 of the extrusion frame 15 is in the state shown in FIG.
(4) As shown in FIG.1 (d), the cross beam 25 and the lower floor slab concrete 24 are laid, and the prestress introduction | transduction 26 is performed to a required location. FIG. 2B described above shows a cross section of the corrugated steel block 10 at this stage.
(5) Place the upper floor slab concrete 31. Since it is only necessary to construct the upper floor slab, a simple working carriage used for the construction of the steel slab girder can be used. Depending on the scale of the bridge, it is also optional to lay the upper floor slab concrete 31 as shown in FIGS. 1 (e) and 1 (f). Prestress is sequentially introduced into the placed upper floor slab concrete 31. As a result, the corrugated steel block 10 is in the state shown in FIG.
(6) Finally, as shown in FIG. 1 (g), necessary prestress is applied to the bent-up steel material 60.

In the extrusion erection method PC Hakoketakyo using corrugated steel of the present invention, assembled only corrugated steel and P C plate for the lower deck mold in fabrication yard, and form an extrudable erection frame, the lightweight extruded Extrude the installation frame. According to the method of the present invention, the load on the bridge body during extrusion is overwhelmingly lighter than in the prior art. For example, the load of the bridge body at the time of extrusion is about 1/5 to 1/6 as compared with a conventional PC box girder.

  For an extruded frame where the extruded frame is in a continuous girder state. Since the lower floor slab concrete and the upper floor slab concrete are sequentially cast, the concrete load is supported by a continuous girder and the construction is easy. Further, since the PC steel material can be arranged and strained in a bent-up shape, the eccentric effect of the PC steel material can be used effectively, and economical bridge construction becomes possible.

  For example, the applicable span length can be increased to about 60 to 70 m compared to about 30 to 50 m in the conventional PC box girder, and the girder span ratio (H / L) is in the conventional PC box girder. Compared to about H / L = 1/16, it can be reduced to about H / L = 1/20.

It is process explanatory drawing of an Example. It is process explanatory drawing of an Example. It is process explanatory drawing of an Example. It is process explanatory drawing of an Example. It is process explanatory drawing of an Example. It is process explanatory drawing of an Example. It is process explanatory drawing of an Example. It is a figure which shows the cross-sectional shape of the corrugated steel block according to a construction stage. It is a figure which shows the cross-sectional shape of the corrugated steel block according to a construction stage. It is a figure which shows the cross-sectional shape of the corrugated steel block according to a construction stage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Corrugated steel plate block 11 Corrugated steel sheet web 12, 13 Steel flange 15 Extrusion frame 21 Reinforcement material 22 Breath 23 PC plate 24 Lower floor slab concrete 25 Cross girder 26 Prestress introduction 30 Corrugated steel web bridge 31 Upper floor slab concrete 32 PC tension material 40 Production Yard 41 Hand Girder 42 Arrow 50a-50d Bridge Pier 60 Bending Steel

Claims (1)

  When installing PC box girder bridges using corrugated steel webs, corrugated steel blocks equipped with reinforcing frames and lower floor slab concrete formwork to reinforce corrugated steel are used, and these are connected sequentially in the production yard, and extruded. Assemble the frame, extrude the extrusion frame and install it between single diameters or multiple diameters, and after completion of installation, for each diameter, place concrete in the lower floor slab concrete formwork to prestress Introducing, then placing the upper floor slab concrete form carrier carriage on the extruded frame, placing the upper floor slab concrete and introducing prestress, and further applying final prestress to the entire bridge body A featured extrusion erection method.

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