JPH0718623A - Box girder bridge - Google Patents

Abstract

PURPOSE:To reduce a cost and to improve workability by vertically erecting posts in a region equivalent to a partition wall position instead of the conventional partition wall to be provided in the interior of a box girder bridge. CONSTITUTION:In a box girder bridge, posts 5 are vertically erected instead of a partition wall provided in the central part of the conventional bridge 1. Subsequently, while two partition walls are provided heretofore in the central part to form three chambers, instead of the partition wall, the posts 5 are erected in the position, and in this case, a rectangular section is suitable because the shearing force applied to the girder is also shared by the posts 5. Thus, the thickness of a member can be reduced as small as possible, and as the worker can freely come and go in the interior, the workability can be improved, and an outer cable can be easily disposed. Furthermore, an inner formwork can be simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a box girder bridge, and more particularly to improvement of a multi-room type box girder bridge.

[0002]

2. Description of the Related Art A conventional box girder bridge 1 of this type is as shown in FIGS. 11 (a) and 11 (b).
Many have one room 2, but the width of the bridge is 1
When the width is wider than 0 m, the span becomes long in the lateral cross-section design, which increases the thickness of necessary members, which is uneconomical with only one room. For this reason, generally, as shown in FIGS. 11C and 11D, a two-chamber type box girder bridge 1 having a partition wall 3 in the center and chambers 2 and 2 on the left and right sides thereof is used. However, when manufacturing this two-room type box girder bridge 1, the area of the inner formwork increases, so the box girder bridge 1
It is very uneconomical because of the high equipment cost for manufacturing. In addition, since the worker cannot freely move between the left and right chambers 2 and 2 during the erection, the adjacent box girder bridges 1 are assembled together and the outer cable (not shown) installed inside the box girder bridge is not shown. There is a problem that the workability such as the arrangement work) is extremely deteriorated.

In order to allow the two chambers 2 and 2 to move freely, as shown in FIG. 12, the box girder bridge 1 is provided.
It is also known that the struts 4 and 4 are arranged in an eight shape in the chamber 2 and the upper ends of the struts are joined together. Therefore,
The struts 4 and 4 are intended to maintain the rigidity of the box girder bridge 1 by obliquely installing from the inner ends of the lower slab 1b of the box girder bridge 1 toward the center of the inner side of the upper slab 1a so that the struts 4 and 4 are held together. Therefore, the struts 4 and 4 are always used as a pair of two struts, and there is a defect that the material is uneconomical in combination with the slant. Further, when arranging the outer cable in the box girder bridge 1, there is a defect that the slats 4 and 4 that are obliquely arranged interfere with the free arrangement of the outer cable.

Therefore, at the time of erection of the box girder bridge, workers can freely move in and out of the box girder bridge, and it is economical and does not hinder the work of arranging the outer cable. A technical problem to be solved in order to obtain a box girder bridge excellent in workability arises, and an object of the present invention is to solve the problem.

[0005]

The present invention has been proposed in order to achieve the above object, and instead of the partition wall to be provided inside the box girder bridge, the partition wall equivalent portion,
It provides a box girder bridge in which columns are erected vertically.

[0006]

According to the present invention, instead of the conventional partition wall to be provided inside the box girder bridge, a column is vertically erected at a portion corresponding to the partition wall. The member thickness can be made as thin as possible, which is economically advantageous, and the inside and outside of the box girder bridge can be freely moved. Since it also has the advantage of the box girder bridge and replaces the conventional partition wall, the cross section can be made even smaller and lighter, and at the same time the inner formwork can be simplified, and
Since there is no hindrance in the work of arranging the outer cable in the box girder bridge, the workability is improved and the cost is reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. The same reference numerals are used for the symmetric parts of the conventional box girder bridge. In the figure, a box girder bridge 1 according to the present invention
In place of the partition wall 3 provided in the central portion of the conventional box girder bridge 1, a pillar body 5 is vertically erected. As a result, one column 5 or one column on the left and right sides is provided upright in the substantially central portion of the chamber 2, and the chamber 2 substantially forms one chamber.
However, in the conventional case where two partition walls are provided in the central portion and three chambers are formed, the pillars 5 and 5 are erected in place of the partition walls as shown in FIG. The chamber may be formed substantially as one chamber. However, in this case, the columns 5 and 5 also share the shearing force applied to the girder, so that the cross-sectional shape is preferably rectangular. In this way, workers can freely move in and out of the room 2, so that workability such as arrangement work of the outer cable (not shown) in the box girder bridge 1 is improved. Moreover, the pillar 5
Since it is erected vertically, the material cost can be reduced and the inner formwork can be simplified. Therefore, it was found that the present invention has superior advantages over the conventional example, as shown in the following table of the calculation results at the time of design.

[0008]

[Table 1]

The (a) type and (b) type shown in Table 1 above are single-chamber type box girder bridges, (c) and (d) types are two-chamber type box girder bridges, and (e) type is the present invention. It is calculated for the box girder bridge. From the table, it can be confirmed that the type (e) according to the present invention is most advantageous. or,
The type (e) is also the same as the type (a) in terms of form length.
It is a little inferior to the room type box girder bridge, but it can be seen that it has the most advantage over other types.

The pillar 5 according to the present invention can be formed of cast-in-place concrete or precast concrete, and can also be formed of steel frame, and the material can be freely selected. Further, the present invention is naturally applicable not only to cast-in-place concrete box girder bridges but also to precast concrete box girder bridges.

As a method of installing the pillar body 5,
The precast concrete pillars 5 may be installed at the same time or after the installation of the box girder bridge 1, or may be installed by on-site casting. In addition, the box girder bridge 1 shown in the embodiment diagram of FIG.
Is a beam member provided with convex portions 6 and 6 facing each other in the width direction of the substantially central portions of the upper slab 1a and the lower slab 1b, and the pillars 5 and 5 are provided between the convex portions 6 and 6. The slabs are arranged upright, but as shown in FIG. 4, the upper and lower slabs 1a and 1b.
It is also possible that the reinforcing bars P, P ... For the beam are arranged at the positions of the convex portions 6 and 6 while the thickness of the same remains constant to function as a beam member. In this case, the amount of rebar increases, but the cross section is further reduced, and the mold can be easily assembled.

When the column body 5 of the present invention is set up in the box girder bridge 1 afterward, it is possible to use the column body 5 which can be expanded and contracted. That is, concave portions 7 and 7 are provided on the surfaces of the convex portions 6 and 6 provided on the upper and lower slabs 1a and 1b in the box girder bridge 1, and the upper and lower ends of the pillar 5 are inserted into the concave portions 7 and 7, respectively. Since they are joined together, the column 5 is used as a stretchable structure. In this case, the concave portions 7, 7 are
It is also possible to embed the a and 7a and insert the columnar body 5 into the a and 7a to form a hinge connection so that the beam members of the upper and lower slabs 1a and 1b are not rigidly connected.

Further, since the column 5 is set up by the human power without using a heavy machine such as a crane because it is set up in the box girder bridge 1, it is possible to use a lightweight member as much as possible. For example, as shown in FIG. 6, the pillar 5 is formed of a steel pipe pillar 5a and a bolt 8 instead of precast concrete, and a female screw portion is formed on the inner surface of the steel pipe pillar 5a. The upper portion of the bolt 8 that is screwed to the screw portion may be screwed to the female screw portion, and the nut handle 9 may be rotated to adjust the vertical length of the pillar body 5. Therefore, the pillar body 5 is shortened in advance and the lower end portion thereof is set up in the recessed portion 7 provided in the lower slab 1b, and the nut handle 9 is rotated to make the upper end portion of the steel pipe pillar 5a into the upper slab. It is erected by abutting against the concave portion 7 provided in 1a.

The column 5 is set up at the time of the box girder bridge 1.
However, the upper slab 1a is bent by its own weight when the mold is removed from the mold, so that when the adjacent box girder bridges 1 are joined, the pillars are immediately removed from the mold. Allow 5 to be installed. In addition, the expandable column 5 shown in FIG.
Is an upper threaded steel rod 11 at the top and bottom of the threaded joint 10, respectively.
And a lower threaded steel rod 11a are screwed in. Then, by rotating the threaded joint 10, the upper and lower threaded steel rods 11 and 11a move toward or away from each other to adjust the length of the column 5 to adjust the embodiment of FIG. As shown in the figure, it is erected between the upper and lower slabs 1a and 1b.

Furthermore, FIG. 8 shows another embodiment. In the figure, the column 5 is formed by filling the upper steel rod 12 and the lower steel rod 12a, and the grout material 14 in the sleeve 13 that covers the space between them, and by interposing the shim 15. The upper and lower steel rods 11 and 11a are interposed between the upper and lower slabs 1a and 1b to adjust the length, and the grout material 14 is fixed by hardening. Further, precast concrete may be used in place of the upper and lower steel rods 12 and 12a.

In the above embodiment, the precast box girder bridge 1 was described as symmetrical, but the present invention can be applied to the cast-in-place concrete box girder bridge 1 as long as it has a wide cross section of the conventional two-room type or more. Of course. Furthermore, FIG. 9 and FIG.
Another embodiment is shown in FIG. FIG. 9 shows a single column body 5, but FIG. 10 shows the column body 5 which is vertically divided into two.
Then, the upper end surface of the pillar body 5 of these people is anchor bolts 16,
16 is attached to the upper slab 1a. However, FIG.
In the embodiment of FIG.
6 is attached to the lower slab 1b. The length of the pillar 5 is adjusted by using the flat jack 17. At this time, in FIG. 9, the flat jack 17 is disposed at the lower end portion, and the spacing member 1 made of mortar, cement milk, rubber, hard fiber or the like is provided in the gap between the upper and lower surfaces thereof.
8 and 18 are buried.

Further, in FIG. 10, the flat jack 1 is
7 is interposed in the upper and lower divided portions, and the spacing members 18, 18 are embedded in the gap between the upper and lower surfaces thereof. Therefore,
In the illustrated example, the column 5 is made of H steel, but a steel pipe, S
It is also possible to use materials such as RC structure, RC structure and FRP material. The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified one.

[0018]

The present invention, as described in detail in the above embodiment,
Instead of the partition wall of the conventional multi-chamber box girder bridge, since the column body is vertically erected at the part corresponding to the partition wall, the member thickness can be formed as thin as possible, therefore, Advantages of a multi-room box girder bridge and the ability to move freely within the box girder bridge 1
This invention has both of the advantages of the room-type box girder bridge, improves workability, and contributes to an extremely low cost.

[Brief description of drawings]

FIG. 1 is a perspective view of a box girder bridge according to an embodiment of the present invention.

FIG. 2 is a front view of a box girder bridge according to another embodiment of the present invention.

FIG. 3 is a front view showing a beam portion of upper and lower slabs of a box girder bridge.

FIG. 4 is a front view showing the beam portions of the upper and lower slabs of the box girder bridge.

FIG. 5 is a partially cutaway front view showing a ball seat provided on a slab.

FIG. 6 is a partially cutaway front view showing another embodiment of the pillar body.

FIG. 7 is a vertical cross-sectional view showing still another embodiment of the column.

FIG. 8 is a vertical sectional view showing still another embodiment of the column.

FIG. 9 is a partially cutaway vertical sectional view showing still another embodiment of the column body.

FIG. 10 is a partially cutaway vertical sectional view showing still another embodiment of the columnar body.

11A to 11D are front views of a conventional box girder bridge, and FIG. 11E is a front view of the box girder bridge of the present invention.

FIG. 12 is a front view of a conventional box girder bridge.

[Explanation of symbols]

 1 Box girder bridge 2 Room 3 Partition wall 5 Pillar

Claims (1)

[Claims] 1. A box girder bridge characterized in that, instead of a partition wall to be provided inside the box girder bridge, a column is vertically erected at a portion corresponding to the partition wall.