JPH0517913A - Form timbering for arch concrete depositing - Google Patents

Abstract

PURPOSE:To form a form timbering in an arch-shaped truss structure suited to the depositing of arch concrete which has a long span or is flat. CONSTITUTION:A pair of semiarch-shaped divided trusses 3 being so long as the length of the bisected span of an arch concrete 2 are formed, and the each lower end of the divided truss 3 is joined to an abutment 1, and the upper ends of the divided trusses 3 are mutually adjoined, and supported by posts 6 risingly provided on the ground 5 for forming a form timbering having truss structure wholly formed in an arch-shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a form support method applied to the construction of arch concrete in arch bridges and the like.

[0002]

2. Description of the Related Art Formwork support applied to the construction of arch concrete, such as in arch bridges, is described in, for example, Japanese Patent Laid-Open No. 63-272861. The construction of trusses has come to be carried out, and the workability and economic efficiency have been significantly improved.

However, even if the above-mentioned form supporting work is applied to a long span as it is, it will become a large-scale structure and its advantages will be lost. Therefore, as described in JP-A-2-240311,
Formwork supporting work has been developed by combining trusses and pillars formed by dividing, and it can be applied to construction of long span or flat arch concrete.

[0004]

However, when the pillar supporting the above-mentioned divided truss is erected on the ground which is strong like rock and has no possibility of sinking, the load between the truss and the pillar is increased. Allocation will be done almost as designed, so there is no problem.

However, the pillars cannot always be erected on a solid ground, and the pillars may sometimes sink a little when concrete is placed due to the condition of the ground and the convenience of construction. In that case, the truss will be overloaded, exceeding the design value.

In order to prevent this, it is necessary to correct the sunken column to the original height and restore the load sharing to the column to the design value, but such height adjustment of the column is very troublesome. Not only that, but it also makes it difficult to evenly distribute the load to the support work.

The present invention has been made in order to solve the above problems, and when the prop is slightly submerged, the load distribution between the truss and the prop is corrected and equalized without adjusting the height of the prop. It is intended to provide a formwork support work that can be achieved.

[0008]

The structure of the present invention for achieving the above object will be described with reference to the drawings corresponding to the embodiments. Sano split trusses 3 and 3 are formed,
The lower end of each of the divided trusses 3 is connected to the abutment 1, and the upper ends of the respective divided trusses 3 are adjacent to each other and are separately supported 7 by columns 6 standing on the ground 5. Is.

[0009]

In the formwork support work in which the upper ends of the split trusses 3 are supported by the support columns 6, assuming that the support columns 6 are erected on the ground that is not strong, when the concrete is placed, the support columns 6 slightly sink. I have something to do. In this case, the upper end of the split truss 3 follows the sinking of the support column 6 and descends, and the load distribution between the split truss 3 and the support column 6 is maintained at a value almost as designed. It is possible to prevent an excessive load from being applied to.

Since the subsidence of the pillar 6 is usually not noticeably large, the amount of deformation of the formwork 8 following it is also small, and it does not affect the placed arch concrete 2. Almost none.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of one embodiment of the present invention,
1 is an abutment for erection of arch concrete 2 (may be a pier), 3 is span of arch concrete 2 of about 2
A divided truss formed into divided lengths, the upper chord of which is formed in a curved shape along the arc surface of the arch concrete 2. The two split trusses 3 are rotatably supported by the load receiving pins 4 and 4 at their lower ends on the abutments 1 and 1, respectively, and their upper ends are adjacent to each other. The upper end of 6 is rotatably connected and supported by the load receiving pins 7 and 7, and the whole arch-shaped form support is constructed as a whole. An arch-shaped frame 8 is installed throughout the upper surface of the frame support work.

As shown in the enlarged view of FIG. 2, the split truss 3 has a structure in which a curved upper chord member 9 and a lower chord member 10 formed to be shorter than the upper chord member 9 are connected by a large number of diagonal members 11 or the like. The lower end portion is pivotally supported by a load receiving pin 4 on a bracket 13 of a support 12 fixed to the abutment 1. On the other hand, on the ground 5 at the center between the abutments 1 and 1 on which the above-mentioned divided trusses 3 and 3 are erected, pillars 6 and 6 are vertically erected adjacent to each other, and the upper end portion and The upper end is connected by a load receiving pin 7, and the columns 6 and 6 have a vertical load of 1 which is applied to each of the divided trusses 3 and 3 via the frame 8.
The division will be shared.

The formwork supporting structure of the above construction is provided in a plurality of rows at a predetermined interval in the depth direction of the arch concrete to be constructed, and they are connected to each other using connecting rods (not shown).
Further, the mold 8 is erected via support tools 14 and 14 such as bolts and flaps attached to the upper chord members 9 and 9 of the above-described frame support of the frame.

In the above embodiment, the split truss 3 has the upper chord member 9 and the lower chord member 10 which are curved, but the respective members 9 and 10 can be formed in a straight shape. In that case, in order to make the formwork 8 arch-shaped,
The size of the support 14 may be different at each support point, or the support height of the support tool 14 may be changed.

[0015]

As described above, according to the present invention, the truss of the arch-shaped frame supporting work installed between the abutments is divided into two,
Since each divided truss is individually supported by abutments and columns, it can be applied as a support work for large spans or flat arch concrete without increasing the size of the truss, and a support facility Expected to reduce costs and improve construction efficiency.

Further, even if the pillars supporting the split trusses are slightly submerged in a situation such as the ground, the subdivision trusses follow the subdivisions separately, so that the load distribution is maintained almost as designed. , It is possible to prevent excessive load on the split truss, and the economical efficiency of supporting work is improved as a whole.
It has an excellent effect.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a support work of the present invention.

FIG. 2 is an enlarged front view showing a substantially half part of the support work of the present invention.

[Explanation of symbols]

 1 Leg stand 2 Arch concrete 3 Dividing truss 4 Load receiving pin 5 Ground 6 Pillar 7 Load receiving pin 8 Formwork 9 Upper chord member 10 Lower chord member 11 Diagonal member 12 Supporting base 13 Bracket

Claims (1)

What is claimed is: 1. A split truss having a length obtained by dividing the span of arch concrete into two is formed, the lower ends of the split trusses are connected to an abutment, and the upper ends of the split trusses are adjacent to each other. Form support for arch concrete construction, which is supported separately by upright columns on the ground.